Membrane hyperpolarization induced by endoplasmic reticulum stress facilitates Ca2+ influx to regulate cell cycle progression in brain capillary endothelial cells

Upregulation of the kir2.1 channel during endoplasmic reticulum (er) stress in t-bbec117,an immortalized bovine brain endothelial cell line,caused a sustained increase in intracellular ca2+ concentration ([ca 2+]i) and a facilitation of cell death. expressions of ca2+ influx channels (trpc,orai1,stim1) were unchanged by er stress. the er stress-induced [ca2+]i increase was mainly attributed to the deeper resting membrane potential due to kir2.1 upregulation. er stress arrested at the g2/m phase and it was attenuated by an inhibitor of kir2.1. these results indicate that kir2.1 upregulation by er stress facilitates cell death via regulation of cell cycle progression in t-bbec117. © the japanese pharmacological society.