Yang Hui, Xue Yumei, Kuang Sujuan, Zhang Mengzhen, Chen Jinghui, Liu Lin, Shan Zhixin, Lin Qiuxiong, Li Xiaohong, Yang Min, Zhou Hui, Rao Fang, Deng Chunyu
Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangzhou, Guangdong 510080, China.
Research Center of Medical Sciences, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, China.
Korean J Physiol Pharmacol. 2019 Mar;23(2):95-102. doi: 10.4196/kjpp.2019.23.2.95. Epub 2019 Feb 15.
Endoplasmic reticulum (ER) stress is mediated by disturbance of Ca homeostasis. The store-operated calcium (SOC) channel is the primary Ca channel in non-excitable cells, but its participation in agent-induced ER stress is not clear. In this study, the effects of tunicamycin on Ca influx in human umbilical vein endothelial cells (HUVECs) were observed with the fluorescent probe Fluo-4 AM. The effect of tunicamycin on the expression of the unfolded protein response (UPR)-related proteins BiP and CHOP was assayed by western blotting with or without inhibition of Orai1. Tunicamycin induced endothelial dysfunction by activating ER stress. Orai1 expression and the influx of extracellular Ca in HUVECs were both upregulated during ER stress. The SOC channel inhibitor SKF96365 reversed tunicamycin-induced endothelial cell dysfunction by inhibiting ER stress. Regulation of tunicamycin-induced ER stress by Orai1 indicates that modification of Orai1 activity may have therapeutic value for conditions with ER stress-induced endothelial dysfunction.
内质网（ER）应激由钙稳态紊乱介导。储存式钙（SOC）通道是非兴奋性细胞中的主要钙通道，但其在药物诱导的内质网应激中的作用尚不清楚。在本研究中，用荧光探针Fluo-4 AM观察衣霉素对人脐静脉内皮细胞（HUVECs）钙内流的影响。通过蛋白质免疫印迹法检测衣霉素对未折叠蛋白反应（UPR）相关蛋白BiP和CHOP表达的影响，实验中分别有无Orai1抑制剂。衣霉素通过激活内质网应激诱导内皮功能障碍。在内质网应激期间，HUVECs中Orai1表达和细胞外钙内流均上调。SOC通道抑制剂SKF96365通过抑制内质网应激逆转衣霉素诱导的内皮细胞功能障碍。Orai1对衣霉素诱导的内质网应激的调节表明，改变Orai1活性可能对内质网应激诱导的内皮功能障碍疾病具有治疗价值。
