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Michael OS, Kanthakumar P, Soni H, Rajesh Lenin R, Abhiram Jha K, Gangaraju R, Adebiyi A. Urotensin II system in chronic kidney disease. Curr Res Physiol 2024; 7:100126. [PMID: 38779598 PMCID: PMC11109353 DOI: 10.1016/j.crphys.2024.100126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 04/23/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Chronic kidney disease (CKD) is a progressive and long-term condition marked by a gradual decline in kidney function. CKD is prevalent among those with conditions such as diabetes mellitus, hypertension, and glomerulonephritis. Affecting over 10% of the global population, CKD stands as a significant cause of morbidity and mortality. Despite substantial advances in understanding CKD pathophysiology and management, there is still a need to explore novel mechanisms and potential therapeutic targets. Urotensin II (UII), a potent vasoactive peptide, has garnered attention for its possible role in the development and progression of CKD. The UII system consists of endogenous ligands UII and UII-related peptide (URP) and their receptor, UT. URP pathophysiology is understudied, but alterations in tissue expression levels of UII and UT and blood or urinary UII concentrations have been linked to cardiovascular and kidney dysfunctions, including systemic hypertension, chronic heart failure, glomerulonephritis, and diabetes. UII gene polymorphisms are associated with increased risk of diabetes. Pharmacological inhibition or genetic ablation of UT mitigated kidney and cardiovascular disease in rodents, making the UII system a potential target for slowing CKD progression. However, a deeper understanding of the UII system's cellular mechanisms in renal and extrarenal organs is essential for comprehending its role in CKD pathophysiology. This review explores the evolving connections between the UII system and CKD, addressing potential mechanisms, therapeutic implications, controversies, and unexplored concepts.
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Affiliation(s)
- Olugbenga S. Michael
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Praghalathan Kanthakumar
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Hitesh Soni
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Raji Rajesh Lenin
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Kumar Abhiram Jha
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Rajashekhar Gangaraju
- Department of Ophthalmology, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Adebowale Adebiyi
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO, USA
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Anesthesiology and Perioperative Medicine, University of Missouri, Columbia, MO, USA
- NextGen Precision Health, University of Missouri, Columbia, MO, USA
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Crossley DA, Burggren WW, Reiber CL, Altimiras J, Rodnick KJ. Mass Transport: Circulatory System with Emphasis on Nonendothermic Species. Compr Physiol 2016; 7:17-66. [PMID: 28134997 DOI: 10.1002/cphy.c150010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mass transport can be generally defined as movement of material matter. The circulatory system then is a biological example given its role in the movement in transporting gases, nutrients, wastes, and chemical signals. Comparative physiology has a long history of providing new insights and advancing our understanding of circulatory mass transport across a wide array of circulatory systems. Here we focus on circulatory function of nonmodel species. Invertebrates possess diverse convection systems; that at the most complex generate pressures and perform at a level comparable to vertebrates. Many invertebrates actively modulate cardiovascular function using neuronal, neurohormonal, and skeletal muscle activity. In vertebrates, our understanding of cardiac morphology, cardiomyocyte function, and contractile protein regulation by Ca2+ highlights a high degree of conservation, but differences between species exist and are coupled to variable environments and body temperatures. Key regulators of vertebrate cardiac function and systemic blood pressure include the autonomic nervous system, hormones, and ventricular filling. Further chemical factors regulating cardiovascular function include adenosine, natriuretic peptides, arginine vasotocin, endothelin 1, bradykinin, histamine, nitric oxide, and hydrogen sulfide, to name but a few. Diverse vascular morphologies and the regulation of blood flow in the coronary and cerebral circulations are also apparent in nonmammalian species. Dynamic adjustments of cardiovascular function are associated with exercise on land, flying at high altitude, prolonged dives by marine mammals, and unique morphology, such as the giraffe. Future studies should address limits of gas exchange and convective transport, the evolution of high arterial pressure across diverse taxa, and the importance of the cardiovascular system adaptations to extreme environments. © 2017 American Physiological Society. Compr Physiol 7:17-66, 2017.
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Affiliation(s)
- Dane A Crossley
- Department of Biological Sciences, University of North Texas, Denton, Texas, USA
| | - Warren W Burggren
- Department of Biological Sciences, University of North Texas, Denton, Texas, USA
| | - Carl L Reiber
- School of Life Sciences, University of Nevada Las Vegas, Las Vegas, Nevada, USA
| | - Jordi Altimiras
- AVIAN Behavioral Genomics and Physiology, IFM Biology, Linköping University, Linköping, Sweden
| | - Kenneth J Rodnick
- Department of Biological Sciences, Idaho State University, Pocatello, Idaho, USA
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Kolhatkar A, Robertson CE, Thistle ME, Gamperl AK, Currie S. Coordination of Chemical (Trimethylamine Oxide) and Molecular (Heat Shock Protein 70) Chaperone Responses to Heat Stress in Elasmobranch Red Blood Cells. Physiol Biochem Zool 2014; 87:652-62. [DOI: 10.1086/676831] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Abstract
Corticotrophin-releasing hormone (CRH) is the pivotal neuroendocrine peptide hormone associated with the regulation of the stress response in vertebrates. However, CRH-like peptides are also found in a number of invertebrate species. The origin of this peptide can be traced to a common ancestor of lineages leading to chordates and to arthropods, postulated to occur some 500 million years ago. Evidence indicates the presence of a single CRH-like receptor and a soluble binding protein system that acted to transduce and regulate the actions of the early CRH peptide. In vertebrates, genome duplications led to the divergence of CRH receptors into CRH1 and CRH2 forms in tandem with the development of four paralogous ligand lineages that included CRH; urotensin I/urocortin (Ucn), Ucn2 and Ucn3. In addition, taxon-specific genome duplications led to further local divergences in CRH ligands and receptors. Functionally, the CRH ligand-receptor system evolved initially as a molecular system to integrate early diuresis and nutrient acquisition. As multicellular organisms evolved into more complex forms, this ligand-receptor system became integrated with the organismal stress response to coordinate homoeostatic challenges with internal energy usage. In vertebrates, CRH and the CRH1 receptor became associated with the hypothalamo-pituitary-adrenal/interrenal axis and the initial stress response, whereas the CRH2 receptor was selected to play a greater role in diuresis, nutrient acquisition and the latter aspects of the stress response.
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Affiliation(s)
- David A Lovejoy
- Department of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, Canada
| | - Belinda S W Chang
- Department of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, CanadaDepartment of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, Canada
| | - Nathan R Lovejoy
- Department of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, Canada
| | - Jon del Castillo
- Department of Cell and Systems BiologyUniversity of Toronto, 25 Harbord Street, Toronto, Ontario, Canada L4A IK6Department of Ecology and EvolutionUniversity of Toronto, Toronto, Ontario, CanadaDepartment of Life SciencesUniversity of Toronto Scarborough, Toronto, Ontario, Canada
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Lovejoy DA. Structural evolution of urotensin-I: reflections of life before corticotropin releasing factor. Gen Comp Endocrinol 2009; 164:15-9. [PMID: 19393654 DOI: 10.1016/j.ygcen.2009.04.014] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2009] [Revised: 04/09/2009] [Accepted: 04/17/2009] [Indexed: 11/30/2022]
Abstract
Peptides have a long evolutionary history that predates the appearance of metazoans. The corticotropin releasing factor (CRF) family of peptides is among the most ancient peptide lineages. The identification and characterization of urotensin-I and related orthologues led the way for the elucidation of the entire CRF peptide family. A comparative analysis of the CRF paralogue sequences suggest that CRF is the most derived of these peptides and has lost many of its ancestral characteristics after it became associated with the hypothalamic-pituitary-adrenal/interrenal (HPA/I axis). In vertebrates, the urotensin-I group of orthologues, which includes sauvagine and urocortin, possess a number of shared characteristics that may be indicative of the ancestral peptide. Given the early origin of the CRF family peptides, it is likely that other peptide lineages are distantly related to the CRF family. In silico or cDNA library screening using probes based on urotensin-I/urocortin characteristics have been used to identify novel CRF family and related sequences that provide clues the evolutionary origin of the CRF family.
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Affiliation(s)
- David A Lovejoy
- Department of Cell and Systems Biology, University of Toronto, Ont., Canada.
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Takei Y, Balment RJ. Chapter 8 The Neuroendocrine Regulation of Fluid Intake and Fluid Balance. FISH PHYSIOLOGY 2009. [DOI: 10.1016/s1546-5098(09)28008-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Le Mével JC, Mimassi N, Lancien F, Mabin D, Conlon JM. Cardiovascular actions of the stress-related neurohormonal peptides, corticotropin-releasing factor and urotensin-I in the trout Oncorhynchus mykiss. Gen Comp Endocrinol 2006; 146:56-61. [PMID: 16386738 DOI: 10.1016/j.ygcen.2005.11.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2005] [Revised: 11/08/2005] [Accepted: 11/14/2005] [Indexed: 11/18/2022]
Abstract
In this review, we summarize the most significant data concerning the cardiovascular effects of centrally and peripherally administered synthetic trout corticotropin-releasing factor (CRF) and urotensin-I (U-I) in our animal model, the unanesthetized trout Oncorhynchus mykiss. Although there is more than 60% sequence identity between these two stress-related neurohormonal peptides, CRF and U-I-induced differential actions upon the mean dorsal aortic blood pressure (Pda) and the heart rate (HR) in trout maintained under similar experimental situations. After intracerebroventricular injections, only U-I induced an increase in Pda while in non-cannulated trout, CRF only decreased the HR and elevated the heart rate variability by a presumed activation of the parasympathetic nervous system activity to the heart. The CRF antagonist, the alpha-helical CRF(9-41) blocked these central actions of CRF. After intra-arterial (IA) injections, U-I induced a direct hypotensive action and an elevation in HR. This hypotensive phase was reversed to hypertension by the release of catecholamines. IA injection of CRF caused no change in Pda or HR. These cardiovascular effects are compared with the much better established actions of CRF and the orthologous urocortins in mammals.
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Affiliation(s)
- Jean-Claude Le Mével
- Laboratoire de Neurophysiologie, Laboratoire de Traitement de l'Information Médicale (LaTIM, INSERM U650), Faculté de Médecine et des Sciences de la Santé, Université de Bretagne Occidentale, Brest Cedex 3, France.
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Evans DH, Piermarini PM, Choe KP. The Multifunctional Fish Gill: Dominant Site of Gas Exchange, Osmoregulation, Acid-Base Regulation, and Excretion of Nitrogenous Waste. Physiol Rev 2005; 85:97-177. [PMID: 15618479 DOI: 10.1152/physrev.00050.2003] [Citation(s) in RCA: 1554] [Impact Index Per Article: 81.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The fish gill is a multipurpose organ that, in addition to providing for aquatic gas exchange, plays dominant roles in osmotic and ionic regulation, acid-base regulation, and excretion of nitrogenous wastes. Thus, despite the fact that all fish groups have functional kidneys, the gill epithelium is the site of many processes that are mediated by renal epithelia in terrestrial vertebrates. Indeed, many of the pathways that mediate these processes in mammalian renal epithelial are expressed in the gill, and many of the extrinsic and intrinsic modulators of these processes are also found in fish endocrine tissues and the gill itself. The basic patterns of gill physiology were outlined over a half century ago, but modern immunological and molecular techniques are bringing new insights into this complicated system. Nevertheless, substantial questions about the evolution of these mechanisms and control remain.
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Affiliation(s)
- David H Evans
- Department of Zoology, University of Florida, Gainesville 32611, USA.
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Mimassi N, Lancien F, Mabin D, Delarue C, Conlon JM, Le Mével JC. Induction of bradycardia in trout by centrally administered corticotropin-releasing-hormone (CRH). Brain Res 2003; 982:211-8. [PMID: 12915256 DOI: 10.1016/s0006-8993(03)03010-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The cardiovascular effects of centrally and peripherally administered synthetic salmon corticotropin-releasing-hormone (CRH), a member of a family of stress-related neuropeptides, were investigated in the unanesthetized trout, Oncorhynchus mykiss. In group 1, trout bearing a cannula in the dorsal aorta, neither intracerebroventricular (i.c.v.) nor intra-arterial (i.a.) injections of CRH produced any significant change in mean heart rate (HR) and mean dorsal aortic blood pressure. These results stand in contrast to the previously reported hypertensive effects of i.a. and i.c.v. injections of trout urotensin-I. In group 2, non-cannulated trout bearing two subcutaneous electrocardiographic electrodes, conditions that are considered to be less stressful to the animals, the baseline level of HR was significantly reduced compared to the corresponding value for cannulated trout. In these trout, no significant change occurred in the HR after i.c.v. administration of 1 pmol of CRH. However, i.c.v. injection of 5 pmol of CRH caused a 12% (P<0.01) decrease in HR during the 20-25 min post-injection period. In addition, the heart rate variability (HRV), a marker of vagal input to the heart, was increased by 120%. The CRH antagonist, CRH-(9-41)-peptide alone had no effect on HR or HRV but blocked CRH-induced bradycardia. In the non-cannulated trout, i.c.v. injection of trout urotensin-I (5 pmol) produced no significant change in HR and HRV. In contrast, i.c.v. administration of angiotensin II (5 pmol) elicited a highly significant 33% (P<0.001) increase in the mean HR as well as inducing a marked (64%) reduction in HRV. Our results suggest that picomolar doses of CRH act centrally to evoke a bradycardia by a probable mechanism that involves enhancement of the parasympathetic drive to the heart.
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Affiliation(s)
- Nagi Mimassi
- LaTIM (EA 2218), Institut National de la Santé et de la Recherche Médicale ERM 0102, Laboratoire de Neurophysiologie, UFR de Médecine, Université de Bretagne Occidentale, 22 Avenue Camille Desmoulins, 29285 Brest Cedex, France
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Kim JB, Holmgren S, Conlon JM. Gastrin-releasing peptides from Xenopus laevis: purification, characterization, and myotropic activity. Am J Physiol Regul Integr Comp Physiol 2001; 281:R902-8. [PMID: 11507007 DOI: 10.1152/ajpregu.2001.281.3.r902] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two molecular forms of gastrin-releasing peptide (GRP) were isolated from an extract of the intestine of the tetraploid frog Xenopus laevis. The primary structure of GRP-1 (APTSQQHTEQ(10)LSRSNINTRG(20) SHWAVGHLM.NH(2)) differs from that of GRP-2 by a single amino acid substitution (Asn(15)--> Thr(15)). GRP-(20-29) peptide (neuromedin C) was also isolated from the extract. Synthetic GRP-1 produced concentration-dependent contractions of longitudinal smooth muscle strips from Xenopus cardiac stomach (pD(2) = 8.93 +/- 0.32; n = 6). The responses were unaffected by tetrodotoxin, atropine, and methysergide, indicating a direct action of the peptide on smooth muscle cells. GRP-1 elicited concentration-dependent relaxations of precontracted (5 microM carbachol) circular smooth muscle strips from the same region (pD(2) = 8.96 +/- 0.21; n = 8). The responses were significantly (P < 0.05) attenuated (71 +/- 24% decrease in maximum response; n = 6) by indomethacin, indicating mediation, at least in part, by prostanoids. Despite the fact that Xenopus GRP-1 differs from pig GRP at 15 amino acid sites, both peptides are equipotent and equally effective for both contractile and relaxant responses, demonstrating that selective evolutionary pressure has acted to conserve the functional COOH-terminal domain in the peptide. The data suggest a physiologically important role for GRP in the regulation of gastric motility in X. laevis.
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Affiliation(s)
- J B Kim
- Regulatory Peptide Center, Department of Biomedical Sciences, Creighton University Medical School, Omaha, NE 68178-0405, USA
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Conlon JM. Singular contributions of fish neuroendocrinology to mammalian regulatory peptide research. REGULATORY PEPTIDES 2000; 93:3-12. [PMID: 11033047 DOI: 10.1016/s0167-0115(00)00172-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
During the past 20 years, several bioactive peptides have been identified in teleost fishes that subsequently have been shown to play important regulatory roles in mammalian physiology. The urophysis, corpuscles of Stannius and Brockmann body are anatomical structures particular to fish that have no obvious counterpart in mammals. Extracts and/or cDNA libraries prepared from these tissues have been used to identify for the first time urotensin II (U-II), urotensin-I (U-I), stanniocalcin and glucagon-like peptide-1 (GLP-1). Although U-II and U-I were originally regarded as exclusively the products of the teleost urophysis, the peptides have a wide phylogenetic distribution across the vertebrate lineage, including mammals. U-II is localized to motor neurones in the human spinal cord and is a potent vasoconstrictor that may be implicated in the pathogenesis of heart failure. The human ortholog of urotensin-I is urocortin which is synthesized in selected regions of the brain and is the endogenous ligand for the CRF type 2 receptor. Urocortin is believed to important in mediating the effects of stress on appetite. Stanniocalcin is involved in maintaining calcium and phosphate homeostasis in teleost fish. An ortholog of stanniocalcin has a widespread distribution in mammalian tissues and is postulated to regulate renal phosphate excretion and to protect neurons against damage during cerebral ischemia. The biological actions and therapeutic potential of GLP-1 in humans are now fully appreciated but the peptide was first identified as a domain in a preproglucagon cDNA prepared from anglerfish Brockmann bodies. In contrast to mammalian preproglucagons, GLP-1 is present in anglerfish preproglucagon as the bioactive, truncated sequence [corresponding to human GLP-1(7-37)] rather than the inactive, N-terminally extended form [corresponding to GLP-1(1-37)]. Failure to appreciate the significance of this fact retarded progress in the field for several years.
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Affiliation(s)
- J M Conlon
- Regulatory Peptide Center, Department of Biomedical Sciences, Creighton University Medical School, 68178-0405, Omaha NE, USA.
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Mimassi N, Shahbazi F, Jensen J, Mabin D, Conlon JM, Le Mével JC. Cardiovascular actions of centrally and peripherally administered trout urotensin-I in the trout. Am J Physiol Regul Integr Comp Physiol 2000; 279:R484-91. [PMID: 10938236 DOI: 10.1152/ajpregu.2000.279.2.r484] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The cardiovascular effects of centrally and peripherally administered synthetic trout urotensin (U)-I, a member of the corticotropin-releasing hormone family of neuroendocrine peptides, were investigated in unanesthetized rainbow trout Oncorhynchus mykiss. Intracerebroventricular injections of U-I (5.0 and 12.5 pmol) produced a sustained increase in mean dorsal aortic blood pressure (P(DA)) without significant change in heart rate (HR). This elevation in P(DA) was associated with an increase in cardiac output, but systemic vascular resistance did not change. Intra-arterial injection of U-I (12.5-500 pmol) evoked a dose-dependent increase in P(DA), but in contrast to the hemodynamic effects of centrally administered U-I, the hypertensive effect was associated with an increase in systemic vascular resistance and an initial fall in cardiac output. HR did not change or underwent a delayed increase. Pretreatment of trout with prazosin, an alpha-adrenoreceptor antagonist, completely abolished the rise in arterial blood pressure after intra-arterial administration of U-I, which was replaced by a sustained hypotension and tachycardia. Trout U-I produced a dose-dependent (pD(2) = 7.74 +/- 0.08) relaxation of preconstricted rings of isolated trout arterial vascular smooth muscle, suggesting that the primary action of the peptide in the periphery is vasorelaxation that is rapidly reversed by release of catecholamines. Our results suggest that U-I may regulate blood pressure in trout by acting centrally as a neurotransmitter and/or neuromodulator and peripherally as a neurohormone functioning either as a locally acting vasodilator or as a potent secretagogue of catecholamines.
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Affiliation(s)
- N Mimassi
- Laboratoire de Neurophysiologie (LATIM EA 2218), Unité de Formation et de Recherche de Médecine, Université de Bretagne Occidentale, Brest Cedex, France
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Barsyte D, Tipping DR, Smart D, Conlon JM, Baker BI, Lovejoy DA. Rainbow trout (Oncorhynchus mykiss) urotensin-I: structural differences between urotensins-I and urocortins. Gen Comp Endocrinol 1999; 115:169-77. [PMID: 10417230 DOI: 10.1006/gcen.1999.7290] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In bony fishes, both corticotropin-releasing factor (CRF) and urotensin-I play a role in the regulation of interrenal glucocorticoid release. The rainbow trout, Oncorhynchus mykiss, is a useful model for understanding the mechanisms of stress and the hypothalamo-pituitary-interrenal axis because of its phylogenetic position at the base of the euteleostei and its popularity as a food fish. Urotensin-I may act as a glucocorticoid releaser in a mechanism phylogenetically older than that of CRF. The structural and functional relationships of trout urotensin-I have been investigated. The transcript was cloned from a trout brain hypothalamic cDNA library. A single positive clone was isolated and sequenced. It possesses 3218 bases and has the longest 3' untranslated region of all urotensins-I and CRF transcripts found to date. In comparison to the other fish orthologues, it has the closest sequence identity to the mammalian urocortins. The transcript appears to be differentially processed in brain and urophysis as determined by Northern blot analysis and the presence of polyadenylation signals in the 3' untranslated region. Synthetic trout urotensin-I activated both human CRF-R1 and -R2 receptor-transfected CHO cells with a potency similar to that of white sucker (Catostomus commersoni) urotensin-I. Both fish neuropeptides possessed an order of magnitude less potency than human urocortin in CRF-R2 transfected cells.
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Affiliation(s)
- D Barsyte
- 3.614 Stopford Building, School of Biological Sciences, University of Manchester, Manchester, M13 9PT, United Kingdom
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Lovejoy DA, Balment RJ. Evolution and physiology of the corticotropin-releasing factor (CRF) family of neuropeptides in vertebrates. Gen Comp Endocrinol 1999; 115:1-22. [PMID: 10375459 DOI: 10.1006/gcen.1999.7298] [Citation(s) in RCA: 209] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Corticotropin-releasing factor (CRF), urotensin-I, urocortin and sauvagine belong to a family of related neuropeptides found throughout chordate taxa and likely stem from an ancestral peptide precursor early in metazoan ancestry. In vertebrates, current evidence suggests that CRF on one hand, and urotensin-I, urocortin and sauvagine, on the other, form paralogous lineages. Urocortin and sauvagine appear to represent tetrapod orthologues of fish urotensin-I. Sauvagine's unique structure may reflect the distinctly derived evolutionary history of the anura and the amphibia in general. The physiological actions of these peptides are mediated by at least two receptor subtypes and a soluble binding protein. Although the earliest functions of these peptides may have been associated with osmoregulation and diuresis, a constellation of physiological effects associated with stress and anxiety, vasoregulation, thermoregulation, growth and metabolism, metamorphosis and reproduction have been identified in various vertebrate species. The elaboration of neural circuitry for each of the two paralogous neuropeptide systems appears to have followed distinct pathways in the actinopterygian and sarcopterygian lineages of vertebrates. A comparision of the functional differences between these two lineages predicts additional functions of these peptides.
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Affiliation(s)
- D A Lovejoy
- School of Biological Sciences, University of Manchester, Manchester, M13 9PT, United Kingdom
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