Intraluminal pressure is a stimulus for NFATc3 nuclear accumulation: role of calcium, endothelium-derived nitric oxide, and cGMP-dependent protein kinase.
The transcription factor NFAT (nuclear factor of activated T-cells) is implicated in cardiac hypertrophy and vasculogenesis. NFAT activation, reflecting dephosphorylation by the calcium-dependent phosphatase, calcineurin, and subsequent nuclear localization, is generally thought to require a sustained increase in intracellular calcium. However, in smooth muscle we have found that elevation of calcium by membrane depolarization fails to induce an increase in nuclear localization of the NFATc3 isoform. Here, we demonstrate that physiological intravascular pressure (100 mm Hg) induces an increase in NFATc3 nuclear localization in mouse cerebral arteries. Pressure-induced NFATc3 nuclear accumulation is abrogated by endothelial denudation and by nitric-oxide synthase, cGMP-dependent kinase (PKG), and voltage-dependent calcium channels inhibition. We further show that exogenous nitric oxide, in combination with an elevation in calcium, is an effective stimulus for NFATc3 nuclear accumulation. c-Jun terminal kinase 2 (JNK) activity, which has been shown to regulate NFATc3 nuclear export, is also reduced by pressure, an effect that is prevented by pretreatment with a PKG inhibitor. Consistent with this, pressure-induced NFATc3 nuclear accumulation is independent of PKG in arteries from JNK2(-/-) mice. Collectively, our results indicate that both activation of the NO/PKG pathway and elevation of smooth muscle calcium are required for NFATc3 nuclear accumulation and that PKG inhibits JNK2 to decrease NFAT nuclear export. Our findings suggest that at physiological intravascular pressures NFATc3 is localized to the nucleus in smooth muscle cells of intact arteries and indicate a novel and unexpected role for nitric oxide/PKG in NFAT activation.
Gonzalez Bosc
Laura V
LV
Department of Pharmacology, College of Medicine, University of Vermont, Burlington 05405, USA.
Wilkerson
Michael K
MK
Bradley
Karen N
KN
Eckman
Delrae M
DM
Hill-Eubanks
David C
DC
Nelson
Mark T
MT
D021581:Active Transport, Cell Nucleus; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D002478:Cells, Cultured; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D004730:Endothelium, Vascular / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D048056:Mitogen-Activated Protein Kinase 9; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008954:Models, Biological; D009130:Muscle, Smooth / Q000196:embryology / Q000378:metabolism; D050778:NFATC Transcription Factors; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism; D010766:Phosphorylation; D011188:Potassium / Q000378:metabolism; D011312:Pressure; D020033:Protein Isoforms; D021381:Protein Transport; D013997:Time Factors; D014157:Transcription Factors / Q000096:biosynthesis*
D004268:DNA-Binding Proteins; D050778:NFATC Transcription Factors; C494009:Nfatc3 protein, mouse; D020033:Protein Isoforms; D014157:Transcription Factors; C445503:transcription factor NF-AT c3; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D048056:Mitogen-Activated Protein Kinase 9; D017869:Cyclic GMP-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D011188:Potassium; D002118:Calcium