人参皂甙Rg1对Cdk5的调控在海马神经元放射性损伤防护中的意义

The importance of regulatory role of panaxoside Rg1 in Cdk5 on hippocampal neuron radioactive damage protection

目的 探讨人参皂甙Rg1对Cdk5的调控在海马神经元放射性损伤防护中的意义.方法 通过建立放射性脑损伤的体内模型,将40只实验大鼠按随机数字表法分为4组,每组10只,即：0Gy组（简称空白组）,单纯人参皂甙Rg1预处理组（简称对照组）,30Gy组（简称模型组）,30Gy＋人参皂甙Rg1预处理组（简称中药组）,分离、培养海马神经元,用4＇,6-二脒基-2-苯基吲哚（DAPI）染核方法检测各组海马神经元凋亡情况,采用Western blot检测p35、p25蛋白表达以及应用Cdk5抑制剂roscovitine抑制Cdk5,观察阻断Cdk5后X射线对各组海马神经元损伤的改变.结果 与空白组比较,对照组的核固缩百分数、神经元存活数目、p35、p25蛋白表达水平差异无统计学意义（P＞0.05）,模型组与中药组的核固缩百分数、p35、p25蛋白水平则明显升高,神经元存活数目明显降低,且差异有统计学意义（P＜0.05）;与模型组比较,中药组的核固缩百分数、p35、p25蛋白水平明显降低,神经元存活数目则明显升高,差异有统计学意义（P＜0.05）;单就各组＋二甲基亚砜（DMSO）而言,与空白组＋ DMSO比较,对照组＋DMSO的核固缩百分数差异无统计学意义（P＞0.05）,模型组＋DMSO与中药组＋DMSO则明显升高,差异有统计学意义（P＜0.05）;与模型组＋ DMSO比较,中药组＋DMSO的核固缩百分数明显降低,差异有统计学意义（P＜0.05）.结论 人参皂甙Rg1可通过调控Cdk5,降低神经元凋亡,而在海马神经元放射性损伤中发挥防护作用.

Objective To discuss the importance of regulatory role of panaxoside Rg1 in Cdk5 in the process of hippocampal neuron radioactive damage protection.Methods Radioactive brain damage in vivo 40 models were built,and divided into 4 groups,including 0 Gy group （short for blank group）,pure panaxoside Rg1 preconditioning group （short for control group）,30 Gy group （short for model group）,and 30Gy ＋ panaxoside Rg1 preconditioning group （short for traditional Chinese medicine group）.Hippocampal neurons were separated and trained.Hippocampal neuron apoptosis condition was tested in every group by 4′,6-diamidino2-phenylindole （DAPI） staining method.The p35 and p25 protein expressions were tested with Western blot.Cdk5 was restrained by Cdk5 restrainer roscovitine.Hippocampal neuron damage after Cdk5 blocking-up was observed with changes of X ray in every group.Results Compared with blank group,no significant difference was found in nuclear shrinkage percentage,the number of neuron survival,and the protein expression levels of p35 and p25 in control group ; nuclear shrinkage percentage and the protein expression levels of p35 and p25 were significantly increased and the number of neuron survival was significantly decreased in the model group and traditional Chinese medicine group （P 〈 0.05）.Compared with model group,nuclear shrinkage percentage and the protein expression levels of p35 and p25 were significantly decreased and the number of neuron survival was significantly increased in the traditional Chinese medicine group （P 〈 0.05）.For the addition of dimethyl sulfoxide （DMSO） in every group,the nuclear shrinkage percentage was not significantly changed in control group compared with blank group,was significantly increased in model group and traditional Chinese medicine group compared with blank group （P 〈 0.05）,and was significantly decreased in traditional Chinese medicine group compared with model group （P 〈 0.05）.Conclusions Panaxoside Rg1 can reduce neuron apoptosis by controlling Cdk5,and plays a protective role in hippocampal neuron radioactive damage.