蛙皮素受体亚型-3对人支气管上皮细胞的抗损伤保护作用

目的：研究蛙皮素受体亚型-3（bombesin receptor subtype-3，BRS-3）激活对人支气管上皮细胞（human brochial epithelial cells，HBECs）增殖的影响及对HBECs抗损伤的保护作用，并探讨其初步机制。方法：应用MTT法噻唑蓝3-（4，5-dimethylthiazol-2-yl）-2，5-diphenyl tetrazolium bromide]观察BRS-3特异性激动剂P3513对HBECs增殖的影响；在O3应激作用下，观察HBECs的^3H-Udr漏出率、乳酸脱氢酶释放活性、过氧化氢酶活性，以及P3513对其影响；观察P3513对HBECs上皮钙黏素（epithelial cadherin，E-cd）、整合素蛋白表达的影响。结果：（1）P3513能显著促进HBECs增殖（10^-9～10^-7mol／L），其作用呈剂量依赖性。（2）O3应激使^3H—Udr漏出率增加，LDH释放活性增加；P3513可显著降低O3应激的HBECs ^3H—Udr漏出率、LDH释放活性，但能增加过氧化氢酶活性；（3）钙调素抑制剂W7，酪氨酸激酶抑制剂PD98059和蛋白激酶A抑制剂H89能阻断P3513的促增殖和抗损伤保护效应；（4）P3513可使03应激的HBECs钙黏素、整合素蛋白的表达增强。结论：P3513介导的BRS-3激活对O3应激的HBECs有抗损伤保护作用，其信号途径可能与Ca^2＋通路、MEK和PKA有关。

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OBJECTIVE: To investigate the role and mechanism of bombesin receptor subtype 3 (BRS-3) in the proliferation and protection against injury of human brochial epithelial cells (HBECs). METHODS: Effect of P3513 (a specific agonist of BRS-3) on the proliferation of HBECs was observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method; the release rate of 3H-Udr, and LDH activity, catalase activity, and the expression of cadherin and integrin beta1 were also analyzed under O3 stress with or without P3513 treatment. RESULTS: The proliferation of HBECs was accelerated by P3513 in a concentration-dependent manner (10(-9) approximately 10(-7) mol/L). Ozone stress could promote the release rate of 3H-Udr, and LDH activity, which could be inhibited by P3513. P3513 could promote the activity of catalase. The effect of proliferation and protection against injury caused by P3513 could be inhibited by W7 (calmodulin inhibitor), PD98059 (tyrosin kinase inhibitor) and H89 (PKA inhibitor). P3513 could stimulate the expression of caderin and integrinbeta1 of ozone-stressed HBECs. CONCLUSION: Activation of BRS-3 caused by P3513 may play an important role in protecting HBECs from oxidant injury, and the signal pathway is possibly relevant to Ca2+, MEK and PKA.