Prohibitin-induced, obesity-associated insulin resistance and accompanying low-grade inflammation causes NASH and HCC

Sci Rep. 2016 Mar 23:6:23608. doi: 10.1038/srep23608.

Abstract

Obesity increases the risk for nonalcoholic steatohepatitis (NASH) and hepatocarcinogenesis. However, the underlying mechanisms involved in the disease process remain unclear. Recently, we have developed a transgenic obese mouse model (Mito-Ob) by prohibitin mediated mitochondrial remodeling in adipocytes. The Mito-Ob mice develop obesity in a sex-neutral manner, but obesity-associated adipose inflammation and metabolic dysregulation in a male sex-specific manner. Here we report that with aging, the male Mito-Ob mice spontaneously develop obesity-linked NASH and hepatocellular carcinoma (HCC). In contrast, the female Mito-Ob mice maintained normal glucose and insulin levels and did not develop NASH and HCC. The anti-inflammatory peptide ghrelin was significantly upregulated in the female mice and down regulated in the male mice compared with respective control mice. In addition, a reduction in the markers of mitochondrial content and function was found in the liver of male Mito-Ob mice with NASH/HCC development. We found that ERK1/2 signaling was significantly upregulated whereas STAT3 signaling was significantly down regulated in the tumors from Mito-Ob mice. These data provide a proof-of-concept that the metabolic and inflammatory status of the adipose tissue and their interplay at the systemic and hepatic level play a central role in the pathogenesis of obesity-linked NASH and HCC.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinoma, Hepatocellular / etiology*
  • Disease Models, Animal
  • Female
  • Gene Expression Regulation, Neoplastic
  • Insulin Resistance*
  • Liver Neoplasms / etiology*
  • MAP Kinase Signaling System
  • Male
  • Mice
  • Mice, Obese
  • Non-alcoholic Fatty Liver Disease / etiology*
  • Obesity / genetics
  • Obesity / immunology*
  • Obesity / metabolism
  • Prohibitins
  • Repressor Proteins / deficiency*
  • STAT3 Transcription Factor / metabolism
  • Sex Characteristics

Substances

  • Prohibitins
  • Repressor Proteins
  • STAT3 Transcription Factor
  • Stat3 protein, mouse