【摘要】 目的探讨脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)对高浓度谷氨酸损伤皮层神经元的保护作用及机制。方法原代培养皮层神经元细胞,通过建立谷氨酸组、BDNF组、对照组进行对照研究。AO/EB荧光染色法观察细胞凋亡形态,MTT法观察细胞凋亡率,Western blot观察p75NTR、JNK、ERK等蛋白的表达量。结果与空白对照组(1.26±0.06)相比,谷氨酸组细胞活力(0.72±0.10)显著降低(P<0.05);而与谷氨酸组比较,BDNF组(1.14±0.06)细胞活力显著提高(P<0.01)。谷氨酸组细胞凋亡比BDNF组明显增多(P<0.05)。荧光染色谷氨酸组细胞膜破坏增多。Western blot检测结果示:p75NTR表达在BDNF组(0.78±0.09)和谷氨酸组(0.90±0.18)均高于对照组(0.15±0.12)(P<0.05);JNK在BDNF组(0.56±0.16)比谷氨酸组(0.95±0.06)表达显著降低(P<0.05);而ERK在BDNF组(0.83±0.16)比谷氨酸组(0.57±0.08)表达显著升高(P<0.05),ERK在谷氨酸组中显著降低。结论 BDNF对皮层神经元细胞具有保护作用,主要通过调节p75NTR和TrkB受体之间的比例,上调ERK,下调JNK蛋白的表达来抑制凋亡,增加细胞的存活。更多还原

【Abstract】 Objective To explore the protective effect of brain-derived neurotrophic factor (BDNF) on cultured rat cortical neurons against glutamate (Glu)-induced injury and its mechanism. Methods Cortical neurons were primarily cultured from 1-day-old newborn Sprague-Dawley rats and then cultured for 7 d. The cortical neurons were divided randomly into 3 groups: control group,Glu group and BDNF group after identified with neuron-specific enolase (NSE) immunostaining. The cells of BDNF were treated with 50 ng/ml BDNF on day 6 for 24 h followed by cultured with 50 μmol/L Glu for 0.5 h. While,the cells of Glu group were cultured with 50 μmol/L Glu for 0.5 h on day 7. The control cells received no such treatments. On day 8,cell viability were determined by the colorimetric MTT assay. The morphological features of the neuron cells were observed under AO/EB fluorescence microscopy. Expressions of p75NTR,JNK and ERK were observed using Western blot analysis. Results On day 8,the primary cortical neurons grew well. BDNF protected cortical neural cells from Glu injury. Cell viability of BDNF group was (1.14±0.06),significantly higher than that of Glu group (0.72±0.10,P<0.01),though which was lower than that of the control group (1.26±0.06). More cell apoptosis was observed in Glu group than in BDNF group (P<0.05). The expression of p75NTR was higher in Glu group (0.90±0.18) and BDNF group (0.78±0.09) than in normal control group (0.15±0.12,P<0.05); the expression of JNK was lower in the BDNF group (0.56±0.16) than in the Glu group (0.95±0.06,P<0.05); at the same time,the expression of ERK was opposite to that of JNK (0.83±0.16 in the BDNF group vs 0.57±0.08 in the Glu group,P<0.05). Conclusion BDNF protects cultured rat cortical neurons from the injury induced by high-dose Glu,which may be through changing the proportion between p75NTR and TrkB,up-regulating ERK and down-regulating JNK to suppress cell apoptosis and improve cell viability.更多还原