Plasticity of TRPC expression in arterial smooth muscle:: correlation with store-operated Ca2+ entry
Plasticity of TRPC expression in arterial smooth muscle:: correlation with store-operated Ca2+ entry
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DOI：
10.1152/ajpcell.00334.2004
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发表时间：
2005-04-01
影响因子：
5.5
通讯作者：
Hellstrand, P
中科院分区：
文献类型：
--
作者：
Bergdahl, A;Gomez, MF;Hellstrand, P
平滑肌收缩表型的丧失在动脉粥样硬化和血管成形术后再狭窄中起关键作用，但其早期信号尚不完全清楚。在这项研究中，我们探索了瞬时受体潜在规范(TRPC)蛋白的作用，这些蛋白被认为是介导存储操作的钙内流(SOCE)的。器官培养的大鼠脑动脉的收缩性能可保存数天，而SOCE则增加。与此相关的是，在培养3天的动脉分离细胞中，通过耗尽细胞内钙库而激活的硝苯地平不敏感的全细胞电流增加了50%。在器官培养后分离的细胞中，TRPC1和TRPC6的mRNA表达增加5倍以上，而TRPC3的表达降低。免疫荧光染色和/或免疫印迹显示，在器官培养过程中，动脉和分离细胞TRPC1和TRPC6蛋白表达上调。在完整的动脉中，TRPC4的表达与内皮细胞的数量相关。在储备耗尽后，添加钙离子会导致培养的动脉收缩，但在新鲜解剖的动脉中不会。针对细胞外表位的多克隆TRPC1抗体对这种收缩的抑制作用类似于50%。为探讨TRPC上调的基础及其可能的临床意义，将人乳内动脉段体外器官培养2 4h后，经球囊扩张培养至48h，扩张后TRPC1和TRPC6mRNA的表达较未扩张的对照节段递增。本研究结果表明，血管损伤增强了TRPC表达的可塑性，TRPC的表达与细胞对钙的处理有关，TRPC1是上调的钙通道的一个亚单位。
Loss of the smooth muscle contractile phenotype is critical in atherosclerosis and in restenosis after angioplasty, but its early signals are incompletely understood. In this study, we have explored the role of transient receptor potential canonical ( TRPC) proteins, which have been suggested to mediate store-operated Ca2+ entry (SOCE). Contractility of rat cerebral arteries in organ culture is preserved for several days, whereas SOCE is increased. In correlation with this increase is that nifedipine-insensitive whole cell current, activated by depletion of intracellular Ca2+ stores, was increased by 50% in cells isolated from arteries cultured for 3 days. TRPC1 and TRPC6 mRNA were more than fivefold increased in cells isolated after organ culture, whereas TRPC3 was decreased. Immunofluorescent staining and/or Western blotting of arteries and isolated cells showed upregulation of TRPC1 and TRPC6 proteins during organ culture. In intact arteries, TRPC4 expression correlated with the amount of endothelium present. Ca2+ addition after store depletion caused a contraction in cultured, but not in freshly dissected, arteries. A polyclonal TRPC1 antibody directed against an extracellular epitope inhibited this contraction by similar to 50%. To investigate the basis of the TRPC upregulation and assess its possible clinical significance, segments of human internal mammary artery were organ cultured for 24 h and then exposed to balloon dilatation in vitro, followed by further culturing for up to 48 h. After dilatation, TRPC1 and TRPC6 mRNA were progressively increased compared with undilated control segments. The results of this study indicate that vascular injury enhances plasticity in TRPC expression, that TRPC expression correlates with cellular Ca2+ handling, and that TRPC1 is a subunit of upregulated store-operated Ca2+ channels.