title: Modification of actin, myosin and tubulin distribution during cytoplasmic granule movements associated with platelet adhesion.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Departamento de Morfología, Escuela Nacional de Ciencias Biológicas, IPN, Distrito Federal, México.
authors.forename: Doris
authors.initials: D
authors.lastname: Cerecedo
authors.forename: Roberto
authors.initials: R
authors.lastname: Stock
authors.forename: Sirenia
authors.initials: S
authors.lastname: González
authors.forename: Elba
authors.initials: E
authors.lastname: Reyes
authors.forename: Ricardo
authors.initials: R
authors.lastname: Mondragón
mesh_terms: D000199:Actins / Q000378:metabolism; D001792:Blood Platelets / Q000166:cytology / Q000648:ultrastructure; D048429:Cell Size; D003594:Cytoplasmic Granules / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D006801:Humans; D008856:Microscopy, Fluorescence; D009038:Motion; D009218:Myosins / Q000378:metabolism; D010973:Platelet Adhesiveness; D011485:Protein Binding; D014404:Tubulin / Q000378:metabolism
chemical_list: D000199:Actins; D003598:Cytoskeletal Proteins; D014404:Tubulin; D009218:Myosins