缺氧和高糖对视网膜胶质细胞色素上皮衍生因子表达的影响

Effect of hypoxia and high glucose on expression of PEDF in cultured retinal glial cells

目的探讨缺氧和高糖对体外培养的大鼠视网膜胶质细胞色素上皮衍生因子(PEDF)表达的影响。方法采用RT-PCR和Western blot法分别对缺氧和高糖条件下大鼠视网膜胶质细胞PEDF mRNA及蛋白表达水平进行测定。结果缺氧1h、3h,PEDF表达无明显变化。缺氧6h后PEDF mRNA及蛋白表达明显下降,缺氧24h下降最明显(P<0.01)。不同浓度葡萄糖(30、40、50mmol/L)培养48h后,PEDF的表达水平均明显下降(P<0.05)。结论体外培养的大鼠视网膜胶质细胞在缺氧和高糖环境下PEDF表达明显下降。PEDF表达水平的下调可能参与了糖尿病视网膜病变新生血管的形成过程。

Objective Proliferative diabetic retinopathy（PDR） is one of the most important microvaseular complications in diabetes and a leading eause of acquired blindness. High glucose concentration and hypoxia are important factors which change the expression of the growth factors. The aim of this study was to explore the effect of hypoxia and high glucose eoneentration on the expression of pigment epithelium derived factor （PEDF） in cultured rat retinal gliai cells. Methods The retina of 20 SD rats was isolated and digested for 30 minutes. Rat glial cells were cultured in DMEM containing 20% fetal bovine serum under the hypoxic condition. 5.5 （control group） , 30,40,50 mmol/L of glucose was added in medium separately for 48 hours in glucose culture group. 200 μmol/L of CoCl2 was added 1 hour,3,6,12,24 hours respectively in hypoxic group. Cultured glial cells was identified by gliai fibrillary acidic protein （GFAP）staining. RT-PCR and Westenl-blot analysis were used to detect the levels of PEDF released by cultured glial cells at different concentrations of glucose culture group and hypoxic conditions. Results The second generation of glial cells showed the brown-yellow staining for GFAP. The PEDF level in 30,40,50 mmol/L of glucose culture groups was as 56% （ P 〈 0. 05 ） ,38% （ P 〈0. 05 ） and 14% as that of 5.5 mmol/L glucose culture group（ P 〈 0. 05 ）. The level of PEDF mRNA was 49% （ P 〈0. 05 ） ,50% （ P 〈0. 05 ） and 11% （ P 〈 0. 01 ） under the high concentration of glucose and in hypoxie for 6,12,24 hours respectively. Conclusion The PEDF expression levels in glial cells decrease under both high glucose and hypoxic condition. PEDF plays a potential role in neovascularization of diabetic retlnopathy.