血管紧张素Ⅱ通过ROS-EGFR-JNK-AP-1信号通路诱导肾小球系膜细胞增殖

目的 探讨血管紧张素Ⅱ（AngⅡ）是否通过活性氧-表皮生长因子受体-c-Jun氨基末端激酶-活化蛋白1（ROS-EGFR-JNK-AP-1）信号通路诱导肾小球系膜细胞增殖。 方法 体外培养人肾小球系膜细胞，用AngⅡ（100 nmol/L）、葡萄糖氧化酶（GO）（1 U/L）、血管紧张素受体拮抗剂洛沙坦（10 μmol/L）、乙酰半胱氨酸（NAC，10 μmol/L）、NADPH氧化酶抑制剂apocynin（10 μmol/L）、硫酸二亚苯基碘（DPI，10 μmol/L）、EGFR阻断剂AG1478（10 μmol/L）处理细胞。以未处理细胞为阴性对照。应用3H-胸腺嘧啶（3H-TdR）掺入法和细胞计数测定系膜细胞增殖；荧光探针2,7-二氯二氢荧光素乙酰乙酸（DCFDA）检测细胞内ROS 的产生；Western 印迹检测EGFR 和JNK 活化。 结果 AngⅡ（100 nmol/L） 可显著促进肾小球系膜细胞ROS 产生，AngⅡ 刺激60 min，系膜细胞产生ROS是对照组2.26 倍。AngⅡ可呈时间和剂量依赖性诱导系膜细胞EGFR 磷酸化，AngⅡ刺激5 min，EGFR 活化明显增加，至30 min 达到高峰，随AngⅡ刺激剂量增加，EGFR活化亦显著增强，AngⅡ（100 nmol/L） 刺激30 min，EGFR 磷酸化是对照组的3.96 倍。洛沙坦、NAC以及apocynin和 DPI 显著抑制AngⅡ诱导的EGFR 磷酸化，同时AG1478 几乎完全阻断AngⅡ诱导的系膜细胞增殖；洛沙坦、NAC、apocynin、DPI 和AG1478 显著抑制AngⅡ诱导的JNK 活化。 结论 ROS-EGFR-JNK-AP-1信号通路参与AngⅡ诱导的肾小球系膜细胞增殖。NADPH 氧化酶抑制剂和EGFR 受体拮抗剂能显著抑制AngⅡ诱导的系膜细胞增殖，可能是一种新的治疗途径。

ROS-EGFR-JNK-AP-1 signaling pathway involves in angiotensin Ⅱ-induced human mesangial cells proliferation

Objective To elucidate whether Ang Ⅱ indnces the proliferation of mesangial cells through ROS-EGFR-JNK-AP-1 signaling pathway. Methods The incorporation of 3H-thymidine (3H-TdR) and cell count were used to measure mesangial cell (MC) proliferation. ROS production was determined by DCFDA fluorescence. EGFR and JNK activation was assayed by Western blot. Results Ang Ⅱ significantly enhanced ROS production in mesangial cells, which was up-regulated by 2.26 folds of control group after incubation with Ang Ⅱ for 60 min. Ang Ⅱ induced EGFR phosphorylation in dose- and time-dependent manner, with the peak (3.96 folds increase) at 30 min. EGFR phosphorylation was significantly blocked by AT1R antagonist losartan, antioxidant NAC, and NADPH oxidase inhibitor apocynin and DPI. EGFR antagonist AG1478 significantly inhibited Ang Ⅱ-induced mcsangial cell proliferation. Losartan, NAC, apocynin, DPI, and AG1478 ahnost abolished Ang Ⅱ-induced JNK activation. Conclusions ROS-EGFR-JNK-AP-1 signaling pathway is involved in Ang Ⅱ-induced mesangial cell proliferation. Apocynin and AG 1478 may be used as new therapy.