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Zhao K, So HC, Lin Z. scParser: sparse representation learning for scalable single-cell RNA sequencing data analysis. Genome Biol 2024; 25:223. [PMID: 39152499 PMCID: PMC11328435 DOI: 10.1186/s13059-024-03345-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 07/23/2024] [Indexed: 08/19/2024] Open
Abstract
The rapid rise in the availability and scale of scRNA-seq data needs scalable methods for integrative analysis. Though many methods for data integration have been developed, few focus on understanding the heterogeneous effects of biological conditions across different cell populations in integrative analysis. Our proposed scalable approach, scParser, models the heterogeneous effects from biological conditions, which unveils the key mechanisms by which gene expression contributes to phenotypes. Notably, the extended scParser pinpoints biological processes in cell subpopulations that contribute to disease pathogenesis. scParser achieves favorable performance in cell clustering compared to state-of-the-art methods and has a broad and diverse applicability.
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Affiliation(s)
- Kai Zhao
- Department of Statistics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Hon-Cheong So
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
- KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research of Common Diseases, Kunming Institute of Zoology and The Chinese University of Hong Kong, Hong Kong SAR, China.
- Department of Psychiatry, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
- Margaret K.L. Cheung Research Centre for Management of Parkinsonism, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
- Brain and Mind Institute, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
- Hong Kong Branch of the Chinese Academy of Sciences Center for Excellence in Animal Evolution and Genetics, The Chinese University of Hong Kong, Hong Kong SAR, China.
| | - Zhixiang Lin
- Department of Statistics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
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2
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Jiang M, Wang N, Zhang Y, Zhang J, Li Y, Yan X, Zhang H, Li C, Guan Y, Liang B, Zhang W, Wu Y. Insulin receptor isoform B is required for efficient proinsulin processing in pancreatic β cells. iScience 2024; 27:110017. [PMID: 39021804 PMCID: PMC11253548 DOI: 10.1016/j.isci.2024.110017] [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] [Received: 10/30/2023] [Revised: 03/27/2024] [Accepted: 05/14/2024] [Indexed: 07/20/2024] Open
Abstract
The insulin receptor (INSR, IR) has two isoforms, IRA and IRB, through alternative splicing. However, their distinct functions in vivo remain unclear. Here we generated β cell-specific IRB knockout (KO) mice (βIRBKO). The KO mice displayed worsened hyperinsulinemia and hyperproinsulinemia in diet-induced obesity due to impaired proinsulin processing in β cells. Mechanistically, loss of IRB suppresses eukaryotic translation initiation factor 4G1 (eIF4G1) by stabilizing the transcriptional receptor sterol-regulatory element binding protein 1 (SREBP1). Moreover, excessive autocrine proinsulin in βIRBKO mice enhances the activity of extracellular signal-regulated kinase (ERK) through the remaining IRA to further stabilize nuclear SREBP1, forming a feedback loop. Collectively, our study paves the way to dissecting the isoform-specific function of IR in vivo and highlights the important roles of IRB in insulin processing and protecting β cells from lipotoxicity in obesity.
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Affiliation(s)
- Mingchao Jiang
- Institute for Genome Engineered Animal Models of Human Diseases, National Center of Genetically Engineered Animal Models for International Research, Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian, Liaoning 116000, China
| | - Ning Wang
- Institute for Genome Engineered Animal Models of Human Diseases, National Center of Genetically Engineered Animal Models for International Research, Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian, Liaoning 116000, China
| | - Yuqin Zhang
- Institute for Genome Engineered Animal Models of Human Diseases, National Center of Genetically Engineered Animal Models for International Research, Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian, Liaoning 116000, China
| | - Jinjin Zhang
- Shandong Provincial Hospital, School of Laboratory Animal & Shandong Laboratory Animal Center, Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250021, China
| | - Youwei Li
- Institute for Genome Engineered Animal Models of Human Diseases, National Center of Genetically Engineered Animal Models for International Research, Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian, Liaoning 116000, China
- Haidu College, Qingdao Agricultural University, Laiyang, Shandong 265200, China
| | - Xiu Yan
- Institute for Genome Engineered Animal Models of Human Diseases, National Center of Genetically Engineered Animal Models for International Research, Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian, Liaoning 116000, China
| | - Honghao Zhang
- Institute for Genome Engineered Animal Models of Human Diseases, National Center of Genetically Engineered Animal Models for International Research, Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian, Liaoning 116000, China
| | - Chengbin Li
- Center for Life Sciences, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Youfei Guan
- Advanced Institute for Medical Sciences, Dalian Medical University, Dalian 116044, China
| | - Bin Liang
- Center for Life Sciences, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Weiping Zhang
- Department of Pathophysiology, Naval Medical University, Shanghai 200433, China
| | - Yingjie Wu
- Institute for Genome Engineered Animal Models of Human Diseases, National Center of Genetically Engineered Animal Models for International Research, Liaoning Provence Key Lab of Genome Engineered Animal Models, Dalian Medical University, Dalian, Liaoning 116000, China
- Shandong Provincial Hospital, School of Laboratory Animal & Shandong Laboratory Animal Center, Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, Shandong 250021, China
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Almansoori S, Alsters SI, Yiorkas AM, Nor Hashim NA, Walters RG, Chahal HS, Purkayastha S, Lessan N, Blakemore AIF. Oligogenic inheritance in severe adult obesity. Int J Obes (Lond) 2024; 48:815-820. [PMID: 38297031 PMCID: PMC11129943 DOI: 10.1038/s41366-024-01476-9] [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: 12/07/2022] [Revised: 11/13/2023] [Accepted: 01/17/2024] [Indexed: 02/02/2024]
Abstract
BACKGROUND/OBJECTIVE The genetic architecture of extreme non-syndromic obesity in adults remains to be elucidated. A range of genes are known to cause monogenic obesity, but even when pathogenic mutations are present, there may be variable penetrance. METHODS Whole-exome sequencing (WES) was carried out on a 15-year-old male proband of Pakistani ancestry who had severe obesity. This was followed by family segregation analysis, using Sanger sequencing. We also undertook re-analysis of WES data from 91 unrelated adults with severe obesity (86% white European ancestry) from the Personalised Medicine for Morbid Obesity (PMMO) cohort, recruited from the UK National Health Service. RESULTS We identified an oligogenic mode of inheritance of obesity in the proband's family-this provided the impetus to reanalyze existing sequence data in a separate dataset. Analysis of PMMO participant data revealed two further patients who carried more than one rare, predicted-deleterious mutation in a known monogenic obesity gene. In all three cases, the genes involved had known autosomal dominant inheritance, with incomplete penetrance. CONCLUSION Oligogenic inheritance may explain some of the variable penetrance in Mendelian forms of obesity. We caution clinicians and researchers to avoid confining sequence analysis to individual genes and, in particular, not to stop looking when the first potentially-causative mutation is found.
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Affiliation(s)
- Sumaya Almansoori
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK.
- Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, London, UK.
- College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai Healthcare City, Dubai, United Arab Emirates.
- Genome Center, Department of Forensic Science and Criminology, Dubai Police GHQ, Dubai, United Arab Emirates.
| | - Suzanne I Alsters
- South West Thames Regional Genetics Service, St George's University Hospitals NHS Foundation Trust, London, UK
| | - Andrianos M Yiorkas
- Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, London, UK
| | - Nikman Adli Nor Hashim
- Institute of Biological Sciences, Faculty of Science, Universiti Malaya, Kuala Lumpur, 50603, Malaysia
- Centre for Drug Research in Systems Biology, Structural Bioinformatics and Human Digital Imaging (CRYSTAL), Universiti Malaya, Kuala Lumpur, 50603, Malaysia
| | - Robin G Walters
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
- MRC Population Health Research Unit, University of Oxford, Oxford, UK
| | - Harvinder S Chahal
- Imperial Weight Centre, Imperial College Healthcare NHS Trust, St Mary's Hospital, Praed Street, London, W2 1NY, UK
- Section of Investigative Medicine, Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Campus, Hammersmith Hospital, 6th Floor Commonwealth Building, Du Cane Road, London, W12 0NN, UK
| | | | - Nader Lessan
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
- Imperial College London Diabetes Centre Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Alexandra I F Blakemore
- Department of Metabolism, Digestion and Reproduction, Imperial College London, London, UK
- Department of Life Sciences, College of Health, Medicine and Life Sciences, Brunel University London, London, UK
- College of Medicine, Nursing, and Health Science, University of Galway, Galway, Republic of Ireland
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Mazuecos L, Artigas-Jerónimo S, Pintado C, Gómez O, Rubio B, Arribas C, Andrés A, Villar M, Gallardo N. Central leptin signaling deficiency induced by leptin receptor antagonist leads to hypothalamic proteomic remodeling. Life Sci 2024; 346:122649. [PMID: 38626868 DOI: 10.1016/j.lfs.2024.122649] [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: 11/29/2023] [Revised: 04/07/2024] [Accepted: 04/11/2024] [Indexed: 04/20/2024]
Abstract
AIMS Leptin irresponsiveness, which is often associated with obesity, can have significant impacts on the hypothalamic proteome of individuals, including those who are lean. While mounting evidence on leptin irresponsiveness has focused on obese individuals, understanding the early molecular and proteomic changes associated with deficient hypothalamic leptin signaling in lean individuals is essential for early intervention and prevention of metabolic disorders. Leptin receptor antagonists block the binding of leptin to its receptors, potentially reducing its effects and used in cases where excessive leptin activity might be harmful. MATERIALS AND METHODS In this work, we blocked the central actions of leptin in lean male adult Wistar rat by chronically administering intracerebroventricularly the superactive leptin receptor antagonist (SLA) (D23L/L39A/D40A/F41A) and investigated its impact on the hypothalamic proteome using label-free sequential window acquisition of all theoretical fragment ion spectra mass spectrometry (SWATH-MS) for quantitative proteomics. KEY FINDINGS Our results show an accumulation of proteins involved in mRNA processing, mRNA stability, and translation in the hypothalamus of SLA-treated rats. Conversely, hypothalamic leptin signaling deficiency reduces the representation of proteins implicated in energy metabolism, neural circuitry, and neurotransmitter release. SIGNIFICANCE The alterations in the adult rat hypothalamic proteome contribute to dysregulate appetite, metabolism, and energy balance, which are key factors in the development and progression of obesity and related metabolic disorders. Additionally, using bioinformatic analysis, we identified a series of transcription factors that are potentially involved in the upstream regulatory mechanisms responsible for the observed signature.
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Affiliation(s)
- Lorena Mazuecos
- Biochemistry Section, Faculty of Sciences and Chemical Technologies, University of Castilla-La Mancha, Avda. Camilo Jose Cela 10, 13071 Ciudad Real, Spain; DOE, Regional Center for Biomedical Research (CRIB), Castilla-La Mancha, Spain
| | - Sara Artigas-Jerónimo
- Biochemistry Section, Faculty of Sciences and Chemical Technologies, University of Castilla-La Mancha, Avda. Camilo Jose Cela 10, 13071 Ciudad Real, Spain; DOE, Regional Center for Biomedical Research (CRIB), Castilla-La Mancha, Spain
| | - Cristina Pintado
- Biochemistry Section, Faculty of Environmental Sciences and Biochemistry, University of Castilla-La Mancha, Avda. Carlos III s/n, 45071 Toledo, Spain; DOE, Regional Center for Biomedical Research (CRIB), Castilla-La Mancha, Spain
| | - Oscar Gómez
- Biochemistry Section, Faculty of Environmental Sciences and Biochemistry, University of Castilla-La Mancha, Avda. Carlos III s/n, 45071 Toledo, Spain; DOE, Regional Center for Biomedical Research (CRIB), Castilla-La Mancha, Spain
| | - Blanca Rubio
- Biochemistry Section, Faculty of Sciences and Chemical Technologies, University of Castilla-La Mancha, Avda. Camilo Jose Cela 10, 13071 Ciudad Real, Spain; DOE, Regional Center for Biomedical Research (CRIB), Castilla-La Mancha, Spain
| | - Carmen Arribas
- Biochemistry Section, Faculty of Environmental Sciences and Biochemistry, University of Castilla-La Mancha, Avda. Carlos III s/n, 45071 Toledo, Spain; DOE, Regional Center for Biomedical Research (CRIB), Castilla-La Mancha, Spain
| | - Antonio Andrés
- Biochemistry Section, Faculty of Sciences and Chemical Technologies, University of Castilla-La Mancha, Avda. Camilo Jose Cela 10, 13071 Ciudad Real, Spain; DOE, Regional Center for Biomedical Research (CRIB), Castilla-La Mancha, Spain
| | - Margarita Villar
- Biochemistry Section, Faculty of Sciences and Chemical Technologies, University of Castilla-La Mancha, Avda. Camilo Jose Cela 10, 13071 Ciudad Real, Spain; SaBio, Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain.
| | - Nilda Gallardo
- Biochemistry Section, Faculty of Sciences and Chemical Technologies, University of Castilla-La Mancha, Avda. Camilo Jose Cela 10, 13071 Ciudad Real, Spain; DOE, Regional Center for Biomedical Research (CRIB), Castilla-La Mancha, Spain.
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Amato E, Taroc EZM, Forni PE. Illuminating the terminal nerve: Uncovering the link between GnRH-1 neuron and olfactory development. J Comp Neurol 2024; 532:e25599. [PMID: 38488687 PMCID: PMC10958589 DOI: 10.1002/cne.25599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/11/2024] [Accepted: 02/19/2024] [Indexed: 03/18/2024]
Abstract
During embryonic development, the olfactory placode (OP) generates migratory neurons, including olfactory pioneer neurons, cells of the terminal nerve (TN), gonadotropin-releasing hormone-1 (GnRH-1) neurons, and other uncharacterized neurons. Pioneer neurons from the OP induce olfactory bulb (OB) morphogenesis. In mice, GnRH-1 neurons appear in the olfactory system around mid-gestation and migrate via the TN axons to different brain regions. The GnRH-1 neurons are crucial in controlling the hypothalamic-pituitary-gonadal axis. Kallmann syndrome is characterized by impaired olfactory system development, defective OBs, secretion of GnRH-1, and infertility. The precise mechanistic link between the olfactory system and GnRH-1 development remains unclear. Studies in humans and mice highlight the importance of the prokineticin-2/prokineticin-receptor-2 (Prokr2) signaling pathway in OB morphogenesis and GnRH-1 neuronal migration. Prokr2 loss-of-function mutations can cause Kallmann syndrome (KS), and hence the Prokr2 signaling pathway represents a unique model to decipher the olfactory/GnRH-1 connection. We discovered that Prokr2 is expressed in the TN neurons during the critical period of GnRH-1 neuron formation, migration, and induction of OB morphogenesis. Single-cell RNA sequencing identified that the TN is formed by neurons distinct from the olfactory neurons. The TN neurons express multiple genes associated with KS. Our study suggests that the aberrant development of pioneer/TN neurons might cause the KS spectrum.
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Affiliation(s)
- Enrico Amato
- Department of Biological Sciences, The Center for Neuroscience Research, The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Ed Zandro M. Taroc
- Department of Biological Sciences, The Center for Neuroscience Research, The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Paolo E. Forni
- Department of Biological Sciences, The Center for Neuroscience Research, The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
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Kalinderi K, Goula V, Sapountzi E, Tsinopoulou VR, Fidani L. Syndromic and Monogenic Obesity: New Opportunities Due to Genetic-Based Pharmacological Treatment. CHILDREN (BASEL, SWITZERLAND) 2024; 11:153. [PMID: 38397265 PMCID: PMC10886848 DOI: 10.3390/children11020153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/21/2024] [Accepted: 01/23/2024] [Indexed: 02/25/2024]
Abstract
Obesity is a significant health problem with a continuously increasing prevalence among children and adolescents that has become a modern pandemic during the last decades. Nowadays, the genetic contribution to obesity is well-established. For this narrative review article, we searched PubMed and Scopus databases for peer-reviewed research, review articles, and meta-analyses regarding the genetics of obesity and current pharmacological treatment, published in the English language with no time restrictions. We also screened the references of the selected articles for possible additional articles in order to include most of the key recent evidence. Our research was conducted between December 2022 and December 2023. We used the terms "obesity", "genetics", "monogenic", "syndromic", "drugs", "autosomal dominant", "autosomal recessive", "leptin-melanocortin pathway", and "children" in different combinations. Recognizing the genetic background in obesity can enhance the effectiveness of treatment. During the last years, intense research in the field of obesity treatment has increased the number of available drugs. This review analyzes the main categories of syndromic and monogenic obesity discussing current data on genetic-based pharmacological treatment of genetic obesity and highlighting the necessity that cases of genetic obesity should follow specific, pharmacological treatment based on their genetic background.
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Affiliation(s)
- Kallirhoe Kalinderi
- Laboratory of Medical Biology-Genetics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Vasiliki Goula
- School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
| | - Evdoxia Sapountzi
- Second Department of Pediatrics, School of Medicine, Faculty of Health Sciences, AHEPA University Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece; (E.S.); (V.R.T.)
| | - Vasiliki Rengina Tsinopoulou
- Second Department of Pediatrics, School of Medicine, Faculty of Health Sciences, AHEPA University Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece; (E.S.); (V.R.T.)
| | - Liana Fidani
- Laboratory of Medical Biology-Genetics, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece;
- Second Department of Pediatrics, School of Medicine, Faculty of Health Sciences, AHEPA University Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece; (E.S.); (V.R.T.)
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7
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Han JC, Rasmussen MC, Forte AR, Schrage SB, Zafar SK, Haqq AM. Management of Monogenic and Syndromic Obesity. Gastroenterol Clin North Am 2023; 52:733-750. [PMID: 37919024 DOI: 10.1016/j.gtc.2023.08.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2023]
Abstract
Similar to the general population, lifestyle interventions focused on nutrition and physical activity form the foundation for treating obesity caused by rare genetic disorders. Additional therapies, including metreleptin and setmelanotide, that target defects within the leptin signaling pathway can effectively synergize with lifestyle efforts to treat monogenic disorders of leptin, leptin receptor, proopiomelanocortin (POMC), and proprotein convertase subtilisin/kexin type 1 (PCSK1) and syndromic conditions, such as the ciliopathies Bardet-Biedl and Alström syndromes, whose pathophysiological mechanisms also converge on the leptin pathway. Investigational treatments for Prader-Willi syndrome target specific defects caused by reduced expression of paternally derived genes within the chromosome 15q region.
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Affiliation(s)
- Joan C Han
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Diabetes, Obesity, and Metabolism Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; The Mindich Child Health and Development Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Marcus C Rasmussen
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Alison R Forte
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Stephanie B Schrage
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Sarah K Zafar
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Andrea M Haqq
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada; Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada
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Mainieri F, La Bella S, Rinaldi M, Chiarelli F. Rare genetic forms of obesity in childhood and adolescence, a comprehensive review of their molecular mechanisms and diagnostic approach. Eur J Pediatr 2023; 182:4781-4793. [PMID: 37607976 DOI: 10.1007/s00431-023-05159-x] [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: 06/12/2023] [Revised: 08/09/2023] [Accepted: 08/10/2023] [Indexed: 08/24/2023]
Abstract
Obesity represents a major health problem in the pediatric population with an increasing prevalence worldwide, associated with cardiovascular and metabolic disorders, and due to both genetic and environmental factors. Rare forms of obesity are mostly monogenic, and less frequently due to polygenic influence. Polygenic form of obesity is usually the common obesity with single gene variations exerting smaller impact on weight and is commonly non-syndromic.Non-syndromic monogenic obesity is associated with variants in single genes typically related to the hypothalamic leptin-melanocortin signalling pathway, which plays a key role in hunger and satiety regulation, thus body weight control. Patients with these genetic defects usually present with hyperphagia and early-onset severe obesity. Significant progress in genetic diagnostic testing has recently made for early identification of patients with genetic obesity, which guarantees prompt intervention in terms of therapeutic management of the disease. What is Known: • Obesity represents a major health problem among children and adolescents, with an increasing prevalence worldwide, associated with cardiovascular disease and metabolic abnormalities, and it can be due to both genetic and environmental factors. • Non-syndromic monogenic obesity is linked to modifications in single genes usually involved in the hypothalamic leptin-melanocortin signalling pathway, which plays a key role in hunger and satiety regulation. What is New: • The increasing understanding of rare forms of monogenic obesity has provided significant insights into the genetic causes of pediatric obesity, and our current knowledge of the various genes associated with childhood obesity is rapidly expanding. • A useful diagnostic algorithm for early identification of genetic obesity has been proposed, which can ensure a prompt intervention in terms of therapeutic management of the disease and an early prevention of the development of associated metabolic conditions.
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Affiliation(s)
| | | | - Marta Rinaldi
- Paediatric Department, Stoke Mandeville Hospital, Thames Valley Deanery, Oxford, UK
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Abstract
Obesity is a common complex trait that elevates the risk for various diseases, including type 2 diabetes and cardiovascular disease. A combination of environmental and genetic factors influences the pathogenesis of obesity. Advances in genomic technologies have driven the identification of multiple genetic loci associated with this disease, ranging from studying severe onset cases to investigating common multifactorial polygenic forms. Additionally, findings from epigenetic analyses of modifications to the genome that do not involve changes to the underlying DNA sequence have emerged as key signatures in the development of obesity. Such modifications can mediate the effects of environmental factors, including diet and lifestyle, on gene expression and clinical presentation. This review outlines what is known about the genetic and epigenetic contributors to obesity susceptibility, along with the albeit limited therapeutic options currently available. Furthermore, we delineate the potential mechanisms of actions through which epigenetic changes can mediate environmental influences and the related opportunities they present for future interventions in the management of obesity.
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Affiliation(s)
- Khanh Trang
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
| | - Struan F.A. Grant
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Division of Diabetes and Endocrinology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Department of Pediatrics, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 USA
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104 USA
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10
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Amato E, Taroc EZM, Forni PE. Illuminating the Terminal Nerve: Uncovering the Link between GnRH-1 and Olfactory Development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.31.555770. [PMID: 37693459 PMCID: PMC10491181 DOI: 10.1101/2023.08.31.555770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
During embryonic development, the olfactory placode (OP) generates migratory neurons, including olfactory pioneer neurons, cells of the terminal nerve (TN), Gonadotropin-releasing hormone-1 (GnRH-1) neurons, and other uncharacterized neurons. Pioneer neurons from the olfactory placode induce olfactory bulb morphogenesis. In mice, GnRH-1 neurons appear in the olfactory system around mid-gestation and migrate via the terminal nerve axons to different brain regions. The GnRH-1 neurons are crucial in controlling the hypothalamic-pituitary-gonadal (HPG) axis. Kallmann syndrome is characterized by impaired olfactory system development, defective olfactory bulbs, defective secretion of GnRH-1, and infertility. The precise mechanistic link between the olfactory system and GnRH-1 development remains unclear. Studies in humans and mice highlight the importance of the Prokineticin-2/Prokineticin-Receptor-2 (Prokr2) signaling pathway in olfactory bulb morphogenesis and GnRH-1 neuronal migration. Prokr2 loss-of-function mutations can cause Kallmann syndrome, and hence the Prokr2 signaling pathway represents a unique model to decipher the olfactory/GnRH-1 connection. We discovered that Prokr2 is expressed in the TN neurons during the critical period of GnRH-1 neuron formation, migration, and induction of olfactory bulb morphogenesis. Single-cell RNA sequencing identified that the TN is formed by neurons that are distinct from the olfactory neurons. The TN neurons express multiple genes associated with KS. Our study suggests that the aberrant development of pioneer/TN neurons might cause the KS spectrum. Key Points 1) Pioneer or terminal nerve neurons play a crucial role in initiating the development of the olfactory bulbs. We found that the Prokineticin Receptor-2 gene, associated with Kallmann syndrome, is expressed by the olfactory pioneer/terminal nerve neurons.2) We genetically traced, isolated, and conducted Single-cell RNA sequencing on terminal nerve neurons of rodents. This analysis revealed a significant enrichment of gene expression related to Kallmann syndrome.3) Our study indicates that the investigation of Pioneer/terminal nerve neurons should be a pivotal focal point for comprehending developmental defects affecting olfactory and GnRH-1 systems.
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11
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Chen YC, Taylor AJ, Fulcher JM, Swensen AC, Dai XQ, Komba M, Wrightson KL, Fok K, Patterson AE, Klein Geltink RI, MacDonald PE, Qian WJ, Verchere CB. Deletion of Carboxypeptidase E in β-Cells Disrupts Proinsulin Processing but Does Not Lead to Spontaneous Development of Diabetes in Mice. Diabetes 2023; 72:1277-1288. [PMID: 37364047 PMCID: PMC10450824 DOI: 10.2337/db22-0945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 06/22/2023] [Indexed: 06/28/2023]
Abstract
Carboxypeptidase E (CPE) facilitates the conversion of prohormones into mature hormones and is highly expressed in multiple neuroendocrine tissues. Carriers of CPE mutations have elevated plasma proinsulin and develop severe obesity and hyperglycemia. We aimed to determine whether loss of Cpe in pancreatic β-cells disrupts proinsulin processing and accelerates development of diabetes and obesity in mice. Pancreatic β-cell-specific Cpe knockout mice (βCpeKO; Cpefl/fl x Ins1Cre/+) lack mature insulin granules and have elevated proinsulin in plasma; however, glucose-and KCl-stimulated insulin secretion in βCpeKO islets remained intact. High-fat diet-fed βCpeKO mice showed weight gain and glucose tolerance comparable with those of Wt littermates. Notably, β-cell area was increased in chow-fed βCpeKO mice and β-cell replication was elevated in βCpeKO islets. Transcriptomic analysis of βCpeKO β-cells revealed elevated glycolysis and Hif1α-target gene expression. On high glucose challenge, β-cells from βCpeKO mice showed reduced mitochondrial membrane potential, increased reactive oxygen species, reduced MafA, and elevated Aldh1a3 transcript levels. Following multiple low-dose streptozotocin injections, βCpeKO mice had accelerated development of hyperglycemia with reduced β-cell insulin and Glut2 expression. These findings suggest that Cpe and proper proinsulin processing are critical in maintaining β-cell function during the development of hyperglycemia. ARTICLE HIGHLIGHTS Carboxypeptidase E (Cpe) is an enzyme that removes the carboxy-terminal arginine and lysine residues from peptide precursors. Mutations in CPE lead to obesity and type 2 diabetes in humans, and whole-body Cpe knockout or mutant mice are obese and hyperglycemic and fail to convert proinsulin to insulin. We show that β-cell-specific Cpe deletion in mice (βCpeKO) does not lead to the development of obesity or hyperglycemia, even after prolonged high-fat diet treatment. However, β-cell proliferation rate and β-cell area are increased, and the development of hyperglycemia induced by multiple low-dose streptozotocin injections is accelerated in βCpeKO mice.
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Affiliation(s)
- Yi-Chun Chen
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Austin J. Taylor
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - James M. Fulcher
- Integrative Omics, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA
| | - Adam C. Swensen
- Integrative Omics, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA
| | - Xiao-Qing Dai
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
| | - Mitsuhiro Komba
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
| | | | - Kenny Fok
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Annette E. Patterson
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ramon I. Klein Geltink
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Wei-Jun Qian
- Integrative Omics, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA
| | - C. Bruce Verchere
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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12
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Alur V, Raju V, Vastrad B, Vastrad C, Kavatagimath S, Kotturshetti S. Bioinformatics Analysis of Next Generation Sequencing Data Identifies Molecular Biomarkers Associated With Type 2 Diabetes Mellitus. Clin Med Insights Endocrinol Diabetes 2023; 16:11795514231155635. [PMID: 36844983 PMCID: PMC9944228 DOI: 10.1177/11795514231155635] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 01/19/2023] [Indexed: 02/23/2023] Open
Abstract
Background Type 2 diabetes mellitus (T2DM) is the most common metabolic disorder. The aim of the present investigation was to identify gene signature specific to T2DM. Methods The next generation sequencing (NGS) dataset GSE81608 was retrieved from the gene expression omnibus (GEO) database and analyzed to identify the differentially expressed genes (DEGs) between T2DM and normal controls. Then, Gene Ontology (GO) and pathway enrichment analysis, protein-protein interaction (PPI) network, modules, miRNA (micro RNA)-hub gene regulatory network construction and TF (transcription factor)-hub gene regulatory network construction, and topological analysis were performed. Receiver operating characteristic curve (ROC) analysis was also performed to verify the prognostic value of hub genes. Results A total of 927 DEGs (461 were up regulated and 466 down regulated genes) were identified in T2DM. GO and REACTOME results showed that DEGs mainly enriched in protein metabolic process, establishment of localization, metabolism of proteins, and metabolism. The top centrality hub genes APP, MYH9, TCTN2, USP7, SYNPO, GRB2, HSP90AB1, UBC, HSPA5, and SQSTM1 were screened out as the critical genes. ROC analysis provides prognostic value of hub genes. Conclusion The potential crucial genes, especially APP, MYH9, TCTN2, USP7, SYNPO, GRB2, HSP90AB1, UBC, HSPA5, and SQSTM1, might be linked with risk of T2DM. Our study provided novel insights of T2DM into genetics, molecular pathogenesis, and novel therapeutic targets.
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Affiliation(s)
- Varun Alur
- Department of Endocrinology, J.J.M
Medical College, Davanagere, Karnataka, India
| | - Varshita Raju
- Department of Obstetrics and
Gynecology, J.J.M Medical College, Davanagere, Karnataka, India
| | - Basavaraj Vastrad
- Department of Pharmaceutical Chemistry,
K.L.E. College of Pharmacy, Gadag, Karnataka, India
| | | | - Satish Kavatagimath
- Department of Pharmacognosy, K.L.E.
College of Pharmacy, Belagavi, Karnataka, India
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13
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Hinney A, Körner A, Fischer-Posovszky P. The promise of new anti-obesity therapies arising from knowledge of genetic obesity traits. Nat Rev Endocrinol 2022; 18:623-637. [PMID: 35902734 PMCID: PMC9330928 DOI: 10.1038/s41574-022-00716-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/17/2022] [Indexed: 02/07/2023]
Abstract
Obesity is a multifactorial and complex disease that often manifests in early childhood with a lifelong burden. Polygenic and monogenic obesity are driven by the interaction between genetic predisposition and environmental factors. Polygenic variants are frequent and confer small effect sizes. Rare monogenic obesity syndromes are caused by defined pathogenic variants in single genes with large effect sizes. Most of these genes are involved in the central nervous regulation of body weight; for example, genes of the leptin-melanocortin pathway. Clinically, patients with monogenic obesity present with impaired satiety, hyperphagia and pronounced food-seeking behaviour in early childhood, which leads to severe early-onset obesity. With the advent of novel pharmacological treatment options emerging for monogenic obesity syndromes that target the central melanocortin pathway, genetic testing is recommended for patients with rapid weight gain in infancy and additional clinical suggestive features. Likewise, patients with obesity associated with hypothalamic damage or other forms of syndromic obesity involving energy regulatory circuits could benefit from these novel pharmacological treatment options. Early identification of patients affected by syndromic obesity will lead to appropriate treatment, thereby preventing the development of obesity sequelae, avoiding failure of conservative treatment approaches and alleviating stigmatization of patients and their families.
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Affiliation(s)
- Anke Hinney
- Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy and University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
- Center for Translational Neuro- and Behavioral Sciences, University Hospital Essen, University of Duisburg-Essen, Essen, Germany.
| | - Antje Körner
- Leipzig University, Medical Faculty, Hospital for Children and Adolescents, Centre of Paediatric Research (CPL), Leipzig, Germany
- LIFE Child, Leipzig Research Centre for Civilization Diseases, Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
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14
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Rodríguez-López R, Gimeno-Ferrer F, do Santos DA, Ferrer-Bolufer I, Luján CG, Alcalá OZ, García-Banacloy A, Cogollos VB, Juan CS. Reviewed and updated Algorithm for Genetic Characterization of Syndromic Obesity Phenotypes. Curr Genomics 2022; 23:147-162. [PMID: 36777005 PMCID: PMC9878830 DOI: 10.2174/1389202923666220426093436] [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] [Received: 10/26/2021] [Revised: 11/30/2021] [Accepted: 02/01/2022] [Indexed: 11/22/2022] Open
Abstract
Background: Individuals with a phenotype of early-onset severe obesity associated with intellectual disability can have molecular diagnoses ranging from monogenic to complex genetic traits. Severe overweight is the major sign of a syndromic physical appearance and predicting the influence of a single gene and/or polygenic risk profile is extremely complicated among the majority of the cases. At present, considering rare monogenic bases as the principal etiology for the majority of obesity cases associated with intellectual disability is scientifically poor. The diversity of the molecular bases responsible for the two entities makes the appliance of the current routinely powerful genomics diagnostic tools essential. Objective: Clinical investigation of these difficult-to-diagnose patients requires pediatricians and neurologists to use optimized descriptions of signs and symptoms to improve genotype correlations. Methods: The use of modern integrated bioinformatics strategies which are conducted by experienced multidisciplinary clinical teams. Evaluation of the phenotype of the patient's family is also of importance. Results: The next step involves discarding the monogenic canonical obesity syndromes and considering infrequent unique molecular cases, and/or then polygenic bases. Adequate management of the application of the new technique and its diagnostic phases is essential for achieving good cost/efficiency balances. Conclusion: With the current clinical management, it is necessary to consider the potential coincidence of risk mutations for obesity in patients with genetic alterations that induce intellectual disability. In this review, we describe an updated algorithm for the molecular characterization and diagnosis of patients with a syndromic obesity phenotype.
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Affiliation(s)
- Raquel Rodríguez-López
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain;,Address correspondence to this author at the Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Avenida de las Tres Cruces no. 2 46014, Valencia, Spain; Tel: 0034 963 131 800 – 437317; Fax: 0034 963 131 979; E-mail:
| | - Fátima Gimeno-Ferrer
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - David Albuquerque do Santos
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - Irene Ferrer-Bolufer
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - Carola Guzmán Luján
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - Otilia Zomeño Alcalá
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | - Amor García-Banacloy
- Laboratory of Molecular Genetics, Clinical Analysis Service, General Hospital Consortium of Valencia, Valencia, Spain
| | | | - Carlos Sánchez Juan
- Endocrinology Service, General Hospital Consortium of Valencia, Valencia, Spain
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15
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AbouHashem N, Al-Shafai K, Al-Shafai M. The genetic elucidation of monogenic obesity in the Arab world: a systematic review. J Pediatr Endocrinol Metab 2022; 35:699-707. [PMID: 35437977 DOI: 10.1515/jpem-2021-0710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 03/21/2022] [Indexed: 11/15/2022]
Abstract
BACKGROUND Investigation of monogenic obesity (MO), a rare condition caused by a single gene variant(s), especially in consanguineous populations, is a powerful approach for obtaining novel insights into the genetic alterations involved. Here, we present a systematic review of the genetics of MO in the 22 Arab countries and apply protein modeling in silico to the missense variants reported. METHODS We searched four literature databases (PubMed, Web of Science, Science Direct and Scopus) from the time of their first creation until December 2020, utilizing broad search terms to capture all genetic studies related to MO in the Arab countries. Only articles published in peer-reviewed journals involving subjects from at least one of the 22 Arab countries and dealing with genetic variants related to MO were included. Protein modelling of the variants identified was performed using PyMOL. RESULTS The 30 cases with severe early-onset obesity identified in 13 studies carried 14 variants in five genes (LEP, LEPR, POMC, MC4R and CPE). All of these variants were pathogenic, homozygous and carried by members of consanguineous families. CONCLUSION Despite the elevated presence of consanguinity in the Arab countries, the genetic origins of MO remain largely unexplained and require additional studies, both of a genetic and functional character.
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Affiliation(s)
- Nadien AbouHashem
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
| | | | - Mashael Al-Shafai
- Department of Biomedical Sciences, College of Health Sciences, QU Health, Qatar University, Doha, Qatar
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16
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Xiao L, Loh YP. Neurotrophic Factor-α1/Carboxypeptidase E Functions in Neuroprotection and Alleviates Depression. Front Mol Neurosci 2022; 15:918852. [PMID: 35711734 PMCID: PMC9197069 DOI: 10.3389/fnmol.2022.918852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 04/29/2022] [Indexed: 11/13/2022] Open
Abstract
Depression is a major psychiatric disease affecting all ages and is often co-morbid with neurodegeneration in the elderly. Depression and neurodegeneration are associated with decreased neurotrophic factors. In this mini-review the functions and potential therapeutic use of a newly discovered trophic factor, Neurotrophic factor-α1 (NF-α1), also known as Carboxypeptidase E (CPE), in depression and neuroprotection are discussed. NF-α1/CPE expression is enriched in CA3 neurons of the hippocampus. Families carrying null and homozygous non-sense mutations of the NF-α1/CPE gene share common clinical features including childhood onset obesity, type 2 diabetes, impaired intellectual abilities and hypogonadotrophic hypogonadism. Studies in animal models such as CPE knockout (KO) mice and CPEfat/fat mutant mice exhibit similar phenotypes. Analysis of CPE-KO mouse brain revealed that hippocampal CA3 was completely degenerated after weaning stress, along with deficits in hippocampal long-term potentiation. Carbamazepine effectively blocked weaning stress-induced hippocampal CA3 degeneration, suggesting the stress induced epileptic-like neuronal firing led to the degeneration. Analysis of possible mechanisms underlying NF-α1/CPE -mediated neuroprotection revealed that it interacts with the serotonin receptor, 5-HTR1E, and via β arrestin activation, subsequently upregulates ERK1/2 signaling and pro-survival protein, BCL2, levels. Furthermore, the NF-α1/CPE promoter contains a peroxisome proliferator-activated receptor (PPARγ) binding site which can be activated by rosiglitazone, a PPARγ agonist, to up-regulate expression of NF-α1/CPE and neurogenesis, resulting in anti-depression in animal models. Rosiglitazone, an anti-diabetic drug administered to diabetic patients resulted in decline of depression. Thus, NF-α1/CPE is a potential therapeutic agent or drug target for treating depression and neurodegenerative disorders.
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17
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Fricker LD, Lemos Duarte M, Jeltyi A, Lueptow L, Fakira AK, Tashima AK, Hochgeschwender U, Wetsel WC, Devi LA. Mice heterozygous for a null mutation of Cpe show reduced expression of carboxypeptidase E mRNA and enzyme activity but normal physiology, behavior, and levels of neuropeptides. Brain Res 2022; 1789:147951. [PMID: 35618016 DOI: 10.1016/j.brainres.2022.147951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/18/2022] [Accepted: 05/19/2022] [Indexed: 11/02/2022]
Abstract
Carboxypeptidase E (CPE) is an essential enzyme that contributes to the biosynthesis of the vast majority of neuropeptides and peptide hormones. There are several reports claiming that small decreases in CPE activity cause physiological changes in animals and/or cultured cells, but these studies did not provide evidence that neuropeptide levels were affected by decreased CPE activity. In the present study, we tested if CPE is a rate-limiting enzyme in neuropeptide production using CpeNeo mice, which contain a neomycin cassette within the Cpe gene that eliminates enzyme expression. Homozygous CpeNeo/Neo mice show defects found in Cpefat/fat and/or Cpe global knockout (KO) mice, including greatly decreased levels of most neuropeptides, severely impaired fertility, depressive-like behavior, adult-onset obesity, and anxiety-like behavior. Removal of the neomycin cassette with Flp recombinase under a germline promoter restored expression of CPE activity and resulted in normal behavioral and physiological properties, including levels of neuropeptides. Mice heterozygous for the CpeNeo allele have greatly reduced levels of Cpe mRNA and CPE-like enzymatic activity. Despite the decreased levels of Cpe expression, heterozygous CpeNeo mice are behaviorally and physiologically identical to wild-type mice, with normal levels of most neuropeptides. These results indicate that CPE is not a rate-limiting enzyme in the production of most neuropeptides, casting doubt upon studies claiming small decreases in CPE activity contribute to obesity or other physiological effects.
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Affiliation(s)
- Lloyd D Fricker
- Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY 10461.
| | - Mariana Lemos Duarte
- Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, NY, NY, 10029.
| | - Andrei Jeltyi
- Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, NY, NY, 10029.
| | - Lindsay Lueptow
- Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, NY, NY, 10029.
| | - Amanda K Fakira
- Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, NY, NY, 10029.
| | - Alexandre K Tashima
- Department of Biochemistry, Escola Paulista de Medicina, Federal University of Sao Paulo, Sao Paulo, SP 04023-901, Brazil.
| | | | - William C Wetsel
- Departments of Psychiatry and Behavioral Sciences, Neurobiology, and Cell Biology, Duke University Medical Center, Durham, NC, 27710.
| | - Lakshmi A Devi
- Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, NY, NY, 10029.
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18
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Juriaans AF, Kerkhof GF, Hokken-Koelega ACS. The Spectrum of the Prader-Willi-like Pheno- and Genotype: A Review of the Literature. Endocr Rev 2022; 43:1-18. [PMID: 34460908 DOI: 10.1210/endrev/bnab026] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Indexed: 12/16/2022]
Abstract
Prader-Willi syndrome (PWS) is a rare genetic syndrome, caused by the loss of expression of the paternal chromosome 15q11-q13 region. Over the past years, many cases of patients with characteristics similar to PWS, but without a typical genetic aberration of the 15q11-q13 region, have been described. These patients are often labelled as Prader-Willi-like (PWL). PWL is an as-yet poorly defined syndrome, potentially affecting a significant number of children and adults. In the current clinical practice, patients labelled as PWL are mostly left without treatment options. Considering the similarities with PWS, children with PWL might benefit from the same care and treatment as children with PWS. This review gives more insight into the pheno- and genotype of PWL and includes 86 papers, containing 368 cases of patients with a PWL phenotype. We describe mutations and aberrations for consideration when suspicion of PWS remains after negative testing. The most common genetic diagnoses were Temple syndrome (formerly known as maternal uniparental disomy 14), Schaaf-Yang syndrome (truncating mutation in the MAGEL2 gene), 1p36 deletion, 2p deletion, 6q deletion, 6q duplication, 15q deletion, 15q duplication, 19p deletion, fragile X syndrome, and Xq duplication. We found that the most prevalent symptoms in the entire group were developmental delay/intellectual disability (76%), speech problems (64%), overweight/obesity (57%), hypotonia (56%), and psychobehavioral problems (53%). In addition, we propose a diagnostic approach to patients with a PWL phenotype for (pediatric) endocrinologists. PWL comprises a complex and diverse group of patients, which calls for multidisciplinary care with an individualized approach.
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Affiliation(s)
- Alicia F Juriaans
- National Reference Center for Prader-Willi Syndrome and Prader-Willi-like, The Netherlands.,Department of Pediatrics, Subdivision of Endocrinology, Erasmus Medical Center, The Netherlands.,Dutch Growth Research Foundation, Rotterdam, The Netherlands
| | - Gerthe F Kerkhof
- National Reference Center for Prader-Willi Syndrome and Prader-Willi-like, The Netherlands.,Department of Pediatrics, Subdivision of Endocrinology, Erasmus Medical Center, The Netherlands
| | - Anita C S Hokken-Koelega
- National Reference Center for Prader-Willi Syndrome and Prader-Willi-like, The Netherlands.,Department of Pediatrics, Subdivision of Endocrinology, Erasmus Medical Center, The Netherlands.,Dutch Growth Research Foundation, Rotterdam, The Netherlands
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19
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Sharma VK, Yang X, Kim SK, Mafi A, Saiz-Sanchez D, Villanueva-Anguita P, Xiao L, Inoue A, Goddard WA, Loh YP. Novel interaction between neurotrophic factor-α1/carboxypeptidase E and serotonin receptor, 5-HTR1E, protects human neurons against oxidative/neuroexcitotoxic stress via β-arrestin/ERK signaling. Cell Mol Life Sci 2021; 79:24. [PMID: 34966948 PMCID: PMC8732845 DOI: 10.1007/s00018-021-04021-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/14/2021] [Accepted: 11/01/2021] [Indexed: 12/18/2022]
Abstract
Protecting neurons from death during oxidative and neuroexcitotoxic stress is key for preventing cognitive dysfunction. We uncovered a novel neuroprotective mechanism involving interaction between neurotrophic factor-α1 (NF-α1/carboxypeptidase E, CPE) and human 5-HTR1E, a G protein-coupled serotonin receptor with no previously known neurological function. Co-immunoprecipitation and pull-down assays confirmed interaction between NFα1/CPE and 5-HTR1E and 125I NF-α1/CPE-binding studies demonstrated saturable, high-affinity binding to 5-HTR1E in stably transfected HEK293 cells (Kd = 13.82 nM). Treatment of 5-HTR1E stable cells with NF-α1/CPE increased pERK 1/2 and pCREB levels which prevented a decrease in pro-survival protein, BCL2, during H2O2-induced oxidative stress. Cell survival assay in β-arrestin Knockout HEK293 cells showed that the NF-α1/CPE-5-HTR1E-mediated protection against oxidative stress was β-arrestin-dependent. Molecular dynamics studies revealed that NF-α1/CPE interacts with 5-HTR1E via 3 salt bridges, stabilized by several hydrogen bonds, independent of the serotonin pocket. Furthermore, after phosphorylating the C-terminal tail and intracellular loop 3 (ICL3) of NF-α1/CPE-5-HTR1E, it recruited β-arrestin1 by forming numerous salt bridges and hydrogen bonds to ICL2 and ICL3, leading to activation of β-arrestin1. Immunofluorescence studies showed 5-HTR1E and NF-α1/CPE are highly expressed and co-localized on cell surface of human hippocampal neurons. Importantly, knock-down of 5-HTR1E in human primary neurons diminished the NF-α1/CPE-mediated protection of these neurons against oxidative stress and glutamate neurotoxicity-induced cell death. Thus, NF-α1/CPE uniquely interacts with serotonin receptor 5-HTR1E to activate the β-arrestin/ERK/CREB/BCL2 pathway to mediate stress-induced neuroprotection.
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Affiliation(s)
- Vinay Kumar Sharma
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 49, Convent Drive, Bldg 49, Rm 6A-10, Bethesda, MD, 20892, USA
| | - Xuyu Yang
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 49, Convent Drive, Bldg 49, Rm 6A-10, Bethesda, MD, 20892, USA
| | - Soo-Kyung Kim
- Materials and Process Simulation Center, California Institute of Technology, Pasedena, CA, 91125, USA
| | - Amirhossein Mafi
- Materials and Process Simulation Center, California Institute of Technology, Pasedena, CA, 91125, USA
| | - Daniel Saiz-Sanchez
- Neuroplasticity and Neurodegeneration Laboratory, Medical School, Regional Center for Biomedical Research, University of Castilla-La Mancha, 13071, Ciudad Real, Spain
| | - Patricia Villanueva-Anguita
- Neuroplasticity and Neurodegeneration Laboratory, Medical School, Regional Center for Biomedical Research, University of Castilla-La Mancha, 13071, Ciudad Real, Spain
| | - Lan Xiao
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 49, Convent Drive, Bldg 49, Rm 6A-10, Bethesda, MD, 20892, USA
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, 980-8578, Japan
| | - William A Goddard
- Materials and Process Simulation Center, California Institute of Technology, Pasedena, CA, 91125, USA.
| | - Y Peng Loh
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 49, Convent Drive, Bldg 49, Rm 6A-10, Bethesda, MD, 20892, USA.
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20
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Abstract
Idiopathic hypogonadotropic hypogonadism (IHH) is a group of rare developmental disorders characterized by low gonadotropin levels in the face of low sex steroid hormone concentrations. IHH is practically divided into two major groups according to the olfactory function: normal sense of smell (normosmia) nIHH, and reduced sense of smell (hyposmia/anosmia) Kallmann syndrome (KS). Although mutations in more than 50 genes have been associated with IHH so far, only half of those cases were explained by gene mutations. Various combinations of deleterious variants in different genes as causes of IHH have been increasingly recognized (Oligogenic etiology). In addition to the complexity of inheritance patterns, the spontaneous or sex steroid-induced clinical recovery from IHH, which is seen in approximately 10–20% of cases, blurs further the phenotype/genotype relationship in IHH, and poses challenging steps in new IHH gene discovery. Beyond helping for clinical diagnostics, identification of the genetic mutations in the pathophysiology of IHH is hoped to shed light on the central governance of the hypothalamo-pituitary-gonadal axis through life stages. This review aims to summarize the genetic etiology of IHH and discuss the clinical and physiological ramifications of the gene mutations.
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21
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Lindberg I, Fricker LD. Obesity, POMC, and POMC-processing Enzymes: Surprising Results From Animal Models. Endocrinology 2021; 162:6333651. [PMID: 34333593 PMCID: PMC8489426 DOI: 10.1210/endocr/bqab155] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Indexed: 11/19/2022]
Abstract
Peptides derived from proopiomelanocortin (POMC) are well-established neuropeptides and peptide hormones that perform multiple functions, including regulation of body weight. In humans and some animals, these peptides include α- and β-melanocyte-stimulating hormone (MSH). In certain rodent species, no β-MSH is produced from POMC because of a change in the cleavage site. Enzymes that convert POMC into MSH include prohormone convertases (PCs), carboxypeptidases (CPs), and peptidyl-α-amidating monooxygenase (PAM). Humans and mice with inactivating mutations in either PC1/3 or carboxypeptidase E (CPE) are obese, which was assumed to result from defective processing of POMC into MSH. However, recent studies have shown that selective loss of either PC1/3 or CPE in POMC-expressing cells does not cause obesity. These findings suggest that defects in POMC processing cannot alone account for the obesity observed in global PC1/3 or CPE mutants. We propose that obesity in animals lacking PC1/3 or CPE activity depends, at least in part, on deficient processing of peptides in non-POMC-expressing cells either in the brain and/or the periphery. Genetic background may also contribute to the manifestation of obesity.
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Affiliation(s)
- Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
- Correspondence: I. Lindberg, PhD, Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn St, Baltimore, MD 21201, USA.
| | - Lloyd D Fricker
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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22
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Bosch E, Hebebrand M, Popp B, Penger T, Behring B, Cox H, Towner S, Kraus C, Wilson WG, Khan S, Krumbiegel M, Ekici AB, Uebe S, Trollmann R, Woelfle J, Reis A, Vasileiou G. BDV Syndrome: An Emerging Syndrome With Profound Obesity and Neurodevelopmental Delay Resembling Prader-Willi Syndrome. J Clin Endocrinol Metab 2021; 106:3413-3427. [PMID: 34383079 DOI: 10.1210/clinem/dgab592] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Indexed: 12/17/2022]
Abstract
CONTEXT CPE encodes carboxypeptidase E, an enzyme that converts proneuropeptides and propeptide hormones to bioactive forms. It is widely expressed in the endocrine and central nervous system. To date, 4 individuals from 2 families with core clinical features including morbid obesity, neurodevelopmental delay, and hypogonadotropic hypogonadism, harboring biallelic loss-of-function (LoF) CPE variants, have been reported. OBJECTIVE We describe 4 affected individuals from 3 unrelated consanguineous families, 2 siblings of Syrian, 1 of Egyptian, and 1 of Pakistani descent, all harboring novel homozygous CPE LoF variants. METHODS After excluding Prader-Willi syndrome (PWS), exome sequencing was performed in both Syrian siblings. The variants identified in the other 2 individuals were reported as research variants in a large-scale exome study and in the ClinVar database. Computational modeling of all possible missense alterations allowed assessing CPE tolerance to missense variants. RESULTS All affected individuals were severely obese with neurodevelopmental delay and other endocrine anomalies. Three individuals from 2 families shared the same CPE homozygous truncating variant c.361C > T, p.(Arg121*), while the fourth carried the c.994del, p.(Ser333Alafs*22) variant. Comparison of clinical features with previously described cases and standardization according to the Human Phenotype Ontology terms indicated a recognizable clinical phenotype, which we termed Blakemore-Durmaz-Vasileiou (BDV) syndrome. Computational analysis indicated high conservation of CPE domains and intolerance to missense changes. CONCLUSION Biallelic truncating CPE variants are associated with BDV syndrome, a clinically recognizable monogenic recessive syndrome with childhood-onset obesity, neurodevelopmental delay, hypogonadotropic hypogonadism, and hypothyroidism. BDV syndrome resembles PWS. Our findings suggest missense variants may also be clinically relevant.
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Affiliation(s)
- Elisabeth Bosch
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Moritz Hebebrand
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Bernt Popp
- Institute of Human Genetics, University of Leipzig Hospitals and Clinics, 04103 Leipzig, Germany
| | - Theresa Penger
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Bettina Behring
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Helen Cox
- West Midlands Regional Clinical Genetics Unit, Birmingham Women's Hospital, Edgbaston, Birmingham B15 2TG, UK
| | - Shelley Towner
- Department of Pediatrics, Division of Genetics, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Cornelia Kraus
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - William G Wilson
- Department of Pediatrics, Division of Genetics, University of Virginia, Charlottesville, Virginia 22908, USA
| | - Shagufta Khan
- West Midlands Regional Clinical Genetics Unit, Birmingham Women's Hospital, Edgbaston, Birmingham B15 2TG, UK
| | - Mandy Krumbiegel
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Arif B Ekici
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Steffen Uebe
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Regina Trollmann
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Joachim Woelfle
- Department of Pediatrics and Adolescent Medicine, University Hospital Erlangen, 91054 Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
| | - Georgia Vasileiou
- Institute of Human Genetics, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054 Erlangen, Germany
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23
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Powell DR, Revelli JP, Doree DD, DaCosta CM, Desai U, Shadoan MK, Rodriguez L, Mullens M, Yang QM, Ding ZM, Kirkpatrick LL, Vogel P, Zambrowicz B, Sands AT, Platt KA, Hansen GM, Brommage R. High-Throughput Screening of Mouse Gene Knockouts Identifies Established and Novel High Body Fat Phenotypes. Diabetes Metab Syndr Obes 2021; 14:3753-3785. [PMID: 34483672 PMCID: PMC8409770 DOI: 10.2147/dmso.s322083] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 08/04/2021] [Indexed: 01/05/2023] Open
Abstract
PURPOSE Obesity is a major public health problem. Understanding which genes contribute to obesity may better predict individual risk and allow development of new therapies. Because obesity of a mouse gene knockout (KO) line predicts an association of the orthologous human gene with obesity, we reviewed data from the Lexicon Genome5000TM high throughput phenotypic screen (HTS) of mouse gene KOs to identify KO lines with high body fat. MATERIALS AND METHODS KO lines were generated using homologous recombination or gene trapping technologies. HTS body composition analyses were performed on adult wild-type and homozygous KO littermate mice from 3758 druggable mouse genes having a human ortholog. Body composition was measured by either DXA or QMR on chow-fed cohorts from all 3758 KO lines and was measured by QMR on independent high fat diet-fed cohorts from 2488 of these KO lines. Where possible, comparisons were made to HTS data from the International Mouse Phenotyping Consortium (IMPC). RESULTS Body fat data are presented for 75 KO lines. Of 46 KO lines where independent external published and/or IMPC KO lines are reported as obese, 43 had increased body fat. For the remaining 29 novel high body fat KO lines, Ksr2 and G2e3 are supported by data from additional independent KO cohorts, 6 (Asnsd1, Srpk2, Dpp8, Cxxc4, Tenm3 and Kiss1) are supported by data from additional internal cohorts, and the remaining 21 including Tle4, Ak5, Ntm, Tusc3, Ankk1, Mfap3l, Prok2 and Prokr2 were studied with HTS cohorts only. CONCLUSION These data support the finding of high body fat in 43 independent external published and/or IMPC KO lines. A novel obese phenotype was identified in 29 additional KO lines, with 27 still lacking the external confirmation now provided for Ksr2 and G2e3 KO mice. Undoubtedly, many mammalian obesity genes remain to be identified and characterized.
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Affiliation(s)
- David R Powell
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Jean-Pierre Revelli
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Deon D Doree
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Christopher M DaCosta
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Urvi Desai
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Melanie K Shadoan
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Lawrence Rodriguez
- Department of Information Technology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Michael Mullens
- Department of Information Technology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Qi M Yang
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Zhi-Ming Ding
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Laura L Kirkpatrick
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Peter Vogel
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
| | - Brian Zambrowicz
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
- Department of Information Technology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Arthur T Sands
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
- Department of Information Technology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Kenneth A Platt
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Gwenn M Hansen
- Department of Molecular Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, Tx, USA
| | - Robert Brommage
- Department of Pharmaceutical Biology, Lexicon Pharmaceuticals, Inc, The Woodlands, TX, USA
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24
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Ramzy A, Kieffer TJ. Altered islet prohormone processing: A cause or consequence of diabetes? Physiol Rev 2021; 102:155-208. [PMID: 34280055 DOI: 10.1152/physrev.00008.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Peptide hormones are first produced as larger precursor prohormones that require endoproteolytic cleavage to liberate the mature hormones. A structurally conserved but functionally distinct family of nine prohormone convertase enzymes (PCs) are responsible for cleavage of protein precursors of which PC1/3 and PC2 are known to be exclusive to neuroendocrine cells and responsible for prohormone cleavage. Differential expression of PCs within tissues define prohormone processing; whereas glucagon is the major product liberated from proglucagon via PC2 in pancreatic α-cells, proglucagon is preferentially processed by PC1/3 in intestinal L cells to produce glucagon-like peptides 1 and 2 (GLP-1, GLP-2). Beyond our understanding of processing of islet prohormones in healthy islets, there is convincing evidence that proinsulin, proIAPP, and proglucagon processing is altered during prediabetes and diabetes. There is predictive value of elevated circulating proinsulin or proinsulin : C-peptide ratio for progression to type 2 diabetes and elevated proinsulin or proinsulin : C-peptide is predictive for development of type 1 diabetes in at risk groups. After onset of diabetes, patients have elevated circulating proinsulin and proIAPP and proinsulin may be an autoantigen in type 1 diabetes. Further, preclinical studies reveal that α-cells have altered proglucagon processing during diabetes leading to increased GLP-1 production. We conclude that despite strong associative data, current evidence is inconclusive on the potential causal role of impaired prohormone processing in diabetes, and suggest that future work should focus on resolving the question of whether altered prohormone processing is a causal driver or merely a consequence of diabetes pathology.
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Affiliation(s)
- Adam Ramzy
- Laboratory of Molecular and Cellular Medicine, Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Timothy J Kieffer
- Laboratory of Molecular and Cellular Medicine, Department of Cellular and Physiological Sciences, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.,Department of Surgery, University of British Columbia, Vancouver, BC, Canada.,School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
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25
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Sabiha B, Bhatti A, Roomi S, John P, Ali J. In silico analysis of non-synonymous missense SNPs (nsSNPs) in CPE, GNAS genes and experimental validation in type II diabetes mellitus through Next Generation Sequencing. Genomics 2021; 113:2426-2440. [PMID: 34029697 DOI: 10.1016/j.ygeno.2021.05.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 12/11/2020] [Accepted: 05/19/2021] [Indexed: 12/12/2022]
Abstract
Non-synonymous missense SNPs (nsSNPs) in CPE and GNAS genes were investigated computationally. In silico identified nsSNPs were experimentally validated in type II diabetes mellitus (T2DM) in Pakistani Pathan population using next generation sequencing (NGS). Sixty two high-risk nsSNPs in CPE and 44 in GNAS were identified. Only 12 in GNAS were clinically significant. Thirty six high-risk nsSNPs in CPE and 08 clinically significant nsSNPs in GNAS lies in the most conserved regions. I-mutant predicted that nsSNPs decrease the proteins stability and ModPred predicted 20 and 12 post-translational modification sites in CPE and GNAS proteins respectively. Ramachandran plot showed 88.7% residues are in the most favored region of protein models. By experimentation, none of the nsSNPs were found to be associated with T2DM. In conclusion, this study differentiates the deleterious nsSNPs from the neutral ones. Although nsSNPs are not associated with T2DM, they can be targeted in other CPE and GNAS genes related disorders.
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Affiliation(s)
- Bibi Sabiha
- Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12 Islamabad, Pakistan
| | - Attya Bhatti
- Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12 Islamabad, Pakistan.
| | - Sohaib Roomi
- Department of Biosciences, COMSATS University Islamabad, Islamabad, Pakistan
| | - Peter John
- Healthcare Biotechnology, Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), H-12 Islamabad, Pakistan
| | - Johar Ali
- Center for Genome Sciences, Rehman Medical College, Phase-V, Hayatabad, Peshawar, Khyber Pakhtunkhwa, Pakistan
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26
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Durmaz A, Aykut A, Atik T, Özen S, Ayyıldız Emecen D, Ata A, Işık E, Gökşen D, Çoğulu Ö, Özkınay F. A New Cause of Obesity Syndrome Associated with a Mutation in the Carboxypeptidase Gene Detected in Three Siblings with Obesity, Intellectual Disability and Hypogonadotropic Hypogonadism. J Clin Res Pediatr Endocrinol 2021; 13:52-60. [PMID: 32936766 PMCID: PMC7947731 DOI: 10.4274/jcrpe.galenos.2020.2020.0101] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVE Carboxypeptidase E (CPE) plays a critical role in the biosynthesis of peptide hormones and neuropeptides in the endocrine system and central nervous system. CPE knockout mice models exhibit disorders such as diabetes, hyperproinsulinaemia, low bone mineral density and neurodevelopmental disorders. Only one patient is described with morbid obesity, intellectual disability, abnormal glucose homeostasis and hypogonadotropic hypogonadism, which was associated with a homozygous frameshift deletion in CPE. METHODS Herein are described three siblings with obesity, intellectual disability and hypogonadotropic hypogonadism. Whole exome sequencing (WES) was performed in the index case. Candidate variants were prioritised and segregation of the variant, consistent with the phenotype of the index case, was assessed by Sanger sequencing in affected siblings and parents. RESULTS WES analysis revealed a homozygous nonsense c.405C>A (p.Y135*) mutation in CPE. Validation and segregation analysis confirmed the homozygous mutation in the index case and his affected siblings. The parents were phenotypically normal heterozygous mutation carriers. CONCLUSION This study provides additional evidence of the association between a homozygous nonsense mutation in CPE and a clinical phenotype consisting of obesity, intellectual disability and hypogonadotropic hypogonadism, which may be considered as a new monogenic obesity syndrome.
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Affiliation(s)
- Asude Durmaz
- Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey,* Address for Correspondence: Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey E-mail:
| | - Ayça Aykut
- Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey
| | - Tahir Atik
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
| | - Samim Özen
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Endocrinology, İzmir, Turkey
| | - Durdugül Ayyıldız Emecen
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
| | - Aysun Ata
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Endocrinology, İzmir, Turkey
| | - Esra Işık
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
| | - Damla Gökşen
- Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Endocrinology, İzmir, Turkey
| | - Özgür Çoğulu
- Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey,Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
| | - Ferda Özkınay
- Ege University Faculty of Medicine, Department of Medical Genetics, İzmir, Turkey,Ege University Faculty of Medicine, Department of Pediatrics, Subdivision of Pediatric Genetics, İzmir, Turkey
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Devarbhavi P, Telang L, Vastrad B, Tengli A, Vastrad C, Kotturshetti I. Identification of key pathways and genes in polycystic ovary syndrome via integrated bioinformatics analysis and prediction of small therapeutic molecules. Reprod Biol Endocrinol 2021; 19:31. [PMID: 33622336 PMCID: PMC7901211 DOI: 10.1186/s12958-021-00706-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/28/2021] [Indexed: 02/06/2023] Open
Abstract
To enhance understanding of polycystic ovary syndrome (PCOS) at the molecular level; this investigation intends to examine the genes and pathways associated with PCOS by using an integrated bioinformatics analysis. Based on the expression profiling by high throughput sequencing data GSE84958 derived from the Gene Expression Omnibus (GEO) database, the differentially expressed genes (DEGs) between PCOS samples and normal controls were identified. We performed a functional enrichment analysis. A protein-protein interaction (PPI) network, miRNA- target genes and TF - target gene networks, were constructed and visualized, with which the hub gene nodes were identified. Validation of hub genes was performed by using receiver operating characteristic (ROC) and RT-PCR. Small drug molecules were predicted by using molecular docking. A total of 739 DEGs were identified, of which 360 genes were up regulated and 379 genes were down regulated. GO enrichment analysis revealed that up regulated genes were mainly involved in peptide metabolic process, organelle envelope and RNA binding and the down regulated genes were significantly enriched in plasma membrane bounded cell projection organization, neuron projection and DNA-binding transcription factor activity, RNA polymerase II-specific. REACTOME pathway enrichment analysis revealed that the up regulated genes were mainly enriched in translation and respiratory electron transport and the down regulated genes were mainly enriched in generic transcription pathway and transmembrane transport of small molecules. The top 10 hub genes (SAA1, ADCY6, POLR2K, RPS15, RPS15A, CTNND1, ESR1, NEDD4L, KNTC1 and NGFR) were identified from PPI network, miRNA - target gene network and TF - target gene network. The modules analysis showed that genes in modules were mainly associated with the transport of respiratory electrons and signaling NGF, respectively. We find a series of crucial genes along with the pathways that were most closely related with PCOS initiation and advancement. Our investigations provide a more detailed molecular mechanism for the progression of PCOS, detail information on the potential biomarkers and therapeutic targets.
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Affiliation(s)
- Praveenkumar Devarbhavi
- Department of Endocrinology and Metabolism, Subbaiah Institute of Medical Sciences and Research Centre, Shimoga, Karnataka, 577201, India
| | - Lata Telang
- Department of Gynaecology and Obstetrics, Subbaiah Institute of Medical Sciences and Research Centre, Shimoga, Karnataka, 577201, India
| | - Basavaraj Vastrad
- Department of Biochemistry, Basaveshwar College of Pharmacy, Gadag, Karnataka, 582103, India
| | - Anandkumar Tengli
- Department of Pharmaceutical Chemistry, JSS College of Pharmacy, Mysuru and JSS Academy of Higher Education & Research, Mysuru, Karnataka, 570015, India
| | - Chanabasayya Vastrad
- Biostatistics and Bioinformatics, Chanabasava Nilaya, Bharthinagar, Dharwad, Karanataka, 580001, India.
| | - Iranna Kotturshetti
- Department of Ayurveda, Rajiv Gandhi Education Society's Ayurvedic Medical College, Ron, Karanataka, 562209, India
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28
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Abstract
Neural circuits in the hypothalamus play a key role in the regulation of human energy homeostasis. A critical circuit involves leptin-responsive neurons in the hypothalamic arcuate nucleus (the infundibular nucleus in humans) expressing the appetite-suppressing neuropeptide proopiomelanocortin (POMC) and the appetite-stimulating Agouti-related peptide. In the fed state, the POMC-derived melanocortin peptide α-melanocyte-stimulating hormone stimulates melanocortin-4 receptors (MC4Rs) expressed on second-order neurons in the paraventricular nucleus of the hypothalamus (PVN). Agonism of MC4R leads to reduced food intake and increased energy expenditure. Disruption of this hypothalamic circuit by inherited mutations in the genes encoding leptin, the leptin receptor, POMC, and MC4R can lead to severe obesity in humans. The characterization of these and closely related genetic obesity syndromes has informed our understanding of the neural pathways by which leptin regulates energy balance, neuroendocrine function, and the autonomic nervous system. A broader understanding of these neural and molecular mechanisms has paved the way for effective mechanism-based therapies for patients whose severe obesity is driven by disruption of these pathways.
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Affiliation(s)
- I Sadaf Farooqi
- Wellcome-MRC Institute of Metabolic Science, University of Cambridge, Cambridge, United Kingdom.
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29
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Chougule A, Kolli V, Baroi S, Ebraheim N, Czernik PJ, Loh YP, Lecka-Czernik B. Nonenzymatic and Trophic Activities of Carboxypeptidase E Regulate Bone Mass and Bioenergetics of Skeletal Stem Cells in Mice. JBMR Plus 2020; 4:e10392. [PMID: 32995694 PMCID: PMC7507073 DOI: 10.1002/jbm4.10392] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/24/2020] [Accepted: 06/30/2020] [Indexed: 12/20/2022] Open
Abstract
Bone and energy metabolism are integrated by common regulatory mechanisms. Carboxypeptidase E (CPE), also known as obesity susceptibility protein or neurotrophic factor‐α1, is recognized for its function in processing prohormones, including proinsulin and pro‐opiomelanocortin polypeptide. Independent of its enzymatic activity, CPE may also act as a secreted factor with divergent roles in neuroprotection and cancer growth; however, its role in the regulation of bone mass and skeletal cell differentiation is unknown. Male mice with global deficiency in CPE are characterized with profound visceral obesity, low bone mass in both appendicular and axial skeleton, and high volume of marrow fat. Interestingly, although metabolic deficit of CPE KO mice develops early in life, bone deficit develops in older age, suggesting that CPE bone‐specific activities differ from its enzymatic activities. Indeed, mutated CPE knockin (mCPE KI) mice ectopically expressing CPE‐E342Q, a mutated protein lacking enzymatic activity, develop the same obese phenotype and accumulate the same volume of marrow fat as CPE KO mice, but their bone mass is normal. In addition, differentiation of marrow hematopoietic cells toward tartrate‐resistant acid phosphatase‐positive multinucleated osteoclasts is highly increased in CPE KO mice, but normal in mCPE KI mice. Moreover, in murine skeletal stem cells, nonenzymatic trophic CPE has activated ERK signaling, increased cell proliferation and increased mitochondrial activity. Treatment of preosteoblastic cells with intact or mutated recombinant CPE led to a transient accumulation of small lipid droplets, increased oxidative phosphorylation, and increased cellular dependence on fatty acids as fuel for energy production. In human marrow aspirates, CPE expression increases up to 30‐fold in osteogenic conditions. These findings suggest that nonenzymatic and trophic activities of CPE regulate bone mass, whereas marrow adiposity is controlled by CPE enzymatic activity. Thus, CPE can be positioned as a factor regulating simultaneously bone and energy metabolism through a combination of shared and distinct mechanisms. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Amit Chougule
- Department of Orthopaedic Surgery University of Toledo, College of Medicine and Life Sciences Toledo OH USA.,Center for Diabetes and Endocrine Research University of Toledo, College of Medicine and Life Sciences Toledo OH USA
| | - Vipula Kolli
- Section on Cellular Neurobiology Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda MD USA
| | - Sudipta Baroi
- Department of Orthopaedic Surgery University of Toledo, College of Medicine and Life Sciences Toledo OH USA.,Center for Diabetes and Endocrine Research University of Toledo, College of Medicine and Life Sciences Toledo OH USA
| | - Nabil Ebraheim
- Department of Orthopaedic Surgery University of Toledo, College of Medicine and Life Sciences Toledo OH USA
| | - Piotr J Czernik
- Department of Physiology and Pharmacology University of Toledo, College of Medicine and Life Sciences Toledo OH USA
| | - Y Peng Loh
- Section on Cellular Neurobiology Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda MD USA
| | - Beata Lecka-Czernik
- Department of Orthopaedic Surgery University of Toledo, College of Medicine and Life Sciences Toledo OH USA.,Department of Physiology and Pharmacology University of Toledo, College of Medicine and Life Sciences Toledo OH USA.,Center for Diabetes and Endocrine Research University of Toledo, College of Medicine and Life Sciences Toledo OH USA
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Corrigan JK, Ramachandran D, He Y, Palmer CJ, Jurczak MJ, Chen R, Li B, Friedline RH, Kim JK, Ramsey JJ, Lantier L, McGuinness OP, Banks AS. A big-data approach to understanding metabolic rate and response to obesity in laboratory mice. eLife 2020; 9:e53560. [PMID: 32356724 PMCID: PMC7274785 DOI: 10.7554/elife.53560] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Accepted: 04/30/2020] [Indexed: 12/21/2022] Open
Abstract
Maintaining a healthy body weight requires an exquisite balance between energy intake and energy expenditure. To understand the genetic and environmental factors that contribute to the regulation of body weight, an important first step is to establish the normal range of metabolic values and primary sources contributing to variability. Energy metabolism is measured by powerful and sensitive indirect calorimetry devices. Analysis of nearly 10,000 wild-type mice from two large-scale experiments revealed that the largest variation in energy expenditure is due to body composition, ambient temperature, and institutional site of experimentation. We also analyze variation in 2329 knockout strains and establish a reference for the magnitude of metabolic changes. Based on these findings, we provide suggestions for how best to design and conduct energy balance experiments in rodents. These recommendations will move us closer to the goal of a centralized physiological repository to foster transparency, rigor and reproducibility in metabolic physiology experimentation.
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Affiliation(s)
- June K Corrigan
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical SchoolBostonUnited States
| | - Deepti Ramachandran
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical SchoolBostonUnited States
| | - Yuchen He
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical SchoolBostonUnited States
| | - Colin J Palmer
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical SchoolBostonUnited States
| | - Michael J Jurczak
- Division of Endocrinology, Yale University School of MedicineNew HavenUnited States
| | - Rui Chen
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of MedicineNashvilleUnited States
| | - Bingshan Li
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of MedicineNashvilleUnited States
| | - Randall H Friedline
- Program in Molecular Medicine, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Jason K Kim
- Program in Molecular Medicine, University of Massachusetts Medical SchoolWorcesterUnited States
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Massachusetts Medical SchoolWorcesterUnited States
| | - Jon J Ramsey
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, DavisDavisUnited States
| | - Louise Lantier
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of MedicineNashvilleUnited States
| | - Owen P McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of MedicineNashvilleUnited States
| | - Mouse Metabolic Phenotyping Center Energy Balance Working Group
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical SchoolBostonUnited States
- Division of Endocrinology, Yale University School of MedicineNew HavenUnited States
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of MedicineNashvilleUnited States
- Program in Molecular Medicine, University of Massachusetts Medical SchoolWorcesterUnited States
- Division of Endocrinology, Metabolism, and Diabetes, Department of Medicine, University of Massachusetts Medical SchoolWorcesterUnited States
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California, DavisDavisUnited States
| | - Alexander S Banks
- Division of Endocrinology, Diabetes and Metabolism, Beth Israel Deaconess Medical Center and Harvard Medical SchoolBostonUnited States
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Butz H, Nyírő G, Kurucz PA, Likó I, Patócs A. Molecular genetic diagnostics of hypogonadotropic hypogonadism: from panel design towards result interpretation in clinical practice. Hum Genet 2020; 140:113-134. [PMID: 32222824 PMCID: PMC7864839 DOI: 10.1007/s00439-020-02148-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 03/05/2020] [Indexed: 12/13/2022]
Abstract
Congenital hypogonadotropic hypogonadism (CHH) is a clinically and genetically heterogeneous congenital disease. Symptoms cover a wide spectrum from mild forms to complex phenotypes due to gonadotropin-releasing hormone (GnRH) deficiency. To date, more than 40 genes have been identified as pathogenic cause of CHH. These genes could be grouped into two major categories: genes controlling development and GnRH neuron migration and genes being responsible for neuroendocrine regulation and GnRH neuron function. High-throughput, next-generation sequencing (NGS) allows to analyze numerous gene sequences at the same time. Nowadays, whole exome or whole genome datasets could be investigated in clinical genetic diagnostics due to their favorable cost-benefit. The increasing genetic data generated by NGS reveal novel candidate genes and gene variants with unknown significance (VUSs). To provide clinically valuable genetic results, complex clinical and bioinformatics work are needed. The multifaceted genetics of CHH, the variable mode of inheritance, the incomplete penetrance, variable expressivity and oligogenic characteristics further complicate the interpretation of the genetic variants detected. The objective of this work, apart from reviewing the currently known genes associated with CHH, was to summarize the advantages and disadvantages of the NGS-based platforms and through the authors' own practice to guide through the whole workflow starting from gene panel design, performance analysis and result interpretation. Based on our results, a genetic diagnosis was clearly identified in 21% of cases tested (8/38).
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Affiliation(s)
- Henriett Butz
- Department of Laboratory Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary.,Hereditary Tumours Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.,Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary
| | - Gábor Nyírő
- Department of Laboratory Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary.,Molecular Medicine Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary.,2nd Department of Internal Medicine, Semmelweis University, Budapest, Hungary
| | - Petra Anna Kurucz
- Department of Laboratory Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - István Likó
- Hereditary Tumours Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Attila Patócs
- Department of Laboratory Medicine, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary. .,Hereditary Tumours Research Group, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary. .,Department of Molecular Genetics, National Institute of Oncology, Budapest, Hungary.
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32
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Mullin BH, Tickner J, Zhu K, Kenny J, Mullin S, Brown SJ, Dudbridge F, Pavlos NJ, Mocarski ES, Walsh JP, Xu J, Wilson SG. Characterisation of genetic regulatory effects for osteoporosis risk variants in human osteoclasts. Genome Biol 2020; 21:80. [PMID: 32216834 PMCID: PMC7098081 DOI: 10.1186/s13059-020-01997-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 03/11/2020] [Indexed: 12/15/2022] Open
Abstract
Background Osteoporosis is a complex disease with a strong genetic contribution. A recently published genome-wide association study (GWAS) for estimated bone mineral density (eBMD) identified 1103 independent genome-wide significant association signals. Most of these variants are non-coding, suggesting that regulatory effects may drive many of the associations. To identify genes with a role in osteoporosis, we integrate the eBMD GWAS association results with those from our previous osteoclast expression quantitative trait locus (eQTL) dataset. Results We identify sixty-nine significant cis-eQTL effects for eBMD GWAS variants after correction for multiple testing. We detect co-localisation of eBMD GWAS and osteoclast eQTL association signals for 21 of the 69 loci, implicating a number of genes including CCR5, ZBTB38, CPE, GNA12, RIPK3, IQGAP1 and FLCN. Summary-data-based Mendelian Randomisation analysis of the eBMD GWAS and osteoclast eQTL datasets identifies significant associations for 53 genes, with TULP4 presenting as a strong candidate for pleiotropic effects on eBMD and gene expression in osteoclasts. By performing analysis using the GARFIELD software, we demonstrate significant enrichment of osteoporosis risk variants among high-confidence osteoclast eQTL across multiple GWAS P value thresholds. Mice lacking one of the genes of interest, the apoptosis/necroptosis gene RIPK3, show disturbed bone micro-architecture and increased osteoclast number, highlighting a new biological pathway relevant to osteoporosis. Conclusion We utilise a unique osteoclast eQTL dataset to identify a number of potential effector genes for osteoporosis risk variants, which will help focus functional studies in this area.
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Affiliation(s)
- Benjamin H Mullin
- Department of Endocrinology & Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia. .,School of Biomedical Sciences, The University of Western Australia, Crawley, WA, 6009, Australia.
| | - Jennifer Tickner
- School of Biomedical Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Kun Zhu
- Department of Endocrinology & Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia.,School of Biomedical Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Jacob Kenny
- School of Biomedical Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Shelby Mullin
- Department of Endocrinology & Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia.,School of Biomedical Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Suzanne J Brown
- Department of Endocrinology & Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia
| | - Frank Dudbridge
- Department of Health Sciences, University of Leicester, Leicester, UK
| | - Nathan J Pavlos
- School of Biomedical Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Edward S Mocarski
- Department of Microbiology and Immunology, Emory Vaccine Center, School of Medicine, Emory University, Atlanta, GA, USA
| | - John P Walsh
- Department of Endocrinology & Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia.,Medical School, The University of Western Australia, Crawley, WA, Australia
| | - Jiake Xu
- School of Biomedical Sciences, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Scott G Wilson
- Department of Endocrinology & Diabetes, Sir Charles Gairdner Hospital, Nedlands, WA, Australia.,School of Biomedical Sciences, The University of Western Australia, Crawley, WA, 6009, Australia.,Department of Twin Research & Genetic Epidemiology, King's College London, London, UK
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Powell DR, Doree DD, DaCosta CM, Platt KA, Hansen GM, van Sligtenhorst I, Ding ZM, Revelli JP, Brommage R. Obesity of G2e3 Knockout Mice Suggests That Obesity-Associated Variants Near Human G2E3 Decrease G2E3 Activity. Diabetes Metab Syndr Obes 2020; 13:2641-2652. [PMID: 32801815 PMCID: PMC7394505 DOI: 10.2147/dmso.s259546] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/02/2020] [Indexed: 12/12/2022] Open
Abstract
PURPOSE In humans, single nucleotide polymorphisms (SNPs) near the adjacent protein kinase D1 (PRKD1) and G2/M-phase-specific E3 ubiquitin protein ligase (G2E3) genes on chromosome 14 are associated with obesity. To date, no published evidence links inactivation of either gene to changes in body fat. These two genes are also adjacent on mouse chromosome 12. Because obesity genes are highly conserved between humans and mice, we analyzed body fat in adult G2e3 and Prkd1 knockout (KO) mice to determine whether inactivating either gene leads to obesity in mice and, by inference, probably in humans. METHODS The G2e3 and Prkd1 KO lines were generated by gene trapping and by homologous recombination methodologies, respectively. Body fat was measured by DEXA in adult mice fed chow from weaning and by QMR in a separate cohort of mice fed high-fat diet (HFD) from weaning. Glucose homeostasis was evaluated with oral glucose tolerance tests (OGTTs) performed on adult mice fed HFD from weaning. RESULTS Body fat was increased in multiple cohorts of G2e3 KO mice relative to their wild-type (WT) littermates. When data from all G2e3 KO (n=32) and WT (n=31) mice were compared, KO mice showed increases of 11% in body weight (P<0.01), 65% in body fat (P<0.001), 48% in % body fat (P<0.001), and an insignificant 3% decrease in lean body mass. G2e3 KO mice were also glucose intolerant during an OGTT (P<0.05). In contrast, Prkd1 KO and WT mice had comparable body fat levels and glucose tolerance. CONCLUSION Significant obesity and glucose intolerance were observed in G2e3, but not Prkd1, KO mice. The conservation of obesity genes between mice and humans strongly suggests that the obesity-associated SNPs located near the human G2E3 and PRKD1 genes are linked to variants that decrease the amount of functional human G2E3.
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Affiliation(s)
- David R Powell
- Lexicon Pharmaceuticals Inc, The Woodlands, TX, 77381, USA
- Correspondence: David R Powell Lexicon Pharmaceuticals Inc., 8800 Technology Forest Place, The Woodlands, TX77381, USATel +1 281 863 3060Fax +1 281 863 8115 Email
| | - Deon D Doree
- Lexicon Pharmaceuticals Inc, The Woodlands, TX, 77381, USA
| | | | | | - Gwenn M Hansen
- Lexicon Pharmaceuticals Inc, The Woodlands, TX, 77381, USA
| | | | - Zhi-Ming Ding
- Lexicon Pharmaceuticals Inc, The Woodlands, TX, 77381, USA
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Loid P, Mustila T, Mäkitie RE, Viljakainen H, Kämpe A, Tossavainen P, Lipsanen-Nyman M, Pekkinen M, Mäkitie O. Rare Variants in Genes Linked to Appetite Control and Hypothalamic Development in Early-Onset Severe Obesity. Front Endocrinol (Lausanne) 2020; 11:81. [PMID: 32153512 PMCID: PMC7047210 DOI: 10.3389/fendo.2020.00081] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 02/07/2020] [Indexed: 12/11/2022] Open
Abstract
Context: The hypothalamic circuit has an essential role in the regulation of appetite and energy expenditure. Pathogenic variants in genes involved in the hypothalamic leptin-melanocortin pathway, including melanocortin-4-receptor (MC4R), have been associated with monogenic obesity. Objective: To determine the rate and spectrum of rare variants in genes involved in melanocortin pathway or hypothalamic development in patients with severe early-onset obesity (height-adjusted weight >60% before age 10 years). Methods: We used a custom-made targeted exome sequencing panel to assess peripheral blood DNA samples for rare (minor allele frequency <0.5%), pathogenic/likely pathogenic variants in 24 genes related to the hypothalamic circuit in 92 subjects (51% males, median age 13.7 years) with early-onset severe obesity (median body mass index (BMI) Z-score + 4.0). Results: We identified a novel frameshift deletion in MC4R (p.V103Afs5*) in two unrelated patients and a previously reported MC4R variant (p.T112M) in one patient. In addition, we identified rare heterozygous missense variants in ADCY3 (p.G1110R), MYT1L (p.R807Q), ISL1 (p.I347F), LRP2 (p.R2479I, and p.N3315S) and a hemizygous missense variant in GRPR (p.L87M) (each in one patient), possibly contributing to the obesity phenotype in these patients. Altogether 8 % (7/92) of the subjects had rare pathogenic/likely pathogenic variants in the studied genes. Conclusions: Rare genetic variants within the hypothalamic circuit are prevalent and contribute to the development of severe early-onset obesity. Targeted exome sequencing is useful in identifying affected subjects. Further studies are needed to evaluate the variants' clinical significance and to define optimal treatment.
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Affiliation(s)
- Petra Loid
- Children's Hospital, Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Genetics Research Program, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- *Correspondence: Petra Loid
| | - Taina Mustila
- Department of Pediatrics, Seinäjoki Central Hospital, Seinäjoki, Finland
- City of Turku, Welfare Division, Preventive Healthcare, Turku, Finland
| | - Riikka E. Mäkitie
- Folkhälsan Research Center, Genetics Research Program, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Molecular Endocrinology Laboratory, Department of Medicine, Hammersmith Campus, Imperial College London, London, United Kingdom
| | - Heli Viljakainen
- Folkhälsan Research Center, Genetics Research Program, Helsinki, Finland
- The Department of Food and Nutrition, University of Helsinki, Helsinki, Finland
| | - Anders Kämpe
- Department of Molecular Medicine and Surgery, Karolinska Institutet, and Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Päivi Tossavainen
- Department of Children and Adolescents, PEDEGO Research Unit, University of Oulu, Oulu, Finland
| | - Marita Lipsanen-Nyman
- Children's Hospital, Helsinki University Hospital, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Minna Pekkinen
- Children's Hospital, Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Genetics Research Program, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Outi Mäkitie
- Children's Hospital, Helsinki University Hospital, Helsinki, Finland
- Folkhälsan Research Center, Genetics Research Program, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Molecular Medicine and Surgery, Karolinska Institutet, and Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
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35
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Liang C, Carrel D, Omelchenko A, Kim H, Patel A, Fanget I, Firestein BL. Cortical Neuron Migration and Dendrite Morphology are Regulated by Carboxypeptidase E. Cereb Cortex 2019; 29:2890-2903. [PMID: 29982499 PMCID: PMC6611459 DOI: 10.1093/cercor/bhy155] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 06/08/2018] [Accepted: 06/12/2018] [Indexed: 12/28/2022] Open
Abstract
Higher brain function relies on proper development of the cerebral cortex, including correct positioning of neurons and dendrite morphology. Disruptions in these processes may result in various neurocognitive disorders. Mutations in the CPE gene, which encodes carboxypeptidase E (CPE), have been linked to depression and intellectual disability. However, it remains unclear whether CPE is involved in early brain development and in turn contributes to the pathophysiology of neurocognitive disorders. Here, we investigate the effects of CPE knockdown on early brain development and explore the functional significance of the interaction between CPE and its binding partner p150Glued. We demonstrate that CPE is required for cortical neuron migration and dendrite arborization. Furthermore, we show that expression of CPE-C10 redistributes p150Glued from the centrosome and that disruption of CPE interaction with p150Glued leads to abnormal neuronal migration and dendrite morphology, suggesting that a complex between CPE and p150Glued is necessary for proper neurodevelopment.
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Affiliation(s)
- Chen Liang
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
- Molecular Biosciences Graduate Program, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
| | - Damien Carrel
- Neurophotonics Laboratory, Université Paris Descartes, Sorbonne Paris Cité, Centre National de la Recherche Scientifique UMR 8250, Paris, France
| | - Anton Omelchenko
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
- Neuroscience Graduate Program, Rutgers, The State University of New Jersey, 683 Hoes Lane West, USA
| | - Hyuck Kim
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
| | - Aashini Patel
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
| | - Isabelle Fanget
- Neurophotonics Laboratory, Université Paris Descartes, Sorbonne Paris Cité, Centre National de la Recherche Scientifique UMR 8250, Paris, France
| | - Bonnie L Firestein
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, 604 Allison Road, Piscataway, NJ, USA
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36
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Xiao L, Yang X, Loh YP. Neurotrophic, Gene Regulation, and Cognitive Functions of Carboxypeptidase E-Neurotrophic Factor-α1 and Its Variants. Front Neurosci 2019; 13:243. [PMID: 30941009 PMCID: PMC6433828 DOI: 10.3389/fnins.2019.00243] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/01/2019] [Indexed: 12/13/2022] Open
Abstract
Carboxypeptidase E, also known as neurotrophic factor-α1 (CPE-NFα1), was first discovered as an exopeptidase and is known to work by cleaving C-terminal basic amino acids from prohormone intermediates to produce mature peptide hormones and neuropeptides in the endocrine and central nervous systems, respectively. CPE-NFα1 also plays a critical role in prohormone sorting and secretory vesicle transportation. Recently, emerging studies have indicated that CPE-NFα1 exerts multiple non-enzymatic physiological roles in maintaining normal central nervous system function and in neurodevelopment. This includes potent neuroprotective and anti-depressant activities, as well as stem cell differentiation functions. In addition, N-terminal truncated variants of CPE-NFα1 have been identified to regulate expression of important neurodevelopmental genes. This mini-review summarizes recent advances in understanding the mechanisms underlying CPE-NFα1’s function in neuroprotection during stress and aspects of neurodevelopment.
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Affiliation(s)
- Lan Xiao
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Xuyu Yang
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Y Peng Loh
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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Tam V, Turcotte M, Meyre D. Established and emerging strategies to crack the genetic code of obesity. Obes Rev 2019; 20:212-240. [PMID: 30353704 DOI: 10.1111/obr.12770] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/11/2022]
Abstract
Tremendous progress has been made in the genetic elucidation of obesity over the past two decades, driven largely by technological, methodological and organizational innovations. Current strategies for identifying obesity-predisposing loci/genes, including cytogenetics, linkage analysis, homozygosity mapping, admixture mapping, candidate gene studies, genome-wide association studies, custom genotyping arrays, whole-exome sequencing and targeted exome sequencing, have achieved differing levels of success, and the identified loci in aggregate explain only a modest fraction of the estimated heritability of obesity. This review outlines the successes and limitations of these approaches and proposes novel strategies, including the use of exceptionally large sample sizes, the study of diverse ethnic groups and deep phenotypes and the application of innovative methods and study designs, to identify the remaining obesity-predisposing genes. The use of both established and emerging strategies has the potential to crack the genetic code of obesity in the not-too-distant future. The resulting knowledge is likely to yield improvements in obesity prediction, prevention and care.
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Affiliation(s)
- V Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - M Turcotte
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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DiStefano JK, Kingsley CB. Identification of Disease Susceptibility Alleles in the Next Generation Sequencing Era. Methods Mol Biol 2018; 1706:3-16. [PMID: 29423790 DOI: 10.1007/978-1-4939-7471-9_1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The development of next generation sequencing (NGS) technologies has transformed the study of human genetic variation. In less than a decade, NGS has facilitated the discovery of causal mutations in both rare, monogenic diseases and common, heterogeneous disorders, leading to unprecedented improvements in disease diagnosis and treatment strategies. Given the rapid evolution of NGS platforms, it is now possible to analyze whole genomes and exomes quickly and affordably. Further, emerging NGS applications, such as single-cell sequencing, have the power to address specific issues like somatic variation, which is yielding new insights into the role of somatic mutations in cancer and late-onset diseases. Despite limitations associated with current iterations of NGS technologies, the impact of this approach on identifying disease-causing variants has been significant. This chapter provides an overview of several NGS platforms and applications and discusses how these technologies can be used in concert with experimental and computational strategies to identify variants with a causative effect on disease development and progression.
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Affiliation(s)
- Johanna K DiStefano
- Translational Genomics Research Institute, 445 N 5th Street, Phoenix, AZ, 85004, USA.
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39
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Chen YC, Taylor AJ, Verchere CB. Islet prohormone processing in health and disease. Diabetes Obes Metab 2018; 20 Suppl 2:64-76. [PMID: 30230179 DOI: 10.1111/dom.13401] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 05/30/2018] [Accepted: 05/30/2018] [Indexed: 12/15/2022]
Abstract
Biosynthesis of peptide hormones by pancreatic islet endocrine cells is a tightly orchestrated process that is critical for metabolic homeostasis. Like neuroendocrine peptides, insulin and other islet hormones are first synthesized as larger precursor molecules that are processed to their mature secreted products through a series of proteolytic cleavages, mediated by the prohormone convertases Pc1/3 and Pc2, and carboxypeptidase E. Additional posttranslational modifications including C-terminal amidation of the β-cell peptide islet amyloid polypeptide (IAPP) by peptidyl-glycine α-amidating monooxygenase (Pam) may also occur. Genome-wide association studies (GWAS) have showed genetic linkage of these processing enzymes to obesity, β-cell dysfunction, and type 2 diabetes (T2D), pointing to their important roles in metabolism and blood glucose regulation. In both type 1 diabetes (T1D) and T2D, and in the face of metabolic or inflammatory stresses, islet prohormone processing may become impaired; indeed elevated proinsulin:insulin (PI:I) ratios are a hallmark of the β-cell dysfunction in T2D. Recent studies suggest that genetic or acquired defects in proIAPP processing may lead to the production and secretion of incompletely processed forms of proIAPP that could contribute to T2D pathogenesis, and additionally that impaired processing of both PI and proIAPP may be characteristic of β-cell dysfunction in T1D. In islet α-cells, the prohormone proglucagon is normally processed to bioactive glucagon by Pc2 but may express Pc1/3 under certain conditions leading to production of GLP-1(7-36NH2 ). A better understanding of how β-cell processing of PI and proIAPP, as well as α-cell processing of proglucagon, are impacted by genetic susceptibility and in the face of diabetogenic stresses, may lead to new therapeutic approaches for improving islet function in diabetes.
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Affiliation(s)
- Yi-Chun Chen
- Department of Surgery, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
| | - Austin J Taylor
- Department of Surgery, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
| | - C Bruce Verchere
- Department of Surgery, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, BC Children's Hospital Research Institute and University of British Columbia, Vancouver, British Columbia, Canada
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Xiao L, Yang X, Sharma VK, Loh YP. Cloning, gene regulation, and neuronal proliferation functions of novel N-terminal-truncated carboxypeptidase E/neurotrophic factor-αl variants in embryonic mouse brain. FASEB J 2018; 33:808-820. [PMID: 30063439 DOI: 10.1096/fj.201800359r] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Carboxypeptidase E (CPE), an exopeptidase involved in proneuropeptide processing, is also a neurotrophic factor, named neurotrophic factor-α1 (NF-α1) and has important roles in neuroprotection, stem cell differentiation, and neurite outgrowth, independent of enzymatic activity. Additionally, an N-terminal-truncated CPE/NF-α1 variant, (CPE/NF-α1)-ΔN, proposed from bioinformatic analysis of GenBank (National Center for Biotechnology Information, Bethesda, MD, USA) DNA sequences and encoding a 40-kDa protein, has been found to be exclusively expressed in embryonic neurons. To investigate the function of (CPE/NF-α1)-ΔN in neurodevelopment, we first cloned (CPE/NF-α1)-ΔN transcripts from an embryonic mouse brain. A rapid amplification of cDNA ends assay, DNA sequencing, and Northern blot revealed 1.9- and 1.73-kb transcripts, which encoded 47- and 40-kDa (CPE/NF-α1)-ΔN proteins, respectively. Those proteins were expressed in embryonic mouse brain. Expression of the 2 (CPE/NF-α1)-ΔN mRNAs surged at embryonic d 10.5, correlating with the time of neurogenesis in the developing brain and also at postnatal d 1. HT22 cells, a mouse hippocampal cell line, transduced with 40 kDa (CPE/NF-α1)-ΔN up-regulated expression of genes involved in embryonic neurodevelopment: insulin-like growth factor binding protein 2 ( IGFBP2), death-associated protein 1, and ephrin A1, which regulate proliferation, programmed cell death, and neuronal migration, respectively. HT22 cells and embryonic cortical neurons overexpressing 40 kDa (CPE/NF-α1)-ΔN exhibited enhanced proliferation, which was inhibited by IGFBP2 short interfering RNA treatment. Thus, 40 kDa (CPE/NF-α1)-ΔN has an important, enzymatically independent role in the regulation of genes critical for neurodevelopment.-Xiao, L., Yang, X., Sharma, V. K., Loh, Y. P. Cloning, gene regulation, and neuronal proliferation functions of novel N-terminal-truncated carboxypeptidase E/neurotrophic factor-αl variants in embryonic mouse brain.
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Affiliation(s)
- Lan Xiao
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Xuyu Yang
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Vinay Kumar Sharma
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Y Peng Loh
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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Kleinendorst L, Massink MPG, Cooiman MI, Savas M, van der Baan-Slootweg OH, Roelants RJ, Janssen ICM, Meijers-Heijboer HJ, Knoers NVAM, Ploos van Amstel HK, van Rossum EFC, van den Akker ELT, van Haaften G, van der Zwaag B, van Haelst MM. Genetic obesity: next-generation sequencing results of 1230 patients with obesity. J Med Genet 2018; 55:578-586. [PMID: 29970488 DOI: 10.1136/jmedgenet-2018-105315] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/21/2018] [Accepted: 06/10/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Obesity is a global and severe health problem. Due to genetic heterogeneity, the identification of genetic defects in patients with obesity can be time consuming and costly. Therefore, we developed a custom diagnostic targeted next-generation sequencing (NGS)-based analysis to simultaneously identify mutations in 52 obesity-related genes. The aim of this study was to assess the diagnostic yield of this approach in patients with suspected genetic obesity. METHODS DNA of 1230 patients with obesity (median BMI adults 43.6 kg/m2; median body mass index-SD children +3.4 SD) was analysed in the genome diagnostics section of the Department of Genetics of the UMC Utrecht (The Netherlands) by targeted analysis of 52 obesity-related genes. RESULTS In 48 patients pathogenic mutations confirming the clinical diagnosis were detected. The majority of these were observed in the MC4R gene (18/48). In an additional 67 patients a probable pathogenic mutation was identified, necessitating further analysis to confirm the clinical relevance. CONCLUSIONS NGS-based gene panel analysis in patients with obesity led to a definitive diagnosis of a genetic obesity disorder in 3.9% of obese probands, and a possible diagnosis in an additional 5.4% of obese probands. The highest yield was achieved in a selected paediatric subgroup, establishing a definitive diagnosis in 12 out of 164 children with severe early onset obesity (7.3%). These findings give a realistic insight in the diagnostic yield of genetic testing for patients with obesity and could help these patients to receive (future) personalised treatment.
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Affiliation(s)
- Lotte Kleinendorst
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands
| | - Maarten P G Massink
- Department of Genetics, Universitair Medisch Centrum Utrecht, Utrecht, The Netherlands
| | - Mellody I Cooiman
- Departmentof Bariatric Surgery, Rijnstate Hospital, Arnhem, The Netherlands
| | - Mesut Savas
- Department of Internal Medicine, division of Endocrinology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | | | - Roosje J Roelants
- Child Obesity Expert Centre Amsterdam, Women and Child Clinic, VU Medical Center (previously Deptartment of Pediatrics Slotervaartziekenhuis), Amsterdam, The Netherlands
| | - Ignace C M Janssen
- Departmentof Bariatric Surgery, Rijnstate Hospital, Arnhem, The Netherlands
| | - Hanne J Meijers-Heijboer
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands.,Department of Clinical Genetics, VU Medical Center, Amsterdam, The Netherlands
| | - Nine V A M Knoers
- Department of Genetics, Universitair Medisch Centrum Utrecht, Utrecht, The Netherlands
| | | | - Elisabeth F C van Rossum
- Department of Internal Medicine, division of Endocrinology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Erica L T van den Akker
- Department of Pediatric Endocrinology, Sophia kinderziekenhuis Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Gijs van Haaften
- Department of Genetics, Universitair Medisch Centrum Utrecht, Utrecht, The Netherlands
| | - Bert van der Zwaag
- Department of Genetics, Universitair Medisch Centrum Utrecht, Utrecht, The Netherlands
| | - Mieke M van Haelst
- Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands.,Department of Clinical Genetics, VU Medical Center, Amsterdam, The Netherlands
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Ayers KL, Glicksberg BS, Garfield AS, Longerich S, White JA, Yang P, Du L, Chittenden TW, Gulcher JR, Roy S, Fiedorek F, Gottesdiener K, Cohen S, North KE, Schadt EE, Li SD, Chen R, Van der Ploeg LHT. Melanocortin 4 Receptor Pathway Dysfunction in Obesity: Patient Stratification Aimed at MC4R Agonist Treatment. J Clin Endocrinol Metab 2018; 103:2601-2612. [PMID: 29726959 PMCID: PMC7263790 DOI: 10.1210/jc.2018-00258] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 04/27/2018] [Indexed: 01/03/2023]
Abstract
CONTEXT The hypothalamic melanocortin 4 receptor (MC4R) pathway serves a critical role in regulating body weight. Loss of function (LoF) mutations in the MC4R pathway, including mutations in the pro-opiomelanocortin (POMC), prohormone convertase 1 (PCSK1), leptin receptor (LEPR), or MC4R genes, have been shown to cause early-onset severe obesity. METHODS Through a comprehensive epidemiological analysis of known and predicted LoF variants in the POMC, PCSK1, and LEPR genes, we sought to estimate the number of US individuals with biallelic MC4R pathway LoF variants. RESULTS We predict ~650 α-melanocyte-stimulating hormone (MSH)/POMC, 8500 PCSK1, and 3600 LEPR homozygous and compound heterozygous individuals in the United States, cumulatively enumerating >12,800 MC4R pathway-deficient obese patients. Few of these variants have been genetically diagnosed to date. These estimates increase when we include a small subset of less rare variants: β-MSH/POMC,PCSK1 N221D, and a PCSK1 LoF variant (T640A). To further define the MC4R pathway and its potential impact on obesity, we tested associations between body mass index (BMI) and LoF mutation burden in the POMC, PCSK1, and LEPR genes in various populations. We show that the cumulative allele burden in individuals with two or more LoF alleles in one or more genes in the MC4R pathway are predisposed to a higher BMI than noncarriers or heterozygous LoF carriers with a defect in only one gene. CONCLUSIONS Our analysis represents a genetically rationalized study of the hypothalamic MC4R pathway aimed at genetic patient stratification to determine which obese subpopulations should be studied to elucidate MC4R agonist (e.g., setmelanotide) treatment responsiveness.
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Affiliation(s)
- Kristin L Ayers
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, New York
- Sema4, Stamford, Connecticut
| | - Benjamin S Glicksberg
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, New York
| | | | | | | | | | - Lei Du
- WuXiNextCode, Cambridge, Massachusetts
| | | | | | - Sophie Roy
- Rhythm Pharmaceuticals, Boston, Massachusetts
| | | | | | | | - Kari E North
- University of North Carolina, Chapel Hill, North Carolina
| | - Eric E Schadt
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, New York
- Sema4, Stamford, Connecticut
| | - Shuyu D Li
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, New York
- Sema4, Stamford, Connecticut
- Correspondence and Reprint Requests: Shuyu D. Li, PhD, or Rong Chen, PhD, Icahn School of Medicine at Mount Sinai, 1255 5th Avenue, New York, New York 10029. E-mail: or; or Lex H. T. Van der Ploeg, PhD, Rhythm Pharmaceuticals, 500 Boylston Street, Boston, Massachusetts 02116. E-mail:
| | - Rong Chen
- Department of Genetics and Genomic Sciences, Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, New York
- Sema4, Stamford, Connecticut
- Correspondence and Reprint Requests: Shuyu D. Li, PhD, or Rong Chen, PhD, Icahn School of Medicine at Mount Sinai, 1255 5th Avenue, New York, New York 10029. E-mail: or; or Lex H. T. Van der Ploeg, PhD, Rhythm Pharmaceuticals, 500 Boylston Street, Boston, Massachusetts 02116. E-mail:
| | - Lex H T Van der Ploeg
- Rhythm Pharmaceuticals, Boston, Massachusetts
- Correspondence and Reprint Requests: Shuyu D. Li, PhD, or Rong Chen, PhD, Icahn School of Medicine at Mount Sinai, 1255 5th Avenue, New York, New York 10029. E-mail: or; or Lex H. T. Van der Ploeg, PhD, Rhythm Pharmaceuticals, 500 Boylston Street, Boston, Massachusetts 02116. E-mail:
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Acosta-Montaño P, García-González V. Effects of Dietary Fatty Acids in Pancreatic Beta Cell Metabolism, Implications in Homeostasis. Nutrients 2018; 10:nu10040393. [PMID: 29565831 PMCID: PMC5946178 DOI: 10.3390/nu10040393] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 03/02/2018] [Accepted: 03/13/2018] [Indexed: 12/26/2022] Open
Abstract
Fatty acids are involved in several metabolic processes, including the development of metabolic and cardiovascular diseases. In recent years a disease that has received escalated interest is type 2 diabetes (T2D). Many contributing factors including a high-caloric diet rich in dietary saturated fats have been broadly characterized as triggers of T2D. Insulin resistance resulting from a high saturated fat diet leads to alterations in lipid cellular intake and accumulation which generate lipotoxic conditions, a key phenomenon in the metabolism of β-cells. Alternatively, unsaturated fatty acids have been described to show opposite effects in pancreatic β-cells. The purpose of this work is to perform a critical analysis of the complex role of saturated and unsaturated fatty acids in β-cell metabolism. We discuss the diverse effects main dietary fatty acids have upon pancreatic β-cell metabolism as a key factor to maintain homeostasis by focusing in the cellular and molecular mechanisms involved in the development and progression of T2D. For instance, modifications in protein homeostasis as well as the intracellular management of lipid metabolism which are associated with inflammatory pathways. These conditions initiate critical metabolic rearrangements, that in turn have repercussions on insulin β-cell metabolism. This review allows an integral and broad understanding of different functions of fatty acids inside β-cells, being important metabolites for novel therapeutic targets in T2D treatment.
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Affiliation(s)
- Paloma Acosta-Montaño
- Departamento de Bioquímica, Facultad de Medicina Mexicali, Universidad Autónoma de Baja California, Mexicali 21000, Mexico.
| | - Víctor García-González
- Departamento de Bioquímica, Facultad de Medicina Mexicali, Universidad Autónoma de Baja California, Mexicali 21000, Mexico.
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Saeed S, Arslan M, Froguel P. Genetics of Obesity in Consanguineous Populations: Toward Precision Medicine and the Discovery of Novel Obesity Genes. Obesity (Silver Spring) 2018; 26:474-484. [PMID: 29464904 DOI: 10.1002/oby.22064] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2016] [Revised: 09/05/2017] [Accepted: 09/30/2017] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Consanguinity has been instrumental in the elucidation of many Mendelian genetic diseases. Here, the unique advantage of consanguineous populations was considered in the quest for genes causing obesity. METHODS PubMed was searched for articles relevant to consanguinity and obesity published between 1995 and 2016. Some earlier articles of interest were also consulted. RESULTS Although obesity is the most heritable disorder, even in outbred populations, only 2% to 5% of severe obesity cases have so far been proven to be caused by single gene mutations. In some highly consanguineous populations, a remarkably higher proportion of obesity cases because of known and novel monogenic variants has been identified (up to 30%). CONCLUSIONS Combining the power conferred by consanguinity with current large-capacity sequencing techniques should bring new genetic factors and molecular mechanisms to the fore, unveiling a large part of the yet-elusive neurohumoral circuitry involved in the regulation of energy homeostasis and appetite. Importantly, the undertaking of such initiatives is destined to unfold novel targets for the development of precision medicine relevant to different forms of obesity.
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Affiliation(s)
- Sadia Saeed
- Department of Genomics of Common Disease, Imperial College London, London, UK
- CNRS, Pasteur Institute of Lille, University of Lille, Lille, France
| | - Muhammad Arslan
- Centre for Research in Molecular Medicine, The University of Lahore, Lahore, Pakistan
- Department of Biological Sciences, Forman Christian College, Lahore, Pakistan
| | - Philippe Froguel
- Department of Genomics of Common Disease, Imperial College London, London, UK
- CNRS, Pasteur Institute of Lille, University of Lille, Lille, France
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Fricker LD. Carboxypeptidase E and the Identification of Novel Neuropeptides as Potential Therapeutic Targets. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 82:85-102. [PMID: 29413529 DOI: 10.1016/bs.apha.2017.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Peptides and small molecules that bind to peptide receptors are important classes of drugs that are used for a wide variety of different applications. The search for novel neuropeptides traditionally involved a time-consuming approach to purify each peptide to homogeneity and determine its amino acid sequence. The discovery in the 1980s of enkephalin convertase/carboxypeptidase E (CPE), and the observation that this enzyme was involved in the production of nearly every known neuropeptide led to the idea for a one-step affinity purification of CPE substrates. This approach was successfully used to isolate hundreds of known neuropeptides in mouse brain, as well as over a dozen novel peptides. Some of the novel peptides found using this approach are among the most abundant peptides present in brain, but had not been previously identified by traditional approaches. Recently, receptors for two of the novel peptides have been identified, confirming their role as neuropeptides that function in cell-cell signaling. Small molecules that bind to one of these receptors have been developed and found to significantly reduce food intake and anxiety-like behavior in an animal model. This review describes the entire project, from discovery of CPE to the novel peptides and their receptors.
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Affiliation(s)
- Lloyd D Fricker
- Albert Einstein College of Medicine, Bronx, NY, United States.
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46
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Ji L, Wu HT, Qin XY, Lan R. Dissecting carboxypeptidase E: properties, functions and pathophysiological roles in disease. Endocr Connect 2017; 6:R18-R38. [PMID: 28348001 PMCID: PMC5434747 DOI: 10.1530/ec-17-0020] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 03/27/2017] [Indexed: 01/02/2023]
Abstract
Since discovery in 1982, carboxypeptidase E (CPE) has been shown to be involved in the biosynthesis of a wide range of neuropeptides and peptide hormones in endocrine tissues, and in the nervous system. This protein is produced from pro-CPE and exists in soluble and membrane forms. Membrane CPE mediates the targeting of prohormones to the regulated secretory pathway, while soluble CPE acts as an exopeptidase and cleaves C-terminal basic residues from peptide intermediates to generate bioactive peptides. CPE also participates in protein internalization, vesicle transport and regulation of signaling pathways. Therefore, in two types of CPE mutant mice, Cpefat/Cpefat and Cpe knockout, loss of normal CPE leads to a lot of disorders, including diabetes, hyperproinsulinemia, low bone mineral density and deficits in learning and memory. In addition, the potential roles of CPE and ΔN-CPE, an N-terminal truncated form, in tumorigenesis and diagnosis were also addressed. Herein, we focus on dissecting the pathophysiological roles of CPE in the endocrine and nervous systems, and related diseases.
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Affiliation(s)
- Lin Ji
- Department of Cell Biology & Medical GeneticsSchool of Medicine, Shenzhen University, Shenzhen, China
| | - Huan-Tong Wu
- Beijing Engineering Research Center of Food Environment and HealthCollege of Life & Environmental Sciences, Minzu University of China, Beijing, China
| | - Xiao-Yan Qin
- Beijing Engineering Research Center of Food Environment and HealthCollege of Life & Environmental Sciences, Minzu University of China, Beijing, China
| | - Rongfeng Lan
- Department of Cell Biology & Medical GeneticsSchool of Medicine, Shenzhen University, Shenzhen, China
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Xiao L, Chang SY, Xiong ZG, Selveraj P, Peng Loh Y. Absence of Carboxypeptidase E/Neurotrophic Factor-Α1 in Knock-Out Mice Leads to Dysfunction of BDNF-TRKB Signaling in Hippocampus. J Mol Neurosci 2017; 62:79-87. [PMID: 28386642 DOI: 10.1007/s12031-017-0914-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 03/29/2017] [Indexed: 12/12/2022]
Abstract
Carboxypeptidase E (CPE), first discovered as a prohormone processing enzyme, has also now been shown to be a secreted neurotrophic factor (neurotrophic factor-α1, NF-α1) that acts extracellularly as a signaling molecule to mediate neuroprotection, cortical stem cell differentiation, and antidepressive-like behavior in mice. Since brain-derived neurotrophic factor (BDNF) has very similar trophic functions, and its processing from pro-BDNF involves intracellular sorting of pro-BDNF to the regulated secretory pathway by CPE acting as a sorting receptor, we investigated whether the lack of CPE/NF-α1 would affect BDNF-TrkB signaling in mice. Previous studies have shown that CPE/NF-α1 knock-out (KO) mice exhibited severe neurodegeneration of the hippocampal CA3 region which raises the question of why other neurotrophic factors such as BDNF could not compensate for the deficiency of CPE. Here, we show that the expressions of pro-BDNF mRNA and protein in hippocampus of CPE-KO mice were similar to WT mice, but mature BDNF was ∼40% less in the CPE-KO mice, suggesting decreased intracellular processing of pro-BDNF. Furthermore, TrkB receptor levels were similar in both genotypes, but there was significantly decreased phosphorylation of TrkB receptor in the CPE-KO mice. Electrophysiological studies showed lack of formation of long-term potentiation in hippocampal slices of CPE-KO mice compared to WT mice, which was not rescued by application of BDNF, indicating dysfunction of the BDNF-TrkB signaling system. The CPE-KO mice showed normal postsynaptic AMPA response to kainate application in hippocampal slices and dissociated neurons. Our findings indicate that CPE/NF-α1 is essential for normal BDNF-TrkB signaling function in mouse hippocampus.
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Affiliation(s)
- Lan Xiao
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 49, Convent Drive, Bldg 49, Rm 6A-10, NICHD, NIH, Bethesda, MD, 20892, USA
| | - Su-Youne Chang
- Department of Neurologic Surgery and Physiology, Mayo Clinic, Rochester, MN, 55905, USA
| | - Zhi-Gang Xiong
- Department of Neurobiology, Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, 30310, USA
| | - Prabhuanand Selveraj
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 49, Convent Drive, Bldg 49, Rm 6A-10, NICHD, NIH, Bethesda, MD, 20892, USA
| | - Y Peng Loh
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 49, Convent Drive, Bldg 49, Rm 6A-10, NICHD, NIH, Bethesda, MD, 20892, USA.
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Cong L, Cheng Y, Cawley NX, Murthy SRK, Loh YP. A Novel Single Nucleotide T980C Polymorphism in the Human Carboxypeptidase E Gene Results in Loss of Neuroprotective Function. PLoS One 2017; 12:e0170169. [PMID: 28114332 PMCID: PMC5256889 DOI: 10.1371/journal.pone.0170169] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 12/30/2016] [Indexed: 11/18/2022] Open
Abstract
Report of a human with a homozygous truncating null mutation of the Carboxypeptidase E (CPE) gene with endocrinological and neurological deficits prompted us to search for other mutations in the human CPE gene that might be linked to disease. We searched an EST database and identified from a small population of patients, a novel T to C single nucleotide polymorphism (SNP) in the CPE gene at bp980 of exon 4, herein called TC-CPE. This introduces a tryptophan to arginine (W235R) mutation in the catalytic domain of human CPE protein. Over-expression of TC-CPE in N2A cells, a neuroendocrine cell line, showed that it was synthesized, but was found in lesser amounts compared to over-expressed WT-CPE in these cells. Furthermore, TC-CPE was secreted poorly from these N2A cells. The levels of TC-CPE were significantly increased after the N2A cells were treated with MG132 (a proteasome inhibitor), suggesting that TC-CPE was targeted to proteasomes for degradation in N2A cells. In addition, TC-CPE induced ER stress as demonstrated by the increased expression of CHOP in N2A cells. Double labeling of CPE and calnexin (and ER marker) suggested the accumulation of TC-CPE in the ER, and the accumulation appears to be enhanced by the treatment of MG132 in the cells. Moreover, the secreted levels of TC-CPE were not affected by the treatment of MG132 in the cells. Over-expression studies revealed that while N2A cells transfected with WT-CPE showed reduced cytotoxicity when challenged with H2O2 compared to cells expressing an empty vector, cells transfected with TC-CPE had no effect. Furthermore, WT-CPE condition medium showed protective effect against oxidative stress, but not TC-CPE condition medium. Although co-expression of WT-CPE and TC-CPE in N2A cells resulted in the reduction in secretion of WT-CPE, co-expression of WT-CPE and TC-CPE did not significantly affect the protective effect of WT-CPE. Taken together, we have identified a novel SNP in the CPE gene which results in the loss of its neuroprotective function in cells and may confer neurological disorders in humans.
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Affiliation(s)
- Lin Cong
- Department of General Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Yong Cheng
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Niamh X. Cawley
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Saravana R. K. Murthy
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
| | - Y. Peng Loh
- Section on Cellular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States of America
- * E-mail:
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Abstract
Obesity is a complex, heritable trait influenced by the interplay of genetics, epigenetics, metagenomics and the environment. With the increasing access to high precision diagnostic tools for genetic investigations, numerous genes influencing the phenotype have been identified, especially in early onset severe obesity. This review summarizes the current knowledge on the known genetic causes of obesity and the available therapeutic options. Furthermore, we discuss the role and potential mechanism of epigenetic changes that may be involved as mediators of the environmental influences and that may provide future opportunities for intervention.
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Affiliation(s)
- Vidhu V Thaker
- Division of Molecular Genetics, Department of Pediatrics, Columbia University Medical Center, New York, NY
- Harvard Medical School, Boston, MA
- Division of Endocrinology, Boston Children's Hospital, Boston, MA
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50
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Thaker VV. GENETIC AND EPIGENETIC CAUSES OF OBESITY. ADOLESCENT MEDICINE: STATE OF THE ART REVIEWS 2017; 28:379-405. [PMID: 30416642 PMCID: PMC6226269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Obesity is a complex, heritable trait influenced by the interplay of genetics, epigenetics, metagenomics and the environment. With the increasing access to high precision diagnostic tools for genetic investigations, numerous genes influencing the phenotype have been identified, especially in early onset severe obesity. This review summarizes the current knowledge on the known genetic causes of obesity and the available therapeutic options. Furthermore, we discuss the role and potential mechanism of epigenetic changes that may be involved as mediators of the environmental influences and that may provide future opportunities for intervention.
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Affiliation(s)
- Vidhu V Thaker
- Division of Molecular Genetics, Department of Pediatrics, Columbia University Medical Center, New York, NY
- Harvard Medical School, Boston, MA
- Division of Endocrinology, Boston Children's Hospital, Boston, MA
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