Connexin43 Modulates X-Ray-Induced Pyroptosis in Human Umbilical Vein Endothelial Cells

作     者：LI Chen TIAN Mei GOU Qiao JIA Yong Rui SU Xu 

作者机构：China CDC Key Laboratory of Radiological Protection and Nuclear Emergency National Institute for Radiological Protection Chinese Center for Disease Control and Prevention Medical and Health Analysis Center Peking University 

出 版 物：《Biomedical and Environmental Sciences》 (生物医学与环境科学（英文版）)

年 卷 期：2019年第32卷第3期

页      面：177-188页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 09[农学] 

基　　金：supported by grands from Research Institute for Social Public Welfare Research Foundation [grant no.2005DIB1J087] 

主　　题：X-ray Connexin43 HUVECs Pyroptosis 

摘      要：Objective Pyroptosis is an inflammatory form of programmed cell death. This phenomenon has been recently reported to play an important role in radiation-induced normal tissue injury. Connexin43(Cx43) is a gap junction protein that regulates cell growth and apoptosis. In this study, we investigated the effect of Cx43 on X-ray-induced pyroptosis in the human umbilical vein endothelial cells(HUVECs). Methods HUVECs, Cx43 overexpression, and Cx43 knockdown strains were irradiated with 10 Gy. Proteins were detected using western blot analysis. Cell pyroptosis was evaluated using the fluorescence-labeled inhibitor of caspase assay(FLICA) and propidium iodide staining through flow cytometry and confocal microscopy. Cell morphology and cytotoxicity were detected by scanning electron microscopy and lactate dehydrogenase release assay, respectively. Results Irradiation with 10 Gy X-ray induced pyroptosis in the HUVECs and reduced Cx43 expression. The pyroptosis in the HUVECs was significantly attenuated by overexpression of Cx43 as it decreased the level of active caspase-1. However, interference of Cx43 expression with si RNA significantly promoted pyroptosis by increasing the active caspase-1 level. Pannexin1(Panx1), a gap junction protein regulates pyroptosis, and its cleaved form is used to evaluate channel opening and active state. The level of cleaved Panx1 in the HUVECs and Cx43 knockdown strains increased in the presence of X-ray, but decreased in the Cx43 overexpression strains. Furthermore, interference of Panx1 with si RNA alleviated the upregulation of pyroptosis caused by Cx43 knockdown. Conclusion Results suggest that single high-dose X-ray irradiation induces pyroptosis in the HUVECs. In addition, Cx43 regulates pyroptosis directly by activating caspase-1 or indirectly by cleaving Panx1.