Reactive oxygen species and ERK 1/2 mediate monocyte chemotactic protein-1-stimulated smooth muscle cell migration.
J Biomed Sci
; 12(2): 377-88, 2005.
Article
en En
| MEDLINE
| ID: mdl-15917991
ABSTRACT
Monocyte chemotactic protein-1 (MCP-1), a potent chemoattractant for monocytes, is thought to play a major role in atherosclerosis, but whether its atherogenic effects involve the direct modulation of vascular smooth muscle cell (SMC) functions remains unclear. This study examined the effects of MCP-1 on the migration of cultured A7r5 SMCs and the signaling pathways involved. Addition of recombinant MCP-1 stimulated SMC migration in modified Boyden chambers coated with type I collagen in a concentration-dependent manner, with 10(-9) M being maximally effective. Using untreated A7r5 cells, two MCP-1 receptors, CCR2 and CCR4, were detected and MCP-1 secretion was significantly increased by stimulation with platelet-derived growth factor. MCP-1-stimulated A7r5 migration was completely blocked by the NAD(P)H oxidase inhibitor, diphenylene iodonium (DPI), and dose-dependently inhibited by polyethylene glycol-conjugated superoxide dismutase (PEG-SOD), suggesting a role for reactive oxygen species (ROS) in this process. During MCP-1 stimulation, ROS production increased rapidly, then gradually decayed over 60 min, and this effect was markedly decreased by pretreatment with DPI or PEG-SOD. Interestingly, U0126 and PD98059, which inhibit activation of extracellular signal-regulated kinases 1/2 (ERK 1/2), significantly inhibited MCP-1-activated ROS generation. Furthermore, transfection of an active mutant of MEK1 (ERK 1/2 kinase) markedly increased superoxide production in rat aortic smooth muscle cells, as detected by dihydroethydium staining, suggesting that ERK 1/2 activation stimulates ROS generation. ERK 1/2 activation was increased for at least 30 min in cells incubated with MCP-1, and this effect was abolished by U0126 or DPI pretreatment. These results demonstrate that MCP-1 is a chemoattractant for SMCs and that MCP-1-stimulated migration requires both ROS production and ERK 1/2 activation in a positive activation loop, which may contribute to the atherogenic effects of MCP-1.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Especies Reactivas de Oxígeno
/
Quimiocina CCL2
/
Proteína Quinasa 1 Activada por Mitógenos
/
Miocitos del Músculo Liso
/
Proteína Quinasa 3 Activada por Mitógenos
Límite:
Animals
Idioma:
En
Revista:
J Biomed Sci
Asunto de la revista:
MEDICINA
Año:
2005
Tipo del documento:
Article
País de afiliación:
Taiwán