IP3R2-mediated Ca2+ release promotes LPS-induced cardiomyocyte pyroptosis via the activation of NLRP3/Caspase-1/GSDMD pathway

Qing-Rui Wu; Hui Yang; Hui-Dan Zhang; Yong-Jiang Cai; Yan-Xiang Zheng; Heng Fang; Zi-Fan Wang; Su-Juan Kuang; Fang Rao; Huan-Lei Huang; Chun-Yu Deng; Chun-Bo Chen

doi:10.1038/s41420-024-01840-8

IP3R2-mediated Ca²⁺ release promotes LPS-induced cardiomyocyte pyroptosis via the activation of NLRP3/Caspase-1/GSDMD pathway

Cell Death Discov. 2024 Feb 20;10(1):91. doi: 10.1038/s41420-024-01840-8.

Authors

Qing-Rui Wu^#^{1

2}, Hui Yang^#², Hui-Dan Zhang^#³, Yong-Jiang Cai⁴, Yan-Xiang Zheng², Heng Fang⁵, Zi-Fan Wang⁴, Su-Juan Kuang², Fang Rao^{1

2}, Huan-Lei Huang⁶, Chun-Yu Deng^{7

8

9}, Chun-Bo Chen^{10

11}

Affiliations

¹ School of Medicine, South China University of Technology, 510006, Guangzhou, China.
² Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, 510080, Guangzhou, Guangdong, China.
³ Department of Emergency Medicine, Qilu Hospital of Shandong University, 250012, Jinan, China.
⁴ School of Pharmaceutical Sciences, Southern Medical University, 510515, Guangzhou, China.
⁵ Department of Critical Care Medicine, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China.
⁶ Department of Cardiovascular Surgery, Guangdong Provincial People's Hospital, Guangzhou, China.
⁷ School of Medicine, South China University of Technology, 510006, Guangzhou, China. sydengchunyu@scut.edu.cn.
⁸ Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Southern Medical University, 510080, Guangzhou, Guangdong, China. sydengchunyu@scut.edu.cn.
⁹ School of Pharmaceutical Sciences, Southern Medical University, 510515, Guangzhou, China. sydengchunyu@scut.edu.cn.
¹⁰ School of Medicine, South China University of Technology, 510006, Guangzhou, China. gghicu@163.com.
¹¹ Department of Critical Care Medicine, Shenzhen People's Hospital, The Second Clinical Medical College of Jinan University, The First Affiliated Hospital of Southern University of Science and Technology, 518000, Shenzhen, Guangdong Province, China. gghicu@163.com.

^# Contributed equally.

Abstract

Pyroptosis plays a crucial role in sepsis, and the abnormal handling of myocyte calcium (Ca²⁺) has been associated with cardiomyocyte pyroptosis. Specifically, the inositol 1,4,5-trisphosphate receptor type 2 (IP3R2) is a Ca²⁺ release channel in the endoplasmic reticulum (ER). However, the specific role of IP3R2 in sepsis-induced cardiomyopathy (SIC) has not yet been determined. Thus, this study aimed to investigate the underlying mechanism by which IP3R2 channel-mediated Ca²⁺ signaling contributes to lipopolysaccharide (LPS)-induced cardiac pyroptosis. The SIC model was established in rats by intraperitoneal injection of LPS (10 mg/kg). Cardiac dysfunction was assessed using echocardiography, and the protein expression of relevant signaling pathways was analyzed using ELISA, RT-qPCR, and western blot. Small interfering RNAs (siRNA) and an inhibitor were used to explore the role of IP3R2 in neonatal rat cardiomyocytes (NRCMs) stimulated by LPS in vitro. LPS-induced NLRP3 overexpression and GSDMD-mediated pyroptosis in the rats' heart. Treatment with the NLRP3 inhibitor MCC950 alleviated LPS-induced cardiomyocyte pyroptosis. Furthermore, LPS increased ATP-induced intracellular Ca²⁺ release and IP3R2 expression in NRCMs. Inhibiting IP3R activity with xestospongin C (XeC) or knocking down IP3R2 reversed LPS-induced intracellular Ca²⁺ release. Additionally, inhibiting IP3R2 reversed LPS-induced pyroptosis by suppressing the NLRP3/Caspase-1/GSDMD pathway. We also found that ER stress and IP3R2-mediated Ca²⁺ release mutually regulated each other, contributing to cardiomyocyte pyroptosis. IP3R2 promotes NLRP3-mediated pyroptosis by regulating ER Ca²⁺ release, and the mutual regulation of IP3R2 and ER stress further promotes LPS-induced pyroptosis in cardiomyocytes.