H2S抑制Ang II引起的神经元活性氧水平升高的机制研究

摘要

AIM: To invesligale the effect of hydrogen sulfide (H2S) on the reactive oxygen species (ROS) level in medullary neurons induced by angiolensin Ⅱ ( Ang Ⅱ). METHODS: Primarily cullured rat medullary neurons were divided into 5 groups as follows; conlrol group, Ang Ⅱ group, sodium hydrosulfide(NaHS) group, NaHS with Ang Ⅱ group, and PD98059 (an inhibitor of p - ERK1/2) wilh Ang Ⅱ group. ROS production was measured wilh dihydroelhidium ( DHE) slaining. The expression of p - ERK1/2 and ERK1/2 was delermined by Weslern blolling. The aclivily of neurons was delecled by CCK -8 assay. RESULTS: Ang Ⅱ at concenlralion of 100 nmol/L significantly increased ROS level in the neurons, but the effecl was inhibited by NaHS at concentrations of 50 ~200 μmol/L, while NaHS alone had no influence on the ROS level in neurons. Additionally, PD98059 also depressed the ROS level in neurons induced by Ang Ⅱ. Furthermore , the enhanced expression of p - ERK1/2 in the neurons induced by Ang Ⅱ was significantly reduced by NaHS. CONCLUSION: H2S remarkably inhibits the ROS level in the neurons induced by Ang Ⅱ via aclivation of MAPK signal path-ways, especially p - ERK1/2, indicating that H2S rescues neurons from oxidalive stress through declining the enhanced expression of p - ERK1/2.%目的:探讨硫化氢(H2S)对血管紧张素II(angiotensin II,Ang II)所致延髓神经元活性氧(reactive oxygen species,ROS)水平变化的影响,以及H2S抗氧化应激的相关机制.方法:采用原代培养的延髓神经元,分组如下:对照组、Ang II处理组、硫氢化钠(NaHS)处理组、NaHS+Ang II处理组和PD98059(p-ERK1/2蛋白的抑制剂)+ Ang II处理组.选用二氢乙啶(DHE)荧光探针法测定各组神经元胞内的ROS水平,Western blotting检测ERK1/2和p-ERK1/2蛋白的表达量,CCK-8法测定神经元的活性.结果:Ang II(终浓度为100 nmol/L)引起神经元ROS水平升高;NaHS(50~200 μmol/L)明显抑制Ang II引起的神经元ROS水平升高,但单独给予NaHS并不影响神经元ROS水平;p-ERK1/2蛋白的抑制剂PD98059也能明显抑制Ang II引起的神经元ROS水平的升高;适宜作用浓度的NaHS能够显著降低Ang II引起的神经元p-ERK1/2蛋白表达.结论:H2S能够显著抑制Ang II引起的神经元ROS水平升高,其作用机制与MAPK家族中p-ERK1/2蛋白的表达有关.H2S可能通过降低p-ERK1/2的表达量而产生抗氧化应激作用.