兔颅内动脉瘤Toll样受体4及血管细胞间黏附分子-1的表达

Expression of Toll-like receptor 4 and vascular cell adhesion molecule-1 in intracranial aneurysms of rabbits

目的 观察兔颅内血流相关性动脉瘤形成过程中Toll样受体4（TLR4）及血管细胞间黏附分子-1（VCAM-1）的表达及影响.方法 新西兰大白兔40只,分为正常组5只、假手术组5只、手术组每组各10只（术后1、4、8周）.采用双侧颈总动脉结扎法造模,假手术组仅暴露双侧颈总动脉.所有动物行颅内多普勒（TCD）及磁共振成像（MRI）检查作流体力学分析,处死行病理染色观察血管形态、血管内膜及中弹力层变化,免疫组织化学染色及Western blot观察每组TLR4、VCAM-1表达阳性率及表达量.结果 TLR4在基底动脉尖部免疫组织化学染色阳性表达率分别为：对照组： （11.091±1.216）%;术后1周组：（21.109±3.227）%（t=-6.496,P=0.001）;术后4周组：（22.838±2.130）%（t=-10.709,P=0.000）;术后8周组：（27.480±1.981）%（t=-15.762,P=0.000）;VCAM-1的阳性表达率分别为：对照组：（15.702±0.795）%;术后1周组： （24.414±1.523）%（t=-11.341,P=0.000）;术后4周组：（28.588±1.517）%（t=-16.830,P=0.000）;术后8周组：（34.196±4.196）%（t=-9.681,P=0.000）.手术组与对照组比较差异有统计学意义.Western blot结果显示TLR4相对表达量分别为：对照组： 0.156±0.001;术后1周组： 1.116±0.061（t=-102.613,P=0.000）;术后4周组： 1.376±0.083（t=-19.929,P=0.003）;术后8周组： 2.178±0.151（t=-23.215,P=0.002）;各实验组与对照组比较差异有统计学意义;VCAM-1相对表达量分别为：对照组：2.178±0.151;术后1周组：0.525±0.027（t=-25.525,P=0.001）;术后4周组：0.745±0.021（t=-49.109,P=0.000）;术后8周组：0.666±0.030（t=-30.866,P=0.000）;各实验组与对照组比较差异有统计学意义.结论 TLR4及VCAM-1在兔血流相关性动脉瘤中参与了动脉瘤形成的过程.

Objective To investigate the expression of Toll-like receptor 4 （TLR4） and vascular cell adhesion protein-1 （VCAM-1） during aneurysm formation in rabbits.Methods Forty rabbits were randomly divided into three groups： normal groups （n=5）, sham groups （n=5）, bilateral carotid artery ligation groups （n=30, 1, 4, 8 weeks subgroups, each subgroup 10 rabbits）.Sham group only exposed carotid artery but not ligated, operation group underwent bilateral carotid artery ligation.Blood flow velocity was measured in each group by transcranial Doppler.Magnetic resonance imaging （MRI） tests were used to rebuilt basilar artery models.All rabbits were sacrificed at each time point and went on pathological examination, including hematoxylin and eosin （HE）, elastin-Van Gieson＇s （EVG）, immunohistochemical staining and Western blotting.Results Immunohistochemical staining indicated that the positive rate of TLR4 was as followed： control group： （11.091±1.216）%;1 week group： （21.109±3.227）% （t=-6.496, P=0.001）;4 week group： （22.838±2.130）% （t=-10.709, P=0.000）;8 week group： （27.480±1.981）% （t=-15.762, P=0.000）.The positive rate of VCAM-1 was as followed： control group： （15.702±0.795）%;1 week group： （24.414±1.523）% （t=-11.341, P=0.000）;4 week group： （28.588±1.517）% （t=-16.830, P=0.000）;8 week group： （34.196±4.196）% （t=-9.681, P=0.000）.Western blotting indicated that expressions of TLR4 were higher： 1.116±0.061 （t=-102.613, P=0.000）;1.376±0.083 （t=-19.929, P=0.003）;2.178±0.151 （t=-23.215, P=0.002） than that control group： 0.156±0.001.The expressions of VCAM-1 were higher in surgery group： 0.525±0.027 （t=-25.525, P=0.001）;0.745±0.021 （t=-49.109, P=0.000）;0.666±0.030 （t=-30.866, P=0.000） compared with control group： 0.110±0.008.Conclusion TLR4 and VCAM-1 are involved in the process of aneurysm formation in rabbit blood flow-related aneurysms.