Dollery C M, McEwan J R, Wang M, Sang Q A, Liu Y E, Shi Y E
Hatter Institute, University College London Hospitals, London, UK.
Circ Res. 1999 Mar 19;84(5):498-504. doi: 10.1161/01.res.84.5.498.
The role of basement membrane-degrading matrix metalloproteinases (MMPs) in enabling vascular smooth muscle cell migration after vascular injury has been established in several animal models. In contrast, the role of their native inhibitors, the tissue inhibitors of matrix metalloproteinases (TIMPs), has remained unproven despite frequent coregulation of MMPs and TIMPs in other disease states. We have investigated the time course of expression and localization of TIMP-4 in rat carotid arteries 6 hours, 24 hours, 3 days, 7 days, and 14 days after balloon injury by in situ hybridization, immunohistochemistry, and Western blot analysis. TIMP-4 protein was present in the adventitia of injured carotid arteries from 24 hours after injury. At 7 and 14 days after injury, widespread immunostaining for TIMP-4 was observed throughout the neointima, media, and adventitia of injured arteries. Western blot analysis confirmed the quantitative increase in TIMP-4 protein at 7 and 14 days. In situ hybridization detected increased expression of TIMP-4 as early as 24 hours after injury and a marked induction in neointimal cells 7 days after injury. We then studied the effect of TIMP-4 protein on the migration of smooth muscle cells through a matrix-coated membrane in vitro and demonstrated a 53% reduction in invasion of rat vascular smooth muscle cells. These data and the temporal relationship between the upregulation of TIMP-4, its accumulation, and the onset of collagen deposition suggest an important role for TIMP-4 in the proteolytic balance of the vasculature controlling both smooth muscle migration and collagen accumulation in the injured arterial wall.
在多种动物模型中已证实，基底膜降解基质金属蛋白酶（MMPs）在血管损伤后促使血管平滑肌细胞迁移方面发挥作用。相比之下，尽管在其他疾病状态下MMPs和基质金属蛋白酶组织抑制剂（TIMPs）常共同调节，但TIMPs作为其天然抑制剂的作用仍未得到证实。我们通过原位杂交、免疫组织化学和蛋白质印迹分析，研究了大鼠颈动脉球囊损伤后6小时、24小时、3天、7天和14天TIMP-4的表达时间进程和定位。损伤后24小时，TIMP-4蛋白出现在损伤颈动脉的外膜。损伤后7天和14天，在损伤动脉的整个新生内膜、中膜和外膜均观察到广泛的TIMP-4免疫染色。蛋白质印迹分析证实，损伤后7天和14天TIMP-4蛋白定量增加。原位杂交检测到损伤后24小时TIMP-4表达即增加，损伤后7天新生内膜细胞中TIMP-4显著诱导表达。然后我们研究了TIMP-4蛋白对体外平滑肌细胞通过基质包被膜迁移的影响，结果显示大鼠血管平滑肌细胞侵袭减少了53%。这些数据以及TIMP-4上调、其积累与胶原沉积开始之间的时间关系表明，TIMP-4在控制受损动脉壁平滑肌迁移和胶原积累的血管蛋白水解平衡中起重要作用。
