title: Guanylyl cyclase/natriuretic peptide receptor-A signaling antagonizes the vascular endothelial growth factor-stimulated MAPKs and downstream effectors AP-1 and CREB in mouse mesangial cells.
abstract: Along with its natriuretic, diuretic, and vasodilatory properties, atrial natriuretic peptide (ANP), and its guanylyl cyclase/natriuretic peptide receptor-A (GC-A/NPRA) exhibit an inhibitory effect on cell growth and proliferation. However, the signaling pathways mediating this inhibition are not well understood. The objective of this study was to determine the effect of ANP-NPRA system on mitogen-activated protein kinases (MAPKs) and the downstream proliferative transcription factors involving activating protein-1 (AP-1) and cAMP-response element binding protein (CREB) in agonist-stimulated mouse mesangial cells (MMCs). We found that ANP inhibited vascular endothelial growth factor (VEGF)-stimulated phosphorylation of MAPKs (Erk1, Erk2, JNK, and p38), to a greater extent in NPRA-transfected cells (50-60 %) relative to vector-transfected cells (25-30 %). The analyses of the phosphorylated transcription factors revealed that ANP inhibited VEGF-stimulated activation of CREB, and the AP-1 subunits (c-jun and c-fos). Gel shift assays demonstrated that ANP inhibited VEGF-stimulated AP-1 and CREB DNA-binding ability by 67 and 62 %, respectively. The addition of the protein kinase G (PKG) inhibitor, KT-5823, restored the VEGF-stimulated activation of MAPKs, AP-1, and CREB, demonstrating the integral role of cGMP/PKG signaling in NPRA-mediated effects. Our results delineate the underlying mechanisms through which ANP-NPRA system exerts an inhibitory effect on MAPKs and down-stream effector molecules, AP-1, and CREB, critical for cell growth and proliferation.
authors.affiliation: Department of Physiology, Tulane University Health Sciences Center, School of Medicine, SL-39, New Orleans, LA, 70112, USA.
authors.forename: Satyabha
authors.initials: S
authors.lastname: Tripathi
authors.forename: Kailash N
authors.initials: KN
authors.lastname: Pandey
mesh_terms: D000818:Animals; D009320:Atrial Natriuretic Factor / Q000235:genetics / Q000378:metabolism; D002227:Carbazoles / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism*; D006152:Cyclic GMP / Q000235:genetics / Q000378:metabolism; D017869:Cyclic GMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism*; D005920:Glomerular Mesangium / Q000166:cytology / Q000378:metabolism*; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D017461:Receptors, Atrial Natriuretic Factor / Q000235:genetics / Q000378:metabolism*; D015290:Second Messenger Systems / Q000187:drug effects / Q000502:physiology*; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D002227:Carbazoles; C492004:Creb1 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; D047428:Protein Kinase Inhibitors; D018808:Transcription Factor AP-1; D042461:Vascular Endothelial Growth Factor A; C467480:vascular endothelial growth factor A, mouse; C073601:KT 5823; D009320:Atrial Natriuretic Factor; D017869:Cyclic GMP-Dependent Protein Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D017461:Receptors, Atrial Natriuretic Factor; C091715:atrial natriuretic factor receptor A; D006152:Cyclic GMP