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Hypoxia augments the calcium‐activated chloride current carried by anoctamin‐1 in cardiac vascular endothelial cells of neonatal mice
Author(s) -
Wu MingMing,
Lou Jie,
Song BinLin,
Gong YuanFeng,
Li YanChao,
Yu ChangJiang,
Wang QiuShi,
Ma TianXing,
Ma Ke,
Hartzell H Criss,
Duan Dayue Darrel,
Zhao Dan,
Zhang ZhiRen
Publication year - 2014
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/bph.12730
Subject(s) - hypoxia (environmental) , gene knockdown , western blot , calcium , chloride channel , patch clamp , chemistry , endocrinology , medicine , biology , microbiology and biotechnology , biochemistry , electrophysiology , gene , organic chemistry , oxygen
Background and Purpose The molecular identity of calcium‐activated chloride channels ( C a CC s) in vascular endothelial cells remains unknown. This study sought to identify whether anoctamin‐1 ( Ano 1, also known as TMEM 16 A ) functions as a CaCC and whether hypoxia alters the biophysical properties of Ano 1 in mouse cardiac vascular endothelial cells ( CVECs ). Experimental Approach Western blot, quantitative real‐time PCR , confocal imaging analysis and patch‐clamp analysis combined with pharmacological approaches were used to determine whether Ano 1 was expressed and functioned as CaCC in CVECs . Key Results Ano1 was expressed in CVECs . The biophysical properties of the current generated in the CVECs , including the Ca 2+ and voltage dependence, outward rectification, anion selectivity and the pharmacological profile, are similar to those described for C a CC s. The density of I Cl ( C a) detected in CVECs was significantly inhibited by T 16 A inh ‐ A 01, an Ano 1 inhibitor, and a pore‐targeting, specific anti‐ Ano1 antibody, and was markedly decreased in Ano 1 gene knockdown CVECs . The density of I Cl ( C a) was significantly potentiated in CVECs exposed to hypoxia, and this hypoxia‐induced increase in the density of I Cl ( C a) was inhibited by T 16 A inh ‐ A 01 or anti‐ Ano 1 antibody. Hypoxia also increased the current density of I Cl ( C a) in Ano 1 gene knockdown CVECs . Conclusions and Implications Ano 1 formed CaCC in CVECs of neonatal mice. Hypoxia enhances Ano 1‐mediated I Cl ( C a) density via increasing its expression, altering the ratio of its splicing variants, sensitivity to membrane voltage and to Ca 2+ . Ano 1 may play a role in the pathophysiological processes during ischaemia in heart, and therefore, Ano 1 might be a potential therapeutic target to prevent ischaemic damage.