一氧化氮诱导海马神经元凋亡信号通路的研究

目的 研究神经元缺血-再灌注时诱导型一氧化氮合酶(iNOS)源性一氧化氮(NO)诱导神经元凋亡的信号转导通路.方法 培养7 d的大鼠海马神经元随机分为四组:正常培养组(A组)神经元按正常培养方法培养;缺血一再灌注组(B组)神经元进行缺糖缺氧后复糖复氧处理;缺血一再灌注 1400W(iNOS抑制药)组(C组)和缺血一再灌注 U-0126(ERK抑制药)组(D组)神经元进行缺糖同时分别加入1400W或U-0126,使其终浓度均为10 μM后同B组处理.进行神经元纯度鉴定,检测神经元存活率、神经元凋亡率、NO、cGMP、iNOS-mRNA表达、ERKl/2和P90RSK蛋白表达.结果 与A组比较,B组大鼠海马中NO、cGMP、iNOS-mRNA、ERK1/2、P90RSK增高,神经元存活率降低、凋亡率升高(P＜0.01).与B组比较,C组大鼠海马中NO、cGMP、iNOS-mRNA、ERK1/2和P90RSK降低,神经元存活率升高、凋亡率降低(P＜0.01);D组大鼠海马中NO、cGMP和iNOS-mRNA变化不明显但ERK1/2和P90RSK降低,神经元存活率升高、凋亡率降低(P＜0.01).结论 神经元缺血-再灌注损伤时,iNOS源性的NO通过cGMP介导ERK1/2/P90RSK信号转导通路诱导神经元的凋亡.

Nitric oxide mediating kinase signal pathway involves in hippocampus neuron ischemia-reperfusion injury

Objective To investigate the role of cell signal pathway in NO-induced apoptosis after neuron ischemia-reperfusion(I/R) injury.Methods The neuron cells from Wistar rets hippocampus were cultured for 7 days and divided into 4 groups.The cells in group A were treated with a conventional culture way as the controls.The cells in group B were treated with oxygen glucose deprivation(OGD).The cells in group C were treated with 1 400 W(an inhibitor of inducible nitric oxide synthase,iNOS),and those in group D with U-0126 10 M during OGD.Neuron viability and apoptosis,concentrations of NO and cGMP were measured.The expression of iNOS-mRNA,ERK1/2 and P90RSK protein were detected.Results Compared with group A,NO,cGMP,iNOS-mRNA,ERK1/2 and P90RSK increased,neuron viability decreased and neuron apoptosis increased in group B(P<0.01).Compared with group B,NO,cGMP,iNOS-mRNA,ERK1/2,P90RSK and neuron apoptosis decreased,neuron viability increased in group C(P<0.01),and ERK1/2,P90RSK and neuron apoptosis decreased,neuron viability increased,but NO,cGMP and iNOS-mRNA were not significantly changed in group D(P<0.01).Conclusion NO induces neuron apoptosis after I/R through cGMP activating ERK/P90RSK cell signal pathway.