Exercise Improves Nonalcoholic Fatty Liver Disease in T2DM Mice by Inhibiting Ferroptosis Through p38 MAPK Signaling Pathway
Objective To explore the mechanism of treadmill exercise against type 2 diabetes mellitus(T2DM)with non-alcoholic fatty liver disease(NAFLD)based on the regulator effects of exercise on ferroptosis.Methods Eight 8-week-old male m/m mice were used as control group(Con,n=8),and db/db mice of the matched age were randomly divided into T2DM model group(db/db,n=8),exercise group(db+Exe,n=8),p38 mitogen-activated protein kinase(MAPK)inhibitor group(db+SB203580,n=8)and exercise combined with p38 MAPK inhibitor group(db+Exe+SB203580,n=8).After one-week adaptive feeding,the mice in the db+Exe group and db+Exe+SB203580 group underwent moderate intensity treadmill exercise for 40 min/d,5 d/week lasting 8 weeks.The db+SB203580 group and db+Exe+SB203580 group were treated with SB203580(a specific inhibitor of p38 MAPK)with a dose of 5 mg/kg,5 d/week for 8 weeks.And the exercise intervention was performed 2 h later after the intraperitoneal injection of SB203580.The body weight and fasting blood glucose of mice were measured regularly every week during the experiment.After 24 h of the last intervention,the mice were weighted,the liver tissues were taken,weighted and the liver index was calculated.The pathological changes of liver were determined by Oil Red O and hematoxylin-eosin(HE)staining.The levels of blood lipids,liver function,Fe2+and oxidative stress markers of liver were measured by enzyme linked immunosorbent assay(ELISA).The related mRNA expression levels of lipogenesis and inflammation were evaluated by quantitative reverse transcriptase-mediated PCR(qRT-PCR).The related protein expression levels of lipogenesis and ferroptosis in liver were determined by immunohistochemical(IHC)staining and Western blot.Results The body weight,fasting blood glucose,liver index,blood lipid and transaminase levels in the db/db group were significantly increased compared with the Con group.HE and Oil Red O staining showed severe lipid accumulation and ballooning change in the liver of db/db mice.Biochemical tests showed that Fe2+and MDA level of liver constitution homogenate increased,while GSH level decreased significantly.The results of qRT-PCR showed that the mRNA levels of MCP-1,IL-6,SREBF1 and ACC1 in liver tissue of db/db mice were all significantly increased.Western blot results showed that the expression levels of SREBF1,ACC1 increased,ferroptosis relative proteins were significantly decreased.The 8 weeks of exercise significantly reduced the rise in body weight,blood glucose,liver index and blood lipid levels in db/db mice.Exercise intervention also alleviated hepatic steatosis and reduced the expression levels of Fe2+,MDA,MCP-1,IL-6,ACC1 and SREBF1,upregulated the expression levels of GSH,NRF2,HO-1,SLC7A11 and GPX4 in liver tissue of db/db mice.The intervention of exercise combined with SB203580 significantly down-regulated the mRNA expression levels of ACC1,MCP-1,IL-6,reduced the levels of Fe2+and MDA,and up-regulated the level of GSH in db/db mice.Compared with the db+Exe group,the expression of Fe2+,MDA,MCP-1,and SREBF1 in the liver of the db+Exe+SB203580 group mice significantly increased,while the expression level of GSH and expression levels of ferroptosis relative proteins also significantly decreased.In addition,compared with db+SB203580 group,the iron accumulation and lipid peroxidation in the liver of db+Exe+SB203580 group were significantly improved.Conclusion The 8-week treadmill exercise can effectively alleviate liver injury and steatosis,and its mechanism may be related to the inhibition of hepatocyte ferroptosis through p38 MAPK signal.
万方数据
维普
