title: alphaB-crystallin extracellularly suppresses ADP-induced granule secretion from human platelets.
abstract: alphaB-crystallin, a low-molecular-weight heat shock protein (HSP), has binding sites on platelets. However, the exact role of alphaB-crystallin is not clarified. In this study, we investigated the effect of alphaB-crystallin on platelet granule secretion. alphaB-crystallin attenuated the adenosine diphosphate (ADP)-induced phosphorylation of p44/p42 mitogen-activated protein kinase (MAPK) and p38 MAPK. The ADP-stimulated HSP27 phosphorylation was markedly reduced by alphaB-crystallin. alphaB-crystallin significantly suppressed the ADP-induced secretions of both platelet-derived growth factor (PDGF)-AB and serotonin. Therefore, our results strongly suggest that alphaB-crystallin extracellularly suppresses platelet granule secretion by inhibition of HSP27 phosphorylation via p44/p42 MAPK and p38 MAPK.
authors: Department of Neurosurgery, Gifu University Graduate School of Medicine, Gifu, Japan.
authors: Yukiko
authors: Y
authors: Enomoto
authors: Seiji
authors: S
authors: Adachi
authors: Rie
authors: R
authors: Matsushima-Nishiwaki
authors: Masayuki
authors: M
authors: Niwa
authors: Haruhiko
authors: H
authors: Tokuda
authors: Shigeru
authors: S
authors: Akamatsu
authors: Tomoaki
authors: T
authors: Doi
authors: Hisaaki
authors: H
authors: Kato
authors: Shinichi
authors: S
authors: Yoshimura
authors: Shinji
authors: S
authors: Ogura
authors: Toru
authors: T
authors: Iwama
authors: Osamu
authors: O
authors: Kozawa
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D022142:Secretory Vesicles / Q000378:metabolism*; D038203:alpha-Crystallin B Chain / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D055551:HSP27 Heat-Shock Proteins; D038203:alpha-Crystallin B Chain; D000244:Adenosine Diphosphate; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases