Identification and differential expression of microRNAs associated with fat deposition in the liver of Wistar rats with nonalcoholic fatty liver disease

• A Wistar rat model of NAFLD was successfully established.
• Three biological repetitions were performed to reduce the individual differences.
• Six small RNA libraries from NAFLD and normal rat liver tissue were constructed.
• Hundred and one differentially expressed miRNAs and 68 novel miRNAs were obtained.
• This is the first report on miRNA expression profiling of NAFLD rat liver tissues.

The exact mechanism underlying hepatic steatosis in nonalcoholic fatty liver disease (NAFLD) is not clear. Clarifying the full repertoire of microRNAs (miRNAs) in NAFLD rat liver would enhance our understanding of NAFLD pathogenesis. In this study, miRNA expression levels were analyzed in liver tissue from NAFLD Wistar rats, with normal Wistar rats as negative controls. Small RNA libraries were constructed for each sample. A total of 173 conservative miRNAs and 68 potential miRNA candidates were identified. Significant differences in the expression levels of 101 conserved miRNAs were identified between the two groups. The results of GO annotation and KEGG pathway analysis revealed that some miRNAs were likely involved in the process of liver fat deposition. This study represents the first global miRNA profiling of NAFLD Wistar rat livers, and expands the miRNA repertoire for normal livers. Our findings suggest that miRNAs play important roles in liver fat deposition.