Aerobic exercise inhibits GSDME-dependent myocardial cell pyroptosis to protect ischemia-reperfusion injury

Abstract

Background: Acute myocardial infarction (AMI) remains a significant cause of global mortality, exacerbated by ischemia-reperfusion (IR) injury. Myocardial cell pyroptosis has emerged as a critical pathway influencing IR injury severity.

Methods: We aimed to investigate the cardioprotective effects of aerobic exercise on IR injury by examining the modulation of IGFBP2 and its impact on GSDME-dependent myocardial cell pyroptosis. Mechanistic pathways were explored using western blot analysis, ELISA, immunofluorescence, and echocardiography.

Results: Our findings demonstrate that aerobic exercise leads to increased circulating levels of IGFBP2, which effectively suppresses GSDME-dependent myocardial cell pyroptosis. This regulation occurs via the AKT-GSK3β signaling pathway, involving VDAC1 phosphorylation, thereby enhancing mitochondrial function and reducing oxidative stress.

Conclusion: In conclusion, our study highlights the role of IGFBP2 in mitigating GSDME-dependent pyroptosis as a mechanism through which aerobic exercise exerts cardioprotective effects against IR injury. These insights suggest potential therapeutic targets for managing acute myocardial infarction.

Keywords: AKT-GSK3β; Acute myocardial infarction; GSDME; IGFBP2; Ischemia-reperfusion; Pyroptosis.

Fig. 1

Aerobic exercise inhibits myocardial cell pyroptosis by elevating peripheral circulating IGFBP2 levels. A The diagram presents the protocol for the animal model used in the study. B IGFBP2 levels in serum from WT+IR, WT+Exercise+IR, IGFBP2_KO+Exercise+IR, IGFBP2_OE+IR mice measured by ELISA. C Echocardiographic results of each mouse group. D TTC staining results of mouse cardiac tissues from each mouse group. E TUNEL staining results of mouse cardiac tissues from each mouse group. F Western blot analysis of N-GSDME and cleaved-caspase3 in mouse cardiac tissues. G TUNEL staining of cardiomyocytes (IR, IR+IGFBP2). H Western blot detection of N-GSDME and cleaved-caspase3 in cardiomyocytes of each group

Fig. 2

The GSDME-dependent myocardial cell pyroptosis mediates heart IR injury. A Echocardiographic results and left ventricular thickness from control mice and GSDMEcKO (GE_{_}cKO) mice. B Triphenyl Tetrazolium Chloride (TTC) staining of heart tissues from control mice and GE_{_}cKO mice. C TUNEL staining results of heart tissues from control mice and GE_{_}cKO mice. D WB results of N-GSDME and cleaved-caspase3 in heart tissues of control mice and GE_{_}cKO mice. E TUNEL staining of WT, GE_{_}sh and GE_{_}OE cardiomyocytes. F Western blot analysis results of N-GSDME and cleaved-caspase3 in WT, GE_{_}sh and GE_{_}OE cardiomyocytes

Fig. 3

GSDME is required for the apoptosis of myocardial cells inhibited by IGFBP2 in IR heart. A Echocardiographic assessment results of mouse experimental groups including WT+ IR, GE_CKO+IR, IGFBP2_OE+IR, IGFBP2_KO+IR, IGFBP2_KO+GE_CKO+IR, IGFBP2_OE+GE_CKO+IR. B TTC staining results of mouse cardiac tissues of each mouse group. C TUNEL staining results of mouse cardiac tissues. D Western blot analysis of N-GSDME and cleaved-caspase3 in mouse cardiac tissues. E TUNEL staining of cardiomyocytes in cell experimental groups. F Western blot detection of N-GSDME and cleaved-caspase3 in cardiomyocytes of cell experimental groups

Fig. 4

IGFBP2 protects mitochondrial function of myocardial cell by upregulating AKT-GSK3β phosphorylation levels. A Western blot analysis of p-AKT, p-GSK3β, p-VDAC1, AKT, GSK3β, and VDAC1 levels in heart tissue from each mouse experimental group. B Electron microscopy of mouse heart tissue across experimental groups. C Quantification of ROS and MDA levels in mouse heart tissue across experimental groups. D Assessment of inflammatory cytokines and cleaved-caspase 1 levels in mouse heart tissue across experimental groups. E Western blot analysis of cardiomyocytes from various experimental groups showing protein expression levels of N-GSDME, cleaved-caspase3, p-AKT, p-GSK3β, p-VDAC1, AKT, GSK3β, and VDAC1. F Assessment of ROS levels in cardiomyocytes across experimental groups. G Measurement of MDA levels in cardiomyocytes across experimental groups. H Immunofluorescence staining of cardiomyocytes using ER-tracker (red) and Hoechst 33342 (blue) to visualize mitochondrial respiratory function

Fig. 5

Phosphorylation of VDAC1 inhibits glucose GSDME-dependent pyroptosis by modulating mitochondrial function. A TUNEL staining of cardiomyocytes in each experimental group. B Western blot analysis of cardiomyocytes from each experimental group showing protein expression levels of N-GSDME, cleaved-caspase3, p-AKT, p-GSK3β, p-VDAC1, AKT, GSK3β, and VDAC1. C Electron microscopy of cardiomyocytes from each experimental group. D Quantification of ROS and MDA levels in cardiomyocytes across experimental groups. E Immunofluorescence staining of cardiomyocytes using ER-tracker (red) and Hoechst 33342 (blue) to visualize mitochondrial respiratory function. F A proposed model for this study