亚低温治疗对神经元兴奋性毒性损伤影响的研究

摘要

目的 研究谷氨酸(Glutamate,Glu)对神经元凋亡和细胞膜损伤的影响,探讨亚低温对神经元的保护作用.方法 取孕14 d SD大鼠的胚胎脑组织培养神经干细胞.神经于细胞诱导分化6d的神经元分为37℃阴性对照组(不加入谷氨酸)、37℃阳性对照组(加入50μmol/L的谷氨酸)、29℃实验组(加入50 μmol/L的谷氨酸)；同时进行的还有31℃、33℃、35℃谷氨酸损伤模型亚低温实验组.观察Bax表达的变化,测定甘油(Glycerol,Gly)含量和培养液上清中乳酸脱氢酶(Lactate dehydrogenase,LDH)活力.结果 (1) 29℃实验组:Bax表达29℃组最高,其次为37℃阳性组,而37℃阴性组最低；培养液上清中LDH活力和Gly均为29℃组最高,其次为37℃阳性组,37℃阴性组最低；细胞中LDH活力为29℃组最低,其次为37℃阳性组,37℃阴性组最高.(2)31℃、33℃和35℃实验组:上清LDH活力、Gly和神经元Bax表达均为37℃阳性组最高,其次为31℃组、33℃和35℃实验组,37℃阴性组最低；细胞中LDH活力为37℃阳性组最低,其次为31℃组,37℃阴性组最高.结论 谷氨酸是导致神经细胞膜损伤和凋亡的原因之一；31℃～35℃亚低温治疗可以降低凋亡促进基因Bax的表达,减轻神经元细胞膜的损伤.%Objective To investigate the effect of Glutamate (Glu) on neuronal apoptosis and cell membrane damage, and analyze the protective effect of hypothermia on neurons. Methods The embryonic brain tissue from SD rats with 14 days of pregnancy were extracted and cultured for neural stem cells. After induced differentiation for 6 d, the neurons were divided into 37℃ negative control group (with no Glutamate), 37℃ positive control group (50 μmol/L Glutamate), 29℃ study group (50 μmol/L Glutamate), 31℃ study group, 33℃ study group, 35℃ study group. The expression of Bax was observed, and the content of Glycerol (Gly) as well as the activity of Lactate dehydrogenase (LDH) were investigated. Results (1) The express level of Bax was highest in the 29℃ study group, followed by the 37℃ positive control group, and lowest in the 37℃ negative control group. The activity of LDH in the culture supernatant and Gly was the highest in 29℃ study group, followed by the 37℃ positive control group, and lowest in the 37℃ negative control group. The activity of LDH in cell was the lowest in 29℃ study group, followed by the 37℃ positive control group, and the highest in the 37℃ negative control group. (2) The activity of LDH in the culture supernatant, Gly, the expression level of Bax were the highest in the 37 ℃ positive control group, followed by the 31 ℃ study group, 33 ℃ study group, 35℃ study group, and was the lowest in the 37℃ negative control group. The activity of LDH in cell was the lowest in the 37 ℃ positive control group, followed by the 31℃ study group, and was the highest in the 37 ℃ negative control group. Conclusion Glutamate is one of the main factors that lead to neuronal apoptosis and cell membrane damage. Hypothermia (31℃~35℃) can inhibit apoptosis and cell membrane damage, and promote the expression of Bax.