The Effects Of Gax Gene MRNA Overexpression On The Phenotype Of Vascular Smooth Muscle Cells In Venous Autografts

ObjectiveAs the wide use of vein grofts in treating coronary artery disease and peripheral artery chemic disease, the stenosis of transplanrted vein caused by inti-mal hyperplasia has become the main factor affecting the long term patency. But in the early period after the operation ( 30days postoperation ) , the blocking ratio of the veins is 5 -26% ; and in the late stage ( 2years postoperation ) , the blocking ratio will up to 40%. That restenosis is mainly caused by intimal hyperplasia and sclerosis. So restenosis reduse the therapeutic effectiveness seriously. The mechamism of IF is not very clear yet. But it is associated with injury , ischemia , PDGF , hemodynamic of transplanted vien has become an important topic of vascular surfery.To explore the effects of Gax gene mRNA overexpression on the phenotype of vascular smooth muscle cells ( VSMCs) in venous autografts, and search for an ideal approach for inhibition of intimal hyperplasia (IH) after autogenous vein grafting.Methods28 Wistar rats weighing 200 - 300 g were randomly divided into 2 groups, a control group and a experimental group, 14 rats in each group. A rat experimental model of autogenouse vein graft was established by transplanting the right internal jugular vein into the common carotide artery in 24 rats. The transplanted vein in the experimental group was coated using glue gel (Pluronic, F127 ) in which recombinant adeno - associatedvirus(rAAV)Gax added just after anastomosis, nothing to be coated except for glue gel in the control group. The vein grafts were taken at 14 days after operation. RT - PCR ( Reverse transcription polymerase chain reaction ) , Immunohistochemical technique, Western blottingand electron microscope were used to detect the expression of gax mRNA, protein , PCNA ( proliferation cell nuclear antigen) and conversion phenotype of VSMCs.ResultsIn the experimental group , there was remarkable increase of expression of gax , PCNA, compared with the contral group (p <0. 05). reduction on the proliferation phenotype of VSMCs.ConclusionThe present study demonstrated that overexpression of gax mRNA can block conversion of VSMCs from constriction phenotype to proliferation phenotype in autogenous vein after vein grafting.