Abstract:

Objective ·To detect the differences in m⁶A methylation modification and gene expression of liver tissue mRNA in high-fat diet-induced mouse models of non-alcoholic fatty liver disease (NAFLD) using microarray technology. Methods ·The NAFLD models were established in 6-8 weeks old male C57BL/6J mice fed with high-fat chow for 16 weeks (high-fat group, n=10). The basal group (n=10) was given 10% fat diet. Hematoxylin-eosin (H-E) staining was used to assess the histopathological changes in liver tissue and to determine the success of the NAFLD models. The changes of mRNA m⁶A methylation and expression levels in the liver tissues of the two groups were detected by using methylated RNA immunoprecipitation (MeRIP) and microarray expression profiling. Results ·The livers of the mice in the basal group were bright red with few fat deposits, while the livers of the mice in the high-fat group were yellowish with diffuse infiltration and fusion of lipid droplets in the hepatocytes by H-E staining, suggesting that the high-fat diet-induced NAFLD models were successfully constructed. The results of the MeRIP-microarray showed that the m⁶A methylation levels of 320 genes in the livers of mice in the high-fat group were significantly altered compared with those in the basal group (P<0.05 and fold change>1.5), of which 108 genes were up-regulated and 212 genes were down-regulated. Genes with significant differences in m⁶A methylation levels between the two groups were intersected with those with differentially expressed mRNAs, and 163 genes were found to have significant differences in both m⁶A methylation level and mRNA expression level. Conclusion ·The change in m⁶A modification of liver tissue mRNA in the high-fat diet-induced mouse models of NAFLD is significant and the change is associated with the gene expression of mRNA.

Key words: non-alcoholic fatty liver disease (NAFLD), m⁶A methylation modification, mRNA, epitranscriptomics