TGF-β介导的Smad信号通路在增生型糖尿病视网膜病变中的作用和意义

Role and significance of TGF-β mediated Smad signaling pathways in proliferative diabetic retinopathy

目的本研究旨在观察转化生长因子β(transforming growth factor-beta,TGF-β)介导的Smad信号通路在增生型糖尿病视网膜病变(proliferative diabetic retinopathy,PDR)中的作用和意义,进而阐明其可能的发病机制。方法收集正常人和糖尿病患者的血液标本,将糖尿病患者依据视网膜受累程度分为2组:无糖尿病视网膜病变(non-diabetic retinopathy,NDR)组、糖尿病视网膜病变(diabetic retinopathy,DR)组,根据眼底改变又分为非增生型糖尿病视网膜病变(non-proliferative diabetic retinopathy,NPDR)组和增生型糖尿病视网膜病变(proliferative diabetic retinopathy,PDR)组。分别用ELISA检测正常人和糖尿病患者血浆中的TGF-β1和TGF-β2,Western blot检测血浆中TGF-β1、TGF-β2、Smad3和pSmad3的蛋白表达量,比较各组差异。结果与对照组比较,糖尿病患者各组TGF-β1和TGF-β2分泌量和TGF-β1、TGF-β2、p-Smad3的蛋白表达量均明显升高(均为P<0.05);与NDR组比较,DR各组上述指标均显著增高(均为P<0.05);PDR组上述指标均显著高于NPDR组(均为P<0.05)。结论 TGF-β介导的Smad信号通路参与了DR的发生,可能是介导PDR发生的重要机制。

Objective To observe the role and significance of transforming growth factor-β （TGF-β） mediated Smad signaling pathways in the proliferative diabet- ic retinopathy（ PDR）, and illustrate its possible pathogenesis. Methods Diabetic pa- tients were divided into two groups on the basis of the retinal involvement degree： Non- diabetic retinopathy （NDR）, diabetic retinopathy （DR）. According to retina changes, DR were divided into two subtypet ：Non-proliferative diabetic retinopathy（NPDR） ,pro- liferative diabetic retinopathy （PDR）. The blood samples from normal people and dia- betic patients were detected to analyze secretion level of TGF-β1 and TGF-β2 by ELISA and the protein expression level of TGF-β1, TGF-β2, Smad3 ,p-Smad3 by Western blot in serum. Results Compared with normal group, the secretion and relative protein ex- pression of TGF-β1, TGF- β2 were significantly higher in diabetic patients （ all P 〈 0.05）, the relative protein expression of p-Smad3 was also clearly higher in diabetic patients （ all P 〈 0.05 ） ; Compared with NDR, the results were similar （ all P 〈 0.05 ） ; Subgroup a- nalysis showed that the above indexes were significantly higher in PDR than NPDR pa- tients （ all P 〈 0.05 ）. Conclusion TGF-β mediated Smad signaling pathways involves in the occurrence of DR,which may be important pathological mechanism in PDR.