环加氧酶-2在大鼠原代皮质神经细胞缺氧损伤中的作用

目的:观察环加氧酶-2(cyclooxygenase-2,COX-2)在原代培养的大鼠皮质神经细胞缺氧-再给氧损伤中的作用以及COX-2特异性抑制剂NS398的保护作用。方法: 原代培养大鼠皮质神经细胞,随机分为对照组(未处理组)、缺氧再给氧组、COX-2特异性抑制剂NS398+缺氧再给氧组。用噻唑蓝(MTT)比色法测定细胞生存率,用Western印迹法检测COX-2蛋白质的表达,用DNA凝胶电泳法检测细胞凋亡情况。结果: 培养的大鼠原代皮质神经细胞经缺氧再给氧处理后,COX-2蛋白质表达水平明显高于对照组及缺氧再给氧+NS398组(P＜0.05);缺氧再给氧+NS398予处理组神经细胞生存率明显高于单独缺氧再给氧组(P＜0.05和P＜0.01),DNA凝胶电泳显示DNA断裂显著减轻。结论:COX-2参与缺氧再给氧后神经细胞凋亡的病理过程,COX-2特异性抑制剂明显减轻缺氧再给氧后神经细胞的损伤,保护神经细胞免遭缺氧诱导的细胞凋亡。

Role of cyclooxygenase-2 in injury induced by hypoxia/reoxygenation in cultured rat cortical neurons

AIM: To observe the role of cyclooxygenase-2 (COX-2) in injury induced by hypoxia and reoxygenation in cultured rat cortical neurons and protective effects of COX-2 specific inhibitor NS398.METHODS: Primary rat cortical neuronal cells were cultured. Experiments were divided into control group, hypoxia/reoxygenation group and hypoxia/reoxygenation with COX-2 inhibitor group. Cell viability was measured by MTT assay. COX-2 protein expression was examined by Western blotting. Apoptosis was measured by DNA agarose electrophoresis.RESULTS: The expression levels of COX-2 increased significantly after neurons were treated with hypoxia and reoxygenation, compared with control group and hypoxia/reoxygenation with COX-2 inhibitor group (P<0.05). COX-2 specific inhibitor NS398 protected neurons from death (P<0.05 and P<0.01), DNA fragmentation analysis showed DNA fragmentation was inhibited significantly by NS398.CONCLUSION: COX-2 is involved in the pathogenesis of neuron apoptosis induced by hypoxia/reoxygenation. COX-2 specific inhibitor significantly protects cortical neurons against hypoxia/reoxygenation injury and inhibits apoptosis induced by hypoxia. [