丙泊酚后处理对氧糖剥夺胎鼠海马神经元ADAR2-AMPA受体GluR2通路的影响

Effect of propofol post-conditioning on ADAR2-AMPA receptor GluR2 pathway in hippocampal neurons of fetal rats subjected to oxygen-glucose deprivation

目的 探讨丙泊酚后处理对氧糖剥夺胎鼠海马神经元腺苷脱氨酶（ADAR2）-α-氨基-3-羟基-5-甲基-4-异恶唑丙酸（AMPA）受体GluR2通路的影响.方法 原代培养孕16- 18 d Wistar大鼠胎鼠海马神经元7d,采用随机数字表法分为3组（n=6）：对照组（C组）、氧糖剥夺组（O组）和丙泊酚后处理组（P组）.C组正常培养;O组缺氧、缺糖1h后复糖、复氧;P组缺氧、缺糖1h后复糖、复氧即刻加入丙泊酚1.2 μg/ml孵育2h,随后更换正常培养液进行培养.于培养24 h时收集细胞,采用MTT法检测海马神经元存活情况,采用RT-PCR法检测ADAR2mRNA的表达,Western blot法检测总ADAR2蛋白（tADAR2）及胞核ADAR2蛋白（nADAR2）的表达,巢式RT-PCR和特异性限制性内切酶BbV1法检测ADAR2受体GluR2 mRNA Q/R位点编辑比例.结果 3组海马神经元ADAR2mRNA及总ADAR2蛋白表达差异无统计学意义（P＞0.05）;与C组比较,O组海马神经元存活率下降,胞核ADAR2蛋白表达下调,海马神经元胞核ADAR2/总ADAR2蛋白比值下降,GluR2 mRNA Q/R位点编辑比例下降（P＜0.05）;与O组比较,P组海马神经元存活率上升,胞核ADAR2蛋白表达上调,海马神经元胞核ADAR2/总ADAR2蛋白比值升高,GluR2 mRNA Q/R位点编辑比例升高（P＜0.05）.结论 丙泊酚后处理可通过激活ADAR2-AMPA受体GluR2通路减轻胎鼠氧糖剥夺海马神经元损伤.

Objective To investigate the effect of propofol post-conditioning on RNA2 （ADAR2）-α-amino-3-hydroxy-5-methyliso xazole-4-propionic acid （AMPA） receptor subunit glutamate 2 （GluR2） pathway in hippocampal neurons of fetal rats subjected to oxygen-glucose deprivation （OGD）.Methods The hippocampal neurons were isolated from the fetal rats obtained from Wistar rats at 16-18 days of gestation and primarily cultured for 7 days.The primarily cultured neurons were randomly divided into 3 groups （n =6 each）：control group （group C） ; OGD group （group O） ; propofol post-conditioning group （group P）.The cells were subjected to OGD for 1 h followed by restoration of O2-glucose supply in group O.In group P,the cells were subjected to OGD for 1 h followed by restoration of O2-glucose supply and then 1.2 μg/ml propofol was added and the cells were cultured for 2 h and then the culture medium was replaced with plain culture medium.At 24 h of incubation,the cells were collected for assessement of the survival rates of the hippocampal neurons and for determination of the expression of ADAR2 mRNA （by RT-PCR）,the total ADAR2 protein （tADAR2） and ADAR2 protein in the nucleus of cells （nADAR2） （by Western bolt）.The editing percentage of GluR mRNA at the Q/R site was analyzed by nest RT-PCR and BbV1.Results There was no significant difference in the expression of ADAR2 mRNA and tADAR2 among the three groups.Compared with group C,the survival rates of the hippocampal neurons were significantly decreased,the expression of nADAR2 was down-regulated,the ratio of nADAR2/tADAR2 was decreased,and the editing percentage of GluR mRNA at the Q/R site was decreased in group O.Compared with group O,the survival rates of the hippocampal neurons were significantly increased,the expression of nADAR2 was up-regulated,the ratio of nADAR2/tADAR2 was increased,and the editing percentage of GluR mRNA at the Q/R site was increased in group P.Conclusion Propofol post-conditioning reduces OGD-induced damage to hippocampal neurons of fetal rats through activating ADAR2-AMPA receptor GluR2 pathway.