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Melanocortin activity

Ghazaul Dezfuli, Richard A Gillis, Jaclyn E Tatge, Kimbell R Duncan, Kenneth L Dretchen, Patrick G Jackson, Joseph G Verbalis, Niaz Sahibzada
Background/Objectives: We tested the hypothesis that abolishing vagal nerve activity will reverse the obesity phenotype of melanocortin 4 receptor knockout mice ( Mc4r -/- ). Subjects/Methods: In two separate studies, we examined the efficacy of bilateral subdiaphragmatic vagotomy (SDV) with pyloroplasty in the prevention and treatment of obesity in Mc4r -/- mice. Results: In the first study, SDV prevented >20% increase in body weight (BW) associated with this genotype. This was correlated with a transient reduction in overall food intake (FI) in the preventative arm of the study...
2018: Frontiers in Neuroscience
Robert M Dores, Michelle Scuba-Gray, Bridgette McNally, Perry Davis, Akiyoshi Takahashi
Previous studies on bony vertebrate MC2R orthologs (i.e., ray finned fishes, amphibians, reptiles, birds, and mammals) have shown that these MC2R orthologs have an obligatory requirement for interaction with bony vertebrate MRAP1 orthologs to a) allow for the trafficking of the MC2R ortholog to the plasma membrane; and b) to allow activation by ACTH, but not by any MSH-sized ligand. In addition, previous studies have found that co-expression of teleost and mammalian MC4R orthologs with corresponding MRAP2 has positive effects on sensitivity to stimulation by αMSH or ACTH...
March 7, 2018: General and Comparative Endocrinology
Iain R Tough, Sarah Forbes, Herbert Herzog, Robert M Jones, Thue W Schwartz, Helen M Cox
The lipid sensor GPR119 is highly expressed by enteroendocrine L-cells and pancreatic β-cells that release the hormones, PYY and GLP-1, and insulin, respectively. Endogenous oleoylethanolamide (OEA) and the dietary metabolite, 2-monoacylglycerol (2-OG) can each activate GPR119. Here we compared mucosal responses to selective, synthetic GPR119 agonists (AR440006, AR231453) and the lipids, OEA, 2-OG and N-oleoyldopamine (OLDA) monitoring epithelial ion transport as a read-out for L-cell activity in native mouse and human gastrointestinal (GI) mucosae...
February 19, 2018: Endocrinology
Giuseppe Bruschetta, Sungho Jin, Jung Dae Kim, Sabrina Diano
OBJECTIVE: Prolyl carboxypeptidase (PRCP) plays a role in the regulation of energy metabolism by inactivating hypothalamic α-melanocyte stimulating hormone (α-MSH) levels. Although detected in the arcuate nucleus, limited PRCP expression has been observed in the arcuate POMC neurons, and its site of action in regulating metabolism is still ill-defined. METHODS: We performed immunostaining to assess the localization of PRCP in arcuate Neuropeptide Y/Agouti-related Peptide (NPY/AgRP) neurons...
February 8, 2018: Molecular Metabolism
Norimichi Chiyonobu, Shu Shimada, Yoshimitsu Akiyama, Kaoru Mogushi, Michiko Itoh, Keiichi Akahoshi, Satoshi Matsumura, Kosuke Ogawa, Hiroaki Ono, Yusuke Mitsunori, Daisuke Ban, Atsushi Kudo, Shigeki Arii, Takayoshi Suganami, Shoji Yamaoka, Yoshihiro Ogawa, Minoru Tanabe, Shinji Tanaka
Metabolic syndrome is a newly identified risk factor for hepatocellular carcinoma (HCC); however, tumor-specific biomarkers still remain unclear. We performed cross-species analysis to compare gene signatures of HCC from human patients and melanocortin 4 receptor-knockout (MC4R-KO) mice, which develop HCC with obesity, insulin resistance, and dyslipidemia. Unsupervised hierarchical clustering and principle component analysis of 746 differentially expressed orthologous genes classified HCC of 152 human patients and MC4R-KO mice into two distinct subgroups, one of which included mouse HCC and was etiologically associated with metabolic risk factors...
February 15, 2018: American Journal of Pathology
Aygul Subkhangulova, Anna R Malik, Guido Hermey, Oliver Popp, Gunnar Dittmar, Thomas Rathjen, Matthew N Poy, Alexander Stumpf, Prateep Sanker Beed, Dietmar Schmitz, Tilman Breiderhoff, Thomas E Willnow
SORCS1 and SORCS3 are two related sorting receptors expressed in neurons of the arcuate nucleus of the hypothalamus. Using mouse models with individual or dual receptor deficiencies, we document a previously unknown function of these receptors in central control of metabolism. Specifically, SORCS1 and SORCS3 act as intracellular trafficking receptors for tropomyosin-related kinase B to attenuate signaling by brain-derived neurotrophic factor, a potent regulator of energy homeostasis. Loss of the joint action of SORCS1 and SORCS3 in mutant mice results in excessive production of the orexigenic neuropeptide agouti-related peptide and in a state of chronic energy excess characterized by enhanced food intake, decreased locomotor activity, diminished usage of lipids as metabolic fuel, and increased adiposity, albeit at overall reduced body weight...
February 12, 2018: EMBO Reports
Irina V Romanova, Kira V Derkach, Anastasiya L Mikhrina, Ivan B Sukhov, Elena V Mikhailova, Alexander O Shpakov
The pro-opiomelanocortin (POMC)-expressing neurons of the hypothalamic arcuate nucleus (ARC) are involved in the control of food intake and metabolic processes. It is assumed that, in addition to leptin, the activity of these neurons is regulated by serotonin and dopamine, but only subtype 2C serotonin receptors (5-HT2CR) was identified earlier on the POMC-neurons. The aim of this work was a comparative study of the localization and number of leptin receptors (LepR), types 1 and 2 dopamine receptors (D1R, D2R), 5-HT1BR and 5-HT2CR on the POMC-neurons and the expression of the genes encoding them in the ARC of the normal and diet-induced obese (DIO) rodents and the agouti mice (A y /a) with the melanocortin obesity...
February 3, 2018: Neurochemical Research
Susanne Grässel, Dominique Muschter
Joint tissues like synovium, articular cartilage, meniscus and subchondral bone, are targets for neuropeptides. Resident cells of these tissues express receptors for various neuroendocrine-derived peptides including proopiomelanocortin (POMC)-derived peptides, i.e., α-melanocyte-stimulating hormone (α-MSH), adrenocorticotropin (ACTH) and β-endorphin (β-ED), and sympathetic neuropeptides like vasoactive intestinal peptide (VIP) and neuropeptide y (NPY). Melanocortins attained particular attention due to their immunomodulatory and anti-inflammatory effects in several tissues and organs...
January 26, 2018: International Journal of Molecular Sciences
Katlyn A Fleming, Mark D Ericson, Katie T Freeman, Danielle N Adank, Mary M Lunzer, Stacey L Wilber, Carrie Haskell-Luevano
The melanocortin system has five receptors and antagonists of the central melanocortin receptors (MC3R, MC4R) are postulated to be viable therapeutics for disorders of negative energy balance such as anorexia, cachexia, and failure to thrive. Agouti-related protein (AGRP) is an antagonist of the MC3R and an antagonist/inverse agonist of the MC4R. Biophysical NMR based structural studies have demonstrated that the active sequence of this hormone, Arg-Phe-Phe, is located on an exposed β-hairpin loop. It has previously been demonstrated that the macrocyclic octapeptide scaffold c[Pro1-Arg2-Phe3-Phe4-Asn5-Ala6-Phe7-DPro8] is 16-fold less potent than AGRP at the mMC4R...
January 24, 2018: ACS Chemical Neuroscience
Makoto Habara, Nobuko Mori, Yuki Okada, Koh Kawasumi, Nobuhiro Nakao, Yoshikazu Tanaka, Toshiro Arai, Ichiro Yamamoto
Melanocortin 4 receptor (MC4R), which is a member of the G protein-coupled receptor (GPCR) family, mediates regulation of energy homeostasis upon the binding of α-melanocyte-stimulating hormone (α-MSH) in the central nervous system (CNS). Melanocortin 2 receptor accessory protein 2 (MRAP2) modulates the function of MC4R. We performed cDNA cloning of cat MC4R and MRAP2 and characterized their amino acid sequences, mRNA expression patterns in cat tissues, protein-protein interactions, and functions. We found high sequence homology (>88%) with other mammalian MC4R and MRAP2 encoding 332 and 206 amino acid residues, respectively...
January 19, 2018: General and Comparative Endocrinology
Alexandre A da Silva, John Nathan Freeman, John E Hall, Jussara M do Carmo
Although central melanocortin 4 receptor (MC4R) blockade abolishes the CNS-mediated anorexogenic, antidiabetic and cardiovascular actions of leptin, chronic MC4R stimulation fails to completely mimic leptin's effects. Because neuropeptide Y (NPY) and MC4R exert opposite effects on cardiovascular and metabolic functions, we tested its role in offsetting the long-term actions of MC4R activation. Wild-type (WT) and NPY-deficient (NPY-/-) mice were implanted with telemetry probes for measuring mean arterial pressure (MAP) and heart rate (HR) 24-h/d...
December 20, 2017: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
Sang Hyeon Ju, Gyu-Bon Cho, Jong-Woo Sohn
It is well known that melanocortin-4 receptors (MC4Rs) and central melanocortin pathways regulate food intake, energy expenditure, and glucose homeostasis. Importantly, MC4R deficiency is the most common monogenic cause of human obesity. Interestingly, MC4Rs expressed by distinct central nuclei are responsible for the different physiological function of MC4R stimulation. In addition, MC4Rs activate multiple intracellular and/or synaptic signaling molecules for the regulation of neuronal circuits. Therefore, MC4Rs and the downstream signal molecules are plausible targets for development of novel therapeutics against obesity and obesity-related metabolic disorders...
January 9, 2018: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
Salla Nuutinen, Liisa Ailanen, Eriika Savontaus, Petteri Rinne
Atherosclerosis is a chronic inflammatory disease of the arteries. The disease is initiated by endothelial dysfunction that allows the transport of leukocytes and low-density lipoprotein into the vessel wall forming atherosclerotic plaques. The melanocortin system is an endogenous peptide system that regulates, for example, energy homeostasis and cardiovascular function. Melanocortin treatment with endogenous or synthetic melanocortin peptides reduces body weight, protects the endothelium and alleviates vascular inflammation, but the long-term effects of melanocortin system activation on atheroprogression remain largely unknown...
January 9, 2018: Journal of Endocrinology
Małgorzata Szkup, Aleksander Jerzy Owczarek, Daria Schneider-Matyka, Jacek Brodowski, Beata Łój, Elżbieta Grochans
INTRODUCTION: Metabolic syndrome (MetS) is regarded as a set of abnormalities, increasing the risk of serious functioning disorders. It can develop as a result of genetic predisposition. AIM: The aim of this study was to establish associations between MetS-related abnormalities and the PPAR-γ rs1801282, FTO rs9939609, and MC4R rs17782313 polymorphisms. MATERIAL AND METHODS: The study involved 425 women aged 45-60 years. The participants were surveyed and subjected to anthropometric, biochemical and genetic analysis...
January 9, 2018: Aging
K V Derkach, I O Zakharova, I V Romanova, I I Zorina, A L Mikhrina, A O Shpakov
The metabolic parameters and functional state of hypothalamic systems in mice with the Yellow mutation in the Agouti locus and with obesity of the melanocortin type and the effect of metformin (MF) treatment (9 days, 200 mg/kg/day) were studied. The MF treatment led to decreased body weight and to normalization of glucose tolerance in mice. In the hypothalamus, MF restored the decreased activity of Akt kinase, the main component of leptin pathway, and normalized the increased expression of subtype 1B serotonin receptor...
November 2017: Doklady. Biochemistry and Biophysics
Shunmei Liu, Genevieve Marcelin, Clemence Blouet, Jae Hoon Jeong, Young-Hwan Jo, Gary J Schwartz, Streamson Chua
OBJECTIVE: Bile acids have been implicated as important regulators of glucose metabolism via activation of FXR and GPBAR1. We have previously shown that FGF19 can modulate glucose handling by suppressing the activity of hypothalamic AGRP/NPY neurons. As bile acids stimulate the release of FGF19/FGF15 into the circulation, we pursued the potential of bile acids to improve glucose tolerance via a gut-brain axis involving FXR and FGF15/FGF19 within enterocytes and FGF receptors on hypothalamic AGRP/NPY neurons...
December 9, 2017: Molecular Metabolism
Ryogo Shobatake, Ken Takasawa, Hiroyo Ota, Asako Itaya-Hironaka, Akiyo Yamauchi, Sumiyo Sakuramoto-Tsuchida, Tomoko Uchiyama, Mai Makino, Kazuma Sugie, Shin Takasawa, Satoshi Ueno
Sleep apnea syndrome (SAS) is characterized by intermittent hypoxia (IH) during sleep. SAS and obesity are strongly related to each other. Here, we investigated the effect of IH on the expression of major appetite regulatory genes in human neuronal cells. We exposed NB-1, SH-SY5Y, and SK-N-SH human neuronal cells to IH (64 cycles of 5 min hypoxia and 10 min normoxia), normoxia, or sustained hypoxia for 24 h and measured the mRNA levels of proopiomelanocortin (POMC), cocaine- and amphetamine-regulated transcript (CART), galanin, galanin-like peptide, ghrelin, pyroglutamylated RFamide peptide, agouti-related peptide, neuropeptide Y, and melanocortin 4 receptor by real-time RT-PCR...
December 21, 2017: International Journal of Biochemistry & Cell Biology
M M Lei, C K Wei, Z Chen, S Yosefi, H X Zhu, Z D Shi
Antibodies against the extracellular domains of the chicken leptin receptor were used to study the biological function of leptin in growing chickens. Both polyclonal and monoclonal antibodies were administered intramuscularly to 30-d-old Chinese indigenous Gushi pullets. Both antibody preparations increased feed intake for 6 h after injection and reduced plasma concentrations of glucose, triglycerides, and both high- and low-density lipoproteins. The antibody treatments also upregulated agouti-related peptide and neuropeptide Y in the hypothalamus and downregulated proopiomelanocortin, melanocortin 4 receptor, and leptin receptor...
December 13, 2017: General and Comparative Endocrinology
Kathleen G Mountjoy, Alexandre Caron, Kristina Hubbard, Avik Shome, Angus C Grey, Bo Sun, Sarah Bould, Martin Middleditch, Beau Pontré, Ailsa McGregor, Paul W R Harris, Renata Kowalczyk, Margaret A Brimble, Rikus Botha, Karen M L Tan, Sarah J Piper, Christina Buchanan, Syann Lee, Anthony P Coll, Joel K Elmquist
OBJECTIVE: Regulation of energy balance depends on pro-opiomelanocortin (POMC)-derived peptides and melanocortin-4 receptor (MC4R). Alpha-melanocyte stimulating hormone (α-MSH) is the predicted natural POMC-derived peptide that regulates energy balance. Desacetyl-α-MSH, the precursor for α-MSH, is present in brain and blood. Desacetyl-α-MSH is considered to be unimportant for regulating energy balance despite being more potent (compared with α-MSH) at activating the appetite-regulating MC4R in vitro...
March 2018: Molecular Metabolism
Xiaodong Zhang, Alicia M Saarinen, Latoya E Campbell, Elena A De Filippis, Jun Liu
Melanocortin 2 receptor accessory protein (MRAP) is highly expressed in adrenal gland and adipose tissue. In adrenal cells, MRAP is essential for adrenocorticotropic hormone (ACTH)-induced activation of the cAMP/protein kinase A (PKA) pathway by melanocortin 2 receptor (MC2R), leading to glucocorticoid production and secretion. Although ACTH was known to stimulate PKA-dependent lipolysis, the functional involvement of MRAP in adipocyte metabolism remains incompletely defined. Herein, we found that knockdown or overexpression of MRAP in 3T3-L1 adipocytes reduced or increased ACTH-induced lipolysis, respectively...
February 2018: Diabetes
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