血管紧张素 II 诱导的小鼠心肌成纤维细胞钙内流不依赖于 TRPC 通道。
Angiotensin-II-Evoked Ca Entry in Murine Cardiac Fibroblasts Does Not Depend on TRPC Channels.
机构信息
Pharmakologisches Institut, Ruprecht-Karls-Universität Heidelberg, INF 366, 69120 Heidelberg, Germany.
DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, 69120, Germany.
出版信息
Cells. 2020 Jan 29;9(2):322. doi: 10.3390/cells9020322.
TRPC proteins form cation conducting channels regulated by different stimuli and are regulators of the cellular calcium homeostasis. TRPC are expressed in cardiac cells including cardiac fibroblasts (CFs) and have been implicated in the development of pathological cardiac remodeling including fibrosis. Using Ca imaging and several compound TRPC knockout mouse lines we analyzed the involvement of TRPC proteins for the angiotensin II (AngII)-induced changes in Ca homeostasis in CFs isolated from adult mice. Using qPCR we detected transcripts of all genes in CFs; , and being the most abundant ones. We show that the AngII-induced Ca entry but also Ca release from intracellular stores are critically dependent on the density of CFs in culture and are inversely correlated with the expression of the myofibroblast marker α-smooth muscle actin. Our Ca measurements depict that the AngII- and thrombin-induced Ca transients, and the AngII-induced Ca entry and Ca release are not affected in CFs isolated from mice lacking all seven TRPC proteins (TRPC-hepta KO) compared to control cells. However, pre-incubation with GSK7975A (10 µM), which sufficiently inhibits CRAC channels in other cells, abolished AngII-induced Ca entry. Consequently, we conclude the dispensability of the TRPC channels for the acute neurohumoral Ca signaling evoked by AngII in isolated CFs and suggest the contribution of members of the Orai channel family as molecular constituents responsible for this pathophysiologically important Ca entry pathway.
TRPC 蛋白形成受不同刺激调节的阳离子传导通道,是细胞钙稳态的调节剂。TRPC 在心肌细胞中表达,包括心肌成纤维细胞(CFs),并与病理性心脏重构包括纤维化的发展有关。使用 Ca 成像和几种复合 TRPC 敲除小鼠系,我们分析了 TRPC 蛋白在成年小鼠分离的 CFs 中血管紧张素 II(AngII)诱导的 Ca 稳态变化中的作用。通过 qPCR,我们在 CFs 中检测到所有 基因的转录本; 、 和 表达丰度最高。我们表明,AngII 诱导的 Ca 内流以及细胞内储存的 Ca 释放严重依赖于培养物中 CFs 的密度,并且与成纤维细胞标记物α-平滑肌肌动蛋白的表达呈负相关。我们的 Ca 测量表明,与对照细胞相比,从缺乏所有七种 TRPC 蛋白的小鼠(TRPC-hepta KO)分离的 CFs 中,AngII 和凝血酶诱导的 Ca 瞬变以及 AngII 诱导的 Ca 内流和 Ca 释放不受影响。然而,用 GSK7975A(10 µM)预处理足以抑制其他细胞中的 CRAC 通道,可消除 AngII 诱导的 Ca 内流。因此,我们得出结论,TRPC 通道对于 AngII 在分离的 CFs 中引起的急性神经激素 Ca 信号作用是可有可无的,并表明 Orai 通道家族成员作为负责这种重要病理生理 Ca 内流途径的分子成分的贡献。