Chemerin loss-of-function attenuates glucagon-like peptide-1 secretion in exercised obese mice

To investigate the role of chemerin reduction in mediating exercise-induced Glucagon-like peptide-1 (GLP-1) secretion and the amelioration of pancreatic β-cell function in obesity.

Obesity models were established using wild-type and chemerin systemic knockout mice, followed by 8 weeks of moderate-intensity continuous aerobic exercise training. Serum chemerin levels, GLP-1 synthesis, glucose tolerance, pancreatic β-cell function, structure, and apoptosis were assessed. In vitro experiments were conducted on STC-1 cells, derived from murine intestinal endocrine cells, to evaluate GLP-1 secretion following exogenous chemerin treatment. Additionally, colonic tissue inflammation and apoptosis were analyzed using qPCR and TUNEL staining.

In obese wild-type mice, moderate-intensity aerobic exercise significantly reduced serum chemerin levels, enhanced GLP-1 secretion, and improved glucose tolerance, pancreatic β-cell structure, function, and apoptosis. These effects were absent in obese chemerin knockout mice. Exogenous chemerin treatment reduced GLP-1 secretion in STC-1 cells. Furthermore, the beneficial effects of exercise on colonic inflammation and apoptosis observed in wild-type mice were abolished in chemerin knockout mice.

Reduction of chemerin is crucial for the beneficial effects of aerobic exercise on GLP-1 secretion and pancreatic β-cell function in obesity. The mechanisms behind these effects may involve improvements in colonic inflammation and apoptosis. These findings offer new insights into the molecular mechanisms through which exercise improves obesity-related metabolic dysfunction.