Implication of the ryanodine receptor in TRPV4-induced calcium response in pulmonary arterial smooth muscle cells from normoxic and chronically hypoxic rats
Implication of the ryanodine receptor in TRPV4-induced calcium response in pulmonary arterial smooth muscle cells from normoxic and chronically hypoxic rats
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DOI：
10.1152/ajplung.00244.2011
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发表时间：
2012-11-01
影响因子：
4.9
通讯作者：
Esteve, Eric
中科院分区：
文献类型：
--
作者：
Dahan, Diana;Ducret, Thomas;Esteve, Eric
李建军，李建军，李建军，等。ryanodine受体在低氧大鼠肺动脉平滑肌细胞钙反应中的作用。[J] .中华医学会肺科杂志，2016,31(4):387 - 398。2012年9月7日首次发表；doi: 10.1152 / ajplung.00244.2011。-越来越多的证据表明，瞬时受体电位（TRP）通道与肺血管中的钙信号和各种细胞功能有关。本研究旨在探讨常氧（Nx）和慢性缺氧（CH）大鼠肺动脉中4型香草TRP亚家族（TRPV4）的表达、功能作用及其与网状钙通道的偶联。特异性激动剂4 α - phorpol -12,13-didecanoate （4 α - pdd, 5 μ M）激活TRPV4可增加细胞内钙浓度（[Ca2+](i)）。高浓度ryanodine （100 μ M）或慢性咖啡因（5 μ M）阻断ryanodine受体（RyR），但对肌醇三磷酸受体拮抗剂xestospongin C （10 μ M）不敏感，显著降低了这种效应。仅用10 μ M丹曲林抑制RyR1和RyR3并没有减弱4 α - pdd诱导的[Ca2+](i)的增加。Western blotting实验显示，与Nx大鼠相比，CH大鼠肺动脉中TRPV4和RyR2的表达均有所增加。因此，膜片钳技术测量的4 α - pdd激活电流在CH大鼠的肺动脉平滑肌细胞（PASMC）中比Nx大鼠增加。4 α - pdd增加了动脉环的等长张力，这种反应在慢性缺氧条件下也增强了。4 α - pdd诱导的钙反应、电流和收缩均被选择性TRPV4阻滞剂HC-067047抑制。总的来说，我们的研究结果提供了TRPV4和RyR2在PASMC中Ca2+释放机制和收缩中的相互作用的证据。本研究为PASMC中复杂的钙信号通路提供了新的见解，并指出了TRPV4-RyR2信号通路在可能导致肺动脉高压的缺氧条件下的重要性。
Dahan D, Ducret T, Quignard J, Marthan R, Savineau J, Esteve E. Implication of the ryanodine receptor in TRPV4-induced calcium response in pulmonary arterial smooth muscle cells from normoxic and chronically hypoxic rats. Am J Physiol Lung Cell Mol Physiol 303: L824-L833, 2012. First published September 7, 2012; doi:10.1152/ajplung.00244.2011.-There is a growing body of evidence indicating that transient receptor potential (TRP) channels are implicated in calcium signaling and various cellular functions in the pulmonary vasculature. The aim of this study was to investigate the expression, functional role, and coupling to reticulum calcium channels of the type 4 vanilloid TRP subfamily (TRPV4) in the pulmonary artery from both normoxic (Nx) and chronically hypoxic (CH) rats. Activation of TRPV4 with the specific agonist 4 alpha-phorbol-12,13-didecanoate (4 alpha-PDD, 5 mu M) increased the intracellular calcium concentration ([Ca2+](i)). This effect was significantly reduced by a high concentration of ryanodine (100 mu M) or chronic caffeine (5 mM) that blocked ryanodine receptor (RyR) but was insensitive to xestospongin C (10 mu M), an inositol trisphosphate receptor antagonist. Inhibition of RyR1 and RyR3 only with 10 mu M of dantrolene did not attenuate the 4 alpha-PDD-induced [Ca2+](i) increase. Western blotting experiments revealed the expression of TRPV4 and RyR2 with an increase in both receptors in pulmonary arteries from CH rats vs. Nx rats. Accordingly, the 4 alpha-PDD-activated current, measured with patch-clamp technique, was increased in pulmonary artery smooth muscle cells (PASMC) from CH rats vs. Nx rats. 4 alpha-PDD increased isometric tension in artery rings, and this response was also potentiated under chronic hypoxia conditions. 4 alpha-PDD-induced calcium response, current, and contraction were all inhibited by the selective TRPV4 blocker HC-067047. Collectively, our findings provide evidence of the interplay between TRPV4 and RyR2 in the Ca2+ release mechanism and contraction in PASMC. This study provides new insights onto the complex calcium signaling in PASMC and point out the importance of the TRPV4-RyR2 signaling pathway under hypoxic conditions that may lead to pulmonary hypertension.