Multiple H(+) sensors mediate the extracellular acidification-induced [Ca(2+)](i) elevation in cultured rat ventricular cardiomyocytes.
Multiple H(+) sensors mediate the extracellular acidification-induced [Ca(2+)](i) elevation in cultured rat ventricular cardiomyocytes.
复制标题
多个H传感器介导培养的大鼠心室心肌细胞外酸化诱导的[Ca2]i升高
DOI：
10.1038/srep44951
复制
发表时间：
2017-03-23
影响因子：
4.6
通讯作者：
Hu ZL
中科院分区：
文献类型：
--
作者：
Hu YL;Mi X;Huang C;Wang HF;Song JR;Shu Q;Ni L;Chen JG;Wang F;Hu ZL
已知酸中毒会引起“Ca 2+瞬变”，但其机制仍不确定。在这里，我们证明了多种H+传感器，如ASIC，TRPV 1和质子敏感G蛋白偶联受体（GPCR）参与胞外酸化诱导的细胞内钙（[Ca 2 +]i）升高。通过钙离子成像技术，我们观察到ASIC和TRPV 1通道抑制剂都能抑制细胞外酸中毒引起的培养大鼠心肌细胞[Ca ~（2+）]i升高。然后通过RT-PCR、免疫印迹和免疫荧光等方法对两种通道的mRNA和蛋白进行鉴定。细胞外酸化诱导ASIC样和TRPV 1样电流，表明功能性ASIC和TRPV 1通道共同介导细胞外钙离子内流。此外，无论是用毒胡萝卜素或IP 3受体阻断剂2-APB或PLC抑制剂U 73122预耗竭肌浆网（SR）Ca 2+均可显著减弱[Ca 2 +]i的升高，表明细胞内Ca 2+储存和PLC-IP 3信号也参与了酸中毒诱导的[Ca 2 +]i升高。通过使用遗传学和药理学方法，我们确定卵巢癌G蛋白偶联受体1（OGR 1）可能是酸中毒诱导的[Ca 2 +]i释放的另一个主要成分。这些结果表明，多个H+敏感受体参与了心脏酸中毒引起的“Ca 2+瞬变”。
Acidosis has been known to cause “Ca2+ transients”, however, the mechanism is still uncertain. Here, we demonstrated that multiple H+ sensors, such as ASICs, TRPV1 and proton-sensing G protein coupled receptors (GPCRs) are involved in extracellular acidification-induced intracellular calcium ([Ca2+]i) elevation. By using calcium imaging measures, we observed that both ASIC and TRPV1 channels inhibitors suppressed the [Ca2+]i elevation induced by extracellular acidosis in cultured rat cardiac myocytes. Then, both channels mRNA and proteins were identified by RT-PCR, western blotting and immunofluorescence. ASIC-like and TRPV1-like currents were induced by extracellular acidification, suggesting that functional ASIC and TRPV1 channels jointly mediated extracellular calcium entry. Furthermore, either pre-exhaustion of sarcoplasmic reticulum (SR) Ca2+ with thapsigargin or IP3 receptor blocker 2-APB or PLC inhibitor U73122 significantly attenuated the elevation of [Ca2+]i, indicating that the intracellular Ca2+ stores and the PLC-IP3 signaling also contributed to the acidosis-induced elevation of [Ca2+]i. By using genetic and pharmacological approaches, we identified that ovarian cancer G protein-coupled receptor 1 (OGR1) might be another main component in acidosis-induced release of [Ca2+]i. These results suggest that multiple H+-sensitive receptors are involved in “Ca2+ transients” induced by acidosis in the heart.