Fig. 1

Metabolic cross-talk and apoptosis in the progression of obesity and NAFLD/NASH. In obesity, excessive fat accumulation results in overexpansion of adipose tissue, resulting in adipocyte cell death which promotes inflammatory macrophage infiltration and adipose/metabolic dysfunction. Increases in circulating FFA from obese adipose tissue and/or from diet contribute to the excessive accumulation of lipids in the liver and development of NAFLD. Release of inflammatory cytokines from adipose tissue further contributes to liver inflammation, metabolic dysfunction and hepatocyte cell death. Progression of NAFLD to NASH to more severe NASH involves marked increases in hepatocyte apoptosis, resulting in hepatic stellate activation, collagen deposition, scarring and fibrosis. Abbreviations: FFA free fatty acids, HCC hepatocellular carcinoma, HSC hepatic stellate cell, IL interleukin, NAFLD nonalcoholic fatty liver disease, NASH nonalcoholic steatohepatitis, TNF tumour necrosis factor