Actin filament disruption inhibits L-type Ca(2+) channel current in cultured vascular smooth muscle cells.
Actin filament disruption inhibits L-type Ca(2+) channel current in cultured vascular smooth muscle cells.
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DOI：
10.1152/ajpcell.2000.279.2.c480
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发表时间：
2000-08
期刊：
影响因子：
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通讯作者：
Mariko Nakamura;M. Sunagawa;T. Kosugi;Nicholas Sperelakis
中科院分区：
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作者：
Mariko Nakamura;M. Sunagawa;T. Kosugi;Nicholas Sperelakis
为阐明细胞骨架与血管平滑肌细胞L型Ca（2+）（Ca（L））通道活性之间的相互作用，采用全细胞电压钳技术研究了肌动蛋白丝和微管断裂对培养的血管平滑肌细胞（A7 r5细胞系）L型Ca（2+）电流[I（Ba（L））]的影响。将细胞暴露于每个破碎器1小时，然后进行电生理学和形态学检查。使用抗-α-肌动蛋白和抗-α-微管蛋白抗体的免疫染色结果显示，秋水仙素破坏肌动蛋白丝和微管，细胞松弛素D破坏只有肌动蛋白丝，和诺考达唑破坏只有微管。在暴露于秋水仙素或细胞松弛素D但不暴露于诺考达唑的细胞中，I（Ba（L））大大降低。当肌动蛋白丝被鬼笔环肽稳定或当细胞被鬼笔环肽加紫杉醇处理以稳定细胞骨架组分时，秋水仙素甚至抑制了约40%的I（Ba（L））。这些结果表明，秋水仙素也必须引起一些抑制I（Ba（L））由于另一个未知的机制，例如，Ca（L）通道的直接阻断。总之，破坏VSM细胞的肌动蛋白丝抑制Ca（L）通道活性，而破坏微管则不会。
To clarify interactions between the cytoskeleton and activity of L-type Ca(2+) (Ca(L)) channels in vascular smooth muscle (VSM) cells, we investigated the effect of disruption of actin filaments and microtubules on the L-type Ca(2+) current [I(Ba(L))] of cultured VSM cells (A7r5 cell line) using whole cell voltage clamp. The cells were exposed to each disrupter for 1 h and then examined electrophysiologically and morphologically. Results of immunostaining using anti-alpha-actin and anti-alpha-tubulin antibodies showed that colchicine disrupted both actin filaments and microtubules, cytochalasin D disrupted only actin filaments, and nocodazole disrupted only microtubules. I(Ba(L)) was greatly reduced in cells that were exposed to colchicine or cytochalasin D but not to nocodazole. Colchicine even inhibited I(Ba(L)) by about 40% when the actin filaments were stabilized by phalloidin or when the cells were treated with phalloidin plus taxol to stabilize both cytoskeletal components. These results suggest that colchicine must also cause some inhibition of I(Ba(L)) due to another unknown mechanism, e.g., a direct block of Ca(L) channels. In summary, actin filament disruption of VSM cells inhibits Ca(L) channel activity, whereas disrupting the microtubules does not.