红景天苷对缺氧诱导乳鼠海马神经元凋亡的抑制作用及机制

Inhibitory effect of salidroside on apoptosis of neonatal rats' hippocampal neurons induced by hypoxia

目的探讨红景天苷对缺氧诱导乳鼠海马神经元凋亡的抑制作用及其可能的机制。方法分离培养乳鼠元代海马神经元,用免疫荧光法证实其纯度,并将其随机分为5组,正常对照组用常规培养液培养;缺氧组构建缺氧凋亡模型;红景天苷预处理组先用不同剂量(10、50、100μg/m L)红景天苷预处理24 h后构建缺氧凋亡模型。用MTT法检测海马神经元凋亡情况(细胞存活率);用相应试剂盒检测神经元培养上清液中乳酸脱氢酶(LDH)、肌酸激酶(CK)活性;用Western blotting法检测神经元中缺氧诱导因子1α(HIF-1α)蛋白表达。结果培养第5~7天,神经元纯度> 95%。与正常对照组比较,缺氧组海马神经元存活率低(P <0. 05),LDH、CK活性高(P均<0. 05);与缺氧组比较,50、100μg/m L红景天苷预处理组海马神经元存活率高(P均<0. 05),LDH、CK活性低(P均<0. 05),且呈剂量依赖性;正常对照组与100μg/m L红景天苷预处理组比较差异无统计学意义(P均> 0. 05)。与正常对照组比较,缺氧组HIF-1α蛋白相对表达量高(P <0. 05);与缺氧组比较,10、50、100μg/m L红景天苷预处理组HIF-1α蛋白相对表达量高(P均<0. 05),且呈剂量依赖性。结论红景天苷可抑制缺氧诱导的乳鼠神经元凋亡,且呈剂量依赖性;其作用机制可能与上调HIF-1α蛋白表达有关。

Objective To investigate the inhibitory effect of salidroside on hypoxia-induced apoptosis of hippocampal neurons in neonatal rats and its possible mechanism.Methods The hippocampal neurons of neonatal rats were isolated and cultured,and the purity was confirmed by immunofluorescence method.They were randomly divided into 5 groups.The control group was cultured with conventional culture medium;in the hypoxia group,we constructed the hypoxic apoptosis models;the medical groups were pretreated with different doses(10,50,and 100μg/mL)of salidroside for 24 hours,followed by hypoxia.Apoptosis of hippocampal neurons was detected by MTT colorimetry.The absorbance of each tube was measured with a spectrophotometer to calculate the activity of LDH and CK in the supernatant.Western blotting was used to detect the expression of hypoxia-inducible factor 1α(HIF-1α)protein of each group.Results On the 5th to 7th day of culture,the purity of neurons was more than 95%.Compared with the control group,the survival rate of hippocampal neurons in the hypoxia group was lower(P<0.05),and the activity of LDH and CK was higher(both P<0.05).Compared with the hypoxia group,the survival rate of hippocampal neurons in the pretreatment groups with 50 and 100μg/mL salidroside was(P<0.05),and the activity of LDH and CK was lower,with a dose-dependent manner(both P<0.05).There was no significant difference between the control group and 100μg/mL salidroside pretreatment group(P>0.05).Compared with the control group,the relative expression of HIF-1αprotein in the hypoxia group was higher(P<0.05).Furthermore,compared with the hypoxia group,the relative expression of HIF-1αprotein in the salidroside pretreatment group was relatively higher,with a dose-dependent manner(P<0.05).Conclusion Salidroside can inhibit the hypoxia-induced apoptosis of neonatal rat neurons,with a dose-dependent manner,and its mechanism may be related to the up-regulation of HIF-1αprotein expression.