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Mun SH, Hwang CS. Marchf6: A guardian against cytosol-spilled POMC-induced ferroptosis. Mol Cells 2024; 47:100008. [PMID: 38215826 PMCID: PMC10960111 DOI: 10.1016/j.mocell.2024.100008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/02/2024] [Indexed: 01/14/2024] Open
Affiliation(s)
- Sang-Hyeon Mun
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea
| | - Cheol-Sang Hwang
- Department of Life Sciences, Korea University, Seoul 02841, Republic of Korea.
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2
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Brings S, Mier W, Beijer B, Kliemank E, Herzig S, Szendroedi J, Nawroth PP, Fleming T. Non-cross-linking advanced glycation end products affect prohormone processing. Biochem J 2024; 481:33-44. [PMID: 38112318 DOI: 10.1042/bcj20230321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 12/01/2023] [Accepted: 12/19/2023] [Indexed: 12/21/2023]
Abstract
Advanced glycation end products (AGEs) are non-enzymatic post-translational modifications of amino acids and are associated with diabetic complications. One proposed pathomechanism is the impaired processing of AGE-modified proteins or peptides including prohormones. Two approaches were applied to investigate whether substrate modification with AGEs affects the processing of substrates like prohormones to the active hormones. First, we employed solid-phase peptide synthesis to generate unmodified as well as AGE-modified protease substrates. Activity of proteases towards these substrates was quantified. Second, we tested the effect of AGE-modified proinsulin on the processing to insulin. Proteases showed the expected activity towards the unmodified peptide substrates containing arginine or lysine at the C-terminal cleavage site. Indeed, modification with Nε-carboxymethyllysine (CML) or methylglyoxal-hydroimidazolone 1 (MG-H1) affected all proteases tested. Cysteine cathepsins displayed a reduction in activity by ∼50% towards CML and MG-H1 modified substrates. The specific proteases trypsin, proprotein convertases subtilisin-kexins (PCSKs) type proteases, and carboxypeptidase E (CPE) were completely inactive towards modified substrates. Proinsulin incubation with methylglyoxal at physiological concentrations for 24 h resulted in the formation of MG-modified proinsulin. The formation of insulin was reduced by up to 80% in a concentration-dependent manner. Here, we demonstrate the inhibitory effect of substrate-AGE modifications on proteases. The finding that PCSKs and CPE, which are essential for prohormone processing, are inactive towards modified substrates could point to a yet unrecognized pathomechanism resulting from AGE modification relevant for the etiopathogenesis of diabetes and the development of obesity.
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Affiliation(s)
- Sebastian Brings
- Department of Endocrinology, Metabolism and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
- Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Walter Mier
- Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Barbro Beijer
- Department of Nuclear Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Elisabeth Kliemank
- Department of Endocrinology, Metabolism and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
| | - Stephan Herzig
- German Centre of Diabetes Research (DZD), Munich, Germany
- Institute for Diabetes and Cancer IDC Helmholtz Center Munich and Joint Heidelberg-IDC Translational Diabetes Program, Munich, Germany
| | - Julia Szendroedi
- Department of Endocrinology, Metabolism and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
- German Centre of Diabetes Research (DZD), Munich, Germany
- Institute for Diabetes and Cancer IDC Helmholtz Center Munich and Joint Heidelberg-IDC Translational Diabetes Program, Munich, Germany
- Center for Molecular Biology Heidelberg (ZMBH), Heidelberg, Germany
- Joint Division Molecular Metabolic Control, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Peter P Nawroth
- Department of Immunology, University Hospital Heidelberg, Heidelberg, Germany
| | - Thomas Fleming
- Department of Endocrinology, Metabolism and Clinical Chemistry, University Hospital Heidelberg, Heidelberg, Germany
- German Centre of Diabetes Research (DZD), Munich, Germany
- Institute for Diabetes and Cancer IDC Helmholtz Center Munich and Joint Heidelberg-IDC Translational Diabetes Program, Munich, Germany
- Center for Molecular Biology Heidelberg (ZMBH), Heidelberg, Germany
- Joint Division Molecular Metabolic Control, German Cancer Research Center (DKFZ), Heidelberg, Germany
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3
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Concepción-Zavaleta MJ, Quiroz-Aldave JE, Durand-Vásquez MDC, Gamarra-Osorio ER, Valencia de la Cruz JDC, Barrueto-Callirgos CM, Puelles-León SL, Alvarado-León EDJ, Leiva-Cabrera F, Zavaleta-Gutiérrez FE, Concepción-Urteaga LA, Paz-Ibarra J. A comprehensive review of genetic causes of obesity. World J Pediatr 2024; 20:26-39. [PMID: 37725322 DOI: 10.1007/s12519-023-00757-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 08/16/2023] [Indexed: 09/21/2023]
Abstract
BACKGROUND Obesity is a multifactorial chronic disease with a high, increasing worldwide prevalence. Genetic causes account for 7% of the cases in children with extreme obesity. DATA SOURCES This narrative review was conducted by searching for papers published in the PubMed/MEDLINE, Embase and SciELO databases and included 161 articles. The search used the following search terms: "obesity", "obesity and genetics", "leptin", "Prader-Willi syndrome", and "melanocortins". The types of studies included were systematic reviews, clinical trials, prospective cohort studies, cross-sectional and prospective studies, narrative reviews, and case reports. RESULTS The leptin-melanocortin pathway is primarily responsible for the regulation of appetite and body weight. However, several important aspects of the pathophysiology of obesity remain unknown. Genetic causes of obesity can be grouped into syndromic, monogenic, and polygenic causes and should be assessed in children with extreme obesity before the age of 5 years, hyperphagia, or a family history of extreme obesity. A microarray study, an analysis of the melanocortin type 4 receptor gene mutations and leptin levels should be performed for this purpose. There are three therapeutic levels: lifestyle modifications, pharmacological treatment, and bariatric surgery. CONCLUSIONS Genetic study technologies are in constant development; however, we are still far from having a personalized approach to genetic causes of obesity. A significant proportion of the affected individuals are associated with genetic causes; however, there are still barriers to its approach, as it continues to be underdiagnosed. Video Abstract (MP4 1041807 KB).
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - José Paz-Ibarra
- Department of Medicine, School of Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru
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Stewart AJ, Ireland JL, Durham AE, McGowan CM. Diagnosis of equine pituitary pars intermedia dysfunction. Vet J 2023; 300-302:106036. [PMID: 37805159 DOI: 10.1016/j.tvjl.2023.106036] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 09/25/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Equine pituitary pars intermedia dysfunction (PPID) is common in aged horses. The majority of horses respond well to treatment, but treatment is lifelong, meaning accurate diagnosis of PPID is important. Similar to any condition, there is no perfect laboratory test to diagnose PPID and accuracy is affected by the characteristics of the population in which the test is being evaluated. This review details the importance of consideration of clinical factors and diagnostic test accuracy. Basal adrenocorticotrophic hormone (ACTH) concentration is used most frequently in practice and has very good diagnostic accuracy when used in combination with clinical judgement and the correct application of diagnostic thresholds. The thyrotropin-releasing hormone stimulation test can be used in horses with equivocal test results following basal ACTH testing, or to evaluate subtle cases due to its improved accuracy.
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Affiliation(s)
| | - Joanne L Ireland
- School of Veterinary Science, Faculty of Health and Life Sciences, The University of Liverpool, Neston CH64 7TE, UK
| | - Andy E Durham
- Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK
| | - Catherine M McGowan
- School of Veterinary Science, Faculty of Health and Life Sciences, The University of Liverpool, Neston CH64 7TE, UK.
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5
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Romanova IV, Mikhailova EV, Mikhrina AL, Shpakov AO. Type 1 melanocortin receptors in pro-opiomelanocortin-, vasopressin-, and oxytocin-immunopositive neurons in different areas of mouse brain. Anat Rec (Hoboken) 2023; 306:2388-2399. [PMID: 35475324 DOI: 10.1002/ar.24934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 03/24/2022] [Accepted: 04/04/2022] [Indexed: 10/18/2022]
Abstract
Information on the localization of the Type 1 melanocortin receptors (MC1Rs) in different regions of the brain is very scarce. As a result, the role of MC1Rs in the functioning of brain neurons and in the central regulation of physiological functions has not been studied. This work aimed to study the expression and distribution of MС1Rs in different brain areas of female C57Bl/6J mice. Using real-time polymerase chain reaction, we demonstrated the Mс1R gene expression in the cerebral cortex, midbrain, hypothalamus, medulla oblongata, and hippocampus. Using an immunohistochemical approach, we showed the MС1R localization in neurons of the hypothalamic arcuate, paraventricular and supraoptic nuclei, nucleus tractus solitarius (NTS), dorsal hippocampus, substantia nigra, and cerebral cortex. Using double immunolabeling, the MC1Rs were visualized on the surface and in the bodies and outgrowths of pro-opiomelanocortin (POMC)-immunopositive neurons in the hypothalamic arcuate nucleus, NTS, hippocampal CA3 and CA1 regions, and cerebral cortex. Co-localization with POMC indicates that MC1R, like MC3R, is able to function as an autoreceptor. In the paraventricular and supraoptic nuclei, MC1Rs were visualized on the surface and in the cell bodies of vasopressin- and oxytocin-immunopositive neurons, indicating a relationship between hypothalamic MC1R signaling and vasopressin and oxytocin production. The data obtained indicate a wide distribution of MC1Rs in different areas of the mouse brain and their localization in POMC-, vasopressin- and oxytocin-immunopositive neurons, which may indicate the participation of MC1Rs in the control of many physiological processes in the central nervous system.
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Affiliation(s)
- Irina V Romanova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Elena V Mikhailova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Anastasiya L Mikhrina
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Alexander O Shpakov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
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Luo H, Jiao Q, Shen C, Shao C, Xie J, Chen Y, Feng X, Zhang X. Unraveling the roles of endoplasmic reticulum-associated degradation in metabolic disorders. Front Endocrinol (Lausanne) 2023; 14:1123769. [PMID: 37455916 PMCID: PMC10339828 DOI: 10.3389/fendo.2023.1123769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 06/19/2023] [Indexed: 07/18/2023] Open
Abstract
Misfolded proteins retained in the endoplasmic reticulum cause many human diseases. ER-associated degradation (ERAD) is one of the protein quality and quantity control system located at ER, which is responsible for translocating the misfolded proteins or properly folded but excess proteins out of the ER for proteasomal degradation. Recent studies have revealed that mice with ERAD deficiency in specific cell types exhibit impaired metabolism homeostasis and metabolic diseases. Here, we highlight the ERAD physiological functions in metabolic disorders in a substrate-dependent and cell type-specific manner.
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Affiliation(s)
- Hui Luo
- *Correspondence: Hui Luo, ; Xingwei Zhang,
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7
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Novelli G, Cassadonte C, Sbraccia P, Biancolella M. Genetics: A Starting Point for the Prevention and the Treatment of Obesity. Nutrients 2023; 15:2782. [PMID: 37375686 DOI: 10.3390/nu15122782] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Obesity is a common, serious, and costly disease. More than 1 billion people worldwide are obese-650 million adults, 340 million adolescents, and 39 million children. The WHO estimates that, by 2025, approximately 167 million people-adults and children-will become less healthy because they are overweight or obese. Obesity-related conditions include heart disease, stroke, type 2 diabetes, and certain types of cancer. These are among the leading causes of preventable, premature death. The estimated annual medical cost of obesity in the United States was nearly $173 billion in 2019 dollars. Obesity is considered the result of a complex interaction between genes and the environment. Both genes and the environment change in different populations. In fact, the prevalence changes as the result of eating habits, lifestyle, and expression of genes coding for factors involved in the regulation of body weight, food intake, and satiety. Expression of these genes involves different epigenetic processes, such as DNA methylation, histone modification, or non-coding micro-RNA synthesis, as well as variations in the gene sequence, which results in functional alterations. Evolutionary and non-evolutionary (i.e., genetic drift, migration, and founder's effect) factors have shaped the genetic predisposition or protection from obesity in modern human populations. Understanding and knowing the pathogenesis of obesity will lead to prevention and treatment strategies not only for obesity, but also for other related diseases.
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Affiliation(s)
- Giuseppe Novelli
- Department of Biomedicine and Prevention, Medical School, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
- Italian Barometer Diabetes Observatory Foundation, IBDO, 00186 Rome, Italy
- Department of Pharmacology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Carmen Cassadonte
- Department of Biomedicine and Prevention, Medical School, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Paolo Sbraccia
- Italian Barometer Diabetes Observatory Foundation, IBDO, 00186 Rome, Italy
- Department of Systems Medicine, Medical School, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Michela Biancolella
- Department of Biology, Tor Vergata University of Rome, Via della Ricerca Scientifica 1, 00133 Rome, Italy
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Martins MG, Silver Z, Ayoub K, Hyland L, Woodside B, Kiss ACI, Abizaid A. Maternal glucose intolerance during pregnancy affects offspring POMC expression and results in adult metabolic alterations in a sex-dependent manner. Front Endocrinol (Lausanne) 2023; 14:1189207. [PMID: 37396180 PMCID: PMC10311085 DOI: 10.3389/fendo.2023.1189207] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 05/23/2023] [Indexed: 07/04/2023] Open
Abstract
Introduction Gestational diabetes (GDM) is associated with negative outcomes in mothers and their offspring, including greater risks of macrosomia at birth and the development of metabolic disorders. While these outcomes are well-established, the mechanisms by which this increased metabolic vulnerability is conferred on the offspring are comparatively lacking. One proposed mechanism is that maternal glycemic dysregulation alters the development of the hypothalamic regions related to metabolism and energy balance. Methods To investigate this possibility, in this study, we first examined the effects of STZ-induced maternal glucose intolerance on the offspring on pregnancy day (PD) 19, and, in a second experiment, in early adulthood (postnatal day (PND) 60). Whether effects would be influenced by sex, or exposure of offspring to a high-fat diet was also investigated. The impact of maternal STZ treatment on POMC neuron number in the ARC of offspring at both time points was also examined. Results As expected, STZ administration on PD 7 decreased maternal glucose tolerance, and increased risk for macrosomia, and loss of pups at birth. Offspring of STZ-treated mothers were also more vulnerable to developing metabolic impairments in adulthood. These were accompanied by sex-specific effects of maternal STZ treatment in the offspring, including fewer POMC neurons in the ARC of female but not male infants in late pregnancy and a higher number of POMC neurons in the ARC of both male and female adult offspring of STZ-treated dams, which was exacerbated in females exposed to a high-fat diet after weaning. Discussion This work suggests that maternal hyperglycemia induced by STZ treatment, in combination with early-life exposure to an obesogenic diet, leads to adult metabolic alterations that correlate with the increased hypothalamic expression of POMC, showing that maternal glycemic dysregulation can impact the development of hypothalamic circuits regulating energy state with a stronger impact on female offspring.
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Affiliation(s)
- Marina Galleazzo Martins
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
- Department of Physiology, Institute of Biosciences of the University of São Paulo (IB/USP), São Paulo, São Paulo, Brazil
| | - Zachary Silver
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Kiara Ayoub
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Lindsay Hyland
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Barbara Woodside
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
| | - Ana Carolina Inhasz Kiss
- Department of Physiology, Institute of Biosciences of the University of São Paulo (IB/USP), São Paulo, São Paulo, Brazil
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (Unesp), Botucatu, São Paulo, Brazil
| | - Alfonso Abizaid
- Department of Neuroscience, Carleton University, Ottawa, ON, Canada
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Clemente-Suárez VJ, Redondo-Flórez L, Beltrán-Velasco AI, Martín-Rodríguez A, Martínez-Guardado I, Navarro-Jiménez E, Laborde-Cárdenas CC, Tornero-Aguilera JF. The Role of Adipokines in Health and Disease. Biomedicines 2023; 11:biomedicines11051290. [PMID: 37238961 DOI: 10.3390/biomedicines11051290] [Citation(s) in RCA: 42] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/21/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023] Open
Abstract
Adipokines are cell-signaling proteins secreted by adipose tissue that has been related to a low-grade state of inflammation and different pathologies. The present review aims to analyze the role of adipokines in health and disease in order to understand the important functions and effects of these cytokines. For this aim, the present review delves into the type of adipocytes and the cytokines produced, as well as their functions; the relations of adipokines in inflammation and different diseases such as cardiovascular, atherosclerosis, mental diseases, metabolic disorders, cancer, and eating behaviors; and finally, the role of microbiota, nutrition, and physical activity in adipokines is discussed. This information would allow for a better understanding of these important cytokines and their effects on body organisms.
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Affiliation(s)
| | - Laura Redondo-Flórez
- Department of Health Sciences, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, C/Tajo s/n, 28670 Madrid, Spain
| | - Ana Isabel Beltrán-Velasco
- Department of Psychology, Faculty of Life and Natural Sciences, University of Nebrija, C/del Hostal, 28248 Madrid, Spain
| | | | - Ismael Martínez-Guardado
- BRABE Group, Department of Psychology, Faculty of Life and Natural Sciences, University of Nebrija, C/del Hostal, 28248 Madrid, Spain
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10
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Loss of hypothalamic Furin affects POMC to proACTH cleavage and feeding behavior in high-fat diet-fed mice. Mol Metab 2022; 66:101627. [PMID: 36374777 PMCID: PMC9664468 DOI: 10.1016/j.molmet.2022.101627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/23/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVE The hypothalamus regulates feeding and glucose homeostasis through the balanced action of different neuropeptides, which are cleaved and activated by the proprotein convertases PC1/3 and PC2. However, the recent association of polymorphisms in the proprotein convertase FURIN with type 2 diabetes, metabolic syndrome, and obesity, prompted us to investigate the role of FURIN in hypothalamic neurons controlling glucose and feeding. METHODS POMC-Cre+/- mice were bred with Furinfl/fl mice to generate conditional knockout mice with Furin-deletion in neurons expressing proopiomelanocortin (POMCFurKO), and Furinfl/fl mice were used as controls. POMCFurKO and controls were periodically monitored on both normal chow diet and high fat diet (HFD) for body weight and glucose tolerance by established in-vivo procedures. Food intake was measured in HFD-fed FurKO and controls. Hypothalamic Pomc mRNA was measured by RT-qPCR. ELISAs quantified POMC protein and resulting peptides in the hypothalamic extracts of POMCFurKO mice and controls. The in-vitro processing of POMC was studied by biochemical techniques in HEK293T and CHO cell lines lacking FURIN. RESULTS In control mice, Furin mRNA levels were significantly upregulated on HFD feeding, suggesting an increased demand for FURIN activity in obesogenic conditions. Under these conditions, the POMCFurKO mice were hyperphagic and had increased body weight compared to Furinfl/fl mice. Moreover, protein levels of POMC were elevated and ACTH concentrations markedly reduced. Also, the ratio of α-MSH/POMC was decreased in POMCFurKO mice compared to controls. This indicates that POMC processing was significantly reduced in the hypothalami of POMCFurKO mice, highlighting for the first time the involvement of FURIN in the cleavage of POMC. Importantly, we found that in vitro, the first stage in processing where POMC is cleaved into proACTH was achieved by FURIN but not by PC1/3 or the other proprotein convertases in cell lines lacking a regulated secretory pathway. CONCLUSIONS These results suggest that FURIN processes POMC into proACTH before sorting into the regulated secretory pathway, challenging the dogma that PC1/3 and PC2 are the only convertases responsible for POMC cleavage. Furthermore, its deletion affects feeding behaviors under obesogenic conditions.
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11
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Regulated processing and secretion of a peptide precursor in cilia. Proc Natl Acad Sci U S A 2022; 119:e2206098119. [PMID: 35878031 PMCID: PMC9351486 DOI: 10.1073/pnas.2206098119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Cilia are sensory and secretory organelles that both receive information from the environment and transmit signals. Cilia-derived vesicles (ectosomes), formed by outward budding of the ciliary membrane, carry enzymes and other bioactive products; this process represents an ancient mode of regulated secretion. Peptidergic intercellular communication controls a wide range of physiological and behavioral responses and occurs throughout eukaryotes. The Chlamydomonas reinhardtii genome encodes what appear to be numerous prepropeptides and enzymes homologous to those used to convert metazoan prepropeptides into bioactive peptide products. Since C. reinhardtii, a green alga, lack the dense core vesicles in which metazoan peptides are processed and stored, we explored the hypothesis that propeptide processing and secretion occur through the regulated release of ciliary ectosomes. A synthetic peptide (GATI-amide) that could be generated from a 91-kDa peptide precursor (proGATI) serves as a chemotactic modulator, attracting minus gametes while repelling plus gametes. Here we dissect the processing pathway that leads to formation of an amidated peptidergic sexual signal specifically on the ciliary ectosomes of plus gametes. Unlike metazoan propeptides, modeling studies identified stable domains in proGATI. Mass spectrometric analysis of a potential prohormone convertase and the amidated proGATI-derived products found in cilia and mating ectosomes link endoproteolytic cleavage to ectosome entry. Extensive posttranslational modification of proGATI confers stability to its amidated product. Analysis of this pathway affords insight into the evolution of peptidergic signaling; this will facilitate studies of the secretory functions of metazoan cilia.
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12
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Mikhailova EV, Derkach KV, Shpakov AO, Romanova IV. Melanocortin 1 Receptors in the Hypothalamus of Mice within the Norm and in Diet-Induced Obesity. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022040263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Goit RK, Taylor AW, Yin Lo AC. The central melanocortin system as a treatment target for obesity and diabetes: A brief overview. Eur J Pharmacol 2022; 924:174956. [DOI: 10.1016/j.ejphar.2022.174956] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 04/01/2022] [Accepted: 04/11/2022] [Indexed: 12/12/2022]
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14
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Shakya M, Martin NK, Arunagiri A, Martin MG, Arvan P, Low MJ, Lindberg I. The G209R mutant mouse as a model for human PCSK1 polyendocrinopathy. Endocrinology 2022; 163:6542675. [PMID: 35245347 PMCID: PMC9044177 DOI: 10.1210/endocr/bqac024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Indexed: 11/19/2022]
Abstract
PCSK1 encodes an enzyme required for prohormone maturation into bioactive peptides. A striking number of SNPs and rare mutations in PCSK1 are associated with a range of clinical phenotypes. Infants bearing two copies of a catalytically inactivating mutation, such as G209R, exhibit life-threatening chronic diarrhea and subsequently develop systemic endocrinopathies. Using CRISPR/Cas9 technology, we have engineered a mouse model bearing a G209R missense mutation in exon 6 of the murine Pcsk1 locus. Most pups homozygous for the G209R mutation succumbed by day 2, and surviving pups were severely dwarfed. In homozygous (but not heterozygous) pups, blood glucose levels were significantly lower, accompanied by elevated plasma insulin-like immunoreactivity and accumulation of large quantities of unprocessed proinsulin in the pancreas. Peptide hormone processing was also aberrant in G209R mouse pituitary, with mature ACTH levels markedly reduced in homozygotes, accompanied by a significant accumulation of POMC. We also observed a significant reduction in PC1/3 protein in the brains of G209R homozygous mice by Western blotting, while PC2 levels remained unaffected. Most likely due to the continued presence of PC2, pituitary and brain levels of α-MSH were not impaired. Analysis of intestinal cell types indicated a modest reduction of enteroendocrine cells in G209R homozygotes. We suggest that the G209R Pcsk1 mouse model recapitulates many of the dramatic neonatal deficiencies of human patients with this homozygous mutation.
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Affiliation(s)
- Manita Shakya
- Department of Anatomy & Neurobiology, University of Maryland School of
Medicine, Baltimore, MD, USA
| | - Surbhi
- Department Molecular & Integrative Physiology, University of
Michigan, Ann Arbor, MI, USA
| | - Nicolle K Martin
- Department of Pediatrics, Division of Gastroenterology and Nutrition, Mattel
Children’s Hospital and the David Geffen School of Medicine, University of California Los
Angeles, Los Angeles, CA, USA
| | - Anoop Arunagiri
- Division of Metabolism, Endocrinology & Diabetes, University of
Michigan, Ann Arbor, MI, USA
| | - Martin G Martin
- Department of Pediatrics, Division of Gastroenterology and Nutrition, Mattel
Children’s Hospital and the David Geffen School of Medicine, University of California Los
Angeles, Los Angeles, CA, USA
| | - Peter Arvan
- Division of Metabolism, Endocrinology & Diabetes, University of
Michigan, Ann Arbor, MI, USA
| | - Malcolm J Low
- Department Molecular & Integrative Physiology, University of
Michigan, Ann Arbor, MI, USA
| | - Iris Lindberg
- Department of Anatomy & Neurobiology, University of Maryland School of
Medicine, Baltimore, MD, USA
- Correspondence: Iris Lindberg, PhD, Department of Anatomy and Neurobiology, University of Maryland
School of Medicine, 20 Penn St, HSF2, S218, Baltimore, MD 21201, USA.
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Hypothalamic expression of huntingtin causes distinct metabolic changes in Huntington's disease mice. Mol Metab 2022; 57:101439. [PMID: 35007790 PMCID: PMC8814380 DOI: 10.1016/j.molmet.2022.101439] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 01/05/2022] [Indexed: 11/29/2022] Open
Abstract
Objective In Huntington's disease (HD), the disease-causing huntingtin (HTT) protein is ubiquitously expressed and causes both central and peripheral pathology. In clinical HD, a higher body mass index has been associated with slower disease progression, indicating the role of metabolic changes in disease pathogenesis. Underlying mechanisms of metabolic changes in HD remain poorly understood, but recent studies suggest the involvement of hypothalamic dysfunction. The present study aimed to investigate whether modulation of hypothalamic HTT levels would affect metabolic phenotype and disease features in HD using mouse models. Methods We used the R6/2 and BACHD mouse models that express different lengths of mutant HTT to develop lean- and obese phenotypes, respectively. We utilized adeno-associated viral vectors to overexpress either mutant or wild-type HTT in the hypothalamus of R6/2, BACHD, and their wild-type littermates. The metabolic phenotype was assessed by body weight measurements over time and body composition analysis using dual-energy x-ray absorptiometry at the endpoint. R6/2 mice were further characterized using behavioral analyses, including rotarod, nesting-, and hindlimb clasping tests during early- and late-time points of disease progression. Finally, gene expression analysis was performed in R6/2 mice and wild-type littermates in order to assess transcriptional changes in the hypothalamus and adipose tissue. Results Hypothalamic overexpression of mutant HTT induced significant gender-affected body weight gain in all models, including wild-type mice. In R6/2 females, early weight gain shifted to weight loss during the corresponding late stage of disease despite increased fat accumulation. Body weight changes were accompanied by behavioral alterations. During the period of early weight gain, R6/2 mice displayed a comparable locomotor capacity to wild-type mice. When assessing behavior just prior to weight loss onset in R6/2 mice, decreased locomotor performance was observed in R6/2 females with hypothalamic overexpression of mutant HTT. Transcriptional downregulation of beta-3 adrenergic receptor (B3AR), adipose triglyceride lipase (ATGL), and peroxisome proliferator-activated receptor-gamma (PPARγ) in gonadal white adipose tissue was accompanied by distinct alterations in hypothalamic gene expression profiles in R6/2 females after mutant HTT overexpression. No significant effect on metabolic phenotype in R6/2 was seen in response to wild-type HTT overexpression. Conclusions Taken together, our findings provide further support for the role of HTT in metabolic control via hypothalamic neurocircuits. Understanding the specific central neurocircuits and their peripheral link underlying metabolic imbalance in HD may open up avenues for novel therapeutic interventions. Overexpression of hypothalamic huntingtin affects weight in Huntington's disease mice. Hypothalamic huntingtin expression results in gene expression changes in white fat and the hypothalamus. Hypothalamic huntingtin cannot prevent late-stage weight loss in R6/2 mice.
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