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Faiad W, Soukkarieh C, Hanano A. 2,3,7,8-tetrachlorodibenzo-p-dioxin induces multigenerational testicular toxicity and biosynthetic disorder of testosterone in BALB/C mice: Transcriptional, histopathological and hormonal determinants. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 263:115233. [PMID: 37421896 DOI: 10.1016/j.ecoenv.2023.115233] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Revised: 06/30/2023] [Accepted: 07/04/2023] [Indexed: 07/10/2023]
Abstract
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a potent environmental contaminant, is an endocrine disrupter with a proven reproductive toxicity in mammals. However, its effects on male fertility across generations are still elusive. The current work evaluates the toxicity of dioxin on male reproductive system in two separate groups of BALB/C mice; a group of pubertal males directly exposed to TCDD (referred to as DEmG), and a group of indirectly exposed males (referred to as IDEmG) comprises of F1, F2 and F3 males born from TCDD-exposed pregnant females. Both groups were exposed to 25 μg TCDD/kg body weight for a week. Our data show that males of TCDD-DEmG exhibited significant alterations in the expression of certain genes involved in the detoxification of TCDD and the biosynthesis of testosterone. This was accompanied with testicular pathological symptoms, including a sloughing in the germinal epithelium and a congestion of blood vessels in interstitial tissue with the presence of multinuclear cells into seminiferous tubule, with a 4-fold decline in the level of serum testosterone and reduced sperm count. Otherwise, the male reproductive toxicity across F1, F2 and F3 generations from TCDD-IDEmG was mainly characterized by: i) a reduce in body and testis weight. ii) a decrease in gene expression of steriodogenesis enzyme, e.g., AhR, CYP1A1, CYP11A1, COX1, COX2, LOX5 and LOX12. iii) a remarked and similar testicular histopathology that found for DEmG, iv) a serious decline in serum testosterone. v) a decreased male-to-female ratio. vi) a low sperm count with increasing abnormalities. Thus, pubertal or maternal exposure to TCDD provokes multigenerational male reproductive toxicity in mice, ultimately affecting the spermatogenesis and suggesting that the hormonal alternation and sperm abnormality are the most marked effects of the indirect exposure of mammalian male to TCDD.
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Affiliation(s)
- Walaa Faiad
- Department of Animal Biology, Faculty of Sciences, University of Damascus, Damascus, Syria
| | - Chadi Soukkarieh
- Department of Animal Biology, Faculty of Sciences, University of Damascus, Damascus, Syria
| | - Abdulsamie Hanano
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), Damascus, Syria.
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2
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Mori Sequeiros Garcia MM, Paz C, Castillo AF, Benzo Y, Belluno MA, Balcázar Martínez A, Maloberti PM, Cornejo Maciel F, Poderoso C. New insights into signal transduction pathways in adrenal steroidogenesis: role of mitochondrial fusion, lipid mediators, and MAPK phosphatases. Front Endocrinol (Lausanne) 2023; 14:1175677. [PMID: 37223023 PMCID: PMC10200866 DOI: 10.3389/fendo.2023.1175677] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/17/2023] [Indexed: 05/25/2023] Open
Abstract
Hormone-receptor signal transduction has been extensively studied in adrenal gland. Zona glomerulosa and fasciculata cells are responsible for glucocorticoid and mineralocorticoid synthesis by adrenocorticotropin (ACTH) and angiotensin II (Ang II) stimulation, respectively. Since the rate-limiting step in steroidogenesis occurs in the mitochondria, these organelles are key players in the process. The maintenance of functional mitochondria depends on mitochondrial dynamics, which involves at least two opposite events, i.e., mitochondrial fusion and fission. This review presents state-of-the-art data on the role of mitochondrial fusion proteins, such as mitofusin 2 (Mfn2) and optic atrophy 1 (OPA1), in Ang II-stimulated steroidogenesis in adrenocortical cells. Both proteins are upregulated by Ang II, and Mfn2 is strictly necessary for adrenal steroid synthesis. The signaling cascades of steroidogenic hormones involve an increase in several lipidic metabolites such as arachidonic acid (AA). In turn, AA metabolization renders several eicosanoids released to the extracellular medium able to bind membrane receptors. This report discusses OXER1, an oxoeicosanoid receptor which has recently arisen as a novel participant in adrenocortical hormone-stimulated steroidogenesis through its activation by AA-derived 5-oxo-ETE. This work also intends to broaden knowledge of phospho/dephosphorylation relevance in adrenocortical cells, particularly MAP kinase phosphatases (MKPs) role in steroidogenesis. At least three MKPs participate in steroid production and processes such as the cellular cycle, either directly or by means of MAP kinase regulation. To sum up, this review discusses the emerging role of mitochondrial fusion proteins, OXER1 and MKPs in the regulation of steroid synthesis in adrenal cortex cells.
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Affiliation(s)
- María Mercedes Mori Sequeiros Garcia
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Cristina Paz
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Ana Fernanda Castillo
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Yanina Benzo
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Matías A. Belluno
- CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Ariana Balcázar Martínez
- CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Paula Mariana Maloberti
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Fabiana Cornejo Maciel
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
| | - Cecilia Poderoso
- Universidad de Buenos Aires, Facultad de Medicina, Departamento de Bioquímica Humana, Buenos Aires, Argentina
- CONICET-Universidad de Buenos Aires, Instituto de Investigaciones Biomédicas (INBIOMED), Buenos Aires, Argentina
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3
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Hoxha M, Barbonetti A, Zappacosta B. Arachidonic Acid Pathways and Male Fertility: A Systematic Review. Int J Mol Sci 2023; 24:ijms24098207. [PMID: 37175913 PMCID: PMC10178949 DOI: 10.3390/ijms24098207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/23/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
Arachidonic acid (AA) is a polyunsaturated fatty acid that is involved in male fertility. Human seminal fluid contains different prostaglandins: PGE (PGE1 and PGE2), PGF2α, and their specific 19-hydroxy derivatives, 18,19-dehydro derivatives of PGE1 and PGE2. The objective of this study is to synthesize the available literature of in vivo animal studies and human clinical trials on the association between the AA pathway and male fertility. PGE is significantly decreased in the semen of infertile men, suggesting the potential for exploitation of PGE agonists to improve male fertility. Indeed, ibuprofen can affect male fertility by promoting alterations in sperm function and standard semen parameters. The results showed that targeting the AA pathways could be an attractive strategy for the treatment of male fertility.
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Affiliation(s)
- Malvina Hoxha
- Department for Chemical-Toxicological and Pharmacological Evaluation of Drugs, Faculty of Pharmacy, Catholic University Our Lady of Good Counsel, 1000 Tirana, Albania
| | - Arcangelo Barbonetti
- Andrology Unit, Department of Life, Health and Environmental Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Bruno Zappacosta
- Department for Chemical-Toxicological and Pharmacological Evaluation of Drugs, Faculty of Pharmacy, Catholic University Our Lady of Good Counsel, 1000 Tirana, Albania
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Neuman I, Cooke M, Lemiña NA, Kazanietz MG, Cornejo Maciel F. 5-oxo-ETE activates migration of H295R adrenocortical cells via MAPK and PKC pathways. Prostaglandins Other Lipid Mediat 2019; 144:106346. [PMID: 31301403 DOI: 10.1016/j.prostaglandins.2019.106346] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 06/06/2019] [Accepted: 06/19/2019] [Indexed: 01/08/2023]
Abstract
The OXE receptor is a GPCR activated by eicosanoids produced by the action of 5-lipoxygenase. We previously found that this membrane receptor participates in the regulation of cAMP-dependent and -independent steroidogenesis in human H295R adrenocortical carcinoma cells. In this study we analyzed the effects of the OXE receptor physiological activator 5-oxo-ETE on the growth and migration of H259R cells. While 5-oxo-ETE did not affect the growth of H295R cells, overexpression of OXE receptor caused an increase in cell proliferation, which was further increased by 5-oxo-ETE and blocked by 5-lipoxygenase inhibition. 5-oxo-ETE increased the migratory capacity of H295R cells in wound healing assays, but it did not induce the production of metalloproteases MMP-1, MMP-2, MMP-9 and MMP-10. The pro-migratory effect of 5-oxo-ETE was reduced by pharmacological inhibition of the MEK/ERK1/2, p38 and PKC pathways. 5-oxo-ETE caused significant activation of ERK and p38. ERK activation by the eicosanoid was reduced by the "pan" PKC inhibitor GF109203X but not by the classical PKC inhibitor Gö6976, suggesting the involvement of novel PKCs in this effect. Although H295R cells display detectable phosphorylation of Ser299 in PKCδ, a readout for the activation of this novel PKC, treatment with 5-oxo-ETE per se was unable to induce additional PKCδ activation. Our results revealed signaling effectors activated by 5-oxo-ETE in H295R cells and may have significant implications for our understanding of OXE receptor in adrenocortical cell pathophysiology.
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Affiliation(s)
- Isabel Neuman
- Departamento de Bioquímica Humana, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina; INBIOMED, Instituto de Investigaciones Biomédicas, UBA, CONICET, Buenos Aires, Argentina
| | - Mariana Cooke
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Nicolás Agustín Lemiña
- INBIOMED, Instituto de Investigaciones Biomédicas, UBA, CONICET, Buenos Aires, Argentina
| | - Marcelo G Kazanietz
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Fabiana Cornejo Maciel
- Departamento de Bioquímica Humana, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina; INBIOMED, Instituto de Investigaciones Biomédicas, UBA, CONICET, Buenos Aires, Argentina.
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Lai KP, Lee JCY, Wan HT, Li JW, Wong AYM, Chan TF, Oger C, Galano JM, Durand T, Leung KS, Leung CC, Li R, Wong CKC. Effects of in Utero PFOS Exposure on Transcriptome, Lipidome, and Function of Mouse Testis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:8782-8794. [PMID: 28654245 DOI: 10.1021/acs.est.7b02102] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Transcriptomic and LC-MS/MS-based targeted lipidomic analyses were conducted to identify the effects of in utero PFOS exposure on neonatal testes and its relation to testicular dysfunction in adult offspring. Pregnant mice were orally administered 0.3 and 3 μg PFOS/g body weight until term. Neonatal testes (P1) were collected for the detection of PFOS, and were subjected to omics study. Integrated pathway analyses using DAVID, KEGG, and IPA underlined the effects of PFOS exposure on lipid metabolism, oxidative stress and cell junction signaling in testes. LC-MS/MS analysis showed that the levels of adrenic acid and docosahexaenoic acid (DHA) in testes were significantly reduced in the PFOS treatment groups. A significant linear decreasing trend in eicosapentaenoic acid and DHA with PFOS concentrations was observed. Moreover, LOX-mediated 5-hydroxyeicosatetraenoic acids (HETE) and 15-HETE from arachidonic acid in the testes were significantly elevated and a linear increasing trend of 15-HETE concentrations was detected with doses of PFOS. The perturbations of lipid mediators suggested that PFOS has potential negative impacts on testicular functions. Postnatal analysis of male offspring at P63 showed significant reductions in serum testosterone and epididymal sperm count. This study sheds light into the as yet unrevealed action of PFOS on lipid mediators in affecting testicular functions.
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Affiliation(s)
- Keng Po Lai
- Department of Biology and Chemistry, City University of Hong Kong , Hong Kong
| | | | - Hin Ting Wan
- Partner State Key Laboratory of Environmental and Biological Analysis, Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University , Hong Kong
| | - Jing Woei Li
- School of Life Sciences, The Chinese University of Hong Kong , Hong Kong
| | - Aman Yi-Man Wong
- Partner State Key Laboratory of Environmental and Biological Analysis, Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University , Hong Kong
| | - Ting Fung Chan
- School of Life Sciences, The Chinese University of Hong Kong , Hong Kong
| | - Camille Oger
- Institut des Biomolécules Max Mousseron, UMR 5247 CNRS, ENSCM, Université de Montpellier , Montpellier, France
| | - Jean-Marie Galano
- Institut des Biomolécules Max Mousseron, UMR 5247 CNRS, ENSCM, Université de Montpellier , Montpellier, France
| | - Thierry Durand
- Institut des Biomolécules Max Mousseron, UMR 5247 CNRS, ENSCM, Université de Montpellier , Montpellier, France
| | - Kin Sum Leung
- School of Biological Sciences, The University of Hong Kong , Hong Kong
| | - Cherry C Leung
- Partner State Key Laboratory of Environmental and Biological Analysis, Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University , Hong Kong
| | - Rong Li
- Partner State Key Laboratory of Environmental and Biological Analysis, Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University , Hong Kong
| | - Chris Kong-Chu Wong
- Partner State Key Laboratory of Environmental and Biological Analysis, Croucher Institute for Environmental Sciences, Department of Biology, Hong Kong Baptist University , Hong Kong
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6
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Ding H, Zhang Y, Liu L, Yuan H, Qu J, Shen R. Activation of Peroxisome Proliferator Activator Receptor Delta in Mouse Impacts Lipid Composition and Placental Development at Early Stage of Gestation1. Biol Reprod 2014; 91:57. [DOI: 10.1095/biolreprod.113.116772] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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7
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Group IVA phospholipase A2 regulates testosterone biosynthesis by murine Leydig cells and is required for timely sexual maturation. Biochem J 2011; 439:403-11. [PMID: 21762109 DOI: 10.1042/bj20102167] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In the present paper, we report that PLA2G4A (Group IVA phospholipase A2) is important in the development and function of rodent testes. Interstitial cells of rat testes had high PLA2 (phospholipase A2) activity that was very sensitive to the PLA2G4A-preferential inhibitor AACOCF3 (arachidonyl trifluoromethyl ketone). PLA2G4A protein was expressed primarily in the interstitial cells of wild-type mouse testes throughout maturation. Although Pla2g4a knockout (Pla2g4a-/-) male mice are fertile, their sexual maturation was delayed, as indicated by cauda epididymal sperm count and seminal vesicle development. Delayed function of Pla2g4a-/- mice testes was associated with histological abnormalities including disorganized architecture, swollen appearance and fewer interstitial cells. Basal secretion of testosterone was attenuated significantly and steroidogenic response to hCG (human chorionic gonadotropin) treatment was reduced in Pla2g4a-/- mice compared with their Pla2g4a+/+ littermates during the sexual maturation period. Chemical inhibition of PLA2G4A activity by AACOCF3 or pyrrophenone significantly reduced hCG-stimulated testosterone production in cultured rat interstitial cells. AACOCF3 inhibited forskolin- and cAMP analogue-stimulated testosterone production. These results provide the first evidence that PLA2G4A plays a role in male testes physiology and development. These results may have implications for the potential clinical use of PLA2G4A inhibitors.
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8
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Balaji T, Ramanathan M, Padmanabhan Menon V. Localization of cyclooxygenase-2 in mice testis and assessment of its possible role through suppressing its expression using nimesulide: a preferential cyclooxygenase-2 inhibitor. Prostaglandins Leukot Essent Fatty Acids 2007; 76:341-8. [PMID: 17624748 DOI: 10.1016/j.plefa.2007.04.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 03/04/2007] [Accepted: 04/25/2007] [Indexed: 01/22/2023]
Abstract
Present generation non-steroidal anti-inflammatory drugs (NSAID) are potent inhibitors of the enzyme cyclooxygenase-2 (COX-2). Even though they exhibit reduced incidence of gastrotoxicity, severe nephrotoxicity and other side effects have been widely reported with respect to usage of these drugs. Since COX-2 levels are not only upregulated by inflammation but also by other stimuli such as cytokines, growth factors, mitogens and steroid hormones, we investigated the localization of COX-2 and activity of both COX-1 and COX-2 in mice testis. To correlate the localization of COX-2 with its function we suppressed COX-2 expression with the aid of nimesulide a preferential COX-2 inhibitor. We found COX-2 was constitutively expressed in the Leydig cells of mice testis suggesting a role on testosterone synthesis. Suppression of COX-2 resulted in increased concentration of most of polyunsaturated fatty acids especially arachidonic acid (AA). Prostaglandin (PG) levels which showed an initial decline during nimesulide treatment had a reversible effect during prolonged treatment. These findings state that cyclooxygenase is constitutively expressed in mice testis and continuous inhibition of COX-2 interferes in maturation of sperm.
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Affiliation(s)
- Thotakura Balaji
- Department of Anatomy, Faculty of Medicine, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India
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Maloberti P, Cornejo Maciel F, Castillo AF, Castilla R, Duarte A, Toledo MF, Meuli F, Mele P, Paz C, Podestá EJ. Enzymes involved in arachidonic acid release in adrenal and Leydig cells. Mol Cell Endocrinol 2007; 265-266:113-20. [PMID: 17207922 DOI: 10.1016/j.mce.2006.12.026] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Stimulation of receptors and subsequent signal transduction results in the activation of arachidonic acid (AA) release. Once AA is released from phospholipids or others esters, it may be metabolized via the cycloxygenase or the lipoxygenase pathways. How the cells drive AA to these pathways is not elucidated yet. It is reasonable to speculate that each pathway will have different sources of free AA triggered by different signal transduction pathways. Several reports have shown that AA and its lipoxygenase-catalyzed metabolites play essential roles in the regulation of steroidogenesis by influencing cholesterol transport from the outer to the inner mitochondrial membrane, the rate-limiting step in steroid hormone biosynthesis. Signals that stimulate steroidogenesis also cause the release of AA from phospholipids or other esters by mechanisms that are not fully understood. This review focuses on the enzymes of AA release that impact on steroidogenesis.
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Affiliation(s)
- P Maloberti
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Paraguay 2155, 5 degrees (C1121ABG), Buenos Aires, Argentina
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Kurusu S, Ohkawa M, Kawaminami M. Effects of arachidonate metabolism inhibitors on basal and human chorionic gonadotropin-stimulated progesterone secretion by rat corpus luteum cells in vitro. Prostaglandins Other Lipid Mediat 2006; 83:139-45. [PMID: 17259080 DOI: 10.1016/j.prostaglandins.2006.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Revised: 10/27/2006] [Accepted: 10/31/2006] [Indexed: 10/23/2022]
Abstract
Arachidonic acid (AA) and its metabolites mediate many physiological processes including reproduction and endocrinology. The current study investigated effects of several inhibitors of AA cascade on steroidogenesis by rat corpus luteum cells in vitro. Dispersed luteal cells prepared from rat corpus luteum on day 6 of pseudopregnancy secreted progesterone (P4) in time-dependent and human chorinonic gonadotropin (hCG)-dependent fashion. Arachidonyl trifluoromethyl ketone, a preferential inhibitor of the type IVA phospholipase A(2) (PLA(2)-IVA), stimulated basal P4 secretion and had no influence on hCG-stimulated steroidogenesis. A novel and more specific inhibitor pyrrophenone inhibited hCG-induced P4 secretion. A cyclooxygenase inhibitor indomethacin did not affect basal secretion but inhibited hCG-stimulated secretion. Nordihydroguaiaretic acid tended to decrease basal P4 secretion and completely inhibited hCG-stimulated secretion. Obtained results suggest that AA metabolic cascade, which is triggered at least in part by PLA(2)-IVA activity, is potentially implicated in hCG-stimulated P4 secretory response in the rat corpus luteum.
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Affiliation(s)
- Shiro Kurusu
- Laboratory of Physiology, Kitasato University School of Veterinary Medicine and Animal Sciences, Towada, Aomori 034-8628, Japan.
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Castilla R, Maloberti P, Castillo F, Duarte A, Cano F, Cornejo Maciel F, Neuman I, Mendez CF, Paz C, Podestá EJ. Arachidonic acid regulation of steroid synthesis: new partners in the signaling pathway of steroidogenic hormones. Endocr Res 2004; 30:599-606. [PMID: 15666797 DOI: 10.1081/erc-200043765] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Although the role of arachidonic acid (AA) in trophic hormone-stimulated steroid production in various steroidogenic cells is well documented, the mechanism responsible for AA release remains unknown. We have previously shown evidence of an alternative pathway of AA generation in steroidogenic tissues. Our results are consistent with the hypothesis that, in steroidogenic cells, AA is released by the action of a mitochondrial acyl-CoA thioesterase (MTE-I). We have shown that recombinant MTE-I hydrolyses arachidonoyl-CoA to release free AA. An acyl-CoA synthetase specific for AA, acyl-CoA synthetase 4, has also been described in steroidogenic tissues. In the present study we investigate the new concept in the regulation of intracellular levels of AA, in which trophic hormones can release AA by mechanisms different from the classical PLA2-mediated pathway. Inhibition of ACS4 and MTE-I activity by triacsin C and NDGA, respectively results in a reduction of StAR mRNA and protein abundance. When both inhibitors are added together there is a synergistic effect in the inhibition of StAR mRNA, StAR protein levels and ACTH-stimulated steroid synthesis. The inhibition of steroidogenesis produced by the NDGA and triacsin C can be overcome by the addition of exogenous AA. In summary, results shown here demonstrate a critical role of the acyl-CoA synthetase and the acyl-CoA thioesterase in the regulation of AA release, StAR induction, and steroidogenesis. This further suggests a new concept in the regulation of intracellular distribution of AA through a mechanism different from the classical PLA2-mediated pathway that involves a hormone-induced acyl-CoA synthetase and a hormone-regulated acyl-CoA thioesterase.
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Affiliation(s)
- R Castilla
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
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12
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Castillo F, Cano F, Maloberti P, Castilla R, Neuman I, Poderoso C, Paz C, Podestá EJ, Cornejo Maciel F. Tyrosine phosphates act on steroidogenesis through the activation of arachidonic acid release. Endocr Res 2004; 30:623-7. [PMID: 15666802 DOI: 10.1081/erc-200043795] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The ACTH signaling pathway includes both PKA activation as well as PKA-dependent tyrosine phosphatase activation. In addition, the action of this hormone also includes the regulation of the intracellular levels of arachidonic acid (AA) by the concerted action of two enzymes: an acylCoA-thioesterase and an acyl-CoA-synthetase (ACS4). This work describes the production and characterization of a specific ACS4 antibody, which was used to analyze the effect of ACTH on ACS4 protein level in Y1 adrenocortical cells and the putative relationship between tyrosine phosphatases and ACS4. The antiserum was obtained from rabbits immunized with the recombinant ACS4. This immunogen was produced in bacteria and eluted from an acrylamide gel after SDS-PAGE separation of a partially purified bacteria lysate. When used in Western blot analysis, the antibody obtained specifically recognized only one protein of the molecular mass corresponding to ACS4, in Y1 cells and in several rat tissues. Using the antibody described here, we analyzed the effect of ACTH stimulation on ACS4 protein level. The hormone produced an increase of this acyl-CoA synthetase in Y1 adrenocortical cells. Moreover, this effect was mimicked by cAMP and partially reduced by a tyrosine phosphatase inhibitor. We propose that ACTH regulates ACS4 protein levels through a PKA-dependent mechanism that could involve also PTP activity.
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Affiliation(s)
- Fernanda Castillo
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
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Lozano RC, Maloberti P, Mendez CF, Paz C, Podestá EJ. ACTH regulation of mitochondrial acyl-CoA thioesterase activity in Y1 adrenocortical tumour cells. Endocr Res 2002; 28:331-7. [PMID: 12530634 DOI: 10.1081/erc-120016805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We have previously purified and cloned a phosphoprotein, Arachidonic acid-Related Thioesterase Involved in Steroidogenesis (ARTISt), involved in steroid synthesis through Arachidonic Acid (AA) release. Arachidonic acid-related thioesterase involved in steroidogenesis resulted to be a member of a new family of acyl-CoA thioesterases. The protein was identified by its biocapacity to increase mitochondrial steroidogenesis in a cell free bioassay. In the present study we measure the activity of ARTISt using arachidonoyl-CoA (AA-CoA) as substrate. We demonstrate that ACTH significantly stimulates endogenous mitochondrial thioesterase activity as early as 5 min after ACTH stimulation of Y1 cells. Nordihydroguaiaretic acid (NDGA), an inhibitor of AA release known to affect steroidogenesis, affects the in vitro activity of recombinant ARTISt and also the endogenous mitochondrial acyl-CoA thioesterases. ACTH activation of the enzyme protected ARTISt to the inhibitory effect of NDGA. These results show that an enzyme that release AA from AA-CoA can be regulated in intact cells by steroidogenic hormones.
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Maloberti P, Lozano RC, Mele PG, Cano F, Colonna C, Mendez CF, Paz C, Podestá EJ. Concerted regulation of free arachidonic acid and hormone-induced steroid synthesis by acyl-CoA thioesterases and acyl-CoA synthetases in adrenal cells. EUROPEAN JOURNAL OF BIOCHEMISTRY 2002; 269:5599-607. [PMID: 12423359 DOI: 10.1046/j.1432-1033.2002.03267.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Although the role of arachidonic acid (AA) in the regulation of steroidogenesis is well documented, the mechanism for AA release is not clear. Therefore, the aim of this study was to characterize the role of an acyl-CoA thioesterase (ARTISt) and an acyl-CoA synthetase as members of an alternative pathway in the regulation of the intracellular levels of AA in steroidogenesis. Purified recombinant ARTISt releases AA from arachidonoyl-CoA (AA-CoA) with a Km of 2 micro m. Antibodies raised against recombinant acyl-CoA thioesterase recognize the endogenous protein in both adrenal tissue and Y1 adrenal tumor cells by immunohistochemistry and immunocytochemistry and Western blot. Stimulation of Y1 cells with ACTH significantly stimulated endogenous mitochondrial thioesterases activity (1.8-fold). Nordihydroguaiaretic acid (NDGA), an inhibitor of AA release known to affect steroidogenesis, affects the in vitro activity of recombinant ARTISt and also the endogenous mitochondrial acyl-CoA thioesterases. ACTH-stimulated steroid synthesis in Y1 cells was significantly inhibited by a synergistic effect of NDGA and triacsin C an inhibitor of the AA-CoA synthetase. The apparent IC50 for NDGA was reduced from 50 micro m to 25, 7.5 and 4.5 micro m in the presence of 0.1, 0.5 and 2 micro m triacsin C, respectively. Our results strongly support the existence of a new pathway of AA release that operates in the regulation of steroid synthesis in adrenal cells.
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Affiliation(s)
- Paula Maloberti
- Department of Biochemistry, School of Medicine, University of Buenos Aires
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15
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Walch L, Morris PL. Cyclooxygenase 2 pathway mediates IL-1beta regulation of IL-1alpha, -1beta, and IL-6 mRNA levels in Leydig cell progenitors. Endocrinology 2002; 143:3276-83. [PMID: 12193539 DOI: 10.1210/en.2002-220410] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prostanoids are arachidonic acid (AA) metabolites derived from the cyclooxygenase (COX1 and COX2 isozymes) pathway and are involved in signal transduction pathways activated by distinct ILs. Although COX1 is the constitutive isoform of COX, IL-1beta is a potent inducer of COX2 expression in distinct cell types. This study was designed to determine whether cyclooxygenases could mediate endogenous cytokine regulation in rat progenitor Leydig cells. COX and IL (IL-1alpha, IL-1beta, and IL-6) mRNAs were measured by PCR and real-time PCR analyses, respectively. COX function was assessed using COX activity inhibitors: indomethacin (INDO; COX1 and COX2 inhibitor) and NS-398 (COX2 selective inhibitor). Our data indicate that endogenous progenitor COX1 mRNA levels are low and are not regulated by IL-1beta. In contrast, COX2 mRNA is induced by IL-1beta at 6, 9, and 24 h. IL-1beta induction of IL mRNAs was in part significantly impaired in the presence of INDO or NS-398. Among the prostanoids tested, prostaglandin E(2) (PGE(2)), PGF(2alpha), and carbaprostacyclin reversed the INDO inhibition of IL production. PGs alone have no (IL-1alpha and IL-1beta) or a modest (IL-6) effect on IL mRNA levels. PGE(2), PGF(2alpha), and PGI(2) measurements show that IL-1beta treatment significantly increases progenitor Leydig cell production of these PGs. Taken together, our data demonstrate that this COX2 cascade is a regulator of cytokines in Leydig progenitors.
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Affiliation(s)
- Laurence Walch
- Population Council and The Rockefeller University, New York, New York 10021, USA
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16
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Conte D, Romanelli F, Fillo S, Guidetti L, Isidori A, Franceschi F, Latini M, di Luigi L. Aspirin inhibits androgen response to chorionic gonadotropin in humans. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:E1032-7. [PMID: 10600792 DOI: 10.1152/ajpendo.1999.277.6.e1032] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Eicosanoids play an important role in the regulation of the hypothalamic-pituitary axis; less clear is their role in testicular steroidogenesis. To evaluate the involvement of cyclooxygenase metabolites, such as prostaglandins, in the regulation of human testicular steroidogenesis, we examined the effects of a prostaglandin-blocker, aspirin, on plasma testosterone, pregnenolone, progesterone, 17OH-progesterone, androstenedione, dehydroepiandrosterone, and 17beta-estradiol response to human chorionic gonadotropin (hCG) in normal male volunteers in a placebo-controlled, single-blinded study. To test the efficacy of aspirin, seminal prostaglandin E(2) levels were also determined. hCG stimulation increased peripheral levels of testosterone, 17OH-progesterone, androstenedione, dehydroepiandrosterone, and 17beta-estradiol, without affecting circulating pregnenolone and progesterone values. Aspirin significantly lowered seminal prostaglandin E(2) levels, whereas it did not modify steroid concentrations not exposed to exogenous hCG. Moreover, the drug significantly reduced the response of testosterone, 17OH-progesterone, androstenedione, and dehydroepiandrosterone to hCG, as assessed by the mean integrated area under the curve, whereas it did not influence 17beta-estradiol response. In conclusion, aspirin treatment inhibits androgen response to chorionic gonadotropin stimulation in normal humans. The action of aspirin is probably mediated via an effective arachidonate cyclooxygenase block.
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Affiliation(s)
- D Conte
- Division of Andrology, Department of Medical Pathophysiology, University "La Sapienza," 00161 Rome, Italy.
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17
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Abayasekara DR, Wathes DC. Effects of altering dietary fatty acid composition on prostaglandin synthesis and fertility. Prostaglandins Leukot Essent Fatty Acids 1999; 61:275-87. [PMID: 10670689 DOI: 10.1054/plef.1999.0101] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Several studies over the past 20 years have demonstrated that subjects on diets composed of substances with high levels of n-3 polyunsaturated fatty acids (PUFAs) (e.g. fish) have a decreased incidence of heart disease. On this basis, a recent report from the Department of Health has advised UK consumers to decrease the proportion of saturated as opposed to unsaturated fats in their diet and to increase the ratio of n-3 to n-6 PUFAs. This could be achieved by altering the amounts of these constituents in milk and meat. n-3 Fatty acids can most easily be added to animal feed as either fish oil or linseed oil and can be increased in the blood and milk of ruminants following protection to avoid hydrogenation in the rumen. In western countries the ratio of consumption of n-6 to n-3 PUFAs is greater than 10 and current evidence tends to suggest that a ratio nearer 5 would be more desirable and compatible with cardiovascular well being. As fertility in the UK dairy herd is already poor, it is important to establish whether alterations in dietary n-3 and n-6 PUFAs affects herd fertility before widespread changes in animal diets are recommended. Therefore, this review considers the role played by PUFAs and eicosanoids in fertility, with particular reference to the implications for farm livestock production. The evidence reviewed shows that alteration of the concentration and ratio of n-6 and n-3 PUFAs in feeds can influence prostaglandin synthesis/metabolism in a number of mammalian systems. The changed patterns of prostaglandin synthesis can as a consequence, affect the diverse functions (e.g. hormone secretion) that are normally mediated via prostaglandins. Similarly, changes in prostaglandin synthesis effected through manipulation of PUFAs has a major bearing on fertility (as PGs affect many reproductive parameters, e.g. ovulation). Several studies in cattle and other mammals, show that feeding or infusing different types of fat with varying PUFA content to females can alter: the number and size of ovarian follicles, the ovulation rate, progesterone production by the corpus luteum, the timing of luteolysis and gestational length. In the male most recent work has focussed on sperm production and experiments in fowl have demonstrated clear effects of dietary PUFAs on both the sperm membrane phospholipid composition and on fertilizing ability.
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Affiliation(s)
- D R Abayasekara
- Reproduction and Development Group, Department of Veterinary Basic Sciences, Royal Veterinary College, London, UK.
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18
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Cooke BA. Signal transduction involving cyclic AMP-dependent and cyclic AMP-independent mechanisms in the control of steroidogenesis. Mol Cell Endocrinol 1999; 151:25-35. [PMID: 10411317 DOI: 10.1016/s0303-7207(98)00255-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The control of steroidogenesis via signal transduction mechanisms involving cAMP-dependent and cAMP-independent mechanisms is reviewed. Several structurally unrelated factors that are potent stimulators of steroidogenesis whose actions do not require cAMP and/or synthesis of proteins have been identified. These include various interleukins, a lipophilic factor from macrophages, a steroidogenic inducing protein from follicular fluid and an imidazole compound, calmidazolium. All of these factors are capable of inducing maximum steroidogenesis. Calcium is required for steroidogenesis in all steroidogenic cells. With the exception of the effects of angiotensin II, there is little evidence for a role of IP3 in the stimulation of the release of calcium from intracellular stores in steroidogenic cells under physiological conditions. There may however, be a cAMP-mediated activation of a plasma membrane calcium channel. Chloride channels that can be regulated by cAMP-dependent and -independent mechanisms, are present in steroidogenic cells. Chloride ions exert a negative effect on steroidogenesis because exclusion of chloride from the extracellular medium markedly enhances cAMP-stimulated steroidogenesis. Arachidonic acid and its lipoxygenase products are involved in the control of steroidogenesis via cAMP mediated processes. An arachidonic acid related thioesterase has been isolated that is activated by ACTH and which may be involved in the release of arachidonic acid. It is concluded that while cAMP is a second messenger for LH/ACTH in the control of steroidogenesis, other signalling systems exist which are potentially equally effective in controlling steroidogenesis. In addition, the action of cAMP requires other signalling pathways involving calcium and chloride ions, as well as arachidonic acid and its lipoxygenase products.
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Affiliation(s)
- B A Cooke
- Department of Biochemistry and Molecular Biology, Royal Free and University College Medical School, University College London, UK.
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19
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Wang X, Walsh LP, Stocco DM. The role of arachidonic acid on LH-stimulated steroidogenesis and steroidogenic acute regulatory protein accumulation in MA-10 mouse Leydig tumor cells. Endocrine 1999; 10:7-12. [PMID: 10403565 DOI: 10.1385/endo:10:1:7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/1998] [Revised: 11/04/1998] [Accepted: 11/18/1998] [Indexed: 11/11/2022]
Abstract
Metabolic pathways leading to the production of arachidonic acid (AA) and its metabolites have been reported to have modulatory effects on steroidogenesis in a number of cell types. To examine the importance of the arachidonic acid pathway in steroid production and steroidogenic acute regulatory (StAR) protein expression, luteinizing hormones (LH) or N6-2-o-dibutyryl-adenosine-3:5-cyclic monophosphate-(Bt2cAMP) stimulated MA-10 mouse Leydig tumor cells were treated with various concentrations of quinacrine (an inhibitor of arachidonic acid production). Incubation of the cells with quinacrine resulted in dose-dependent decreases in steroid production and StAR protein. Twenty micromolars quinacrine inhibited 92 and 91% of LH-induced progesterone and StAR protein, respectively, and 98 and 90% of Bt2cAMP-induced progesterone and StAR protein. Reversal of this inhibition was obtained by incubation of quinacrine-treated cells with various levels of AA, which resulted in a dose-dependent increase in both steroid and StAR protein levels. Two hundred micromolars of AA rescued 57 and 60% of the LH-induced steroid production and StAR protein, respectively, and 52 and 89% of Bt2cAMP-induced steroid production and StAR protein. These results suggest that the effect of AA on LH- and cAMP-stimulated steroidogenesis is associated with the modulation of StAR protein expression.
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Affiliation(s)
- X Wang
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock 79430, USA
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20
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Finkielstein CV, Maloberti P, Mendez CF, Podestá EJ. A novel arachidonic acid-related thioesterase involved in acute steroidogenesis. Endocr Res 1998; 24:363-71. [PMID: 9888508 DOI: 10.3109/07435809809032616] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
We have reported the purification of a phosphoprotein (p43) intermediary in arachidonic acid release and steroid synthesis. Here we describe the cloning and sequencing of a cDNA encoding p43 as well as the hormonal regulation of the p43 transcript. The protein is homologous to a family of novel acyl-CoA thioesterases and identical to a peroxisome proliferator-inducible mitochondrial acyl-CoA thioesterase that shows highest substrate specificity for very-long-chain fatty acids such as arachidoyl- and palmitoyl-CoA. The deduced amino acid sequence of the protein has consensus sites for phosphorylation by different protein kinases, and a putative lipase serine motif. This motif is conserved in several species such as mouse, rat and human. Antibodies raised against a synthetic peptide that includes the lipase serine motif block the action of the protein. The transcript was induced by in vivo stimulation of the adrenals with ACTH. The effect of ACTH was rapid (5 min), reached a maximum (62%) at 15 min and returned to basal levels at 30 min. The effect was inhibited by actinomycin D and enhanced by cycloheximide. Our results provide the first evidence linking acyl-CoA thioesterases, with specificity for very-long-chain acids, and a protein intermediary in steroid synthesis, thereby supporting a regulatory role for acyl-CoA thioesterases in steroidogenic tissues. Given the obligatory role of the protein in the activation of steroidogenesis through arachidonic acid release, we propose the name Arachidonic acid- Related Thioesterase Involved in Steroidogenesis (ARTISt) for p43.
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Affiliation(s)
- C V Finkielstein
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Argentina
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21
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Marinero MJ, Penalva V, Oliva JL, Colás B, Prieto JC, López-Ruiz MP. Specific effect of arachidonic acid on 17beta-hydroxysteroid dehydrogenase in rat Leydig cells. FEBS Lett 1998; 422:10-4. [PMID: 9475159 DOI: 10.1016/s0014-5793(97)01584-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
It is well known that arachidonic acid (AA) acts as an intratesticular factor regulating luteinizing hormone-mediated testicular steroidogenesis. The present studies were conducted to determine the effect of AA on steroidogenic enzymes in rat Leydig cells. Exogenously added AA significantly inhibited 22(R)-hydroxy-cholesterol-stimulated testosterone production, which is a clear indication that AA is acting at some point after cholesterol transport to the inner mitochondrial membrane. AA failed to block the conversion of 22(R)-hydroxycholesterol to pregnenolone, indicating that the cytochrome P-450 side-chain cleavage enzyme complex is not the site of inhibition. The present results demonstrate that only 17beta-hydroxysteroid dehydrogenase seems to be involved in the AA action, since nearly 60% inhibition of testosterone production was found when the cells were incubated with androstenedione. Furthermore, no effect of AA was found when androstenediol was used as substrate in the testosterone synthesis, which indicates that 3beta-hydroxysteroid dehydrogenase is not affected by AA. The conversion of AA to its metabolites is not required for its action on 17beta-hydroxysteroid dehydrogenase and the activation of protein kinase C is not involved in the inhibitory effect.
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Affiliation(s)
- M J Marinero
- Unidad de Neuroendocrinologia Molecular, Departamento de Bioquímica y Biología Molecular, Universidad de Alcalá, Alcalá de Henares-Madrid, Spain
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22
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Mele PG, Dada LA, Paz C, Neuman I, Cymeryng CB, Mendez CF, Finkielstein CV, Cornejo Maciel F, Podestá EJ. Involvement of arachidonic acid and the lipoxygenase pathway in mediating luteinizing hormone-induced testosterone synthesis in rat Leydig cells. Endocr Res 1997; 23:15-26. [PMID: 9187535 DOI: 10.1080/07435809709031839] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Evidence has been introduced linking the lipoxygenase products and steroidogenesis in Leydig cells, thereby supporting that this pathway may be a common event in the hormonal control of steroid synthesis. On the other hand, it has also been reported that lipoxygenase products of arachidonic acid (AA) may not be involved in Leydig cells steroidogenesis. In this paper, we investigated the effects of PLA2 and lipoxygenase pathway inhibitors on steroidogenesis in rat testis Leydig cells. The effects of two structurally unrelated PLA2 inhibitors (4-bromophenacyl bromide (BPB) and quinacrine) were determined. BPB blocked the LH- and Bt2cAMP-stimulated testosterone production but had no effect on 22(4)-OH-cholesterol conversion to testosterone. Quinacrine caused a dose-dependent inhibition of LH- and Bt2cAMP-induced steroidogenesis. The effects of different lipoxygenase pathway inhibitors (nordihydroguaiaretic acid (NDGA), 5,8,11,14-eicosatetraynoic acid (ETYA), caffeic acid and esculetin) have also been determined. Both NDGA and ETYA inhibited LH- and Bt2cAMP-stimulated steroid synthesis in a dose-related manner. Furthermore caffeic acid and esculetin also blocked the LH-stimulated testosterone production. Moreover, exogenous AA induced a dose-dependent increase of testosterone secretion which was inhibited by NDGA. Our results strongly support the previous concept that the lipoxygenase pathway is involved in the mechanism of action of LH on testis Leydig cells.
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Affiliation(s)
- P G Mele
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Argentina
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23
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Marinero MJ, Colas B, Prieto JC, López-Ruiz MP. Different sites of action of arachidonic acid on steroidogenesis in rat Leydig cells. Mol Cell Endocrinol 1996; 118:193-200. [PMID: 8735605 DOI: 10.1016/0303-7207(96)03784-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The present study in purified rat Leydig cells shows that arachidonic acid may act as an intratesticular factor regulating LH-mediated testicular steroidogenesis. Arachidonic acid decreased, in a dose-dependent manner, the LH-stimulated cAMP and testosterone levels, over 2 h incubation. Incubation of Leydig cells with arachidonic acid did not modify 125I-hCG binding to the cells as compared to control, showing that the action of arachidonic acid is not related to a decrease of hCG binding to the cells. Forskolin-stimulated cAMP and testosterone production were inhibited by 51.65 and 70.9%, respectively, in the presence of arachidonic acid (100 microM), although the ED50 for the diterpene was not changed. When isobutyl-methyl-xanthine was added to the incubation medium, the same percentage of inhibition was found indicating that arachidonic acid inhibition of cAMP production is not due to stimulation of Leydig cell phosphodiesterase activity. Pretreatment of the cells with pertussis toxin, to inactivate Gi, was also without effect on arachidonic acid inhibition of LH-stimulated cAMP production, but pertussis toxin abolished the inhibitory effects of arachidonic acid when adenylate cyclase was stimulated with forskolin. However, arachidonic acid addition resulted in inhibition of LH- and forskolin-stimulated testosterone production, even if the cells were pretreated with pertussis toxin. It can be concluded that: (1) The inhibitory effect of arachidonic acid is neither due to a decrease of hCG binding to Leydig cells nor to a stimulation of cell phosphodiesterase activity; (2) arachidonic acid modulates cAMP production at two different levels, either by activation of Gi protein and by inhibition of Gs protein or adenylate cyclase; (3) the effect of arachidonic acid on steroidogenesis is also beyond cAMP formation.
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Affiliation(s)
- M J Marinero
- Departmento de Bioquímica y Biologia Molecular, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain
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24
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Mele PG, Dada LA, Paz C, Cymeryng CB, Cornejo Maciel MF, Neuman MI, Finkielstein CV, Mendez CF, Podestá EJ. Site of action of proteinases in the activation of steroidogenesis in rat adrenal gland. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1310:260-8. [PMID: 8599603 DOI: 10.1016/0167-4889(95)00177-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have investigated the effect of the proteinase inhibitors 1,10-phenantroline (OP) and phenylmethylsulfonyl fluoride (PMSF) on steroidogenesis in rat adrenal cortex. Both PMSF and OP inhibited adrenocorticotropin (ACTH)- and 8-Br cAMP-induced stimulation of corticosterone synthesis. On the contrary, arachidonic acid-induced stimulation of corticosterone synthesis was only slightly inhibited by PMSF and unchanged by OP. Intra- and extracellular cAMP levels were determined by radioimmunoassay. While PMSF did not affect neither the intra- nor the extracellular cAMP levels, OP decreased the intra- and extracellular levels of unstimulated as well as ACTH-stimulated cells. The site of action of the proteinase inhibitors was also studied by recombination of mitochondria with the different subcellular fractions in vitro. Addition of PMSF abolished the stimulation achieved by in vitro activation of cytosol by cAMP and PKA. On the other hand, OP completely inhibited the activation of mitochondria. Our results provide evidence for the involvement of proteinases in ACTH-induced stimulation of steroidogenesis in adrenal cortex both prior to the release of arachidonic acid and at the level of cholesterol transport from the outer to the inner mitochondrial membrane.
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Affiliation(s)
- P G Mele
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Argentina
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25
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Romanelli F, Valenca M, Conte D, Isidori A, Negro-Vilar A. Arachidonic acid and its metabolites effects on testosterone production by rat Leydig cells. J Endocrinol Invest 1995; 18:186-93. [PMID: 7615904 DOI: 10.1007/bf03347801] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Arachidonic acid (AA) seems to play an important role in testicular steroidogenesis, although controversial data exist in the literature. In the present study AA induced a dose related increase of testosterone (T) formation and, at the highest dose, stimulated the production of prostaglandin E2 (PGE2), leukotrienes B4 (LTB4) and C4 (LTC4) by purified rat Leydig cells. The contemporary addition of the prostaglandin synthesis blocker, indomethacin (IND), and AA further increased T formation, decreased PGE2 levels and did not modify LTB4 and LTC4 concentrations. The addition of a lipoxygenase inhibitor, nordihydroguaiaretic acid (NDGA, 5 microM), did not influence the stimulatory effect of AA on T and PGE2 formation while it decreased the output of LTB4 and LTC4. When 20 microM NDGA was used in addition to AA the expected reduction of leukotrienes release was observed together with a surprising impairment of T and PGE2 secretion. PGE2 and PGF2 alpha did not modify basal T production but reduced HCG-stimulated T secretion at the 10 nM dose. When 5-12- and 15-HETE were tested an enhancement of basal T formation was observed at the 10nM dose. 5-HETE (10nM) stimulated HCG-induced T production. LTA4, LTB4 and LTE4 did not influence basal T output while LTC4 and LTD4 inhibited it. LTC4 (10nM) induced a decrease of HCG-stimulated T production. These findings suggest that: 1) exogenous AA stimulates T secretion; 2) conversion of AA to cycloxygenated and lipoxygenated metabolites is not required for its steroidogenic effect; 3) cycloxygenated and lipoxygenated compounds play a diverse modulatory role on testicular steroidogenesis.
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Affiliation(s)
- F Romanelli
- Cattedra di Andrologia, Università di Roma La Sapienza, Italy
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26
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Paz C, Dada LA, Cornejo Maciel MF, Mele PG, Cymeryng CB, Neuman I, Mendez CF, Finkielstein CV, Solano AR, Park M. Purification of a novel 43-kDa protein (p43) intermediary in the activation of steroidogenesis from rat adrenal gland. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 224:709-16. [PMID: 7925388 DOI: 10.1111/j.1432-1033.1994.00709.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In previous reports we have demonstrated the presence of a soluble factor that responds to cAMP signals to induce steroid synthesis in adrenocortical tissue. Here, we describe the purification of this factor from adrenal zona fasciculata cells by using a five-step procedure that includes DEAE-cellulose, gel filtration, Mono Q HPLC and Superose HPLC, and elution of the protein from SDS/PAGE. This procedure results in the purification to homogeneity of a protein of 43-kDa that retains the capacity to stimulate steroid synthesis in an in vitro recombination assay. This activity is inhibited by the use of phospholipase A2 inhibitors. Antipeptide antibodies against the N-terminal region recognize p43 as a double band on SDS/PAGE that resolves in different spots on two-dimensional gel electrophoresis. Adrenocorticotropin treatment of adrenal glands results in the appearance of multiple spots that migrated towards a lower pH compared to controls, suggesting the presence of phosphorylated and dephosphorylated forms of p43. Sequencing of the N-terminal region and internal peptides reveals no significant similarities with other proteins, suggesting that p43 is a novel protein. We conclude from our data that the isolated protein (p43) is a novel, soluble protein that acts as intermediary in adrenocorticotropin-induced stimulation of arachidonic acid release and steroid synthesis.
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Affiliation(s)
- C Paz
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Argentina
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27
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Reddy GP, Prasad M, Sailesh S, Kumar YV, Reddanna P. Arachidonic acid metabolites as intratesticular factors controlling androgen production. INTERNATIONAL JOURNAL OF ANDROLOGY 1993; 16:227-33. [PMID: 8359939 DOI: 10.1111/j.1365-2605.1993.tb01184.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of inhibitors and products of arachidonic acid metabolism on rat testicular steroidogenesis has been investigated. In the presence of indomethacin (inhibitor of cyclooxygenase) and nordihydroguaiaretic acid (NDGA) (inhibitor of lipoxygenase), the activity of 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) were both inhibited. The LH-stimulated increase in secretion of testosterone and progesterone was also inhibited by indomethacin and NDGA. On the other hand, vitamin E (antioxidant and inhibitor of lipoxygenase), stimulated the activity of both 3 beta-HSD and 17 beta-HSD and enhanced LH-stimulated androgen production. The metabolites of lipoxygenase (15-HPETE, 15-HETE, 5-HPETE and 5-HETE) and cyclooxygenase (PGF2 alpha) pathways stimulated 3 beta-HSD and 17 beta-HSD activity and enhanced the secretion of progesterone and testosterone. It is concluded that arachidonic acid metabolites are intratesticular factors which can regulate LH-stimulated testicular steroidogenesis.
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Affiliation(s)
- G P Reddy
- School of Life Sciences, University of Hyderabad, India
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28
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Abstract
Luteinizing hormone (LH) interacts with its plasma membrane receptor to stimulate steroidogenesis not only via cyclic AMP but also other pathways which include arachidonic acid and leukotrienes and regulation of chloride and calcium channels. The same stimulatory pathways may lead to desensitization and down-regulation of the LH receptor and steroidogenesis. The LH receptor exists in a dynamic state, being truncated, or internalized, degraded or recycled. Desensitization is controlled by protein kinase C (PKC) in the rat and by cyclic AMP dependent protein kinase and PKC in the mouse Leydig cells. Using an adapted anti-sense oligonucleotide strategy we have shown that the cytoplasmic C-terminal sequence of the LH receptor is essential for desensitization to occur. In contrast, these sequences of the LH receptor are not required for the stimulation of cyclic AMP and steroid production. We have also shown that the extracellular domain of the LH receptor is secreted from the Leydig cell and may act as a LH-binding protein.
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Affiliation(s)
- B A Cooke
- Department of Biochemistry, Royal Free Hospital School of Medicine, London, England
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Dada LA, Paz C, Mele P, Solano AR, Cornejo Maciel F, Podesta EJ. The cytosol as site of phosphorylation of the cyclic AMP-dependent protein kinase in adrenal steroidogenesis. J Steroid Biochem Mol Biol 1991; 39:889-96. [PMID: 1661127 DOI: 10.1016/0960-0760(91)90346-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The mitochondria, the microsomes and the cytosol have been described as possible sites of cAMP-dependent phosphorylation. However, there has been no direct demonstration of a cAMP-dependent kinase associated with the activation of the side-chain cleavage of cholesterol. We have investigated the site of action of the cAMP-dependent kinase using a sensitive cell-free assay. Cytosol derived from cells stimulated with ACTH or cAMP was capable of increasing progesterone synthesis in isolated mitochondria when combined with the microsomal fraction. Cytosol derived from cyclase or kinase of negative mutant cells did not. Cyclic AMP and cAMP-dependent protein kinase stimulated in vitro a cytosol derived from unstimulated adrenal cells. This cytosol was capable of stimulating progesterone synthesis in isolated mitochondria. Inhibitor of cAMP-dependent protein kinase abolished the effect of the cAMP. ACTH stimulation of cytosol factors is a rapid process observable with a half maximal stimulation at about 3 pM ACTH. The effect was also abolished by inhibitor of arachidonic acid release. The function of cytosolic phosphorylation is still unclear. The effect of inhibitors of arachidonic acid release, and the necessity for the microsomal compartment in order to stimulate mitochondrial steroidogenesis, suggest that the factor in the cytosol may play a role in arachidonic acid release.
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Affiliation(s)
- L A Dada
- Department of Biochemistry, School of Medicine, University of Buenos Aires, Argentina
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Abayasekara DR, Band AM, Cooke BA. Evidence for the involvement of phospholipase A2 in the regulation of luteinizing hormone-stimulated steroidogenesis in rat testis Leydig cells. Mol Cell Endocrinol 1990; 70:147-53. [PMID: 2161362 DOI: 10.1016/0303-7207(90)90154-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In this study the effects of modulating the release of arachidonic acid by phospholipase A2 (PLA2) on luteinizing hormone (LH)-stimulated testosterone production in rat testis Leydig cells have been investigated. Exogenously added PLA2 significantly stimulated both basal and LH-stimulated testosterone production. The effects of three structurally unrelated PLA2 inhibitors (dexamethasone, quinacrine and p-bromophenacyl bromide (pBPB)) were determined. Dexamethasone and quinacrine caused a dose-dependent inhibition of LH-induced testosterone production but had no effect on LH-induced cyclic AMP accumulation. Dibutyryl cyclic AMP-, and forskolin-stimulated testosterone production were also inhibited by all three inhibitors used. 22R-OH-cholesterol-stimulated testosterone production was not inhibited by quinacrine or dexamethasone showing that they were not exerting their inhibitory effect on LH-induced testosterone production by decreasing the activity of the steroidogenic enzymes. However, pBPB exerted an inhibitory effect on LH-induced testosterone and cyclic AMP production. Furthermore pBPB also inhibited 22R-OH-cholesterol-induced testosterone production illustrating that apart from its well-documented effect on PLA2, it also exerts a direct inhibitory effect on the steroidogenic enzymes. The finding that PLA2 inhibitors inhibit testosterone production without affecting cyclic AMP accumulation provides further indirect evidence for second messengers in addition to cyclic AMP being involved in the action of LH in Leydig cells. These results indicate that PLA2 is involved in LH-induced testosterone production and that cyclic AMP may exert its actions via this pathway.
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Affiliation(s)
- D R Abayasekara
- Department of Biochemistry, Royal Free Hospital School of Medicine, London, U.K
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31
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Patterson TR, Stringham JD, Meikle AW. Nicotine and cotinine inhibit steroidogenesis in mouse Leydig cells. Life Sci 1990; 46:265-72. [PMID: 2154652 DOI: 10.1016/0024-3205(90)90032-m] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cigarette smoking alters plasma testosterone concentrations in men. The objectives of this study were to determine if nicotine and cotinine, two alkaloid products of cigarettes, affect luteinizing hormone(LH)-stimulated steroidogenesis in isolated adult mouse Leydig cells. Leydig cells from adult Swiss-Webster mice were isolated by linear density gradient and incubated (95% O2, 5% CO2) in minimum essential medium at 37 C for 3 hours with LH (10 ng) and with or without nicotine or cotinine (10(-5)-10(-7) M). Both nicotine and cotinine produced dose response inhibition (P less than 0.05) of LH-stimulated testosterone production (50-70%). The addition of 8-bromo-3',5'-cyclic monophosphate (cAMP, 500 uM) stimulated steroidogenesis comparable to LH in the absence of the alkaloids, but both nicotine and cotinine significantly (P less than 0.05) reduced testosterone production in response to cAMP, suggesting that the alkaloids inhibit testosterone production in response to LH distal to the formation of cAMP. In MEM without calcium, LH-stimulated testosterone synthesis was decreased, and neither nicotine nor cotinine significantly affected steroidogenesis. The addition of a calcium ionophore in MEM with normal calcium content enhanced (P less than 0.05) the inhibitory effects of nicotine and cotinine on LH-responsive steroidogenesis. A calcium channel blocking agent, verapamil, at 10uM significantly (P less than 0.05) reversed the inhibition of LH-stimulated testosterone production produced by both alkaloids when incubated in the medium with a normal calcium concentration. These results suggest that nicotine and cotinine either affect intracellular calcium content or block the effects of calcium on steroidogenesis in mouse Leydig cells.
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Affiliation(s)
- T R Patterson
- Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City 84132
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Meikle AW, Benson SJ, Liu XH, Boam WD, Stringham JD. Nonesterified fatty acids modulate steroidogenesis in mouse Leydig cells. THE AMERICAN JOURNAL OF PHYSIOLOGY 1989; 257:E937-42. [PMID: 2558577 DOI: 10.1152/ajpendo.1989.257.6.e937] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effects of nonesterified fatty acids (NEFA) in modulating testosterone synthesis stimulated by luteinizing hormone (LH, 10 ng/sample) were investigated in isolated adult mouse Leydig cells. LH-stimulated testosterone production was inhibited by triglycerides (0-500 mg/dl, 50 mg/dl, 94% of the control and 500 mg/dl, 40%) and by a mixture of NEFA (100 microM, 70% of control, 200 microM, 54%, and greater than 200 microM, less than 50%). Oleic acid was a more potent inhibitor than linoleic, stearic, or palmitic acids. 8-Bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP, 5 mM) stimulated testosterone production comparable to LH but failed to reverse the inhibition of steroidogenesis produced by the NEFA. The inhibition produced by NEFA was dependent on extracellular Ca2+; and a Ca2+ channel antagonist, verapamil (10 microM), enhanced the inhibition of chylomicrons and fatty acids. 22(R)-hydroxycholesterol (10 microM) reversed the inhibition produced by NEFA. The inhibitory effects of NEFA were reversible by removal of the fatty acids. The results indicate that NEFA are potent modulators of testosterone synthesis in Leydig cells stimulated with either LH, cAMP, or intracellular Ca2+. NEFA inhibit steroidogenesis at one of the steps preceding conversion of cholesterol to pregnenolone.
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Affiliation(s)
- A W Meikle
- Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City 84132
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Didolkar AK, Sundaram K. Mechanism of LHRH-stimulated steroidogenesis in rat Leydig cells: lipoxygenase products of arachidonic acid may not be involved. JOURNAL OF ANDROLOGY 1989; 10:449-55. [PMID: 2695506 DOI: 10.1002/j.1939-4640.1989.tb00138.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Luteinizing hormone releasing hormone agonist, [(imBzl)-DHis6,Pro9,NEt]-LHRH (LHRH-A), caused a two to threefold increase in in vitro testosterone (T) secretion by rat Leydig cells. This LHRH-A-induced T secretion was completely blocked by quinacrine and chloroquine, inhibitors of phospholipase A2. Addition of phospholipase A2, however, was ineffective in stimulating basal or LHRH-A-induced T secretion. Phospholipase C, on the other hand, significantly stimulated both basal and LHRH-A-induced T secretion. Exogenously added arachidonic acid stimulated basal T secretion in a dose dependent manner, the maximum increase being about 100% over basal at a dose of 100 microM. Higher doses of arachidonic acid had no stimulatory effect. In the presence of LHRH-A, the stimulatory effect of arachidonic acid was additive up to a concentration of 100 microM; but higher concentrations of arachidonic acid (200 microM) were inhibitory. LHRH-A-induced steroidogenesis was inhibited by 5, 8, 11, 14 Eicosatetraynoic acid (ETYA), an inhibitor of all the three known pathways of arachidonic acid metabolism, and by nordihydroguaiaretic acid, and inhibitory of the lipoxygenase pathway of arachidonic acid metabolism. LHRH-A-stimulated T secretion was not inhibited by indomethacin, an inhibitor of the cyclo-oxygenase pathway of arachidonic acid metabolism. ETYA inhibited arachidonic acid-induced T secretion. Nordihydroguaiaretic acid, on the other hand, augmented basal, arachidonic acid-, phospholipase C-, or phorbol 12, myristate 13 acetate-induced testosterone secretion. These results suggest that arachidonic acid, whose release is influenced by phospholipase C, is involved in LHRH-A-induced T secretion by rat Leydig cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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