α-Melanocyte-Stimulating Hormone Inhibits Tumor Necrosis Factor α-Stimulated MUC5AC Expression in Human Nasal Epithelial Cells
α-Melanocyte-Stimulating Hormone Inhibits Tumor Necrosis Factor α-Stimulated MUC5AC Expression in Human Nasal Epithelial Cells
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DOI：
10.1165/rcmb.2009-0420oc
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发表时间：
2011-05-01
影响因子：
6.4
通讯作者：
Yoon, Joo-Heon
中科院分区：
文献类型：
--
作者：
Lee, Sang-Nam;Ryu, Ji-Hwan;Yoon, Joo-Heon
粘蛋白高分泌是几种呼吸系统疾病的重要临床特征，包括哮喘、囊性纤维化、鼻过敏、鼻炎和鼻窦炎。已有研究表明，α-黑素细胞刺激素(α-MSH)是一种由前阿片黑素皮质素(POMC)衍生的多肽，它通过抑制促炎细胞因子如TNF-α诱导的核因子-kappaB的激活而具有免疫调节活性。由于已知的MUC5AC基因表达是由肿瘤坏死因子-α通过激活核因子-kappaB来上调的，因此我们评价了α-MSH对肿瘤坏死因子-α诱导的正常人鼻上皮(NHNE)细胞MUC5AC基因表达的抑制作用。采用RT-PCR、Western blotting和免疫荧光标记等方法检测NHNE细胞黑素皮质素-1受体(MC-1R)的表达。Western blotting结果显示，α-MSH以剂量依赖的方式抑制肿瘤坏死因子-α诱导的核因子-kappaB/p65的磷酸化和IKB-α的降解。此外，α-MSH还能抑制肿瘤坏死因子-α诱导的核因子-kappaB的核转位和核因子-kappaB荧光素酶的活性。实时定量聚合酶链式反应结果显示，α-MSH可抑制肿瘤坏死因子α诱导的MUC5AC的表达，这种作用可被MC-1R shRNA慢病毒敲除MC-1R所抵消。RT-PCR和Western blotting分析表明，POMC和POMC加工过程中的两个关键酶--原蛋白转换酶(PC)1和PC2，以及PC2的酶活性所必需的7B2在正常鼻黏膜中都有表达。我们的结论是，α-MSH通过MC-1R刺激抑制肿瘤坏死因子-α诱导的NHNE细胞的核因子-kappaB活性，从而下调MUC5AC的表达，正常人鼻粘膜具有POMC加工机制。因此，α-MSH可能是减少由核因子-kappaB激活引起的粘蛋白过度产生的一个有前景的候选药物。
Mucin hypersecretion is an important clinical feature of several respiratory diseases, including asthma, cystic fibrosis, nasal allergy, rhinitis, and sinusitis. It has been shown that alpha-melanocyte-stimulating hormone (alpha-MSH), a proopiomelanocortin (POMC)-derived peptide, has immunomodulatory activities by inhibiting NF-kappa B activation induced by proinflammatory cytokines such as TNF-alpha. Because MUC5AC expression is known to be up-regulated by TNF-alpha via NF-kappa B activation, we evaluated the inhibitory effect of alpha-MSH on MUC5AC gene expression induced by TNF-alpha in normal human nasal epithelial (NHNE) cells. Melanocortin-1-receptor (MC-1R) was detected by RT-PCR, Western blotting, and immunofluorescent labeling in NHNE cells. alpha-MSH suppressed NF-kappa B/p65 phosphorylation induced by TNF-alpha as well as IkB-alpha degradation in a dose-dependent manner, as assessed by Western blotting. In addition, alpha-MSH inhibited TNF-alpha-induced nuclear translocation of NF-kappa B and NF-kappa B luciferase activity. Real-time quantitative PCR data showed that alpha-MSH inhibited TNF-alpha-induced expression of MUC5AC, and this effect of alpha-MSH was neutralized by knockdown of MC-1R using MC-1R shRNA lentivirus. Analyses using RT-PCR and Western blotting showed the expression of POMC and two key enzymes in the POMC processing, proprotein convertases (PC) 1 and PC2, and 7B2, which is required for enzymatic activity of PC2, in normal human nasal mucosa. We conclude that alpha-MSH down-regulates MUC5AC expression by inhibiting TNF-alpha-induced NF-kappa B activity through MC-1R stimulation in NHNE cells and that normal human nasal mucosa possesses the POMC processing machinery. Therefore, alpha-MSH may be a promising candidate to decrease mucin overproduction initiated by NF-kappa B activation.