TY - JOUR
T1 - MCP-1-dependent signaling in CCR2-/- aortic smooth muscle cells
AU - Schecter, Alison D.
AU - Berman, Adriane B.
AU - Yi, Lin
AU - Ma, Harry
AU - Daly, Christine M.
AU - Soejima, Kenzo
AU - Rollins, Barrett J.
AU - Charo, Israel F.
AU - Taubman, Mark B.
PY - 2004/6
Y1 - 2004/6
N2 - Monocyte chemoattractant protein-1 (MCP-1, CCL2) is a mediator of inflammation that has been implicated in the pathogenesis of a wide variety of human diseases. CCR2, a heterotrimeric G-coupled receptor, is the only known receptor that functions at physiologic concentrations of MCP-1. Despite the importance of CCR2 in mediating MCP-1 responses, several recent studies have suggested that there may be another functional MCP-1 receptor. Using arterial smooth muscle cells (SMC) from CCR2-/- mice, we demonstrate that MCP-1 induces tissue-factor activity at physiologic concentrations. The induction of tissue factor by MCP-1 is blocked by pertussis toxin and 1,2-bis(O-aminophenyl-ethane-ethan)-N,N,N′,N′-tetraacetic acid-acetoxymethyl ester, suggesting that signal transduction through the alternative receptor is Gαi-coupled and dependent on mobilization of intracellular Ca2+. MCP-1 induces a time-and concentration-dependent phosphorylation of the mitogen-activated protein kinases p42/44. The induction of tissue factor activity by MCP-1 is blocked by PD98059, an inhibitor of p42/44 activation, but not by SB203580, a selective p38 inhibitor. These data establish that SMC possess an alternative MCP-1 receptor that signals at concentrations of MCP-1 that are similar to those that activate CCR2. This alternative receptor may be important in mediating some of the effects of MCP-1 in atherosclerotic arteries and in other inflammatory processes.
AB - Monocyte chemoattractant protein-1 (MCP-1, CCL2) is a mediator of inflammation that has been implicated in the pathogenesis of a wide variety of human diseases. CCR2, a heterotrimeric G-coupled receptor, is the only known receptor that functions at physiologic concentrations of MCP-1. Despite the importance of CCR2 in mediating MCP-1 responses, several recent studies have suggested that there may be another functional MCP-1 receptor. Using arterial smooth muscle cells (SMC) from CCR2-/- mice, we demonstrate that MCP-1 induces tissue-factor activity at physiologic concentrations. The induction of tissue factor by MCP-1 is blocked by pertussis toxin and 1,2-bis(O-aminophenyl-ethane-ethan)-N,N,N′,N′-tetraacetic acid-acetoxymethyl ester, suggesting that signal transduction through the alternative receptor is Gαi-coupled and dependent on mobilization of intracellular Ca2+. MCP-1 induces a time-and concentration-dependent phosphorylation of the mitogen-activated protein kinases p42/44. The induction of tissue factor activity by MCP-1 is blocked by PD98059, an inhibitor of p42/44 activation, but not by SB203580, a selective p38 inhibitor. These data establish that SMC possess an alternative MCP-1 receptor that signals at concentrations of MCP-1 that are similar to those that activate CCR2. This alternative receptor may be important in mediating some of the effects of MCP-1 in atherosclerotic arteries and in other inflammatory processes.
KW - Chemokine
KW - Genetically altered mice
KW - Kinases
KW - Receptors
KW - Tissue factor
KW - Vascular smooth muscle
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U2 - 10.1189/jlb.0903421
DO - 10.1189/jlb.0903421
M3 - Article
C2 - 15020650
AN - SCOPUS:2642586618
VL - 75
SP - 1079
EP - 1085
JO - Journal of Leukocyte Biology
JF - Journal of Leukocyte Biology
SN - 0741-5400
IS - 6
ER -