Shencheng Ge, James G White, Christy L Haynes
Department of Chemistry, College of Science and Engineering, University of Minnesota , Minneapolis, MN 55455 , USA.
Platelets 2012Cytoskeletal F-actin assembly and microtubule reorganization are principal cellular events responsible for activation-induced platelet shape change; however, their roles in regulating platelet secretion have remained controversial. Herein, label-free microelectrochemistry techniques and pharmacological approaches are used to probe the role of F-actin and the microtubule in platelet dense-body secretion. Altered microtubule integrity via exposure to paclitaxel or vincristine had no effect on serotonin release in platelet suspensions. Disruption of F-actin by cytochalasin D (CytoD) or latrunculin A (LatA) substantially enhanced the rate of serotonin release, while inhibition of the F-actin-dependent platelet motor protein myosin IIA by blebbistatin had no effect. CytoD-treated platelets also showed enhanced serotonin quantal secretion rate. These results clearly indicate that F-actin, but not the microtubule, regulates platelet dense-body secretion and does so by serving as a physical barrier. This study also demonstrates the promise of microelectrochemistry for giving important insight into platelet quantal secretion mechanisms in future studies.
Shencheng Ge, James G White, Christy L Haynes. Cytoskeletal F-actin, not the circumferential coil of microtubules, regulates platelet dense-body granule secretion. Platelets. 2012;23(4):259-63
PMID: 21988315
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