神经节苷酯GM1对BCL-2及BDNF蛋白表达的调控在原代培养大鼠海马神经元放射性损伤防护中的意义

[目的]研究神经节苷酯GM1对原代培养大鼠海马神经元放射性损伤的保护作用及机制,为放射性脑损伤的预防提供理论依据及新的方法.[方法]30 Gy 的X射线单次照射培养至12d的海马神经元,用DAPI染核法检测海马神经元凋亡,用免疫组化法检测海马神经元BCL-2及BDNF蛋白表达情况.实验分组：0Gy组,单纯神经节苷酯GM1预处理组,30Gy组,30Gy＋神经节苷酯GM1预处理组.[结果]在照射后24 h,30Gy组核固缩百分数为（24.5±3.80）%,较0Gy组（2.00%±0.10%）有显著性差异（P〈0.01）;30Gy＋神经节苷酯GM1 100 ng/mL组核固缩百分数为（7.43±0.61）%,较30Gy组（P〈0.01）及0Gy组（P〈0.01）均有显著性差异.30Gy组海马神经元BCL-2表达阳性率为（32.89±2.82）%,较0Gy组[（93.42±2.70）%]有显著性差异（P〈0.01）,30Gy＋神经节苷酯GM1 100 ng/mL组海马神经元BCL-2表达阳性率为（77.43±0.69）%,较30Gy组（P〈0.01）及0Gy组（P〈0.01）均有显著性差异.30Gy组海马神经元BDNF表达阳性率为（88.18±3.50）%,较0Gy组[（24.28±2.96）%]有显著性差异（P〈0.01）,30Gy＋神经节苷酯GM1 100 ng/mL组海马神经元BDNF表达阳性率为（77.86±0.91）%,较30Gy组（P〈0.01）及0Gy组（P〈0.01）均有显著性差异.[结论]应用神经节苷酯GM1可以分别通过上调及下调X线照射后BCL-2及BDNF的表达而显著减少神经元的凋亡.

Significance of Ganglioside GM1 in the Protection of Radiation Injury of Hippocampal Neuron Through Regulating the Expression of BCL-2 and BDNF

[Objective]To study the protective effect of ganglioside GM1 on radiation injury of cultured rat hippocampal neuron and its mechanism in order to provide theoretic basis and new therapeutic method for preventing radiation encephalopathy. [Methods]The hippocampal neurons cultured for 12 days were subjected to a single-dose ~ray exposure of 30Gy. The 4% 6 diamidino-E-phenylindole （DAPI） staining was used to detect the apoptosis of cultured hippocampal neurons and immunohistolochemical method（IHC） was used to detect expression of BCL-2 and BDNF. All of them were divided into 0Gy group, ganglioside GMl-pretreated group, 30Gy group and 30Gy--ganglioside GMl-pretreated group. [Results] The percentage of nuclear condensation 24h after radiation in 30Gy group was （24.5±3.80）%, and had significant difference from that in 0Gy group[（2.00±0.10）%]（ P〈0.01）. The percentage of nuclear condensation 24h after radiation in 30Gy- ganglioside GM1 pretreated group was （7.43±0.61）%, and had significant difference from that in 30Gy group and 0Gy group（all P 〈0.01）. The positive rate of BCL-2 expression in hippocampal neurons in 30Gy group was （32.89±2.82） %, and had significant difference from that in 0Gy group[（93.42±2.70） %]（ P〈0.01）. The positive rate of BCL-2 expression in hippocampal neurons in 30G＋ ganglioside GM1 pretreated group was （77.43± 0.69） %, and had significant different from that in 30Gy group and 0Gy group（ P 〈0.01）. The positive rate of BDNF expression in hippocampal neurons in 30Gy group was （88.18±3.50） %, and had significant difference from that in 0Gy group[（24.28±2.96） %]（ P 〈0.01）. The positive rate of BDNF expression in hippocampal neurons in 30Gy＋ 100ng/ml ganglioside GM1 pretreated group was （77.86±0.91）%, and had significant difference from that in 30Gy group and 0Gy group（all P〈0.01）. [Conclusion] Ganglioside GM1 can significantly decrease the neuron apoptosis by up-regulating and down-regulating the expression of BCL2 and BDNF after X-ray radiation.