Effects Of Exercise Combined With Corn Peptide Intervention On Thl7/Treg Balance In Liver Of High Fat Diet-induced Obese Rats

Objective: To understand the molecular mechanisms for exercise combined withcorn-peptide intervention-induced improvement in obese fatty liver from“enterohepatic axis” angle, we investigated effects of exercise combined withcorn-peptide intervention on Th17/Treg balance in liver and intestinal permeabilityof obese rats.Material and Methods:150SD male rats, weight180-200g,15rats were randomlychosen as control group, the other135rats were given high-fat diet to induce obesityfor eight weeks. After eight weeks, the obese rats were randomly divided into obesecontrol group(OC), corn peptide group(CP), exercise group(E), and exerciseconbined with corn peptide group(EC), eight rats in each group. The rats in CP groupand EC group were given corn peptide diet, the other groups were given normal diet,the rats in E group and EC group were given aerobic exercise intervention. Fourweeks after intervention,the rats were sacrificed,blood and tissues were collected.The expression of RORγt and FoxP3in liver were detected using Western blot, Oilred staining was used to detect lipid deposition in liver, Spectrophotometrictechnique was used to detect intestinal permeability indicators diamine oxidase(DAO) activity in serum, the serum Endotoxin and D-lactic acid levels weredetermined using enzyme-linked immunosorbent assay (ELISA). Pearson correlationcoefficient analysis was used to analyse correlations between intestinal permeabilityindicators(DAO, D-lactate) and Endotoxin, liver Th17/Treg cells.Results:(1) Compared with control group, High fat diet induced significant increasein body weight, hepatic lipid deposition increase and significant decrease in liverFoxP3expression, while visceral fat content and liver RORγt expression tended toincrease, but there was no statistical difference. Compared with control group, serumDAO, D-lactate levels and Endotoxin levels were significantly increased in high fatdiet-induced obese group.(2) After intervention, compared with OC group, the bodyweight in E group and EC group decreased significantly. Compared with OC and CPgroup,the visceral fat content decreased significantly in EC group, which suggestedexercise combined with corn-peptide intervention was effective in reducing weightand fat of obese rats. After intervention, compared with OC group, hepatic lipiddeposition and RORγt expression in liver were improved in three interventiongroups, liver Foxp3expression were increased in CP and EC group,but there was nostatistical difference, serum DAO level decreased significantly in CP group and Egroup, serum D-lactate level decreased significantly in three intervention groups.Correlation analysis showed that there was a significant positive correlation betweenDAO and Endotoxin (r=0.501,p=0.001), DAO and liver RORγt expression(r=0.647,p=0.002) after intervention. Conclusion: Our study demonstrated that (1) High-fat diet induced hepatic lipiddeposition, which suggested the occurrence of simple fatty liver, liver Th17/Tregimbalances may play an important role in the occurrence and development of hepaticsteatosis in obesity rats, the cause of liver Th17/Treg imbalance in obesity may berelated to changes in intestinal permeability.(2) Exercise combined with cornpeptide intervention could regulate liver Th17/Treg imbalance in obesity by reducingincreased intestinal permeability, thereby improving obesity induced hepaticsteatosis and liver inflammation.