Pregnenolone sulphate- and cholesterol-regulated TRPM3 channels coupled to vascular smooth muscle secretion and contraction.
Pregnenolone sulphate- and cholesterol-regulated TRPM3 channels coupled to vascular smooth muscle secretion and contraction.
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DOI：
10.1161/circresaha.110.219329
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发表时间：
2010-05-14
影响因子：
20.1
通讯作者：
Beech DJ
中科院分区：
文献类型：
--
作者：
Naylor J;Li J;Milligan CJ;Zeng F;Sukumar P;Hou B;Sedo A;Yuldasheva N;Majeed Y;Beri D;Jiang S;Seymour VA;McKeown L;Kumar B;Harteneck C;O'Regan D;Wheatcroft SB;Kearney MT;Jones C;Porter KE;Beech DJ
瞬时受体电位Melastatin-3（TRPM 3）是由神经类固醇硫酸双烯醇酮激活的钙渗透性离子通道，并与β细胞中的胰岛素分泌正偶联。虽然已经报道了血管TRPM 3 mRNA，但对TRPM 3蛋白及其在心血管系统中的调节和功能还没有了解。确定TRPM 3在血管生物学中的相关性和调节。在收缩和增殖的血管平滑肌细胞中检测到TRPM 3在mRNA和蛋白水平上的表达。由硫酸双烯醇酮或鞘氨醇引起的钙内流被TRPM 3阻断抗体或通过RNA干扰敲低TRPM 3抑制。还检测到低水平的组成型TRPM 3活性。在增殖细胞中，通道活性通过钙依赖性机制与白细胞介素-6分泌呈负相关。在新鲜分离的主动脉，TRPM 3正调制的收缩反应独立的L-型钙通道。引起反应所需的硫酸双烯醇酮浓度高于已知的类固醇血浆浓度，导致对其他刺激物的筛选。β-环糊精是TRPM 3的少数刺激物之一，揭示了通道被内源性胆固醇（异烯醇酮的前体）部分抑制。胆固醇升高进一步抑制通道活性，并且胆固醇负荷产生泡沫细胞排除了TRPM 3活性的观察。数据表明TRPM 3在血管平滑肌细胞收缩和增殖表型中的功能相关性、组成性通道活性的重要性、胆固醇的调节以及硫酸孕烯醇酮在治疗性血管调节中的潜在价值。
Transient Receptor Potential Melastatin-3 (TRPM3) is a calcium-permeable ion channel activated by the neurosteroid pregnenolone sulphate and positively coupled to insulin secretion in β-cells. Although vascular TRPM3 mRNA has been reported, there is no knowledge of TRPM3 protein or its regulation and function in the cardiovascular system. To determine the relevance and regulation of TRPM3 in vascular biology. TRPM3 expression was detected at mRNA and protein levels in contractile and proliferating vascular smooth muscle cells. Calcium entry evoked by pregnenolone sulphate or sphingosine was suppressed by TRPM3 blocking antibody or knock-down of TRPM3 by RNA interference. Low-level constitutive TRPM3 activity was also detected. In proliferating cells, channel activity was coupled negatively to interleukin-6 secretion via a calcium-dependent mechanism. In freshly-isolated aorta, TRPM3 positively modulated contractile responses independently of L-type calcium channels. Concentrations of pregnenolone sulphate required to evoke responses were higher than the known plasma concentrations of the steroids, leading to a screen for other stimulators. β-cyclodextrin was one of few stimulators of TRPM3, revealing the channels to be partially suppressed by endogenous cholesterol, the precursor of pregnenolone. Elevation of cholesterol further suppressed channel activity and loading with cholesterol to generate foam cells precluded observation of TRPM3 activity. The data suggest functional relevance of TRPM3 in contractile and proliferating phenotypes of vascular smooth muscle cells, significance of constitutive channel activity, regulation by cholesterol, and potential value of pregnenolone sulphate in therapeutic vascular modulation.