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Leng G, Sabatier N. Oxytocin - The Sweet Hormone? Trends Endocrinol Metab 2017; 28:365-376. [PMID: 28283319 DOI: 10.1016/j.tem.2017.02.007] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 02/07/2017] [Accepted: 02/10/2017] [Indexed: 12/14/2022]
Abstract
Mammalian neurons that produce oxytocin and vasopressin apparently evolved from an ancient cell type with both sensory and neurosecretory properties that probably linked reproductive functions to energy status and feeding behavior. Oxytocin in modern mammals is an autocrine/paracrine regulator of cell function, a systemic hormone, a neuromodulator released from axon terminals within the brain, and a 'neurohormone' that acts at receptors distant from its site of release. In the periphery oxytocin is involved in electrolyte homeostasis, gastric motility, glucose homeostasis, adipogenesis, and osteogenesis, and within the brain it is involved in food reward, food choice, and satiety. Oxytocin preferentially suppresses intake of sweet-tasting carbohydrates while improving glucose tolerance and supporting bone remodeling, making it an enticing translational target.
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Affiliation(s)
- Gareth Leng
- Centre for Integrative Physiology, The University of Edinburgh, Edinburgh UK.
| | - Nancy Sabatier
- Centre for Integrative Physiology, The University of Edinburgh, Edinburgh UK
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Amri EZ, Pisani DF. Control of bone and fat mass by oxytocin. Horm Mol Biol Clin Investig 2017; 28:95-104. [PMID: 27865092 DOI: 10.1515/hmbci-2016-0045] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 10/18/2016] [Indexed: 11/15/2022]
Abstract
Osteoporosis and overweight/obesity constitute major worldwide public health burdens. Aging is associated with a decrease in hormonal secretion, lean mass and bone mass, and an increase in fat accumulation. It is established that both obesity and osteoporosis are affected by genetic and environmental factors, bone remodeling and adiposity are both regulated through the hypothalamus and sympathetic nervous system. Oxytocin (OT), belongs to the pituitary hormone family and regulates the function of peripheral target organs, its circulating levels decreased with age. Nowadays, it is well established that OT plays an important role in the control of bone and fat mass and their metabolism. Of note, OT and oxytocin receptor knock out mice develop bone defects and late-onset obesity. Thus OT emerges as a promising molecule in the treatment of osteoporosis and obesity as well as associated metabolic disorders such as type 2 diabetes and cardiovascular diseases. In this review, we will discuss findings regarding the OT effects on bone and fat mass.
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Bhosle VK, Rivera JC, Chemtob S. New insights into mechanisms of nuclear translocation of G-protein coupled receptors. Small GTPases 2017; 10:254-263. [PMID: 28125336 DOI: 10.1080/21541248.2017.1282402] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The G-protein coupled receptor (GPCR) signaling was long believed to involve activation of receptor exclusively at the cell surface, followed by its binding to heterotrimeric G-proteins and arrestins to trigger various intracellular signaling cascades, and termination of signaling by internalization of the receptor. It is now accepted that many GPCRs continue to signal after internalization in the endosomes. Since the breakthrough discoveries of nuclear binding sites for their ligands in 1980s, several GPCRs have been detected at cell nuclei. But mechanisms of nuclear localization of GPCRs, many of whom contain putative nuclear localization signals, remain poorly understood to date. Nevertheless, it is known that subcellular trafficking of GPCRs is regulated by members of Ras superfamily of small GTPases, most notably by Rab and Arf GTPases. In this commentary, we highlight several recent studies which suggest novel roles of small GTPases, importins and sorting nexin proteins in the nuclear translocation of GPCRs via vesicular transport pathways. Taken together with increasing evidence for in vivo functionality of the nuclear GPCRs, better understanding of their trafficking will provide valuable clues in cell biology.
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Affiliation(s)
- Vikrant K Bhosle
- a Department of Pharmacology and Therapeutics , McGill University , Montréal , Québec , Canada.,b CHU Sainte-Justine Hospital Research Centre , University of Montréal , Montréal , Québec , Canada.,c Maisonneuve-Rosemont Hospital Research Centre , University of Montréal , Montréal , Québec , Canada.,e Cell Biology Program , Peter Gilgan Centre for Research and Learning , Toronto , Ontario , Canada
| | - José Carlos Rivera
- b CHU Sainte-Justine Hospital Research Centre , University of Montréal , Montréal , Québec , Canada.,c Maisonneuve-Rosemont Hospital Research Centre , University of Montréal , Montréal , Québec , Canada
| | - Sylvain Chemtob
- a Department of Pharmacology and Therapeutics , McGill University , Montréal , Québec , Canada.,b CHU Sainte-Justine Hospital Research Centre , University of Montréal , Montréal , Québec , Canada.,c Maisonneuve-Rosemont Hospital Research Centre , University of Montréal , Montréal , Québec , Canada.,d Departments of Pediatrics, Ophthalmology and Pharmacology , University of Montréal , Montréal , Québec , Canada
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Bhosle VK, Rivera JC, Zhou TE, Omri S, Sanchez M, Hamel D, Zhu T, Rouget R, Rabea AA, Hou X, Lahaie I, Ribeiro-da-Silva A, Chemtob S. Nuclear localization of platelet-activating factor receptor controls retinal neovascularization. Cell Discov 2016; 2:16017. [PMID: 27462464 PMCID: PMC4941644 DOI: 10.1038/celldisc.2016.17] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/11/2016] [Indexed: 02/08/2023] Open
Abstract
Platelet-activating factor (PAF) is a pleiotropic phospholipid with proinflammatory, procoagulant and angiogenic actions on the vasculature. We and others have reported the presence of PAF receptor (Ptafr) at intracellular sites such as the nucleus. However, mechanisms of localization and physiologic functions of intracellular Ptafr remain poorly understood. We hereby identify the importance of C-terminal motif of the receptor and uncover novel roles of Rab11a GTPase and importin-5 in nuclear translocation of Ptafr in primary human retinal microvascular endothelial cells. Nuclear localization of Ptafr is independent of exogenous PAF stimulation as well as intracellular PAF biosynthesis. Moreover, nuclear Ptafr is responsible for the upregulation of unique set of growth factors, including vascular endothelial growth factor, in vitro and ex vivo. We further corroborate the intracrine PAF signaling, resulting in angiogenesis in vivo, using Ptafr antagonists with distinct plasma membrane permeability. Collectively, our findings show that nuclear Ptafr translocates in an agonist-independent manner, and distinctive functions of Ptafr based on its cellular localization point to another dimension needed for pharmacologic selectivity of drugs.
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Affiliation(s)
- Vikrant K Bhosle
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada; CHU Sainte Justine Hospital Research Centre, University of Montréal, Montréal, QC, Canada; Department of Ophthalmology, Research Centre of Hôpital Maisonneuve-Rosemont, University of Montréal, Montréal, QC, Canada
| | - José Carlos Rivera
- CHU Sainte Justine Hospital Research Centre, University of Montréal, Montréal, QC, Canada; Department of Ophthalmology, Research Centre of Hôpital Maisonneuve-Rosemont, University of Montréal, Montréal, QC, Canada
| | - Tianwei Ellen Zhou
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada; CHU Sainte Justine Hospital Research Centre, University of Montréal, Montréal, QC, Canada; Department of Ophthalmology, Research Centre of Hôpital Maisonneuve-Rosemont, University of Montréal, Montréal, QC, Canada; Department of Medicine, McGill University Health Center, Montreal, QC, Canada
| | - Samy Omri
- CHU Sainte Justine Hospital Research Centre, University of Montréal, Montréal, QC, Canada; Department of Ophthalmology, Research Centre of Hôpital Maisonneuve-Rosemont, University of Montréal, Montréal, QC, Canada
| | - Melanie Sanchez
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada; CHU Sainte Justine Hospital Research Centre, University of Montréal, Montréal, QC, Canada; Department of Ophthalmology, Research Centre of Hôpital Maisonneuve-Rosemont, University of Montréal, Montréal, QC, Canada
| | - David Hamel
- CHU Sainte Justine Hospital Research Centre, University of Montréal, Montréal, QC, Canada; Department of Pharmacology, University of Montréal, Montréal, QC, Canada
| | - Tang Zhu
- CHU Sainte Justine Hospital Research Centre, University of Montréal , Montréal, QC, Canada
| | - Raphael Rouget
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada; CHU Sainte Justine Hospital Research Centre, University of Montréal, Montréal, QC, Canada
| | - Areej Al Rabea
- Experimental Surgery, Montreal General Hospital, McGill University , Montréal, QC, Canada
| | - Xin Hou
- CHU Sainte Justine Hospital Research Centre, University of Montréal , Montréal, QC, Canada
| | - Isabelle Lahaie
- CHU Sainte Justine Hospital Research Centre, University of Montréal, Montréal, QC, Canada; Department of Ophthalmology, Research Centre of Hôpital Maisonneuve-Rosemont, University of Montréal, Montréal, QC, Canada
| | - Alfredo Ribeiro-da-Silva
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada; Alan Edwards Centre for Research on Pain, McGill University, Montréal, QC, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC, Canada
| | - Sylvain Chemtob
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC, Canada; CHU Sainte Justine Hospital Research Centre, University of Montréal, Montréal, QC, Canada; Department of Ophthalmology, Research Centre of Hôpital Maisonneuve-Rosemont, University of Montréal, Montréal, QC, Canada; Department of Pharmacology, University of Montréal, Montréal, QC, Canada; Departments of Pediatrics and Ophthalmology, Faculty of Medicine, University of Montréal, Montréal, QC, Canada
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Theofanopoulou C. Implications of Oxytocin in Human Linguistic Cognition: From Genome to Phenome. Front Neurosci 2016; 10:271. [PMID: 27378840 PMCID: PMC4906233 DOI: 10.3389/fnins.2016.00271] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 05/31/2016] [Indexed: 11/18/2022] Open
Abstract
The neurohormone oxytocin (OXT) has been found to mediate the regulation of complex socioemotional cognition in multiple ways both in humans and other animals. Recent studies have investigated the effects of OXT in different levels of analysis (from genetic to behavioral) chiefly targeting its impact on the social component and only indirectly indicating its implications in other components of our socio-interactive abilities. This article aims at shedding light onto how OXT might be modulating the multimodality that characterizes our higher-order linguistic abilities (vocal-auditory-attentional-memory-social systems). Based on evidence coming from genetic, EEG, fMRI, and behavioral studies, I attempt to establish the promises of this perspective with the goal of stressing the need for neuropeptide treatments to enter clinical practice.
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Mihailescu N, Stan G, Duta L, Chifiriuc MC, Bleotu C, Sopronyi M, Luculescu C, Oktar F, Mihailescu I. Structural, compositional, mechanical characterization and biological assessment of bovine-derived hydroxyapatite coatings reinforced with MgF 2 or MgO for implants functionalization. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 59:863-874. [DOI: 10.1016/j.msec.2015.10.078] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 09/14/2015] [Accepted: 10/26/2015] [Indexed: 01/12/2023]
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Abstract
Prior studies show that oxytocin (Oxt) and vasopressin (Avp) have opposing actions on the skeleton exerted through high-affinity G protein-coupled receptors. We explored whether Avp and Oxtr can share their receptors in the regulation of bone formation by osteoblasts. We show that the Avp receptor 1α (Avpr1α) and the Oxt receptor (Oxtr) have opposing effects on bone mass: Oxtr(-/-) mice have osteopenia, and Avpr1α(-/-) mice display a high bone mass phenotype. More notably, this high bone mass phenotype is reversed by the deletion of Oxtr in Oxtr(-/-):Avpr1α(-/-) double-mutant mice. However, although Oxtr is not indispensable for Avp action in inhibiting osteoblastogenesis and gene expression, Avp-stimulated gene expression is inhibited when the Oxtr is deleted in Avpr1α(-/-) cells. In contrast, Oxt does not interact with Avprs in vivo in a model of lactation-induced bone loss in which Oxt levels are high. Immunofluorescence microscopy of isolated nucleoplasts and Western blotting and MALDI-TOF of nuclear extracts show that Avp triggers Avpr1α localization to the nucleus. Finally, a specific Avpr2 inhibitor, tolvaptan, does not affect bone formation or bone mass, suggesting that Avpr2, which primarily functions in the kidney, does not have a significant role in bone remodeling.
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Kushwaha P, Khedgikar V, Sharma D, Yuen T, Gautam J, Ahmad N, Karvande A, Mishra PR, Trivedi PK, Sun L, Bhadada SK, Zaidi M, Trivedi R. MicroRNA 874-3p Exerts Skeletal Anabolic Effects Epigenetically during Weaning by Suppressing Hdac1 Expression. J Biol Chem 2015; 291:3959-66. [PMID: 26663087 DOI: 10.1074/jbc.m115.687152] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Indexed: 12/27/2022] Open
Abstract
Embryonic skeletogenesis and postnatal bone development require the transfer of calcium from the mother to the offspring during pregnancy and lactation. Therefore, bone resorption in the mother becomes elevated during these periods, resulting in significant maternal skeletal loss. There follows an anabolic phase around weaning during which there is a remarkable recovery of the maternal skeleton. However, the mechanism(s) of this anabolic response remain(s) largely unknown. We identified eight differentially expressed miRNAs by array profiling, of which miR-874-3p was highly expressed at weaning, a time when bone loss was noted to recover. We report that this weaning-associated miRNA is an anabolic target. Therefore, an agomir of miR-874-3p induced osteoblast differentiation and mineralization. These actions were mediated through the inhibition of Hdac1 expression and enhanced Runx2 transcriptional activation. When injected in vivo, the agomir significantly increased osteoblastogenesis and mineralization, reversed bone loss caused by ovariectomy, and increased bone strength. We speculate that elevated miR-874-3p expression during weaning enhances bone formation and that this miRNA may become a therapeutic target for conditions of bone loss.
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Affiliation(s)
- Priyanka Kushwaha
- From the Endocrinology Division, Academy of Scientific and Innovative Research, and
| | | | - Deepika Sharma
- the Council of Scientific and Industrial Research-National Botanical Research Institute, Lucknow 226001, India
| | - Tony Yuen
- the The Mount Sinai Bone Program, Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, and
| | | | | | | | - Prabhat R Mishra
- Pharmaceutics Division, Council of Scientific and Industrial Research-Central Drug Research Institute, Lucknow 226031, India
| | - Prabodh K Trivedi
- the Council of Scientific and Industrial Research-National Botanical Research Institute, Lucknow 226001, India
| | - Li Sun
- the The Mount Sinai Bone Program, Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, and
| | - Sanjay K Bhadada
- the Department of Endocrinology and Metabolism, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India
| | - Mone Zaidi
- the The Mount Sinai Bone Program, Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, and
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Leng G, Pineda R, Sabatier N, Ludwig M. 60 YEARS OF NEUROENDOCRINOLOGY: The posterior pituitary, from Geoffrey Harris to our present understanding. J Endocrinol 2015; 226:T173-85. [PMID: 25901040 DOI: 10.1530/joe-15-0087] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/15/2015] [Indexed: 01/12/2023]
Abstract
Geoffrey Harris pioneered our understanding of the posterior pituitary, mainly with experiments that involved the electrical stimulation of the supraoptico-hypophysial tract. In the present essay, we explain how his observations included clues to the pulsatile nature of the oxytocin signal - clues that were followed up by subsequent workers, including his students and their students. These studies ultimately led to our present understanding of the milk-ejection reflex and of the role of oxytocin in parturition. Discoveries of wide significance followed, including: the recognition of the importance of pulsatile hormone secretion; the recognition of the importance of stimulus-secretion coupling mechanisms in interpreting the patterned electrical activity of neurons; the physiological importance of peptide release in the brain; the recognition that peptide release comes substantially from dendrites and can be regulated independently of nerve terminal secretion; and the importance of dynamic morphological changes to neuronal function in the hypothalamus. All of these discoveries followed from the drive to understand the milk-ejection reflex. We also reflect on Harris's observations on vasopressin secretion, on the effects of stress, and on oxytocin secretion during sexual activity.
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Affiliation(s)
- Gareth Leng
- Centre for Integrative PhysiologyUniversity of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH9 8XD, UK
| | - Rafael Pineda
- Centre for Integrative PhysiologyUniversity of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH9 8XD, UK
| | - Nancy Sabatier
- Centre for Integrative PhysiologyUniversity of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH9 8XD, UK
| | - Mike Ludwig
- Centre for Integrative PhysiologyUniversity of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH9 8XD, UK
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Joyal JS, Bhosle VK, Chemtob S. Subcellular G-protein coupled receptor signaling hints at greater therapeutic selectivity. Expert Opin Ther Targets 2015; 19:717-21. [DOI: 10.1517/14728222.2015.1042365] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Elabd S, Sabry I. Two Birds with One Stone: Possible Dual-Role of Oxytocin in the Treatment of Diabetes and Osteoporosis. Front Endocrinol (Lausanne) 2015; 6:121. [PMID: 26322016 PMCID: PMC4530313 DOI: 10.3389/fendo.2015.00121] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 07/23/2015] [Indexed: 12/15/2022] Open
Abstract
Oxytocin (OT), a hormone most commonly associated with labor and lactation, may have a wide variety of physiological and pathological functions, which makes OT and its receptor potential targets for drug therapy. In this review, we highlight the newly discovered metabolic role of OT in diabetes and its complication, such as diabetic osteopathy. OT may have positive metabolic effects; this is based on the change in glucose metabolism, lipid profile, and insulin sensitivity. It may modify glucose uptake and insulin sensitivity both through direct and indirect effects. It may also cause regenerative changes in diabetic pancreatic islet cells. Moreover, it has an anabolic effect on the bone biology. So, the activation of the OT receptor pathway by infusion of OT, OT analogs, or OT agonists may represent a promising approach for the treatment of diabetes and some of its complications, including diabetic osteopathy.
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Affiliation(s)
- Seham Elabd
- Human Physiology Department, Medical Research Institute, Alexandria University, Alexandria, Egypt
- *Correspondence: Seham Elabd, Department of Human Physiology, Medical Research Institute, Alexandria University, 165, Horreya Avenue, Hadara, Alexandria, Egypt,
| | - Ismail Sabry
- Zoology Department, Faculty of Science, Alexandria University, Alexandria, Egypt
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Colaianni G, Sun L, Zaidi M, Zallone A. The "love hormone" oxytocin regulates the loss and gain of the fat-bone relationship. Front Endocrinol (Lausanne) 2015; 6:79. [PMID: 26042088 PMCID: PMC4435037 DOI: 10.3389/fendo.2015.00079] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/30/2015] [Indexed: 12/01/2022] Open
Abstract
The involvement of oxytocin (OT) in bone metabolism is an interesting area of research that recently achieved remarkable results. Moreover, several lines of evidence have largely demonstrated that OT also participates in the regulation of energy metabolism. Hence, it has recently been determined that the posterior pituitary hormone OT directly regulates bone mass: mice lacking OT or OT receptor display severe osteopenia, caused by impaired bone formation. OT administration normalizes ovariectomy-induced osteopenia, bone marrow adiposity, body weight, and intra-abdominal fat depots in mice. This effect is mediated through inhibition of adipocyte precursor differentiation and reduction of adipocyte size. The exquisite role of OT in regulating the bone-fat connection adds another milestone to the biological evidence supporting the existence of a tight relationship between the adipose tissue and the skeleton.
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Affiliation(s)
- Graziana Colaianni
- Department of Basic Medical Science, Neuroscience and Sense Organs, University of Bari, Bari, Italy
- *Correspondence: Graziana Colaianni, Section of Human Anatomy and Histology, Department of Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari, Piazza Giulio Cesare 11, Bari 70124, Italy,
| | - Li Sun
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Mone Zaidi
- Mount Sinai Bone Program, Mount Sinai School of Medicine, New York, NY, USA
| | - Alberta Zallone
- Department of Basic Medical Science, Neuroscience and Sense Organs, University of Bari, Bari, Italy
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