ObjectiveTo investigate the expression of extracellular signalregulated kinase (ERK) and p38 mitogenactivated protein kinase （p38 MAPK） in autogenous vein grafts during vascular remodeling.MethodsAn autogenous vein graft model was established by transplanting the right jugular vein to infrarenal abdominal aorta in 80 Wistar rats. Vein graft samples were harvested 6 hours, 24 hours, 3 days, 7 days, 2 weeks, 4 weeks, 6 weeks and 8 weeks after surgery. Gene expression of ERK and p38 MAPK was measured by reverse transcriptionPCR. Western blot was used to detect the expression of protein products and phosphorylation protein products of ERK and p38 MAPK. Apoptosis of vascular smooth muscle cells (VSMCs) was determined by TUNEL. Proliferating cell nuclear antigen(PCNA) of VSMCs also was studied.ResultsThe expression of ERK1 mRNA and p38 MAPK mRNA increased considerably after surgery. ERK1 mRNA reached the peak on the 7th day 〔（33.2±14.2）%, P＜0.01〕, but p38 MAPK mRNA reached the peak on the second week after surgery 〔(58.8±26.2）%, P＜0.01〕. The expression of ERK1/2 detected by western blot reached the peak during 1 to 2 weeks and decreased gradually to normal level 6 weeks after surgery. The expression of p38 MAPK reached the peak during 2 to 4 weeks and decreased to 1/4 to 1/2fold 8 weeks after surgery. There was a positive relationship between ERK1 and PCNA(r=0.759 6，P＜0.01) and a positive relationship between p38 MAPK and apoptosis(r=0.892 2，P＜0.01). ConclusionActivation of MAPK system exists in autogenous vein grafts and it may become a new target for the therapy of stenosis after vein grafts.
ObjectiveTo detect the inhibitory effect of early growth response gene-1 DNA enzyme (EDRz) on proliferation of vascular smooth muscle cell (VSMC) and intimal hyperplasia, and confirm the effect of gene therapy on stenosis and occlusion after vein transplantation. MethodsEDRz was constructed, and autogenous vein graft model was established with Wistar rats, transplanting the right jugular vein to infra renal abdominal aorta by microsurgical technique. EDRz was transfected to the graft veins and the vein graft samples were harvested at hour 1, 2, 6, 24 and on day 3, 7, 14, 28, 42 after grafting, 10 Wistar rats were randomly selected in every time. The expression of EDRz in transfected vein graft was detected by fluorescent microscope. Egr-1 mRNA was measured by reverse transcription-PCR (RT-PCR) and in situ hybridization, respectively. The protein expression of Egr-1 was detected by Western blot and immunohistochemistry, respectively. HE stained vein grafts were observed under microscope. Results① The results of EDRz transfected vein graft: At hour 1 after grafting, EDRz was mainly located in adventitia, tunica media, and partial endothelial cells of vein graft; At hour 2, 6, and 24, EDRz was located in tunica media of vein graft; and on day 7, it was mainly located in intima of vein graft. There wasn’t EDRz in vein grafts on day 14, 28, and 42. ② The results of expression of Egr-1 mRNA: Detection by RT-PCR: At hour 1 after transfecting, the expression of Egr-1 mRNA arrived at the peak, and declined at hour 2, 6, and 24. The expression was tenuity on day 3. Egr-1 mRNA expression was not found on day 7, 14, 28, and 42. The expression of Egr-1 mRNA at hour 1 was significantly higher than that of the other time point (Plt;0.01). The result of in situ hybridization was coincident with RT-PCR. ③ The results of expression of Egr-1 protein: The result of Western blot: There was no expression of Egr-1 protein in normal veins. At hour 2 after grafting, expression of Egr-1 protein was found, and declined at hour 6, 24, and on day 3. There was no expression of Egr-1 protein at hour 1, and on day 7, 14, 28, and 42. The expression of Egr-1 protein at hour 2 was significantly higher than that of the other time point (Plt;0.01). The result of immunohistochemistry was coincident with Western blot. ④The degree of VSMC hyperplasia and intimal thickness were lighter in EDRz transfected vein grafts than that in nottransfected vein grafts contemporarily. ConclusionsEDRz could reduce the expression of Egr-1 in autogenous vein graft, and could effectively restrain VSMC proliferation and intimal hyperplasia, and prevent vascular stenosis and occlusion after vein grafting.