Sildenafil inhibits chronically hypoxic upregulation of canonical transient receptor potential expression in rat pulmonary arterial smooth muscle
Sildenafil inhibits chronically hypoxic upregulation of canonical transient receptor potential expression in rat pulmonary arterial smooth muscle
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西地那非抑制大鼠肺动脉平滑肌中典型瞬时受体电位表达的慢性缺氧上调
DOI：
10.1152/ajpcell.00629.2008
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发表时间：
2010-01-01
影响因子：
5.5
通讯作者：
Wang, Jian
中科院分区：
文献类型：
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作者：
Lu, Wenju;Ran, Pixin;Wang, Jian
Lu W，Ran P，Zhang D，Peng G，Li B，Zhong N，Wang J. Sildenafil inhibits chronic hypoxic upregulation of canonical transmittance receptor potential expression in rat pulmonary arterial smooth muscle.美国生理学杂志细胞生理学298：C114-C123，2010年。首次发表于2009年11月4日; doi：10.1152/ajpcell.00629.2008。在肺动脉平滑肌细胞（PASMCs）中，钙池操纵的钙通道（被认为是由典型瞬时受体电位（TRPC）蛋白组成）的钙内流是细胞内游离钙浓度（[Ca 2 +]（i））和肺血管张力的重要决定因素。西地那非是一种V型磷酸二酯酶抑制剂，可增加细胞cGMP，最近被确定为治疗肺动脉高压的有前途的药物。我们先前证明，慢性缺氧升高PASMCs的基础[Ca 2 +]（i），这在很大程度上是由于增强了钙库操作的Ca 2+内流（SOCE）;此外，体外暴露于长时间缺氧（4%O-2，60 h）上调PASMCs中TRPC 1和TRPC 6的表达。我们研究了西地那非对PASMCs基础[Ca 2 +]（i）、SOCE和TRPC表达的影响。我们还研究了西地那非对慢性缺氧性肺动脉高压（CHPH）大鼠肺动脉平滑肌（PA）TRPC 1和TRPC 6表达的影响。与溶剂对照组相比，西地那非（300 nM）处理可抑制PASMCs中长时间缺氧诱导的1）基础[Ca 2 +]（i）、2）SOCE和3）TRPC mRNA和蛋白表达的增加。此外，西地那非（50 mg . kg（-1）。（-1）d）抑制慢性缺氧（10%O2，21 d）大鼠PA TRPC 1和TRPC 6 mRNA和蛋白表达，与右心室压力降低和右心室肥厚有关。此外，我们发现，在暴露于长时间缺氧的PASMCs中，通过其特异性小干扰RNA敲低TRPC 1或TRPC 6减弱了SOCE和基础[Ca 2 +]的缺氧增加（i），表明TRPC 1和TRPC 6表达增加与SOCE和基础[Ca 2 +]的缺氧增加之间存在因果关系（i）。这些结果表明，西地那非可能会通过下调TRPC 1和TRPC 6表达来降低SOCE，从而改变PASMC中的基础[Ca 2 +]（i），从而导致CHPH发生期间肺动脉血管张力降低。
Lu W, Ran P, Zhang D, Peng G, Li B, Zhong N, Wang J. Sildenafil inhibits chronically hypoxic upregulation of canonical transient receptor potential expression in rat pulmonary arterial smooth muscle. Am J Physiol Cell Physiol 298: C114-C123, 2010. First published November 4, 2009; doi:10.1152/ajpcell.00629.2008.-In pulmonary arterial smooth muscle cells (PASMCs), Ca2+ influx through store-operated Ca2+ channels thought to be composed of canonical transient receptor potential (TRPC) proteins is an important determinant of intracellular free calcium concentration ([Ca2+](i)) and pulmonary vascular tone. Sildenafil, a type V phosphodiesterase inhibitor that increases cellular cGMP, is recently identified as a promising agent for treatment of pulmonary hypertension. We previously demonstrated that chronic hypoxia elevated basal [Ca2+](i) in PASMCs due in large part to enhanced store-operated Ca2+ entry (SOCE); moreover, ex vivo exposure to prolonged hypoxia (4% O-2 for 60 h) upregulated TRPC1 and TRPC6 expression in PASMCs. We examined the effect of sildenafil on basal [Ca2+](i), SOCE, and the expression of TRPC in PASMCs under prolonged hypoxia exposure. We also examined the effect of sildenafil on TRPC1 and TRPC6 expression in pulmonary arterial smooth muscle (PA) from rats that developed chronically hypoxic pulmonary hypertension (CHPH). Compared with vehicle control, treatment with sildenafil (300 nM) inhibited prolonged hypoxia induced increases of 1) basal [Ca2+](i), 2) SOCE, and 3) mRNA and protein expression of TRPC in PASMCs. Moreover, sildenafil (50 mg . kg(-1) . day(-1)) inhibited mRNA and protein expression of TRPC1 and TRPC6 in PA from chronically hypoxic (10% O-2 for 21 days) rats, which was associated with decreased right ventricular pressure and right ventricular hypertrophy. Furthermore, we found, in PASMCs exposed to prolonged hypoxia, that knockdown of TRPC1 or TRPC6 by their specific small interference RNA attenuated the hypoxic increases of SOCE and basal [Ca2+](i), suggesting a cause and effect link between increases of TRPC1 and TRPC6 expression and the hypoxic increases of SOCE and basal [Ca2+](i). These results suggest that sildenafil may alter basal [Ca2+](i) in PASMCs by decreasing SOCE through downregulation of TRPC1 and TRPC6 expression, thereby contributing to decreased vascular tone of pulmonary arteries during the development of CHPH.