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UVB radiation exposes fibrinogen binding sites on platelets by activating protein kinase C via reactive oxygen species
Author(s) -
Marwijk Kooy M.,
Akkerman J. W. N.,
Asbeck S. van,
Borghuis Lizette,
Prooijen H. C.
Publication year - 1993
Publication title -
british journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.907
H-Index - 186
eISSN - 1365-2141
pISSN - 0007-1048
DOI - 10.1111/j.1365-2141.1993.tb08280.x
Subject(s) - platelet , chemistry , superoxide dismutase , reactive oxygen species , apyrase , phospholipase a2 , biochemistry , catalase , fibrinogen , staurosporine , platelet activation , biophysics , protein kinase a , protein kinase c , kinase , oxidative stress , enzyme , biology , immunology
Previous studies have shown that ultraviolet B (UVB) radiation causes platelet aggregation by exposing fibrinogen binding sites via activation of an intracellular mechanism. In the present study we have further investigated the routes of platelet activation following UVB exposure. Evidence is provided that UVB radiation does not activate the platelets via the classical Phospholipase A 2 and Phospholipase C routes. Despite this observation, UVB‐induced fibrinogen binding was found to be correlated with a 40% increase in phosphorylated 47 kD protein. Both findings could be completely inhibited in the presence of staurosporine, a potent inhibitor of protein kinase C (PK‐C). In efforts to explain the mechanism of PK‐C activation by UV radiation we found that both UV‐induced PK‐C activation and platelet aggregation were significantly reduced in the presence of specific scavengers for reactive oxygen species including superoxide dismutase and catalase. We conclude that exposure of platelets to UVB radiation can activate PK‐C via oxygen radicals, resulting in exposure of fibrinogen binding sites and subsequent platelet aggregation.