Concurrent exercise improves insulin resistance and nonalcoholic fatty liver disease by upregulating PPAR-\u03b3 and genes involved in the beta-oxidation of fatty acids in ApoE-KO mice fed a high-fat diet

Abstract

ObjectiveTo emphasize the mechanism of concurrent exercise effect on lipid disorders in insulin resistance (IR) and nonalcoholic fatty liver disease (NAFLD).Materials and methodsTwenty male ApoE knockout mice were randomly divided into two groups: HFD group (n = 10) fed a high fat diet, and HFDE group (n = 10) with high-fat diet intervention for 12 weeks and swimming exercise. Other ten healthy male C57BL/6 J mice were fed a normal diet, and included as control group. Retro-orbital blood samples were collected for biochemical analysis. Oil red O staining of liver tissues was performed to confirm the exercise effect. Western blotting was performed to evaluate the expressions of PPAR-γ, CPT-1, MCAD.ResultsThe levels of TG, TC, LDL, FFA, FIN, FPG and Homa-IRI in the HFD group were significantly higher than ND group, while these were markedly decreased in the HFDE group compared with HFD group. The Oil Red O staining of liver samples further confirmed the exercise effect on the change of lipid deposition in the liver. Western blotting showed increased expressions of PPAR-γ, CPT-1, MCAD induced by high fat diet were significantly downregulated by exercise.ConclusionA concurrent 12-week exercise protocol alleviated the lipid metabolism disorders of IR and NAFLD, probably via PPAR-γ/CPT-1/MCAD signaling.