Substance P stimulates cyclooxygenase-2 and prostaglandin E2 expression through JAK-STAT activation in human colonic epithelial cells
Substance P stimulates cyclooxygenase-2 and prostaglandin E2 expression through JAK-STAT activation in human colonic epithelial cells
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DOI：
10.4049/jimmunol.176.8.5050
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发表时间：
2006-04-15
影响因子：
4.4
通讯作者：
Pothoulakis, Charalabos
中科院分区：
文献类型：
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作者：
Koon, Hon-Wai;Zhao, Dezheng;Pothoulakis, Charalabos
P物质（SP）通过其神经激肽-1受体（NK-1R）调节多种胃肠功能。我们之前报道过nk - 1r介导的结肠氯化物分泌参与PG的形成。PGE(2)的生物合成由环氧化酶-1 （COX-1）和COX-2控制，其诱导涉及STATs。在这项研究中，我们检测了SP是否能刺激稳定转染人NK-1R （NCM460NK-1R细胞）的未转化的NCM460结肠细胞中PGE(2)的产生和COX-2的表达，并确定了参与这种反应的途径。SP暴露时间和剂量依赖性诱导JAK2、STAT3和STAT5的早期（1分钟）磷酸化，随后是COX-2的表达和2小时后PGE(2)的产生。药理学实验表明，PGE(2)的产生依赖于新合成的COX-2，而不是cox - 1蛋白。抑制蛋白激酶CO (PKC θ)，而不是PKC是PKC和PKC δ的一个元件，显著降低sp诱导的COX-2上调，以及JAK2、STAT3和STAT5的磷酸化。药理阻断JAK抑制sp诱导的JAK2、STAT3和STAT5磷酸化；cox - 2表达;PGE(2)生产。短暂转染JAK2短干扰RNA降低了COX-2启动子活性和JAK2磷酸化，而STAT亚型的RNA干扰表明STAT5主要介导sp诱导的COX-2启动子活性。COX-2启动子上STAT结合位点的位点定向突变完全破坏了COX-2启动子的活性。最后，在实验性结肠炎期间，小鼠结肠中COX-2的表达升高，并且通过给予NK-1R拮抗剂cj - 12255使这种作用正常化。我们的研究结果表明，SP通过激活JAK2-STAT3/5通路刺激人类结肠细胞中COX-2的表达和PGE(2)的产生。
Substance P (SP) via its neurokinin-1 receptor (NK-1R) regulates several gastrointestinal functions. We previously reported that NK-1R-mediated chloride secretion in the colon involves formation of PG. PGE(2) biosynthesis is controlled by cyclooxygenase-1 (COX-1) and COX-2, whose induction involves the STATs. In this study, we examined whether SP stimulates PGE(2) production and COX-2 expression in human nontransformed NCM460 colonocytes stably transfected with the human NK-1R (NCM460NK-1R cells) and identified the pathways involved in this response. SP exposure time and dose dependently induced an early (1-min) phosphorylation of JAK2, STAT3, and STAT5, followed by COX-2 expression and PGE(2) production by 2 h. Pharmacologic experiments showed that PGE(2) production is dependent on newly synthesized COX-2, but COX-I protein. Inhibition of protein kinase CO (PKC theta), but not PKC is an element of and PKC delta, significantly reduced SP-induced COX-2 up-regulation, and JAK2, STAT3, and STAT5 phosphorylation. Pharmacological blockade of JAK inhibited SP-induced JAK2, STAT3, and STAT5 phosphorylation; COX-2 expression; and PGE(2) production. Transient transfection with JAK2 short-interferring RNA reduced COX-2 promoter activity and JAK2 phosphorylation, while RNA interference of STAT isoforms showed that STAT5 predominantly mediates SP-induced COX-2 promoter activity. Site-directed mutation of STAT binding sites on the COX-2 promoter completely abolished COX-2 promoter activity. Lastly, COX-2 expression was elevated in colon of mice during experimental colitis, and this effect was normalized by administration of the NK-1R antagonist CJ-12,255. Our results demonstrate that SP stimulates COX-2 expression and PGE(2) production in human colonocytes via activation of the JAK2-STAT3/5 pathway.