This is an author version of the contribution published on:
Questa è la versione dell’autore dell’opera:
[Journal of Hepatology, Vol. 66, 2017]
ovvero [O. Govaere1, S.J. Cockell2,M. Vacca3,M. Allison4, S. Petta5, J. Boursier6, E.
Bugianesi7, R. Darlay8, H.J. Cordell8, F. Marra9, P. Bedossa10, D. Tiniakos1, A.
Vidal-Puig3, K. Clément11, J.M. Schattenberg12, V. Ratziu11, Q.M. Anstee1, A.K. Daly1 and
On behalf of the EPoS Consortium.,
Vol.66, 2017, pagg.S50]
The definitive version is available at:
La versione definitiva è disponibile alla URL:
[http://www.journal-of-hepatology.eu/action/doSearch?
searchType=quick&searchText=international+liver+congress&occurrences=all&journ
alCode=jhepat&searchScope=fullSite]
High-throughput RNA sequencing unravels pathways associated with the progression of non-alcoholic liver disease
O. Govaere1, S.J. Cockell2,M. Vacca3,M. Allison4, S. Petta5, J. Boursier6, E. Bugianesi7, R. Darlay8, H.J. Cordell8, F. Marra9, P. Bedossa10, D. Tiniakos1, A. Vidal-Puig3, K. Clément11, J.M. Schattenberg12, V. Ratziu11, Q.M. Anstee1, A.K. Daly1 and On behalf of the EPoS Consortium.
1Institute of Cellular Medicine; 2Bioinformatics Support Unit, Newcastle University, Newcastle upon Tyne; 3University of Cambridge Metabolic Research Laboratories,Wellcome-MRC Institute of Metabolic Science, Addenbrooke’s Hospital; 4Liver Unit, Department of Medicine, Cambridge Biomedical Research Centre, Cambridge University NHS Foundation Trust, Cambridge, United Kingdom; 5Sezione di Gastroenterologia, Dipartimento Biomedico di Medicina Interna e
Specialistica, Università di Palermo, Palermo, Italy; 6CHU d’Angers Service
d’Hépato-Gastroentérologie, Univ LUNAM, Angers, France; 7Department of Medical Sciences, Division of Gastro-Hepatology, A.O.Città della Salute e della Scienza di Torino, University of Turin, Turin, Italy; 8Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom; 9Dipartimento di Medicina Sperimentale e Clinica, University of Florence, Florence, Italy; 10Assistance Publique-Hôpitaux de Paris, Hôpital Beaujon, University Paris-Diderot; 11Institute of Cardiometabolism and Nutrition, Pitié-Salpêtrière Hospital, Paris, France; 12Department of Medicine, University Hospital, Mainz, Germany E-mail:
olivier.govaere@ncl.ac.uk
Background and Aims: Non-alcoholic fatty liver disease (NAFLD) is classified histologically
according to the level of progression and hence disease severity, with a wide spectrum ranging from “simple” steatosis to non-alcoholic steatohepatitis, which may eventually lead to cirrhosis. The mechanisms causing steatosis and promoting disease progression are still poorly understood. This study aims to better understand the pathogenesis of NAFLD by unraveling underlying pathways using a high-throughput RNA sequencing approach.
Methods: 114 snap frozen needle biopsies were included in this study. 102 samples were obtained
from patients diagnosed with NAFLD, 12 samples with normal liver histology were obtained from patients undergoing bariatric surgery. Alternate diagnoses/aetiologies were excluded, including increased alcohol intake. The histological semi-quantitative SAF scorewas used to determine the degree of steatosis (S0–3), NAFLD activity (A0–4) and stage of fibrosis (F0–4). Peripheral blood DNA was available from all samples and was analysed in a genome-wide association study. RNAwas isolated from each biopsy sample and processed for RNA sequencing using an Illumina NextSeq 500 system. Differentially expressed genes were analysed using Qiagen′s Ingenuity Pathway Analysis software. This studywas approved by the relevant ethical committees and informed consent was obtained from each patient.
Results: 805 genes were differentially expressed comparing steatosis with normal liver controls.
Steatosis showed an increase in genes related to cholesterol biosynthesis (e.g. FDFT1, NSDHL, DHCR7, TM7SF2, CYP51A1), LXR/RXR activation (e.g. SCD, SREBF1, CYP7A1, ACACA) and fatty acid metabolism (e.g. PNPLA3, FASN, ELOVL5), while there was a decrease in insulin growth factor 1-signaling (e.g. IRS2, IGFBP1, IGFBP2, FOS) and immune response (e.g. IL-6, CXCL2, CCL2). Comparing steatohepatitis with the normal liver controls revealed 1,146 differentially expressed genes, relevant to a number of pathways including p53 (e.g. TP53I3, TIGAR, CCND1) and fibrosis (e.g. PDGFA, COL10A1, LAMB3, MMP1) together with an increase in hepatic progenitor cell-related genes (e.g. EPCAM, CD24, KRT23, SOX9). While therewas a significant decrease in IL-6, IL-10 and CXCL2 expression, a strong increase in CCL24 expression was seen.
Conclusions: Our results show that progression from steatosis to steatohepatitis in NAFLD
