Western Diet-Induced Nonalcoholic Fatty Liver Disease Mice Mimic the Key Transcriptomic Signatures Observed in Humans

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease characterized by the accumulation of fat in the liver in the absence of excessive alcohol consumption or a secondary cause of hepatic steatosis. The prevalence of NAFLD is increasing worldwide and its management has become a public health concern. Animal models are traditionally used to elucidate disease mechanisms and identify potential drug targets; however, their translational aspects in human diseases have not been fully established. This study aimed to clarify the utility of animal models for translational research by assessing their relevance to human diseases using gene expression analysis. Weighted gene co-expression network analysis of liver tissues from Western diet (WD)-induced NAFLD mice was performed to identify the modules associated with disease progression. Moreover, the similarity of the gene co-expression network across species was evaluated using module preservation analysis. Nineteen disease-associated modules were identified. The brown module was positively associated with disease severity, and functional analyses indicated that it may be involved in inflammatory responses in immune cells. Moreover, the gene co- expression network of the brown module was highly preserved in human NAFLD liver gene expression datasets. These results indicate that WD-induced NAFLD mice have similar gene co- expression networks (especially genes associated with inflammatory responses) to humans and are thought to be a useful experimental tool for preclinical research on NAFLD.