title: CCL5 mRNA is a marker for early fibrosis in chronic hepatitis C and is regulated by interferon-α therapy and toll-like receptor 3 signalling.
abstract: Mechanisms causing liver fibrosis during chronic hepatitis C virus infection (cHCV) are not sufficiently understood. This study was aimed to identify biomarkers for early fibrosis (EF) and to investigate their potential role in cHCV-related fibrogenesis. To this end, peripheral whole blood (PB) samples from 36 patients with cHCV recruited from two independent cohorts were subjected to microarray analysis 12 h before initiation of peginterferon-alpha (Peg-IFN-α) and ribavirin therapy. Liver biopsies were evaluated using the Batts-Ludwig staging (BL-S) classification system for fibrosis. We showed that gene expression profiles (N = 8) distinguished between EF (BL-S: 0,1) and late fibrosis (LF; BL-S: 2,3,4) with 88.9% accuracy. Fibrosis-related functional annotations for chemokine-'C-C-motif'' ligand 5 (CCL5) provided foundation for focused investigation, and qRT-PCR confirmed that CCL5 mRNA levels (PB) reliably discriminate EF from LF (accuracy: 86.7%). Positive correlations (P < 0.05) with CCL5 mRNA levels and EF discovered gene expression profiles (PB) reflecting stable expression of IFN-α receptor 1, negative regulation of the MyD88-dependent toll-like receptor (TLR) pathway and decreased expression of TLR3 in vivo. Remarkably, Peg-IFN-α suppressed CCL5 mRNA levels (PB) in EF in vivo. These findings along with results from parallel in vitro investigation into the effect of IFN-α or poly I:C (TLR3-agonist) on CCL5 gene expression in hepatic stellate cells (HSC) attest to the multi-site involvement of these pathways in regulating fibrogenesis. In conclusion, we identified novel, reliable biomarkers for EF and exposed functional properties of the molecular network regulating CCL5 biosynthesis in peripheral or hepatic cell types with key roles in cHCV-related liver and/or immune pathogenesis.
authors.affiliation: Dept. of Gastroenterology and Hepatology, University Hospital of Essen, Essen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Katsounas
authors.forename: M
authors.initials: M
authors.lastname: Trippler
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.forename: M
authors.initials: M
authors.lastname: Polis
authors.forename: R A
authors.initials: RA
authors.lastname: Lempicki
authors.forename: S
authors.initials: S
authors.lastname: Kottilil
authors.forename: G
authors.initials: G
authors.lastname: Gerken
authors.forename: J F
authors.initials: JF
authors.lastname: Schlaak
mesh_terms: D000998:Antiviral Agents / Q000008:administration & dosage / Q000276:immunology; D015415:Biomarkers; D001706:Biopsy; D018946:Chemokine CCL5 / Q000096:biosynthesis*; D020869:Gene Expression Profiling; D019698:Hepatitis C, Chronic / Q000150:complications* / Q000188:drug therapy; D006801:Humans; D007155:Immunologic Factors / Q000008:administration & dosage / Q000276:immunology; D016898:Interferon-alpha / Q000008:administration & dosage / Q000276:immunology*; D007962:Leukocytes / Q000276:immunology; D008099:Liver / Q000473:pathology; D008103:Liver Cirrhosis / Q000175:diagnosis* / Q000473:pathology; D046228:Microarray Analysis; D012333:RNA, Messenger / Q000096:biosynthesis*; D060888:Real-Time Polymerase Chain Reaction; D012254:Ribavirin / Q000008:administration & dosage; D015398:Signal Transduction; D051196:Toll-Like Receptor 3 / Q000276:immunology*
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers; C483024:CCL5 protein, human; D018946:Chemokine CCL5; D007155:Immunologic Factors; D016898:Interferon-alpha; D012333:RNA, Messenger; C495344:TLR3 protein, human; D051196:Toll-Like Receptor 3; D012254:Ribavirin