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Kutsukake M, Kuwabara N, Miyate Y, Kudo K, Goto S, Taira E, Tachikawa E. Relationship between Ca 2+ and cAMP as second messengers in ACTH-induced cortisol production in bovine adrenal fasciculata cells. Endocr J 2023; 70:1123-1130. [PMID: 37793884 DOI: 10.1507/endocrj.ej23-0253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/06/2023] Open
Abstract
In adrenal fasciculata cells stimulated by ACTH, Ca2+ and cAMP play indispensable roles as second messengers in cortisol production. However, whether their second messengers cooperatively or independently participate in steroid production remains unclear. We focused on the roles of Ca2+ and cAMP in cortisol production in bovine adrenal fasciculata cells stimulated by ACTH for a relatively short period (1 h). Incubation of the cells with 100 pM ACTH in Ca2+-containing (normal) medium for 1 h increased cortisol production without affecting cAMP content. In contrast, treatment of the cells with the peptide at a higher concentration (1 nM) significantly augmented both cortisol production and cAMP content. However, ACTH did not increase either of them in the Ca2+-free medium. ACTH rapidly increased the intracellular free Ca2+ concentration ([Ca2+]i) in the normal medium, but did not influence [Ca2+]i in the Ca2+-free medium, indicating that ACTH caused Ca2+ influx into the cells. ACTH-induced Ca2+ influx and cortisol production were suppressed by a voltage-sensitive L-type Ca2+ channel blocker but not by a T-type, N-type, or P-type Ca2+ channel blocker. In contrast, dibutyryl cAMP, a cell-permeable cAMP analog, greatly enhanced cortisol production in the normal or Ca2+-free medium and slowly caused Ca2+ influx into the cells. These results strongly suggest that Ca2+, as a second messenger, is more critical than cAMP for cortisol production. However, both second messengers jointly participate in the production in adrenal fasciculata cells stimulated by ACTH.
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Affiliation(s)
- Masahiko Kutsukake
- Unaduki Pharmacy, Toyama 938-0862, Japan
- Department of Endocrine & Neural Pharmacology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan
| | - Naoko Kuwabara
- Department of Endocrine & Neural Pharmacology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan
- Department of Bio-analytical Chemistry, Faculty of Pharmacy, Niigata University of Pharmacy and Applied Life Sciences, Niigata 956-8603, Japan
| | - Yoshikazu Miyate
- Department of Pharmacology, School of Medicine, Iwate Medical University, Iwate 028-3694, Japan
| | - Kenzo Kudo
- Division of Clinical Pharmaceutics and Pharmacy Practice, Department of Clinical Pharmacy, School of Pharmacy, Iwate Medical University, Iwate 028-3694, Japan
| | - Shoko Goto
- Takizawa Laboratory Administration Section, Radioactive Waste Management Division, Japan Radioisotope Association, Iwate 020-0603, Japan
| | - Eiichi Taira
- Department of Pharmacology, School of Medicine, Iwate Medical University, Iwate 028-3694, Japan
| | - Eiichi Tachikawa
- Department of Endocrine & Neural Pharmacology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan
- Division of Clinical Pharmaceutics and Pharmacy Practice, Department of Clinical Pharmacy, School of Pharmacy, Iwate Medical University, Iwate 028-3694, Japan
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Smith LIF, Huang V, Olah M, Trinh L, Liu Y, Hazell G, Conway-Campbell B, Zhao Z, Martinez A, Lefrançois-Martinez AM, Lightman S, Spiga F, Aguilera G. Involvement of CREB-regulated transcription coactivators (CRTC) in transcriptional activation of steroidogenic acute regulatory protein (Star) by ACTH. Mol Cell Endocrinol 2020; 499:110612. [PMID: 31604124 PMCID: PMC6899503 DOI: 10.1016/j.mce.2019.110612] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/06/2019] [Accepted: 10/04/2019] [Indexed: 12/20/2022]
Abstract
Studies in vivo have suggested the involvement of CREB-regulated transcription coactivator (CRTC)2 on ACTH-induced transcription of the key steroidogenic protein, Steroidogenic Acute Regulatory (StAR). The present study uses two ACTH-responsive adrenocortical cell lines, to examine the role of CRTC on Star transcription. Here we show that ACTH-induced Star primary transcript, or heteronuclear RNA (hnRNA), parallels rapid increases in nuclear levels of the 3 isoforms of CRTC; CRTC1, CRTC2 and CRTC3. Furthermore, ACTH promotes recruitment of CRTC2 and CRTC3 by the Star promoter and siRNA knockdown of either CRTC3 or CRTC2 attenuates the increases in ACTH-induced Star hnRNA. Using pharmacological inhibitors of PKA, MAP kinase and calcineurin, we show that the effects of ACTH on Star transcription and CRTC nuclear translocation depend predominantly on the PKA pathway. The data provides evidence that CRTC2 and CRTC3, contribute to activation of Star transcription by ACTH, and that PKA/CRTC-dependent pathways are part of the multifactorial mechanisms regulating Star transcription.
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Affiliation(s)
- Lorna I F Smith
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA; Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK.
| | - Victoria Huang
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Mark Olah
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Loc Trinh
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Ying Liu
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
| | - Georgina Hazell
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Becky Conway-Campbell
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Zidong Zhao
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Antoine Martinez
- Génétique Reproduction & Développement, CNRS UMR 6293, Inserm U1103, Université Clermont Auvergne, 63001, Clermont-Ferrand, France
| | - Anne-Marie Lefrançois-Martinez
- Génétique Reproduction & Développement, CNRS UMR 6293, Inserm U1103, Université Clermont Auvergne, 63001, Clermont-Ferrand, France
| | - Stafford Lightman
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Francesca Spiga
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, University of Bristol, Bristol, UK
| | - Greti Aguilera
- Section on Endocrine Physiology, Program on Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD, USA
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Oh J, Kim DH, Kim GY, Park EJ, Ryu JH, Jung JW, Park SJ, Kim GW, Lee S. Hydrangeae Dulcis Folium Attenuates Physical Stress by Supressing ACTH-Induced Cortisol in Zebrafish. Chin J Integr Med 2019; 26:130-137. [DOI: 10.1007/s11655-019-3204-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2018] [Indexed: 12/11/2022]
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Abstract
Phospholipases are lipid-metabolizing enzymes that hydrolyze phospholipids. In some cases, their activity results in remodeling of lipids and/or allows the synthesis of other lipids. In other cases, however, and of interest to the topic of adrenal steroidogenesis, phospholipases produce second messengers that modify the function of a cell. In this review, the enzymatic reactions, products, and effectors of three phospholipases, phospholipase C, phospholipase D, and phospholipase A2, are discussed. Although much data have been obtained concerning the role of phospholipases C and D in regulating adrenal steroid hormone production, there are still many gaps in our knowledge. Furthermore, little is known about the involvement of phospholipase A2, perhaps, in part, because this enzyme comprises a large family of related enzymes that are differentially regulated and with different functions. This review presents the evidence supporting the role of each of these phospholipases in steroidogenesis in the adrenal cortex.
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Affiliation(s)
- Wendy B Bollag
- Charlie Norwood VA Medical CenterOne Freedom Way, Augusta, GA, USA Department of PhysiologyMedical College of Georgia, Augusta University (formerly Georgia Regents University), Augusta, GA, USA
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Nishikawa T, Suematsu S, Matsuzawa Y, Saito J, Omura M. Guanosine triphosphate can directly regulate cortisol production by activating Ca(2+)-messenger systems in bovine adrenal fasciculata cells. Endocr J 2016; 63:77-85. [PMID: 26560437 DOI: 10.1507/endocrj.ej15-0393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Adenosine triphosphate (ATP) is known to stimulate cortisol production in vitro, however, the effect of guanosine triphosphate (GTP) on cortisol production is not known. We studied the effect of GTP on cortisol production and investigated the regulation of intracellular signal transduction systems, including the cyclic AMP-dependent and Ca(2+)-messenger systems, in bovine adrenal fasciculata cells. GTP clearly induced cortisol biosynthesis but only to a level less than half the adrenocorticotropic hormone (ACTH)-induced maximum. The binding site for [γ-(35)S]-GTPγS was shown to differ completely from that for ATP and also from those for Gs and Gi, as indicated by the fact that binding was not influenced by pretreatment with cholera toxin and pertussis toxin. GTP significantly increased cytosolic calcium ([Ca(2+)]i) and inositol 1, 4, 5-triphosphate without affecting cyclic AMP formation. GTP-induced cortisol production was suppressed by H-9 and Calphostin C (specific protein kinase C inhibitors) but not by H-8 and KT5720 (specific inhibitors of cyclic AMP-dependent protein kinase), suggesting that GTP activates cortisol biosynthesis possibly via a protein kinase C-dependent pathway. Extracellular calcium may be essential for GTP activity since GTP-induced cortisol production was almost completely suppressed in its absence. In conclusion, it can be postulated that GTP-induced steroid secretion in bovine adrenal fasciculata cells is under paracrine or autocrine control.
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Affiliation(s)
- Tetsuo Nishikawa
- Endocrinology and Diabetes Center, Yokohama Rosai Hospital, Yokohama, Japan
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Enyeart JJ, Enyeart JA. Ca2+ and K+ channels of normal human adrenal zona fasciculata cells: properties and modulation by ACTH and AngII. ACTA ACUST UNITED AC 2013; 142:137-55. [PMID: 23858003 PMCID: PMC3727308 DOI: 10.1085/jgp.201310964] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
In whole cell patch clamp recordings, we found that normal human adrenal zona fasciculata (AZF) cells express voltage-gated, rapidly inactivating Ca2+ and K+ currents and a noninactivating, leak-type K+ current. Characterization of these currents with respect to voltage-dependent gating and kinetic properties, pharmacology, and modulation by the peptide hormones adrenocorticotropic hormone (ACTH) and AngII, in conjunction with Northern blot analysis, identified these channels as Cav3.2 (encoded by CACNA1H), Kv1.4 (KCNA4), and TREK-1 (KCNK2). In particular, the low voltage–activated, rapidly inactivating and slowly deactivating Ca2+ current (Cav3.2) was potently blocked by Ni2+ with an IC50 of 3 µM. The voltage-gated, rapidly inactivating K+ current (Kv1.4) was robustly expressed in nearly every cell, with a current density of 95.0 ± 7.2 pA/pF (n = 64). The noninactivating, outwardly rectifying K+ current (TREK-1) grew to a stable maximum over a period of minutes when recording at a holding potential of −80 mV. This noninactivating K+ current was markedly activated by cinnamyl 1-3,4-dihydroxy-α-cyanocinnamate (CDC) and arachidonic acid (AA) and inhibited almost completely by forskolin, properties which are specific to TREK-1 among the K2P family of K+ channels. The activation of TREK-1 by AA and inhibition by forskolin were closely linked to membrane hyperpolarization and depolarization, respectively. ACTH and AngII selectively inhibited the noninactivating K+ current in human AZF cells at concentrations that stimulated cortisol secretion. Accordingly, mibefradil and CDC at concentrations that, respectively, blocked Cav3.2 and activated TREK-1, each inhibited both ACTH- and AngII-stimulated cortisol secretion. These results characterize the major Ca2+ and K+ channels expressed by normal human AZF cells and identify TREK-1 as the primary leak-type channel involved in establishing the membrane potential. These findings also suggest a model for cortisol secretion in human AZF cells wherein ACTH and AngII receptor activation is coupled to membrane depolarization and the activation of Cav3.2 channels through inhibition of hTREK-1.
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Affiliation(s)
- John J Enyeart
- Department of Neuroscience, The Ohio State University Wexner Medical Center, Columbus, OH 43210, USA.
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Böhm M, Grässel S. Role of proopiomelanocortin-derived peptides and their receptors in the osteoarticular system: from basic to translational research. Endocr Rev 2012; 33:623-51. [PMID: 22736674 PMCID: PMC3410228 DOI: 10.1210/er.2011-1016] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Proopiomelanocortin (POMC)-derived peptides such as melanocortins and β-endorphin (β-ED) exert their pleiotropic effects via binding to melanocortin receptors (MCR) and opioid receptors (OR). There is now compelling evidence for the existence of a functional POMC system within the osteoarticular system. Accordingly, distinct cell types of the synovial tissue and bone have been identified to generate POMC-derived peptides like β-ED, ACTH, or α-MSH. MCR subtypes, especially MC1R, MC2R (the ACTH receptor), MC3R, and MC4R, but also the μ-OR and δ-OR, have been detected in various cells of the synovium, cartilage, and bone. The respective ligands of these POMC-derived peptide receptors mediate an increasing number of newly recognized biological effects in the osteoarticular system. These include bone mineralization and longitudinal growth, cell proliferation and differentiation, extracellular matrix synthesis, osteoprotection, and immunomodulation. Importantly, bone formation is also regulated by the central melanocortin system via a complex hormonal interplay with other organs and tissues involved in energy metabolism. Among the POMC-derived peptides examined in cell culture systems from osteoarticular tissue and in animal models of experimentally induced arthritis, α-MSH, ACTH, and MC3R-specific agonists appear to have the most promising antiinflammatory actions. The effects of these melanocortin peptides may be exploited in future for the treatment of patients with inflammatory and degenerative joint diseases.
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Affiliation(s)
- Markus Böhm
- Laboratory for Neuroendocrinology of the Skin and Interdisciplinary Endocrinology, Department of Dermatology, University of Münster, Von Esmarch-Strasse 58, D-48149 Münster, Germany.
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Enyeart JJ, Liu H, Enyeart JA. Evidence for cAMP-independent bTREK-1 inhibition by ACTH and NPS-ACTH in adrenocortical cells. Mol Cell Endocrinol 2012; 348:305-12. [PMID: 21952081 DOI: 10.1016/j.mce.2011.09.023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 08/30/2011] [Accepted: 09/09/2011] [Indexed: 11/26/2022]
Abstract
Bovine adrenal zona fasciculata (AZF) cells express bTREK-1 K(+) channels that are inhibited by ACTH through cAMP-dependent pathways. In whole cell patch clamp recordings from AZF cells, we found that ACTH may also inhibit bTREK-1 by a cAMP-independent mechanism. When the potent adenylyl cyclase (AC) antagonist 2,5-dideoxyadenosine-3'-triphosphate (2,5-dd-3'-ATP) was applied intracellularly through the patch pipette, bTREK-1 inhibition by the AC activator forskolin was blocked. In contrast, bTREK-1 inhibition by ACTH was unaltered. The selective G(Sα) antagonist NF449 also failed to blunt bTREK-1 inhibition by ACTH. At concentrations that produce little measurable increase in cAMP in bovine AZF cells, the O-nitrophenyl, sulfenyl-derivative of ACTH (NPS-ACTH) also inhibited bTREK-1 almost completely. Accordingly, 2,5-dd-3'-ATP at concentrations more than 1000× its reported IC(50) did not block bTREK-1 inhibition by NPS-ACTH. These results indicate that ACTH and NPS-ACTH can inhibit native bTREK-1 K(+) channels in AZF cells by a mechanism that does not involve activation of AC.
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Affiliation(s)
- John J Enyeart
- Department of Neuroscience, The Ohio State University, College of Medicine and Public Health, Columbus, OH 43210-1239, USA.
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Enyeart JA, Liu H, Enyeart JJ. 8-Phenylthio-adenines stimulate the expression of steroid hydroxylases, Cav3.2 Ca²⁺ channels, and cortisol synthesis by a cAMP-independent mechanism. Am J Physiol Endocrinol Metab 2011; 301:E941-54. [PMID: 21810929 PMCID: PMC3213996 DOI: 10.1152/ajpendo.00282.2011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The regulation of cortisol synthesis and the expression of genes coding for steroidogenic proteins by 8-substituted cAMP and 8-substituted adenine derivatives were studied in bovine adrenal zona fasciculata (AZF) cells. At concentrations of 10-50 μM, 8-(4-chlorophenylthio)-cAMP (8CPT-cAMP), but not the poorly hydrolyzable Sp-8CPT-cAMP, stimulated large increases in cortisol synthesis and CYP17 mRNA expression. Of the three Epac (exchange protein activated by cAMP)-specific cAMP analogs, 8CPT-2'-OMe-cAMP, but not 8HPT-2'-OMe-cAMP or 8MeOPT-2'-OMe-cAMP, induced mRNAs for CYP17 and CYP11a1 steroid hydroxylases and stimulated cortisol synthesis. 8-Substituted adenine derivatives (10-200 μM), including 8PT-adenine, 8MeOPT-adenine, and 8CPT-adenine, stimulated similar large, concentration-dependent, and reversible increases in cortisol synthesis and steroid hydroxylase gene expression, whereas 8Br-adenine was ineffective. The phenylthio-adenine derivatives produced additive effects on cortisol synthesis when applied to AZF cells in combination with 8Br-cAMP. In contrast, no additivity was observed for these three compounds when used in combination with ACTH. 8PT-adenine did not activate PKA or inhibit DNA synthesis by AZF cells. 8PT-adenine-stimulated cortisol secretion and CYP17 steroid hydroxylase mRNA expression were potently inhibited by diphenyl-butylpiperidine T-type Ca(2+) antagonists. In AZF cells, 8PT-adenine and 8MeOPT-adenine induced the expression of both CACNA1H mRNA and associated Ca(v)3.2 Ca(2+) current. These results indicate that 8-chloro (but not 8-hydroxy- or 8-methoxy-)-phenylthio-cAMP analogs are converted to an active metabolite, 8CPT-adenine, that induces the expression of genes coding for steroidogenic proteins in bovine AZF cells. Other PT-adenine analogs also potently stimulate cortisol synthesis through the same unidentified signaling pathway that requires the expression of functional Ca(v)3.2 Ca(2+) channels. These phenylthio-adenine compounds and ACTH may stimulate cortisol synthesis through the same cAMP-independent mechanism.
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Affiliation(s)
- Judith A Enyeart
- Department of Neuroscience, The Ohio State University College of Medicine and Public Health, Columbus, Ohio 43210-1269, USA
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Liu H, Enyeart JA, Enyeart JJ. ACTH induces Cav3.2 current and mRNA by cAMP-dependent and cAMP-independent mechanisms. J Biol Chem 2010; 285:20040-50. [PMID: 20424171 DOI: 10.1074/jbc.m110.104190] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Bovine adrenal zona fasciculata (AZF) cells express Ca(v)3.2 T-type Ca(2+) channels that function pivotally in adrenocorticotropic hormone (ACTH)-stimulated cortisol secretion. The regulation of Ca(v)3.2 expression in AZF cells by ACTH, cAMP analogs, and their metabolites was studied using Northern blot and patch clamp recording. Exposing AZF cells to ACTH for 3-6 days markedly enhanced the expression of Ca(v)3.2 current. The increase in Ca(v)3.2 current was preceded by an increase in corresponding CACNA1H mRNA. O-Nitrophenyl,sulfenyl-adrenocorticotropin, which produces a minimal increase in cAMP, also enhanced Ca(v)3.2 current. cAMP analogs, including 8-bromoadenosine cAMP (600 mum) and 6-benzoyladenosine cAMP (300 mum) induced CACNA1H mRNA, but not Ca(v)3.2 current. In contrast, 8-(4-chlorophenylthio) (8CPT)-cAMP (10-50 mum) enhanced CACNA1H mRNA and Ca(v)3.2 current, whereas nonhydrolyzable Sp-8CPT-cAMP failed to increase either Ca(v)3.2 current or mRNA. Metabolites of 8CPT-cAMP, including 8CPT-adenosine and 8CPT-adenine, increased Ca(v)3.2 current and mRNA with a potency and effectiveness similar to the parent compound. The Epac activator 8CPT-2'-O-methyl-cAMP and its metabolites 8CPT-2'-OMe-5'-AMP and 8CPT-2'-O-methyl-adenosine increased CACNA1H mRNA and Ca(v)3.2 current; Sp-8CPT-2'-O-methyl-cAMP increased neither Ca(v)3.2 current nor mRNA. These results reveal an interesting dichotomy between ACTH and cAMP with regard to regulation of CACNA1H mRNA and Ca(2+) current. Specifically, ACTH induces expression of CACNA1H mRNA and Ca(v)3.2 current in AZF cells by mechanisms that depend at most only partly on cAMP. In contrast, cAMP enhances expression of CACNA1H mRNA but not the corresponding Ca(2+) current. Surprisingly, chlorophenylthio-cAMP analogs stimulate the expression of Ca(v)3.2 current indirectly through metabolites. ACTH and the metabolites may induce Ca(v)3.2 expression by the same, unidentified mechanism.
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Affiliation(s)
- Haiyan Liu
- Department of Neuroscience, The Ohio State University, College of Medicine and Public Health, Columbus, Ohio 43210-1239, USA
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Hayashi C, Iino K, Oki Y, Matsushita F, Yamashita M, Yogo K, Sasaki S, Kumada T, Nakamura H. Possible contribution of 2-aminoethoxydiphenyl-borate-sensitive Ca2+ mobilization to adrenocorticotropin-induced glucocorticoid synthesis in rat adrenocortical cells. Endocr J 2010; 57:109-17. [PMID: 19851032 DOI: 10.1507/endocrj.k09e-138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Cytoplasmic calcium ([Ca(2+)](i)) provided through voltage-dependent Ca(2+) channels (VDCC) plays an important role in adrenocorticotropin (ACTH)-induced steroidogenesis in adrenocortical cells. To identify alternative mechanisms for [Ca(2+)](i) supply, we investigated the 2-aminoethoxydiphenyl borate (2APB)-sensitive pathway as one of the possible signaling pathways involved in [Ca(2+)](i) supply for ACTH-induced steroidogenesis. In monolayers of cultured rat adrenal fasciculate and reticularis cells, ACTH at 10(-11) M stimulated corticosterone synthesis without increasing intracellular cAMP, and corticosterone synthesis was decreased by 10 microM 2APB by 51.8% (6.71 +/- 0.97 vs. 3.23 +/- 0.05 ng/mL/4 hours; p<0.05). Furthermore, 2APB significantly decreased the 10(-11) M ACTH-stimulated [Ca(2+)](i). ACTH increased the intracellular inositol-1,4,5-trisphosphate (IP3) content with a peak at 10(-13) M ACTH, which illustrates the possibility that ACTH activates IP3/diacylglycerol- dependent protein kinase C signal transduction. However, the difference in ACTH concentrations between that responsible for the IP3 increase and steroidogenesis without elevated cAMP, suggest a hypothesis that IP3 is not required for steroidogenesis, but does involve an unknown messenger, which stimulates the release of Ca(2+) from the ER or the subsequent store-operated Ca(2+) entry (SOCE). The pregnenolone concentration in the culture medium was increased by ACTH, which was significantly suppressed by 2APB, showing that the 2APB-sensitive Ca(2+) supply affects cholesterol transport into the mitochondrial membrane via steroidogenic acute regulatory protein. Therefore, the SOCE may contribute to ACTH-induced steroidogenesis in the mitochondrial region. In conclusion, the [Ca(2+)](i) used for steroidogenesis may be derived from a 2APB-sensitive pathway and via VDCCs, particularly at physiological concentrations of ACTH. We suggest that ACTH receptors activate steroidogenesis via inositol triphosphate, or an unknown downstream messenger, which could be inhibited by 2APB.
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Affiliation(s)
- Chiga Hayashi
- Second Division, Department of Medicine, Hamamatsu University School of Medicine,1-20-1 Handayama, Higashi-ku, Hamamatsu, Japan
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Qiao S, Okret S, Jondal M. Thymocyte-synthesized glucocorticoids play a role in thymocyte homeostasis and are down-regulated by adrenocorticotropic hormone. Endocrinology 2009; 150:4163-9. [PMID: 19406942 DOI: 10.1210/en.2009-0195] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thymocytes from adult mice synthesize glucocorticoids (GCs), and some data indicate a role for this hormone production in thymic homeostasis. Here we present further support for this view by showing that the dramatic increase in thymocyte number seen after adrenalectomy (ADX) does not correlate with the decrease in systemic GCs but rather with an ACTH-mediated down-regulation of GC synthesis in thymocytes. High ACTH concentrations caused by ADX in wild-type mice down-regulated CYP11B1 mRNA expression, encoding the last enzyme required for corticosterone synthesis and as a consequence reduced GC synthesis in thymocytes. This was not seen in IL-1beta/IL-18 double-knockout mice unable to respond to ADX with high ACTH levels. However, if ADX IL-1beta/IL-18 double-knockout mice were treated with ACTH, this led to a down-regulation of CYP11B1 and GC synthesis in thymocytes. In addition, in vivo treatment of mice with the CYP11B1 antagonist metyrapone, without affecting the systemic corticosterone level, increased thymocyte numbers and in vitro treatment of isolated thymocytes prevented thymocyte loss. Furthermore, in vitro experiments showed that both ACTH and its receptor-induced second-messenger molecule cAMP down-regulated mRNA expression of critical enzymes in GC steroidogenesis and GC synthesis in thymocytes. We conclude that thymocyte-produced GCs are important for the homeostasis of adult mouse thymocytes and that high ACTH level, in contrast to stimulating GC synthesis in the adrenal glands, has the opposite effect in thymocytes.
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Affiliation(s)
- Shengjun Qiao
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
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Enyeart JA, Liu H, Enyeart JJ. Curcumin inhibits ACTH- and angiotensin II-stimulated cortisol secretion and Ca(v)3.2 current. JOURNAL OF NATURAL PRODUCTS 2009; 72:1533-7. [PMID: 19653644 PMCID: PMC2853174 DOI: 10.1021/np900227x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Adrenocorticotropic hormone and angiotensin II stimulate cortisol secretion from bovine adrenal zona fasciculata cells by the activation of adenylate cyclase and phospholipase C-coupled receptors. Curcumin (1- 20 muM), a compound found in the spice turmeric, inhibited cortisol secretion stimulated by ACTH, AngII, and 8CPT-cAMP. Curcumin also suppressed ACTH-stimulated increases in mRNAs coding for steroid acute regulatory protein and CYP11a1 steroid hydroxylase. In whole cell patch clamp recordings from AZF cells, curcumin at slightly higher concentrations also inhibited Ca(v)3.2 current. These results identify curcumin as an effective inhibitor of ACTH- and AngII-stimulated cortisol secretion. The inhibition of Ca(v)3.2 current by curcumin may contribute to its suppression of secretion.
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Affiliation(s)
- Judith A. Enyeart
- Department of Neuroscience, The Ohio State University College of Medicine and Public Health, Columbus, Ohio 43210-1239
| | - Haiyan Liu
- Department of Neuroscience, The Ohio State University College of Medicine and Public Health, Columbus, Ohio 43210-1239
| | - John J. Enyeart
- Department of Neuroscience, The Ohio State University College of Medicine and Public Health, Columbus, Ohio 43210-1239
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Current World Literature. Curr Opin Nephrol Hypertens 2009; 18:91-3. [DOI: 10.1097/mnh.0b013e32831fd875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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