Epigenetic regulation of NAFLD: A preclinical study

Background & objectives Non-alcoholic fatty liver disease (NAFLD) is considered as the most prevalent chronic metabolic disease, characterised by steatosis, inflammation, and metabolic dysfunctions with impaired functions of liver enzymes. The fat mass and obesity-associated gene (FTO) plays an important role in fat accumulation in hepatocytes. We investigated how FTO regulated the expression of its target genes via m6A modification leading to the pathophysiology of NAFLD. Methods A NAFLD mouse model was developed by feeding C57Bl/6 male mice on high-fat, high-carbohydrate (HFHC) diet supplemented with fructose and sucrose up to 24 wk. Changes in the liver histology were examined in serial sections by microscopy and immunohistochemistry, the serum parameters were monitored by bioanalyser and ELISA. Expression of hepatic murine FTO (mFTO) and metabolic gene transcripts were quantified by qPCR and mRNA sequencing. mFTO protein expression was analysed by immunohistochemistry and western blotting. Results The NAFLD mouse model developed steatosis, inflammation, and fibrosis at 19-24 wk, along with elevated liver enzyme levels, altered lipid profiles, and increased mFTO expression. Transcriptomic analysis identified differentially expressed genes and pathways associated with NAFLD progression. Pharmacological inhibition of mFTO by entacapone restored m6A marks on gene transcripts and reversed the NAFLD phenotype. Interpretation & conclusions Gene expression profiling identified key metabolic pathways and molecular targets associated with NAFLD progression. It underscored the role of mFTO in altering the m6A methylation landscape essential for establishing NAFLD and highlighted its therapeutic potential for NAFLD-associated morbidities.