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Yuan XC, Tao YX. Ligands for Melanocortin Receptors: Beyond Melanocyte-Stimulating Hormones and Adrenocorticotropin. Biomolecules 2022; 12:biom12101407. [PMID: 36291616 PMCID: PMC9599618 DOI: 10.3390/biom12101407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 11/16/2022] Open
Abstract
The discovery of melanocortins in 1916 has resulted in more than 100 years of research focused on these peptides. Extensive studies have elucidated well-established functions of melanocortins mediated by cell surface receptors, including MSHR (melanocyte-stimulating hormone receptor) and ACTHR (adrenocorticotropin receptor). Subsequently, three additional melanocortin receptors (MCRs) were identified. Among these five MCRs, MC3R and MC4R are expressed primarily in the central nervous system, and are therefore referred to as the neural MCRs. Since the central melanocortin system plays important roles in regulating energy homeostasis, targeting neural MCRs is emerging as a therapeutic approach for treating metabolic conditions such as obesity and cachexia. Early efforts modifying endogenous ligands resulted in the development of many potent and selective ligands. This review focuses on the ligands for neural MCRs, including classical ligands (MSH and agouti-related peptide), nonclassical ligands (lipocalin 2, β-defensin, small molecules, and pharmacoperones), and clinically approved ligands (ACTH, setmelanotide, bremelanotide, and several repurposed drugs).
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Affiliation(s)
- Xiao-Chen Yuan
- College of Animal Science and Technology, Anhui Agricultural University, Hefei 230061, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA
- Correspondence:
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2
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Liu Z, Hruby VJ. MC4R biased signalling and the conformational basis of biological function selections. J Cell Mol Med 2022; 26:4125-4136. [PMID: 35818295 PMCID: PMC9344818 DOI: 10.1111/jcmm.17441] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 05/26/2022] [Accepted: 06/01/2022] [Indexed: 11/30/2022] Open
Abstract
The MC4R, a GPCR, has long been a major target for obesity treatment. As the most well‐studied melanocortin receptor subtype, the evolutionary knowledge pushes the drug development and structure–activity relationship (SAR) moving forward. The past decades have witnessed the evolution of scientists' view on GPCRs gradually from the control of a single canonical signalling pathway via a bilateral ‘active‐inactive’ model to a multi‐state alternative model where the ligands' binding affects the selection of the downstream signalling. This evolution brings the concept of biased signalling and the beginning of the next generation of peptide drug development, with the aim of turning from receptor subtype specificity to signalling pathway selectivity. The determination of the value structures of the MC4R revealed insights into the working mechanism of MC4R activation upon binding of agonists. However, new challenge has risen as we seek to unravel the mystery of MC4R signalling selection. Thus, more biased agonists and ligands with representative biological functions are needed to solve the rest of the puzzle.
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Affiliation(s)
- Zekun Liu
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona, USA
| | - Victor J Hruby
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona, USA
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3
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Nimbi FM, Simonelli C. The Sex Therapists' Approach to the Evaluation and Management of Low Sex Drive in Men. J Sex Med 2022; 19:546-552. [DOI: 10.1016/j.jsxm.2022.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 01/28/2022] [Accepted: 02/02/2022] [Indexed: 11/26/2022]
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4
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Yeo GSH, Chao DHM, Siegert AM, Koerperich ZM, Ericson MD, Simonds SE, Larson CM, Luquet S, Clarke I, Sharma S, Clément K, Cowley MA, Haskell-Luevano C, Van Der Ploeg L, Adan RAH. The melanocortin pathway and energy homeostasis: From discovery to obesity therapy. Mol Metab 2021; 48:101206. [PMID: 33684608 PMCID: PMC8050006 DOI: 10.1016/j.molmet.2021.101206] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 02/28/2021] [Accepted: 03/03/2021] [Indexed: 02/08/2023] Open
Abstract
Background Over the past 20 years, insights from human and mouse genetics have illuminated the central role of the brain leptin-melanocortin pathway in controlling mammalian food intake, with genetic disruption resulting in extreme obesity, and more subtle polymorphic variations influencing the population distribution of body weight. At the end of 2020, the U.S. Food and Drug Administration (FDA) approved setmelanotide, a melanocortin 4 receptor agonist, for use in individuals with severe obesity due to either pro-opiomelanocortin (POMC), proprotein convertase subtilisin/kexin type 1 (PCSK1), or leptin receptor (LEPR) deficiency. Scope of review Herein, we chart the melanocortin pathway's history, explore its pharmacology, genetics, and physiology, and describe how a neuropeptidergic circuit became an important druggable obesity target. Major conclusions Unravelling the genetics of the subset of severe obesity has revealed the importance of the melanocortin pathway in appetitive control; coupling this with studying the molecular pharmacology of compounds that bind melanocortin receptors has brought a new obesity drug to the market. This process provides a drug discovery template for complex disorders, which for setmelanotide took 25 years to transform from a single gene into an approved drug.
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Affiliation(s)
- Giles S H Yeo
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | | | - Anna-Maria Siegert
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, UK.
| | - Zoe M Koerperich
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Mark D Ericson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Stephanie E Simonds
- Metabolism, Diabetes, and Obesity Programme, Monash Biomedicine Discovery Institute, and Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | - Courtney M Larson
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | - Serge Luquet
- Université de Paris, BFA, UMR 8251, CNRS, Paris, France.
| | - Iain Clarke
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC 3010, Australia.
| | | | - Karine Clément
- Assistance Publique Hôpitaux de Paris, Nutrition Department, Pitié-Salpêtrière Hospital, Paris, France, Sorbonne Université, INSERM, Nutrition and Obesity: Systemic Approaches (NutriOmics) Research Unit, Paris, France.
| | - Michael A Cowley
- Metabolism, Diabetes, and Obesity Programme, Monash Biomedicine Discovery Institute, and Department of Physiology, Monash University, Clayton, Victoria, Australia.
| | - Carrie Haskell-Luevano
- Department of Medicinal Chemistry and Institute for Translational Neuroscience, University of Minnesota, Minneapolis, MN, USA 55455.
| | | | - Roger A H Adan
- Department of Translational Neuroscience, UMCU Brain Centre, University Medical Centre Utrecht, Utrecht University, the Netherlands; Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Sweden.
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Dinparastisaleh R, Mirsaeidi M. Antifibrotic and Anti-Inflammatory Actions of α-Melanocytic Hormone: New Roles for an Old Player. Pharmaceuticals (Basel) 2021; 14:ph14010045. [PMID: 33430064 PMCID: PMC7827684 DOI: 10.3390/ph14010045] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 01/04/2021] [Accepted: 01/06/2021] [Indexed: 12/16/2022] Open
Abstract
The melanocortin system encompasses melanocortin peptides, five receptors, and two endogenous antagonists. Besides pigmentary effects generated by α-Melanocytic Hormone (α-MSH), new physiologic roles in sexual activity, exocrine secretion, energy homeostasis, as well as immunomodulatory actions, exerted by melanocortins, have been described recently. Among the most common and burdensome consequences of chronic inflammation is the development of fibrosis. Depending on the regenerative capacity of the affected tissue and the quality of the inflammatory response, the outcome is not always perfect, with the development of some fibrosis. Despite the heterogeneous etiology and clinical presentations, fibrosis in many pathological states follows the same path of activation or migration of fibroblasts, and the differentiation of fibroblasts to myofibroblasts, which produce collagen and α-SMA in fibrosing tissue. The melanocortin agonists might have favorable effects on the trajectories leading from tissue injury to inflammation, from inflammation to fibrosis, and from fibrosis to organ dysfunction. In this review we briefly summarized the data on structure, receptor signaling, and anti-inflammatory and anti-fibrotic properties of α-MSH and proposed that α-MSH analogues might be promising future therapeutic candidates for inflammatory and fibrotic diseases, regarding their favorable safety profile.
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Affiliation(s)
- Roshan Dinparastisaleh
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, MD 21218, USA;
| | - Mehdi Mirsaeidi
- Division of Pulmonary and Critical Care, University of Miami, Miami, FL 33146, USA
- Correspondence: ; Tel.: +1-305-243-1377
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6
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Genetics and erectile dysfunction: leveraging early foundations for new discoveries. Int J Impot Res 2020; 34:252-259. [PMID: 33173200 DOI: 10.1038/s41443-020-00372-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 09/29/2020] [Accepted: 10/29/2020] [Indexed: 11/08/2022]
Abstract
There is considerable interest in understanding the genetics of erectile dysfunction (ED). Since early twin studies that suggested a genetic component to ED, multiple candidate gene studies have identified genetic variants that may be associated with ED. Genome-wide association studies (GWAS) have overcome some of the criticism of the candidate gene approach. Two recent GWAS studies have identified loci near SIM1 that may be associated with ED and have renewed interest in the leptin melanocortin signaling pathway. We review the current literature on the genetic basis of ED by highlighting several candidate genes and genetic variants associated with ED.
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Kim S, Cho MC, Cho SY, Chung H, Rajasekaran MR. Novel Emerging Therapies for Erectile Dysfunction. World J Mens Health 2020; 39:48-64. [PMID: 32202086 PMCID: PMC7752520 DOI: 10.5534/wjmh.200007] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 01/27/2020] [Indexed: 12/19/2022] Open
Abstract
Currently, several treatments exist for the improvement of erectile dysfunction (ED). These include medical therapies such as phosphodiesterase type 5 inhibitors (PDE5-Is), invasive methods such as intracavernosal injection therapy of vaso-active substances, vacuum erection devices, and penile prosthesis implants. However, the percentage of patients that are unresponsive to available treatments and who drop out from treatments remains high. Current evidence reveals that the pathogenesis of ED is related to multiple factors including underlying comorbidities, previous surgery, and psychological factors. Diverse approaches using novel molecular pathways or new technologies have been tested as potential therapeutic options for difficultto-treat ED populations. Melanocortin receptor agonist, a centrally acting agent, showed promising results by initiating erection without sexual stimulation in non-responders to PDE5-Is. Recent clinical and pre-clinical studies using human tissues suggested that new peripherally acting agents including the Max-K channel activator, guanylate cyclase activator, and nitric oxide donor could be potential therapies either as a monotherapy or in combination with PDE5-Is in ED patients. According to several clinical trials, regeneration therapy using stem cells showed favorable data in men with diabetic or post-prostatectomy ED. Low-intensity shock wave therapy also demonstrated promising results in patients with vasculogenic ED. There are growing evidences which suggest the efficacy of these emerging therapies, though most of the therapies still need to be validated by well-designed clinical trials. It is expected that, should their long-term safety and efficacy be proven, the emerging treatments can meet the needs of patients hitherto unresponsive to or unsatisfied by current therapies for ED.
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Affiliation(s)
- Soyeun Kim
- Department of Family Medicine, Korea Cancer Center Hospital, Seoul, Korea
| | - Min Chul Cho
- Department of Urology, SMG-SNU Boramae Medical Center, Seoul, Korea
| | - Sung Yong Cho
- Department of Urology, Inje University Ilsan Paik Hospital, Goyang, Korea
| | - Hong Chung
- Department of Urology, Konkuk University School of Medicine, Chungju, Korea
| | - Mahadevan Raj Rajasekaran
- Department of Urology, San Diego VA Health Care System & University of California, San Diego, CA, USA.
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Semple E, Shalabi F, Hill JW. Oxytocin Neurons Enable Melanocortin Regulation of Male Sexual Function in Mice. Mol Neurobiol 2019; 56:6310-6323. [PMID: 30756300 PMCID: PMC6684847 DOI: 10.1007/s12035-019-1514-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 01/28/2019] [Indexed: 12/13/2022]
Abstract
The melanocortin pathway has been implicated in both metabolism and sexual function. When the melanocortin 4 receptor (MC4R) is knocked out globally, male mice display obesity, low sexual desire, and copulatory difficulties; however, it is unclear whether these phenotypes are interdependent. To elucidate the neuronal circuitry involved in sexual dysfunction in MC4R knockouts, we re-expressed the MC4R in these mice exclusively on Sim1 neurons (tbMC4RSim1 mice) or on a subset of Sim1 neurons, namely oxytocin neurons (tbMC4Roxt mice). The groups were matched at young ages to control for the effects of obesity. Interestingly, young MC4R null mice had no deficits in sexual motivation or erectile function. However, MC4R null mice were found to have an increased latency to reach ejaculation compared to control mice, which was restored in both tbMC4RSim1 and tbMC4Roxt mice. These results indicate that melanocortin signaling via the MC4R on oxytocin neurons is important for normal ejaculation independent of the male's metabolic health.
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Affiliation(s)
- Erin Semple
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Ave., Toledo, OH, 43614, USA
| | - Firas Shalabi
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Ave., Toledo, OH, 43614, USA
| | - Jennifer W Hill
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, 3000 Arlington Ave., Toledo, OH, 43614, USA.
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Duque-Díaz E, Alvarez-Ojeda O, Coveñas R. Enkephalins and ACTH in the mammalian nervous system. VITAMINS AND HORMONES 2019; 111:147-193. [PMID: 31421699 DOI: 10.1016/bs.vh.2019.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The pentapeptides methionine-enkephalin and leucine-enkephalin belong to the opioid family of peptides, and the non-opiate peptide adrenocorticotropin hormone (ACTH) to the melanocortin peptide family. Enkephalins/ACTH are derived from pro-enkephalin, pro-dynorphin or pro-opiomelanocortin precursors and, via opioid and melanocortin receptors, are responsible for many biological activities. Enkephalins exhibit the highest affinity for the δ receptor, followed by the μ and κ receptors, whereas ACTH binds to the five subtypes of melanocortin receptor, and is the only member of the melanocortin family of peptides that binds to the melanocortin-receptor 2 (ACTH receptor). Enkephalins/ACTH and their receptors exhibit a widespread anatomical distribution. Enkephalins are involved in analgesia, angiogenesis, blood pressure, embryonic development, emotional behavior, feeding, hypoxia, limbic system modulation, neuroprotection, peristalsis, and wound repair; as well as in hepatoprotective, motor, neuroendocrine and respiratory mechanisms. ACTH plays a role in acetylcholine release, aggressive behavior, blood pressure, bone maintenance, hyperalgesia, feeding, fever, grooming, learning, lipolysis, memory, nerve injury repair, neuroprotection, sexual behavior, sleep, social behavior, tissue growth and stimulates the synthesis and secretion of glucocorticoids. Enkephalins/ACTH are also involved in many pathologies. Enkephalins are implicated in alcoholism, cancer, colitis, depression, heart failure, Huntington's disease, influenza A virus infection, ischemia, multiple sclerosis, and stress. ACTH plays a role in Addison's disease, alcoholism, cancer, Cushing's disease, dermatitis, encephalitis, epilepsy, Graves' disease, Guillain-Barré syndrome, multiple sclerosis, podocytopathies, and stress. In this review, we provide an updated description of the enkephalinergic and ACTH systems.
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Affiliation(s)
- Ewing Duque-Díaz
- Universidad de Santander UDES, Laboratory of Neurosciences, School of Medicine, Bucaramanga, Colombia.
| | - Olga Alvarez-Ojeda
- Universidad Industrial de Santander, Department of Pathology, School of Medicine, Bucaramanga, Colombia
| | - Rafael Coveñas
- Laboratory of Neuroanatomy of the Peptidergic Systems, Institute of Neurosciences of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
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10
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Hill JW, Elias CF. Neuroanatomical Framework of the Metabolic Control of Reproduction. Physiol Rev 2019; 98:2349-2380. [PMID: 30109817 DOI: 10.1152/physrev.00033.2017] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
A minimum amount of energy is required for basic physiological processes, such as protein biosynthesis, thermoregulation, locomotion, cardiovascular function, and digestion. However, for reproductive function and survival of the species, extra energy stores are necessary. Production of sex hormones and gametes, pubertal development, pregnancy, lactation, and parental care all require energy reserves. Thus the physiological systems that control energy homeostasis and reproductive function coevolved in mammals to support both individual health and species subsistence. In this review, we aim to gather scientific knowledge produced by laboratories around the world on the role of the brain in integrating metabolism and reproduction. We describe essential neuronal networks, highlighting key nodes and potential downstream targets. Novel animal models and genetic tools have produced substantial advances, but critical gaps remain. In times of soaring worldwide obesity and metabolic dysfunction, understanding the mechanisms by which metabolic stress alters reproductive physiology has become crucial for human health.
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Affiliation(s)
- Jennifer W Hill
- Center for Diabetes and Endocrine Research, Departments of Physiology and Pharmacology and of Obstetrics and Gynecology, University of Toledo College of Medicine , Toledo, Ohio ; and Departments of Molecular and Integrative Physiology and of Obstetrics and Gynecology, University of Michigan , Ann Arbor, Michigan
| | - Carol F Elias
- Center for Diabetes and Endocrine Research, Departments of Physiology and Pharmacology and of Obstetrics and Gynecology, University of Toledo College of Medicine , Toledo, Ohio ; and Departments of Molecular and Integrative Physiology and of Obstetrics and Gynecology, University of Michigan , Ann Arbor, Michigan
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11
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Wang W, Guo DY, Lin YJ, Tao YX. Melanocortin Regulation of Inflammation. Front Endocrinol (Lausanne) 2019; 10:683. [PMID: 31649620 PMCID: PMC6794349 DOI: 10.3389/fendo.2019.00683] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/19/2019] [Indexed: 12/18/2022] Open
Abstract
Adrenocorticotropic hormone (ACTH), and α-, β-, and γ-melanocyte-stimulating hormones (α-, β-, γ-MSH), collectively known as melanocortins, together with their receptors (melanocortin receptors), are components of an ancient modulatory system. The clinical use of ACTH in the treatment of rheumatoid arthritis started in 1949, originally thought that the anti-inflammatory action was through hypothalamus-pituitary-adrenal axis and glucocorticoid-dependent. Subsequent decades have witnessed extensive attempts in unraveling the physiology and pharmacology of the melanocortin system. It is now known that ACTH, together with α-, β-, and γ-MSHs, also possess glucocorticoid-independent anti-inflammatory and immunomodulatory effects by activating the melanocortin receptors expressed in the brain or peripheral immune cells. This review will briefly introduce the melanocortin system and highlight the action of melanocortins in the regulation of immune functions from in vitro, in vivo, preclinical, and clinical studies. The potential therapeutic use of melanocortins are also summarized.
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Affiliation(s)
- Wei Wang
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
| | - Dong-Yu Guo
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
- *Correspondence: Dong-Yu Guo
| | - Yue-Jun Lin
- Department of Clinical Laboratory, Xiamen Huli Guoyu Clinic, Co., Ltd., Xiamen, China
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology, and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States
- Ya-Xiong Tao
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Abstract
Erectile dysfunction is a common condition of men in middle and older ages. Twin studies suggest that about one-third of the risk is due to genetic factors, independent of other known erectile dysfunction risk factors. However, studies that have searched for specific genetic contributors have been limited due to small sample sizes, candidate gene approaches, and weak phenotyping. As a result, there are no confirmed genetic risk factors for erectile dysfunction. This study finds a specific genetic cause for erectile dysfunction. Erectile dysfunction affects millions of men worldwide. Twin studies support the role of genetic risk factors underlying erectile dysfunction, but no specific genetic variants have been identified. We conducted a large-scale genome-wide association study of erectile dysfunction in 36,649 men in the multiethnic Kaiser Permanente Northern California Genetic Epidemiology Research in Adult Health and Aging cohort. We also undertook replication analyses in 222,358 men from the UK Biobank. In the discovery cohort, we identified a single locus (rs17185536-T) on chromosome 6 near the single-minded family basic helix-loop-helix transcription factor 1 (SIM1) gene that was significantly associated with the risk of erectile dysfunction (odds ratio = 1.26, P = 3.4 × 10−25). The association replicated in the UK Biobank sample (odds ratio = 1.25, P = 6.8 × 10−14), and the effect is independent of known erectile dysfunction risk factors, including body mass index (BMI). The risk locus resides on the same topologically associating domain as SIM1 and interacts with the SIM1 promoter, and the rs17185536-T risk allele showed differential enhancer activity. SIM1 is part of the leptin–melanocortin system, which has an established role in body weight homeostasis and sexual function. Because the variants associated with erectile dysfunction are not associated with differences in BMI, our findings suggest a mechanism that is specific to sexual function.
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Gonçalves JPL, Palmer D, Meldal M. MC4R Agonists: Structural Overview on Antiobesity Therapeutics. Trends Pharmacol Sci 2018; 39:402-423. [PMID: 29478721 DOI: 10.1016/j.tips.2018.01.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 01/28/2018] [Accepted: 01/30/2018] [Indexed: 01/08/2023]
Abstract
The melanocortin-4 receptor (MC4R) regulates adipose tissue formation and energy homeostasis, and is believed to be a monogenic target for novel antiobesity therapeutics. Several research efforts targeting this receptor have identified potent and selective agonists. While viable agonists have been characterized in vitro, undesirable side effects frequently appeared during clinical trials. The most promising candidates have diverse structures, including linear peptides, cyclic peptides, and small molecules. Herein, we present a compilation of potent MC4R agonists and discuss the pivotal structural differences within those molecules that resulted in good selectivity for MC4R over other melanocortins. We provide insight on recent progress in the field and reflect on directions for development of new agonists.
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Affiliation(s)
- Juliana Pereira Lopes Gonçalves
- Center for Evolutionary Chemical Biology, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark.
| | - Daniel Palmer
- Center for Evolutionary Chemical Biology, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Morten Meldal
- Center for Evolutionary Chemical Biology, Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark.
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14
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Semple E, Hill JW. Sim1 Neurons Are Sufficient for MC4R-Mediated Sexual Function in Male Mice. Endocrinology 2018; 159:439-449. [PMID: 29059347 PMCID: PMC5761591 DOI: 10.1210/en.2017-00488] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Accepted: 10/12/2017] [Indexed: 12/24/2022]
Abstract
Sexual dysfunction is a poorly understood condition that affects up to one-third of men around the world. Existing treatments that target the periphery do not work for all men. Previous studies have shown that central melanocortins, which are released by pro-opiomelanocortin neurons in the arcuate nucleus of the hypothalamus, can lead to male erection and increased libido. Several studies specifically implicate the melanocortin 4 receptor (MC4R) in the central control of sexual function, but the specific neural circuitry involved is unknown. We hypothesized that single-minded homolog 1 (Sim1) neurons play an important role in the melanocortin-mediated regulation of male sexual behavior. To test this hypothesis, we examined the sexual behavior of mice expressing MC4R only on Sim1-positive neurons (tbMC4Rsim1 mice) in comparison with tbMC4R null mice and wild-type controls. In tbMC4Rsim1 mice, MC4R reexpression was found in the medial amygdala and paraventricular nucleus of the hypothalamus. These mice were paired with sexually experienced females, and their sexual function and behavior was scored based on mounting, intromission, and ejaculation. tbMC4R null mice showed a longer latency to mount, a reduced intromission efficiency, and an inability to reach ejaculation. Expression of MC4R only on Sim1 neurons reversed the sexual deficits seen in tbMC4R null mice. This study implicates melanocortin signaling via the MC4R on Sim1 neurons in the central control of male sexual behavior.
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MESH Headings
- Amygdala/drug effects
- Amygdala/metabolism
- Amygdala/pathology
- Animals
- Arcuate Nucleus of Hypothalamus/drug effects
- Arcuate Nucleus of Hypothalamus/metabolism
- Arcuate Nucleus of Hypothalamus/pathology
- Basic Helix-Loop-Helix Transcription Factors/metabolism
- Copulation/drug effects
- Crosses, Genetic
- Fertility Agents, Male/administration & dosage
- Fertility Agents, Male/therapeutic use
- Heterozygote
- Infertility, Male/drug therapy
- Infertility, Male/metabolism
- Infertility, Male/pathology
- Injections, Intraventricular
- Male
- Mice, Knockout
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Neurons/drug effects
- Neurons/metabolism
- Neurons/pathology
- Organ Specificity
- Paraventricular Hypothalamic Nucleus/drug effects
- Paraventricular Hypothalamic Nucleus/metabolism
- Paraventricular Hypothalamic Nucleus/pathology
- Random Allocation
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Repressor Proteins/metabolism
- Sexual Behavior, Animal/drug effects
- alpha-MSH/administration & dosage
- alpha-MSH/therapeutic use
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Affiliation(s)
- Erin Semple
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio 43606
| | - Jennifer W. Hill
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio 43606
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Yang LK, Tao YX. Biased signaling at neural melanocortin receptors in regulation of energy homeostasis. Biochim Biophys Acta Mol Basis Dis 2017; 1863:2486-2495. [PMID: 28433713 DOI: 10.1016/j.bbadis.2017.04.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/09/2017] [Accepted: 04/10/2017] [Indexed: 12/15/2022]
Abstract
The global prevalence of obesity highlights the importance of understanding on regulation of energy homeostasis. The central melanocortin system is an important intersection connecting the neural pathways controlling satiety and energy expenditure to regulate energy homeostasis by sensing and integrating the signals of external stimuli. In this system, neural melanocortin receptors (MCRs), melanocortin-3 and -4 receptors (MC3R and MC4R), play crucial roles in the regulation of energy homeostasis. Recently, multiple intracellular signaling pathways and biased signaling at neural MCRs have been discovered, providing new insights into neural MCR signaling. This review attempts to summarize biased signaling including biased receptor mutants (both naturally occurring and lab-generated) and biased ligands at neural MCRs, and to provide a better understanding of obesity pathogenesis and new therapeutic implications for obesity treatment.
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Affiliation(s)
- Li-Kun Yang
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States
| | - Ya-Xiong Tao
- Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, United States.
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16
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Khandpur S, Porter R, Boulton S, Anstey A. Drug-induced photosensitivity: new insights into pathomechanisms and clinical variation through basic and applied science. Br J Dermatol 2017; 176:902-909. [DOI: 10.1111/bjd.14935] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2016] [Indexed: 12/21/2022]
Affiliation(s)
- S. Khandpur
- Department of Dermatology and Venereology; All India Institute of Medical Sciences; New Delhi India
| | - R.M. Porter
- Academic Dermatology; Aneurin Bevan Health Board, Stow Hill; St Woolos Hospital; Newport NP20 4SZ U.K
| | - S.J. Boulton
- School of Biomedical Sciences; Faculty of Medical Sciences; Newcastle University Medical School, Framlington Place; Newcastle upon Tyne NE2 4HH U.K
| | - A. Anstey
- Betsi Cadwaladr University Health Board; Ysbyty Gwynedd, Penrhosgarnedd; Bangor Gwynedd LL57 2PY U.K
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17
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Corona G, Isidori AM, Aversa A, Burnett AL, Maggi M. Endocrinologic Control of Men's Sexual Desire and Arousal/Erection. J Sex Med 2016; 13:317-37. [PMID: 26944463 DOI: 10.1016/j.jsxm.2016.01.007] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 01/13/2016] [Accepted: 01/15/2016] [Indexed: 01/10/2023]
Abstract
INTRODUCTION Several hormones and neurotransmitters orchestrate men's sexual response, including the appetitive (sexual desire) and consummative (arousal and penile erection) phases. AIM To provide an overview and recommendations regarding endocrinologic control of sexual desire and arousal and erection and their disturbances. METHODS Medical literature was reviewed by the subcommittee of the International Consultation of Sexual Medicine, followed by extensive internal discussion, and then public presentation and discussion with other experts. The role of pituitary (prolactin, oxytocin, growth hormone, and α-melanocyte-stimulating hormone), thyroid, and testicular hormones was scrutinized and discussed. MAIN OUTCOME MEASURES Recommendations were based on grading of evidence-based medical literature, followed by interactive discussion. RESULTS Testosterone has a primary role in controlling and synchronizing male sexual desire and arousal, acting at multiple levels. Accordingly, meta-analysis indicates that testosterone therapy for hypogonadal individuals can improve low desire and erectile dysfunction. Hyperprolactinemia is associated with low desire that can be successfully corrected by appropriate treatments. Oxytocin and α-melanocyte-stimulating hormone are important in eliciting sexual arousal; however, use of these peptides, or their analogs, for stimulating sexual arousal is still under investigation. Evaluation and treatment of other endocrine disorders are suggested only in selected cases. CONCLUSION Endocrine abnormalities are common in patients with sexual dysfunction. Their identification and treatment is strongly encouraged in disturbances of sexual desire and arousal.
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Affiliation(s)
- Giovanni Corona
- Endocrinology Unit, Medical Department, Azienda USL Bologna, Maggiore-Bellaria Hospital, Bologna, Italy.
| | - Andrea M Isidori
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Antonio Aversa
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy; Deptartment of Experimental and Clinical Medicine, University Magna Graecia, Catanzaro, Italy
| | - Arthur L Burnett
- Department of Urology, the James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Mario Maggi
- Sexual Medicine and Andrology Unit, Department of Biomedical, Clinical and Experimental Sciences, University of Florence, Florence, Italy
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Cai M, Hruby VJ. The Melanocortin Receptor System: A Target for Multiple Degenerative Diseases. Curr Protein Pept Sci 2016; 17:488-96. [PMID: 26916163 DOI: 10.2174/1389203717666160226145330] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 01/28/2016] [Accepted: 01/08/2016] [Indexed: 01/10/2023]
Abstract
The melanocortin receptor system consists of five closely related G-protein coupled receptors (MC1R, MC2R, MC3R, MC4R and MC5R). These receptors are involved in many of the key biological functions for multicellular animals, including human beings. The natural agonist ligands for these receptors are derived by processing of a primordial animal gene product, proopiomelanocortin (POMC). The ligand for the MC2R is ACTH (Adrenal Corticotropic Hormone), a larger processed peptide from POMC. The natural ligands for the other 4 melanocortin receptors are smaller peptides including α-melanocyte stimulating hormone (α-MSH) and related peptides from POMC (β-MSH and γ-MSH). They all contain the sequence His-Phe-Arg-Trp that is conserved throughout evolution. Thus, there has been considerable difficulty in developing highly selective ligands for the MC1R, MC3R, MC4R and MC5R. In this brief review, we discuss the various approaches that have been taken to design agonist and antagonist analogues and derivatives of the POMC peptides that are selective for the MC1R, MC3R, MC4R and MC5R receptors, via peptide, nonpeptide and peptidomimetic derivatives and analogues and their differential interactions with receptors that may help account for these selectivities.
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Affiliation(s)
| | - Victor J Hruby
- Department of Chemistry & Biochemistry, University of Arizona, 1306 E. University Blvd, Tucson, AZ 85721, USA.
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19
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Faulkner LD, Dowling AR, Stuart RC, Nillni EA, Hill JW. Reduced melanocortin production causes sexual dysfunction in male mice with POMC neuronal insulin and leptin insensitivity. Endocrinology 2015; 156:1372-85. [PMID: 25590244 PMCID: PMC4399313 DOI: 10.1210/en.2014-1788] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Proopiomelanocortin (POMC)-derived peptides like α-melanocyte-stimulating hormone (MSH) substantially improve hepatic insulin sensitivity and regulate energy expenditure. Melanocortinergic agents are also powerful inducers of sexual arousal that are being investigated for a possible therapeutic role in erectile dysfunction. It is currently unclear whether reduced melanocortin (MC) activity may contribute to the sexual dysfunction accompanying obesity and type 2 diabetes. Male rodents with leptin and insulin resistance targeted to POMC neurons (leptin receptor [LepR]/insulin receptor [IR]POMC mice) exhibit obesity, hyperinsulinemia, hyperglycemia, and systemic insulin resistance. In this study, we demonstrate that LepR/IRPOMC males are also subfertile due to dramatic alterations in sexual behavior. Remarkably, these reproductive changes are accompanied by decreased α-MSH production not present when a single receptor type is deleted. Unexpectedly, behavioral sensitivity to α-MSH and MC receptor expression are also reduced in LepR/IRPOMC males, a potential adaptation of the MC system to altered α-MSH production. Together, these results suggest that concurrent insulin and leptin resistance in POMC neurons in individuals with obesity or type 2 diabetes can reduce endogenous α-MSH levels and impair sexual function.
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Affiliation(s)
- Latrice D Faulkner
- Department of Physiology and Pharmacology (L.D.F., A.R.D., J.W.H.), College of Medicine, The University of Toledo, Toledo, Ohio 43614-2598; and Division of Endocrinology (R.C.S., E.A.N.), Department of Medicine, The Warren Alpert Medical School of Brown University, Providence, Rhode Island 02912-9107
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Breindahl T, Evans-Brown M, Hindersson P, McVeigh J, Bellis M, Stensballe A, Kimergård A. Identification and characterization by LC-UV-MS/MS of melanotan II skin-tanning products sold illegally on the Internet. Drug Test Anal 2014; 7:164-72. [DOI: 10.1002/dta.1655] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/07/2014] [Accepted: 03/08/2014] [Indexed: 01/19/2023]
Affiliation(s)
- Torben Breindahl
- Department of Clinical Biochemistry, Vendsyssel Hospital; (Aalborg University); Denmark
| | | | - Peter Hindersson
- Department of Clinical Biochemistry, Vendsyssel Hospital; (Aalborg University); Denmark
| | - Jim McVeigh
- Centre for Public Health; Liverpool John Moores University; United Kingdom
| | - Mark Bellis
- Centre for Public Health; Liverpool John Moores University; United Kingdom
| | - Allan Stensballe
- Department of Health Science and Technology; Aalborg University; Denmark
| | - Andreas Kimergård
- Centre for Public Health; Liverpool John Moores University; United Kingdom
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Royalty JE, Konradsen G, Eskerod O, Wulff BS, Hansen BS. Investigation of safety, tolerability, pharmacokinetics, and pharmacodynamics of single and multiple doses of a long-acting α-MSH analog in healthy overweight and obese subjects. J Clin Pharmacol 2014; 54:394-404. [PMID: 24166760 PMCID: PMC4263154 DOI: 10.1002/jcph.211] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Accepted: 10/17/2013] [Indexed: 11/07/2022]
Abstract
MC4-NN2-0453 is a novel, long-acting, selective, melanocortin-4-receptor agonist developed for treatment of obesity. This first-human-dose, randomized, double-blind, placebo-controlled trial investigated the safety, tolerability, pharmacokinetics, and pharmacodynamics of single and multiple doses of MC4-NN2-0453 in overweight to obese but otherwise healthy subjects. The trial included a single-dose part of ascending subcutaneous 0.03-1.50 mg/kg doses in overweight to obese but otherwise healthy men, and a multiple-dose part of ascending subcutaneous 0.75-3.0 mg/day doses in obese but otherwise healthy men/women. The single-dose part included 7 cohorts of 8 subjects, randomized 6:2 to active drug/placebo; the multiple-dose part included 4 cohorts of 20 subjects, randomized 16:4 to active drug/placebo. MC4-NN2-0453 was well tolerated and raised no safety concerns except for nonserious skin-related adverse events, this along with lack of weight loss effect led to premature termination of the trial. Headache, sexual-arousal disturbance, and penile erection were also reported. Single-dose pharmacokinetics showed dose-linearity and dose-proportionality. Maximum plasma concentration was observed after 50-100 hours, which then declined with a of approximately 250 hours. Plasma concentration reached steady state after 4 weeks for 0.75 and 1.5 mg/day multiple-dose cohorts, and the was similar to single dose. There were no significant pharmacodynamic effects, including effect on body weight.
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22
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Kim GW, Lin JE, Blomain ES, Waldman SA. Antiobesity pharmacotherapy: new drugs and emerging targets. Clin Pharmacol Ther 2013; 95:53-66. [PMID: 24105257 DOI: 10.1038/clpt.2013.204] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 09/18/2013] [Indexed: 02/07/2023]
Abstract
Obesity is a growing pandemic, and related health and economic costs are staggering. Pharmacotherapy, partnered with lifestyle modifications, forms the core of current strategies to reduce the burden of this disease and its sequelae. However, therapies targeting weight loss have a significant history of safety risks, including cardiovascular and psychiatric events. Here, evolving strategies for developing antiobesity therapies, including targets, mechanisms, and developmental status, are highlighted. Progress in this field is underscored by Belviq (lorcaserin) and Qsymia (phentermine/topiramate), the first agents in more than 10 years to achieve regulatory approval for chronic weight management in obese patients. On the horizon, novel insights into metabolism and energy homeostasis reveal guanosine 3',5'-cyclic monophosphate (cGMP) signaling circuits as emerging targets for antiobesity pharmacotherapy. These innovations in molecular discovery may elegantly align with practical off-the-shelf approaches, leveraging existing approved drugs that modulate cGMP levels for the management of obesity.
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Affiliation(s)
- G W Kim
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - J E Lin
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - E S Blomain
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - S A Waldman
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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23
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Hruby VJ, Cai M. Design of peptide and peptidomimetic ligands with novel pharmacological activity profiles. Annu Rev Pharmacol Toxicol 2013; 53:557-80. [PMID: 23294313 DOI: 10.1146/annurev-pharmtox-010510-100456] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Peptide hormones and neurotransmitters are of central importance in most aspects of intercellular communication and are involved in virtually all degenerative diseases. In this review, we discuss physicochemical approaches to the design of novel peptide and peptidomimetic agonists, antagonists, inverse agonists, and related compounds that have unique biological activity profiles, reduced toxic side effects, and, if desired, the ability to cross the blood-brain barrier. Designing ligands for specific biological and medical needs is emphasized, as is the close collaboration of chemists and biologists to maximize the chances for success. Special emphasis is placed on the use of conformational (ϕ-ψ space) and topographical (χ space) considerations in design.
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Affiliation(s)
- Victor J Hruby
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona 85721, USA.
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24
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Argiolas A, Melis MR. Neuropeptides and central control of sexual behaviour from the past to the present: a review. Prog Neurobiol 2013; 108:80-107. [PMID: 23851261 DOI: 10.1016/j.pneurobio.2013.06.006] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2013] [Revised: 06/28/2013] [Accepted: 06/29/2013] [Indexed: 12/23/2022]
Abstract
Of the numerous neuropeptides identified in the central nervous system, only a few are involved in the control of sexual behaviour. Among these, the most studied are oxytocin, adrenocorticotropin, α-melanocyte stimulating hormone and opioid peptides. While opioid peptides inhibit sexual performance, the others facilitate sexual behaviour in most of the species studied so far (rats, mice, monkeys and humans). However, evidence for a sexual role of gonadotropin-releasing hormone, corticotropin releasing factor, neuropeptide Y, galanin and galanin-like peptide, cholecystokinin, substance P, vasoactive intestinal peptide, vasopressin, angiotensin II, hypocretins/orexins and VGF-derived peptides are also available. Corticotropin releasing factor, neuropeptide Y, cholecystokinin, vasopressin and angiotensin II inhibit, while substance P, vasoactive intestinal peptide, hypocretins/orexins and some VGF-derived peptide facilitate sexual behaviour. Neuropeptides influence sexual behaviour by acting mainly in the hypothalamic nuclei (i.e., lateral hypothalamus, paraventricular nucleus, ventromedial nucleus, arcuate nucleus), in the medial preoptic area and in the spinal cord. However, it is often unclear whether neuropeptides influence the anticipatory phase (sexual arousal and/or motivation) or the consummatory phase (performance) of sexual behaviour, except in a few cases (e.g., opioid peptides and oxytocin). Unfortunately, scarce information has been added in the last 15 years on the neural mechanisms by which neuropeptides influence sexual behaviour, most studied neuropeptides apart. This may be due to a decreased interest of researchers on neuropeptides and sexual behaviour or on sexual behaviour in general. Such a decrease may be related to the discovery of orally effective, locally acting type V phosphodiesterase inhibitors for the therapy of erectile dysfunction.
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Affiliation(s)
- Antonio Argiolas
- Department of Biomedical Sciences, University of Cagliari, Cagliari, Italy.
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25
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Krishna R, Wong P, Stevens C, De Lepeleire I, Van Dyck K, Rosen RC, Gendrano IN, Peeters M, Wagner JA, Herman GA. Lack of Erectogenic Activity of a Novel Selective Melanocortin-4 Receptor Agonist in a Clinical Experimental Model. J Clin Pharmacol 2013; 48:1237-41. [DOI: 10.1177/0091270008320925] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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26
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Giuliano F. Control of Penile Erection by the Melanocortinergic System: Experimental Evidences and Therapeutic Perspectives. ACTA ACUST UNITED AC 2013; 25:683-91. [PMID: 15292097 DOI: 10.1002/j.1939-4640.2004.tb02842.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- François Giuliano
- Department of Urology, CHU de Bicêtre, 78 rue du Général Leclerc, 94270 Le Kremlin Bicêtre Cedex, France.
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27
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The melanocortin 1 receptor (MC1R) inhibits the inflammatory response in Raw 264.7 cells and atopic dermatitis (AD) mouse model. Mol Biol Rep 2012; 40:1987-96. [PMID: 23090482 DOI: 10.1007/s11033-012-2256-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 10/10/2012] [Indexed: 01/04/2023]
Abstract
The alpha melanocyte stimulating hormone receptor (MC1R) is one of five G-protein coupled receptors belonging to the melanocortin subfamily, MC1R gene has been known to play a major role in regulating of fur color in mammals, and α-MSH and ACTH are endogenous nonselective agonists for MC1R. However, we found that MC1R was highly expressed in Raw 264.7 cells which were important inflammatory cells involved in the initiation of inflammatory responses. In addition, Cyclic AMP is not only a key molecule in the MC1R signal transduction pathway, but dampen innate immune-mediated responses. These intriguing biological results triggered the further conformation studies; it suggested that MC1R was very likely to be an important role in immunoregulation. In this study, we were to investigate the immunosuppressive effects of MC1R on inflammation in lipopolysaccharide (LPS) stimulated Raw 264.7 cells and LPS induced vivo 2-chloro-1,3,5-trinitrobenzene (TNCB)-induced atopic dermatitis (AD) model. The effects of the MC1R antagonist psoralen on pro-inflammatory cytokines and signaling pathways were analyzed by enzyme-linked immunosorbent assay, western blot, real-time fluorescence quantitative PCR and Histological analysis. Our results show a consistent and marked effect of high concentrations of MC1R antagonist psoralen increased the level of MC1R mRNA in Raw 264.7 cells by cumulative feedback regulation through preferential binding of MC1R. Moreover, as evidenced by inhibiting the LPS-induced TNF-α, IL-6 and enhancing the expression level of cyclic AMP protein in vitro. In vivo study it was also observed that psoralen promoted on histopathologic changes in the skin tissue of TNCB-induced AD mice. Taken together, our results suggest that MC1R decrease the inflammation in vitro and vivo, and might be a therapeutic signaling pathway to against inflammatory diseases.
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Caquineau C, Leng G, Douglas AJ. Sexual behaviour and neuronal activation in the vomeronasal pathway and hypothalamus of food-deprived male rats. J Neuroendocrinol 2012; 24:712-23. [PMID: 22309296 DOI: 10.1111/j.1365-2826.2012.02290.x] [Citation(s) in RCA: 14] [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: 01/14/2023]
Abstract
As feeding and mating are mutually-exclusive goal-orientated behaviours, we investigated whether brief food deprivation would impair the display of sexual behaviour of male rats. Analysis of performance in a sexual incentive motivation test revealed that, similar to fed males, food-deprived males preferred spending time in the vicinity of receptive females rather than nonreceptive females. Despite this, food-deprived males were more likely to be slow to mate than normally-fed males, and a low dose of the satiety peptide α-melanocyte-stimulating-hormone attenuated the effect of hunger. Using Fos immunocytochemistry, we compared neuronal activity in the vomeronasal projection pathway in response to oestrous cues from receptive females between food-deprived and fed males. As in fed males, more Fos expression was seen in the rostral part of the bed nucleus of the stria terminalis and in the medial preoptic area in food-deprived males, confirming that food-deprived males can recognise and respond to female oestrous cues. However, although there was also an increase in Fos expression in the bed nucleus of the accessory tract and in the posteromedial amygdala in fed males, no increases were seen in these areas in food-deprived rats. We also found selective attenuation in the activation of lateral posterior paraventricular nucleus (lpPVN) oxytocin neurones in food-deprived males. Taken together, the data show that, although food-deprived males can still become sexually motivated, copulation is delayed, and this is accompanied by variations in neuronal activity in the vomeronasal projection pathway. We propose that, in hungry rats, the lpPVN oxytocin neurones (which project to the spinal cord and are involved in maintaining penile erection) facilitate the transition from motivation to intromission, and their lack of activation impairs intromission, and thus delays mating.
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Affiliation(s)
- C Caquineau
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK.
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29
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Murray SH, Milhausen RR. Sexual desire and relationship duration in young men and women. JOURNAL OF SEX & MARITAL THERAPY 2012; 38:28-40. [PMID: 22268980 DOI: 10.1080/0092623x.2011.569637] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Sexual desire is often present at the beginning of a romantic relationship. However, research is divided regarding whether, and how, desire is experienced as a relationship progresses. The authors examined relationship duration and its effect on sexual desire in a sample of 170 undergraduate men and women between the ages of 18 and 25 years. Hierarchical multiple regression results indicated that women's sexual desire was significantly and negatively predicted by relationship duration after controlling for age, relationship satisfaction, and sexual satisfaction. Men's sexual desire, however, was not significantly affected by the duration of their romantic relationships. These findings suggest that men and women may have different experiences with sexual desire as relationships progress and that sexual desire might be affected by different factors depending on one's gender. Possible reasons for these results are suggested and therapeutic implications are discussed.
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Affiliation(s)
- Sarah H Murray
- Department of Family Relations and Applied Nutrition, University of Guelph, Guelph, Ontario, Canada.
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Alwaal A, Al-Mannie R, Carrier S. Future prospects in the treatment of erectile dysfunction: focus on avanafil. DRUG DESIGN DEVELOPMENT AND THERAPY 2011; 5:435-43. [PMID: 22087063 PMCID: PMC3210072 DOI: 10.2147/dddt.s15852] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/17/2011] [Indexed: 01/17/2023]
Abstract
The treatment of erectile dysfunction (ED) has been revolutionized in the last 15 years with the introduction of type 5 phosphodiesterase (PDE5) inhibitors. Their efficacy, safety, and ease of administration have made them first-line treatment for ED. This article reviews the current therapies available for ED, and the new PDE5 inhibitors that are being investigated. Furthermore, it examines all the current ED treatment options that are in different phases of development (including oral and topical pharmacotherapy, gene therapy, and tissue engineering). A special emphasis is on avanafil, a new PDE5 inhibitor that has been studied extensively in Phase I and II clinical trials and has undergone several Phase III trials. Avanafil is a promising medication for ED due to its favorable pharmacokinetics, safety, and efficacy.
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Affiliation(s)
- Amjad Alwaal
- Division of Urology, McGill University Health Centre, Montreal, Quebec, Canada
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Grieco P, Brancaccio D, Novellino E, Hruby VJ, Carotenuto A. Conformational study on cyclic melanocortin ligands and new insight into their binding mode at the MC4 receptor. Eur J Med Chem 2011; 46:3721-33. [PMID: 21652123 DOI: 10.1016/j.ejmech.2011.05.038] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 05/12/2011] [Accepted: 05/14/2011] [Indexed: 11/30/2022]
Abstract
The melanocortin receptors are involved in many physiological functions, including pigmentation, sexual function, feeding behavior, and energy homeostasis, making them potential targets to treat obesity, sexual dysfunction, etc. Understanding the basis of the ligand-receptor interactions is crucial for the design of potent and selective ligands for these receptors. The conformational preferences of the cyclic melanocortin ligands MTII (Ac-Nle(4)-c[Asp(5)-His(6)-DPhe(7)-Arg(8)-Trp(9)-Lys(10)]-NH(2)) and SHU9119 (Ac-Nle(4)-c[Asp(5)-His(6)-DNal(2')(7)-Arg(8)-Trp(9)-Lys(10)]-NH(2)), which show agonist and antagonist activity at the h-MC4R, respectively, were comprehensively investigated by solution NMR spectroscopy in different environments. In particular, water and water/DMSO (8:2) solutions were used as isotropic solutions and an aqueous solution of DPC (dodecylphosphocholine) micelles was used as a membrane mimetic environment. NMR-derived conformations of these two ligands were docked within h-MC4R models. NMR and docking studies revealed intriguing differences which can help explain the different activities of these two ligands.
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Affiliation(s)
- Paolo Grieco
- Department of Pharmaceutical and Toxicological Chemistry, University of Naples Federico II, I-80131 Naples, Italy
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Hruby VJ, Cai M, Nyberg J, Muthu D. Approaches to the rational design of selective melanocortin receptor antagonists. Expert Opin Drug Discov 2011; 6:543-57. [PMID: 22646078 DOI: 10.1517/17460441.2011.565743] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION When establishing the physiological roles of specific receptors in normal and disease states, it is critical to have selective antagonist ligands for each receptor in a receptor system with several subtypes. The melanocortin receptors have five subtypes referred to as the melanocortin 1 receptor, melanocortin 2 receptor, melanocortin 3 receptor, melanocortin 4 receptor and melanocortin 5 receptor, and they are of critical importance for many aspects of human health and disease. AREAS COVERED This article reviews the current efforts to design selective antagonistic ligands for the five human melanocortin receptors summarizing the currently published orthosteric and allosteric antagonists for each of these receptors. EXPERT OPINION Though there has been progress, there are still few drugs available that address the many significant biological activities and diseases that are associated with these receptors, which is possibly due to the lack of receptor selectivity that these designed ligands are currently showing. The authors believe that further studies into the antagonists' 3D conformational and topographical properties in addition to future mutagenesis studies will provide greater insight into these ligands which could play a role in the treatment of various diseases in the future.
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Affiliation(s)
- Victor J Hruby
- University of Arizona, Department of Chemistry and Biochemistry , 1306 E. University Blvd., Tucson, AZ 85721 , USA
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Siljee-Wong JE. Melanocortin MC₄ receptor expression sites and local function. Eur J Pharmacol 2011; 660:234-40. [PMID: 21199645 DOI: 10.1016/j.ejphar.2010.10.104] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 09/30/2010] [Accepted: 10/12/2010] [Indexed: 01/09/2023]
Abstract
The melanocortin MC(4) receptor plays an important role in energy metabolism, but also affects blood pressure, heart rate and erectile function. Localization of the receptors that fulfill these distinct roles is only partially known. Mapping of the melanocortin MC(4) receptor has been stymied by the absence of a functional antibody. Several groups have examined mRNA expression of the melanocortin MC(4) receptor in the rodent brain and transgenic approaches have also been utilized to visualize melanocortin MC(4) receptor expression sites within the brain. Ligand expression and binding studies have provided additional information on the areas of the brain where this elusive receptor is functionally expressed. Finally, microinjection of melanocortin MC(4) receptor ligands in specific nuclei has further served to elucidate the function of melanocortin MC(4) receptors in these nuclei. These combined approaches have helped link the anatomy and function of this receptor, such as the role of paraventricular hypothalamic nucleus melanocortin MC(4) receptor in the regulation of food intake. Intriguingly, however, numerous expression-sites have been identified that have not been linked to a specific receptor function such as those along the optic tract and olfactory tubercle. Further research is needed to clarify the function of the melanocortin MC(4) receptor at these sites.
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Affiliation(s)
- Jacqueline E Siljee-Wong
- Department of Endocrinology and Metabolism, Amsterdam Medical Center, Meibergdreef 47 1105 BA Amsterdam, the Netherlands.
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Abstract
The melanocortin-4 receptor (MC4R) was cloned in 1993 by degenerate PCR; however, its function was unknown. Subsequent studies suggest that the MC4R might be involved in regulating energy homeostasis. This hypothesis was confirmed in 1997 by a series of seminal studies in mice. In 1998, human genetic studies demonstrated that mutations in the MC4R gene can cause monogenic obesity. We now know that mutations in the MC4R are the most common monogenic form of obesity, with more than 150 distinct mutations reported thus far. This review will summarize the studies on the MC4R, from its cloning and tissue distribution to its physiological roles in regulating energy homeostasis, cachexia, cardiovascular function, glucose and lipid homeostasis, reproduction and sexual function, drug abuse, pain perception, brain inflammation, and anxiety. I will then review the studies on the pharmacology of the receptor, including ligand binding and receptor activation, signaling pathways, as well as its regulation. Finally, the pathophysiology of the MC4R in obesity pathogenesis will be reviewed. Functional studies of the mutant MC4Rs and the therapeutic implications, including small molecules in correcting binding and signaling defect, and their potential as pharmacological chaperones in rescuing intracellularly retained mutants, will be highlighted.
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Affiliation(s)
- Ya-Xiong Tao
- Department of Anatomy, Physiology, and Pharmacology, Auburn University, Alabama 36849-5519, USA.
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Doedens L, Opperer F, Cai M, Beck JG, Dedek M, Palmer E, Hruby VJ, Kessler H. Multiple N-methylation of MT-II backbone amide bonds leads to melanocortin receptor subtype hMC1R selectivity: pharmacological and conformational studies. J Am Chem Soc 2010; 132:8115-28. [PMID: 20496895 PMCID: PMC2895553 DOI: 10.1021/ja101428m] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Multiple N-methylation is a novel technology to improve bioavailability of peptides and increase receptor subtype selectivity. This technique has been applied here to the superpotent but nonselective cyclic peptide MT-II. A library of all possible 31 backbone N-methylated derivatives has been synthesized and tested for binding and activation at melanocortin receptor subtypes 1, 3, 4, and 5. It turned out that selectivity is improved with every introduced N-methyl group, resulting in several N-methylated selective and potent agonists for the hMC1R. The most potent of these derivatives is N-methylated on four out of five amide bonds in the cyclic structure. Its solution structure indicates a strongly preferred backbone conformation that resembles other alpha-MSH analogs but possesses much less flexibility and in addition distinct differences in the spatial arrangement of individual amino acid side chains.
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Affiliation(s)
- Lucas Doedens
- Institute for Advanced Study and Center for Integrated Protein Science at the Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Florian Opperer
- Institute for Advanced Study and Center for Integrated Protein Science at the Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Minying Cai
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721, U.S.A
| | - Johannes G. Beck
- Institute for Advanced Study and Center for Integrated Protein Science at the Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
| | - Matt Dedek
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721, U.S.A
| | - Erin Palmer
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721, U.S.A
| | - Victor J. Hruby
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, Arizona, 85721, U.S.A
| | - Horst Kessler
- Institute for Advanced Study and Center for Integrated Protein Science at the Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany
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Fridmanis D, Petrovska R, Kalnina I, Slaidina M, Peculis R, Schiöth HB, Klovins J. Identification of domains responsible for specific membrane transport and ligand specificity of the ACTH receptor (MC2R). Mol Cell Endocrinol 2010; 321:175-83. [PMID: 20206229 DOI: 10.1016/j.mce.2010.02.032] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Revised: 02/23/2010] [Accepted: 02/23/2010] [Indexed: 12/26/2022]
Abstract
The adrenocorticotropic hormone (ACTH) receptor has highly specific membrane expression that is limited to adrenal cells; in other cell types the polypeptide fails to be transported to the cell surface. Unlike other evolutionarily related members of the melanocortin receptor family (MC1R-MC5R) that recognize different melanocortin peptides, ACTHR (MC2R) binds only ACTH. We used a mutagenesis approach involving systematic construction of chimeric ACTHR/MC4R receptors to identify the domains determining the selectivity of ACTHR membrane transport and ACTH binding. In total 15 chimeric receptors were created by replacement of selected domains of human ACTHR with the corresponding regions of human MC4R. We developed an analytical method to accurately quantify cell-membrane localization of recombinant receptors fused with enhanced green fluorescent protein by confocal fluorescence microscopy. The chimeric receptors were also tested for their ability to bind ACTH (1-24) and the melanocyte-stimulating hormone (MSH) analog, Nle4, DPhe7-alpha-MSH, and to induce a cAMP response. Our results indicate that substitution of the MC4R N-terminal segment with the homologous segment of ACTHR significantly decreased membrane transport. We also identified another signal localized in the third and fourth transmembrane regions as the main determinant of ACTHR intracellular retention. In addition, we found that the fourth and fifth transmembrane domains of the ACTHR are involved in ACTH binding selectivity. We discuss the mechanisms involved in bypassing these arrest signals via an interaction with melanocortin 2 receptor accessory protein (MRAP) and the possible mechanisms that determine the high ligand-binding specificity of ACTHR.
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Lansdell MI, Hepworth D, Calabrese A, Brown AD, Blagg J, Burring DJ, Wilson P, Fradet D, Brown TB, Quinton F, Mistry N, Tang K, Mount N, Stacey P, Edmunds N, Adams C, Gaboardi S, Neal-Morgan S, Wayman C, Cole S, Phipps J, Lewis M, Verrier H, Gillon V, Feeder N, Heatherington A, Sultana S, Haughie S, Martin SW, Sudworth M, Tweedy S. Discovery of a Selective Small-Molecule Melanocortin-4 Receptor Agonist with Efficacy in a Pilot Study of Sexual Dysfunction in Humans. J Med Chem 2010; 53:3183-97. [DOI: 10.1021/jm9017866] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Mark I. Lansdell
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - David Hepworth
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Andrew Calabrese
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Alan D. Brown
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Julian Blagg
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Denise J. Burring
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Peter Wilson
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - David Fradet
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - T. Bruce Brown
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Faye Quinton
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Neela Mistry
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Kim Tang
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Natalie Mount
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Peter Stacey
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Nick Edmunds
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Cathryn Adams
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Samantha Gaboardi
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Stevie Neal-Morgan
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Chris Wayman
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Susan Cole
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Joanne Phipps
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Mark Lewis
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Hugh Verrier
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Val Gillon
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Neil Feeder
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Anne Heatherington
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Stefan Sultana
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Scott Haughie
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Steven W. Martin
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Maria Sudworth
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
| | - Sarah Tweedy
- Pfizer Global Research and Development, Sandwich Laboratories, Ramsgate Road, Sandwich, Kent CT13 9NJ, U.K
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Abstract
BACKGROUND The guanidine group defines chemical and physicochemical properties of many compounds of medical interest and guanidine-containing derivatives constitute a very important class of therapeutic agents suitable for the treatment of a wide spectrum of diseases. OBJECTIVE To review the most important pharmacological properties, mechanisms of action and therapeutic uses of simple guanidine derivatives, cyclic analogues of guanidines as well as peptides, peptidomimetics and peptoids incorporating arginine. METHODS The review presents both the recent patent literature and original papers dealing with guanidine derivatives that show interesting biological activity and emphasizes the newest developing drugs. CONCLUSION Recent achievements in the synthesis of guanidine-containing molecules with diverse chemical, biochemical and pharmacological properties make them of great importance to the design and development of novel drugs acting at CNS, anti-inflammatory agents, inhibitors of Na(+)/H(+) exchanger, inhibitors of NO synthase, antithrombotic, antidiabetic and chemotherapeutic agents as well as guanidinium-based transporters and vectors.
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Affiliation(s)
- Franciszek Saczewski
- Department of Chemical Technology of Drugs, Medical University of Gdansk, Al. Gen. Hallera 107, Gdansk, Poland.
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Eves PC, Haycock JW. Melanocortin Signalling Mechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 681:19-28. [DOI: 10.1007/978-1-4419-6354-3_2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Eardley I, Donatucci C, Corbin J, El-Meliegy A, Hatzimouratidis K, McVary K, Munarriz R, Lee SW. Pharmacotherapy for Erectile Dysfunction. J Sex Med 2010; 7:524-40. [DOI: 10.1111/j.1743-6109.2009.01627.x] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
From a scientific perspective, efforts to understand biology including what constitutes health and disease has become a chemical problem. However, chemists and biologists "see" the problems of understanding biology from different perspectives, and this has retarded progress in solving the problems especially as they relate to health and disease. This suggests that close collaboration between chemists and biologists is not only necessary but essential for progress in both the biology and chemistry that will provide solutions to the global questions of biology. This perspective has directed my scientific efforts for the past 45 years, and in this overview I provide my perspective of how the applications of synthetic chemistry, structural design, and numerous other chemical principles have intersected in my collaborations with biologists to provide new tools, new science, and new insights that were only made possible and fruitful by these collaborations.
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Affiliation(s)
- Victor J Hruby
- Department of Chemistry and Biochemistry, The University of Arizona, Tucson, Arizona 85721, USA.
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Yang Y, Hruby VJ, Chen M, Crasto C, Cai M, Harmon CM. Novel binding motif of ACTH analogues at the melanocortin receptors. Biochemistry 2009; 48:9775-84. [PMID: 19743876 DOI: 10.1021/bi900634e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The melanocortin receptor (MCR) subtype family is a member of the GPCR superfamily, and each of them has a different pharmacological profile with regard to the relative potency of the endogenous and synthetic melanocortin peptides. Alpha-MSH and ACTH are endogenous nonselective agonists for MC1R, MC3R, MC4R, and MC5R. In this study, we examined the role of Phe(7) in ACTH on human (h) MC1R, MC3R, and MC4R binding and signaling. Our results indicate that substitution of Phe(7) with d-Nal(2')(7) in ACTH1-24 yields a pharmacological profile different from that for substitution of Phe(7) with d-Nal(2')(7) in MSH in hMC1R, hMC3R, and hMC4R. N-d-Nal(2')(7)-ACTH1-24 is an agonist at hMC3R and hMC4R which did not change the peptide from an agonist to an antagonist at hMC3R and hMC4R. Further experiments indicate that N-d-Nal(2')(7)-ACTH1-17 is the minimal peptide required for hMC3R and hMC4R activation. Single-amino acid substitution studies of d-Nal(2')(7)-ACTH1-17 indicate that amino acid residues 15-17 in N-d-Nal(2')(7)-ACTH1-17 are crucial for hMC3R and hMC4R activation. Substitutions of these amino acid residues reduced or abolished agonist activity at hMC3R and hMC4R. Conformational studies revealed a new beta-turn (Arg(8)-Trp(9)-Gly(10)-Lys(11)) in N-d-Nal(2')(7)-ACTH1-17, compared to the beta-turn-like structure at NDP-alpha-MSH (His(6)-d-Phe(7)-Arg(8)-Trp(9)). Our results suggest that NDP-alpha-MSH and N-d-Nal(2')(7)-ACTH1-17 do not share the same binding site; the highly basic C-terminal fragment (Lys(15)-Lys(16)-Arg(17)) of N-d-Nal(2')(7)-ACTH1-17 induced a new beta-turn, and this shift contributed the selective agonist activity at hMC3R and hMC4R.
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Affiliation(s)
- Yingkui Yang
- Department of Surgery, University of Alabama, Birmingham, Alabama 35233, USA.
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Qu H, Cai M, Mayorov AV, Grieco P, Zingsheim M, Trivedi D, Hruby VJ. Substitution of arginine with proline and proline derivatives in melanocyte-stimulating hormones leads to selectivity for human melanocortin 4 receptor. J Med Chem 2009; 52:3627-35. [PMID: 19473029 DOI: 10.1021/jm801300c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new series of melanotropin analogues with His or Arg residues in the core pharmacophores of MTII, SHU9119, and Ac-NDP-gamma-MSH-NH(2) replaced by Pro or trans-/cis-4-guanidinyl-Pro derivatives were designed and synthesized to introduce selectivity toward the human melanocortin 4 receptor (hMC4R). Analogues 1, 2, 3, 6, 7, 8 were found to be hMC4R selective. Second messenger studies have demonstrated that analogues 1 and 2 are insurmountable inhibitors of MTII agonist activity at the hMC4R. Molecular modeling studies suggest that the hMC4R selectivity is due to a beta-turn shift induced by the Pro ring that makes the global minimum structures of these analogues resemble the NMR solution structure of the hASIP melanocortin receptor binding motif. Substitution of His in MTII also provided functional selectivity for the hMC3R or the hMC4R. These findings are important for a better understanding of the selectivity mechanism at the hMC3R/hMC4R and the development of therapeutic ligands selectively targeting the hMC4R.
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Affiliation(s)
- Hongchang Qu
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721, USA
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Kimura Y, Naitou Y, Wanibuchi F, Yamaguchi T. 5-HT2C receptor activation is a common mechanism on proerectile effects of apomorphine, oxytocin and melanotan-II in rats. Eur J Pharmacol 2008; 589:157-62. [DOI: 10.1016/j.ejphar.2008.05.022] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 04/25/2008] [Accepted: 05/19/2008] [Indexed: 11/15/2022]
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Safarinejad MR, Hosseini SY. Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo controlled study. J Urol 2008; 179:1066-71. [PMID: 18206919 DOI: 10.1016/j.juro.2007.10.063] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2007] [Indexed: 01/12/2023]
Abstract
PURPOSE We evaluated the safety and efficacy of intranasal bremelanotide in men with erectile dysfunction who did not respond to sildenafil. MATERIALS AND METHODS A total of 342 married men (28 to 59 years old) with erectile dysfunction who did not respond to sildenafil were randomly assigned to receive 10 mg bremelanotide as an intranasal spray (group 1, 172) 45 minutes to 2 hours prior to sexual stimulation, or a similar regimen of placebo (group 2, 170). Patients were asked to use at least 16 doses/attempts at home. They underwent preliminary assessment, including medical and sexual history, and self-administered International Index of Erectile Function. The efficacy of 2 treatments was assessed every 4 attempts during treatment and at the end of study, using responses to International Index of Erectile Function, and evaluation of mean intercourse satisfaction domain, mean weekly coitus episodes and adverse drug effects. RESULTS Positive clinical results were seen in 51 (33.5%) patients in the bremelanotide group compared with 13 (8.5%) patients in the placebo group (p = 0.03). Patients in the bremelanotide group reported significantly greater intercourse satisfaction than those in placebo group (p = 0.03). More drug related adverse effects occurred in the bremelanotide group (p = 0.01). CONCLUSIONS Bremelanotide can be an alternative treatment for erectile dysfunction with a potentially broad patient base. Further studies with different dosages and treatment regimens are necessary to draw final conclusions on the efficacy of this drug in erectile dysfunction.
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Affiliation(s)
- Mohammad Reza Safarinejad
- Urology and Nephrology Research Center, Shaheed Modarress Hospital, Shaheed Beheshti University of Medical Sciences, Tehran, Iran.
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Miner MM, Seftel AD. Centrally acting mechanisms for the treatment of male sexual dysfunction. Urol Clin North Am 2008; 34:483-96, v. [PMID: 17983889 DOI: 10.1016/j.ucl.2007.08.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The development of pharmacologic therapy for erectile dysfunction (ED) has been possible because of incremental growth in our understanding of the physiology of normal erections and the complex pathophysiology of ED. Although the oral phosphodiesterase type 5 (PDE5) inhibitors have provided safe, effective treatment of ED for some men, a large proportion of men who have ED do not respond to PDE5 inhibitors or become less responsive or less satisfied as the duration of therapy increases. Also, men who are receiving organic nitrates and nitrates, such as amyl nitrate, cannot take PDE5 inhibitors because of nitrate interactions. The current options for treatment beyond PDE5 inhibitors are invasive, unappealing to some patients, and sometimes ineffective. The search for other options by which ED can be treated has branched out and now encompasses centrally acting mechanisms that control erectile function. Drugs available in Europe include apomorphine. This article focuses on the mechanism of centrally acting agents and reviews clinical data on potential new centrally acting drugs for men who have ED.
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Affiliation(s)
- Martin M Miner
- Division of Biology and Medicine, Department of Family Medicine, Warren Alpert Medical School of Brown University, Providence, RI, USA.
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49
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Mayorov AV, Cai M, Palmer ES, Dedek MM, Cain JP, Van Scoy AR, Tan B, Vagner J, Trivedi D, Hruby VJ. Structure-activity relationships of cyclic lactam analogues of alpha-melanocyte-stimulating hormone (alpha-MSH) targeting the human melanocortin-3 receptor. J Med Chem 2008; 51:187-95. [PMID: 18088090 PMCID: PMC2587288 DOI: 10.1021/jm070461w] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A variety of dicarboxylic acid linkers introduced between the alpha-amino group of Pro(6) and the -amino group of Lys(10) of the cyclic lactam alpha-melanocyte-stimulating hormone (alpha-MSH)-derived Pro(6)-D-Phe(7)/D-Nal(2')(7)-Arg(8)-Trp(9)-Lys(10)-NH2 pentapeptide template lead to nanomolar range and selective hMC3R agonists and antagonists. Replacement of the Pro(6) residue and the dicarboxylic acid linker with 2,3-pyrazine-dicarboxylic acid furnished a highly selective nanomolar range hMC3R partial agonist (analogue 12, c[CO-2,3-pyrazine-CO-D-Phe-Arg-Trp-Lys]-NH2, EC50 = 27 nM, 70% max cAMP) and an hMC3R antagonist (analogue 13, c[CO-2,3-pyrazine-CO-D-Nal(2')-Arg-Trp-Lys]-NH2, IC50 = 23 nM). Modeling experiments suggest that 2,3-pyrazinedicarboxylic acid stabilizes a beta-turn-like structure with the D-Phe/D-Nal(2') residues, which explains the high potency of the corresponding peptides. Placement of a Nle residue in position 6 produced a hMC3R/hMC5R antagonist (analogue 15, c[CO-(CH 2)2-CO-Nle-D-Nal(2')-Arg-Trp-Lys]-NH2, IC50 = 12 and 17 nM, respectively), similarly to the previously described cyclic gamma-melanocyte-stimulating hormone (gamma-MSH)-derived hMC3R/hMC5R antagonists. These newly developed melanotropins will serve as critical biochemical tools for elucidating the full spectrum of functions performed by the physiologically important melanocortin-3 receptor.
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MESH Headings
- Binding, Competitive
- Cell Line
- Cyclic AMP/biosynthesis
- Humans
- Lactams/chemical synthesis
- Lactams/pharmacology
- Models, Molecular
- Peptides, Cyclic/chemical synthesis
- Peptides, Cyclic/chemistry
- Peptides, Cyclic/pharmacology
- Radioligand Assay
- Receptor, Melanocortin, Type 3/agonists
- Receptor, Melanocortin, Type 3/antagonists & inhibitors
- Receptor, Melanocortin, Type 3/chemistry
- Structure-Activity Relationship
- alpha-MSH/analogs & derivatives
- alpha-MSH/chemical synthesis
- alpha-MSH/pharmacology
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Affiliation(s)
| | - Minying Cai
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - Erin S. Palmer
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - Matthew M. Dedek
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - James P. Cain
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - April R. Van Scoy
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - Bahar Tan
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - Josef Vagner
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - Dev Trivedi
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
| | - Victor J. Hruby
- Department of Chemistry, University of Arizona, Tucson, Arizona 85721
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Safarinejad MR. RETRACTED: Evaluation of the safety and efficacy of bremelanotide, a melanocortin receptor agonist, in female subjects with arousal disorder: a double-blind placebo-controlled, fixed dose, randomized study. J Sex Med 2007; 5:887-897. [PMID: 18179455 DOI: 10.1111/j.1743-6109.2007.00698.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).
This article has been retracted at the request of the Editor-in-Chief. Following the retraction of Dr. Safarinejad's work by other journals, The Journal of Sexual Medicine has undertaken an extensive re-review of all papers Dr. Safarinejad published with the journal. Following an intensive re-evaluation and close scrutiny of the manuscripts, our expert reviewers raised multiple concerning questions about the methodology, results, and statistical interpretation as presented in this article. Dr. Safarinejad was contacted to provide his original data and offer explanations to address the concerns expressed by the reviewers. Dr Safarinejad chose not to respond. Consequently, we can no longer verify the results or methods as presented and therefore retract the article.
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Affiliation(s)
- Mohammad Reza Safarinejad
- Urology and Nephrology Research Center, Shaheed Beheshti University of Medical Sciences, Tehran, Iran.
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