JNK/SAPK和p38 SAPK-2通过半胱天冬酶-3和-9介导机械牵张诱导的NRK-52E肾上皮细胞凋亡。

JNK/SAPK and p38 SAPK-2 mediate mechanical stretch-induced apoptosis via caspase-3 and -9 in NRK-52E renal epithelial cells.

作者信息

Nguyen Hiep T, Hsieh Michael H, Gaborro Anna, Tinloy Bradford, Phillips Courtney, Adam Rosalyn M

机构信息

Department of Urology, University of California, San Francisco, California, USA.

出版信息

Nephron Exp Nephrol. 2006;102(2):e49-61. doi: 10.1159/000088401. Epub 2005 Sep 22.

DOI:10.1159/000088401

PMID:16179830

Abstract

BACKGROUND/AIMS: In renal epithelial cells, mechanical forces produced from urinary obstruction serve as potential mediators of apoptosis by activating specific intracellular signaling pathways. In this study, we sought to further define the role of JNK and p38 SAPK-2 pathway and caspase activation in stretch-induced apoptosis.

METHODS

Immortalized cell lines derived from the various components of the nephron were subjected to cyclical stretch and their differential apoptotic response was assessed. Pharmacologic inhibitors and Western blot analysis were used to assess the involvement of the MAPK pathways. Caspases' activity was assessed with ELISA and by Western blot analysis.

RESULTS

Stretch-induced apoptosis was dependent upon the cell phenotype and the degree of stretch. In NRK-52E cells, it was mediated through both JNK and p38 SAPK-2 pathways, and inhibition of either pathway reduced the degree of stretch-induced apoptosis. Stretched cells showed increased activity of caspase-3 and -9 but not -2 or -8. Stretch-induced apoptosis was modulated by inhibition of caspase-3 and to a lesser extent by caspase-9.

CONCLUSION

These findings suggest that stretch induces apoptosis in renal epithelial cells through the specific activation of JNK/SAPK and p38 SAPK-2 pathways and is dependent on the activation of caspase-3 and -9.

摘要

背景/目的：在肾上皮细胞中，尿路梗阻产生的机械力通过激活特定的细胞内信号通路，成为细胞凋亡的潜在介质。在本研究中，我们试图进一步明确JNK和p38 SAPK - 2通路以及半胱天冬酶激活在牵张诱导的细胞凋亡中的作用。

方法

对源自肾单位各组成部分的永生化细胞系进行周期性牵张，并评估其不同的凋亡反应。使用药理学抑制剂和蛋白质印迹分析来评估丝裂原活化蛋白激酶（MAPK）通路的参与情况。通过酶联免疫吸附测定（ELISA）和蛋白质印迹分析评估半胱天冬酶的活性。

结果

牵张诱导的细胞凋亡取决于细胞表型和牵张程度。在NRK - 52E细胞中，它通过JNK和p38 SAPK - 2通路介导，抑制任何一条通路均可降低牵张诱导的细胞凋亡程度。牵张处理的细胞显示半胱天冬酶 - 3和 - 9的活性增加，但半胱天冬酶 - 2或 - 8的活性未增加。牵张诱导的细胞凋亡通过抑制半胱天冬酶 - 3来调节，并且在较小程度上通过半胱天冬酶 - 9调节。