Modulation of renal epithelial barrier function by mitogen-activated protein kinases (MAPKs): Mechanism of cyclosporine A-induced increase in transepithelial resistance
Modulation of renal epithelial barrier function by mitogen-activated protein kinases (MAPKs): Mechanism of cyclosporine A-induced increase in transepithelial resistance
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DOI：
10.1046/j.1523-1755.2003.00804.x
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发表时间：
2003-03-01
影响因子：
19.6
通讯作者：
Ryan, MP
中科院分区：
文献类型：
--
作者：
Kiely, B;Feldman, G;Ryan, MP
背景资料。环孢素A(CsA)可增加狗肾(MDCK)细胞的跨上皮阻力，其机制可能与连接蛋白的磷酸化有关。在这项研究中，我们研究了细胞外信号调节蛋白激酶(ERK)1/2和p38丝裂原活化蛋白激酶(MAPK)通路对基础跨上皮阻力(TER)和环孢素A(CsA)诱导的跨MDCK单层TER增加的影响。在这里，我们提出了CsA可能通过激活ERK 1/2 MAPK通路来调节其某些效应的证据。用CsA(4.2mumol/L)处理MDCK细胞，用TER法测定细胞旁通透性。使用ERK 1/2的抑制剂PD98059和U0126以及p38的抑制剂SB203580，研究ERK 1/2和p38 MAPK通路在TER调控中的作用。Western印迹分析检测ERK1/2和p38的磷酸化/活化。环孢素A(4.2mumol/L)可增加mDCK单层TER。ERK1/2抑制剂PD98059可降低基础TER，也可改善CsA诱导的TER升高。P38抑制剂SB203580对单层细胞的基础TER无影响，但SB203580可显著增强CsA诱导的TER升高。CsA可显著激活ERK1/2，PD98059可阻止CsA激活ERK1/2。SB203580抑制p38通路也可激活ERK1/2，CsA可进一步增强ERK1/2的激活。结论CsA及其抑制剂PD98059或SB203580对p38的磷酸化无明显影响。这些结果表明，ERK 1/2 MAPK级联信号通路的激活在调节MDCK细胞的细胞旁通透性中起重要作用。该通路的激活似乎在CsA诱导的TER增加中起着关键作用。
Background. Cyclosporine A (CsA) has been shown to increase transepithelial resistance in Madin-Darby canine kidney (MDCK) cells, and the mechanism may involve altered phosphorylation of junctional proteins. In this study, we examine the effect of the extracellular signal-regulated protein kinase (ERK) 1/2 and p38 mitogen-activated protein kinase (MAPK) pathways on the basal transepithelial resistance (TER) and on the CsA-induced increase in TER across MDCK monolayers. Here we present evidence that CsA may be mediating some of its effects through activation of the ERK 1/2 MAPK pathway.Methods. MDCK cells were treated with CsA (4.2 mumol/L) and paracellular permeability was assessed by measuring TER. The role of the ERK 1/2 and the p38 MAPK pathways in modulating TER was investigated using the inhibitors PD98059 and U0126 for ERK 1/2 and SB203580 for p38. ERK 1/2 and p38 phosphorylation/activation was also examined by Western blot analysis.Results. CsA (4.2 mumol/L) increased the TER of MDCK monolayers. The ERK 1/2 inhibitor PD98059 decreased basal TER and also ameliorated the CsA-induced increase in TER. Similar results were found with the U0126 inhibitor of ERK 1/2. The p38 inhibitor SB203580 had no effect on the basal TER of the monolayers, however, SB203580 significantly augmented the CsA-induced increase in TER. CsA was shown to significantly activate ERK 1/2 and this activation by CsA was prevented by PD98059. Inhibition of the p38 pathway by SB203580 also resulted in activation of ERK 1/2 and this activation of ERK 1/2 was further enhanced by CsA. No effect of CsA or the inhibitors PD98059 or SB203580 on p38 phosphorylation was detected.Conclusion. The results presented here suggest that activation of the ERK 1/2 MAPK cascade is important in the regulation of the paracellular permeability in MDCK cells. Activation of this pathway appears to be pivotal to the CsA-induced increase in TER.