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Do urocortins have a role in treating cardiovascular disease? Drug Discov Today 2019; 24:279-284. [DOI: 10.1016/j.drudis.2018.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Revised: 08/20/2018] [Accepted: 09/05/2018] [Indexed: 02/02/2023]
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Tan LA, Vaughan JM, Perrin MH, Rivier JE, Sawchenko PE. Distribution of corticotropin-releasing factor (CRF) receptor binding in the mouse brain using a new, high-affinity radioligand, [125I]-PD-Sauvagine. J Comp Neurol 2017; 525:3840-3864. [DOI: 10.1002/cne.24307] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 08/15/2017] [Accepted: 08/16/2017] [Indexed: 01/30/2023]
Affiliation(s)
- Laura A. Tan
- Laboratory of Neuronal Structure and Function; The Salk Institute for Biological Studies; La Jolla CA
| | - Joan M. Vaughan
- Laboratory of Neuronal Structure and Function; The Salk Institute for Biological Studies; La Jolla CA
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies; La Jolla CA
| | - Marilyn H. Perrin
- Laboratory of Neuronal Structure and Function; The Salk Institute for Biological Studies; La Jolla CA
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies; La Jolla CA
| | - Jean E. Rivier
- Clayton Foundation Laboratories for Peptide Biology, The Salk Institute for Biological Studies; La Jolla CA
| | - Paul E. Sawchenko
- Laboratory of Neuronal Structure and Function; The Salk Institute for Biological Studies; La Jolla CA
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Williams TA, Bergstrome JC, Scott J, Bernier NJ. CRF and urocortin 3 protect the heart from hypoxia/reoxygenation-induced apoptosis in zebrafish. Am J Physiol Regul Integr Comp Physiol 2017; 313:R91-R100. [PMID: 28539353 PMCID: PMC5582954 DOI: 10.1152/ajpregu.00045.2017] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/08/2017] [Accepted: 05/18/2017] [Indexed: 12/20/2022]
Abstract
Fish routinely experience environmental hypoxia and have evolved various strategies to tolerate this challenge. Given the key role of the CRF system in coordinating the response to stressors and its cardioprotective actions against ischemia in mammals, we sought to characterize the cardiac CRF system in zebrafish and its role in hypoxia tolerance. We established that all genes of the CRF system, the ligands CRFa, CRFb, urotensin 1 (UTS1), and urocortin 3 (UCN3); the two receptor subtypes (CRFR1 and CRFR2); and the binding protein (CRFBP) are expressed in the heart of zebrafish: crfr1 > crfr2 = crfbp > crfa > ucn3 > crfb > uts1 In vivo, exposure to 5% O2 saturation for 15 min and 90 min of recovery resulted in four- to five-fold increases in whole heart crfb and ucn3 mRNA levels but did not affect the gene expression of other CRF system components. In vitro, as assessed by monitoring caspase 3 activity and the number of terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells, pretreatment of excised whole hearts with CRF or UCN3 for 30 min prevented the increase in apoptosis associated with exposure to 1% O2 saturation for 30 min with a 24-h recovery. Lastly, the addition of the nonselective CRF receptor antagonist αh-CRF(9-41) prevented the cytoprotective effects of CRF. We show that the CRF system is expressed in fish heart, is upregulated by hypoxia, and is cytoprotective. These findings identify a novel role for the CRF system in fish and a new strategy to tolerate hypoxia.
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Affiliation(s)
- Tegan A Williams
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Jillian C Bergstrome
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Juliana Scott
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Nicholas J Bernier
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
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Perrin MH, Tan LA, Vaughan JM, Lewis KA, Donaldson CJ, Miller C, Erchegyi J, Rivier JE, Sawchenko PE. Characterization of a Pachymedusa dacnicolor-Sauvagine analog as a new high-affinity radioligand for corticotropin-releasing factor receptor studies. J Pharmacol Exp Ther 2015; 353:307-17. [PMID: 25736419 DOI: 10.1124/jpet.114.222307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The corticotropin-releasing factor (CRF) peptide family comprises the mammalian peptides CRF and the urocortins as well as frog skin sauvagine and fish urophyseal urotensin. Advances in understanding the roles of the CRF ligand family and associated receptors have often relied on radioreceptor assays using labeled CRF ligands. These assays depend on stable, high-affinity CRF analogs that can be labeled, purified, and chemically characterized. Analogs of several of the native peptides have been used in this context, most prominently including sauvagine from the frog Phyllomedusa sauvageii (PS-Svg). Because each of these affords both advantages and disadvantages, new analogs with superior properties would be welcome. We find that a sauvagine-like peptide recently isolated from a different frog species, Pachymedusa dacnicolor (PD-Svg), is a high-affinity agonist whose radioiodinated analog, [(125)ITyr(0)-Glu(1), Nle(17)]-PD-Svg, exhibits improved biochemical properties over those of earlier iodinated agonists. Specifically, the PD-Svg radioligand binds both CRF receptors with comparably high affinity as its PS-Svg counterpart, but detects a greater number of sites on both type 1 and type 2 receptors. PD-Svg is also ∼10 times more potent at stimulating cAMP accumulation in cells expressing the native receptors. Autoradiographic localization using the PD-Svg radioligand shows robust specific binding to rodent brain and peripheral tissues that identifies consensus CRF receptor-expressing sites in a greater number and/or with greater sensitivity than its PS-Svg counterpart. We suggest that labeled analogs of PD-Svg may be useful tools for biochemical, structural, pharmacological, and anatomic studies of CRF receptors.
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Affiliation(s)
- Marilyn H Perrin
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Laura A Tan
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Joan M Vaughan
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Kathy A Lewis
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Cynthia J Donaldson
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Charleen Miller
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Judit Erchegyi
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Jean E Rivier
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
| | - Paul E Sawchenko
- Clayton Foundation Laboratories for Peptide Biology (M.H.P., J.M.V., K.A.L., C.J.D., C.M., J.E., J.E.R., P.E.S.) and Laboratory of Neuronal Structure and Function (L.A.T., P.E.S.), The Salk Institute for Biological Studies, La Jolla, California
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Devetzis V, Zarogoulidis P, Kakolyris S, Vargemezis V, Chatzaki E. The corticotropin releasing factor system in the kidney: perspectives for novel therapeutic intervention in nephrology. Med Res Rev 2012; 33:847-72. [PMID: 22622997 DOI: 10.1002/med.21268] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The adaptation to endogenous and exogenous stress stimuli is crucial for survival but also for the onset of various diseases in humans. Corticotropin releasing factor (CRF) system is the major regulator of stress response and homeostasis. The members of this family of peptides extend their actions also outside CNS to the periphery where they may affect various body systems independently, acting via vagal and/or autocrine/paracrine pathways. In search for peripheral targets, kidney has rarely been studied separately, regarding expression and action of CRF and CRF-related peptides. We reviewed the existing literature concerning expression and action of the CRF system in normal and pathological renal tissue and explored possible clinical implications in nephrology. CRF system components are expressed in the kidney of experimental animals and in humans. The intrarenal distribution is reported to be equally extensive, suggesting a physiological or pathophysiological role in renal function and in the occurrence of renal disease. Urocortins have given multiple interesting observations in experimental models of renal disease and clinical studies, showing robust effects in renal regulation mechanisms. We summarize the relevant data and put them in context, proposing applications with clinical significance in the field of hypertension, diabetic nephropathy, chronic kidney disease, cardiorenal syndrome, and peritoneal dialysis.
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Affiliation(s)
- Vassilis Devetzis
- Laboratory of Pharmacology, Faculty of Medicine, Democritus University of Thrace, Alexandroupolis, Greece
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Yang LZ, Kockskämper J, Khan S, Suarez J, Walther S, Doleschal B, Unterer G, Khafaga M, Mächler H, Heinzel FR, Dillmann WH, Pieske B, Spiess J. cAMP- and Ca²(+) /calmodulin-dependent protein kinases mediate inotropic, lusitropic and arrhythmogenic effects of urocortin 2 in mouse ventricular myocytes. Br J Pharmacol 2011; 162:544-56. [PMID: 20942811 PMCID: PMC3031072 DOI: 10.1111/j.1476-5381.2010.01067.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 08/11/2010] [Accepted: 09/07/2010] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Urocortin 2 is beneficial in heart failure, but the underlying cellular mechanisms are not completely understood. Here we have characterized the functional effects of urocortin 2 on mouse cardiomyocytes and elucidated the underlying signalling pathways and mechanisms. EXPERIMENTAL APPROACH Mouse ventricular myocytes were field-stimulated at 0.5 Hz at room temperature. Fractional shortening and [Ca²(+)](i) transients were measured by an edge detection and epifluorescence system respectively. Western blots were carried out on myocyte extracts with antibodies against total phospholamban (PLN) and PLN phosphorylated at serine-16. KEY RESULTS Urocortin 2 elicited time- and concentration-dependent positive inotropic and lusitropic effects (EC₅₀ : 19 nM) that were abolished by antisauvagine-30 (10 nM, n= 6), a specific antagonist of corticotrophin releasing factor (CRF) CRF₂ receptors. Urocortin 2 (100 nM) increased the amplitude and decreased the time constant of decay of the underlying [Ca²(+)](i) transients. Urocortin 2 also increased PLN phosphorylation at serine-16. H89 (2 µM) or KT5720 (1 µM), two inhibitors of protein kinase A (PKA), as well as KN93 (1 µM), an inhibitor of Ca²(+)/calmodulin-dependent protein kinase II (CaMKII), suppressed the urocortin 2 effects on shortening and [Ca²(+)](i) transients. In addition, urocortin 2 also elicited arrhythmogenic events consisting of extra cell shortenings and extra [Ca²(+)](i) increases in diastole. Urocortin 2-induced arrhythmogenic events were significantly reduced in cells pretreated with KT5720 or KN93. CONCLUSIONS AND IMPLICATIONS Urocortin 2 enhanced contractility in mouse ventricular myocytes via activation of CRF₂ receptors in a cAMP/PKA- and Ca²(+)/CaMKII-dependent manner. This enhancement was accompanied by Ca²(+)-dependent arrhythmogenic effects mediated by PKA and CaMKII.
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Affiliation(s)
- Li-Zhen Yang
- Molecular Neuroendocrinology Group, Max Planck Institute for Experimental MedicineGoettingen, Germany
- Division of Endocrinology and Metabolism, School of Medicine, University of CaliforniaSan Diego, CA, USA
- Specialized Neuroscience Research Program 2 of the John A. Burns School of Medicine of the University of Hawaii at ManoaHonolulu, HI, USA
- Division of Endocrinology, Department of Internal Medicine, Shanghai Ninth People's Hospital of Shanghai Jiaotong UniversityShanghai, China
| | - Jens Kockskämper
- Division of Cardiology, Medical University of GrazAuenbruggerplatz, Graz, Austria
- Institute of Pharmacology and Clinical Pharmacy, Philipps-University of MarburgMarburg, Germany
| | - Shelina Khan
- Division of Cardiology, Medical University of GrazAuenbruggerplatz, Graz, Austria
| | - Jorge Suarez
- Division of Endocrinology and Metabolism, School of Medicine, University of CaliforniaSan Diego, CA, USA
| | - Stefanie Walther
- Division of Cardiology, Medical University of GrazAuenbruggerplatz, Graz, Austria
| | - Bernhard Doleschal
- Division of Cardiology, Medical University of GrazAuenbruggerplatz, Graz, Austria
| | - Gregor Unterer
- Division of Cardiology, Medical University of GrazAuenbruggerplatz, Graz, Austria
| | - Mounir Khafaga
- Division of Cardiology, Medical University of GrazAuenbruggerplatz, Graz, Austria
| | - Heinrich Mächler
- Division of Cardiac Surgery, Medical University of GrazAuenbruggerplatz, Graz, Austria
| | - Frank R Heinzel
- Division of Cardiology, Medical University of GrazAuenbruggerplatz, Graz, Austria
| | - Wolfgang H Dillmann
- Division of Endocrinology and Metabolism, School of Medicine, University of CaliforniaSan Diego, CA, USA
| | - Burkert Pieske
- Division of Cardiology, Medical University of GrazAuenbruggerplatz, Graz, Austria
| | - Joachim Spiess
- Molecular Neuroendocrinology Group, Max Planck Institute for Experimental MedicineGoettingen, Germany
- Specialized Neuroscience Research Program 2 of the John A. Burns School of Medicine of the University of Hawaii at ManoaHonolulu, HI, USA
- Sanford Burnham Medical Research InstituteLa Jolla, CA, USA
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Boucher W, Kempuraj D, Michaelian M, Theoharides TC. Corticotropin-releasing hormone-receptor 2 is required for acute stress-induced bladder vascular permeability and release of vascular endothelial growth factor. BJU Int 2010; 106:1394-9. [PMID: 20201838 DOI: 10.1111/j.1464-410x.2010.09237.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE To investigate the corticotropin-releasing hormone (CRH) receptor (CRH-R) requirement for the effect of acute stress on bladder vascular permeability and release of vascular endothelial growth factor (VEGF), as increasing evidence indicates that acute stress worsens certain inflammatory disorders, including interstitial cystitis/painful bladder syndrome (IC/PBlS), which is characterized by pain, variable bladder inflammation, increased expression of bladder vascular endothelial growth factor (VEGF), and many detrusor mast cells. MATERIALS AND METHODS Bladders of normal C57BL/6, and C57BL/6- derived CRH-R1, CRH-R2 or double CRH-R1 + 2 knockout (-/-) female mice (10-12 weeks old) were catheterized under anaesthesia. After emptying the urine, normal saline was instilled with or without intravesical CRH-R antagonists in C57BL/6 mice before they were stressed by placing them in a restrainer for 30 min. Evans blue was injected in the tail vein before stress for the permeability experiments. The bladders from C57BL/6 or CRH-R -/- mice were then removed, minced into 1 mm(2) pieces and cultured overnight. Culture media were collected 24 h later for VEGF assay. C57BL/6 bladder was processed for CRH-R immunohistochemistry. RESULTS Acute stress increased bladder vascular permeability in control C57BL/6 and CRH-R1 -/- mice, but not CRH-R2 -/- or CRH-R1+2 -/- mice. The CRH-R2 antagonist Astressin 2B, but not the CRH-R1 antagonist Antalarmin, inhibited stress-induced VEGF release from C57BL/6 mouse bladder explants. Stress could not induce a VEGF increase from bladder explants of CRH-R2 -/- or CRH-R1+2 -/- mice, but did so in CRH-R1 -/- mice. Bladder CRH-R2 immunoreactivity was detected in C57BL/6 bladders. CONCLUSIONS Acute stress induces bladder vascular permeability and VEGF release that is dependent on CRH-R2. These findings suggest that CRH and VEGF might participate in the pathogenesis of IC/PBlS and provide for new therapeutic targets.
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Affiliation(s)
- William Boucher
- Molecular Immunopharmacology and Drug Discovery Laboratory, Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, MA 02111, USA
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McGuire NL, Bentley GE. Neuropeptides in the gonads: from evolution to pharmacology. Front Pharmacol 2010; 1:114. [PMID: 21607065 PMCID: PMC3095369 DOI: 10.3389/fphar.2010.00114] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 08/07/2010] [Indexed: 01/26/2023] Open
Abstract
Vertebrate gonads are the sites of synthesis and binding of many peptides that were initially classified as neuropeptides. These gonadal neuropeptide systems are neither well understood in isolation, nor in their interactions with other neuropeptide systems. Further, our knowledge of the control of these gonadal neuropeptides by peripheral hormones that bind to the gonads, and which themselves are under regulation by true neuropeptide systems from the hypothalamus, is relatively meager. This review discusses the existence of a variety of neuropeptides and their receptors which have been discovered in vertebrate gonads, and the possible way in which such systems could have evolved. We then focus on two key neuropeptides for regulation of the hypothalamo-pituitary-gonadal axis: gonadotropin-releasing hormone (GnRH) and gonadotropin-inhibitory hormone (GnIH). Comparative studies have provided us with a degree of understanding as to how a gonadal GnRH system might have evolved, and they have been responsible for the discovery of GnIH and its gonadal counterpart. We attempt to highlight what is known about these two key gonadal neuropeptides, how their actions differ from their hypothalamic counterparts, and how we might learn from comparative studies of them and other gonadal neuropeptides in terms of pharmacology, reproductive physiology and evolutionary biology.
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Affiliation(s)
- Nicolette L McGuire
- Laboratory of Reproductive Neuroendocrinology, Department of Integrative Biology, University of California at Berkeley Berkeley, CA, USA
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Zhao S, Zhu E, Yang C, Bentley GE, Tsutsui K, Kriegsfeld LJ. RFamide-related peptide and messenger ribonucleic acid expression in mammalian testis: association with the spermatogenic cycle. Endocrinology 2010; 151:617-27. [PMID: 20051487 PMCID: PMC2817627 DOI: 10.1210/en.2009-0978] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
RFamide-related peptide (RFRP), the mammalian homolog of avian gonadotropin-inhibitory hormone, has a pronounced suppressive action on the reproductive axis across species. In mammals, RFRP acts directly on GnRH neurons, and likely at the level of the pituitary, to inhibit gonadotropin secretion. In the present study, we examined whether RFRP might act outside of mammalian brain on reproductive tissues directly. Using RT-PCR and in situ hybridization, we found that both RFRP and its receptors [G protein-coupled receptor (GPR) 147 and GPR74] are expressed in the testis of Syrian hamster. These results were confirmed and extended using double- and triple-label immunohistochemistry. RFRP expression was observed in spermatocytes and in round to early elongated spermatids. Significant expression of RFRP was not seen in Leydig cells. GPR147 protein was observed in myoid cells in all stages of spermatogenesis, pachytene spermatocytes, maturation division spermatocytes, and in round and late elongated spermatids. GPR74 proteins only appeared in late elongated spermatids. Additionally, we found that RFRP and its receptor mRNA are markedly altered by day length and reproductive condition. These findings highlight a possible novel autocrine and/or paracrine role for RFRP in Syrian hamster testis, potentially contributing to the differentiation of spermatids during spermiogenesis.
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Affiliation(s)
- Sheng Zhao
- Department of Psychology and Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720-1650, USA
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Bentley GE, Ubuka T, McGuire NL, Chowdhury VS, Morita Y, Yano T, Hasunuma I, Binns M, Wingfield JC, Tsutsui K. Gonadotropin-inhibitory hormone and its receptor in the avian reproductive system. Gen Comp Endocrinol 2008; 156:34-43. [PMID: 18031743 DOI: 10.1016/j.ygcen.2007.10.003] [Citation(s) in RCA: 135] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 10/08/2007] [Accepted: 10/10/2007] [Indexed: 11/19/2022]
Abstract
Many hormones that are classified as neuropeptides are synthesized in vertebrate gonads in addition to the brain. Receptors for these hormones are also expressed in gonadal tissue; thus there is potential for a highly localized autocrine or paracrine effect of these hormones on a variety of gonadal functions. In the present study we focused on gonadotropin-inhibitory hormone (GnIH), a neuropeptide that was first discovered in the hypothalamus of birds. We present different lines of evidence for the synthesis of GnIH and its receptor in the avian reproductive system including gonads and accessory reproductive organs by studies on two orders of birds: Passeriformes and Galliformes. Binding sites for GnIH were initially identified via in vivo and in vitro receptor fluorography, and were localized in ovarian granulosa cells along with the interstitial layer and seminiferous tubules of the testis. Furthermore, species-specific primers produced clear PCR products of GnIH and GnIH receptor (GnIH-R) in songbird and quail gonadal and other reproductive tissues, such as oviduct, epididymis and vas deferens. Sequencing of the PCR products confirmed their identities. Immunocytochemistry detected GnIH peptide in ovarian thecal and granulosa cells, testicular interstitial cells and germ cells and pseudostratified columnar epithelial cells in the epididymis. In situ hybridization of GnIH-R mRNA in testes produced a strong reaction product which was localized to the germ cells and interstitium. In the epididymis, the product was also localized in the pseudostratified columnar epithelial cells. In sum, these results indicate that the avian reproductive system has the capability to synthesize and bind GnIH in several tissues. The distribution of GnIH and its receptor suggest a potential for autocrine/paracrine regulation of gonadal steroid production and germ cell differentiation and maturation.
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Affiliation(s)
- George E Bentley
- Laboratory of Reproductive Neuroendocrinology, Department of Integrative Biology and Helen Wills Neuroscience Institute, University of California at Berkeley, Berkeley, CA 94720-3140, USA.
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Abstract
In the centennial year of the birth of Hans Selye, this review compares his classical concepts of stress with a modern approach to mechanisms of CNS arousal. Relations between the two concepts are described. Neuroanatomical, neurophysiological, and functional genomic mechanisms underlying CNS arousal are briefly reviewed. Controls over stress responses and arousal are compared to particular concepts of control system engineering. Understanding these two systems is of crucial importance because their dysregulation is associated with large numbers of disease states.
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Affiliation(s)
- Donald W Pfaff
- Laboratory of Neurobiology and Behavior, The Rockefeller University, New York, NY 10021, USA.
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