Ca2+ signalling and PKCα activate increased endothelial permeability by disassembly of VE-cadherin junctions
Ca2+ signalling and PKCα activate increased endothelial permeability by disassembly of VE-cadherin junctions
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DOI：
10.1111/j.1469-7793.2001.0433a.x
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发表时间：
2001-06-01
影响因子：
5.5
通讯作者：
Tiruppathi, C
中科院分区：
文献类型：
--
作者：
Sandoval, R;Malik, AB;Tiruppathi, C
1.研究了细胞内Ca 2+动员在内皮通透性增加机制中的作用。将人脐静脉内皮细胞（HUVEC）暴露于毒胡萝卜素或凝血酶，其浓度导致细胞内Ca 2+浓度（[Ca 2 +]（i））类似增加。在这两种情况下，[Ca 2 +]（i）的升高是由于细胞内储存的Ca 2+的释放和细胞外Ca 2+的流入。两种药物均降低了内皮细胞单层电阻（内皮细胞形状变化的测量），并增加了跨内皮I-125-白蛋白渗透性。毒胡萝卜素诱导激活PKC α和VE-钙粘蛋白连接的不连续性，而不形成肌动蛋白应力纤维。凝血酶也诱导PKC α激活和VE-钙粘蛋白连接的类似改变，但与肌动蛋白应力纤维形成相关。毒胡萝卜素未能促进20 kDa肌球蛋白轻链（MLC 20）的磷酸化，而凝血酶诱导MLC 20磷酸化，这与肌动蛋白应激过滤器的形成一致。4. Calphostin C预处理防止了VE-钙粘蛋白连接的破坏和由两种药物引起的跨内皮电阻的降低。因此，由毒胡萝卜素和凝血酶引起的[Ca 2 +]（i）增加可能激活钙磷蛋白C敏感的PKC通路，该通路发出VE-钙粘蛋白连接解体和增加内皮渗透性的信号。结果表明，Ca 2+信号传导和PKC α的激活在介导VE-钙粘蛋白连接的破坏中起关键作用，从而在内皮通透性增加的机制中起关键作用。
1. The role of intracellular Ca2+ mobilization in the mechanism of increased endothelial permeability was studied. Human umbilical vein endothelial cells (HUVECs) were exposed to thapsigargin or thrombin at concentrations that resulted in similar increases in intracellular Ca2+ concentration ([Ca2+](i)). The rise in [Ca2+](i) in both cases was due to release of Ca2+ from intracellular stores and influx of extracellular Ca2+.2. Both agents decreased endothelial cell monolayer electrical resistance (a measure of endothelial cell shape change) and increased transendothelial I-125-albumin permeability. Thapsigargin induced activation of PKC alpha and discontinuities in VE-cadherin junctions without formation of actin stress fibres. Thrombin also induced PKC alpha activation and similar alterations in VE-cadherin junctions, but in association with actin stress fibre formation.3. Thapsigargin failed to promote phosphorylation of the 20 kDa myosin light chain (MLC20), whereas thrombin induced MLC20 phosphorylation consistent with formation of actin stress filters.4. Calphostin C pretreatment prevented the disruption of VE-cadherin junctions and the decrease in transendothelial electrical resistance caused by both agents. Thus, the increased [Ca2+](i) elicited by thapsigargin and thrombin may activate a calphostin C-sensitive PKC pathway that signals VE-cadherin junctional disassembly and increased endothelial permeability.5. Results suggest a critical role for Ca2+ signalling and activation of PKC alpha in mediating the disruption of VE-cadherin junctions, and thereby in the mechanism of increased endothelial permeability.