Diabetes, Metabolic Syndrome and Obesity (Feb 2020)
Caspase-3 Promotes Diabetic Kidney Disease Through Gasdermin E-Mediated Progression to Secondary Necrosis During Apoptosis
Abstract
Si Wen,1,* Zhao-Hua Wang,2,* Cong-Xiao Zhang,1 Ying Yang,1 Qiu-Ling Fan1 1Department of Nephrology, First Hospital of China Medical University, Shenyang, People’s Republic of China; 2Affiliated Dalian Friendship Hospital of Dalian Medical University, Dalian, People’s Republic of China*These authors contributed equally to this workCorrespondence: Qiu-Ling FanDepartment of Nephrology, First Hospital of China Medical University, No. 155 Nanjing Bei Street, Shenyang 110001, People’s Republic of ChinaTel +86 13904012680Email [email protected]: Apoptosis has been repeatedly linked with diabetic kidney disease (DKD), which is a programmed cell death mediated by effector caspases-3, 6 and 7, targeting > 600 substrates. However, the pathophysiologic correlations of this process remain obscure. As a putative tumor suppressor, gasdermin E (GSDME) was recently reported to be cleaved by caspase-3 to produce a GSDME-N fragment which targets the plasma membrane to switch apoptosis to secondary necrosis. However, it remains elusive whether GSDME is involved in the regulation of DKD.Methods: To evaluate the therapeutic potential of caspase-3 inhibition in DKD, we administered caspase-3 inhibitor Z-DEVD-FMK to STZ-induced diabetic mice for eight weeks. Albuminuria, renal function, pathological changes, and indicators of secondary necrosis and fibrosis were evaluated. In vitro, human tubule epithelial cells (HK-2 cells) were subjected to high-glucose treatment. Secondary necrosis was determined by LDH release, GSDME cleavage, and morphological feature under confocal microscopy. Z-DEVD-FMK and GSDME inhibition by shRNA were administered to suppress the cleavage and expression of GSDME. Flow cytometry, cytotoxicity assay and immunoblot were used to assess cell death and fibrogenesis.Results: Caspase-3 inhibition by Z-DEVD-FMK ameliorated albuminuria, renal function, and tubulointerstitial fibrosis in diabetic mice. The nephroprotection mediated by Z-DEVD-FMK was potentially associated with inhibition of GSDME. In vitro, molecular and morphological features of secondary necrosis were observed in glucose-stressed HK-2 cells, evidenced by active GSDME cleavage, ballooning of the cell membrane, and release of cellular contents. Here we showed that caspase-3 inhibition prevented GSDME activation and cell death in glucose-treated tubular cells. Specifically, knocking down GSDME directly inhibited secondary necrosis and fibrogenesis.Conclusion: These data suggest GSDME-dependent secondary necrosis plays a crucial role in renal injury, and provides a new insight into the pathogenesis of DKD and a promising target for its treatment.Keywords: GSDME, DFNA5, secondary necrosis, diabetic kidney disease, Z-DEVD-FMK
