CalDAG-GEFI Deficiency Reduces Atherosclerotic Lesion Development in Mice.
Arterioscler Thromb Vasc Biol
; 36(5): 792-9, 2016 05.
Article
em En
| MEDLINE
| ID: mdl-26988592
ABSTRACT
OBJECTIVE:
Platelets are important for the development and progression of atherosclerotic lesions. However, relatively little is known about the contribution of platelet signaling to this pathological process. Our recent work identified 2 independent, yet synergistic, signaling pathways that lead to the activation of the small GTPase Rap1; one mediated by the guanine nucleotide exchange factor, CalDAG-GEFI (CDGI), the other by P2Y12, a platelet receptor for adenosine diphosphate and the target of antiplatelet drugs. In this study, we evaluated lesion formation in atherosclerosis-prone low-density lipoprotein receptor deficient (Ldlr(-/-)) mice lacking CDGI or P2Y12 in hematopoietic cells. APPROACH ANDRESULTS:
Lethally irradiated Ldlr(-/-) mice were reconstituted with bone marrow from wild-type (WT), Caldaggef1(-/-) (cdgI(-/-)), p2y12(-/-), or cdgI(-/-)p2y12(-/-) (double knockout [DKO]) mice and fed a high-fat diet for 12 weeks. Ldlr(-/-) chimeras deficient for CDGI or P2Y12 developed significantly smaller atherosclerotic lesions in the aortic sinus and in aortas when compared with the Ldlr(-/-)/WT controls. We also observed a significant reduction in platelet-leukocyte aggregates in blood from hypercholesterolemic Ldlr(-/-)/cdgI(-/-) and Ldlr(-/-)/p2y12(-/-) chimeras. Consistently, fewer macrophages and neutrophils were detected in the aortic sinus of Ldlr(-/-)/cdgI(-/-) and Ldlr(-/-)/ p2y12(-/-) chimeras. Compared with controls, the plaque collagen content was significantly higher in Ldlr(-/-) chimeras lacking CDGI. Interestingly, no statistically significant additive effects were seen in Ldlr(-/-)/DKO chimeras when compared with chimeras lacking only CDGI.CONCLUSIONS:
Our findings suggest that CDGI is critical for atherosclerotic plaque development in hypercholesterolemic Ldlr(-/-) mice because of its contribution to platelet-leukocyte aggregate formation and leukocyte recruitment to the lesion area.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aorta
/
Doenças da Aorta
/
Fatores de Troca do Nucleotídeo Guanina
/
Aterosclerose
/
Placa Aterosclerótica
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Arterioscler Thromb Vasc Biol
Assunto da revista:
ANGIOLOGIA
Ano de publicação:
2016
Tipo de documento:
Article