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Kotarba G, Zielinska-Gorska M, Biernacka K, Gajewska A. Gonadotropin-releasing hormone-Cu complex (Cu-GnRH) transcriptional activity in vivo in the female rat anterior pituitary gland. Brain Res Bull 2020; 156:67-75. [PMID: 31931118 DOI: 10.1016/j.brainresbull.2020.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 12/23/2019] [Accepted: 01/03/2020] [Indexed: 12/01/2022]
Abstract
Unlike gonadotropin-releasing hormone (GnRH) analogues characterized by amino acid replacement in decapeptide primary structure, Cu-GnRH molecule preserves the native sequence but contains a Cu2+ ion stably bound to the nitrogen atoms including that of the imidazole ring of His2. Cu-GnRH can operate via cAMP/PKA signalling in anterior pituitary cells, suggesting that it may affect selected gonadotropic network gene transcription in vivo. We analysed pituitary mRNA expression of Egr-1, Nr5a1, and Lhb based on their role in luteinizing hormone (LH) synthesis; and Nos1, Adcyap1, and Prkaca due to their dependence on cAMP/PKA activity. In two independent experiments, ovariectomized rats received intracerebroventricular pulsatile (one pulse/h or two pulses/h over 5 h) microinjections of 2 nM Cu-GnRH; 2 nM antide (GnRH antagonist) + 2 nM Cu-GnRH; 100 nM PACAP6-38 (PACAP receptor antagonist) + 2 nM Cu-GnRH. Relative expression of selected mRNAs was determined by qRT-PCR. LH serum concentration was examined according to RIA. All examined genes responded to Cu-GnRH stimulation with increased transcriptional activity in a manner dependent on pulse frequency pattern. Increased expression of Nr5a1, Lhb, Nos1, Adcyap1, and Prkaca mRNA was observed solely in rats receiving the complex with frequency of two pulses/h over 5 h. Egr-1 transcription was up-regulated for both applied Cu-GnRH pulsatile patterns. The stimulatory effect of Cu-GnRH on gene transcription was dependent on both GnRH receptor and PAC-1 activation. In conclusion, obtained results indicate that Cu-GnRH complex is a GnRH analogue able to induce both IP3/PKC and cAMP/PKA-dependent gonadotrope network gene transcription in vivo.
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Affiliation(s)
- Grzegorz Kotarba
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 3 Instytucka St., 05-110 Jablonna, Poland.
| | - Marlena Zielinska-Gorska
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 3 Instytucka St., 05-110 Jablonna, Poland.
| | - Katarzyna Biernacka
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 3 Instytucka St., 05-110 Jablonna, Poland
| | - Alina Gajewska
- Department of Animal Physiology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 3 Instytucka St., 05-110 Jablonna, Poland.
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Gajewska A, Zielinska-Gorska M, Wolinska-Witort E, Siawrys G, Baran M, Kotarba G, Biernacka K. Intracellular mechanisms involved in copper-gonadotropin-releasing hormone (Cu-GnRH) complex-induced cAMP/PKA signaling in female rat anterior pituitary cells in vitro. Brain Res Bull 2015; 120:75-82. [PMID: 26551063 DOI: 10.1016/j.brainresbull.2015.11.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 10/31/2015] [Accepted: 11/03/2015] [Indexed: 01/24/2023]
Abstract
The copper-gonadotropin-releasing hormone molecule (Cu-GnRH) is a GnRH analog, which preserves its amino acid sequence, but which contains a Cu(2+) ion stably bound to the nitrogen atoms including that of the imidazole ring of Histidine(2). A previous report indicated that Cu-GnRH was able to activate cAMP/PKA signaling in anterior pituitary cells in vitro, but raised the question of which intracellular mechanism(s) mediated the Cu-GnRH-induced cAMP synthesis in gonadotropes. To investigate this mechanism, in the present study, female rat anterior pituitary cells in vitro were pretreated with 0.1 μM antide, a GnRH antagonist; 0.1 μM cetrorelix, a GnRH receptor antagonist; 0.1 μM PACAP6-38, a PAC-1 receptor antagonist; 2 μM GF109203X, a protein kinase C inhibitor; 50 mM PMA, a protein kinase C activator; the protein kinase A inhibitors H89 (30 μM) and KT5720 (60 nM); factors affecting intracellular calcium activity: 2.5 mM EGTA; 2 μM thapsigargin; 5 μM A23187, a Ca(2+) ionophore; or 10 μg/ml cycloheximide, a protein synthesis inhibitor. After one of the above pretreatments, cells were incubated in the presence of 0.1 μM Cu-GnRH for 0.5, 1, and 3 h. Radioimmunoassay analysis of cAMP confirmed the functional link between Cu-GnRH stimulation and cAMP/PKA signal transduction in rat anterior pituitary cells, demonstrating increased intracellular cAMP, which was reduced in the presence of specific PKA inhibitors. The stimulatory effect of Cu-GnRH on cAMP production was partly dependent on GnRH receptor activation. In addition, an indirect and Ca(2+)-dependent mechanism might be involved in intracellular adenylate cyclase stimulation. Neither activation of protein kinase C nor new protein synthesis was involved in the Cu-GnRH-induced increase of cAMP in the rat anterior pituitary primary cultures. Presented data indicate that conformational changes of GnRH molecule resulting from cooper ion coordination affect specific pharmacological properties of Cu-GnRH molecule including specific pattern of intracellular activity induced by complex in anterior pituitary cells in vitro.
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Affiliation(s)
- Alina Gajewska
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland.
| | - Marlena Zielinska-Gorska
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland
| | - Ewa Wolinska-Witort
- Neuroendocrinology Department, Medical Centre for Postgraduate Education, Marymoncka 99/103 st., 01-813 Warsaw, Poland
| | - Gabriela Siawrys
- Department of Animal Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A st. 10-719 Olsztyn, Poland
| | - Marta Baran
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland
| | - Grzegorz Kotarba
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland
| | - Katarzyna Biernacka
- Department of Neuroendocrinology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, 05-110 Jablonna n. Warsaw, Poland
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Miska-Schramm A, Kruczek M, Kapusta J. Effect of copper exposure on reproductive ability in the bank vole (Myodes glareolus). ECOTOXICOLOGY (LONDON, ENGLAND) 2014; 23:1546-1554. [PMID: 25098774 DOI: 10.1007/s10646-014-1295-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/22/2014] [Indexed: 06/03/2023]
Abstract
The amount of copper in natural ecosystems is steadily increasing, due to human activities. It accumulates in plants, posing a threat to herbivores. In polluted areas the population density of small rodents is observed to be lower. The decline in rodent numbers may be caused by increased mortality or diminished fertility. This study examined the effect of copper on the reproductive activity of the bank vole (Myodes glareolus), a small rodent which during foraging often wanders into fields where it might be exposed to pollution. The animals were treated with solutions of 0, 150 or 600 ppm Cu. After 12 weeks of exposure the quality and quantity of the male's sperm was tested. To assess morphological development we compared the experimental groups for body weight, the weight of the male's testes and accessory sex glands, the female's uterus, and the number of matured ovary follicles in tested females. At both doses, copper administration led to lower sperm count and caused sperm head anomalies. The higher dose compromised sperm tail membrane integrity, viability and motility. No effect of copper on morphological development was observed in males, and only the lower dose increased testes weight. In females the higher dose had a negative effect on morphological development, and the lower dose increased uterus weight. No effect of copper on ovarian follicle number was found. For the first time, the morphology of the most typical ovarian follicles of the bank vole is presented.
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Affiliation(s)
- Agata Miska-Schramm
- Institute of Environmental Sciences, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland,
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Kamysz E, Kotynia A, Czyżnikowska Ż, Jaremko M, Jaremko Ł, Nowakowski M, Brasun J. Sialorphin and its analog as ligands for copper(II) ions. Polyhedron 2013. [DOI: 10.1016/j.poly.2012.10.055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Arpasova H, Capcarova M, Kalafova A, Lukac N, Kovacik J, Formicki G, Massanyi P. Nickel induced alteration of hen body weight, egg production and egg quality after an experimental peroral administration. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2007; 42:913-918. [PMID: 17978960 DOI: 10.1080/03601230701623662] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In this study the effects of nickel (NiCl2) administered in drinking water (0.02; 0.2 and 2.0 mg NiCl2/L for 28 days) on laying hen body weight, egg production and egg quality is reported. Growth parameters during the experiment were significantly decreased mainly in the group with the highest nickel concentration. In total egg production dose-dependent decrease in all experimental groups was found. Egg weight was mainly affected in the group with the highest nickel concentration. Specific egg weight was not altered. Albumen weight and albumen content was significantly decreased in groups with the highest nickel concentration in comparison with the control group. Egg yolk analysis detected significantly decreased yolk weight in the group with the highest nickel experimental level. In yolk color a significant difference was detected between the group receiving 0.02 and 0.2 mg NiCl2/mL. Eggshell compactness was increased in all experimental groups what could be induced by altered mineralization of eggshell. Results of this study clearly report a negative effect of nickel as an environmental pollutant on laying hen body weight, egg production as well as egg quality.
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Affiliation(s)
- Henrieta Arpasova
- Department of Poultry Science and Small Animal Husbandry, Slovak Agricultural University, Nitra, Slovak Republic
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D'Amelio N, Gaggelli E, Gajewska A, Kochman H, Kochman K, Kozlowski H, Latajka Z, Mlynarz P, Panek J, Valensin G. Structural analysis and sheep pituitary receptor binding of GnRH and its complexes with metal ions. J Inorg Biochem 2003; 94:28-35. [PMID: 12620670 DOI: 10.1016/s0162-0134(02)00630-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Binding of GnRH and its metal complexes to a sheep pituitary receptor have been investigated showing that Cu(II)-GnRH complex is more effectively bound to the receptor than the metal-free ligand, while Ni(II) and Co(II) complexes are less effective than the metal-free GnRH. Earlier studies have explained reasonably well the complex formation with cupric ion, while in this work extensive 1H NMR measurements have been performed for free gonadotropin-releasing hormone (GnRH) and its complexes with Ni(II) in DMSO (dimethyl sulfoxide) solution. This study shows the high order of organization of the metal-free peptide in DMSO solution with two structured 'domains' whose relative orientation is modulated by the mobility of the central glycine. Furthermore, theoretical calculations were performed for the Ni(II)-GnRH complex. The data obtained in this work supports previous studies on the co-ordination of Ni(II) ions with GnRH in aqueous solutions at high pH [J. Inorg. Biochem. 33 (1988) 11] and suggest an experimental procedure to reproduce high pH in DMSO solution. In the Ni(II) complex, the metal ion was found to co-ordinate with four nitrogen atoms inducing a well definite arrangement of aromatic side-chains and a rigid backbone structure.
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Affiliation(s)
- Nicola D'Amelio
- Dipartimento di Chimica e Centro NMR, Università di Siena, Via Aldo Moro, 53100, Siena, Italy
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Kochman K, Gajewska A, Kochman H, Kozłowski H, Masiukiewicz E, Rzeszotarska B. Binding of Cu2+, Zn2+, and Ni(2+)-GnRH complexes with the rat pituitary receptor. J Inorg Biochem 1997; 65:277-9. [PMID: 9046108 DOI: 10.1016/s0162-0134(96)00143-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Complex of copper with the gonadotropin-releasing hormone, GnRH, competed more efficiently for the GnRH receptor than native GVRH, while complexes of nickel with GnRH and zinc with GnRH had slightly lower affinity. Copper ion added to the incubation mixture inhibited the buserelin binding to the receptor.
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Affiliation(s)
- K Kochman
- Institute of Animal Physiology and Nutrition, Jabłonna, Poland
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Bal W, Kozlowski H, Kupryszewski G, Mackiewicz Z, Pettit L, Robbins R. Complexes of Cu(II) with Asn-Ser-Phe-Arg-Tyr-NH2; an example of metal ion-promoted conformational organization which results in exceptionally high complex stability. J Inorg Biochem 1993; 52:79-87. [PMID: 8254337 DOI: 10.1016/0162-0134(93)85024-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The pentapeptide fragment of ANF, Asn-Ser-Phe-Arg-Tyr-NH2, coordinates to Cu(II) using the same four nitrogen donor centers as simple pentapeptides such as pentaalanine yet the complexes are of much higher stability as a result of a highly organized side-chain structure which is present in the complex but absent from the free ligand.
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Affiliation(s)
- W Bal
- Institute of Chemistry, University of Wroclaw, Poland
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