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Hypoxia/Reoxygenation Induced Blood Cell Adhesion in Cerebral Venules of Sickle Cell Transgenic (β S ) Mice: The Two Faces of eNOS
Author(s) -
Wood Katherine C,
Hebbel Robert P,
Lefer David J,
Granger D. Neil
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.lb22-b
Subject(s) - enos , hypoxia (environmental) , chemistry , nadph oxidase , endothelium , endothelial stem cell , nitric oxide , immunology , biology , nitric oxide synthase , oxidative stress , endocrinology , biochemistry , oxygen , organic chemistry , in vitro
Oxidative stress has been implicated in blood cell‐vessel wall interactions of β S mice. Intravital fluorescence microscopy and bone marrow (BM) transplantation were used to examine the influence of different superoxide‐ and nitric oxide‐directed interventions on leukocyte and platelet adhesion in cerebral venules of β S mice. Two h hypoxia and 4 h reoxygenation elicited intense leukocyte and platelet adhesion responses in β S mice that were attenuated by genetic deficiency of vascular gp91phox or overexpression of vascular CuZnSOD; allopurinol treatment was without effect. Treatment with L‐NAME or genetic deficiency of vascular eNOS also decreased cell adhesion responses whereas treatment with DETA‐NO or genetic overexpression of vascular eNOS exacerbated the cell adhesion responses; genetic deficiency of vascular iNOS was without effect. Sepiapterin, similar to PEG‐SOD, effectively reduced the enhanced cell adhesion responses in β S mice. In conclusion, vascular NADPH oxidase and eNOS are major contributors to the pro‐inflammatory and pro‐thrombogenic phenotype assumed by the cerebral microvasculature of β S mice. These findings suggest that the inflammatory environment created by β S BM leads to NADPH oxidase activation in endothelial cells as well as the functional inactivation of vascular eNOS enzyme, and possibly includes roles for peroxynitrite formation and/or eNOS uncoupling. (HL26441, P01‐HL55552)