Homer1b/c在缺氧复氧损伤神经元中的保护作用研究

Homer1b/c Neuroprotection under Hypoxia/reoxygenation-induced Neuronal Injury

目的:探讨Homer1b/c在缺氧复氧损伤神经元中的作用。方法:构建pc DNA3.1-Homer1b/c质粒和Homer1b/c si RNA,过表达及si RNA干扰Neuro-2a细胞中Homer1b/c的水平,western blot分析观察上调及下调Homer1b/c后Homer1b/c的蛋白表达变化,再予细胞缺氧复氧损伤处理,观察细胞生存率、乳酸脱氢酶(Lactic dehydrogenase,LDH)释放量及caspase-3活性的变化。结果:过表达及si RNA干扰Homer1b/c后,Homer1b/c的蛋白水平分别较正常组明显增高及降低(P值分别<0.01),提示过表达及干扰Homer1b/c的效果均明显,分别能明显提高及降低Homer1b/c的水平。在缺氧复氧损伤条件下,Homer1b/c过表达组较空质粒转染组,其细胞生存率明显增加,LDH释放量、caspase-3活性明显降低(P值分别<0.05);相反,下调Homer1b/c的水平后,与control si RNA转染组相比,细胞生存率明显降低,而LDH释放量和caspase-3活性明显增加(P值分别<0.05)。结论:Homer1b/c在缺氧复氧损伤神经元中具有神经保护作用。

Objective： To explore the role of Homerlb/c in hypoxia/reoxygenation-induced neuronal injury. Methods： The plasmids with pcDNA3.1-Homerlb/c and Homerlb/c small interfering RNA （siRNA） were constructed for over-expression and down-expression of Homerlb/c in Neuro-2a cells. Western blot analysis was determined to detect Homerlb/c protein levels after over-expression and down-expression of Homerlb/c. Cells were treated with hypoxia and reoxygenation （hypoxia/reoxygenation）. The changes in cell viability, lactic dehydrogenase （LDH） release and caspase-3 activity were observed. Results： Compared with normal control group, Homerlb/c protein levels were markedly promoted and reduced in pcDNA3.1-Homerlb/c- and Homerlb/c siRNA-transfected cells, respectively, suggesting that Homerlb/c over-expression and down-expression were able to up-regulate and down-regulate Homerlb/c expression （P value〈0.01）. Under hypoxia/reoxygenation condition, compared with pcDNA3.1-transfetcted cells, there was a significant increase in cell viability, decreases in LDH release and caspase-3 activity in Homerlb/c over-expression cells （P value〈0.05, respectively）. In contrast, compared with control siRNA-transfetcted cells, Homerlb/c down-expression group produced opposite results, characterized by a significant decrease in cell viability, increases in LDH release and caspase-3 activity （P value〈0.05, respectively）. Conclusion： Homerlb/c plays a neuroprotective role in hypoxia/reoxygenation-induced neuronal injury.