Egr-1,PDGF-B,TGF-β_1在自体移植静脉中的实验研究

Experimental study of Egr-1,PDGF-B and TGF-β_1 genes in autogenous vein graft

目的研究移植静脉中早期生长反应基因(Egr)-1、血小板源性生长因子(PDGF)-B、转化生长因子(TGF)-β1的表达,探讨它们之间的关系及其在内膜增生(IH)中的作用。方法W istar大鼠9 0只,建立自体静脉移植模型。术后随机分为1,2,6,2 4 h,3,7,1 4,2 8,4 2 d组,分别在相应时点取材,并设正常对照组。应用原位杂交和RT-PCR方法检测Egr-1、PDGF-B、TGF-β1的mRNA表达,联合应用W estern蛋白印迹和免疫组织化学方法检测两组静脉中Egr-1,PDGF-B,TGF-β1蛋白表达情况,同时进行组织形态学研究。结果正常静脉中未检测到Egr-1,PDGF-B,TGF-β1mRNA和蛋白的表达。移植静脉组Egr-1mRNA在移植2 8 d达高峰(4 5%±6%);PDGF-B mRNA在1 4 d达高峰(4 8%±6%);TGF-β1mRNA在7 d达高峰(4 6%±9%)。Egr-1蛋白表达在移植2 8 d达高峰(4 0%±9%);PDGF-B蛋白在2 8 d达高峰(4 5%±4%);TGF-β1蛋白在1 4 d达高峰(4 1%±7%)。结论移植静脉内膜增生与Egr-1,PDGF-B,TGF-β1的表达关系密切;PDGF-B和TGF-β1的激活及表达可能受Egr-1的调节,同时也可能通过反馈机制促进Egr-1的高表达。

Objective To investigate the expression and relationship of early growth response gene - 1 （ Egr-1 ） , platelet - derived growth factor- B （ PDGF - B ） and tranforming growth factor （ TGF-β1） in autogenous vein graft in rats, and the role in vein graft intimal hyperplasia （IH）. Methods Autogenous vein graft model was established in 90 wistar rats. The vein graft samples were harvested at 1 , 2 , 6,24 hours, and 3 , 7 , 14 , 28,42 days after surgery. Normal vein was used as control group. Egr-1, PDGF-B, TGF-β1 mRNA was measured by reverse transcription-PCR and in situ hybridization. Western blotting and immunohistochemistry were used to detect the protein expression of Egr-1 ,PDGF-B and TGF-β1,. Results Expression of Egr-1 , PDGF-B, TGF--β1 mRNA and protein was not detected in normal vein. In grafting vein, expression level of Egr-1 mRNA reached a peak at 28days, and the positive rate of Egr-1 mRNA was 45% _＋ 6%; PDGF-BmRNA reached a peak at 14days （ 48%±6% ） ; a peak of TGF-β1 mRNA was 46% ±9% reached at 7 days ; Egr- 1 protein expression reached a peak at 28 days, and the positive rate of Egr- 1 protein was 40% ±9%. PDGF-B protein reached a peak at 28days（45%±4% ）, TGF-β1 protein reached a peak at 14 days （ 4 1% ±7 % ） . Conclusions Intimal hyperplasia of vein graft is closely associated withexpression of Egr-1 , PDGF-B and TGF-β1 ： the activation and expression of PDGF-B and TGF-β1 may be modulated by Egr-1 . and they may contribute to increase expression of Egr-1 by feedback.