Cerecedo Doris, Stock Roberto, González Sirenia, Reyes Elba, Mondragón Ricardo
Departamento de Morfología, Escuela Nacional de Ciencias Biológicas, IPN, Distrito Federal, México.
Haematologica. 2002 Nov;87(11):1165-76.
Cytoskeletal elements determine the changes in platelet cell shape which occur during adhesion, aggregation and release of granular contents as part of the activation process. The aim of this study was to characterize the changes in the distribution of actin filaments, myosin and tubulin molecules during several stages of platelet adhesion to glass and their association with granule displacement, as assessed by confocal microscopy.
Platelets obtained from healthy donors were adhered to glass and cytoskeleton distribution was characterized and correlated to changes of cell shape and intracellular granule displacement by immunofluorescence assays and phase contrast microscopy. Treatment with specific cytoskeleton inhibitors such as cytochalasin D, butanedione monoxime and colchicine were used before and after the adhesion process. The spatial distribution of the cytoskeleton in association with cytoplasmic granules was analyzed in both confocal microscopy projections and three-dimensional images obtained by merging the respective projections.
Our experiments revealed that as platelets contact the substrate, a sequential and simultaneous rearrangement of actin filaments, myosin and tubulin molecules occurred and this was related to cell shape, as well as to movements of cytoplasmic granules. Treatment of platelets with cytoskeleton inhibitors, modified not only the target molecule but also other cytoskeletal components with consequent alterations in the studied platelet functions.
During platelet adhesion to glass and granule displacement, a close spatial and functional relation between actin filaments, myosin molecules and microtubules was observed suggesting that these different cytoskeleton components interact in supporting the platelet functions here studied.
细胞骨架成分决定了血小板在粘附、聚集以及颗粒内容物释放（作为激活过程的一部分）期间发生的细胞形状变化。本研究的目的是通过共聚焦显微镜评估，表征血小板粘附于玻璃的几个阶段中肌动蛋白丝、肌球蛋白和微管蛋白分子分布的变化及其与颗粒位移的关联。
从健康供体获取的血小板粘附于玻璃，通过免疫荧光测定和相差显微镜表征细胞骨架分布，并将其与细胞形状变化和细胞内颗粒位移相关联。在粘附过程之前和之后使用细胞松弛素D、丁二酮一肟和秋水仙碱等特定细胞骨架抑制剂进行处理。在共聚焦显微镜投影以及通过合并各自投影获得的三维图像中分析细胞骨架与细胞质颗粒相关的空间分布。
我们的实验表明，随着血小板与底物接触，肌动蛋白丝、肌球蛋白和微管蛋白分子发生了顺序且同时的重排，这与细胞形状以及细胞质颗粒的移动有关。用细胞骨架抑制剂处理血小板，不仅改变了靶分子，还改变了其他细胞骨架成分，从而改变了所研究的血小板功能。
在血小板粘附于玻璃和颗粒位移过程中，观察到肌动蛋白丝、肌球蛋白分子和微管之间存在密切的空间和功能关系，表明这些不同的细胞骨架成分在支持此处所研究的血小板功能方面相互作用。
