Effects of a low-fat diet on the hepatic expression of adiponectin and its receptors in rats with NAFLD

Ann Hepatol. 2015 Jan-Feb;14(1):108-17.

Abstract

Background: Non-alcoholic fatty liver disease (NAFLD) is correlated with obesity, but specific therapeutic interventions are lacking. Adiponectin is an adipokine with anti-inflammatory activity and is considered a hepatic protector. We aimed to investigate effects of a low-fat diet on the hepatic expression of adiponectin and its receptors in rats with NAFLD.

Materials and methods: Sixteen male SD rats were fed a high-fat diet for 8 weeks (HFD1 group) or 16 weeks (HFD2 group) to induce NAFLD, and these rats were compared with rats on a normal diet for 8 weeks (NC1 group) or 16 weeks (NC2 group). Another group of 8 rats was fed an HFD for 8 weeks and then switched to a low-fat diet (DIET group) until the 16th week. The expression of hepatic adiponectin and its receptors was detected by western blotting, immunohistochemistry and RT-qPCR.

Results: The NAFLD activity score (NAS) in the HFD groups increased from 3.2 ± 0.45 (8th week) to 6.2 ± 0.84 (16th week) (P < 0.001), reflecting the progression in the NAFLD histology. In contrast to the HFD2 group, the low-fat diet ameliorated the steatosis, ballooning degeneration and inflammation. Dietary intervention augmented the expression of adiponectin and its receptors, which was down-regulated in the HFD2 group.

Conclusions: The NAFLD rat model was successfully developed by feeding the animals a high-fat diet. Adiponectin may play a role in the pathogenesis of NAFLD, especially in the progression from steatosis to NASH. The low-fat diet alleviated the histological lesions associated with NAFLD by up-regulating the expression of adiponectin and its receptors.

MeSH terms

  • Adiponectin / genetics*
  • Adiponectin / metabolism
  • Alanine Transaminase / blood
  • Animals
  • Aspartate Aminotransferases / blood
  • Diet, Fat-Restricted*
  • Diet, High-Fat*
  • Liver / metabolism*
  • Liver / pathology
  • Male
  • Non-alcoholic Fatty Liver Disease / diet therapy
  • Non-alcoholic Fatty Liver Disease / genetics*
  • Non-alcoholic Fatty Liver Disease / pathology
  • RNA, Messenger / metabolism*
  • Rats
  • Receptors, Adiponectin / genetics*
  • Receptors, Adiponectin / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Adiponectin
  • Adipoq protein, rat
  • RNA, Messenger
  • Receptors, Adiponectin
  • adiponectin receptor 1, rat
  • adiponectin receptor 2, rat
  • Aspartate Aminotransferases
  • Alanine Transaminase