摘要目的 观察血管紧张素Ⅱ(angiotensin Ⅱ,Ang Ⅱ)对增生性瘢痕成纤维细胞磷脂酰肌醇-3激酶/蛋白激酶B(phosphoinositide 3-kinase/Akt,PI3K/Akt)信号通路的影响.方法 体外培养人增生性瘢痕成纤维细胞,用免疫荧光组织化学染色检测细胞Ang Ⅱ受体AT,和AT_2的表达.以PI3k活性测定法和Western Blotting法检测细胞PI3K的活性和Akt的磷酸化.结果 免疫荧光组织化学染色结果显示培养的增生性瘢痕成纤维细胞同表达AT_1和AT_2受体.Ang Ⅱ(10~(-9)～10~(-7)mol/L)刺激可增加细胞Akt的磷酸化和P13K的活性.AT_2受体拮抗剂PD1233191可显著增强AngⅡ诱导的细胞Akt磷酸化和PDK活性增加(P<0.05);AT_1受体拮抗剂Valsartan可显著抑制AngⅡ诱导的细胞Akt磷酸化和PDK活性增加(P<0.05).结论 Ang Ⅱ通过其受体AT_1和AT_2可调控增生性瘢痕成纤维细胞Akt磷酸化和PI3K的活性.

abstractsObjective To study the effect of angiotensin Ⅱ on phosphoinositide-3 kinase/Akt cascade in cultured fibroblasts derived from patients with hypertrophic scars. Methods The expression of AT_1 and AT_2 receptor was detected by immunofluorescence staining. Cultured human skin fibroblasts were treated with Ang Ⅱ (10~(-9)-10~(-7)mol/L), with or without an AT_1 receptor blocker, valsartan or an AT_2 receptor antagonist, PD123319. The phosphorylation of Akt was detected by western blotting, and PI3K activity was measured by Assay of PI3-K activity. Results Immunofluorescence staining showed that cultured fibroblasts derived from hypretrophic scars expressed both AT_1 and AT_2 receptors. Ang Ⅱ increased Akt phosphorylation and PI3K activity in cultured hypertrophic scar fibroblasts in a dose-and time-dependent manner. Additionally, Ang Ⅱ-induced Akt phosphorylation was blocked by wortmannin, a PI3-K inhibitor. This Ang Ⅱ-activated PI3-K/Akt cascade was significantly inhibited by valsartan, an AT_1 receptor specific blocker(P<0.05), whereas enhanced by PD123319, an AT_2 receptor antagonist (P< 0.05). Conclusion These results indicate that Ang Ⅱ receptors regulates PI3-K/Akt cascade of hypertrophic scars fibroblasts via AT_1 and AT_2.