Mice Lacking the Inhibitory Collagen Receptor LAIR-1 Exhibit a Mild Thrombocytosis and Hyperactive Platelets.
Arterioscler Thromb Vasc Biol
; 37(5): 823-835, 2017 05.
Article
en En
| MEDLINE
| ID: mdl-28336561
ABSTRACT
OBJECTIVE:
Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is a collagen receptor that belongs to the inhibitory immunoreceptor tyrosine-based inhibition motif-containing receptor family. It is an inhibitor of signaling via the immunoreceptor tyrosine-based activation motif-containing collagen receptor complex, glycoprotein VI-FcRγ-chain. It is expressed on hematopoietic cells, including immature megakaryocytes, but is not detectable on platelets. Although the inhibitory function of LAIR-1 has been described in leukocytes, its physiological role in megakaryocytes and in particular in platelet formation has not been explored. In this study, we investigate the role of LAIR-1 in megakaryocyte development and platelet production by generating LAIR-1-deficient mice. APPROACH ANDRESULTS:
Mice lacking LAIR-1 exhibit a significant increase in platelet counts, a prolonged platelet half-life in vivo, and increased proplatelet formation in vitro. Interestingly, platelets from LAIR-1-deficient mice exhibit an enhanced reactivity to collagen and the glycoprotein VI-specific agonist collagen-related peptide despite not expressing LAIR-1, and mice showed enhanced thrombus formation in the carotid artery after ferric chloride injury. Targeted deletion of LAIR-1 in mice results in an increase in signaling downstream of the glycoprotein VI-FcRγ-chain and integrin αIIbß3 in megakaryocytes because of enhanced Src family kinase activity.CONCLUSIONS:
Findings from this study demonstrate that ablation of LAIR-1 in megakaryocytes leads to increased Src family kinase activity and downstream signaling in response to collagen that is transmitted to platelets, rendering them hyper-reactive specifically to agonists that signal through Syk tyrosine kinases, but not to G-protein-coupled receptors.Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Trombocitosis
/
Trombosis
/
Plaquetas
/
Megacariocitos
/
Receptores Inmunológicos
/
Activación Plaquetaria
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Arterioscler Thromb Vasc Biol
Asunto de la revista:
ANGIOLOGIA
Año:
2017
Tipo del documento:
Article