title: The possibility of novel antiplatelet peptides: the physiological effects of low molecular weight HSPs on platelets.
abstract: Some low molecular mass heat shock proteins (HSPs) appear to act as molecular chaperones, but their exact physiological roles have not been fully elucidated. We reported on a physiological role of HSP20, HSP27 and alphaB-crystallin on platelet function in vitro and ex vivo. HSP20 and alphaB-crystallin inhibited platelet aggregation using human platelets dose-dependently induced by thrombin or botrocetin. On the other hand, HSP27, the other type of low molecular mass HSP, did not affect platelet aggregation. When HSP20 or alphaB-crystallin was injected intravenously as a bolus in hamsters, the development of thrombus after endothelial injury was prevented. Moreover, 9 amino-acid sequences isolated from HSP20 or alphaB-crystallin significantly reduced platelet aggregation induced by TRAP, but not a PAR-4 agonist. These findings strongly suggest that HSP20 or alphaB-crystallin can act intercellularly to regulate platelet functions. Our results may provide the basis for a novel defensive system to thrombus formation in vivo.
authors.affiliation: Institute of Biological Science, University of Tsukuba, Iabaraki, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kanno
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Matsuno
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D050888:Heat-Shock Proteins, Small / Q000494:pharmacology / Q000502:physiology*; D006801:Humans; D008954:Models, Biological; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D038203:alpha-Crystallin B Chain / Q000494:pharmacology / Q000502:physiology
chemical_list: D050888:Heat-Shock Proteins, Small; D010455:Peptides; D010975:Platelet Aggregation Inhibitors; D038203:alpha-Crystallin B Chain