Ang Ⅱ诱导大鼠原代海马神经细胞衰老的作用及机制

Role of angiotensin Ⅱ inducing cell senescence in rat hippocampal neurons in primary culture

目的探讨血管紧张素Ⅱ(AngⅡ)诱导大鼠原代海马神经细胞衰老的作用及相关机制。方法从新生24 h内的乳鼠取材,培养大鼠原代海马神经细胞。采用不同浓度诱导剂AngⅡ和不同诱导时间两种方法处理神经细胞,通过衰老相关β-半乳糖苷酶(SA-β-gal)染色法检测神经细胞衰老情况,确定AngⅡ诱导神经细胞衰老的最佳浓度和时间。进一步采用SA-β-gal染色法检测AT1受体阻断剂厄贝沙坦和AT2受体阻断剂PD123319对AngⅡ诱导神经细胞衰老的影响,同时利用Western blot法检测细胞周期调控相关蛋白P53、P21的表达变化,探讨AngⅡ诱导神经细胞衰老的相关机制。结果 10μmol/L AngⅡ作用48 h可诱导大鼠原代海马神经细胞衰老,细胞内P53、P21等蛋白表达增加。厄贝沙坦可抑制AngⅡ所致神经细胞衰老,降低P53、P21等蛋白表达,而PD123319对此无作用。结论 AngⅡ可诱导大鼠原代海马神经细胞衰老,此作用由AT1受体介导,其机制可能与P53、P21表达增加有关。

Objective To investigate the effect and related mechanism of angiotensin Ⅱ（ Ang Ⅱ ） inducing cell senescence in rat hippocampal neurons in primary culture. Methods Primary neonatal rat hippocampal neurons were cultured. Senescence-associated β-galactosidase （ SA-β-gal） staining was used to detect cell senescence induced by Ang II in different concentrations and at different time to determine the best inducing condition. To further explore the mechaisms, the effects of AT receptor blocker irbesartan and AT2 receptor blocker PD123319 on Ang Ⅱ -induced cell senescence were examined. Expressions of cell cycle-related protein P53 and P21 were detected by Western blot assay. Results Fortyight his incubation of Ang Ⅱ （ 10 μmol/L） could induce cell senescence in primary rat hippocampal neurons. Irbesartan could inhibit cell senescence induced by Ang Ⅱand reduce the expression of P53 and P21, whereas PD123319 had no effect on both of them. Conclusion Ang IT can induce cell senescence in the primary rat hippocampal neurons. The effect of Ang Ⅱ on cell senescence may be mediated by AT1 receptor and the mechanism may be related to the over-expression of protein P53 and P21.