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

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-β_1) 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-β_1 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-β_1. Results Expression of Egr-1,PDGF-B,TGF-β_1 mRNA and protein was not detected in normal vein.In grafting vein,expression level of Egr1mRNA reached a peak at 28days,and the positive rate of Egr-1mRNA was 45%±6%;(PDGF-BmRNA) reached a peak at 14days(48%±6%);a peak of TGF-β_1mRNA was 46%±9% reached at 7days;Egr-1 protein expression reached a peak at 28days, and the positive rate of Egr-1 protein was 40%±9%.PDGF-B protein reached a peak at 28days(45%±4%),TGF-β_1 protein reached a peak at 14days(41%±7%).Conclusions Intimal hyperplasia of vein graft is closely associated withexpression of Egr-1、PDGF-B and TGF-β_1;the activation and expression of PDGF-B and TGF-β_1 may be(modulated) by Egr-1,and they may contribute to increase expression of Egr-1 by feedback.