title: Role of vasodilator stimulated phosphoprotein in VEGF induced blood-brain barrier permeability in endothelial cell monolayers.
abstract: The blood-brain barrier (BBB) plays an important role in the pathophysiology of central nervous system (CNS) disorders such as stroke and hypoxic-ischemic brain injury. Vascular endothelial growth factor (VEGF) is involved in angiogenesis and vasogenic edema during stroke and hypoxia. However, the role of VEGF in BBB permeability after hypoxia has not been fully elucidated. We therefore investigated VEGF effects in an in vitro BBB model using rbcec4 endothelial cell line with the stimulation of VEGF or hypoxia. In this study, BBB permeability was studied using (14)C-sucrose detection. The expression of BBB tight junction protein ZO-1, and the expression and phosphorylation of vasodilator stimulated phosphoprotein (VASP), VEGF and VEGF receptor 2 (VEGFR2) were determined using fluorescent immunocytochemistry and western blot analyses. We found that hypoxia upregulated VEGF expression, and VEGF increased BBB permeability. Hypoxia also increased VASP phosphorylation, which was mediated, in part, through VEGFR2. We also found that VASP at tight junctions was co-localized with ZO-1 in cell-cell contacts. Our findings show that VASP phosphorylation is affected by hypoxia and VEGFR2 inhibition suggesting a role for VASP in BBB permeability.
authors.affiliation: Department of Neurology, University of California, San Francisco, CA 94143, USA.
authors.forename: Brandon
authors.initials: B
authors.lastname: Davis
authors.forename: Jun
authors.initials: J
authors.lastname: Tang
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Dezhi
authors.initials: D
authors.lastname: Mu
authors.forename: Xiangning
authors.initials: X
authors.lastname: Jiang
authors.forename: Valerie
authors.initials: V
authors.lastname: Biran
authors.forename: Zinaida
authors.initials: Z
authors.lastname: Vexler
authors.forename: Donna M
authors.initials: DM
authors.lastname: Ferriero
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D015687:Cell Hypoxia / Q000502:physiology*; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology*; D008565:Membrane Proteins / Q000378:metabolism*; D008840:Microfilament Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D051381:Rats; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*; D062826:Zonula Occludens-1 Protein; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D015815:Cell Adhesion Molecules; D008565:Membrane Proteins; D008840:Microfilament Proteins; D010750:Phosphoproteins; C569044:Tjp1 protein, rat; D042461:Vascular Endothelial Growth Factor A; D062826:Zonula Occludens-1 Protein; C467498:vascular endothelial growth factor A, rat; D000098662:Vasodilator-Stimulated Phosphoprotein; D040301:Vascular Endothelial Growth Factor Receptor-2