HCV and the hepatic lipid pathway as a potential treatment target

Atherosclerosis has been described as a liver disease of the heart. The liver is the central regulatory organ of lipid pathways but since dyslipidaemias are major contributors to cardiovascular disease and type 2 diabetes rather than liver disease, research in this area has not been a major focus for hepatologists. Virus-host interaction is a continuous co-evolutionary process involving the host immune system and viral escape mechanisms. One of the strategies HCV has adopted to escape immune clearance and establish persistent infection is to make use of hepatic lipid pathways. This review aims to: update the hepatologist on lipid metabolism; review the evidence that HCV exploits hepatic lipid pathways to its advantage; discuss approaches to targeting host lipid pathways as adjunctive therapy

A Collaborative Clearinghouse for Data Management Training and Education Resources

Objective: The main objectives of this breakout session are for the Data Management Training (DMT) Clearinghouse team to: 1) introduce the Clearinghouse and its current design and implementation, 2) solicit submissions to its learning resource inventory, and 3) collect feedback upon its web interface and future development. Features of the Clearinghouse that will be demonstrated include how to search and browse its inventory as well as submit a learning resource to the Clearinghouse using the LRMI (Learning Resource Metadata Initiative) metadata format. The team will also share the roadmap for the Clearinghouse’s upcoming features. In order to provide feedback regarding the Clearinghouse’s usability, the team will invite the session attendees to test the Clearinghouse’s services and will encourage comments to guide its future development. Setting/Participants/Resources: Since the DMT Clearinghouse is entirely accessible via the web, in order to demonstrate the Clearinghouse successfully, a reliable (and preferably free of charge) internet connection, and an overhead projecting capability will need to be available to the presenter. It would also be very useful for the attendees of the session to have access to the same internet connection, so that if they desire, the attendees can follow along with the steps of the demonstration, and contribute to the Clearinghouse inventory. The main presenter will plan to bring her own laptop with built-in standard HDMI and USB ports. As a result, it will be helpful if a HDMI or USB cable could also be provided for the presenter to connect her laptop to the projecting equipment. Method: Many research organizations, government agencies, and academic institutions have been developing excellent learning resources in order to support and meet the needs for data management training. However, these learning resources are often hosted on various websites and spread across various scientific domains. Consequently, these resources can be difficult to locate, especially by those who are not already familiar with the creators/authors. This is a barrier to the use and reuse of these resources, and can have significant impact on the promotion and propagation of best practices for data management. To address this need within the Earth sciences, the U.S. Geological Survey’s (USGS) Community for Data Integration (CDI), the Federation of Earth Science Information Partners (ESIP), and the Data Observation Network for Earth (DataONE) have collaborated to create a web-based Clearinghouse1 for collecting data management learning resources that are focused on the Earth sciences. The initial seed funding for the effort was provided by a grant received from the USGS CDI earlier in 2016, and ESIP’s Drupal site provided the hosting infrastructure for the Clearinghouse. Members from the USGS, DataONE, ESIP’s Data Stewardship Committee and its Data Management Training Working Group, Knowledge Motifs LLC, as well as Blue Dot Lab met regularly between April and October, 2016 in order to discuss, create, and implement the content structure and infrastructure components necessary to build the current revision of the Clearinghouse. 1. http://dmtclearinghouse.esipfed.org Results: As a registry of information about the educational resources on topics related to research data management (initially focused on Earth sciences), the Clearinghouse serves as a centralized location for searching or browsing an inventory of these learning resources. Currently, the Clearinghouse offers search and browse functionality that is open to all, and submission of information about educational resources by login with a free ESIP account. To assist with discoverability, the learning resources are described using Learning Resource Metadata Initiative (LRMI) schema. Additionally, the resources may be associated with the steps of data and research life cycles, such as the USGS CDI’s Science Support Framework2 and DataONE’s Data Life Cycle3. Leveraging the team’s collective experience in creating, presenting and distributing data management learning resources, the Clearinghouse included the learning resources from USGS, ESIP, and DataONE as its initial inventory, but is expanding to resources from NASA and others. Crowdsourcing is currently the main mechanism for sustaining the Clearinghouse. Going forward, in addition to the built-in workflow to allow anyone from the public to submit descriptive information about the data management learning resources that s/he wishes to share, future capabilities will be added to enable contributions to review, edit, and rank the submissions, as desired. 2. https://my.usgs.gov/confluence/display/cdi/CDI+Science+Support+Framework3. https://www.dataone.org/data-life-cycle Discussion/Conclusion: The DMT Clearinghouse team was successful in completing the initial development phase as scheduled for the first six months of its funding, including some informal usability testing of the interface. The team aims to continue to develop and enhance the Clearinghouse’s capabilities, including the evaluation of its usability, through collaboration with additional communities, and if feasible, adding the capability for bulk-loading of learning resources. Being able to present the Clearinghouse at the eScience Symposium would not only allow those who are involved with or would like to learn about data management to leverage the Clearinghouse’s resources, but also connect those who would like to contribute to the project with the Clearinghouse team. Ultimately, the Clearinghouse is designed so that the resources from its inventory could be used in a variety of data management training and education environments. By exposing the Clearinghouse to diverse users and communities, the Clearinghouse team can better assess how the Clearinghouse can be updated and what technological enhancements to pursue in the future in order to improve our support of research data management training needs

Identification of improved IL28B SNPs and haplotypes for prediction of drug response in treatment of hepatitis C using massively parallel sequencing in a cross-sectional European cohort

BACKGROUND: The hepatitis C virus (HCV) infects nearly 3% of the World's population, causing severe liver disease in many. Standard of care therapy is currently pegylated interferon alpha and ribavirin (PegIFN/R), which is effective in less than half of those infected with the most common viral genotype. Two IL28B single nucleotide polymorphisms (SNPs), rs8099917 and rs12979860, predict response to (PegIFN/R) therapy in treatment of HCV infection. These SNPs were identified in genome wide analyses using Illumina genotyping chips. In people of European ancestry, there are 6 common (more than 1%) haplotypes for IL28B, one tagged by the rs8099917 minor allele, four tagged by rs12979860. METHODS: We used massively parallel sequencing of the IL28B and IL28A gene regions generated by polymerase chain reaction (PCR) from pooled DNA samples from 100 responders and 99 non-responders to therapy, to identify common variants. Variants that had high odds ratios and were validated were then genotyped in a cohort of 905 responders and non-responders. Their predictive power was assessed, alone and in combination with HLA-C. RESULTS: Only SNPs in the IL28B linkage disequilibrium block predicted drug response. Eighteen SNPs were identified with evidence for association with drug response, and with a high degree of confidence in the sequence call. We found that two SNPs, rs4803221 (homozygote minor allele positive predictive value (PPV) of 77%) and rs7248668 (PPV 78%), predicted failure to respond better than the current best, rs8099917 (PPV 73%) and rs12979860 (PPV 68%) in this cross-sectional cohort. The best SNPs tagged a single common haplotype, haplotype 2. Genotypes predicted lack of response better than alleles. However, combination of IL28B haplotype 2 carrier status with the HLA-C C2C2 genotype, which has previously been reported to improve prediction in combination with IL28B, provides the highest PPV (80%). The haplotypes present alternative putative transcription factor binding and methylation sites. CONCLUSIONS: Massively parallel sequencing allowed identification and comparison of the best common SNPs for identifying treatment failure in therapy for HCV. SNPs tagging a single haplotype have the highest PPV, especially in combination with HLA-C. The functional basis for the association may be due to altered regulation of the gene. These approaches have utility in improving diagnostic testing and identifying causal haplotypes or SNPs

Infection with the hepatitis C virus causes viral genotype-specific differences in cholesterol metabolism and hepatic steatosis

Lipids play essential roles in the hepatitis C virus (HCV) life cycle and patients with chronic HCV infection display disordered lipid metabolism which resolves following successful anti-viral therapy. It has been proposed that HCV genotype 3 (HCV-G3) infection is an independent risk factor for hepatocellular carcinoma and evidence suggests lipogenic proteins are involved in hepatocarcinogenesis. We aimed to characterise variation in host lipid metabolism between participants chronically infected with HCV genotype 1 (HCV-G1) and HCV-G3 to identify likely genotype-specific differences in lipid metabolism. We combined several lipidomic approaches: analysis was performed between participants infected with HCV-G1 and HCV-G3, both in the fasting and non-fasting states, and after sustained virological response (SVR) to treatment. Sera were obtained from 112 fasting patients (25% with cirrhosis). Serum lipids were measured using standard enzymatic methods. Lathosterol and desmosterol were measured by gas-chromatography mass spectrometry (MS). For further metabolic insight on lipid metabolism, ultra-performance liquid chromatography MS was performed on all samples. A subgroup of 13 participants had whole body fat distribution determined using in vivo magnetic resonance imaging and spectroscopy. A second cohort of (non-fasting) sera were obtained from HCV Research UK for comparative analyses: 150 treatment naïve patients and 100 non-viraemic patients post-SVR. HCV-G3 patients had significantly decreased serum apoB, non-HDL cholesterol concentrations, and more hepatic steatosis than those with HCV-G1. HCV-G3 patients also had significantly decreased serum levels of lathosterol, without significant reductions in desmosterol. Lipidomic analysis showed lipid species associated with reverse cholesterol transport pathway in HCV-G3. We demonstrated that compared to HCV-G1, HCV-G3 infection is characterised by low LDL cholesterol levels, with preferential suppression of cholesterol synthesis via lathosterol, associated with increasing hepatic steatosis. The genotype-specific lipid disturbances may shed light on genotypic variations in liver disease progression and promotion of hepatocellular cancer in HCV-G3

MBOAT7 rs641738 increases risk of liver inflammation and transition to fibrosis in chronic hepatitis C

Cirrhosis likely shares common pathophysiological pathways despite arising from a variety of liver diseases. A recent GWAS identified rs641738, a polymorphism in the MBOAT7 locus, as being associated with the development of alcoholic cirrhosis. Here we explore the role of this variant on liver inflammation and fibrosis in two cohorts of patients with chronic hepatitis C. In 2,051 patients, rs641738 associated with severe hepatic inflammation and increased risk of fibrosis, as well as fast fibrosis progression. At functional level, rs641738 associated with MBOAT7 transcript and protein levels in liver and blood, and with serum inflammatory, oxidative stress and macrophage activation markers. MBOAT7 was expressed in immune cell subsets, implying a role in hepatic inflammation. We conclude that the MBOAT7 rs641738 polymorphism is a novel risk variant for liver inflammation in hepatitis C, and thereby for liver fibrosis

IFN-λ3, not IFN-λ4, likely mediates IFNL3–IFNL4 haplotype–dependent hepatic inflammation and fibrosis

The International Liver Disease Genetics Consortium (ILDGC).Genetic variation in the IFNL3–IFNL4 (interferon-λ3–interferon-λ4) region is associated with hepatic inflammation and fibrosis1,2,3,4. Whether IFN-λ3 or IFN-λ4 protein drives this association is not known. We demonstrate that hepatic inflammation, fibrosis stage, fibrosis progression rate, hepatic infiltration of immune cells, IFN-λ3 expression, and serum sCD163 levels (a marker of activated macrophages) are greater in individuals with the IFNL3–IFNL4 risk haplotype that does not produce IFN-λ4, but produces IFN-λ3. No difference in these features was observed according to genotype at rs117648444, which encodes a substitution at position 70 of the IFN-λ4 protein and reduces IFN-λ4 activity, or between patients encoding functionally defective IFN-λ4 (IFN-λ4–Ser70) and those encoding fully active IFN-λ4–Pro70. The two proposed functional variants (rs368234815 and rs4803217)5,6 were not superior to the discovery SNP rs12979860 with respect to liver inflammation or fibrosis phenotype. IFN-λ3 rather than IFN-λ4 likely mediates IFNL3–IFNL4 haplotype–dependent hepatic inflammation and fibrosis.M.E., M.D., and J.G. are supported by the Robert W. Storr Bequest to the Sydney Medical Foundation, University of Sydney, and by a National Health and Medical Research Council of Australia (NHMRC) Program Grant (1053206) and NHMRC Project Grants (APP1107178 and APP1108422). G.D. is supported by an NHMRC Fellowship (1028432)

IL28B, HLA-C, and KIR Variants Additively Predict Response to Therapy in Chronic Hepatitis C Virus Infection in a European Cohort: A Cross-Sectional Study

Vijayaprakash Suppiah and colleagues show that genotyping hepatitis C patients for the IL28B, HLA-C, and KIR genes improves the ability to predict whether or not patients will respond to antiviral treatment