Pharmacologic Inhibition of Epidermal Growth Factor Receptor Suppresses Non-alcoholic Fatty Liver Disease in Murine Fast-food Diet Model

EGFR is a critical regulator of hepatocyte proliferation and liver regeneration. Our recent work indicated EGFR can also regulate lipid metabolism during liver regeneration after partial-hepatectomy. Based on these findings, we investigated role of EGFR in a mouse model of NAFLD utilizing a pharmacological inhibition strategy. C57BL6/J mice were fed chow-diet, or fast-food diet with/without EGFR inhibitor (Canertinib) for 2-months. EGFR inhibition completely prevented development of steatosis and liver injury in this model. In order to study if EGFR inhibition can reverse NAFLD progression, mice were fed fast-food diet for 5-months, with/without Canertinib-treatment for the last 5-weeks of the study. EGFR-inhibition remarkably decreased steatosis, liver injury, fibrosis and improved glucose tolerance. Microarray analysis revealed ~40% of genes altered by fast-food diet were differentially expressed after EGFR-inhibition, and thus, are potentially regulated by EGFR. Several genes and enzymes related to lipid metabolism (particularly fatty-acid synthesis and lipolysis), which were disrupted by fast-food diet, were found to be modulated by EGFR. Several crucial transcription factors that play a central role in regulating these lipid metabolism genes during NAFLD, including PPARγ, SREBF1, ChREBP and HNF4α, were also found to be modulated by EGFR. In fact, ChIP-analysis revealed PPARγ binding to several crucial lipid metabolisms genes (Fasn, Scd1 and Plin2) was drastically reduced by EGFR inhibition. Further upstream, EGFR-inhibition suppressed AKT signaling, which is known to control these transcription factors, including PPARγ and SREBF1, in NAFLD models. Lastly, the effect of EGFR in FFD-induced fatty-liver phenotype was not shared by receptor-tyrosine-kinase MET, as investigated using MET-KO mice. In-conclusion, our study revealed a role of EGFR in NAFLD and the potential of EGFR-inhibition as a treatment strategy for NAFLD. We used microarrays to detail the global programme of gene expression in liver of C57BL6/J mice fed fast-food diet mice treated with EGFR inhibitor (canertinib) For the two months study, 6-8 weeks old male C57BL6/J mice were fed ad libitum (i) chow diet, (ii) fast-food diet [western diet - high saturated fats (21% by weight; 42% kcal from fat), high cholesterol (0.2%) and high carbohydrates (sucrose: 34% by weight) in diet (TD.88137, Teklad) - along with high-fructose-glucose solution (d-glucose: 18.9g/L and d-fructose: 23.1g/L) in drinking water] or (iii) Canertinib (a highly potent and selective EGFR inhibitor/ EGFRi) added in the same fast-food diet for 2-months. Canertinib was administered to mice in diet for estimated dose of 80 mg/kg/day. For the five months study, 6-8 weeks old male C57BL6/J mice were fed ad libitum (i) chow diet, (ii) and (iii) fast-food diet for 5-months. Group (ii) and (iii) were administered vehicle (PBS) and Canertinib (80mg/kg; i.p.), respectively, 5 days/week for the last 5-weeks of 5-months period. Microarray analysis was performed on RNAs isolated from pooled liver samples (n=3-4) from the chow, FFD and FFD + EGFRi group for both 2 and 5 months studies, using the GeneChip® Mouse Genome 430 2.0 Array Set 430 (Affymetrix, Santa Clara, CA).