酸中毒对小鼠成纤维细胞瞬时受体电位通道亚族M7影响的实验研究

目的 观察小鼠成纤维细胞(CFs)在心肌细胞酸中毒时瞬时受体电位通道亚族M7(TRPM7)电流的变化及其对小鼠CFs胶原生成的影响,探讨TRPM7离子通道在心脏纤维化形成中的病理生理作用. 方法 (1)制备并分离小鼠CFs细胞;(2)培养传代小鼠CFs细胞;(3)应用膜片钳技术观察CFs在低pH值溶液下TRPM7L通道内外向电流特征;(4)钙荧光显像技术观察酸性pH值对小鼠CFs细胞Ca2+内流的影响. 结果 (1)小鼠CFs细胞富含TRPM7通道,且TRPM7L通道电生理特性均与TRPM7通道一致;(2)酸性液体能使小鼠CFs的Ca2+内流增加,pH 4.0较pH7.0时其钙荧光F340/F380比值从1.0增至4.6,(t=2.72,P<0.01). 结论 (1)TRPM7是小鼠CFs细胞中TRPM7L电流的分子基础,TRPM7L电流是CFs中钙内流主要媒介;(2)心肌细胞酸中毒可通过调节TRPM7L介导的Ca2+信号机制影响CFs细胞的病理生理功能.

Study on the effects of acidosis on transient receptor potential channel M7 (TRPM7) in mouse cardiac fibroblast

Objective To investigate the effects of acidosis on the current change of transient receptor potential channel M7 (TRPM7) and collagen production in mouse cardiac fibroblast (MCFs), and to explore the pathophysiological function of TRPM7 on the cardiac fibrosis. Methods (1) The model of MCFs was established and isolated. (2) MCFs was subcuhured. (3) Patch clamp technique was used to observe the current characteristics of TRPM7 in low PH solutions. (4) The influence of acidic condition on Ca2+ influx in MCFs was recorded by calcium fluorescent indicators. Results (1) There was a high level expression of TRPM7 in MCFs and the electrophysiological characteristics of TRPM7-like (TRPM7L) was similar to that of TRPM7. (2) Ca2+ influx was increased in acidic condition, and the F340/F380 ratio was increased from 1.0 to 4. 6 at pH 4.0 compared with pH 7.0 (t=2.72, P<0.01). Conclusions (1) TRPM7 is the molecular basis of the native TRPM7L in MCFs and TRPM7L plays an important role in Ca2+ influx. (2) The pathophysiological function of MCFs is influenced by regulation of Ca2+ influx mediated by TRPM7L in the condition of acidosis.