【摘要】 目的研究缺氧诱导因子-1α(hypoxiainduciblefactor-1α,HIF-1α)在早期糖尿病大鼠视网膜中的表达,以探讨其在糖尿病性视网膜神经细胞病变发生及发展中的作用。方法用链脲佐菌素制作糖尿病大鼠模型,在制模成功后1周、2周、4周、6周、8周、10周及12周取眼球组织,以年龄匹配正常大鼠作为对照组,分别以免疫组织化学染色及Westernblotting方法检测视网膜组织中HIF-1α表达的位置及表达量;同时,以Real-timeRT-PCR方法检测视网膜组织中血管内皮细胞生长因子(vascularendothelialgrowthfac-tor,VEGF)的mRNA表达水平。结果糖尿病模型诱导成功后1周,视网膜组织即有HIF-1α表达,主要位于节细胞层及内核层的细胞核内,4周时阳性细胞数大于1周(12.34±0.41vs9.32±0.74),6~10周达到高峰(分别为16.51±0.35,45.33±0.52和37.31±0.43),12周下降(9.82±0.54)。Westernblotting显示HIF-1α蛋白表达模式与免疫组织化学相似,1周时即有表达,6~10周达到高峰,12周下降。Real-timeRT-PCR结果显示视网膜组织VEGF的mRNA水平在基础状态下少量表达,糖尿病诱导成功后表达水平逐渐提高,8周达到高峰,之后开始下降。结论HIF-1α及其下游基因VEGF在早期糖尿病视网膜神经细胞中的瞬时高表达而不是持续表达,可能是早期糖尿病视网膜神经细胞损害的原因。更多还原

【Abstract】 Objective To determine the expression of hypoxia inducible factor-1α (HIF-1α) in the retina of early stage of diabetic rats in order to understand its role in the development or maintenance of diabetic retinopathy.Methods The diabetic animal model was induced by streptozotocin.Expression of HIF-1α in the retinas of rats was analyzed 1 week,2 weeks,4 weeks,6 weeks,8 weeks,10 weeks and 12 weeks after induction of diabetes by using immunohistochemistry and Western blotting analysis.Age-matched normal rats were taken as controls.The expression of HIF-1α was measured in both controls and STZ-induced diabetic rat retinas.Meanwhile,the mRNA level of VEGF in both controls and STZ-induced diabetic rat retinas was measured by relative quantitative real-time RT-PCR.Results The expression of HIF-1α was found in the diabetic retinas as early as 1 week after induction of diabetes with immunohistochemistry,and it mainly localized in the inner nuclear and ganglion cell layers.The amount of HIF-1α-positive cells in 4-week group was larger than in 1-week group (12.34±0.41 vs 9.32±0.74),the amounts of it in 6～12 weeks group were 16.51±0.35,45.33±0.52 vs 37.31±0.43 and 9.82±0.54,respectively.There was a transient increase in the expression of HIF-1α that peaked between 6～10 weeks and declined 12 weeks after induction of diabetes.The Western blotting analysis followed a pattern similar to that of immunohistochemistry,with a transient increases being observed between 6 and 10 weeks after induction of diabetes.As to the VEGF,there was very low level of mRNA of VEGF under basic condition,after the induced of diabetes,the level increased step by step,and the peak was in 8-week,then began to subside.Conclusion The transient activation of HIF-1α and its target gene VEGF,as opposed to a more sustained effect in response to the chronic injury,may be responsible for the alterations in retinal neuron that characterize the diabetic retinopathy.更多还原