ERK信号通路在右美托咪定减轻小鼠神经母细胞瘤细胞氧化应激损伤中的作用

Role of ERK signaling pathway in dexmedetomidine against mouse neuroblastoma N2a cell injury induced by oxidative stress

目的观察右美托咪定对过氧化氢(H_2O_2)所致小鼠神经母细胞瘤细胞(mouse neuroblastoma N2acells,N2a)氧化应激损伤的影响,探讨ERK信号通路的作用。方法在N2a细胞培养基中加入一定浓度的H_2O_2建立N2a细胞氧化应激损伤模型。将细胞分为五组:对照组(C组)、右美托咪定组(D组)、H_2O_2组(H组)、H_2O_2+右美托咪定组(HD组)、H_2O_2+右美托咪定+ERK抑制剂组(HDP组)。H组、HD组和HDP组给予200μmol/L的H_2O_2,HD组在H_2O_2处理前30min加入100ng/ml右美托咪定,HDP组在H_2O_2处理前30 min加入100ng/ml右美托咪定和20μmol/LERK抑制剂PD98059,D组在相应时点加入100ng/ml右美托咪定,C组给予等容量生理盐水。在H_2O_2刺激1h,检测细胞上清SOD活性,并分析ERK磷酸化水平;H_2O_2刺激4h,观察细胞生存、细胞形态学变化。结果与C组比较,H组N2a细胞生存率明显降低,细胞形态明显损伤,SOD活性明显下降(P<0.05);与H组比较,HD组的细胞生存率明显升高,细胞形态明显改善,SOD活性明显升高,ERK磷酸化水平明显增强(P<0.05);与HD组比较,HDP组细胞生存率明显降低,细胞形态明显恶化,SOD活性明显降低(P<0.05)。C组和D组细胞生存率、细胞形态、SOD活性及ERK磷酸化水平差异无统计学意义。结论右美托咪定预处理能够减轻H_2O_2所致的N2a细胞氧化应激损伤,其机制可能是通过激活细胞内ERK信号通路和提高SOD活性。

Ojective To investigate the role and underlying mechanism of dexmedetomidine in protecting mouse neuroblastoma N2a cells against oxidative stress injury, and to discuss the effect of ERK signaling pathway. Methods Na2 cell oxidative stress injury model was established by H2O2 treatment. Cells were divided into 5 groups： control group （group C）, H2O2 group （group H）, dexmedetomidine group （group D）, H2O2＋dexmedetomidine group （group HD）, H2O2＋dexmedetomidine＋ERK inhibitor group （group HDP）. Group H, group HD and group HDP were given 200 μmol/L H2O2 with or without 100 ng/ml dexmedetomidine and 20 μmol/L ERK inhibitor PD98059, group D was treated with dexmedetomidine at the corresponding point, group C was treated with equal normal saline, After 1, 4 hours of H2O2 stimulation, cell survival, morphology changes, SOD production and ERK intracellular signaling pathway were compared between groups. Results Compared to group C, N2a cells in the group H demonstrated significantly ruduced cell survival, much worse cell morphology and less SOD production （P〈0.05）. Compared to group H, N2a cells in group HD demonstrated significantly increased cell survival, much better preserved cell morphology, higher levels of SOD and enhanced ERK activation （P〈0.05）; Compared to group HD, cells in the group HDP had markedly decreased cell survival, worse cell morphology and lower SOD level （P〈0.05）. No significant changes were found in cell survival, morphology changes, SOD production and ERK intracellular signaling pathway between the groups C and D. Conclusion Dexmedetomidine protected mouse neuroblastoma N2a cells against oxidative stress injury by regulating ERK activation and SOD production.