Monocytic thrombomodulin promotes cell adhesion through interacting with its ligand, Lewisy.
Immunol Cell Biol
; 95(4): 372-379, 2017 04.
Article
em En
| MEDLINE
| ID: mdl-27808085
ABSTRACT
The leukocyte adhesion cascade involves multiple events that efficiently localize circulating leukocytes into the injured sites to mediate inflammatory responses. From rolling to firm adhesion, the interactions between adhesion molecules have pivotal roles in increasing the avidity of leukocytes to endothelial cells. Thrombomodulin (TM), an essential anticoagulant protein in the vasculature, is also expressed on leukocytes. We previously demonstrated that Lewisy (Ley), a specific ligand of TM, is upregulated in inflamed endothelium and is involved in leukocyte adhesion. The current study aimed to investigate whether leukocyte-expressed TM promotes cell adhesion by interacting with Ley. Using human monocytic THP-1 cells as an in vitro cell model, we showed that TM increases THP-1 cell adhesion to inflamed endothelium as well as to Ley-immobilized surface. When THP-1 adhered to activated endothelium and Ley-immobilized surface, the TM distribution became polarized. Addition of soluble Ley to a suspension of THP-1 cells with TM expression triggered an increase in the level of phosphorylated p38 mitogen-activated protein kinase (MAPK), which enabled THP-1 to adhere firmly to intercellular adhesion molecule (ICAM)-1 by activating ß2 integrins. In vivo, macrophage infiltration and neointima formation following arterial ligation-induced vascular injury were higher in wild-type TM (TMflox/flox) than in myeloid-specific TM-deficient (LysMcre/TMflox/flox) mice. Taken together, these results suggest a novel function for TM as an adhesion molecule in monocytes, where it enhances cell adhesion by binding Ley, leading to ß2 integrin activation via p38 MAPK.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Monócitos
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Trombomodulina
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Células Endoteliais
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Neointima
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Inflamação
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Immunol Cell Biol
Assunto da revista:
ALERGIA E IMUNOLOGIA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Taiwan