Exercise protects intestinal epithelial barrier from high fat diet- induced permeabilization through SESN2/AMPKα1/HIF-1α signaling.

Over-nutrition and a sedentary lifestyle are associated with increased intestinal permeability. This condition promotes obesity and associated metabolic disorders. Sestrin2 (SESN2) is a stress-inducible protein thought to promote the survival and recovery of epithelial cells and act as a positive regulator in exercise-induced improvements of glycolipid metabolism. Here we aimed to test the hypothesis that chronic exercise can protect intestinal barrier function against high-fat diet induced permeabilization through SESN2. WT and SESN2 mice were randomly assigned to five groups, fed with either normal chow or high fat diet (HFD), and provided with or without exercise training for 15-week. Metabolic parameters, fecal microbiota composition, and intestinal barrier integrity were assessed. The role of the gut microbiota was investigated by administering a mixture of broad-spectrum antibiotics (ABX). Fifteen-week HFD feeding induced dysmetabolism, dysbiosis and gut barrier dysfunctions in the WT mice. These effects were exaggerated in SESN2 mice. Chronic aerobic exercise significantly reversed HFD-induced pathologic changes, while SESN2 ablation weakened the protective effects of exercise. ABX did not abolish the differences in gut barrier function between WT and SESN2 mice. We speculated that SESN2 may protect intestinal integrity partly independent of gut microbiome. Combining ex vivo and in vivo approaches, we demonstrated that SESN2/pAMPK-Thr172/HIF-1α pathway may play an important role in exercise- improved intestinal permeability. Taken together, our study demonstrated that HFD and SESN2-KO have synergistic effects on intestinal homeostasis. SESN2 is crucial in exercise-improved intestinal permeability.