Road to a Cure Pedal for PSC

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Research Grants

PSC Partners Seeking a Cure

Research Grants

PSC Partners Annual Research Grant Awards

Every year, on the recommendation of the Scientific/Medical Advisory Committee and the Board of Directors, PSC Partners Seeking a Cure chooses the most promising research projects to support. In 2009, PSC Partners Seeking a Cure awarded its first set of research grants, selected on the basis that they supported research addressing an important and novel, basic or clinical question related to PSC. For PSC Partners, this was an important milestone, an important step towards taking us closer to new treatments and an eventual cure. Since the inception of our grants program, we have awarded eight major grants in 2009, five in 2010, three in 2011, three in 2012, seven in 2013, seven in 2014, and six in 2015 for a total of $1,842,706 already allocated to promising PSC research projects. Grant awards are made on an annual basis. The deadline for submission of 2017 grant proposals is April 1, 2017. Click here for the research proposal application materials.

We thank all of our donors throughout the years who have supported our mission of raising funds to research causes, treatments and cures for primary sclerosing cholangitis. Your contributions have made these awards possible!

All research proposals are reviewed annually by the PSC Partners’ Scientific/Medical Advisory (SMAC) Committee.

Yearly Awards

Awarded in 2016

We are thrilled to announce that in 2016, PSC Partners will fund six research projects and one PSC educational project. PSC Partners received a record number of grant applications this year, from leading PSC institutions worldwide.

All of our lead investigators are of international renown and have proposed highly innovative studies to advance the diagnosis and therapy of primary sclerosing cholangitis. Each researcher has provided a lay summary for the PSC Partners community.

Macrophages in the Development of Sclerosing Cholangitis: Therapeutic Implications

Maria Eugenia Guicciardi, PhD, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA

Amount Awarded: $60,000 over two years.

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease of unknown etiopathogenesis characterized by fibrosis around large and small bile ducts. Compelling evidence supports a major functional role for macrophages in liver fibrosis. We noted that interlobular cholangiocytes in human PSC express markedly reduced levels of cellular inhibitor of apoptosis protein 1 and 2 (cIAP-1 and cIAP-2), two important regulators of inflammation and cell death. In a novel murine model developed in our laboratory, injection of a cIAP antagonist (named SMAC mimetic), which induces rapid degradation of cIAP-1 and cIAP-2, into the biliary tree of mice causes an acute fibrous cholangiopathy that resembles that of PSC. Following exposure to the SMAC mimetic in vitro and in vivo, cholangiocytes upregulate several proinflammatory cytokines and chemokines, including the monocyte chemoattractant MCP-1/CCL2. Consistently, periductular accumulation of macrophages is evident in the livers of SM-treated mice and PSC patients. This project aims to test the hypothesis that cholangiocyte damage in PSC is associated with decrease in cIAP-1 and -2 cellular levels and release of pro-inflammatory chemokines, with subsequent recruitment and activation of macrophages. In particular, this project will focus on the role of TNF-related apoptosis-inducing ligand (TRAIL), a cytokine expressed by several immune cells, including macrophages (especially the pro-inflammatory M1 macrophages), in the development of sclerosing cholangitis. These studies will allow us to verify whether inhibition of macrophage-derived TRAIL can effectively prevent or attenuate the PSC-like phenotype, and could identify TRAIL as a key molecule in the initiation and/or progression of PSC, potentially providing a rationale for the development of novel therapies for this disease.

Functional microbial biomarkers in primary sclerosing cholangitis

Johannes R. Hov, MD, PhD Norwegian PSC Research Center, Department of Transplantation Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway

Amount Awarded: $60,000 over two years

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the bile ducts with no known cause. It may lead to end-stage liver disease and sometimes cancer. We have recently shown using genetic methods that PSC patients harbor a different set of microbes in the gut than healthy controls. This is an important starting point, but with the technology used so far, only a low-resolution profile of the gut microbes is available. In the present study, we want to sequence all bacterial DNA (the full “metagenome”) present in the stool of PSC patients and controls from two countries (Norway and Germany) to investigate the hypothesis that specific microbial functions are altered in the gut community. Identified altered microbial functions and subsequent altered metabolism of endogeneous or dietary substances may potentially be relevant for disease development and progression and provide new clues to disease pathogenesis and treatment. We believe that gut metagenomics is the first step in the translation of the basic knowledge of the gut microbiome to address some of the most critical clinical challenges in PSC.

Mutational profiling for therapeutic targets in PSC – associated biliary tract cancer

Tom Hemming Karlsen, MD, PhD, Norwegian PSC Research Center, Division of Surgery, Inflammatory Medicine and Transplantation, Oslo University Hospital, Rikshospitalet, Oslo, Norway

Amount Awarded: $60,000 over two years

Cholangiocarcinoma is a dreaded complication in patients with primary sclerosing cholangitis (PSC). In personalized cancer medicine, screening for clinically relevant genetic tumor alterations is increasingly used to stratify patients for targeted cancer therapy. Dedicated genetic studies in PSC-associated cholangiocarcinoma are so far missing. This also means that personalized therapeutic approaches have not been possible to consider for this group of patients. The proposed project aims to bridge this knowledge gap, by investigating known cancer genes in cholangiocarcinoma tumor tissue from a large number of PSC patients. Pilot data from Oslo and Heidelberg shows promising results, and the funds from PSC Partners will be used to determine the validity of findings in many more samples from other German centers, Sweden, Finland, the Netherlands, Poland, the UK and the US.

The Enterohepatic Metabolome in Primary Sclerosing Cholangitis

Steven P. O’Hara, PhD, Assistant Professor of Medicine and Biochemistry/Molecular Biology, Mayo Clinic, Rochester, MN, USA

Amount Awarded: $60,000 over two years

Emerging data, including work from our laboratory and clinical research group, suggest fundamental disease associated mechanisms in primary sclerosing cholangitis (PSC) that are centered on molecules derived in the gut and brought to the liver through portal circulation (gut-liver axis). The gut-liver axis has been proposed to play a significant role in the initiation, progression, and adverse clinical events associated with PSC; however, this has not been directly tested to date. Our goal is to determine whether there are differences in the metabolites (proteins, fats, and other chemicals) in the portal vein (which delivers blood from the intestines to the liver) and in bile between individuals with primary sclerosing cholangitis and those without PSC.  We anticipate that patients with PSC will have distinct alterations in the portal venous and bile metabolites compared to controls; and these alterations may be amenable to future therapies.

Upregulation of biliary epithelia innate immune responses in PSC

Mario Strazzabosco, MD, PhD, Department of Internal Medicine, Section of Digestive Diseases, Yale University, New Haven, CT, USA

Amount Awarded: $60,000 over two years

Primary Sclerosing Cholangitis (PSC) is a chronic inflammatory disease of the intrahepatic and/or extrahepatic biliary tract characterized by obliterative fibrosis and cholestasis. The etiology and pathophysiology of PSC remain still unclear and lack of a valid human experimental model has hampered this area of research. Association of PSC with Inflammatory Bowel Disease together with preliminary evidence showing increased responsiveness of PSC-derived cholangiocytes to endotoxins (i.e NF-kB activation, IL8 secretion, TH17 response) strongly suggest that PSC may be caused by aberrant innate immune mechanisms.

The hypothesis of this study is that the biliary epithelium of PSC patients responds with increased production of inflammatory mediators to a variety of factors released during biliary or hepatocellular damage and able to activate the innate immunity. To address our hypothesis and generate data relevant for the human disease we will use the latest advances in stem cell technology to establish two new in vitro human models of PSC, one derived from induced-pluripotent stem cells (iPSCs) and the second from human 3D liver organoids. We will compare the activation of innate immune pathways in these new models compared with primary PSC cholangiocytes isolated from liver explants and perform gene array analysis. We expect that disease-relevant mechanisms will be common to all the three models.

The results of our study will have a strong translational potential for the understanding of the pathogenesis of sclerosing cholangitis and will also generate a screening platform for new therapeutic approaches.

Development and validation of a patient-derived, disease specific, health-related quality of life (HRQoL) tool for PSC

Douglas Thorburn, MD, Royal Free Hospital, London, UK

Amount Awarded: $60,000 over two years

With limited treatment options for patients with PSC, there is an urgent need to develop new therapies. These are required to slow or stop the progression of PSC but also to treat the symptoms of disease and improve the associated quality of life. It is also important to ensure that any new treatments under evaluation are not associated with a worsening in quality of life of PSC patients. Currently there are no validated quality of life tools validated for evaluating the experience of having PSC.

The UK-PSC research collaboration is collaborating with experienced qualitative researchers and patient groups to develop a disease-specific quality of life measure for PSC and then proceed to validate it internationally in collaboration with leading international PSC research groups via the International PSC Study Group. This international validation is crucial given the rarity of PSC and the need to recruit patients into interventional clinical trials across continents.

Development will take place over three to five years, involving the identification of relevant issues for patients through scientific literature review and in-depth interviews with patients, refining and validation of the questionnaire in a large patient survey, and finally evaluation in PSC patients to ensure a scientifically sound, valid, reliable and precise tool. The team will work with the relevant regulatory authorities to ensure that the new tool is approved and suitable for multicenter international clinical trials.

Patient education in PSC; Development of a 3D-animation

Cyriel Ponsioen, MD, PhD, Academic Medical Center, Amsterdam, Netherlands

Amount Awarded: $9,960 over one year

Primary sclerosing cholangitis (PSC) is a very complex disease. For patients it can take a long time to understand what exactly is happening. Despite explanation by clinicians, patients knowledge is often lacking.

It is important for patients to understand the basic principles of PSC. By knowing these, they can participate more and better in the treatment process. Well educated patient have been shown to have better clinical outcomes.
The internet is providing a lot of medical information for patients, however the reliability of this information is doubtful. Until now there is no video or animation on the internet providing proper information about PSC.

In this project we want to develop a 3D- animation with information about PSC. It will be especially designed for patients. Pathophysiology, diagnosis and treatment will be discussed. A voice-over will give a clear explanation during the video.
A 3D-animation is ideal to educate patients. First of all, visual information is easy to understand and the three-dimensional aspect makes it even clearer. Secondary, it is very easy to spread (via the internet). Also, with a little extra effort an extra voice-over language can be added, whereby people can get information in their own language.

Input and feedback from patient representatives from PSC partners seeking a cure and patients from the AMC will be used to optimize the content of the video.

A survey will be administered to a group of patients one month prior to the release of the video to assess their knowledge. This survey will also contain questions on the perception and satisfaction of their knowledge. After watching the video the same questionnaire will be administered. A control group of patients will complete the second questionnaire without watching the video first. Subsequently, knowledge improvement and satisfaction can be measured.

Awarded in 2015

In 2015, PSC Partners has funded five research studies. The recipients of the awards are Jessica Allegretti, MD, MPH, Brigham and Women’s Hospital, Boston, MA. Rodrigo Liberal, MD, PhD, Institute of Liver Studies, King’s College London School of Medicine at King’s College Hospital, London, UK. Ramille Shah, PhD, Department of Materials Science and Engineering, Department of Surgery – Transplant Division, Northwestern University, Chicago, IL. Rinse K. Weersma, MD, PhD, Department of Gastroenterology and Hepatology, University of Groningen and University Medical Centre Groningen, the Netherlands. Weici Zhang, PhD, Division of Rheumatology, Allergy and Clinical Immunology, University of California School of Medicine, Davis, CA.

All of our lead investigators are of international renown and have proposed highly innovative studies to advance the diagnosis and therapy of primary sclerosing cholangitis. Each researcher has provided a lay summary for the PSC Partners community.

Fecal microbiota transplantation for the treatment of primary sclerosing cholangitis

Jessica Allegretti, MD, MPH, Brigham and Women’s Hospital, Boston, MA.

Amount Awarded: $60,000 over two years.

Primary sclerosing cholangitis (PSC) is a progressive, chronic cholestatic liver disease characterized by inflammatory and fibrotic destruction of the intrahepatic and/or extrahepatic bile ducts. PSC will progress to biliary cirrhosis, portal hypertension and liver failure. In up to 90% of patients, ulcerative colitis or Crohn’s disease will also be present. Medications used for the treatment of ulcerative colitis have not been effective in reducing inflammation or bringing about remission in PSC. Currently there is no medical therapy that has been shown to be effective in PSC and no therapy has won FDA approval for this indication.

It has been postulated that bacterial components may stimulate an aberrant immune response resulting in the perpetuation of the biliary inflammation seen in PSC. Bacteria gain access to the liver and biliary tree through translocation across an abnormal and inflamed intestinal mucosa into the portal venous system. Animal models have demonstrated that an enteric dysbiosis can lead to hepatobiliary inflammation with features similar to PSC.

Preliminarily we have found that patients with PSC have an altered bile acid composition compared to non-cholestatic controls. Our central hypothesis is that for patients with PSC, fecal microbiota transplantation (FMT) will correct an altered bile salt profile resulting from a dysbiosis that has led to hepatobiliary inflammation and will therefore improve LFTs and slow progression to cirrhosis. Assessing the effects of FMT in this population will allow us to better understand the microbial contribution to the pathology of this disease.

2016 Update

Our study assessing fecal microbiota transplantation (FMT) for the treatment of PSC is well underway and still actively recruiting. To date we have enrolled 5 patients with plans to enroll 5 more patients with early stage PSC and concurrent inflammatory bowel disease. Our central hypothesis remains that for patients with PSC, FMT will correct an altered bile salt profile resulting from a dysbiosis that has led to hepatobiliary inflammation and will therefore improve LFTs and slow progression to cirrhosis. Among the 5 patients enrolled, 2 have completed the treatment and sample collection portion of the study, 2 are still undergoing sample collection and one has recently been enrolled and screened. Even with the limited amount of data we have to date, we are already seeing a positive trend regarding decreasing alkaline phosphatase levels after FMT. We are encouraged by these preliminary results and are excited to continue recruitment.

Entero-hepatic trafficking of lymphocytes in the pathogenesis of juvenile onset autoimmune sclerosing cholangitis

Rodrigo Liberal, MD, PhD, Institute of Liver Studies, King’s College London School of Medicine at King’s College Hospital, London, UK.

Amount Awarded: $60,000 over two years.

Primary Sclerosing Cholangitis (PSC) is a chronic inflammatory liver disease characterized by progressive bile duct destruction.  In children and young adults, sclerosing cholangitis is often associated with florid autoimmune features, including high immunoglobuli G (IgG) levels, elevated autoantibody titres, and interface hepatitis on liver biopsy. This AIH/sclerosing cholangitis overlap syndrome, called autoimmune sclerosing cholangitis (ASC) has the same prevalence as autoimmune hepatitis in the juvenile population. Since ASC is associated with inflammatory bowel disease (IBD), lymphocytes of intestinal origin might be involved in its development, as suggested for PSC.

The link between the liver and bowel disease remains speculative. One of the most fascinating hypotheses accounting for this association is that long-lived memory cells effectors of damage, primed in the lymphoid tissue of the inflamed gut, reach and circulate through the liver initiating and perpetuating hepatic autoimmunity, which can persist even when intestinal inflammation has subsided.

Recirculation of T lympocytes from the gut to the liver is dependent on the β7 family of integrins, with the α4 subtype governing exit from the blood stream and the αE being responsible for localization within the intestinal epithelium. Some of these cells may persist as long-lived memory T cells after resolution of IBD, therefore providing an explanation for the sometime independent courses of bowel and liver disease.

This project will investigate the role of entero-hepatic lymphocyte recirculation in the pathogenesis of ASC. Specific aims are to: 1) investigate whether lymphocytes of gut origin are present in the inflammatory liver infiltrate of patients with ASC and characterize their immunological function in terms of cytokine production/secretion; 2) investigate the frequency and phenotype of peripheral blood and gut lamina propria T cells in patients with ASC; 3) examine the role of the α4β7/MadCAM-1 (ligand of α4β7) and αEβ7/E-caderhin (ligand of αEβ7) pathways in the trafficking of pathogenic lymphocytes from the gut to the liver.

Results from phase II/III studies on the use of monoclonal antibodies targeting the α4- and αEβ7 integrins in IBD are very promising. Whereas ‘standard’ biologic therapy is traded with the risk of infection and other side-effects, a Cochrane review pooling all four vedolizumab (a therapeutic anti-α4β7 monoclonal antibody) studies has shown no difference in adverse events, including infections, in comparison to placebo. The benefit observed in isolated IBD may translate to patients with liver disease, such as PSC and ASC, if the pathogenic hypothesis discussed herein is supported by our studies.

2016 Update

In children and young adults primary sclerosing cholangitis (PSC) often presents with symptoms and signs that suggest an autoimmune process, including high IgG levels, elevated autoantibody titre, and interface hepatitis on liver biopsy. This autoimmune hepatitis/sclerosing cholangitis overlap syndrome, called autoimmune sclerosing cholangitis (ASC) has the same prevalence as autoimmune hepatitis. Since ASC is associated with inflammatory bowel disease (IBD), lymphocytes of intestinal origin might be involved in its pathogenesis, as suggested for PSC.

The link between the liver and bowel disease remains speculative. One of the most fascinating etiopathogenic hypotheses accounting for these observations is that long-lived effector memory cells, primed in the lymphoid tissue of the inflamed gut, recirculate through the liver initiating and perpetuating hepatic autoimmunity, even when intestinal inflammation has subsided.

Recirculation of T lympocytes from the gut to the liver is dependent on 7 family of integrins, with the α4 subtype governing exit from the circulation and αE being responsible for localisation within the intestinal epithelium. Some of these cells may persist as long-lived memory T cells after resolution of IBD, therefore providing an explanation for the sometime independent courses of bowel and liver disease.

The aim of the project is to investigate the role of an entero-hepatic lymphocyte recirculation in the pathogenesis of AILD.

During the first year of the PSC Partners grant, we have used peripheral blood mononuclear cells (PBMCs) obtained from 8 AIH patients, one ASC-IBD and 8 healthy subjects. Preliminary analysis shows elevations in gut-derived lymphocytes (namely those expressing the intergrin 7) within the circulation of AIH and ASC patients compared to healthy controls. We are currently investigating under the microscope whether b7/CCR9 expressing T cells are located in proximity to aberrantly expressed gut adhesion molecules in the liver and gut biopsies of ASC patients. Additionally, we have collected and stored for later experiments samples from 19 patients with ASC (7 females; median age 15.8; range 7.4 – 29.8 years; 9 with concomitant ulcerative colitis and 3 with Crohn disease) and 8 patients with AIH (6 females; median age 14.6; range 10.4 – 26.8 years; 1 with concomitant ulcerative colitis), as well as 10 healthy subjects. We will continue to determine the frequency and phenotype of T cells by flow cytometry and by intracellular cytokine staining.

Intrahepatic bile duct tissue engineering utilizing liver matrix and 3D bioprinting

Ramille Shah, PhD, Department of Materials Science and Engineering, Department of Surgery – Transplant Division, Northwestern University, Chicago, IL.

Amount Awarded: $60,000 over two years.

Currently the only treatment for primary sclerosing cholangitis is liver transplantation, but there remains a critical shortage of donor organs. Liver tissue engineering aims at using biomaterials designed to provide the necessary biochemical and architectural cues to guide cells to organize and synthesize new functional tissue that may lead to a viable alternative therapy for those facing end stage liver disease. However, the majority of liver tissue engineering approaches do not involve regenerating the intrahepatic bile ducts, an essential component if the engineered tissue is to be a fully functioning transplant alternative. The goal of these studies is to engineer an organized ductular network by controlling both the biochemical and architectural environment of biliary epithelial cells (e.g. cholangiocytes). We propose to control ductule formation by using 3D bioprinting to spatially pattern cells and bioactive materials in a fashion that will lead to organized hierarchical ductal structures reminiscent of native liver tissue. Future studies will incorporate 3D patterned co-cultures of cholangiocytes, hepatocytes, and blood vessel forming cells to enhance the engineered tissue functionality, vascularization, and integration with host tissue.

2016 Update

We have previously demonstrated the ability of in vitro cultured biliary epithelial cells (cholangiocytes) to form complex branching network structures within gels composed of liver matrix. Within the past year, we compared the response of cholangiocytes within the liver matrix gels to commercially available matrix gels, such as Matrigel and purified type 1 collagen, and have validated that our liver matrix gels are the only material capable of inducing the complex in vitro branching formation. Additionally, we have customized traditional methods (electron microscopy) and are developing new methods (computational 3D image analysis) to evaluate and quantify the branching structures that form in vitro.

In order to control the formation of these structures in 3D, we have also begun exploring several distinct routes to 3D-print the liver matrix gels, each of which has unique advantages. Within the next year, we expect to demonstrate a degree of control over the directionality of cholangiocyte branching formation using our 3D-printable liver matrix. Additionally, we have begun sourcing and processing mouse livers in different states of regeneration after partial hepatectomy. We anticipate that liver matrix isolated from regenerating livers will impart a beneficial effect upon in vitro cultured cholangiocytes and their duct and branch forming response.

Confirmation of rare exonic variants involved in the development of primary sclerosing cholangitis

Rinse K. Weersma, MD, PhD, Department of Gastroenterology and Hepatology, University of Groningen and University Medical Centre Groningen, the Netherlands.

Amount Awarded: $60,000 over two years.

PSC is a severe and complex disease. Both environmental factors and genetics are involved in its development and course. Several genome-wide association studies have identified genetic variants in the DNA that are associated with susceptibility to PSC.

However, a large part of the heritability for PSC is considered to be still unexplained. Part of the “hidden” heritability is thought to reside in genetic variants that occur less frequently in the general population, and are located in the exons of genes, i.e. the parts of genes that are translated into proteins. To identify such variants involved in PSC pathogenesis, the applicants have used Illumina Exome Arrays including ≈250.000 genetic variants, to genotype a cohort of 1243 PSC patients and 10038 healthy controls.

For genetic studies targeting rare variants, it is mandatory to confirm the initial findings in independent case-control cohorts to exclude false positive findings and strengthen the proof that the identified variants are indeed associated to PSC.

In this study we aim to replicate and confirm exonic variants that have been identified through the exome array analysis, in large independent cohorts of PSC patients and population matched healthy controls.

Replication genotyping will be performed using the Agena Bioscience technology (formerly Sequenom). For replication we will use DNA of PSC cases and population matched healthy controls from the USA, UK, Sweden and Belgium.

Confirmed variants will potentially give important insights in disease pathogenesis. The variants on the exome array will have direct functional implications and will therefore enable additional functional studies and hopefully targets for novel therapeutic interventions.

2016 Update

In the past year, in close collaboration with the Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany and The Wellcome Trust Sanger Institute, Hinxton, Cambridge, U.K. we have started genotyping 104 genetic variants in large independent cohorts from the USA, the UK, Belgium and Sweden. We are excited to report that this is expected to finish this month (Oct 2016).

Once we have collected the data, we will see whether we find the associations back in the independent cohorts and perform a meta-analysis to see whether these are robust genetic associations with PSC susceptibility.

Immunoglobulin glycosylation repertoire: Novel serological biomarkers of PSC

Weici Zhang, PhD, Division of Rheumatology, Allergy and Clinical Immunology, University of California School of Medicine, Davis, CA.

Amount Awarded: $60,000 over two years.

Early, accurate, specific and non-invasive biomarkers are needed for the differential diagnosis, disease monitoring, and treatment of primary sclerosing cholangitis (PSC). However, such markers are currently not available for PSC. Recent studies have implicated the significance of sugar molecules in modulating inflammatory responses. This study is directed towards investigating and determining the specificity of sugar molecules on immunoglobulin in patients with PSC. Specifically, we will apply exclusive, state-of-the-art technology using triple quadruple (QqQ) mass spectroscopy with subsequent multiple reaction monitoring (MRM) to elucidate the overall profile, composition and linkage of the sugar residues of plasma Ig glycans. This study will lay important groundwork for the discovery of new biomarkers in PSC by developing a specific Ig classifier panel and/or prognostic markers to better understand the natural history of the disease.

2016 Update

The contribution of sugar chain binding onto antibodies is gaining significant attention in autoimmune disorders. In this study, we examined the overall profile, composition and linkage of the sugar residues of plasma antibody sugar chain. Distinct sugar patterns were identified in plasma antibodies of patients with PSC when compared to PBC and healthy individuals. Next, we will evaluate sugar residue patterns in patients with IBD and other liver abnormalities. Our goal is to discover disease-specific sugar patterns of plasma antibody as biomarkers for early diagnosis and disease monitoring in PSC.

Awarded in 2014

In 2014, PSC Partners has funded six research studies. The recipients of the awards are Dr. Rudi Alberts, PhD, University of Groningen, University Medical Centre Groningen, The Netherlands. Dr. Ulrich Beuers, MD, Tygat Institute of Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, The Netherlands. Dr. Lisa Boyette, MD, PhD, Save Jon, Inc., Pittsburgh, PA. Dr. Gianna E. Hammer, PhD, Duke University, Durham, NC. Dr. Espen Melum, MD, PhD, Norwegian PSC Research Center, Oslo University Hospital, Rikshospitalet, Oslo, Norway. Dr. Guoxiang Yang, MD, PhD, University of California at Davis, Davis, CA. PSC Partners also awarded a small research grant to Mohammed Nabil Qurauishi, University of Birmingham, University of Warwick, UK, through the American Association for the Study of Liver Diseases annual program. (See all PSC Partners/AASLD awards below.)

All of our lead investigators are of international renown and have proposed highly innovative studies to advance the diagnosis and therapy of primary sclerosing cholangitis. Each researcher has provided a lay summary for the PSC Partners community.

Unraveling genetics driving PSC sub-phenotypes: An IPSCSG Study

Rudi Alberts, PhD, Department of Gastroenterology and Hepatology, University of Groningen and University Medical Centre Groningen, The Netherlands

Amount Awarded: $60,000 over two years.

PSC is a severe and complex disease. Both environmental factors and genetics are involved in its development and course. Genetic studies have identified sixteen genetic loci on multiple chromosomes that are associated with PSC. The main contribution of these studies is increased insight into PSC pathogenesis. However, ever since the first human genome was sequenced in 2003, the clinical world has been waiting for translation of genetic knowledge into personalized care for individual patients. To which extent do genetics drive differences in PSC disease behavior? Do genetic mutations within PSC patients separate patients with a mild disease course from those suffering from severe progressive disease? Do genetic mutations within PSC patients separate patients that do and do not develop cholangiocarcinoma? To address these and related questions, within the International PSC Study Group (IPSCSG) we have performed the largest PSC clinical characterization effort to date, covering over 3000 patients from hospitals in 13 countries. The primary aim of this study is to identify genetic variants driving PSC clinical characteristics. The most important characteristics collected are date of birth and diagnosis, date and cause of death (PSC related, cholangiocarcinoma, hepatocellular carcinoma etc.), dates of liver transplantations and co-occurrence with IBD. Genetic mutations are identified using the Immunochip genotyping platform, interrogating ~200.000 genetic variants. By combining clinical characteristics with genetic variants we can discover genetic loci that are associated with these characteristics. Furthermore, information across all mutations will be combined to build genetic risk scores for these characteristics. These can potentially be used to predict, based on the DNA of the patient, whether he or she is likely to develop one of the aforementioned PSC characteristics or complications.

2015 Update

In the past year we have finished the collection of PSC sub-phenotypes. Also, for each of the 3402 PSC patients, we have coupled the sub-phenotypes to the genetic variants, i.e. genotypes.

We started our analyses with yes/no phenotypes, for example, comparing PSC patients that have developed cholangiocarcinoma with PSC patients that did not. This revealed several suggestive links between genetic variants and those phenotypes. Most interesting links were found by comparing PSC patients with and without Autoimmune Hepatitis.

Next we analyzed several phenotypes that are measured through time. For example, we have data indicating at which date patients were diagnosed with PSC and also, at which date they underwent a liver transplantation. By comparing this data with genetic data, we found a strong link between a genetic variant located on chromosome 6 and transplant-free survival. We are currently finalizing a manuscript reporting this finding.

Until now, no genetic variants are known that are linked to transplant-free survival. Now we have identified a protein that is possibly involved in transplant-free survival. Further research needs to be done to confirm this finding.

2016 Update

Previously, we have collected sub-phenotypes describing PSC disease severity and complications and genetic information for a large cohort 3402 PSC patients. We found a genetic variant on chromosome 6 that is significantly associated with the phenotype liver transplant-free survival. Also we identified the gene RSPO3 as most likely candidate for this association.

In the past year we investigated the gene expression of RSPO3 in disease-relevant cells. We found that in mouse cholangiocytes and cholestatic cholangiocytes indeed RSPO3 is highly expressed. We also found in human hepatic stellate cells, the cell type that is mainly involved in liver fibrosis, expression of this gene.

We have presented our results at two international congresses and are in the process of publishing them.

This project is partially funded by the generous support of Axel and Karen Rasmussen.

Distinguishing primary sclerosing cholangitis from IgG4-associated cholangitis: Specific IgG4 class-switched B-cells as diagnostic tool.

Ulrich Beuers, MD, Department of Gastroenterology and Hepatology and Tygat Institute of Liver and Intestinal Research, Academic Medical Center, University of Amsterdam, The Netherlands.

Amount Awarded: $60,000 over a period of two years

Primary sclerosing cholangitis (PSC) and the more recently defined Immunoglobulin G4-associated cholangitis (IAC) are inflammatory diseases of the bile ducts and the liver of unknown cause which are difficult to distinguish with conventional biochemical and imaging studies. Patients with PSC and IAC are predominantly male, show a cholestatic serum enzyme pattern and similar stenoses and dilatations of the intra- and/or extrahepatic bile ducts. The serum immunoglobulin IgG4 may or may not be elevated both in IAC and PSC. An accurate diagnostic marker is lacking, but urgently needed as long-term course and treatment of PSC and IAC differ markedly. We have recently identified dominant IgG4+ B-cell receptor (BCR) clones in blood and affected tissue of patients with IAC, but not PSC and based on these findings have unravelled “blue collar” work with chronic exposure to environmental toxins such as solvents, industrial and metal dusts, pigments and oils used in the automotive industry as a potential risk factor for IAC, but not PSC. With our actual proposal, we aim to (i) provide a reliable, cost-effective and patient-friendly diagnostic marker to distinguish between PSC and IAC. We also want to provide a deeper molecular understanding of the role of IgG4 in IAC and PSC by (ii) trying to identify antigens responsible for the expansion of recently described dominant IgG4+ B-cell receptor (BCR) clones in IAC in comparison to PSC; (iii) study the role of T-cells by performing T-cell receptor (TCR) sequencing in patients with IAC in comparison to PSC who have previously undergone BCR sequencing; and (iv) further assess risk factors predisposing to IAC in comparison to PSC.

2015 Update

We have recently demonstrated with a novel genetic analytical method, the so-called next-generation sequencing (NGS) technique, with which the genetic information (RNA) for about 10.000 different proteins on the surface of B-lymphocytes can be determined that dominant IgG4+ B-cell receptor (BCR) clones accurately distinguish patients with IAC from those with PSC or cholangiocarcinoma. Based on these findings, we had unraveled “blue collar” work with chronic exposure to environmental toxins such as solvents, industrial and metal dusts, pigments and oils used in the automotive industry as a potential risk factor for IAC, but not PSC. We are meanwhile able to confirm our results in a total of 68 patients with IAC, PSC or carcinoma of the bile ducts or pancreas using this expensive and time-consuming NGS technique. Based on these results, we have now developed a novel, by far more affordable, widely applicable quantitative polymerase chain reaction (qPCR) protocol analyzing IgG4 RNA of B-cells in blood. In the 80 patients tested so far, the diagnostic accuracy of the simple new test was remarkable. Thus, IgG4+ B-cell receptor clones and IgG4 RNA may distinguish PSC (and cholangiocarcinoma) from IAC better than the tests so far available and may become a valuable diagnostic tool in the future. We continue our efforts to further validate the new diagnostic qPCR test in a large prospective study. In addition, we focus on unraveling the proteins against which the IgG4 are directed in IAC and PSC to better understand the differences in the inflammatory processes in these diseases.

2016 Update

With financial support of the PSC partners seeking a cure we recently unraveled that the IgG4-producing B cells in patients with active IgG4-RD of the biliary tract (IAC) or pancreas (autoimmune pancreatitis; AIP) are derived from a limited number of highly expanded IgG4+ B cell receptor (BCR) clones, by applying novel next generation sequencing (NGS) technology3,4. These IgG4+ BCR clones were not found in healthy and diseased controls with PSC and hepatobiliary or pancreatic cancer. These findings indicated that development of an accurate (sensitive and specific) diagnostic marker for IAC was within reach. For comparison, conventional serum IgG4 did not reach an acceptable accuracy in distinguishing IgG4-RD from PSC and hepatobiliary/pancreatic malignancies. Still, NGS technology is work-intensive, expensive and unaffordable for routine clinical use. Based on our findings using NGS technology, we recently developed a widely affordable qPCR test (compared to NGS technology) to use blood IgG4/IgG RNA-ratio as marker for early diagnosis of IAC. We found that blood IgG4/IgG RNA-ratio as determined by a simple qPCR reached high accuracy for delineation from PSC and hepatobiliary and pancreatic malignancies comparable to that of IgG4+BCR clones identified by NGS4.  IgG4/IgG RNA-ratio was also demonstrated to be potentially useful for monitoring of IAC disease activity during treatment . Use of this novel IgG4/IgG RNA-ratio was recommended as diagnostic test for patients evaluated for possible IgG4-related pancreatobiliary disease5.

References

  1. Hubers LM, Maillette de Buy Wenniger LJ, Doorenspleet ME, et al. IgG4-associated cholangitis: a comprehensive review. Clin Rev Allergy Immunol 2015;48:198-206.
  2. Maillette de Buy Wenniger LJ, Culver EL, Beuers U. Exposure to occupational antigens might predispose to IgG4-related disease. Hepatology. 2014;60:1453-4
  3. Maillette de Buy Wenniger LJ, Doorenspleet ME, Klarenbeek PL, et al. Immunoglobulin G4+ clones identified by next-generation sequencing dominate the B cell receptor repertoire in immunoglobulin G4 associated cholangitis. Hepatology 2013;57:2390-8.
  4. Doorenspleet ME, Hubers LM, Culver E, et al. IgG4+ B-cell receptor clones distinguish IgG4-related disease from primary sclerosing cholangitis and biliary/pancreatic malignancies. Hepatology 2016;64:501-7.

Tabibian JH, Lindor KD. Distinguishing IgG4-related disease from its pancreatobiliary mimics: Are we there now? Hepatology 2016;64:340-2.

Read More

Immunoglobulin G41 B-Cell Receptor Clones Distinguish Immunoglobulin G4-Related Disease From Primary Sclerosing Cholangitis and Biliary/ Pancreatic Malignancies

Distinguishing Immunoglobulin G4–Related Disease From Its Pancreatobiliary Mimics: Are We There Now?

This project is partially funded by the generous support of Don and Ricky Safer.

Accelerated Identification of Preclinical Models for Primary Sclerosing Cholangitis (PSC) Using IBM Watson Cognitive Technology

Lisa B. Boyette, MD, PhD, SAVE JON, Inc., Pittsburgh, PA

Amount Awarded: $30,000 over a period of one year

Genetically mutated strains of mice or other small animals sometimes exhibit features of human disease.  These small animal “models” are tremendously useful for studying a disease and testing therapies for that disease.  Finding the right genetic mutation such that the mouse’s disease resembles a specific human disease is usually a matter of chance when the cause of the disease is not understood.  There are currently no good animal models for Primary Sclerosing Cholangitis (PSC), but identifying one or more would open new avenues for understanding the causes of PSC.  We propose to accelerate this process of identifying good animal models for PSC.  Using the cognitively enabled IBM Watson supercomputer, we will search all available published medical literature and animal model databases for small animal models exhibiting disease features of PSC.  We will use this information to formulate a comprehensive list of possible models for PSC from records of thousands of existing animal models currently in use to study other diseases.  We will publish a rank-ordered list of our findings, annotated with all of the information we were able to gather about each model, and make this data easily accessible to the entire PSC research community.  In the future tissues can be obtained from each of those animals to validate them as model organisms for PSC studies in the lab.

Update:

Laboratory animals mimicking human diseases are valuable resources that help us understand diseases and develop cures. However, as we do not have a complete understanding of what causes PSC, an animal model that mimics PSC perfectly has not yet been established through genetic engineering, and such a model has not spontaneously emerged for us to study. The animal model
traditionally used for reference in PSC research is a mouse with a mutation in a gene called MDR2. This mouse has a liver disease that is very similar to the fibrosis (scarring) observed in the bile ducts and livers of PSC patients. However, mice with an MDR2 mutation do not display an increased frequency of bile duct cancer, which does occur in the human PSC population. Furthermore, PSC
affects more men than women and can involve many symptoms outside of the liver, most notably IBD and symptoms that overlap with other autoimmune disorders. Therefore, we performed a large-­scale analysis of all mice with known gene modifications to determine if any other mice have features that mimic multiple aspects of human PSC. From our analysis, we produced a list of gene modifications that are known to affect the liver, digestive system, immune system and tumor development in mice. The features produced by these gene mutations were examined in detail, and the genes were then ranked for their ability to cause
aspects of PSC in mice. However, the mouse symptoms recorded in association with gene changes often varied with the particular genetic background of each mouse and the environmental challenges presented to them. Furthermore, some mice that showed potential mimicking of PSC need to be analyzed in greater detail. Therefore, from our list we have created a database that will be made publically available to the PSC research community. Our database will guide researchers towards potential models of interest for PSC research that should be further examined in the context of
different genetic and environmental conditions. As investigations ensue and more information is gathered, the database will be updated to refine the rankings and provide researchers with a
reference tool detailing more specific mouse models for PSC..

This one year project is funded by the generous support of John and Chris Browner, David and Rosalind Parry.

Aberrant Dendritic cell functions that cause inflammatory bowel disease

Gianna E. Hammer, PhD, Duke University, Immunology Department, Durham, NC

Amount Awarded: $60,000 over a period of two years

Although patients with primary sclerosing cholangitis (PSC) often also have inflammatory bowel disease (IBD), next to nothing is known about the cell types and mechanisms that connect these two diseases. A major block to deciphering these connections is the lack of animal models that develop both PSC and IBD. In IBD pathophysiology, we have identified a key cellular and molecular module in mice that drives disease: dendritic cells that lack the intracellular enzyme A20 cause IBD by aberrantly activating inflammatory immune cells. How inflammatory responses of dendritic cells may cause PSC, and whether dendritic cells in the liver also require A20 to prevent aberrant immune activation, is unknown. The goal of this proposal is to define the role of A20 in dendritic cell subsets of the intestine and liver. Additionally, we will identify PSC-related pathologies in the livers of mice lacking A20 expression specifically in dendritic cells—we propose that these mice may be a novel animal model for the study of both IBD and PSC.

2015 Update

We have found a key pathological cell type that can cause inflammation in both the liver and the intestine: the dendritic cell. Dendritic cells (DCs) are part of the immune system and serve two functions: 1) Sense microbes and 2) Instruct the rest of the immune system to the presence of these microbes. We have been testing these DC functions in the intestine and determining how these functions are related to microbial commensals. We have identified DCs that interact with microbial commensals and determined that DCs that are hyper-active to microbial commensals incorrectly instruct pro-inflammatory immune responses in the intestine. These pro-inflammatory immune responses are largely the result of T cells that secrete dangerous molecules once they encounter a microbial target. We are further testing whether these same mechanisms are operating in the liver and whether T cells that cause inflammation in the intestine are similar to T cells that may cause inflammation in the liver.

2106 Update

To understand the links between gut inflammation and liver inflammation we are studying dendritic cells. Dendritic cells are immune cells that live in both liver and gut. In these tissues dendritic cells interact with bacteria and other immune cells. We study dendritic cells because dendritic cells are like the volume button of the immune system. When dendritic cells have a very high response to gut bacteria, they give out signals to other immune cells. These signals tell other immune cells to make proteins that cause inflammation. These intense immune responses are responsible for inflammation. There are different types of dendritic cells and we found that each has a unique response to gut bacteria. Interestingly, when the response to gut bacteria is very high, each type of dendritic cell sends out a different kind of signal. Each type of signal tells immune cells to produce a different type of inflammatory protein. For example, we found one type of dendritic cell gives the signal to make the inflammatory protein IFN. And a second type of dendritic cell gives the signal to make a totally different inflammatory protein, IL-17. These inflammatory proteins cause gut inflammation.

Once we learned that certain types of dendritic cells were responsible for specific inflammatory proteins, we designed a type of therapy to block gut inflammation. Using mice, we eliminated the specific gut dendritic cell that gives out the signal for the inflammatory protein IL-17. By getting ride of this dendritic cell we successfully reduced the amount of IL-17 in the gut and reduced the level of gut inflammation. Now that we understand how dendritic cells cause gut inflammation, we will determine how these dendritic cells impact liver inflammation. We will also test whether liver dendritic cells behave similar to gut dendritic cells. Once we answer these questions our research could lead to new therapies for PSC.

Publications:

Liang J, Huang H, Benzatti F, Karlsson AB, Zhang JJ, Youssef N, Ma A, Hale LP and Hammer GE. (2016). Inflammatory Th1 and Th17 in the intestine are each driven by functionally specialized dendritic cells with distinct requirements for MyD88. Cell Reports (accepted, in press)

This project is partially funded by the generous support of the Grover Family Foundation and Deborah Wente.

The Role of CD1D In Regulating Inflammation in PSC

Espen Melum, MD, PhD, Norwegian PSC Research Center, Oslo University Hospital, Rikshospitalet, Oslo, Norway

Amount Awarded: $60,000 over a period of two years

Primary sclerosing cholangitis (PSC) is a chronic inflammatory biliary disease. At present little is known about the pathogenesis of PSC. Findings in genetic studies clearly suggest that inflammatory mechanisms are involved. Natural killer T (NKT) cells are activated by lipid antigens, and represent a major lymphocyte population in the liver with potent regulatory properties that are likely to regulate immune driven liver diseases.This project aims for in-depth exploration of the role of NKT cells in the bile ducts and PSC by using human samples and an induced mouse model of cholangitis, resembling PSC. The level of CD1D, the molecule that activates NKT cells will be examined in liver from patients with PSC and compared to controls. We have previously demonstrated that the cells lining the bile ducts (cholangiocytes) can activate NKT cells and now we plan to develop a novel mouse model where we can examine this. This model will increase our understanding of NKT cells in the bile ducts and how their activation is affecting the inflammation. The establishment of a novel induced murine model can also be used to test other interventions and potential treatments in future studies.

2105 Update

During the first year of funding from PSC Partners we have closely examined certain molecules involved in activating an important subset of lymphocytes called NKT cells. In these studies we have demonstrated that these activating molecules are decreased in PSC patients, implying a potential of less ability to activate these regulatory cells.

It is absolutely necessary to have proper animal models to move the field of PSC research further. In an attempt to establish such a model, we have developed a novel surgical technique where we are able to inject substances into the bile ducts of mice under anesthesia. This model can be useful for testing compounds directly injected into the bile ducts of diseased livers and to elicit inflammation in healthy livers.

Our first experiments using this novel model have been to inject irritants that can activate the lymphocyte subsets mentioned in the first paragraph. To aid these studies we have used genetically modified mice that lack these NKT cells and thus been able to demonstrate the activation of these cells in the bile ducts of normal wild type animals.

During the next year we will substantially expand on the murine models and try further to dissect the mechanisms that govern this induced inflammation in the bile ducts. We are extremely grateful for the funding received from PSC Partners Seeking a Cure that has enabled these studies. PSC Partners Seeking a Cure will be acknowledged in all publications based on these results.

2016 Update

As it is absolutely necessary to have proper animal models to move the field of PSC research further, we aimed at establishing a new mouse model to study bile duct inflammation and the role of bile duct cells in disease. During the first year of funding we began the work of developing a novel surgical technique that would allow injection of substances into the bile ducts of mice under anesthesia. This model can be useful for testing compounds directly injected into the bile ducts of diseased livers and to elicit inflammation in healthy livers.

After much work with optimizing the surgical technique we finally succeeded in the establishment of the surgical technique. In the past year we have applied this technique to inject irritants into the biliary tree, which allows us to study the role of the above-mentioned NKT cells and their activating molecule in bile duct inflammation. We have run multiple experiments in normal wild type mice and genetically modified mice that lack these NKT cells. We have now successfully established a bile duct inflammation model that is driven by NKT cells. While normal wild type mice develop disease when injecting an irritant into the bile ducts, the genetically modified animals that lack NKT cells are somewhat protected from disease. Furthermore, we have been able to inhibit development of disease in normal wild type mice by treating them with blocking of the NKT activating molecule before surgery. We are presently working with preparation of manuscripts for both the establishment of the new surgical technique and the bile duct inflammation model.

We are extremely grateful for the funding received from PSC Partners Seeking a Cure that has enabled these studies. PSC Partners Seeking a Cure will be acknowledged in all publications based on these results.

Published results (Note: link for publication included below)

The biliary epithelium presents antigens to and activates natural killer T cells.

Schrumpf E, Tan C, Karlsen TH, Sponheim J, Björkström NK, Sundnes O, Alfsnes K, Kaser A, Jefferson DM, Ueno Y, Eide TJ, Haraldsen G, Zeissig S, Exley MA, Blumberg RS, Melum E. Hepatology, 2015 Oct;62(4):1249-59. doi: 10.1002/hep.27840.

Natural Killer T cells aggravate inflammation in a novel induced murine model of cholangitis. Berntsen NL, Fosby B, Tan C, Schrumpf E, Bjornetro T, Foss A, Line PD, Karlsen TH, Blumberg RS, Melum E. AASLD 2015 in San Francisco.

This project is partially funded by the generous support of Don and Ricky Safer.

Role of Natural Killer Cells in the Pathogenesis of Primary Sclerosing Cholangitis

Guoxiang Yang, MD, PhD, Department of Internal Medicine, Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, CA

Amount Awarded: $60,000 over a period of two years

Primary sclerosing cholangitis (PSC) is an autoimmune disease that destroys the bile ducts in the liver and can lead to liver failure. Most people with PSC also have ulcerative colitis or Crohn’s disease, two type of inflammation that affect the large intestine. Current evidence suggests that the immune cells that become active in the intestine lead to the inflammation and damage
caused by PSC in the liver. One type of immune cells which might cause this damage are called natural killer (NK) cells. These cells have been identified as central to several other autoimmune diseases and recent genetic data implicate them in PSC as well. Our pilot data has shown that NK cells are activated in the blood of PSC patients. We believe that these NK cells originate in the intestine and subsequently migrate to the liver where they cause PSC. Our project will determine if the NK cells of PSC reflect a unique type of immune cells and will provide evidence of the potential role of these cells in the targeted destruction of bile ducts. Altogether, this application will provide important insights into the link between PSC and IBD. We believe that these studies have the potential to identify new therapeutic approaches to the treatment of PSC.

2015 Update

Primary sclerosing cholangitis (PSC) is a chronic autoimmune disorder targeted to intra and extra-hepatic bile ducts. Although cellular and genetic studies have shown that nature killer (NK) cells are involved in the pathogenesis of PSC, the immunological mechanism is unclear. Herein, we dissected the circulating NK cells and compared the phenotypic and functional characteristics of different subsets of NK cells from patients with PSC to that from healthy controls. We utilized special technique, called single cell staining, to evaluate the specific molecules expressed on the cell surface. We found that the number of NK cells is decreased in peripheral blood in patients with PSC. These cells also exhibited immature phenotype and were more activated. Furthermore, the NK cells from patients with PSC have a great capacity to kill the target cells. Collectively, our data demonstrated that in patients with PSC, deficiency in maturation with aberrant enhanced cytotoxicity in the NK subset is intriguing and significant. This distinct population of NK cells could be functionally involved in the pathogenesis of PSC. Of particular importance in our next step of study is to determine 1) if these aberrant NK cells are present in the liver; and 2) whether these NK cells have biliary epithelial cell cytotoxic activity.

This project is partially funded by the generous support of Mohammed Aslam and Fred Sabernick.

Awarded in 2013

In 2013, PSC Partners funded seven PSC research studies.  The recipients of the awards are Dr. Eva Ellinghaus, Institute of Clinical Molecular Biology, Christian-Albrechts-Universtiy of Kiel, Germany; Romina Fiorotto, PhD, Department of Internal Medicine, Section of Digestive Diseases, Yale University, New Haven, CT; Stefano Fiorucci MD, Department of Experimental and Clinical Medicine, University of Perugia, Italy; Heather Francis, PhD, Assistant Professor, Texas A&M Health Sciences Center, Temple, TX; Nicholas F. LaRusso, MD, Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic, Rochester, MN; Evaggelia Liaskou, PhD, Post-Doctoral-Research-Fellow, NIHR Biomedical Research Unit in Liver Disease & Centre for Liver Research, Institute of Biomedical Research School of Immunity and Infection, University of Birmingham, England; Alexander G. Miethke MD, Assistant Professor of Pediatrics, Pediatric Gastroenterology, Hepatology, and Nutrition, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH.

Whole exomes sequencing of primary sclerosing cholangitis patients with severe disease


Eva Ellinghaus, MD and Andre Franke, MD, Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Germany.
Amount Awarded= $60,000 over two years

Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease of the intra- and extra hepatic bile ducts. There is scarce knowledge on etiology and pathogenesis of PSC, and due to lack of effective therapy, PSC has become one of the leading indications for liver transplantation in Northern Europe and the US. The strong genetic component to PSC risk is highlighted by an approximately 9-39 fold increase in sibling risk relative to the general population and recent studies have identified 16 susceptibility regions in the human genome that increase the risk for developing PSC. These, however, explain only 7.3% of variance in PSC liability. Therefore, to identify further sources of heritability, e.g. rare susceptibility variants with potentially high penetrance, systematic resequencing studies need to be performed.

By using a next-generation sequencing-based approach, it is planned to sequence the exomes, i.e. the protein-coding part of the human genome, of 48 unrelated PSC patients with severe disease to dissect the contribution of rare and low frequency coding variants to the complex phenotype of PSC. Newly identified mutations with potentially damaging effect will be validated and followed up in a large case-control sample. Functional analysis of these mutations is aimed for and the ultimate goal is to identify potential targets for therapeutic intervention.

Progress Update: Read a November 2014 progress update report on this grant.

Read the final report for this grant.

Role of epithelial toll like receptor dependent innate immune responses in the pathogenesis and treatment of primary sclerosing cholangitis.

Romina Fiorotto, PhD, Mario Strazzabosco, MD, PhD, Department of Internal Medicine, Section of Digestive Diseases, Yale University and Tom H. Karlsen, MD, PhD, Norwegian PSC Research Center, Oslo, Norway.
Amount Awarded= $60,000 over two years

The etiology and pathophysiology of PSC remain still unclear. Two hypotheses have been proposed. The association with inflammatory bowel disease (IBD) suggests an involvement of innate immune mechanisms as a possible trigger. On the other hand, the retention of toxic bile acids able to damage the biliary epithelium is proposed as an alternative hypothesis (‘toxic bile’ hypothesis). However a common pathogenetic mechanism that explains the progression of the disease is still lacking. PSC has several common features with cystic fibrosis (CF), a genetic disease caused by mutation in CFTR, a chloride channel involved in biliary secretory function. Using a mouse model of CF we have recently described that lack of CFTR alters the innate immune responses in the biliary epithelium to endotoxins. In addition, we found that experimental bile acid toxicity causes more severe liver damage in CF mice and induces the expression of High Mobility Group Box-1 (HMGB-1), a molecule known to activate TLRs 4 and 2 mediated innate immune responses. Furthermore, we have preliminary evidence that cholangiocytes isolated from PSC patients present enhanced innate immune responsiveness to endotoxins.

Based on our recent findings, we propose that different types of biliary damage may be responsible for aberrant activation of the innate immunity in CF as well as in PSC and that activation of innate immune pathways represent a common event in the pathogenesis of sclerosing cholangitis. To pursue our hypothesis, we aim to study in vivo the effect of bacterial components and toxic bile acids on the innate immune response of the biliary epithelium in the CF mouse model. We expect to find the release of specific molecules that trigger innate immune responses after liver injury. We will then use these molecules to challenge in vitro CFTR-defective mouse cholangiocytes and human cholangiocytes isolated from PSC patients and show the activation of specific immune pathways. If our hypothesis is correct, it would also suggest that targeting the biliary innate immunity responses would represent the correct approach to treat sclerosing cholangitis. Therefore, in line with the recent reported anti-inflammatory and immune modulator role of vitamin D nuclear receptor (VDR) we will then test the effect of vitamin D treatment as a novel therapeutic approach to modulate the biliary epithelium innate immunity in vivo in the CF mouse model and in vitro in CFTR-defective mouse cholangiocytes and in human cholangiocytes isolated from PSC patients. These studies will have a strong translational potential for the treatment of PSC.

The first year of this project was funded by a generous donation from Abe and Rachel Gomel.

Read the final report for this Grant including the article published in the AASLD Journal of Hepatology.

Bile acid activated receptors TGR5 and FXR as therapeutic targets for the treatment of PSC

Stefano Fiorucci, MD and Barbara Renga, PhD, Department of Experimental and Clinical Medicine, University of Perugia, Italy.
Amount Awarded= $60,000 over two years

Primary sclerosing cholangitis (PSC) is a rare chronic cholestatic disorder of the liver and bile ducts that is characterized by fibrosing inflammation of the intra- and/or extrahepatic biliary tree generally leading to progressive bile duct obstruction, fibrosis, cirrhosis and end-stage liver disease. The pathogenesis of PSC remains enigmatic, making the development of targeted therapeutic strategies difficult. Primary sclerosing cholangitis, like other chronic cholestatic liver diseases, is characterized by hepatic retention of potentially toxic substances normally excreted into bile, in particular hydrophobic bile acids, as a consequence of impaired hepatobiliary secretion and/or obstruction of bile flow. Elevated levels of bile acids can lead to hepatocyte injury, liver failure and the need for liver transplantation.  Bile acids are endogenous ligands for the nuclear receptor farnesoid X Receptor (FXR) and the G-protein coupled receptor TGR5. FXR agonists are not the first candidate for long-term treatment of PSC. On the contrary, it has been recently demonstrated that FXR antagonism could be useful in the treatment of liver cholestasis and that theonellasterol, a natural highly selective FXR antagonist, exerts beneficial effects in the treatment of obstructive cholestasis. TGR5 has been recently identified as an important candidate gene for several inflammatory and metabolic conditions. Indeed, mutations of TGR5 gene were detected in both ulcerative colitis (UC) and PSC. The specific aims of this study are to investigate the effect of an FXR antagonist, such as the marine steroid theonellasterol, alone or in combination with UDCA in animal models of PSC and to evaluate the role of TGR5 in the pathogenesis of PSC and the effect of TGR5 agonists in the treatment of PSC.

This project will be entirely funded by generous donations from David and Ros Parry and ITW.

Progress Update: Read a November 2014 progress update report on this grant.

Bile acid-regulation of mast cells in models of primary sclerosing cholangitis and cholangiocarcinoma

Heather Francis, PhD, Assistant Professor and Sharon DeMorrow, PhD, Associate Professor, Texas A&M Health Science Center.
Amount Awarded= $60,000 over two years

Primary Sclerosing Cholangitis and the primary liver cancer, cholangiocarcinoma, are devastating liver diseases that target cells within the liver called cholangiocytes.  These diseases have limited treatment options.  Patients that present with Primary Sclerosing Cholangitis have a higher incidence of developing cholangiocarcinoma. When cholangiocytes (that line bile ducts where bile flows out of the body) become damaged and ducts become blocked, cholangiocytes will increase in number and this disrupts the normal state of the liver and bile flow. Bile acids are synthesized by the liver to aide in the digestion of foods and the secretion of bile. Patients with liver disease are sometimes treated with bile acid therapy to attempt to improve liver function.  Ursodeoxycholate is a secondary bile acid that is used in patient therapy for Primary Sclerosing Cholangitis and has been found to have beneficial effects in patients suffering from these diseases.  Besides cholangiocytes, mast cells (inflammatory cells that release histamine in the body) are found in the liver and increase in number during liver disease.  When mast cells are treated with bile acids there is a release or blockage of histamine release (depending on the type of bile acid). Our proposal will aim to determine if mast cells and cholangiocytes interact with each other during disease progression and if bile acid treatment can alter their interactions. We will use animal models of both Primary Sclerosing Cholangitis and cholangiocarcinoma as well as cell culture lines to evaluate our specific aims. We believe that by altering mast cell histamine release, cholangiocytes will be repaired and disease progression may be halted.

The first year of this project will be funded by a generous donation from Ken and Patty Shepherd in addition to the proceeds from their annual fundraiser.

Progress Update: Read a November 2014 progress update report on this grant.

Progress Update: December 2015

To date, we have found that mast cells infiltrate the liver during PSC and cholangiocarcinoma progression. Once these cells migrate to the liver they release numerous mediators that can negatively impact a patient’s prognosis. One of the main factors released is histamine that can contribute to the progression of liver injury or tumor growth.  Since we have found a large number of mast cells in the liver following injury, we recently developed a technique to isolate or extract these cells from rodent liver giving us a tool to better examine their effects on PSC and cholangiocarcinoma models. Further, following treatment with cromolyn sodium, a compound that blocks the release of histamine from mast cells, we have demonstrated that there is a decrease in liver fibrosis (which is a consequence of diseases like PSC) and tumor growth.  We have found that treatment with ursodeoxycholate decreases the release of histamine from mast cells, which may also be an important finding in the treatment fibrosis or cholangiocarcinoma.  Our results demonstrate that targeting mast cells may be a potential therapy for patients suffering from PSC and cholangiocarcinoma.  Using human patient samples we have demonstrated that in PSC patients (advanced and late stages) there is an infiltration of mast cells compared to normal liver samples and histamine levels increase significantly in these patients.

Progress Update: May 2016

Read the final report and see the publications generated as a result of this grant.


The cholangiocyte senescence associated secretory phenotype as a therapeutic target in primary sclerosing cholangitis.

Nicholas F. LaRusso, MD, Steven P. O’Hara, PhD, and James H. Tabibian, MD, Mayo Clinic Center for Cell Signaling in Gastroenterology.
Amount Awarded= $30,000 for one year.  This is a follow up from previous funding

Primary sclerosing cholangitis (PSC) is a multifactorial disease believed to have genetic, immunologic, microbial, and other environmental components.  Emerging evidence suggests that cholangiocytes, i.e. the cells that line the bile ducts, may not only be cellular targets of PSC, but participate in driving the disease.  In this regard, our recent data suggest that a subset of cultured (i.e. in vitro) cholangiocytes, in response to certain injurious stimuli, undergo transition to a cellular state in which they are no longer able to replicate but remain capable of secreting pro-inflammatory and pro-fibrotic mediators—and do so in excess amounts.  We believe, and our data support, that this state is representative of a senescence-associated secretory phenotype (SASP).  SASP cholangiocytes, as newly presented by us at the 2013 AASLD Presidential Plenary Session, “Advances in Hepatology”, are not only induced experimentally, but are also present in PSC liver specimens as well as an animal model of PSC.  Therefore, based on our ongoing work in this area, we propose that chronic exposure to injurious, SASP-derived molecules promotes biliary injury, thereby contributing to the development and progression of PSC.  In this proposal, we will examine the mechanisms, consequences and pathologic outcomes of inhibiting cholangiocyte SASP through different techniques in both cholangiocyte culture and an animal model of PSC.  We believe that in doing so, we may identify novel therapies for further study, with the hope that they will ultimately be sufficiently promising for clinical trials in patients suffering from this disorder.

Progress Update: Read a July 2014 progress update report on this grant.

Linking gene susceptibility and environmental factors to biliary damage in primary sclerosing cholangitis: the CD28/vitamin D axis

Evaggelia Liaskou, PhD, Post-Doctoral Research Fellow and Gideon M. Hirschfield, NIHR Biomedical Research Unit in Liver Disease & Centre for Liver Research. Institute of Biomedical Research School of Immunity and Infection, University of Birmingham, England.
Amount Awarded= $60,000 over two years

Primary sclerosing cholangitis (PSC) is a chronic autoimmune liver disease that is seen across all ages. Over time damage to the bile ducts can cause bile duct obstruction, secondary liver scarring and also a risk of cancer. A combination of environmental and genetic factors are important in why someone gets PSC, therefore understanding the interaction between these two factors will help us understand better the causes of disease, something critical to helping develop new drug treatments.

Many genes and environmental factors have now been linked to PSC. We are interested in vitamin D levels in PSC, because low levels are associated with other autoimmune diseases. We are also interested in one particular gene associated with PSC, called CD28, because this gene is very important in controlling how cells respond to injury. Some white blood cells that lose the ability to make CD28 protein are more inflammatory and such cells are more frequently found in autoimmune diseases.

In our project we are going to study how in PSC the cells that lose CD28 work, whether they cause bile duct inflammation, and if there is an association between a person’s gene signature, and CD28 function. We’ll also look to see if vitamin D is important in this particular pathway, particularly as we know if it is possible to supplement vitamin D in patients.

Work to Date

Primary sclerosing cholangitis (PSC) is a devastating and progressive disorder in which persistent inflammation of the bile ducts (the vessels that collect the bile made by hepatocytes and drain into the gall bladder for storage) results in scarring with blockage of the bile flow and subsequent risk of liver failure and/or bile duct cancer. PSC is considered an autoimmune disease where the patient’s own immune cells are attacking parts of the body. Currently, patients with PSC have no effective medical treatment and frequently need liver transplantation, with the chances of getting the disease again in their new liver being quite high. A combination of environmental and genetic factors are important in why someone gets PSC, therefore understanding the interaction between these two factors will help us understand better the causes of disease, something critical to helping develop new drug treatments. To achieve this patient support in funding our research has been very helpful.

Many genes and environmental factors have been linked to PSC. In our study we were interested in one particular gene called CD28, because this gene is very important in controlling how cells respond to injury. Some white blood cells that lose the ability to make CD28 protein are more inflammatory and such cells are more frequently found in autoimmune diseases. Thus we studied how in PSC the cells that lose CD28 work, whether they cause bile duct inflammation and whether the environmental factor vitamin D is important in this particular pathway.

Our data have shown that a significant proportion of white blood cells, called CD4 and CD8 T cells, found in the liver of PSC patients, have lost the expression of CD28 protein. We found that these CD28 null T cells are highly active cells that express molecules on their surface that can lead them around bile ducts. Moreover, we found that these cells are able to activate and kill the bile duct cells. In the liver tissue of PSC patients we detected high levels of TNFα, and in the laboratory we could show that this molecule could reduce the expression of CD28 by T cells, an effect that was prevented by the administration of vitamin D. We have now extended our study to investigate whether there is an association between a person’s gene signature and CD28 function using samples from healthy volunteers.

Regulation of hepatic lymphocyte responses in pediatric sclerosing cholangitis

Alexander G. Miethke, MD, Assistant Professor of Pediatrics, Pediatric Gastroenterology, Hepatology, and Nutrition, Cincinnati Children’s Hospital Medical Center.
Amount Awarded= $60,000 over two years

It is currently unknown whether PSC in children is different from PSC in adults. Additionally, mechanisms that drive initiation and disease progression in pediatric PSC are not well described. In a mouse model of sclerosing cholangitis we found that T- and NK-lymphocytes infiltrated the liver during the early stages of disease. The surge of these lymphocytes which are capable of injuring bile duct epithelial cells was accompanied by an influx of regulatory T cells. Regulatory T cells represent a small proportion of T helper lymphocytes and are critical for constraining immune responses and preventing autoimmune disorders. Therefore, regulatory T cells seem to be an attractive cellular target for immunotherapy. Here, we propose experiments that manipulate number and activation of regulatory T cells in mice during the early stage of sclerosing cholangitis to better understand how these cells interact with other immune cells in the liver and whether they suppress immune-mediated bile duct injury.  In complementary studies on tissue samples from children affected by PSC we will examine which types of cells important for control of immune activation are present in the liver at the time of diagnosis. Collectively, this data may provide novel insights into mechanisms of hepatic immune activation in sclerosing cholangitis which might lead to new avenues of pharmacotherapy in pediatric PSC.

A significant portion of this project is funded by generous donations from the John and Chris Browner Family.

Progress Updates:

Read the November 2014 progress update report on this grant.

Read the January 2016 progress update report on this grant.  Also read the article Dr. Miethke et. al. published in the AASLD Hepatology Journal about this grant.

Awarded in 2012

In 2012, PSC Partners has funded three PSC research studies. The recipients of the awards include Tim O. Lankisch, MD, Associate Professor of Medicine, at Hannover Medical School in Hannover Germany; Patrick S.C. Leung, PhD, Adjunct Professor of Immunology at the University of California Davis School of Medicine; and Mark S. Silverberg, MD, PhD, Associate Professor at the University of Toronto, Canada.


A Combined Bile and Urine ProtemicTest for the Detection of Cholangiocarcinoma in Patients with Primary Sclerosing Cholangitis
Dr. Tim O. Lankisch, MD,Associate Professor of Medicine, Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hannover, Germany; Dr. Jochen Metzger;Professor Michael P. Manns and Professor Harald Mischak. Amount awarded=$60,000 over two years.

The detection of cholangiocarcinoma (CC) remains a diagnostic challenge particularly in patients suffering from primary sclerosing cholangitis (PSC) who are known to develop CC in approximately 15% of cases. Therefore, the aim of scientific contributions must be directed to early diagnosis of CC with high accuracy. Two case/control studies performed by our group, the one using bile, and the other urine as sample matrix suggested that proteomic analysis is a feasible method to achieve this aim since this has led to peptide multi-marker models with classification accuracies above 80 %. PSC Partners has generously provided us with the resources required to analyze additional peptide marker candidates in bile and urine. This helps us to select those peptides which upon inclusion into our established bile and urine peptide marker sets will further improve classification performance. Particular emphasis will be placed on enhanced sensitivity of CC diagnosis since this will allow the combination of bile and urine proteomic analysis to a unique classification scheme. The later will include both local and systemic changes of CC development and progression into the diagnostic decision of CC during surveillance of PSC patients.

Read the final report for this grant.


Metagenomic Analysis of Bile Microbial Diversity in Primary Sclerosing Cholangitis

Dr. Patrick S.C. Leung, PhD, Adjunct Professor of Immunology, Division of Rheumatology/Allergy, University of California Davis School of Medicine; Jonathan Eisen, PhD and Hoi Shan Kwan, PhD, The Chinese University of Hong Kong. Amount awarded=$60,000 over two years.

The frequent association of primary sclerosing cholangitis (PSC) and inflammatory bowel diseases strongly implicates that translocation (movement) of bacteria/bacterial antigens into the liver can trigger immunological responses in the biliary tract. Such immunological responses that arise from cross-recognition between microbial antigens and self might lead to chronic liver disorders in PSC. We believe evidence of such microbial translocation could be found in the bile from patients with PSC. This study is directed to define the bacterial populations in bile samples obtained from patients with PSC and controls. We will use the state of the art “in low cost high throughput ultra sequencing” (next generation of gene sequencing) to determine the nucleotide sequence of bacterial ribosomal RNA gene in bile samples. Sequences will then be analyzed against DNA data bank to find out what the candidate microorganisms are and how they are related to the gut microbes in these samples. Data obtained could shed light on future work in defining the microorganisms responsible for biliary pathology (behavior) in PSC.

Read the final report for this grant.

Characterization of the Intestinal Microbiome in UC Patients With and Without PSC

Dr. Mark S. Silverberg, MD, PhD, Associate Professor, University of Toronto, Canada; Dr. Gert Van Assche and Dr. David Kevans. Amount awarded=$10,000.

The Inflammatory Bowel Diseases (IBD), Ulcerative Colitis (UC) and Crohn’s Disease (CD) affect about 0.5% of North Americans. UC involves only the large bowel while CD may involve any part of the gastrointestinal tract. Primary Sclerosing Cholangitis (PSC) is a liver condition that affects approximately 2-5% of patients with IBD. Patients with IBD affecting their colon are at increased risk of developing colon cancer (CRC), a risk which is even further elevated in patients with colonic IBD and PSC. Why patients with IBD involving the colon are at increased risk of colorectal cancer and why this risk is even further elevated in patients with concurrent PSC is not known. Additionally, the causes of PSC are unknown and there are few effective therapies. Eventually, individuals affected by PSC may require liver transplantation.

The human intestine contains huge numbers of bacteria and it has been shown that these bacteria may trigger UC and CD. Emerging evidence has also suggested that bacteria may play a role in determining disease behaviour and cancer development. It is speculated that the particular composition of the bacteria in the large intestine may be an important factor causing PSC. New techniques now allow the characterisation of intestinal bacteria using tissue and stool samples. The aim of this study is to assess the amount and type of intestinal bacteria in UC patients with and without PSC to evaluate whether there are differences between these groups which may explain their contrasting disease behaviour. We will also assess whether the composition of intestinal bacteria within these groups is influenced by genetic factors and immune system responses. Our findings may provide insights into the processes underlying disease behavior, cancer development and PSC evolution in UC and potentially lead to new diagnostic and treatment strategies.

Awarded in 2011

The recipients of the 2011 awards include Geoff Baldwin, PhD, Imperial College, London, UK; Nicholas F. La Russo, MD, The Charles H. Weinman Professor of Medicine at the Mayo Clinic in Rochester, MN; and Rinse W. Weersma, MD, PhD, Associate Professor, The University of Groningen, The Netherlands.

*A Nano-Device for the Early Stage Detection of Cholangiocarcinoma
Dr Geoff Baldwin, Reader in Biochemistry, Imperial College London; Professor Richard Kitney; Professor Paul Freemont and Mr. James Field. Amount awarded= $60,000 over two years.

*** Final Lay Report, September 2015 ***

As many PSC sufferers will be aware, cholangiocarcinoma (CCA) is a bile duct cancer and PSC predisposes these individuals to developing this cancer so that it may occur in up to 40% of sufferers. Of great concern is that it is ultimately a leading cause of death for PSC patients. If identified at an early stage, CCA can be treated by resection of the liver. Unfortunately for individuals with PSC, the inadequacy of current screening technologies means that CCA is frequently diagnosed at a late stage when palliative care is the only remaining option.

We obtained funding from PSC Partners to try and change this situation. Our approach has been to develop protein nanocages as a platform for early stage diagnosis of CCA. Protein nanocages (PNs) are naturally occurring spherical structures with large internal cavities. We have developed methods to fluorescently label these PNs so that they can be seen with high sensitivity. In addition we have conjugated them to antibodies. Since antibodies are known that target specific cancer markers on cells, this enables the specific targeting of the PNs to cancer cells. We have shown that the fluorescent PNs can thus be targeted to CCA cells as well as other cancer cell types.

In principle these results demonstrate that PNs can be used as a platform for diagnosis of cancer. However, there is still a long way to go before we can use this in the clinic. We are really focused on keeping the target of clinical application in our sights and so we are now working with clinicians at Hammersmith hospital in London to establish whether we can target cancer in liver tissue from patients.

We are continuing to work with PNs to develop them for diagnostic and therapeutic applications by simultaneously delivering drugs within the cage. Through this we now have interest from pharmaceutical companies and we look forward to exploring the exciting opportunities for protein nanocages.

*Potential Role of Cholangiocyte Senescence in PSC.
Nicholas F. LaRusso, MD, Mayo Clinic Center for Cell Signaling in Gastroenterology, Mayo Clinic. Amount awarded= $60,000 over two years.

Primary sclerosing cholangitis (PSC) is a multifactorial disease with genetic, microbial, and environmental components. Emerging evidence suggests that cholangiocytes, i.e. the cells of the bile ducts, may not only be affected in PSC, but may actually participate in driving disease progression. Our recent data suggest that cholangiocytes, in response to biologically-relevant injurious stimuli, transition from a proliferative to a senescent phenotype, a metabolically active cellular state in which the cell is no longer capable of cell division. Furthermore, these cells secrete excess amounts of inflammatory mediators. Based on our recent work, we propose that chronic exposure to injurious molecules promotes cholangiocyte senescence and secretion of inflammatory molecules, thereby contributing to the development and progression of PSC. The proposed experiments will establish cholangiocyte senescence as a fundamental cholangiocyte response to persistent injury, address the mechanisms by which relevant injurious stimuli induce cellular senescence, and interrogate whether PSC-associated senescent cells are mediators of disease. This is a novel approach to understanding the development and progression of PSC that may have important implications for understanding disease initiation/progression and provide insights for the development of novel therapies.

*The Exome in PSC
Rinse K. Weersma MD, PhD, Associate Professor, Department of Gastroenterology and Hepatology, University of Groningen and University Medical Centre Groningen, The Netherlands; Prof. Dr. rer. nat. Andre Franke, Institute of Clinical Molecular Biology; Christian-Albrechts-University of Kiel, Universitätsklinikum Schleswig Holstein, Campus Kiel Schittenhelmstr. Amount awarded=$60,000 over two years
.

PSC is a complex disease, with both environmental and genetic factors involved in its development and disease course. It is thought that changes in multiple genes in the human DNA explain part of the etiology of the disease. In recent years it became possible to screen the human genome by using 100,000s or even millions of markers spread around the genome. Several regions on the human genome have now been identified that contain genes that are associated to disease. Since PSC is a rare disease and large numbers of patients are required, this work has been performed by multiple centers throughout the world that have collaborated. It is expected that additional genetic regions will be identified in the near future

By using these large numbers of genetic markers, we now know which broad regions on the human genome are associated with the disease, but we do not know which specific genetic variants within these regions are causing protein changes that lead to disease. Most of the associated variants are not causal, but merely markers for other functionally important, causative variants. Variants that reside in the so-called exons of the genes have direct implication in protein function and are therefore very interesting. Part of the heritability is thought to reside in these rare exomic variants with greater effect-sizes. Therefore, the primary aim of the study is the identification and confirmation of rare exomic variants involved in PSC pathogenesis.

This will be done by using a custom-made exome genotyping array including ≈250.000 variants, to genotype a cohort of 1000 PSC patients and 6000 healthy controls. A second cohort of 1000 cases and 1000 healthy controls is available for replication of observed signals. Identified variants will give important insights in disease pathogenesis. The variants on the exome array will have direct functional implications and will therefore enable additional functional studies and hopefully targets for novel therapeutic interventions. In addition we might identify mutations with predictive value for disease occurrence or disease behavior.

Progress Update: Read a September 2014 progress update report on this grant.

Awarded in 2010

In 2010, the Scientific/Medical Advisory Committee selected five proposals for two years of funding:

* Pathogenesis of PSC: Role of TGR5 in the regulation of the innate immune response in the biliary epithelium. Mario Strazzabosco, M.D., Ph.D, Department of Internal Medicine Section of Digestive Diseases, Yale University, 333 Cedar Street-1080 LMP, P.O. Box 208019, New Haven, CT 06520-8019, and Michael Trauner, M.D., Ph.D, Department of Internal Medicine III, Divison of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. Amount awarded = $40,000 over years.

* Epigenetics associated with primary sclerosing cholangitis in monozygotic twins discordant for the disease. Carlo Selmi, MD, PhD, Assistant Professor of Internal Medicine, University of Milan, Physician Scientist, IRCCS Istituto Clinico Humanitas, Rozzano, Milan, Assistant Professor of Medicine, University of California, Davis, Division of Rheumatology, Allergy, and Clinical Immunology, GBSF suite 6515, 451 E Healthy Sciences Drive, Davis, CA 95616. Amount awarded = $40,000 over 2 years.

* Identification of genetic profiles unique to PSC-IBD. Judy Cho, M.D., Associate Professor of Medicine and Genetics, Section of Digestive Diseases, Director, Inflammatory Bowel Disease Center, Yale University, Internal Medicine, 333 Cedar Street, Room LMP-1072, P.O. Box 208056, New Haven, CT 06520-8056. Amount awarded = $40,000 over 2 years.

* Combination treatment with ursodeoxycholic acid and all-trans retinoic acid for primary sclerosing cholangitis (PSC). Shi-Ying Cai, Ph.D., Research Scientist, Section of Digestive Diseases, Department of Internal Medicine, Yale Liver Center, Yale University School of Medicine, 1080 LMP, 333 Cedar Street, New Haven, CT 06520, and James L. Boyer, M.D., Ensign Professor of Medicine, Section of Digestive Diseases, Department of Internal Medicine, Yale Liver Center, Yale University School of Medicine, 1080 LMP, 333 Cedar Street, New Haven, CT 06520. $37,000 over 2 years.

* Establishing the role and molecular mechanisms for pregnane X receptor in progressive sclerosing cholangitis. Sridhar Mani, M.D., Professor, Medicine, Oncology and Genetics, Miriam Mandel Faculty Scholar in Cancer Research, Albert Einstein College of Medicine, 1300 Morris Park Ave, Chanin 302D-1, Bronx, NY 10461. $40,000 over 2 years.

Central themes of the research projects funded in this round, are: genetics and “epigenetics” of PSC, and the use of mouse models of sclerosing cholangitis to probe the pathogenesis mechanisms and accelerate development of novel therapies.

The following are the Project Summary and Specific Aims sections of the funded proposals. Each Project Summary/Specific Aims description of the project (provided by the investigators) is followed by a brief “Interpretation for the layperson” (prepared by David Rhodes). David Rhodes accepts full responsibility for any errors/omissions that may occur in these “layperson” interpretations.

Pathogenesis of PSC: Role of TGR5 in the regulation of the innate immune response in the biliary epithelium.

Mario Strazzabosco, M.D., Ph.D, Department of Internal Medicine Section of Digestive Diseases, Yale University, 333 Cedar Street-1080 LMP, P.O. Box 208019, New Haven, CT 06520-8019, and Michael Trauner, M.D., Ph.D, Department of Internal Medicine III, Divison of Gastroenterology and Hepatology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. Amount awarded = $40,000 over 2 years.

Summary

The etiology and pathophysiology of PSC remain unclear. The strong association with IBD suggests a dysregulation of the innate immunity system and among the different hypothesis, an increased response to bacterial products released by a ”leaky gut” has been suggested. This hypothesis has not been adequately tested because of the lack of adequate animal models. PSC has several features in common with Cystic Fibrosis, an autosomic recessive disease caused by mutation in CFTR, a cAMP-stimulated chloride channel that is involved in the secretory function of the biliary epithelium. We have recently found that CFTR deficiency alters the innate immunity of the biliary epithelium and generates a strong TLR4-mediated inflammatory response when the epithelium is exposed to endotoxins. Recent data suggest that TGR5, a Gprotein-coupled receptor for bile acids, that increases cellular cAMP, co-localizes with CFTR and regulates CFTR targeting and function in response to bile acids. The recent finding that the TGR5 gene is a likely disease gene in PSC let us to hypothesize that, similarly to CFTR, TGR5 may be a regulator of TLR4-mediated innate immunity and that a defective function of TGR5 may lead to an excessive inflammatory response to LPS. In this project, we plan to study the liver inflammatory response to DSS-colitis in TGR5-knockout mice, the effects of LPS on cytokine secretion in cultured TGR5-KO cholangiocytes, and the role of TGR5 on the regulation of the TLR4 pathway. These studies will eventually provide a strong rationale for the development of new therapies.

Specific Aims

Sclerosing cholangitis is a spectrum of progressive cholestatic liver diseases characterized by obliterative fibrosis and inflammation of the intrahepatic and/or extrahepatic biliary system. Primary Sclerosing Cholangitis (PSC) is associated with inflammatory Bowel Diseases (IBD), but while IBD is present in 75-80% of PSC cases, only 5-8 % of patients with IBD develop PSC. The etiology and pathophysiology of PSC, as well as the nature of the relationship with IBD remain unclear. Besides the “autoimmune” and the “toxic bile” hypothesis, the “leaky gut” hypothesis suggests that PSC is caused, in susceptible individuals, by exposure of the biliary tree to bacterial endotoxins. The lack of experimental models has hampered progresses in the study of PSC pathogenesis. Recent data generated by our lab indicate that cystic fibrosis may represent an interesting model disease. Cystic Fibrosis (CF) is a genetic disorder of secretory epithelia, caused by the defective function of a Cl- channel essential for bile secretion, called CFTR.. Several patients with CF present a cholangiopathy that shares many similarities with PSC. Both conditions manifest as a slowly progressive fibrosing cholangitis, affecting any tract of the biliary tree, with similar histologic and radiographic findings and a common evolution in biliary cirrhosis. Similar to PSC, that affects only a minority of IBD patients, liver disease affects a minority of CF patients. CFTR-knockout (CTR-KO) mice do not show spontaneous liver pathology, but develop a severe cholangitis after induction of colitis with dextran sodium sulfate (DSS). DSS-treatment had no effects on wildtype animals, suggesting that development of biliary inflammation and liver disease required the interaction between genetic predisposition and acquired factors. We have shown that, independently from the secretory defect, the biliary tree of CF-KO mice is more susceptible to endotoxins that enter the portal circulation because of the increased intestinal permeability. In fact, CFTR-defective cholangiocytes show an altered posttranslational regulation of TLR4 activity, and exhibit a stronger Src-dependent TLR4/NF-kB-mediated inflammatory response to an endotoxin challenge. Thus, CF-cholangiopathy, rather than being the consequence of ductal cholestasis, results from altered innate immune responses of CFTR-KO cholangiocytes. Similar mechanisms may apply to the primary form of sclerosing cholangitis. Recent genome wide association data provided circumstantial evidence that the G-protein-coupled bile acid receptor-1 (gpr1 or TGR5), is a potential disease gene in PSC. TGR5 is a bile acid receptor that generates cAMP upon binding of bile acids. TGR5 was shown to colocalize with CFTR and to be able to activate and stimulate the translocation of CFTR to the apical membrane of gallbladder cells. Moreover, TGR5 was shown to mediate bile-acid-induced suppression of LPS-induced cytokine secretion in macrophages. Thus, we hypothesize that, similar to the mechanism we have shown for CFTR, TGR5 modulates the innate immune response in cholangiocytes, and that defective function of TGR5 my lead to an excessive inflammatory response to LPS.

The hypothesis will be addressed through the following specific aims:

Aim 1: to study the effects of DSS-induced colitis on biliary inflammation in TGR5-KO mice.
Aim 2: to study the effects of LPS on cytokine secretion in cultured TGR5-KO and WT cholangiocytes.
Aim 3: to study the role of TGR5 on TLR4 pathway regulation in cultured TGR5-KO and WT cholangiocytes.

These studies will generate a better understanding of the innate immune response mechanisms in cholangiocytes and of the pathogenesis of PSC. Furthermore, the results of our study are likely to have a strong translational potential because several therapeutic molecules able to target these mechanisms are being developed.

Interpretation for the Layperson

One of the explanations for the cause of PSC (primary sclerosing cholangitis) in association with inflammatory bowel disease (IBD) is that an immune dysregulation in the gut leads to a “leaky gut” which allows toxic bacterial products to be transported to the liver, causing inflammation around the bile ducts. Both genetic and environmental factors may be involved in disease development and progression. It is essential that we understand the precise causes of PSC, so that we can ultimately learn how to slow or halt disease progression. Significant progress has been made in recent years concerning the identification of genes that may be associated with PSC. An important research approach is to take information obtained from these human PSC genetic studies to develop mouse models that mimic human PSC. Such models will be critical in understanding the pathogenic mechanisms, and accelerating the development of novel therapies. One of the exisiting mouse models of PSC is the cystic fibrosis mouse model. When given colitis, the cystic fibrosis transmembrane conductance regulator (CFTR) deficient mouse develops bile duct injury closely resembling human PSC. The CFTR gene encodes a protein that functions in bicarbonate secretion into bile. This mouse model has already been used to show that docosahexaenoic acid (DHA; a component of fish oil) protects against bile duct injury, and has led to clinical trials of DHA in the treatment of PSC. The relevance of this mouse model to human PSC is that variants of the cystic fibrosis gene have been associated with PSC, and pediatric PSC patients have been shown to have a dysfunction of the cystic fibrosis protein.

The TGR5 gene has been recently identified as a strong candidate for a susceptibility gene in PSC by the Norwegian PSC research center. The TGR5 gene encodes a protein that is a “bile acid sensor” and a regulator of the cystic fibrosis protein. To learn more about what TGR5 is doing, the researchers will use mice in which TGR5 has been knocked-out, and study whether the mice develop sclerosing cholangitis. Drs. Strazzabosco and Trauner will test whether deleting the TGR5 gene in mice will result in an abnormal inflammatory response to the bacterial product lipopolysaccharide (LPS; also known as endotoxin). A characteristic feature of inflammation caused by endotoxin is the activation of the pro-inflammatory complex, nuclear factor kappa-B (NF-kB). Endotoxin binds to the Toll-like receptor 4 (TLR4) and activates NF-kB. Thus, the assessment of the effect of deletion of TGR5 on TLR4-NF-kB pathway regulation in biliary cells (cholangiocytes) will provide important information about the inflammatory mechanisms controlled by TGR5. Drugs that target TGR5 are already in development, and so this study will pave the way for testing whether these drugs may inhibit liver inflammation. Drs. Strazzabosco and Trauner have extensive experience working with mouse models of sclerosing cholangitis, and have been instrumental, respectively, in clarifying the disease mechanisms in biliary tract diseases, and in demonstrating that nor-ursodeoxycholic acid (nor-UDCA) is superior to ursodeoxycholic acid (UDCA) in preventing liver injury, and bringing nor-UDCA to human clinical trials.

The first year of this project will be funded by a generous donation from Craig and Ali Wiele.

Epigenetics associated with primary sclerosing cholangitis in monozygotic twins discordant for the disease.

Carlo Selmi, MD, PhD, Assistant Professor of Internal Medicine, University of Milan, Physician Scientist, IRCCS Istituto Clinico Humanitas, Rozzano, Milan, Assistant Professor of Medicine, University of California, Davis, Division of Rheumatology, Allergy, and Clinical Immunology, GBSF suite 6515, 451 E Healthy Sciences Drive, Davis, CA 95616. Amount awarded = $40,000 over 2 years.

Summary

Primary sclerosing cholangitis (PSC) is characterized by the presence of a chronic and relapsing inflammation of the biliary tract. As illustrated by recent association studies, genomic factors cause individual susceptibility in a subgroup of patients. Monozygotic (MZ) twins are a powerful tool to estimate the role of genetic and environmental factors, yet the concordance rate for PSC in such twins is unknown. Epigenetic changes are ideal candidates to provide a link between genomic susceptibility and environmental stimuli, particularly in the unique model of MZ twins discordant for the disease. We will take advantage of MZ twins discordant for PSC to utilize cutting-edge technologies which allow a large-scale analysis of epigenomics to address two specific issues:

Issue #1. Do MZ twins discordant for PSC manifest consistent patterns in terms of DNA methylation changes within repetitive and non-repetitive elements? We will utilize custom-designed MeDIP multiplex arrays for non repetitive and the most represented repetitive elements (LINE-1, Alu). Issue #2. Does the expression of candidate genes identified through the previous aim differ between discordant MZ twins? We will utilize RTPCR on mRNA samples and then pinpoint methylation differences through bisulfite sequencing. Issue #3. Is there an in silica disease model that can be summoned from the identified putative genes? The results obtained are expected to provide insights into putative epigenetic marks implicated in PSC onset that may well be integrated with the recently identified genetic loci. These results ultimately provide the bases for new epigenetic treatments in inflammatory conditions.

Specific Aims

We will take advantage of samples already available to the proponent from 6 MZ twin pairs discordant for PSC. Samples include DNA, mRNA, and mononuclear cells from peripheral blood and were previously obtained by the proponent through a worldwide effort supported by PSC Partners Seeking a Cure. We will take advantage of this unique cohort and of cutting-edge molecular methods to address two complementary and one ultimate issue.

Issue #1. Do MZ twins discordant for PSC manifest consistent patterns in terms of DNA methylation changes within repetitive and non-repetitive elements? Issue #2. Does the expression of candidate genes identified through the previous aim differ between discordant MZ twins? What is the methylation pattern of single CpG sites within differently expressed genes? Issue #3. Is there an in silica disease model that can be summoned from the identified putative genes? This analytical step will include data from the recently concluded genome-wide genetic association study as well as from the present proposal. Such findings will be utilized with the appropriate bioinformatics tools to determine what molecular pathways are involved in PSC pathogenesis or whether a genetic signature can be extrapolated.

Interpretation for the Layperson

It is estimated that first-degree relatives of PSC patients have a 40-fold higher risk of developing PSC than the general population. Therefore there is a strong genetic component to PSC. The genetic basis of PSC is likely to be complex involving more than one gene and may well be insufficient to explain disease onset. There may also be as yet unknown environmental factors contributing to disease initiation and progression. At the interface between genetics and environment is a relatively new field of research called “epigenetics”. Here, certain gene modifications can take place, such as methylation of cytosine residues of DNA, converting cytosine to 5-methylcytosine, mostly at sites called “CpG sites”. When some areas of the genome are methylated more heavily than others this can alter gene expression and thus the production of the corresponding protein. A key approach to discovering whether epigenetic changes are involved in disease development/progression is to carefully examine the DNA methylation patterns of monozygotic twins (i.e. twins that are genetically identical) but differ with respect to disease (i.e. only one twin is affected, and the pair is thus discordant for disease). This approach has been used by Dr. Selmi and colleagues to investigate the role of “epigenetics” and DNA methylation in particular, in primary biliary cirrhosis (PBC), a liver disease that mostly affects women. These pioneering studies have recently shown that monozygotic twins that are discordant for PBC have distinct methylation patterns of certain genes on the X chromosome. Dr. Selmi and colleagues will now extend these studies to investigate DNA methylation patterns in 6 pairs of monozygotic twins discordant for PSC, recruited with the assistance of PSC Partners Seeking a Cure. The results of this project are expected to provide insights into putative epigenetic markers implicated in PSC onset, painting a more complete picture of the genetic landscape of PSC and its interface with environmental exposures. These results may ultimately provide the basis for novel epigenetic treatments.

Identification of genetic profiles unique to PSC-IBD.

Judy Cho, M.D., Associate Professor of Medicine and Genetics, Section of Digestive Diseases, Director, Inflammatory Bowel Disease Center, Yale University, Internal Medicine, 333 Cedar Street, Room LMP-1072, P.O. Box 208056, New Haven, CT 06520-8056. Amount awarded = $40,000 over 2 years.

Project Summary

The primary goal of this proposal is to better understand the relationship between the primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD). We propose to accomplish this by identifying the genetic and genomic factors which contribute to the cause of PSC-IBD, and comparing this to identified genetic and genomic factors associated with Crohn’s disease (CD) and ulcerative colitis (UC). Identification of these factors will ultimately contribute to better screening for disease risk, improve predictions of disease severity, influence treatment regimens and advance therapies for treatment and quality of life care. PSC-IBD is poorly characterized, clinically and genetically. A strong association has been observed with IBD and PSC, some analyses identified IBD in 80-90% of PSC patients. Conversely, about 5% of UC patients will have associated PSC compared to 3.4% of CD patients. Genetic contributions to both have been confirmed epidemiologic studies and by the identification of genetic associations for both IBD and PSC. A recent GWAS found the strongest PSC association for the HLA-B region at chromosome 6p21, and some evidence for associations at 2q35, 3p21 and 13q31. Interestingly, significant associations were not found for confirmed UC susceptibility loci. These observations underlie PSC and IBD as complex genetic traits, and support the hypothesis that PSC-UC is a distinct sub-phenotype of IBD. We plan to advance the genetic and genomic knowledge in PSC-IBD by expanding the collection of PSC-IBD cases and biospecimen collections (Specific Aim #1). We propose to compare and contrast both the genetic loci (Specific Aim #2) and peripheral blood serum miRNA patterns (Specific Aim #3) between PSC and IBD. The unique relationship between PSC and IBD provides an ideal opportunity to leverage these comparative studies to provide insight into disease mechanisms and course.

Specific Aims

Specific Aim #1: Development and expansion of PSC-IBD resources for collaborative genetic and genomic studies. We propose to recruit patients and collect phenotype data and biospecimens from individuals with PSC-IBD using uniform protocols to enhance collaborative studies. Identification and a better understanding of the genetic factors contributing to PSC-IBD will greatly increase the potential for identifying disease predictors/markers, novel therapies for disease management and/or the prevention of invasive treatments.

Specific Aim #2: To compare and contrast genetic loci between PSC and IBD. The Immunochip Consortium has developed a genotyping platform which includes all inflammatory disease loci, many of which are shared between different diseases. We propose studies to define the genetic overlap between PSC and IBD, with a particular focus on combining PSC data with two IBD subtypes, namely,extensive colitis and fibrostenosing CD.

Specific Aim #3: To compare and contrast peripheral blood serum miRNA patterns between PSC and IBD. We propose a pilot study to explore the feasibility of using micro-RNAs as biomarkers for PSC-IBD. The analysis of miRNAs in peripheral blood may provide an important and novel source for biomarkers. At present the extent to which small RNAs can be specifically mapped to and regulate, protein-coding mRNA expression is unknown. However, given the plethora of SNP associations in 3’UTR regions, specifically for IBD, the concept that disease-associated variation may modulate mRNA expression through variable miRNA regulation of genetic variation will be explored. We propose an initial analysis of circulating miRNA from serum of CD, UC, PSC-IBD cases and healthy controls.

Interpretation for the Layperson

PSC (primary sclerosing cholangitis) is strongly associated with inflammatory bowel disease (IBD), particularly ulcerative colitis (UC). Both genetic and environmental (possible also dietary) factors may be involved in disease development and progression. Much work during the last decade by the NIDDK Inflammatory Bowel Disease Genetics Consortium (led by Dr. Judy Cho [http://medicine.yale.edu/intmed/ibdgc/]) has identified a multitude of genes associated with UC and Crohn’s disease. The identification of these genes is leading to a more complete understanding of the mechanisms of UC and Crohn’s disease initiation and progression, and identification of new targets for intervention, and novel therapies for disease management. Parallel studies on the genetics of PSC are beginning to reveal that the IBD associated with PSC may have a different genetic signature from classic UC and Crohn’s disease. Dr. Judy Cho will rigorously investigate this important question by recruiting patients and collecting phenotype data and biospecimens from individuals with PSC-IBD for comparison with classic UC and Crohn’s disease patients, and healthy controls. Dr. Cho will use the “Immunochip” [which includes all known inflammatory disease genes] to investigate the precise genetic overlap between PSC and the various forms of IBD.

There is recent interest in whether microRNAs (small RNA molecules with potent gene regulatory functions) play a role in IBD and PSC [Dr. Invernizzi at UC Davis is currently funded by PSC Partners Seeking a Cure to investigate whether specific microRNAs are associated with PSC and cholangiocarcinoma]. Dr. Cho will extend this work to determine if circulating microRNAs in the serum of Crohn’s disease, UC, and PSC-IBD patients differ from one another, and from healthy controls. This work may lead to new diagnostic tools, perhaps enabling early identification of UC and Crohn’s disease patients who may be at risk for developing PSC.

This project will be entirely funded by our anonymous donor who generously donated $100,000 in our Itching for a Cure: Road to Connecticut fundraiser of 2009/2010 to help support PSC research.

Combination treatment with ursodeoxycholic acid and all-trans retinoic acid for primary sclerosing cholangitis (PSC).

Shi-Ying Cai, Ph.D., Research Scientist, Section of Digestive Diseases, Department of Internal Medicine, Yale Liver Center, Yale University School of Medicine, 1080 LMP, 333 Cedar Street, New Haven, CT 06520, and James L. Boyer, M.D., Ensign Professor of Medicine, Section of Digestive Diseases, Department of Internal Medicine, Yale Liver Center, Yale University School of Medicine, 1080 LMP, 333 Cedar Street, New Haven, CT 06520. Amount awarded = $37,000 over 2 years.

Project Summary

Primary sclerosing cholangitis (PSC) is a chronic cholestatic disease of the liver and bile ducts that generally leads to progressive liver failure. The pathogenesis of PSC remains enigmatic, but malfunction of hepatic immunity has been proposed to play a role in the development/progression of the disease. There is no FDA approved medical treatment for PSC. Although norUDCA has shown beneficial effects in Mdr2 (Abcb4) knockout mice (an animal model for PSC), there is an urgent need to develop novel treatment strategies and to test them in animal models and in PSC patients. Very recently, we have found that combination treatment with UDCA and retinoic acid substantially improved animal growth rate and significantly reduced bile salt pool size, liver fibrosis, necrosis, inflammation, and bile duct proliferation in an animal model of cholestasis, the common bile duct ligated rat. (UDCA and retinoic acid are FDA-approved medications for treating primary biliary cirrhosis and acute promyelocytic leukemia and inflammatory disorders such as psoriasis, acne, and rheumatoid arthritis, respectively). Parts of the molecular mechanisms of this beneficial effect of UDCA and retinoic acid have also been verified in primary human liver cells, including hepatocytes and hepatic stellate cells (manuscript submitted for publication). Therefore, we propose to test if RA alone or in combination with UDCA will improve liver pathology in Mdr2-/- mice. Completion of the proposed study will provide critical information for determining whether RA alone or in combination with UDCA might be potentially beneficial for patients with PSC. If this project demonstrates beneficial effects in this animal model, we plan to test this therapy in patients with PSC.

Specific Aims

The specific aim of this study is to determine whether RA alone or in combination with UDCA has beneficial effects on liver fibrosis, necrosis and or inflammation in Mdr2-/- mice, an animal model for PSC.

Interpretation for the Layperson

It is urgent that novel therapies/treatment strategies be developed for PSC, and the use of mouse models of sclerosing cholangitis will be critical in accelerating the discovery and pre-clinical testing of these new approaches. It is well recognized that vitamin A deficiencies are common in PSC patients, and that the deficiencies become more pronounced as the disease progresses. The liver is a major storage organ for vitamin A, and as cholestatic liver diseases progress, this vitamin A can be released from the vitamin A storing cells of the liver (hepatic stellate cells) as they transition away from vitamin A storage towards a state that promotes collagen biosynthesis and liver fibrosis. Vitamin A (retinol) is a precursor of all-trans retinoic acid (RA), and so loss of vitamin A during advancing liver disease may lead to retinoic acid deficiencies, which may in turn contribute to a vicious cycle of inflammation, necrosis and fibrosis. In this proposal, Drs. Cai and Boyer will test whether the combination of ursodeoxycholic acid (UDCA) with retinoic acid (RA) will be superior to the individual drugs alone in delaying liver fibrosis, necrosis and inflammation in a mouse model of sclerosing cholangitis, the Mdr2 (-/-) mouse model. Should positive results be obtained in these studies, this combination therapy can be immediately tested in patients with PSC.

This project will be entirely funded by our anonymous donor who generously donated $100,000 in our Itching for a Cure: Road to Connecticut fundraiser of 2009/2010 to help support PSC research.

Establishing the role and molecular mechanisms for pregnane X receptor in progressive sclerosing cholangitis. Sridhar Mani, M.D., Professor, Medicine, Oncology and Genetics, Miriam Mandel Faculty Scholar in Cancer Research, Albert Einstein College of Medicine, 1300 Morris Park Ave, Chanin 302D-1, Bronx, NY 10461. $40,000 over 2 years.

Project Summary

We and others have demonstrated that orphan nuclear receptors like pregnane x receptor (PXR) abrogates intestinal inflammation induced by xenobiotic compounds (e.g., DSS). These experiments serve as a proof-of-concept that PXR plays a significant role in pathogenic diseases of the gut that result from unregulated inflammatory responses (e.g., IBD). Fish oils have beneficial effects on inflammation and are relatively non-toxic xenobiotics. Since the pathogenesis of progressive sclerosing cholangitis is parallel to that observed in arteriosclerotic inflammation (where fish oils show clear benefit), our 2-year project will focus on determining the significance of PXR activation in the pathogenesis and maintenance of PSC. Specifically, we will use the DDC-induced mouse model of cholangiopathy in our mouse models of PXR activation [PXR wt type, PXR-/- and humanized (h)PXR] to determine if PXR activation by non-hepatotoxic agonists (e.g., hyperforin or rifampicin) abrogates biliary inflammation. In our second aim, we will determine whether PXR mediates the actions of fish oils in abrogating biliary inflammation. Specifically, we hypothesize that fish oils will transactivate PXR and inhibit inflammation.

Specific Aims

  1. To determine the effect of PXR activation on biliary inflammation in the DDC-induced mouse model of cholangiopathy in PXR+/+, PXR-/- and humanized PXR mice. DDC induces a cholangiopathy in mice at 8 weeks of treatment that resembles early inflammatory changes seen in PSC. (a) To determine the effect of PXR on early inflammation in the bile duct tract, PXR +/+ will be treated with DDC (+ PCN, a potent mPXR agonist). At 4, 6 and 8 weeks, cohorts of mice from each genotype, will undergo histopathologic and immunohistochemistry assessment of the entire bile duct tract (intra- and extrahepatic) as previously described. (b) The same experiments will be repeated with PXR-/- and hPXR mice (+ hyperforin or rifampicin, potent hPXR agonists), with accurate sample size estimates obtained from data from (a). These experiments will determine the clinical impact of PXR in biliary inflammation as typified in PSC.
  2. To determine the therapeutic efficacy of fish oils alone or in combination with classical PXR ligands on DDC-induced mouse models of cholangiopathy. Fish oils (DHA, EPA) are commercially available and serve as weak ligands to several nuclear receptors – RXRalpha and PPARalpha. Since PXR dimerizes with RXRalpha and is a direct target gene of PPARalpha, we hypothesize that fish oils will transactivate PXR and inhibit inflammation. Furthermore, we surmise that multiple ligands acting on PXR, given its promiscuous ligand-binding pocket, will synergistically activate PXR and inhibit inflammation. To test this concept, we will treat PXR+/+, PXR-/- and humanized PXR mice with vehicle, fish oils and/or PCN (as mPXR ligand) or rifampicin (as hPXR ligand).

Interpretation for the Layperson:

It is becoming clear that there is a complex network of nuclear receptors in the gut and liver that are “master” controllers of gene expression, regulating all aspects of metabolism, ranging from bile acid transport and detoxification, to energy metabolism, to lipid metabolism, and circadian rhythms (day-night cycles). An important “master” contoller is the receptor called pregnane X receptor (PXR), also known as the steroid and xenobiotic receptor (SXR). PXR is known to be down-regulated in ulcerative colitis, and the PXR gene itself may be an ulcerative colitis susceptibility gene, and a gene that affects the rate of progression of PSC. This receptor plays an important role in detoxification of lithocholic acid, a toxic bile acid produced from ursodeoxycholic acid (UDCA) by gut bacteria. Recent studies indicate that activation of PXR by drugs such as rifampin (rifampicin) and rifaximin results in reduction of inflammation and fibrosis.

Because the adverse effects of high-dose UDCA in PSC may be associated with conversion of UDCA to lithocholic acid, there is also particular urgency in investigating whether drugs that target PXR may help prevent these adverse effects of UDCA.

In this proposal, Dr. Mani will use humanized mice in which the mouse PXR gene has been replaced with the human PXR gene so that it responds to rifampin (rifampicin), and will then test whether activation of PXR by rifampin will result in a reduction of biliary inflammation.

Another “master” controller of gene expression in the liver and gut is the receptor called retinoid X receptor (RXR), which partners with PXR (and many other nuclear receptors) to regulate metabolism. A known activator of RXR is a component of fish oil, docosahexaenoic acid (DHA). It is plausible that the combination of DHA and rifampin, as activators of both RXR and PXR, respectively, will be superior to either drug alone in reducing inflammation. Dr. Mani will test this hypothesis. If positive results are obtained, this may lead to novel therapies in PSC, perhaps combining UDCA with rifampin and DHA. It should be noted that rifampin is already used by many PSC patients for the control of pruritus, and that DHA has shown some early positive results in reducing alkaline phosphatase levels in PSC patients. Some mouse models suggest that DHA may be protective against colitis and colorectal cancer, and there is growing evidence that human ulcerative colitis may be associated with low intake of omega-3 fatty acids such as those found in fish oils.

Awarded in 2009

Eight awards were selected for funding for two years each.

  • Examining the Disease Impact of Genetic Variation in Logical Candidate Genes for PSC: a PROGRESS Study.Project Summary: Genetic predisposition is thought to play a key role in the susceptibility to primary sclerosing cholangitis (PSC). However, the rarity of PSC has rendered the collection of sufficient multiply-affected families to perform traditional genetic analyses impossible, hampering efforts to identify the associated genetic variants. To this end, we established the PSC Resource Of Genetic Risk, Environment and Synergy Studies (PROGRESS) registry and biorepository, a national research resource aimed at elucidating the genetic and environmental contributors to PSC by combining association-based study designs with cutting-edge and emerging approaches to their analysis. We are now in the position to utilize PROGRESS for genetic studies and have elected to focus on highly selected, biologically plausible candidate genes. This logical candidate gene approach remains important in the era of genome-wide studies as it provides for superior gene coverage and a more subtle appreciation of disease affects for these highly suspect genes than afforded by the more comprehensive studies. Moreover, this genetic information may prove valuable to future gene-gene and geneenvironment interaction studies, even when no primary association is identified.
  • Our seminal effort has identified a strong association between PSC and a promoter polymorphism in the tumor necrosis factor alpha (TNFalpha) gene. Here we propose to build upon this finding by genotyping haplotype tagging single nucleotide polymorphisms (SNPs) in a number of PSC candidate genes, performing association analysis for disease status as well as subphenotypes of disease, and exploring potential gene-gene and gene-environment interactions by utilizing the unique resource available to us in the PROGRESS registry and biorepository.
  • Konstantinos N. Lazaridis, M.D., Assistant Professor of Medicine, Center for Basic Research in Digestive Disease, Mayo Clinic College of Medicine 200 First Street SW, Rochester, MN 55905.
  • Cholangiocarcinoma-associated serum microRNAs in primary sclerosing cholangitis: Identification and prognostic potential.Project Summary: Primary sclerosing cholangitis (PSC) is associated with a high risk of cholangiocarcinoma (CCA), a rare but often fatal malignancy of the bile duct epithelium. Several tumour markers have been used to aid diagnosis, but no useful markers specific for CCA are currently available. Because of the ease of obtaining blood samples, there is an obvious need for accurate serum markers for screening of CCA in PSC patients at an early stage of this cancer or, even better, for pre-cancer biomarkers. MicroRNAs (miRNAs) are a group of endogenous small non-coding RNAs involved in the control of cell differentiation processes, and consistently with this they have been demonstrated to be useful cancer biomarkers. Recently, this emerging field of study has discovered that miRNAs can also be efficiently evaluated in serum. The aim of the project is to identify specific serum miRNAs with a role as pre- or early-cancer biomarkers for human CCA in patients with PSC. The project will be divided in two phases: (i) In the first phase (first year) we will investigate the miRNAs expression profile (1) in available serum from 30 patients with CCA, 30 with PSC, and 30 healthy subjects, matched by sex and age to CCA patients, (2) in five human CCA immortalized cell lines and one normal immortalized biliary epithelial cells (BECs) line, and (3) in available human primary BECs cultures from CCA, PSC and normal subjects (ii) In the second phase (second year) we will take advantage of an extraordinary unique multi-center series of PSC sera (n=400) collected in tertiary referral liver centers in USA, Italy, and Norway in order to evaluate with a longitudinal (retrospective/prospective) study the role as pre- or early-cancer biomarkers of the CCA-specific miRNAs identified in the phase 1 of the study.
  • Pietro Invernizzi, M.D., Ph.D., Assistant Professor of Medicine, Division of Rheumatology, Allergy, and Clinical Immunology, University of California, Davis GBSF suite 6515, Davis, CA 95616. [Collaborators: Kirsten M. Boberg, M.D., Ph.D. (Medical Department, Rikshospitalet University Hospital, Oslo, Norway); Gianfranco Alpini, Ph.D. (Research, Central Texas Veterans Health Care System and Department of Medicine, Central Texas Veterans HCS and Texas A&M HSC COM, Scott & White Hospital, Temple, TX); Antonio Benedetti, M.D. (Department of Gastroenterology, University “Politecnica delle Marche”, Ancona, Italy); Domenico Alvaro, M.D. (Department of Gastroenterology, Universita “La Sapienza”, Roma, Italy); Guido Torzilli, M.D. (Liver Surgery Unit, Department of Gastroenterology, IRCCS Istituto Clinico Humanits, University of Milan, Rozzano, Italy)]
  • Aberrant homing of lymphocytes to the liver in patients with primary sclerosing cholangitis; the missing link between colon and liver.Project Summary: Primary sclerosing cholangitis (PSC) is a rare chronic inflammatory disease of the biliary tree leading to bile duct strictures, to fibrosis and cirrhosis of the liver and eventually to liver failure. The etiopathogenesis is unknown. There is no medical therapy of proven benefit for the long-term prognosis so far. Liver transplantation is the treatment of choice in late stage disease. PSC is highly associated with inflammatory bowel disease (IBD). It was proposed that T lymphocytes primed to home to gut tissue, by mistake instead home to the liver in PSC, thereby keeping the chronic inflammation ongoing. It was hypothesized that erroneous homing of gut-primed lymphocytes in PSC is caused by aberrant over-expression or functioning of the chemokines, integrins, or addressins involved in transendothelial migration of gut-homing T-cells. We hypothesize that this may occur through functional gene mutations.A cohort of greater than 400 PSC patients with detailed phenotyping and appropriate controls (primary biliary cirrhosis, IBD-patients and healthy partners) is being accrued from 42 hospitals in central-Netherlands. The expression of CCL25, CCR9, alpha4Beta7, and MAdCAM-1 will be studied as candidate chemotactic factors in cases and controls by immunohistochemical expression in PSC liver and colon tissue, as compared to control tissues. Peripheral blood and colonic lamina propria lymphocytes (PBL and LPL) will be harvested and analyzed by FACS to examine the expression of CCR9 and alpha4Beta7.
  • Potential relevance of our research will be 1. to ascertain the gut-homing lymphocyte paradigm in the IBD-PSC association; 2. to assess the presence of PSC associated gut-homing chemokines, addressins and integrins in colonic tissue; 3. to pinpoint the role of CCL25, CCR9, alpha4Beta7, and/or MAdCAM-1 in the pathogenesis and/or sustaining of inflammation in PSC. This will lend support to initiate trials in PSC with specific inhibitors of gut-homing chemotaxis such as natalizumab and Traficet; 4, the building of a large population-based PSC cohort including biobanking for future studies.
  • The topic of our research project is to study location-specific expression of these chemotactic molecules in PSC, in particular to prove that there is colonic expression of CCL25.
  • Cyriel Y. Ponsioen, MD, PhD, Department of Gastroenterology & Hepatology, Academic Medical Center, C2-112, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands. [Collaborators: Kirsten Boonstra, Ph.D. student, Department of Gastroenterology & Hepatology, C2-231; Anje A. te Velde, Ph.D., Department of Experimental and Molecular Medicine, H2-256; Prof. Ulrich Beuers, M.D. Ph.D., Department of Gastroenterology & Hepatology, Academic Medical Center, C2-321, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands]
  • alpha4Beta7-Integrin Ligand Development for the Treatment of PSC.This project will be entirely funded by a generous donation from Abe and Rachel Gomel.
  • Project Summary: Primary sclerosing cholangitis (PSC) is due in part to gut-derived lymphocytes trafficking to the liver in response to specific adhesion molecules and chemokines normally expressed in the gut. Specifically, alpha4Beta7-integrin expressing lymphocytes home to the PSC liver where its ligand mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is aberrantly expressed. Blocking alpha4 integrins has been successfully targeted by monoclonal antibodies for the treatment of Crohn’s disease. However, the use of this therapy in PSC is hindered by the risk of progressive multifocal leukoencephalopathy (PML), believed to be due to the lack of specificity for alpha4Beta7. Vedolizumab (formerly known as MLN002 and MLN02), is a monoclonal antibody with specificity for alpha4beta7 that has shown efficacy in phase 2 clinical trials of moderately active ulcerative colitis and Crohn’s disease. However, monoclonal antibodies have limitations. The antibody molecule is relatively large with a molecular weight of 160,000 kD requiring infusion or subcutaneous injection. In addition, even with humanized forms of these monoclonal antibodies, human anti-chimera antibodies (HACA) are frequently generated and are sometimes associated with a lower rate of response. Peptides are considerably smaller than monoclonal antibodies and generally do not illicit a humoral immune response. They are chemically stable and relatively easy to derivatize. Although peptides are susceptible to proteolytic degradation in vivo, this can be inhibited with blocking of their N- and C-termini, making them cyclized, or incorporating D-amino acids. 
In this proposal, we will take advantage of our expertise in One Bead-One Compound (OBOC) combinatorial chemistry, integrin biology, immunology and PSC to identify novel lead compounds for the treatment of PSC. We have previously identified a high affinity, high specificity peptidomimetic ligand for alpha4Beta1-integrin that is currently under pre-clinical development. In this project we will use the same technology to identify lead compounds for alpha4Beta7 ligands. In Aim 1 we will design and synthesize a diverse combinatorial chemistry library based upon the known alpha4Beta7 binding motif. In Aim 2 we will use a whole cell method to screen this library with alpha4Beta7+ T cells from PSC patients. The specificity and binding affinity of these lead compounds will be assessed in Aim 3. Upon completion of this project we will have identified lead compounds that will be ready to proceed to functional testing. In addition, the knowledge gained will be used to design focused libraries which will be screened for additional ligands.
  • Christopher Bowlus, M.D., Associate Professor, Division of Gastroenterology, UC Davis Medical Center, 4150 V Street, PSSB 3500, Sacramento, CA 95817 [Collaborators: Ruiwu Liu, Ph.D. Assistant Research Chemist, University of California, Davis, 2700 Stockton Blvd., Suite 1400, Sacramento, CA 95817; Kit S. Lam, M.D., Ph.D., Professor and Chief, Division of Hematology and Oncology, UC Davis Cancer Center, 4501 X St., Sacramento, CA 95817; Mark Kurth, Ph.D., Professor, Department of Chemistry, University of California, Davis, CA 95616; Yoshikazu Takada, M.D., Ph.D., Professor, Department of Dermatology, University of California Davis Medical Center, Research III Suite 3300, 4645 2nd Avenue, Sacramento, CA 95817]. $40,000 over 2 years.
  • Non-invasive Assessment of Disease Progression in Primary Sclerosing Cholangitis. Project Summary: Current methods for monitoring primary sclerosing cholangitis (PSC) disease progression are insensitive, invasive, and nonspecific. We have developed a novel noninvasive technique to accurately measure liver function by quantifying portal-systemic shunting, the cholate shunt test. Our overriding hypothesis is that our liver function test will accurately monitor PSC disease progression.
  • Gregory T. Everson, M.D., Transplant Center and Hepatology, Clinic Mail stop B, 154 Anschutz Outpatient Pavilion, 1635 N. Ursula Street, Room 7085, Aurora, CO 80045. [Collaborators: Steve Helmke, Ph.D.; Lisa Forman, M.D.]. $40,000 over 2 years.
  • The Role of Abcb11 and Fibroblast Growth Factor 15/19 in the Pathogenesis of Primary Sclerosing Cholangitis.This project will be entirely funded by a generous donation from David and Ros Parry.
  • Project Summary: Primary sclerosing cholangitis (PSC) is a hepatic disease of unknown etiology that can lead to cirrhosis, cholangiocarcinoma and the need for liver transplantation. It is characterized by inflammation and fibrosis of cholangiocytes, the cells that compose the liver bile ducts. Unfortunately, no effective therapy has been shown to slow disease progression, in part because the pathogenesis of primary sclerosing cholangitis remains poorly understood. By enhancing our understanding of the pathogenesis of PSC, one can better design rational therapies for this potentially devastating form of chronic liver disease. 
The cholangiocytes that form the bile ducts are exposed to extremely high concentrations of bile salts, which induce signaling changes in cholangiocytes. The high bile salt concentrations in bile are created by the ATP-dependent secretion of bile salts from the liver into the biliary system. Our laboratory has a long-standing interest in identifying the mechanisms by which hepatocytes (liver cells) secrete bile salts into the biliary system. We, along with other investigators, have determined that bile salts are secreted by the liver canalicular membrane transporter Abcb11. Furthermore, we have cloned Abcb11 and developed a transgenic mouse that over-expresses Abcb11 in the liver. In addition, the level of expression of Abcb11 in humans is highly variable (by a factor of over 10) and therefore it is likely important in the manifestation of many cholestatic liver diseases. However, the impact of high levels of Abcb11 expression on primary sclerosing cholangitis is poorly understood. 
A recently identified gut-derived hormone named fibroblast growth factor 15/19 (FGF15/19) is secreted by the ileum in response to bile salt stimulation and subsequently interacts with hepatocytes and cholangiocytes to regulate their function and maintain normal cellular homeostasis. Although FGF15/19 has been shown to be an important physiologic regulator of ductular cells in the gallbladder and for gallstone formation, the function of FGF 15/19 in other biliary tract diseases remains unknown. In the proposed studies, we will explore the role of Abcb11 and FGF 15/19 in biliary tract disease; since our enhanced understanding of these physiologic processes will allow for the design of rational, novel therapeutic targets for treating patients with PSC
  • Richard M. Green, M.D., Associate Professor of Medicine, Division of Hepatology, Northwestern University Feinberg School of Medicine. $40,000 over 2 years.
  • A Pilot study of Vancomycin or Metronidazole in patients with Primary Sclerosing Cholangitis.Project Summary: Primary Sclerosing cholangitis (PSC) is a progressive liver disease without effective medical treatment. Although treatment with ursodeoxycholic acid (UDCA) improves serum liver tests and is prescribed frequently for PSC patients, this drug appears to have no beneficial effect on the course of the disease. Recent results of UDCA used in high doses have been most disappointing. 
Various antibiotics have been tested sporadically for the treatment of PSC over the years with promising results reported. The numbers of cases were small, sometimes single case reports, and the duration of follow up has been variable but often short. In the current protocol, we propose the assessment of potential beneficial effects of the antibiotics vancomycin and metronidazole on liver biochemistries, liver related symptoms and Mayo risk score in 40 patients with PSC. The patients will be randomized into four groups of ten patients: one group will receive low dose vancomycin, one group will receive high dose vancomycin, one group will receive low dose metronidazole and one group will receive high dose metronidazole. Each group will be treated for three months. Liver biochemistries, C-reactive protein (CRP) and Mayo risk score will be determined at three weeks and three months and compared to baseline values as well as values at 3 months in the placebo group (n=74) from the recent high dose UDCA study. A positive study based on significant liver biochemical improvement will establish the basis for further evaluation of one or both antibiotics in a larger number of patients for a longer time period within a randomized controlled trial.
  • Keith D. Lindor, M.D., Mayo Clinic, 200 First Street, SW, Rochester, MN 55905. [Collaborators: Marina G. Silveira, M.D.; Andrea Gossard, C.N.P.; Roberta Jorgensen, R.N.; Jill C. Keach; Janice Petz, R.N., Division of Gastroenterology and Hepatology, Mayo Clinic and Foundation, Rochester, Minnesota]. $25,706 over 2 years.
  • Quality of life in patients with primary sclerosing cholangitis.This project will be funded in large part by a generous donation from Hoops 4 Healing  (http://www.hoops4healing.org/).Although many patients with PSC in time will go on to need liver transplantation for liver failure related complications, reductions in quality of life are important on an individual basis. The slow natural history of the disease means that quality of life concerns can have significant impact on patients and their families over many years. Symptom evaluation is often poorly performed in routine clinic practice and frequently underestimated by clinicians. Abdominal pain, fatigue, itch, and anxiety are commonly voiced by patients with PSC. This reflects both the nature of a chronic cholestatic liver disease, but also the significant uncertainty associated with a diagnosis of PSC. No disease specific tool exists to help patients and their clinicians quantify symptoms and measure quality of life for these patients in a reproducible, objective fashion. Furthermore no tool is available to aid in the development of new treatments for this disease, the efficacy of which should include evaluation of patient defined quality of life.
  • Our proposal will evaluate patients with PSC both before and after liver transplant, in two clinic practices in Ontario, and identify symptoms and concerns that are relevant to patients. By correlation with clinical aspects of disease we hope to identify major factors of concern to patients, and use these to ultimately develop a disease specific quality of life tool.
  • Project Summary: We aim to prospectively evaluate quality of life in patients with primary sclerosing cholangitis (PSC) as a means to better understand the global experience faced by patients with this disease.
  • Gideon Hirschfield, MA MB BChir MRCP PhD, Assistant Professor of Medicine, University of Toronto, Liver Centre, Toronto Western Hospital 399 Bathurst St, 6B Fell, Rm 162, Toronto, ON, M5T 2S8, Canada. [Collaborators: Natasha Chandok, MD FRCPC, Adjuvant Professor of Medicine, University of Western Ontario; Maria Cino, MD FRCPC, Assistant Professor of Medicine, University of Toronto]. $10,000 over 2 years

Grants Awarded Through the AASLD Foundation

As the official Foundation of the American Association for the Study of Liver Diseases (AASLD), the AASLD  Foundation invests in innovative hepatology research and in the people who study and treat liver disease. The Foundation seeks to save lives by aggressively pursuing the prevention and ultimate cure of liver disease and aims to inspire the next generation of hepatologists by supporting innovative research and connecting young investigators to essential training resources that they otherwise would not be able to attain. As the largest private supporter of hepatology research in the United States, the Foundation (along with AASLD) has awarded nearly $40 million in research and career development awards since 2000. Learn more about the AASLD Foundation at www.aasldfdn.org or Twitter @AASLDFoundation.

The annual award of $3,000 is given to the investigator presenting the most promising PSC research at The Liver Meeting®.

2016 Award
Dr. Emina Halilbasic, Medical University of Vienna, Austria. Dr. Halilbasic is working with Dr. Michael H. Trauner on the research project entitled, norUrsodeoxycholic acid (norUDCA) improves cholestasis in primary sclerosing cholangitis (PSC) independent of ursodeoycholic acid (UDCA) pre-treatment and response. 

2015 Award
Dr. Brian D. Juran, Mayo Clinic, Rochester MN received the 2015 PSC Partners funded award.  He is working with his mentor, Konstantinos N. Lazaridis, MD on the research project entitled, Patients with childhood-onset primary sclerosing cholangitis harbor rare, deleterious variants in genes involved with cholestatic syndromes and generalized risk of PSC.

2014 Award
Dr. Mohammed Nabil Quraishi, of the University of Birmingham, University of Warwick, UK received the 2014 PSC Partners funded award for Probing the microbiota in PSC: the gut adherent microbiota of PSC-IBD is distinct to that of IBD and controls.

2013 Award
The recipients of the 2013 PSC Partners funded award were Dr. Nicholas LaRusso, Dr. Steven O’Hara, Dr. James Tabibian, of the Mayo Clinic Rochester, MN, for the following research project: Cholangiocyte senescence via N-Ras activiation is a characteristic of primary sclerosing cholangitis.

2012 Award
Dr. Lina Lindstrom, of the Karolinska Institutet, Stockholm, Sweden for A Reduction in Alkaline Phosphatase Levels Is Associated To Improved Prognosis in Primary Sclerosing Cholangitis: A 14 Year Follow Up of the Scandinavian Ursodeoxycholic Acid Trial. Co-authors were Dr. Annika Bergquist, Karolinska Institutet; Dr. Kirsten Boberg, Oslo University Hospital, Oslo, Norway; Dr. Ingalill Friis-Liby, Sahlgrenska University Hospital, Goteborg, Sweden; and Dr. Rolf Hultcrantz, Karolinska Institutet. Study abstract

2011 Award
Dr. B.D. Juran, of Mayo Clinic/Rochester, for Exome sequencing in a PSC family identifies a nonsense mutation in the biliary transporter ABCB4. Co-authors were: B.S. Petersen; J.R. Hov; A. Franke; T.H. Karlsen; and K. Lazaridis.

2010 Award
J. Eaton; M. G. Silveira; K. and D. Lindor, of the Mayo Clinic/Rochester, received the PSC Partners-funded award for High Dose Ursodeoxycholic Acid is Associated with the Development of Colorectal Neoplasia in Patients with Ulcerative Colitis and Primary Sclerosing Cholangitis

2009 Award
Dr. V.S. Teaberry was the recipient of the PSC Partners-funded award. Her study is entitled: Novel Role for Hedgehog Pathway Activation in the Pathogenesis of Primary Sclerosing Cholangitis. Authors are: V.S. Teaberry; G.F.Karaca; R.P. Witek; W. Syn; A. Omenetti; Y. Jung; S.S. Choi; A. Diehl.

2008 Award
The recipients of the 2008 PSC Partners Seeking a Cure AASLD Awards were Dr. I. Tornai (2nd Department of Medicine, University of Debrecen, Debrecen, Hungary), and Dr. P. G. Blanco (Beth Israel Deaconess Medical Center, Boston, MA, USA), as described in the AASLD 2008 Annual Reportand in The Duct newsletter on pages 24 and 25, at this site:

2007 Award
The recipient of the 2007 PSC Partners Seeking a Cure AASLD Award was Dr. Thomas H. Karlsen (Medical Department and Institute of Immunology, Rikshospitalet-Radiumhospitalet Medical Center, Oslo, Norway), as described in the AASLD 2007 Annual Report and in The Duct on pages 8-9 at this site:

Grants Awarded to Specific Research Projects

STOPSC
PSC Partners has awarded $40,000 to the Studies of Primary Sclerosing Cholangitis research project, a multi-center effort (in Canada and the US) to better understand the disease, develop better ways to detect it, find out how effective current treatment may be, and conduct research on aspects of the disease.