Aerobic exercise attenuates high-fat diet-induced glycometabolism abnormalities in skeletal muscle of rats via EGR-1/PTP1B signaling pathway

Objective Defects in glycogen anabolism led to the development of insulin resistance (IR). Aerobic exercise ameliorates IR by augmenting insulin signaling, yet, the precise mechanism behind this improvement remains unclear. This study explored whether 6 weeks aerobic exercise enhances glycogen anabolism and insulin sensitivity via EGR-1/PTP1B signaling pathway in skeletal muscle. Methods Sprague-Dawley rats fed a high-fat diet (HFD) performed treadmill exercise, and were examined for an oral glucose tolerance test and IR. PAS staining and anthrone colorimetry were used to assess the skeletal muscle glycogen content. RT-qPCR, western blot and immunofluorescence were used to detect EGR-1/PTP1B pathway and associated signaling molecules. Results Results showed that exercise reduced blood glucose levels and HOMA-IR, increased muscle glycogen content, inhibited EGR-1, PTP1B, and GSK-3β mRNA and protein levels, and promoted IRS-1, AKT, and GLUT4 protein and mRNA expression. Conclusion In summary, aerobic exercise facilitates skeletal muscle glycogen anabolism and improves insulin sensitivity in HFD rats through the EGR-1/PTP1B pathway, with significant implications for preventing IR.