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A heat shock‐related protein, p20, plays an inhibitory role in platelet activation
Author(s) -
Matsuno Hiroyuki,
Kozawa Osamu,
Niwa Masayuki,
Usui Akihiko,
Ito Hidenori,
Uematsu Toshihiko,
Kato Kanefusa
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00626-7
Subject(s) - platelet , ex vivo , chemistry , heat shock protein , thrombin , platelet activation , molecular mass , in vivo , in vitro , biochemistry , hsp27 , thrombus , hsp70 , biophysics , microbiology and biotechnology , pharmacology , biology , immunology , medicine , enzyme , gene
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 previously that a 20‐kDa protein (p20), which is classified as a low molecular mass HSP, is present at high levels in skeletal and smooth muscles. In the present study, we investigated a physiological role of p20 on platelet function in vitro and ex vivo. p20 inhibited platelet aggregation using human platelets dose‐dependently induced by botrocetin. On the other hand, HSP27, the other type of low molecular mass HSP, did not affect platelet aggregation. When p20 (300 μg/kg) was injected intravenously as a bolus in hamsters, platelet aggregation ex vivo induced by botrocetin was also significantly inhibited. In order to further investigate the inhibitory effect by p20 on platelet activation, we performed platelet aggregation induced by thrombin or ADP using human platelets. p20 markedly prevented platelet aggregation induced by thrombin, but not ADP. These findings suggest that p20 can act intercellularly to regulate platelet functions. Our results may provide the basis for a novel defensive system to thrombus formation.