title: The calcineurin-nuclear factor of activated T cells signaling pathway mediates the effect of corticotropin releasing factor and urocortins on catecholamine synthesis.
abstract: The biological effects of the Corticotropin-releasing factor (CRF) family of neuropeptides are mediated by mobilization of [Ca(2+)]. Aim of the current work was to examine if the calcineurin/NFAT (nuclear factor of activated T-cells) signaling pathway is involved in the effect of CRF peptides in catecholamine synthesis and secretion from PC12 rat pheochromocytona cells, a model for the study of adrenal catecholamine production. PC12 cells express both types of CRF receptors. Our data are as follows: (a) The calcineurin inhibitor cyclosporine A (CsA) blocked norepinephrine secretion induced by ligands of either CRF type 1 (CRF(1)) or 2 (CRF(2)) receptors on PC12 cells. (b) Silencing NFAT2 expression using a selective NFAT2 siRNA blocked CRF(1) and CRF(2) -induced NE production. (c) CRF ligands induced NFAT transcriptional activity in cells transfected with a luciferase reporter construct controlled by NFAT binding elements (NFAT-Luc). (d) CsA completely blocked the stimulatory effect of CRF(1) and CRF(2) ligands on NFAT activity in NFAT-Luc transfected cells. (e) PKA, PKC, p38-MAPK, Tpl2, Ha-Ras, and AKT1 were crucial intermediates for both CRF(1) and CRF(2)-induced NFAT activation. Interestingly, MEK1/2 and ERK1/2 were crucial only for the CRF(2)-induced NFAT activation. (f) p38-MAPK and Tpl2 were crucial intermediates for both CRF(1) and CRF(2)-induced norepinephrine production, while AKT1 affected only CRF(2)-induced norepinephrine production. In conclusion, our data suggest that CRF(1) and CRF(2) ligands activate the transcription factor NFAT and its activation is prerequisite for CRF-induced catecholamine production from chromaffin cells.
authors.affiliation: Department of Clinical Chemistry-Biochemistry, School of Medicine, University of Crete, Heraklion, Crete, Greece.
authors.forename: Eirini
authors.initials: E
authors.lastname: Dermitzaki
authors.forename: Christos
authors.initials: C
authors.lastname: Tsatsanis
authors.forename: Achille
authors.initials: A
authors.lastname: Gravanis
authors.forename: Andrew N
authors.initials: AN
authors.lastname: Margioris
mesh_terms: D000818:Animals; D019703:Calcineurin / Q000378:metabolism*; D002395:Catecholamines / Q000096:biosynthesis* / Q000378:metabolism; D003346:Corticotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism*; D016572:Cyclosporine / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005260:Female; D006801:Humans; D050778:NFATC Transcription Factors / Q000235:genetics / Q000378:metabolism*; D016716:PC12 Cells; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D051381:Rats; D018019:Receptors, Corticotropin-Releasing Hormone / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*; D054832:Urocortins / Q000235:genetics / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D000099052:CRF Receptor, Type 1
chemical_list: C101531:CRF receptor type 2; D002395:Catecholamines; D004791:Enzyme Inhibitors; D050778:NFATC Transcription Factors; D020033:Protein Isoforms; D034741:RNA, Small Interfering; D018019:Receptors, Corticotropin-Releasing Hormone; D011993:Recombinant Fusion Proteins; D054832:Urocortins; C488590:cortagine; D000099052:CRF Receptor, Type 1; D016572:Cyclosporine; D003346:Corticotropin-Releasing Hormone; D019869:Phosphatidylinositol 3-Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D019703:Calcineurin