金雀异黄素通过抑制NF—κB信号通路延缓甲状旁腺素诱导的肾间质纤维化

Genistein attenuates parathyroid hormone-induced renal interstitial fibrosis through inhibiting NF-κB signaling pathway

目的 探讨金雀异黄素（Gen）对甲状旁腺素（PTH）引起的人近曲小管上皮细胞分泌结缔组织生长因子（CTGF）的调控作用.方法 应用实时定量PCR、Western印迹、报告基因等技术,观察Gen对PTH诱导人近端肾小管上皮细胞系HK-2细胞CTGF表达的影响.采用凝胶迁移实验（EMSA）技术检测PTH刺激HK-2细胞后NF-κB的DNA结合能力;使用信号通路抑制剂阻断信号通路以明确Gen发挥作用的机制.结果 HK-2细胞有基础量的CTGF mRNA和蛋白表达,PTH刺激后其表达量显著增加（均P＜0.05）,Gen能下调PTH诱导的HK-2细胞CTGF表达.10-10 mol/L PTH作用12 h后,荧光素酶活性较对照组显著升高（1.89±0.08比0.99±0.03,P＜0.01）.正常情况下,胞核内NF-κB处于无活性状态,PTH刺激HK-2细胞后NF-κB的DNA结合能力明显增强,10-10 mol/L PTH作用30 min时NF-κB活性达到高峰.NF-κB通路抑制剂PDTC预处理HK-2细胞后,PTH诱导细胞CTGF表达较PTH组明显下降（P＜0.01）.Gen抑制PTH所致的HK-2细胞NF-κB活化.结论 Gen通过阻断NF-κB信号通路抑制PTH诱导的HK-2细胞CTGF表达从而延缓肾间质纤维化.

Objective To investigate the role of genistein （Gen） in the expression of connective tissue growth factor （CTGF） induced by parathyroid hormone （PTH） in human renal tubular epithelia cells. Methods Real-time PCR, Western blotting and reporter gene assay were employed to detect the role of Gen in PTH-induced CTGF expression in HK-2 cells. The activity of NF-κB was measured by EMSA to investigate the mechanism by which PTH induced CTGF expression in HK-2 cells. Inhibitors of NF-κB signaling pathway were used to ascertain which signal pathway was involved. Results HK-2 cells had basic amount of CTGF mRNA and protein, which, however, increased significantly after treatment with PTH, and the luciferase activity increased to a higher level as compared with control group after treatment with 10-10 mol/L PTH for 12 h （1.89±0.08 vs 0.99±0.03, P〈0.01）. Gen decreased the expressions of CTGF mRNA and protein induced by PTH in dose-dependent manner. The NF-κB of nucleus was inactivation without PTH, while the activity of NF-κB significantly increased after exposed to PTH, with the maximal response of PTH at a concentration of 10-10 mol/L and the best stimulating time at 30 minute. The NF-κB inhibitor PDTC reduced the increase of CTGF transcript levels in response to PTH stimulation. Gen blunted PTH-mediated NF-κB activation. Conclusion Gen inhibits CTGF expression induced by PTH through bloking NF-κB signaling pathway in human renal tubular epithelial cells.