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Liu R, Friedrich M, Hemmen K, Jansen K, Adolfi MC, Schartl M, Heinze KG. Dimerization of melanocortin 4 receptor controls puberty onset and body size polymorphism. Front Endocrinol (Lausanne) 2023; 14:1267590. [PMID: 38027153 PMCID: PMC10667928 DOI: 10.3389/fendo.2023.1267590] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 10/24/2023] [Indexed: 12/01/2023] Open
Abstract
Xiphophorus fish exhibit a clear phenotypic polymorphism in puberty onset and reproductive strategies of males. In X. nigrensis and X. multilineatus, puberty onset is genetically determined and linked to a melanocortin 4 receptor (Mc4r) polymorphism of wild-type and mutant alleles on the sex chromosomes. We hypothesized that Mc4r mutant alleles act on wild-type alleles by a dominant negative effect through receptor dimerization, leading to differential intracellular signaling and effector gene activation. Depending on signaling strength, the onset of puberty either occurs early or is delayed. Here, we show by Förster Resonance Energy Transfer (FRET) that wild-type Xiphophorus Mc4r monomers can form homodimers, but also heterodimers with mutant receptors resulting in compromised signaling which explains the reduced Mc4r signaling in large males. Thus, hetero- vs. homo- dimerization seems to be the key molecular mechanism for the polymorphism in puberty onset and body size in male fish.
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Affiliation(s)
- Ruiqi Liu
- Molecular Microscopy, Rudolf Virchow Center for Integrative and Translation Bioimaging, Julius-Maximilians-Universität Würzburg (JMU), Wuerzburg, Germany
- Developmental Biochemistry, Biocenter, Julius-Maximilians-Universität Würzburg (JMU), Wuerzburg, Germany
| | - Mike Friedrich
- Molecular Microscopy, Rudolf Virchow Center for Integrative and Translation Bioimaging, Julius-Maximilians-Universität Würzburg (JMU), Wuerzburg, Germany
| | - Katherina Hemmen
- Molecular Microscopy, Rudolf Virchow Center for Integrative and Translation Bioimaging, Julius-Maximilians-Universität Würzburg (JMU), Wuerzburg, Germany
| | - Kerstin Jansen
- Molecular Microscopy, Rudolf Virchow Center for Integrative and Translation Bioimaging, Julius-Maximilians-Universität Würzburg (JMU), Wuerzburg, Germany
| | - Mateus C. Adolfi
- Developmental Biochemistry, Biocenter, Julius-Maximilians-Universität Würzburg (JMU), Wuerzburg, Germany
| | - Manfred Schartl
- Developmental Biochemistry, Biocenter, Julius-Maximilians-Universität Würzburg (JMU), Wuerzburg, Germany
- The Xiphophorus Genetic Stock Center, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, United States
| | - Katrin G. Heinze
- Molecular Microscopy, Rudolf Virchow Center for Integrative and Translation Bioimaging, Julius-Maximilians-Universität Würzburg (JMU), Wuerzburg, Germany
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Reinoß P, Ciglieri E, Minére M, Bremser S, Klein A, Löhr H, Fuller PM, Büschges A, Kloppenburg P, Fenselau H, Hammerschmidt M. Hypothalamic Pomc Neurons Innervate the Spinal Cord and Modulate the Excitability of Premotor Circuits. Curr Biol 2020; 30:4579-4593.e7. [PMID: 32976803 DOI: 10.1016/j.cub.2020.08.103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 07/30/2020] [Accepted: 08/27/2020] [Indexed: 12/20/2022]
Abstract
Locomotion requires energy, yet animals need to increase locomotion in order to find and consume food in energy-deprived states. While such energy homeostatic coordination suggests brain origin, whether the central melanocortin 4 receptor (Mc4r) system directly modulates locomotion through motor circuits is unknown. Here, we report that hypothalamic Pomc neurons in zebrafish and mice have long-range projections into spinal cord regions harboring Mc4r-expressing V2a interneurons, crucial components of the premotor networks. Furthermore, in zebrafish, Mc4r activation decreases the excitability of spinal V2a neurons as well as swimming and foraging, while systemic or V2a neuron-specific blockage of Mc4r promotes locomotion. In contrast, in mice, electrophysiological recordings revealed that two-thirds of V2a neurons in lamina X are excited by the Mc4r agonist α-MSH, and acute inhibition of Mc4r signaling reduces locomotor activity. In addition, we found other Mc4r neurons in spinal lamina X that are inhibited by α-MSH, which is in line with previous studies in rodents where Mc4r agonists reduced locomotor activity. Collectively, our studies identify spinal V2a interneurons as evolutionary conserved second-order neurons of the central Mc4r system, providing a direct anatomical and functional link between energy homeostasis and locomotor control systems. The net effects of this modulatory system on locomotor activity can vary between different vertebrate species and, possibly, even within one species. We discuss the biological sense of this phenomenon in light of the ambiguity of locomotion on energy balance and the different living conditions of the different species.
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Liu R, Du K, Ormanns J, Adolfi MC, Schartl M. Melanocortin 4 receptor signaling and puberty onset regulation in Xiphophorus swordtails. Gen Comp Endocrinol 2020; 295:113521. [PMID: 32470471 DOI: 10.1016/j.ygcen.2020.113521] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/15/2020] [Accepted: 05/22/2020] [Indexed: 01/01/2023]
Abstract
Fish of the genus Xiphophorus provide a prominent example of genetic control of male body size and reproductive tactics. In X.nigrensis and X.multilineatus, puberty onset and body length are determined by melanocortin 4 receptor (Mc4r) allelic and copy number variations which were proposed to fine-tune the signaling output of the system. Accessory protein Mrap2 is required for growth across species by affecting Mc4r signaling. The molecular mechanism how Mc4r signaling controls puberty regulation in Xiphophorus and whether the interaction with Mrap2 is also involved was so far unclear. Hence, we examined Mc4r and Mrap2 in X.nigrensis and X.multilineatus, in comparison to a more distantly related species, X.hellerii. mc4r and mrap2 transcripts co-localized in the hypothalamus and preoptic regions in large males, small males and females of X.nigrensis, with similar signal strength for mrap2 but higher expression of mc4r in large males. This overexpression is constituted by wild-type and one subtype of mutant alleles. In vitro studies revealed that Mrap2 co-expressed with Mc4r increased cAMP production but did not change EC50. Cells co-expressing the wild-type and one mutant allele showed lower cAMP signaling than Mc4r wild-type cells. This indicates a role of Mc4r alleles, but not Mrap2, in puberty signaling. Different from X.nigrensis and X.multilineatus, X.hellerii has only wild-type alleles, but also shows a puberty onset and body length polymorphism, despite the absence of mutant alleles. Like in the two other species, mc4r and mrap2 transcripts colocalized and mc4r is expressed at substantially higher levels in large males. This demonstrates that puberty and growth regulation mechanism may not be identical even within same genus.
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MESH Headings
- Adaptor Proteins, Signal Transducing/metabolism
- Alleles
- Amino Acid Sequence
- Animals
- Cyprinodontiformes/genetics
- Cyprinodontiformes/metabolism
- DNA Copy Number Variations/genetics
- Female
- Gene Expression Regulation, Developmental
- Male
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, Melanocortin, Type 4/chemistry
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Sexual Maturation/physiology
- Signal Transduction
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Affiliation(s)
- Ruiqi Liu
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Kang Du
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany; Developmental Biochemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Jenny Ormanns
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Mateus C Adolfi
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany; Developmental Biochemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Manfred Schartl
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany; Developmental Biochemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany; The Xiphophorus Genetic Stock Center, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA.
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Liu R, Kinoshita M, Adolfi MC, Schartl M. Analysis of the Role of the Mc4r System in Development, Growth, and Puberty of Medaka. Front Endocrinol (Lausanne) 2019; 10:213. [PMID: 31024451 PMCID: PMC6463759 DOI: 10.3389/fendo.2019.00213] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/18/2019] [Indexed: 01/23/2023] Open
Abstract
In mammals the melanocortin 4 receptor (Mc4r) signaling system has been mainly associated with the regulation of appetite and energy homeostasis. In fish of the genus Xiphophorus (platyfish and swordtails) puberty onset is genetically determined by a single locus, which encodes the mc4r. Wild populations of Xiphophorus are polymorphic for early and late-maturing individuals. Copy number variation of different mc4r alleles is responsible for the difference in puberty onset. To answer whether this is a special adaptation of the Mc4r signaling system in the lineage of Xiphophorus or a more widely conserved mechanism in teleosts, we studied the role of Mc4r in reproductive biology of medaka (Oryzias latipes), a close relative to Xiphophorus and a well-established model to study gonadal development. To understand the potential role of Mc4r in medaka, we characterized the major features of the Mc4r signaling system (mc4r, mrap2, pomc, agrp1). In medaka, all these genes are expressed before hatching. In adults, they are mainly expressed in the brain. The transcript of the receptor accessory protein mrap2 co-localizes with mc4r in the hypothalamus in adult brains indicating a conserved function of modulating Mc4r signaling. Comparing growth and puberty between wild-type and mc4r knockout medaka revealed that absence of Mc4r does not change puberty timing but significantly delays hatching. Embryonic development of knockout animals is retarded compared to wild-types. In conclusion, the Mc4r system in medaka is involved in regulation of growth rather than puberty.
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Affiliation(s)
- Ruiqi Liu
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Masato Kinoshita
- Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Mateus C Adolfi
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Manfred Schartl
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
- Comprehensive Cancer Center Mainfranken, University Clinic Wuerzburg, Wuerzburg, Germany
- Hagler Institute for Advanced Study and Department of Biology, Texas A&M University, College Station, TX, United States
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Zhang M, Chen Y, Xu H, Yang L, Yuan F, Li L, Xu Y, Chen Y, Zhang C, Lin G. Melanocortin Receptor 4 Signaling Regulates Vertebrate Limb Regeneration. Dev Cell 2018; 46:397-409.e5. [PMID: 30130530 PMCID: PMC6107305 DOI: 10.1016/j.devcel.2018.07.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 05/28/2018] [Accepted: 07/21/2018] [Indexed: 11/16/2022]
Abstract
Melanocortin 4 receptor (Mc4r) plays a crucial role in the central control of energy homeostasis, but its role in peripheral organs has not been fully explored. We have investigated the roles of hypothalamus-mediated energy metabolism during Xenopus limb regeneration. We report that hypothalamus injury inhibits Xenopus tadpole limb regeneration. By loss-of-function and gain-of-function studies, we show that Mc4r signaling is required for limb regeneration in regeneration-competent tadpoles and stimulates limb regeneration in later-stage regeneration-defective tadpoles. It regulates limb regeneration through modulating energy homeostasis and ROS production. Even more interestingly, our results demonstrate that Mc4r signaling is regulated by innervation and α-MSH substitutes for the effect of nerves in limb regeneration. Mc4r signaling is also required for mouse digit regeneration. Thus, our findings link vertebrate limb regeneration with Mc4r-mediated energy homeostasis and provide a new avenue for understanding Mc4r signaling in the peripheral organs.
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Affiliation(s)
- Mengshi Zhang
- Research Center for Translational Medicine, Translational Medical Center for Stem Cell Therapy, and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China
| | - Youwei Chen
- Research Center for Translational Medicine, Translational Medical Center for Stem Cell Therapy, and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China
| | - Hanqian Xu
- Research Center for Translational Medicine, Translational Medical Center for Stem Cell Therapy, and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China; Stem Cell Institute, Department of Genetics Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA
| | - Li Yang
- Research Center for Translational Medicine, Translational Medical Center for Stem Cell Therapy, and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China
| | - Feng Yuan
- Research Center for Translational Medicine, Translational Medical Center for Stem Cell Therapy, and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China
| | - Lei Li
- Research Center for Translational Medicine, Translational Medical Center for Stem Cell Therapy, and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China
| | - Ying Xu
- Research Center for Translational Medicine, Translational Medical Center for Stem Cell Therapy, and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China
| | - Ying Chen
- Stem Cell Institute, Department of Genetics Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Chao Zhang
- Research Center for Translational Medicine, Translational Medical Center for Stem Cell Therapy, and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China.
| | - Gufa Lin
- Research Center for Translational Medicine, Translational Medical Center for Stem Cell Therapy, and Institute for Regenerative Medicine, Shanghai East Hospital, Shanghai Key Laboratory of Signaling and Disease Research, School of Life Sciences and Technology, Tongji University, Shanghai 200120, China; Stem Cell Institute, Department of Genetics Cell Biology and Development, University of Minnesota, Minneapolis, MN 55455, USA.
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Clemmensen C, Finan B, Fischer K, Tom RZ, Legutko B, Sehrer L, Heine D, Grassl N, Meyer CW, Henderson B, Hofmann SM, Tschöp MH, Van der Ploeg LHT, Müller TD. Dual melanocortin-4 receptor and GLP-1 receptor agonism amplifies metabolic benefits in diet-induced obese mice. EMBO Mol Med 2015; 7:288-98. [PMID: 25652173 PMCID: PMC4364946 DOI: 10.15252/emmm.201404508] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
We assessed the efficacy of simultaneous agonism at the glucagon-like peptide-1 receptor (GLP-1R) and the melanocortin-4 receptor (MC4R) for the treatment of obesity and diabetes in rodents. Diet-induced obese (DIO) mice were chronically treated with either the long-acting GLP-1R agonist liraglutide, the MC4R agonist RM-493 or a combination of RM-493 and liraglutide. Co-treatment of DIO mice with RM-493 and liraglutide improves body weight loss and enhances glycemic control and cholesterol metabolism beyond what can be achieved with either mono-therapy. The superior metabolic efficacy of this combination therapy is attributed to the anorectic and glycemic actions of both drugs, along with the ability of RM-493 to increase energy expenditure. Interestingly, compared to mice treated with liraglutide alone, hypothalamic Glp-1r expression was higher in mice treated with the combination therapy after both acute and chronic treatment. Further, RM-493 enhanced hypothalamic Mc4r expression. Hence, co-dosing with MC4R and GLP-1R agonists increases expression of each receptor, indicative of minimized receptor desensitization. Together, these findings suggest potential opportunities for employing combination treatments that comprise parallel MC4R and GLP-1R agonism for the treatment of obesity and diabetes.
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Affiliation(s)
- Christoffer Clemmensen
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Brian Finan
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Katrin Fischer
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Robby Zachariah Tom
- Institute for Diabetes and Regeneration Research & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Beata Legutko
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Laura Sehrer
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Daniela Heine
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Niklas Grassl
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | - Carola W Meyer
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | | | - Susanna M Hofmann
- Institute for Diabetes and Regeneration Research & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Matthias H Tschöp
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
| | | | - Timo D Müller
- Institute for Diabetes and Obesity & Helmholtz Diabetes Center, Helmholtz Zentrum München German Research Center for Environmental Health (GmbH), Neuherberg, Germany Division of Metabolic Diseases, Department of Medicine, Technische Universität München, Munich, Germany
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