title: Aberrant association between vascular endothelial growth factor receptor-2 and VE-cadherin in response to vascular endothelial growth factor-a in Shb-deficient lung endothelial cells.
abstract: Vascular permeability is a hallmark response to the main angiogenic factor VEGF-A and we have previously described a reduction of this response in Shb knockout mice. To characterize the molecular mechanisms responsible for this effect, endothelial cells were isolated from lungs and analyzed in vitro. Shb deficient endothelial cells exhibited less migration in a scratch wound-healing assay both under basal conditions and after vascular endothelial growth factor-A (VEGF-A) stimulation, suggesting a functional impairment of these cells in vitro. Staining for VE-cadherin and vascular endothelial growth factor receptor-2 (VEGFR-2) showed co-localization in adherens junctions and in intracellular sites such as the perinuclear region in wild-type and Shb knockout cells. VEGF-A decreased the VE-cadherin/VEGFR-2 co-localization in membrane structures resembling adherens junctions in wild-type cells whereas no such response was noted in the Shb knockout cells. VE-cadherin/VEGFR-2 co-localization was also recorded using spinning-disk confocal microscopy and VEGF-A caused a reduced association in the wild-type cells whereas the opposite pattern was observed in the Shb knockout cells. The latter expressed slightly more of cell surface VEGFR-2. VEGF-A stimulated extracellular-signal regulated kinase, Akt and Rac1 activities in the wild-type cells whereas no such responses were noted in the knockout cells. We conclude that aberrant signaling characteristics with respect to ERK, Akt and Rac1 are likely explanations for the observed altered pattern of VE-cadherin/VEGFR-2 association. The latter is important for understanding the reduced in vivo vascular permeability response in Shb knockout mice, a phenomenon that has patho-physiological relevance.
authors.affiliation: Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.
authors.forename: Guangxiang
authors.initials: G
authors.lastname: Zang
authors.forename: Gustaf
authors.initials: G
authors.lastname: Christoffersson
authors.forename: Geng
authors.initials: G
authors.lastname: Tian
authors.forename: Mohammad
authors.initials: M
authors.lastname: Harun-Or-Rashid
authors.forename: Evelina
authors.initials: E
authors.lastname: Vågesjö
authors.forename: Mia
authors.initials: M
authors.lastname: Phillipson
authors.forename: Sebastian
authors.initials: S
authors.lastname: Barg
authors.forename: Anders
authors.initials: A
authors.lastname: Tengholm
authors.forename: Michael
authors.initials: M
authors.lastname: Welsh
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D015820:Cadherins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects*; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D008168:Lung / Q000166:cytology / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D011518:Proto-Oncogene Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D015820:Cadherins; D011518:Proto-Oncogene Proteins; D042461:Vascular Endothelial Growth Factor A; D040301:Vascular Endothelial Growth Factor Receptor-2; D000099152:Cadherin 5; C085634:Shb protein, mouse