Integrated miR-mRNA Network Underlying Hepatic Fat Accumulation in Humans

Abstract

Background: An integrate miRs and mRNAs analysis in the development of Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH) is lacking. We aimed to identify miRs as well as the miR-mRNA regulatory network involved in hepatic fat accumulation and human NAFLD. Materials and Methods: Hepatic fat content (HFC) was measured, and liver histology was characterized for 73 liver tissue samples. MicroRNAs and mRNAs significantly associated with HFC were identified based on genome-wide mRNA and miR expression profiling data. These miRs and mRNAs were further used to build miR-mRNA association networks in NAFLD and normal samples based on the potential miR-mRNA targeting, as well as to conduct a pathway enrichment analysis. Results: We identified 62 miRs significantly correlated with HFC (p<0.05), with miR-518b and miR-19b demonstrated to be the most significant positive and negative correlation with HFC, respectively (p<0.008 for both). Many miRs that were previously associated with NAFLD/NASH were also observed. Integrated network analysis indicated that a few miRs-30b*, 616, 17*, 129-5p, 204, and 20a controlled >80% of HFC-associated mRNAs in this network, and the regulation network was significantly rewired from normal to NAFLD. Pathway analyses revealed that inflammation pathways mediated by chemokine and cytokine signaling, Wnt signaling, lntegrin signaling and Natural killer cell mediated cytotoxicity were enriched (p<0.05) in hepatic fat accumulation.