中文摘要：

目的：探讨CoCl2对体外培养分化SH-SY5Y细胞的缺氧损伤保护作用及缺氧诱导基因产物VEGF在其中的作用。方法：分化的SH-SY5Y细胞随机分为对照组、化学缺氧预处理组（预处理组,细胞先用50μM CoCl2预处理3 h,换液后常氧培养1 h,然后在2%的低氧孵箱内缺氧28 h）、缺氧组（无CoCl2预处理过程,其余同预处理组）。用Western Blotting法测细胞VEGF的蛋白表达,RT-PCR测VEGF的mRNA表达,通过乳酸脱氢酶释放率和MTT细胞活力测定判断细胞损伤程度。然后,进一步通过添加VEGF单克隆抗体、重组人VEGF,验证VEGF在化学缺氧预处理组中的保护作用。结果：化学缺氧预处理组细胞VEGF蛋白、VEGF mRNA表达都显著高于缺氧组（P〈0.01）,预处理组细胞较缺氧组细胞存活率高,乳酸脱氢酶释放率减少（P〈0.01）。MTT细胞活力测定显示,40μg/ml VEGF单克隆抗体可抑制预处理的保护作用,而100 ng/ml重组人VEGF可模拟预处理组的保护作用。结论：CoCl2化学预缺氧可保护神经型细胞对缺氧产生耐受,VEGF可能在其中发挥重要的保护作用。

英文摘要：

Objective：To investigate the effects of chemical hypoxic preconditioning on neuroprotection against hypoxic injury and the roles of VEGF in differentiated SH - SY5Y cells. Methods： Differentiated SH - SY5Y cells were randomly divided into control group, chemical hypoxic preconditioning group（50μM COC12, 3 h, following 1 h normal culture, 2% 02, 28 h）and hypoxic group（2% O2, 28 h）. Western Blotting was used to examine the expression of VEGF protein,and RT - PCR was used to examine the expression of VEGF mRNA. Cell viability was evaluated by measuring lactate dehydrogenase （LDH） release and MTT assay. Further evaluation of the potential neuroprotective effect of VEGF was done by investigating the effect of recombinant human VEGF and anti - VEGF antibody on subsequent hypoxic injury. Resultst The expression of VEGF protein and VEGF mRNA increased in the preconditioning group, compared with that in the hypoxia group（P〈0. 01 ）. The preconditioned neurons had a higher survival rate and a lower lactate dehydrngenase leakage（P〈0. 01）. The effect of precondition was inhibited by with anti - VEGF antibody（40μg/ml） to blocking VEGF, and was emulated with the application of recombinant human VEGF（100ng/ml） based on MTT assay. Conclusion： CoCl2 preconditioning can protect differentiated SH - SY5Y cells from hypoxic injury and VEGF might be involved in the observed preconditioning effects.