Stromal cell-derived factor-1α/C-X-C chemokine receptor type 4 axis promotes endothelial cell barrier integrity via phosphoinositide 3-kinase and Rac1 activation.
Arterioscler Thromb Vasc Biol
; 34(8): 1716-22, 2014 Aug.
Article
em En
| MEDLINE
| ID: mdl-24925969
ABSTRACT
OBJECTIVE:
Although stromal cell-derived factor (SDF)-1αis well known to modulate the mobilization of hematopoietic stem cells and endothelial progenitor cells, its effects on some pre-existing vascular functions remain unknown. We have investigated here the role of SDF-1αsignaling in endothelial barrier function. APPROACH ANDRESULTS:
Treatment with SDF-1α elevated transendothelial electrical resistance and inhibited the dextran hyperpermeability elicited by thrombin in bovine aortic endothelial cells, both indicating an increase in endothelial barrier function. SDF-1α binds to 2 receptors, C-X-C chemokine receptor types 4 and 7 (CXCR4 and CXCR7). Pretreatment with a CXCR4 antagonist or CXCR4 gene depletion by small interfering RNA (siRNA) eliminated SDF-1α-induced endothelial barrier enhancement. In contrast, CXCR7 antagonist or CXCR7 gene depletion by siRNA did not influence SDF-1α-induced barrier enhancement. Pretreatment with a Gi-protein inhibitor, a phosphoinositide 3-kinase (PI3K) inhibitor, or PI3K p110γsubunit gene depletion by siRNA also inhibited SDF-1α-induced barrier enhancement significantly. Western blot analysis revealed that SDF-1α phosphorylated Akt(Ser473) in endothelial cells, suggesting PI3K activation. Immunostaining showed that treatment with SDF-1αformed a cortical actin rim, which was accompanied by Rac1 activation. In vivo, SDF-1αinhibited croton oil-induced vascular leakage indexed by dye extravasation, which is attenuated by a pretreatment with a CXCR4 antagonist.CONCLUSIONS:
We have identified SDF-1α as a novel suppressor of endothelial permeability. Specifically, SDF-1α stimulates the CXCR4/PI3K/Rac1 signaling pathway and the subsequent cytoskeletal rearrangement.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Permeabilidade Capilar
/
Transdução de Sinais
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Receptores CXCR4
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Proteínas rac1 de Ligação ao GTP
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Células Endoteliais
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Quimiocina CXCL12
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Fosfatidilinositol 3-Quinase
Tipo de estudo:
Prognostic_studies
Limite:
Animals
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Humans
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Male
Idioma:
En
Revista:
Arterioscler Thromb Vasc Biol
Assunto da revista:
ANGIOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
Japão