Immunocytochemical Study on the Redistribution of alphallbbeta3 Integrin and Cytoskeleton adherent to collagen

血小板与胶原蛋白的初始接触是通过α 2 β 1整合素介导的。α 2 β 3整合素参与血小板扩散。然而，导致血小板在胶原蛋白上扩散和牢固粘附的确切机制尚不清楚。我们用免疫扫描电子显微镜观察到粘附在胶原上的血小板分泌纤维蛋白原，纤维蛋白原在血小板铺展过程中作为血小板β 3的锚定/配体，我们用免疫荧光显微镜观察了粘附在胶原上的人血小板的细胞骨架模式。肌动蛋白被检测为对齐的补丁，并位于沿着肌动蛋白丝。虽然在肌动蛋白丝的末端没有检测到塔林，但它集中在血小板与相邻血小板紧密接触的血小板周围。检测到PP 125 μ g<FAK>为小斑点，所有这些斑点作为一个整体在粘附血小板的中心区域形成一个环。这些结果表明，粘附的血小板不能形成典型的局灶性粘附。

Initial contact of platelets with collagen is mediated via alpha2beta1 integrin.alphallbbeta3 is involved in platelet spreading. However, the precise mechanism leading to platelet spreading and firm adhesion on collagen are less understood. We have found by immuno-scanning electron microscopy that the platelets adherent to immobilized collagen secreted fibrinogen which then settled onto the cover soip and worked as an anchorage/ligand for alphallbbeta3 during platelet spreading.Next, we have examined the cytoskeletal patterns in human platelets adherent to collagen using immunofluorescence microscopy. Vinculin was detected as aligned patches, and located along actin filaments. Although talin was not detected at the ends of actin filaments, it was concentrated at the periphey of the platelets where the platelets were in close contact with adjacent platelets. pp125^<FAK> was detected as small spots, all of which, as a whole, formed a ring at the central areas of adherent platelets. These results suggest that the adherent platelets fail to form typical focal adhesion.