The Expression And Significance Of TSG-6 In Autografted Vein Wall Of Rats Under Protection Of External Stent

Objective:To observe the expression of TSG-6 in autografted vein wall,explore the effect as well as possible mechanism and understand the influence by external stent,TNF-α as well as IL-1,which provides new approach and theory of vascular restenosis after clinical grafting treatment.Methods:A total of 30 SPF rats were supplied by Anhui animal center weighting between 270 and 330 g and without gender restriction.All rats were divided into three groups,Sham surgery(JA),Stent(ZA)and Non-stent(WA)and 10 were assigned in each group.In JA group,the right external jugular vein of rats was isolated and preserved in situ and subcutaneous tissue as well as skin of incision were sewed.In WA group,modified Cuff was performed.External jugular vein with length of 1.5cm was autografted into ipsilateral carotid artery.In ZA group,external stents were placed into grafted veins based on surgery performed in WA group(the end trasfusion tube of 20 G intravenous indwelling needles)for prevetion of over expansion of grafted veins.Vascualr ultrasound was performed for rats in both ZA and JA at 2 and 8 weeks after surgry to evaluate the flow of veins.Rats were fed under the same condition and Asprin was used at 10mg/kg/d with intragastric administration to prevent thrombosis.All rats in three groups were fed for 12 weeks and then sampling was performed.The samples were divided into two parts.One was placed into-80℃ refrigerator for freeze and the other one was fixed by 10% paraformaldehyde.The hyperplasia of intima,media and adventitia was observed through HE staining and thickness was measured and analyzed by computer image system.Western-blot was used to determine the expression of TSG-6,TNF-α and IL-1 in wall of grafted veins.Results:There were no death found for all rats and the flow of veins was stable and clear at 2 weeks after surgery by vascular ultrasound with rate of 15 cm/s.However,the flow signal of one rat in ZA and one rat in WA was found as worse by ultrasound at 8 weeks after surgery,which indicated vascular occlusion.General flow rate was 93.3%.When sampling,visually,in JA,there was no differences for grafted veins compared with normal jugular vein;in ZA,external stents were surrouded by fibrous tissue and the adventitia protected by stents was more smooth.The wall was thicker compared with JA;The pocket-like expansion of grafted veins and obvious artery pulse in WA were found.Compared with ZA,the hyperplasia of intima,media and adventitia in WA was thicker significantly as 1.5,1.7 and 1.8 times,respectively.It was demonstrated through HE staining that compared with JA,the three layers of wall in WA were clear and hyperplasia was significant,especially for media.The expression of TSG-6 in JA was lower than that in both ZA and WA.Compared with ZA,expression of TSG-6 in JA was lower singnificantly(p<0.05),while,compared with WA,expression of TSG-6 in ZA was lower significantly(p<0.001).The expression of TNF-α and IL-1 was associated with that of TSG-6 positively.Compared with WA,the expression of TNF-α and IL-1 in ZA was lower significantly(p<0.05).Conclusions:1)The rat model of jugular vein grafting is easy to establish and perform;2)The expression of TSG-6,TNF-α and IL-1 can be found in wall of grafted veins;3)TSG-6,TNF-α and IL-1 are involved in inflammation of veins and hyperplasia of intima;4)External stent effectively inhibits hyperplasia of wall,control over expansion of grafted veins and prevent vascular restenosis caused by hyperplasia of wall.