Impairment of store-operated Ca2+ entry in TRPC4-/- mice interferes with increase in lung microvascular permeability
Impairment of store-operated Ca2+ entry in TRPC4-/- mice interferes with increase in lung microvascular permeability
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DOI：
10.1161/01.res.0000023391.40106.a8
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发表时间：
2002-07-12
影响因子：
20.1
通讯作者：
Malik, AB
中科院分区：
文献类型：
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作者：
Tiruppathi, C;Freichel, M;Malik, AB
我们研究了TRPC基因家族的推定存储操作的Ca 2+进入通道的可能性，有助于增加微血管内皮通透性，通过延长细胞内Ca 2+信号的上升。在野生型（wt）和TRPC 4敲除（TRPC 4（-/-））小鼠和从这些动物分离的肺血管内皮细胞（LEC）中进行研究。RT-PCR结果显示野生型LEC中TRPC 1、TRPC 3、TRPC 4和TRPC 6 mRNA均有表达，而TRPC 4（-/-）LEC中未检测到TRPC 4 mRNA表达。我们研究了对凝血酶的反应，因为已知凝血酶通过激活G蛋白偶联蛋白酶激活受体-1（PAR-1）来增加内皮通透性。在野生型LEC中，凝血酶或PAR-I激动剂肽（TFLLRNPNDK-NH 2）导致继发于Ca 2+内流的延长的Ca 2+瞬变。凝血酶激活的Ca ~（2+）内流可被La ~（3+）（1 μ mol/L）阻断。在TRPC 4（-/-）LEC中，凝血酶或TFLLRNPNDK-NH 2产生类似的继发于Ca 2+库耗竭的细胞内Ca 2+初始增加，但这些激动剂诱导的Ca 2+内流显著减少。TRPC 4（-/-）内皮细胞中Ca 2+内流的缺陷与缺乏凝血酶诱导的肌动蛋白应力纤维形成和内皮细胞收缩反应降低有关。在分离灌注的小鼠肺中，PAR-1激动剂肽使微血管过滤系数（K-f，K-c）（血管渗透性的量度）在wt中增加2.8倍，在TRPC 4（-/-）中增加1.4倍;在wt肺灌注液中加入La 3+（1 μ mol/L）使激动剂效应降低至在TRPC 4（-/-）中观察到的效应。这些结果表明，TRPC 4依赖的Ca 2+进入小鼠LEC是微血管通透性增加的关键决定因素。
We investigated the possibility that the TRPC gene family of putative store-operated Ca2+ entry channels contributes to the increase in microvascular endothelial permeability by prolonging the rise in intracellular Ca2+ signaling. Studies were made in wild-type (wt) and TRPC4 knockout (TRPC4(-/-)) mice and lung vascular endothelial cells (LECs) isolated from these animals. RT-PCR showed expression of TRPC1, TRPC3, TRPC4, and TRPC6 mRNA in wt LECs, but TRPC4 mRNA expression was not detected in TRPC4(-/-) LECs. We studied the response to thrombin because it is known to increase endothelial permeability by the activation of G protein-coupled proteinase-activated receptor-1 (PAR-1). In wt LECs, thrombin or PAR-I agonist peptide (TFLLRNPNDK-NH2) resulted in a prolonged Ca2+ transient secondary to influx of Ca2+. Ca2+ influx activated by thrombin was blocked by La3+ (1 mumol/L). In TRPC4(-/-) LECs, thrombin or TFLLRNPNDK-NH2, produced a similar initial increase of intracellular Ca2+ secondary to Ca2+ store depletion, but Ca2+ influx induced by these agonists was drastically reduced. The defect in Ca2+ influx in TRPC4(-/-) endothelial cells was associated with lack of thrombin-induced actin-stress fiber formation and a reduced endothelial cell retraction response. In isolated-perfused mouse lungs, the PAR-1 agonist peptide increased microvessel filtration coefficient (K-f,K-c), a measure of vascular permeability, by a factor of 2.8 in wt and 1.4 in TRPC4(-/-); La3+ (I mumol/L) addition to wt lung perfusate reduced the agonist effect to that observed in TRPC4(-/-). These results show that TRPC4-dependent Ca2+ entry in mouse LECs is a key determinant of increased microvascular permeability.