CREB mediates UTP-directed arterial smooth muscle cell migration and expression of the chemotactic protein osteopontin via its interaction with activator protein-1 sites.
The transcription factor cAMP responsive element-binding protein (CREB) has been found to be involved in arterial smooth muscle cell (SMC) migration. We previously demonstrated that osteopontin (OPN) expression is a key step for UTP-mediated migration of arterial SMCs and that activator protein (AP)-1, nuclear factor kappaB, and upstream stimulatory transcription factors are involved in this OPN expression. The present study aims to determine the role of CREB in UTP-induced migration and OPN expression in cultured SMCs. We found that CREB is activated by UTP via extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase pathways but not by protein kinase A. Both overexpression of a dominant negative CREB and CREB small interfering RNA treatment suppressed UTP-induced OPN expression and SMC migration. Gel-shift and chromatin immunoprecipitation assays revealed that CREB binds 2 AP-1 sites (-1870 and -76) and a cAMP responsive element-like site (-1403) on the OPN promoter. Mutations of these sites showed that only the 2 AP-1 sites were required for UTP-induced OPN expression. Moreover, gel-supershift and sequential chromatin immunoprecipitation assays suggested that CREB was associated with c-Fos on the AP-1 sites of the OPN promoter. These results demonstrate that CREB participates in the induction of UTP-activated OPN expression via its binding to 2 AP-1 sites and is thus involved in UTP-mediated SMC migration.
Jalvy
Sandra
S
INSERM U441, Pessac, France.
Renault
Marie-Ange
MA
Lam Shang Leen
Laetitia
L
Belloc
Isabelle
I
Reynaud
Annabel
A
Gadeau
Alain-Pierre
AP
Desgranges
Claude
C
D002465:Cell Movement; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology; D020935:MAP Kinase Signaling System / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000166:cytology*; D053495:Osteopontin / Q000235:genetics*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D020218:Response Elements; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014544:Uridine Triphosphate / Q000494:pharmacology*
D017362:Cyclic AMP Response Element-Binding Protein; D012333:RNA, Messenger; D018808:Transcription Factor AP-1; D053495:Osteopontin; D017868:Cyclic AMP-Dependent Protein Kinases; D014544:Uridine Triphosphate