Hu Xin-hua, Zhang Qiang, Yang Jun, Liu Cheng-wei, Zhang Zhi-shen, Wang Jun, Liu Ge-fei
Department of Vascular Surgery, First Affiliated Hospital, China Medical University, Shenyang 110001, China.
Zhonghua Wai Ke Za Zhi. 2006 Aug 1;44(15):1053-7.
To investigate the expression of mammalian target of rapamycin (mTOR) and its substrates including p70s6k and 4E-BP1 in autogenous vein graft.
Autogenous vein graft model was established in 64 Wistar rats by transplanting the right common jugular vein to infrarenal abdominal aorta. Vein graft samples were harvested 6 hours, 1 day, 3 days, 1 week, 2 weeks, 4 weeks, 6 weeks and 8 weeks after surgery. The mRNA expression of mTOR, p70s6k and 4E-BP1 were measured by RT-PCR and in situ hybridization. Western blot and immunohistochemistry methods also were used to detect the protein expression of mTOR, p70s6k and 4E-BP1. Proliferating cell nuclear antigen (PCNA) was also detected at the same time.
The mRNA expression of mTOR and p70s6k increased soon after vein graft transplanting, rose quickly and reached the peak 3 days to 2 weeks after surgery, which recovered 6 to 8 weeks after surgery. The expression of 4E-BP1 mRNA decreased soon after surgery and reached the lowest at 1 week, then rose to the peak 4 to 6 weeks after transplantation. Protein expression of mTOR and p70s6k reached the peak 2 to 4 weeks and recovered to normal level 8 weeks after surgery, but the expression of 4E-BP1 decreased to the lowest during 1 to 2 weeks and reached the peak 4 to 6 weeks after transplanting. The positive cells mostly located in vascular smooth muscle cell (VSMC) just like PCNA.
The expression of mTOR and its substrates were activated in vein graft soon after transplantation, which means that mTOR and its substrates might become new targets for the prevention and therapy of stenosis or obliteration after vein graft transplanting.
研究雷帕霉素靶蛋白（mTOR）及其底物包括p70s6k和4E-BP1在自体静脉移植物中的表达。
将64只Wistar大鼠的右颈总静脉移植至肾下腹主动脉，建立自体静脉移植物模型。于术后6小时、1天、3天、1周、2周、4周、6周和8周采集静脉移植物样本。采用逆转录聚合酶链反应（RT-PCR）和原位杂交法检测mTOR、p70s6k和4E-BP1的mRNA表达。同时采用蛋白质印迹法和免疫组织化学方法检测mTOR、p70s6k和4E-BP1的蛋白表达。并检测增殖细胞核抗原（PCNA）。
静脉移植物移植后，mTOR和p70s6k的mRNA表达迅速增加，术后3天至2周迅速上升并达到峰值，术后6至8周恢复。4E-BP1 mRNA表达术后迅速下降，1周时降至最低，然后在移植后4至6周升至峰值。mTOR和p70s6k的蛋白表达在术后2至4周达到峰值，术后8周恢复至正常水平，但4E-BP1的表达在1至2周降至最低，移植后4至6周达到峰值。阳性细胞大多位于血管平滑肌细胞（VSMC），与PCNA情况相同。
移植后静脉移植物中mTOR及其底物的表达迅速被激活，这意味着mTOR及其底物可能成为预防和治疗静脉移植物移植后狭窄或闭塞的新靶点。
