GYY4137 protects against type 2 diabetes mellitus-associated myocardial autophagy by suppressing FOXO1 signal pathway

Purpose: Diabetic cardiomyopathy (DCM) is a major complication of type 2 diabetes mellitus (T2DM), but its effective prevention and treatment are still limited. We investigated the effects of GYY4137, a slow-releasing hydrogen sulfide donor, and its downstream mediator forkhead box protein O1 (FOXO1) on T2DM-associated DCM. Methods: In vivo, T2DM mice were induced by a high-fat diet coupled with streptozotocin injection. Intragastric administration of GYY4137 was also performed. In vitro, AC16 cardiomyocytes were treated with glucose and palmitate to mimic high-glucose and high-fat (HGHF) conditions, in which GYY4137 or a FOXO1 inhibitor (AS1842856) was also introduced. Bioinformatics analysis was performed using public GEO datasets. Results: GYY4137 demonstrated a protective effect against cardiac dysfunction, fibrosis, and autophagy in cardiac tissues of T2DM mice. Moreover, GYY4137 alleviated cell injury and lipid accumulation in HGHF-treated AC16 cells. In both in vivo and in vitro models, hyperactivation of autophagy was dampened by GYY4137. Bioinformatic analysis revealed the potential role of the FOXO pathway and autophagy in DCM. Further experiments showed that GYY4137 rescued diabetes-induced overexpression of FOXO1. AS1842856 displayed a notable capacity to shield cardiomyocytes against diabetes-induced injury similar to that achieved by GYY4137. Conclusion: GYY4137 protected against cardiac dysfunction and fibrosis in T2DM mice, and the mechanism might involve suppression of FOXO1-induced autophagy.