Store-operated Ca2+ entry activates the CREB transcription factor in vascular smooth muscle.
Ca2+-regulated gene transcription is a critical component of arterial responses to injury, hypertension, and tumor-stimulated angiogenesis. The Ca2+/cAMP response element binding protein (CREB), a transcription factor that regulates expression of many genes, is activated by Ca2+-induced phosphorylation. Multiple Ca2+ entry pathways may contribute to CREB activation in vascular smooth muscle including voltage-dependent Ca2+ channels and store-operated Ca2+ entry (SOCE). To investigate a role for SOCE in CREB activation, we measured CREB phosphorylation using immunofluorescence, intracellular Ca2+ levels using a fluorescence resonance energy transfer (FRET)-based Cameleon indicator, and c-fos transcription using RT-PCR. In this study, we report that SOCE activates CREB in both cultured smooth muscle cells and intact arteries. Depletion of intracellular Ca2+ stores with thapsigargin increased nuclear phospho-CREB levels, intracellular Ca2+ concentration, and transcription of c-fos. These effects were abolished by inhibiting SOCE through lowering extracellular Ca2+ concentration or by application of 2-aminoethoxydiphenylborate and Ni2+. Inhibition of Ca2+ influx through voltage-dependent Ca2+ channels using nimodipine partially blocked intact artery responses, but was without effect in cultured smooth muscle cells. Our findings indicate that Ca2+ entry through store-operated Ca2+ channels leads to CREB activation, suggesting that SOCE contributes to the regulation of gene expression in vascular smooth muscle.
Pulver
Renee A
RA
Department of Pharmacology, University of Vermont, Burlington, VT 05405, USA.
Rose-Curtis
Patricia
P
Roe
Michael W
MW
Wellman
George C
GC
Lounsbury
Karen M
KM
D000818:Animals; D001158:Arteries / Q000166:cytology / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000502:physiology*; D020746:Calcium Channels, L-Type / Q000378:metabolism; D020013:Calcium Signaling; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation; D017136:Ion Transport; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism*; D010766:Phosphorylation; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D019284:Thapsigargin / Q000494:pharmacology
D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D017362:Cyclic AMP Response Element-Binding Protein; D004791:Enzyme Inhibitors; D016760:Proto-Oncogene Proteins c-fos; D019284:Thapsigargin; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D000252:Calcium-Transporting ATPases; D002118:Calcium