rhEPO对预处理低氧损伤胶质细胞MMP-9表达的影响

 探讨人促红细胞生成素（rhEPO）对低氧损伤胶质细胞的影响及对金属蛋白酶-9（MMP-9）表达的影响。通过体外纯化培养第3代星形胶质细胞，将其分为正常组、低氧组、rhEPO预处理组；以四唑蓝（MTT）比色法测定低氧培养12、24、36h细胞的存活率，倒置显微镜和透射电镜观察低氧对胶质细胞形态的影响；免疫荧光和逆转录-聚合酶链反应（RT-PCR）方法研究低氧对星形胶质细胞MMP-9表达的影响。结果显示:低氧组星形胶质细胞在低氧培养下出现细胞肿胀，且随时间的延长而加重，rhEPO预处理组在各时间点细胞肿胀明显轻于低氧组。rhEPO能减轻细胞超微结构的改变及降低MTT比值。RT-PCR及免疫荧光检测表明：低氧组MMP-9 mRNA及蛋白的表达在低氧各时间点均高于正常组，在24h达到最高，在36h开始降低（P<0.05）；rhEPO预处理组MMP-9mRNA及蛋白的表达变化在12、24、36h较低氧组低（P<0.05）。由此得出结论：rhEPO通过抑制MMP-9的表达促进低氧条件下星形胶质细胞的存活。

Effect of the Recombinant Human Erythropoietin on MMP-9Expression in Astrocyte After Hypoxia Cultured

To investigation the effect of recombinant human erythropoietin preconditioning on the injury of astrocytes and the expression of MMP-9 after hypoxia, cerebral cortical astrocytes, newborn SD rat within 2 days were collected with the pure culture and the astrocytes were divided into control group, hypoxia group and rhEPO preconditioning group. The survival rate of astrocytes of 12h, 24h and 36h were determined by MTT assay. Inverted microscope and transmission electron microscope were used to observe the cell changes. The expression of MMP-9 mRNA and protein of astrocytes were detected by immunofluorescence and RT-PCR. It is shown that the astrocytes were swelled after hypoxia cultured 12h, with the maximal cell swelling observed at 36h. The rhEPO preconditioning can reduce the cell swelling remarkably. Ultrastructural alterations of astrocytes such as mitochondrial swelling after hypoxia can also be alleviated remarkably by rhEPO preconditioning. The results of MTT assay show that the survival rate of rhEPO preconditioning group were obviously higher than that of the hypoxia group(P<0.05). RT-PCR and immunocytochemistry analysis confirm that the expression of MMP-9 mRNA and protein was remarkably increased at 12h, peaked at 24h and declined at 36h after hypoxia cultured. Compared with hypoxia group, the expression of MMP-9 mRNA and protein in the rhEPO preconditioning group was significantly lower at 12h, 24h and 36h(P<0.05). The results show that rhEPO can improve the survival rate of astrocytes under hypoxia by inhibition of MMP-9.