Neurotensin stimulates IL-8 expression in human colonic epithelial cells through Rho GTPase-mediated NF-κB pathways
Neurotensin stimulates IL-8 expression in human colonic epithelial cells through Rho GTPase-mediated NF-κB pathways
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DOI：
10.1152/ajpcell.00328.2002
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发表时间：
2003-06-01
影响因子：
5.5
通讯作者：
Pothoulakis, C
中科院分区：
文献类型：
--
作者：
Zhao, DZ;Kuhnt-Moore, S;Pothoulakis, C
神经降压素（NT）是一种在胃肠道高表达的神经肽，参与肠道炎症的病理生理过程。我们最近发现NT通过丝裂原活化蛋白激酶（MAPK）和NF-κ B依赖性途径刺激非转化的人结肠上皮细胞NCM 460中白细胞介素-8（IL-8）的表达。然而，NT诱导促炎细胞因子如IL-8表达的分子机制尚未研究。在这项研究中，我们表明，抑制内源性Rho家族蛋白（RhoA，Rac 1和Cdc 42），其各自的显性负突变体抑制NT诱导的IL-8蛋白的产生和启动子活性。Western blot实验表明，NT强烈激活RhoA，Rac 1和Cdc 42。RhoA、Rac 1和Cdc 42的显性负突变体的过表达显著抑制NT诱导的NF-κ B依赖性报告基因表达和NF-κ B DNA结合活性。NT还刺激p38 MAPK磷酸化，RhoA，Rac 1和Cdc 42的显性负突变体的过表达并没有显着改变p38和ERK 1/2磷酸化对NT的反应。总之，我们的研究结果表明，NT刺激的IL-8表达是通过Rho依赖性NF-κ B介导的途径介导的。
Neurotensin (NT), a neuropeptide highly expressed in the gastrointestinal tract, participates in the pathophysiology of intestinal inflammation. We recently showed that NT stimulates interleukin-8 (IL-8) expression in NCM460 nontransformed human colonic epithelial cells via both mitogen-activating protein kinase ( MAPK)- and NF-kappaB-dependent pathways. However, the molecular mechanism by which NT induces expression of proinflammatory cytokines such as IL-8 has not been investigated. In this study we show that inhibition of endogenous Rho family proteins ( RhoA, Rac1, and Cdc42) by their respective dominant negative mutants inhibits NT-induced IL-8 protein production and promoter activity. Western blot experiments demonstrated that NT strongly activated RhoA, Rac1, and Cdc42. Overexpression of the dominant negative mutants of RhoA, Rac1, and Cdc42 significantly inhibited NT-induced NF-kappaB-dependent reporter gene expression and NF-kappaB DNA binding activity. NT also stimulated p38 MAPK phosphorylation, and overexpression of dominant negative mutants of RhoA, Rac1, and Cdc42 did not significantly alter p38 and ERK1/2 phosphorylation in response to NT. Together, our findings indicate that NT-stimulated IL-8 expression is mediated via a Rho-dependent NF-kappaB-mediated pathway.