ABSTRACT
Aim To investigate whether Orai1 and BKCa form a physical and functional signal complex in glomerular mesangial cells ( GMCs) and reveal the role of high glucose treatment on Orai1-BKCa complex and SOCE-induced hyperpolarization. Methods The in-teraction of Orai1 and BKCa was evaluated by co-immu-noprecipitation ( co-IP ) . Western blot method was used to detect the expression levels of Orai1 and BKCa . SOCE was activated by Ca2+ depletion evoked by TG in normal glucose and high glucose. The DiBAC4(3) was employed as fluorescence indicator to measure the potential change of membrane. . Results The co-IP experiment results showed that Orai1 interacted with BKCa in GMCs. SOCE induced the hyperpolarization of GMCs. SOCE and SOCE-induced membrane hyperpol-orizaiton were enhanced by high glucose treatment for three days. In addition, the expression levels of Orai1 and BKCa were enhanced significantly in the high glu-cose-cultured cells. Conclusions Orai1 can form a signaling complex with BKCa , which participates in the regulation of hyperpolarization in GMCs and may be in-volved in the hyperpolarization in high glucose cultured GMCs.