Shear-induced increase in hydraulic conductivity in endothelial cells is mediated by a nitric oxide-dependent mechanism
Shear-induced increase in hydraulic conductivity in endothelial cells is mediated by a nitric oxide-dependent mechanism
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DOI：
10.1161/01.atv.20.1.35
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发表时间：
2000-01-01
影响因子：
8.7
通讯作者：
Tarbell, JM
中科院分区：
文献类型：
--
作者：
Chang, YS;Yaccino, JA;Tarbell, JM
本研究探讨了一氧化氮（NO）在介导多孔聚碳酸酯过滤器上生长的牛主动脉内皮细胞单层的剪切诱导的水力导电性（L(p)）增加中的作用及其下游机制。内皮单层直接暴露在20达因/厘米(2)的剪切应力下，3小时后L(p)增加4.70+/-0.20倍。剪切应力（20达因/厘米(2)）也引发了多相NO生产模式，其中快速的初始生产随后是较慢的持续生产。在没有剪切应力的情况下，外源性NO供体s -亚硝基-n -乙酰青霉胺在3小时后使内皮细胞的L(p)增加2.23+/-0.14倍（100 μ mol/L）和4.8+/-0.66倍（500 μ mol/L）。在单独的实验中，暴露于NO合成酶抑制剂N(G)-单甲基-L-精氨酸和N(G)-硝基-L-精氨酸甲酯的牛主动脉内皮细胞表现出明显的衰减，并呈剂量依赖性。LY-83,583 （1 mu mol/L）和KT5823 （1 mu mol/L）对鸟苷酸环化酶（GC）和蛋白激酶G （PKG）的抑制作用均不能减弱剪切诱导的L(p)的增加。此外，直接添加稳定的cGMP类似物8-溴-cGMP对基线L(p)没有影响，这表明GC/cGMP/PKG途径不参与剪切应力- no -L(p)反应。与碘乙酸（IAA）（一种假定的糖酵解抑制剂）孵育后，L呈剂量依赖性增加(p)。在不影响基线L(p)的水平上添加IAA大大增强了L(p)对20达因/厘米(2)剪切应力的响应。最后，剪应力诱导和iaa诱导的L(p)升高都可以随着二丁基cAMP的加入而逆转。然而，额外的代谢抑制剂，2脱氧葡萄糖（10 mmol/L）和寡霉素（1 mmol/L），或活性氧清除剂，去铁胺（1 mmol/L）和抗坏血酸（10 mmol/L），未能改变剪切诱导的L(p)增加。我们的研究结果表明，NO/cGMP/PKG途径和代谢途径都没有介导剪切应力- l (p)响应。NO下游的另一种对IAA敏感的机制必须介导这种反应。
This study addresses the role of nitric oxide (NO) and its downstream mechanism in mediating the shear-induced increase in hydraulic conductivity (L(p)) of bovine aortic endothelial cell monolayers grown on porous polycarbonate filters. Direct exposure of endothelial monolayers to 20-dyne/cm(2) shear stress induced a 4.70+/-0.20-fold increase in L(p) at the end of 3 hours. Shear stress (20 dyne/cm(2)) also elicited a multiphasic NO production pattern in which a rapid initial production was followed by a less rapid, sustained production. In the absence of shear stress, an exogenous NO donor, S-nitroso-N-acetylpenicillamine, increased endothelial L(p) 2.23+/-0.14-fold (100 mu mol/L) and 4.8+/-0.66-fold (500 mu mol/L) at the end of 3 hours. In separate experiments, bovine aortic endothelial cells exposed to NO synthase inhibitors, N(G)-monomethyl-L-arginine and N(G)-nitro-L-arginine methyl ester, exhibited significant attenuation of sheer-induced increase in L(p) in a dose-dependent manner. Inhibition of guanylate cyclase (GC) with LY-83,583 (1 mu mol/L) or protein kinase G (PKG) with KT5823 (1 mu mol/L) failed to attenuate the shear-induced increase in L(p). Furthermore, direct addition of a stable cGMP analogue, 8-bromo-cGMP, had no effect in altering baseline L(p), indicating that the GC/cGMP/PKG pathway is not involved in shear stress-NO-L(p) response. Incubation with iodoacetate (IAA), a putative inhibitor of glycolysis, dose-dependently increased L(p). Addition of IAA at levels that did not affect baseline L(p) greatly potentiated the response of L(p) to 20-dyne/cm(2) shear stress. Finally, both shear stress-induced and IAA-induced increases in L(p) could be reversed with the addition of dibutyryl cAMP. However, additional metabolic inhibitors, 2 deoxyglucose (10 mmol/L) and oligomycin (1 mu mol/L), or reactive oxygen species scavengers, deferoxamine (1 mmol/L) and ascorbate (10 mmol/L), failed to alter shear-induced increases in L(p). Our results show that neither the NO/cGMP/PKG pathway nor a metabolic pathway mediates the shear stress-L(p) response. An alternate mechanism downstream from NO that is sensitive to IAA must mediate this response.