低氧预适应对新生大鼠视网膜神经元谷氨酸损伤的保护作用

Protection of hypoxic preconditioning on retinal neurons injury of neonatal rat induced by glutamic acid

目的探讨低氧预适应对大鼠视网膜神经元谷氨酸损伤的保护作用。方法建立视网膜神经元低氧预适应模型和谷氨酸损伤模型。Westernblot、免疫荧光检测低氧预适应后不同时段HIF-1α、EPO蛋白表达情况;MTT比色法评价正常对照组、低氧预适应组、谷氨酸组、低氧谷氨酸组神经元活力改变。结果低氧预适应后HIF-1α、EPO蛋白表达一过性增高。免疫荧光染色显示低氧预适应后神经元呈现HIF-1α、EPO蛋白的阳性表达。MTT法测定细胞活力结果显示,视网膜神经元经谷氨酸损伤后细胞活性降低,而低氧谷氨酸组细胞活性显著高于谷氨酸组(P<0.01)。结论低氧预适应能够上调神经元HIF-1α、EPO蛋白的表达,从而增强神经元对谷氨酸损伤的耐受能力,起到神经保护作用。

Objective To expose to a low oxygen environment can be used as a preconditioning paradigm to protect cells or tissues in the brain. It had the same effect in retinal degeneration. We investigated the effects of hypoxic preconditioning on retinal neuroprotection in neonatal rat induced by glutamic acid. Methods Neuronal cells from retina of neonatal rat were exposed to CoCl2 for 24 hours to develop hypoxic preconditioning and injury model of glutamic acid. The expressions of hypoxia-inducible factor-lot （HIF-lot）and erythropoietin （EPO）were detected with Western blot and immunofluorescence after hypoxic preconditioning. MTT assay was applied to detect cells viability in hypoxic preconditioning group, glutamic acid group, hypoxic glutamic acid group and normal control group. Results Western blot and immunofluorescence assay indicated that the expressions of HIF-1 ot and EPO were elevated after hypoxic preconditioning,but no positive expression was seen in normal neuron cells. MTT assay revealed that the viability of retinal neuronal cells of rat decreased in glutamic acid injured group. Cellular viability in hypoxic glutamic acid group was apparently higher than that in glutamic acid group （ P 〈 0.01 ）. Conclusion Hypoxic preconditioning could improve the injure tolerance induced by glutamic acid in retinal neuronal cells of rats through the increase the expression of HIF-lot and EPO.