Potential Role of Aerobic Exercise in Attenuating Diabetic Cardiomyopathy via Modulation of P2X4-Mediated NLRP3...

Introduction: Diabetic cardiomyopathy (DCM) is a common complication of diabetes characterized by chronic low-grade inflammation. Exercise has been recognized as an effective intervention for DCM; however, its underlying mechanisms remain incompletely understood.

Pyroptosis regulation by exercise was examined using DCM and HFD mouse models. In vitro, H9C2 cardiomyocytes were exposed to high glucose or palmitic acid to mimic diabetic condition. The AMPK agonist AICAR was applied to H9C2 cells to reproduce the molecular effects of exercise. WB and caspase-1 activity assays analyzed protein expression and inflammasome activation. Cell death was assessed by cell viability, LDH release, and microscopy.

Exercise attenuated pyroptosis in DCM, prevented the upregulation of P2X4 and PANX1, inhibited NLRP3 activation, and reduced GSDMD and IL-1β cleavage in DCM mouse hearts, without altering P2X7 levels. In HFD-fed obese mice, exercise suppressed P2X4 expression, which correlated with NLRP3 activation, whereas P2X7 remained elevated. In vitro, high glucose alone did not induce significant H9C2 cell death or upregulate P2X4/P2X7 expression, whereas palmitic acid promoted concentration-dependent increases in P2X4 and NLRP3 expression, caspase-1 activity, and necrosis. Exercise and AICAR share a common mechanism in inhibiting NLRP3 inflammasome activation through P2X4, while AICAR exhibits a partial effect on P2X7 compared with exercise.

These findings highlight P2X4 as a critical mediator of NLRP3-driven pyroptosis in the diabetic heart. Exercise ameliorates myocardial inflammation in DCM and appears to act primarily through suppressing P2X4, providing new insight into its cardioprotective mechanisms and suggesting P2X4 as a potential therapeutic target.