Kodama Michiteru, Naito Michitaka, Nomura Hideki, Iguchi Akihisa, Thompson W Douglas, Stirk Christina M, Smith Elspeth B
Department of Geriatrics, Nagoya University Graduate School of Medicine, 65 Tsuruma-cho, Showa-ku, Nagoya 466-8550, Japan.
Life Sci. 2002 Jul 26;71(10):1139-48. doi: 10.1016/s0024-3205(02)01825-8.
The structure of fibrin plays an important role in the organization of thrombi, the development of atherosclerosis, and restenosis after PTCA. In this study, we examined the mechanisms of the migration of vascular smooth muscle cells (SMCs) into fibrin gels, using an in vitro assay system. Cultured SMCs from bovine fetal aortic media migrated into fibrin gels prepared with thrombin, which cleaves both fibrinopeptides A and B from fibrinogen, without other chemotactic stimuli. Both desA fibrin gels prepared with batroxobin, which cleaves only fibrinopeptide A, and desB fibrin gels prepared with Agkistrodon contortrix thrombin-like enzyme (ACTE), which cleaves only fibrinopeptide B, similarly induced the migration of SMCs compared to fibrin gels prepared with thrombin. These results suggest that the cleavage of fibrinopeptides is not necessary, but rather that the three-dimensional structure of the gel may be important for the migration of SMCs. Furthermore, gels prepared with protamine sulfate, which forms fibrin-like gels non-enzymatically, similarly induced the migration of SMCs compared to the gels prepared with thrombin. Both anti-fibrin(ogen) fragment D and anti-fibrin(ogen) E antibodies inhibited the migration of SMCs into fibrin gels, suggesting that both the D and E domains of fibrin(ogen) are involved in the migration of SMCs into fibrin gels. The addition of GRGDS, a synthetic RGD-containing peptide, but not that of GRGES, a control peptide, partially inhibited the migration of SMCs into fibrin gels, suggesting that the migration of SMCs into fibrin gels is at least in part dependent on the RGD-containing region of the alpha chain. The migration of SMCs into fibrin gels was also inhibited by a monoclonal antibody for integrin alpha v beta 3 and alpha 5 beta 1, indicating that migration is dependent on these integrins. Furthermore, both fibrin(ogen) fragments D and E inhibited the migration of SMCs into fibrin gels, suggesting that these fragments, generated during fibrino(geno)lysis, may be relevant in the regulation of SMC migration into fibrin gels.
纤维蛋白的结构在血栓形成、动脉粥样硬化发展以及经皮腔内冠状动脉成形术（PTCA）后的再狭窄过程中发挥着重要作用。在本研究中，我们使用体外检测系统研究了血管平滑肌细胞（SMC）迁移至纤维蛋白凝胶中的机制。来自牛胎儿主动脉中膜的培养SMC在没有其他趋化刺激的情况下，迁移至用凝血酶制备的纤维蛋白凝胶中，凝血酶可从纤维蛋白原上裂解下纤维蛋白肽A和B。用仅裂解纤维蛋白肽A的巴曲酶制备的desA纤维蛋白凝胶，以及用仅裂解纤维蛋白肽B的蝰蛇毒凝血酶样酶（ACTE）制备的desB纤维蛋白凝胶，与用凝血酶制备的纤维蛋白凝胶相比，同样能诱导SMC迁移。这些结果表明，纤维蛋白肽的裂解并非必需，而是凝胶的三维结构可能对SMC的迁移很重要。此外，用硫酸鱼精蛋白非酶促形成类似纤维蛋白凝胶制备的凝胶，与用凝血酶制备的凝胶相比，同样能诱导SMC迁移。抗纤维蛋白（原）片段D和抗纤维蛋白（原）E抗体均抑制了SMC向纤维蛋白凝胶中的迁移，表明纤维蛋白（原）的D和E结构域均参与了SMC向纤维蛋白凝胶中的迁移。添加合成的含RGD肽GRGDS，但不添加对照肽GRGES，部分抑制了SMC向纤维蛋白凝胶中的迁移，表明SMC向纤维蛋白凝胶中的迁移至少部分依赖于α链的含RGD区域。针对整合素αvβ3和α5β1的单克隆抗体也抑制了SMC向纤维蛋白凝胶中的迁移，表明迁移依赖于这些整合素。此外，纤维蛋白（原）片段D和E均抑制了SMC向纤维蛋白凝胶中的迁移，表明这些在纤维蛋白（原）溶解过程中产生的片段可能与调节SMC向纤维蛋白凝胶中的迁移有关。
