Qu Yanming, Shi Xiangen, Zhang Hongwei, Sun Wei, Han Song, Yu Chunjiang, Li Junfa
Department of Neurosurgery, Capital Medical University Affiliated Fu Xing Hospital, Beijing PR China.
J Vasc Surg. 2009 Dec;50(6):1452-8. doi: 10.1016/j.jvs.2009.08.050.
Restenosis is one of several complications following carotid endarterectomy (CEA). The pathogenesis of restenosis may be related to postsurgery inflammation and leukocyte recruitment mediated by cellular adhesion molecules. In this study, we examine the role of vascular cell adhesion molecule-1 (VCAM-1) in carotid neointimal hyperplasia following carotid surgical mechanical de-endothelialization (CSMDE) in a rat model of CEA.
The inhibition of siRNA on VCAM-1 protein expression was determined by using the methods of immunostaining and Western blot. Ultrasound imaging and morphometric analysis were applied to measure the degree of CSMDE-induced carotid artery neointimal hyperplasia of rats.
We found that a lentivirus-based construct expressing a small interfering RNA (siRNA) against VCAM-1 could effectively (P < .05, n = 10 per group) reduce VCAM-1 protein expression in the carotid arteries of rats undergoing CSMDE (CSMDE+RNAi: 135.0 +/- 27.6%) when compared that of CSMDE with scrambled siRNA (CSMDE+CON: 182.7 +/- 36.4%). Doppler ultrasonography revealed that CSMDE+RNAi was accompanied by a significant reduction in the extent of stenosis demonstrated by increased blood velocity (665.85 +/- 48.37 mm/s) and linear diameter (0.59 +/- 0.77 mm) compared to CSMDE+CON (46.72 +/- 28.67 mm/s with undetectable linear diameter, P < .05, n = 10 per group). In addition, morphometric analysis of hematoxylin and eosin (HE)-stained sections indicated that the intima (innermost layer of media at lesion site)/media area ratio (I/M) was significantly increased (P < .05, n = 10 per group) both in the CSMDE (3.99 +/- 0.65) and CSMDE+CON (4.33 +/- 0.59) groups compared with the SHAM group (0.35 +/- 0.13). However, CSMDE+RNAi resulted in a significant (P < .05, n = 10 per group) decrease in the I/M ratio (1.79 +/- 0.43) compared to CSMDE+CON, whereas there were no significant differences in the total arterial area and medial areas among the groups.
These results suggest that perivascular events mediated by VCAM-1 are likely to play an important role in the pathogenesis of carotid artery neointimal hyperplasia in rats after CSMDE.
再狭窄是颈动脉内膜切除术（CEA）后的几种并发症之一。再狭窄的发病机制可能与手术后炎症以及细胞黏附分子介导的白细胞募集有关。在本研究中，我们在CEA大鼠模型中研究了血管细胞黏附分子-1（VCAM-1）在颈动脉手术机械性去内皮化（CSMDE）后颈动脉新生内膜增生中的作用。
采用免疫染色和蛋白质印迹法测定小干扰RNA（siRNA）对VCAM-1蛋白表达的抑制作用。应用超声成像和形态计量分析来测量CSMDE诱导的大鼠颈动脉新生内膜增生程度。
我们发现，表达针对VCAM-1的小干扰RNA（siRNA）的慢病毒构建体能够有效（P <.05，每组n = 10）降低接受CSMDE的大鼠颈动脉中VCAM-1蛋白的表达（CSMDE + RNAi：135.0 +/- 27.6%），与CSMDE加乱序siRNA（CSMDE + CON：182.7 +/- 36.4%）相比。多普勒超声检查显示，与CSMDE + CON相比，CSMDE + RNAi伴随着狭窄程度的显著降低，表现为血流速度增加（665.85 +/- 48.37 mm/s）和线性直径增加（0.59 +/- 0.77 mm）（CSMDE + CON为46.72 +/- 28.67 mm/s，线性直径不可测，P <.05，每组n = 10）。此外，苏木精和伊红（HE）染色切片的形态计量分析表明，与假手术组（0.35 +/- 0.13）相比，CSMDE组（3.99 +/- 0.65）和CSMDE + CON组（4.33 +/- 0.59）的内膜（病变部位中膜最内层）/中膜面积比（I/M）均显著增加（P <.05，每组n = 10）。然而，与CSMDE + CON相比，CSMDE + RNAi导致I/M比显著降低（P <.05，每组n = 10）（1.79 +/- 0.43），而各组之间的总动脉面积和中膜面积没有显著差异。
这些结果表明，VCAM-1介导的血管周围事件可能在CSMDE后大鼠颈动脉新生内膜增生的发病机制中起重要作用。
