[摘要]：alpha B-crystallin, a low-molecular-weight heat shock protein (HSP), has binding sites on platelets. However, the exact role of alpha B-crystallin is not clarified. In this study, we investigated the effect of alpha B-crystallin on platelet granule secretion. alpha B-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 alpha B-crystallin. alpha B-crystallin significantly suppressed the ADP- induced secretions of both platelet-derived growth factor (PDGF)-AB and serotonin. Therefore, our results strongly suggest that alpha B-crystallin extracellularly suppresses platelet granule secretion by inhibition of HSP27 phosphorylation via p44/p42 MAPK and p38 MAPK. (c) 2009 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.
