中文摘要：

目的探讨葡萄糖降解产物甲基乙二醛（MG）对海马神经元的毒性作用及可能机制。方法取新生24h Sprague-Dawley大鼠海马神经元原代培养至第7天，给予MG干预24h，四甲基偶氮唑蓝（MTT）法检测海马神经元存活率，异硫氰酸荧光素标记的膜联蛋白V联合碘化丙啶（PI）法检测海马神经元的凋亡率，采用实时RT—PCR法及Western印迹法测定脑源性神经营养因子（BDNF）及其受体酪氨酸蛋白激酶（TrkB）mRNA和蛋白表达水平。结果 1．随着MG浓度的增加及干预时间延长，海马神经元存活率逐渐降低，呈浓度依赖性（r=0．946，P〈0．01）和时间依赖性（r=0．993，P〈0．01）。与0h组海马神经元凋亡率（1．633±0．153）％相比，100μ MMG干预2h、6h、12h和24h后，其凋亡率逐渐增加[分别为（2．833±0．153）％、（3．367±0．153）％、（4．433±0．404）％和（8．833±0．306）％；均P〈0．01]；2．与同时间对照组相比，MG干预12h组及24h组海马神经元BDNFmRNA及蛋白表达增加（P〈0．05或P〈0．01）；而MG干预6h组、12h及24h组TrkBmRNA及蛋白表达减少（P〈0．05或P〈0．01）。结论MG对海马神经元具有直接毒性作用，可能首先抑制海马神经元TrKB表达，导致BDNF表达代偿性增高，损伤BDNF-TrKB通路，诱导神经元凋亡增加。

英文摘要：

Objective To investigate the mechanisms of methylglyoxal（MG）-induced injury of hippocampal neurons. Methods Primary cultured of hippocampal neurons from 1-day-old Sprague-Dawley rats were incubated with MG for different time and dose period, Cells proliferation were assayed by methyl thiazolyl tetrazolium （MTI＇） ,and apoptosis was quantified by flow cytometer using annexin V-FITC and propidium iodide （PI） staining. The protein and mRNA levels of brain-derived neurotrophic factor （BDNF） and tyrosine kinase B （TrkB） were assayed with Western Blotting and real-time PCR. Results Treatment with MG resulted in a concentration- dependent （r = 0. 946, P 〈 0.01 ） and time-dependent （r = 0. 993, P 〈 0.01 ） decreasing neurons viability. Compared with Oh group（ 1. 633 ± 0. 153 ） % , 100 μM MG treatment for 2h ,6h, 12h and 24h ,the cellular apoptosis rate were significantly increased（（2. 833±0.153）%,（3.367 ±0. 153）%,（4.433 ±0.404）% and （8.833± 0. 306）% respectively, all P 〈 0.01 ）. MG also increased the BDNF mRNA and protein expression after 12h treatment （P 〈 0.05 or P〈 0.01 ） , but decreased the TrkB mRNA and protein expression in the cells after 6h treatlnent （P 〈 0.05 or P 〈 0. 01 ）. Conclusion MG has direct toxic effect on bippoeampal neurons and can impaire the BD- NF-TrkB signal pathway by inhibiting the expression of TrkB, and increasing the apoptosis of hippoeampal neurons.