Cholesterol depletion impairs vascular reactivity to endothelin-1 by reducing store-operated Ca2+ entry dependent on TRPC1
Cholesterol depletion impairs vascular reactivity to endothelin-1 by reducing store-operated Ca2+ entry dependent on TRPC1
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DOI：
10.1161/01.res.0000100367.45446.a3
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发表时间：
2003-10-31
影响因子：
20.1
通讯作者：
Swärd, K
中科院分区：
文献类型：
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作者：
Bergdahl, A;Gomez, MF;Swärd, K
血管壁对内皮素-1(ET-1)的反应性受到胆固醇的影响，这可能在动脉粥样硬化的进展中起着重要作用。为了阐明影响信号转导的步骤，我们用胆固醇受体甲基-β-环糊精(mbetacd，10 mmoL/L)来操纵膜胆固醇并破坏完整大鼠动脉的小凹。在去内皮尾动脉上，mbetacd可降低血管对10nmol/L ET-1的收缩反应，而胆固醇则可增强其收缩反应。Mbetacd不影响ETA和小窝蛋白-1的配基结合和共定位。从Mn2+猝灭率和细胞内[Ca~(2+)]反应来看，美倍他丁治疗的尾动脉在耗尽细胞内Ca~(2+)贮备库后，通过储备室操作的通道减少了Ca~(2+)内流。逆转录-聚合酶链式反应检测TRPC1、3和6的表达，免疫荧光显示mbetacd可减少TRPC1与小窝蛋白-1的共存。对ET-1的部分收缩反应可被Ni2+(0.5 mmol/L)和TRPC1封闭抗体所抑制。在基底动脉中，ET-1引起的收缩对TRPC1阻断抗体和mbetacd不敏感，因为它比尾动脉表现出更少的储藏操作通道活动。器官培养后基底动脉储备操作通道活动增加与ET-1收缩对mbetacd敏感性增加相关。这些结果表明，胆固醇通过影响TRPC1的空泡定位来影响血管对ET-1的反应性。
The reactivity of the vascular wall to endothelin-1 (ET-1) is influenced by cholesterol, which is of possible importance for the progression of atherosclerosis. To elucidate signaling steps affected, the cholesterol acceptor methyl-beta-cyclodextrin (mbetacd, 10 mmol/L) was used to manipulate membrane cholesterol and disrupt caveolae in intact rat arteries. In endothelium-denuded caudal artery, contractile responsiveness to 10 nmol/L ET-1 (mediated by the ETA receptor) was reduced by mbetacd and increased by cholesterol. Neither ligand binding nor colocalization of ETA and caveolin-1 was affected by mbetacd. Ca2+ inflow via store-operated channels after depletion of intracellular Ca2+ stores was reduced in mbetacd-treated caudal arteries, as shown by Mn2+ quench rate and intracellular [Ca2+] response. Expression of TRPC1, 3, and 6 was detected by reverse transcriptase-polymerase chain reaction, and colocalization of TRPC1 with caveolin-1 was reduced by mbetacd, as seen by immunofluorescence. Part of the contractile response to ET-1 was inhibited by Ni2+ (0.5 mmol/L) and by a TRPC1 blocking antibody. In the basilar artery, exhibiting less store-operated channel activity than the caudal artery, ET-1-induced contractions were insensitive to the TRPC1 blocking antibody and to mbetacd. Increased store-operated channel activity in basilar arteries after organ culture correlated with increased sensitivity of ET-1 contraction to mbetacd. These results suggest that cholesterol influences vascular reactivity to ET-1 by affecting the caveolar localization of TRPC1.