Sam68 impedes the recovery of arterial injury by augmenting inflammatory response.
J Mol Cell Cardiol
; 137: 82-92, 2019 12.
Article
en En
| MEDLINE
| ID: mdl-31639388
ABSTRACT
OBJECTIVE:
The role of Src-associated-in-mitosis-68-kDa (Sam68) in cardiovascular biology has not been studied. A recent report suggests that Sam68 promotes TNF-α-induced NF-κB activation in fibroblasts. Here we sought to dissect the molecular mechanism by which Sam68 regulates NF-κB signaling and its functional significance in vascular injury. APPROACH ANDRESULTS:
The endothelial denudation injury was induced in the carotid artery of Sam68-null (Sam68-/-) and WT mice. Sam68-/- mice displayed an accelerated re-endothelialization and attenuated neointima hyperplasia, which was associated with a reduced macrophage infiltration and lowered expression of pro-inflammatory cytokines in the injured vessels. Remarkably, the ameliorated vascular remodeling was recapitulated in WT mice after receiving transplantation of bone marrow (BM) from Sam68-/- mice, suggesting the effect was attributable to BM-derived inflammatory cells. In cultured Raw264.7 macrophages, knockdown of Sam68 resulted in a significant reduction in the TNF-α-induced expression of TNF-α, IL-1ß, and IL-6 and in the level of nuclear phospho-p65, indicating attenuated NF-κB activation; and these results were confirmed in peritoneal and BM-derived macrophages of Sam68-/- vs. WT mice. Furthermore, co-immunoprecipitation and mass-spectrometry identified Filamin A (FLNA) as a novel Sam68-interacting protein upon TNF-α treatment. Loss- and gain-of-function experiments suggest that Sam68 and FLNA are mutually dependent for NF-κB activation and pro-inflammatory cytokine expression, and that the N-terminus of Sam68 is required for TRAF2-FLNA interaction.CONCLUSIONS:
Sam68 promotes pro-inflammatory response in injured arteries and impedes recovery by interacting with FLNA to stabilize TRAF2 on the cytoskeleton and consequently potentiate NF-κB signaling.Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Arterias Carótidas
/
Proteínas de Unión al ARN
/
Proteínas Adaptadoras Transductoras de Señales
/
Inflamación
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Mol Cell Cardiol
Año:
2019
Tipo del documento:
Article
País de afiliación:
Estados Unidos