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Yau B, Madsen S, Nelson ME, Cooke KC, Fritzen AM, Thorius IH, Stöckli J, James DE, Kebede MA. Genetics and diet shape the relationship between islet function and whole body metabolism. Am J Physiol Endocrinol Metab 2024; 326:E663-E672. [PMID: 38568150 DOI: 10.1152/ajpendo.00060.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/28/2024] [Accepted: 03/30/2024] [Indexed: 05/08/2024]
Abstract
Despite the fact that genes and the environment are known to play a central role in islet function, our knowledge of how these parameters interact to modulate insulin secretory function remains relatively poor. Presently, we performed ex vivo glucose-stimulated insulin secretion and insulin content assays in islets of 213 mice from 13 inbred mouse strains on chow, Western diet (WD), and a high-fat, carbohydrate-free (KETO) diet. Strikingly, among these 13 strains, islets from the commonly used C57BL/6J mouse strain were the least glucose responsive. Using matched metabolic phenotyping data, we performed correlation analyses of isolated islet parameters and found a positive correlation between basal and glucose-stimulated insulin secretion, but no relationship between insulin secretion and insulin content. Using in vivo metabolic measures, we found that glucose tolerance determines the relationship between ex vivo islet insulin secretion and plasma insulin levels. Finally, we showed that islet glucose-stimulated insulin secretion decreased with KETO in almost all strains, concomitant with broader phenotypic changes, such as increased adiposity and glucose intolerance. This is an important finding as it should caution against the application of KETO diet for beta-cell health. Together these data offer key insights into the intersection of diet and genetic background on islet function and whole body glucose metabolism.NEW & NOTEWORTHY Thirteen strains of mice on chow, Western diet, and high-fat, carbohydrate-free (KETO), correlating whole body phenotypes to ex vivo pancreatic islet functional measurements, were used. The study finds a huge spectrum of functional islet responses and insulin phenotypes across all strains and diets, with the ubiquitous C57Bl/6J mouse exhibiting the lowest secretory response of all strains, highlighting the overall importance of considering genetic background when investigating islet function. Ex vivo basal and stimulated insulin secretion are correlated in the islet, and KETO imparts widescale downregulation of islet insulin secretion.
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Affiliation(s)
- Belinda Yau
- School of Medical Science, Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, Australia
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Søren Madsen
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Marin E Nelson
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Kristen C Cooke
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Andreas M Fritzen
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Ida H Thorius
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Jacqueline Stöckli
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - David E James
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
- School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
- Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, Australia
| | - Melkam A Kebede
- School of Medical Science, Faculty of Medicine and Health, University of Sydney, Camperdown, New South Wales, Australia
- Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
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Kalnytska O, Qvist P, Kunz S, Conrad T, Willnow TE, Schmidt V. SORCS2 activity in pancreatic α-cells safeguards insulin granule formation and release from glucose-stressed β-cells. iScience 2024; 27:108725. [PMID: 38226160 PMCID: PMC10788290 DOI: 10.1016/j.isci.2023.108725] [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: 06/09/2023] [Revised: 09/18/2023] [Accepted: 12/11/2023] [Indexed: 01/17/2024] Open
Abstract
Sorting receptor SORCS2 is a stress-response factor protecting neurons from acute insults, such as during epilepsy. SORCS2 is also expressed in the pancreas, yet its action in this tissue remains unknown. Combining metabolic studies in SORCS2-deficient mice with ex vivo functional analyses and single-cell transcriptomics of pancreatic tissues, we identified a role for SORCS2 in protective stress response in pancreatic islets, essential to sustain insulin release. We show that SORCS2 is predominantly expressed in islet alpha cells. Loss of expression coincides with inability of these cells to produce osteopontin, a secreted factor that facilitates insulin release from stressed beta cells. In line with diminished osteopontin levels, beta cells in SORCS2-deficient islets show gene expression patterns indicative of aggravated cell stress, and exhibit defects in insulin granule maturation and a blunted glucose response. These findings corroborate a function for SORCS2 in protective stress response that extends to metabolism.
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Affiliation(s)
- Oleksandra Kalnytska
- Molecular Cardiovascular Research, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
- Charité – Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Per Qvist
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Séverine Kunz
- Technology Platform for Electron Microscopy, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Thomas Conrad
- Genomics Technology Platform, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 10115 Berlin, Germany
| | - Thomas E. Willnow
- Molecular Cardiovascular Research, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
- Charité – Universitätsmedizin Berlin, 10117 Berlin, Germany
- Department of Biomedicine, Aarhus University, 8000 Aarhus, Denmark
| | - Vanessa Schmidt
- Molecular Cardiovascular Research, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
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Reichlmeir M, Canet-Pons J, Koepf G, Nurieva W, Duecker RP, Doering C, Abell K, Key J, Stokes MP, Zielen S, Schubert R, Ivics Z, Auburger G. In Cerebellar Atrophy of 12-Month-Old ATM-Null Mice, Transcriptome Upregulations Concern Most Neurotransmission and Neuropeptide Pathways, While Downregulations Affect Prominently Itpr1, Usp2 and Non-Coding RNA. Cells 2023; 12:2399. [PMID: 37830614 PMCID: PMC10572167 DOI: 10.3390/cells12192399] [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: 09/14/2023] [Revised: 09/29/2023] [Accepted: 10/01/2023] [Indexed: 10/14/2023] Open
Abstract
The autosomal recessive disorder Ataxia-Telangiectasia is caused by a dysfunction of the stress response protein, ATM. In the nucleus of proliferating cells, ATM senses DNA double-strand breaks and coordinates their repair. This role explains T-cell dysfunction and tumour risk. However, it remains unclear whether this function is relevant for postmitotic neurons and underlies cerebellar atrophy, since ATM is cytoplasmic in postmitotic neurons. Here, we used ATM-null mice that survived early immune deficits via bone-marrow transplantation, and that reached initial neurodegeneration stages at 12 months of age. Global cerebellar transcriptomics demonstrated that ATM depletion triggered upregulations in most neurotransmission and neuropeptide systems. Downregulated transcripts were found for the ATM interactome component Usp2, many non-coding RNAs, ataxia genes Itpr1, Grid2, immediate early genes and immunity factors. Allelic splice changes affected prominently the neuropeptide machinery, e.g., Oprm1. Validation experiments with stressors were performed in human neuroblastoma cells, where ATM was localised only to cytoplasm, similar to the brain. Effect confirmation in SH-SY5Y cells occurred after ATM depletion and osmotic stress better than nutrient/oxidative stress, but not after ATM kinase inhibition or DNA stressor bleomycin. Overall, we provide pioneer observations from a faithful A-T mouse model, which suggest general changes in synaptic and dense-core vesicle stress adaptation.
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Affiliation(s)
- Marina Reichlmeir
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (M.R.); (J.C.-P.); (J.K.)
| | - Júlia Canet-Pons
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (M.R.); (J.C.-P.); (J.K.)
| | - Gabriele Koepf
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (M.R.); (J.C.-P.); (J.K.)
| | - Wasifa Nurieva
- Transposition and Genome Engineering, Research Centre of the Division of Hematology, Gene and Cell Therapy, Paul Ehrlich Institute, 63225 Langen, Germany; (W.N.); (Z.I.)
| | - Ruth Pia Duecker
- Division of Pediatrics, Pulmonology, Allergology, Infectious Diseases and Gastroenterology, Children’s Hospital, University Hospital, Goethe-University, 60590 Frankfurt am Main, Germany; (R.P.D.); (S.Z.); (R.S.)
| | - Claudia Doering
- Dr. Senckenberg Institute of Pathology, University Hospital Frankfurt, 60590 Frankfurt am Main, Germany;
| | - Kathryn Abell
- Cell Signaling Technology, Inc., Danvers, MA 01923, USA; (K.A.); (M.P.S.)
| | - Jana Key
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (M.R.); (J.C.-P.); (J.K.)
| | - Matthew P. Stokes
- Cell Signaling Technology, Inc., Danvers, MA 01923, USA; (K.A.); (M.P.S.)
| | - Stefan Zielen
- Division of Pediatrics, Pulmonology, Allergology, Infectious Diseases and Gastroenterology, Children’s Hospital, University Hospital, Goethe-University, 60590 Frankfurt am Main, Germany; (R.P.D.); (S.Z.); (R.S.)
- Respiratory Research Institute, Medaimun GmbH, 60596 Frankfurt am Main, Germany
| | - Ralf Schubert
- Division of Pediatrics, Pulmonology, Allergology, Infectious Diseases and Gastroenterology, Children’s Hospital, University Hospital, Goethe-University, 60590 Frankfurt am Main, Germany; (R.P.D.); (S.Z.); (R.S.)
| | - Zoltán Ivics
- Transposition and Genome Engineering, Research Centre of the Division of Hematology, Gene and Cell Therapy, Paul Ehrlich Institute, 63225 Langen, Germany; (W.N.); (Z.I.)
| | - Georg Auburger
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (M.R.); (J.C.-P.); (J.K.)
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Klein M, Failla AV, Hermey G. Internally tagged Vps10p-domain receptors reveal uptake of the neurotrophin BDNF. J Biol Chem 2023; 299:105216. [PMID: 37660918 PMCID: PMC10540051 DOI: 10.1016/j.jbc.2023.105216] [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: 07/10/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 09/05/2023] Open
Abstract
The Vps10p-domain (Vps10p-D) receptor family consists of Sortilin, SorLA, SorCS1, SorCS2, and SorCS3. They mediate internalization and intracellular sorting of specific cargo in various cell types, but underlying molecular determinants are incompletely understood. Deciphering the dynamic intracellular itineraries of Vps10p-D receptors is crucial for understanding their role in physiological and cytopathological processes. However, studying their spatial and temporal dynamics by live imaging has been challenging so far, as terminal tagging with fluorophores presumably impedes several of their protein interactions and thus functions. Here, we addressed the lack of appropriate tools and developed functional versions of all family members internally tagged in their ectodomains. We predict folding of the newly designed receptors by bioinformatics and show their exit from the endoplasmic reticulum. We examined their subcellular localization in immortalized cells and primary cultured neurons by immunocytochemistry and live imaging. This was, as far as known, identical to that of wt counterparts. We observed homodimerization of fluorophore-tagged SorCS2 by coimmunoprecipitation and fluorescence lifetime imaging, suggesting functional leucine-rich domains. Through ligand uptake experiments, live imaging and fluorescence lifetime imaging, we show for the first time that all Vps10p-D receptors interact with the neurotrophin brain-derived neurotrophic factor and mediate its uptake, indicating functionality of the Vps10p-Ds. In summary, we developed versions of all Vps10p-D receptors, with internal fluorophore tags that preserve several functions of the cytoplasmic and extracellular domains. These newly developed fluorophore-tagged receptors are likely to serve as powerful functional tools for accurate live studies of the individual cellular functions of Vps10p-D receptors.
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Affiliation(s)
- Marcel Klein
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | | | - Guido Hermey
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology Hamburg, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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Keller MP, Hudkins KL, Shalev A, Bhatnagar S, Kebede MA, Merrins MJ, Davis DB, Alpers CE, Kimple ME, Attie AD. What the BTBR/J mouse has taught us about diabetes and diabetic complications. iScience 2023; 26:107036. [PMID: 37360692 PMCID: PMC10285641 DOI: 10.1016/j.isci.2023.107036] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023] Open
Abstract
Human and mouse genetics have delivered numerous diabetogenic loci, but it is mainly through the use of animal models that the pathophysiological basis for their contribution to diabetes has been investigated. More than 20 years ago, we serendipidously identified a mouse strain that could serve as a model of obesity-prone type 2 diabetes, the BTBR (Black and Tan Brachyury) mouse (BTBR T+ Itpr3tf/J, 2018) carrying the Lepob mutation. We went on to discover that the BTBR-Lepob mouse is an excellent model of diabetic nephropathy and is now widely used by nephrologists in academia and the pharmaceutical industry. In this review, we describe the motivation for developing this animal model, the many genes identified and the insights about diabetes and diabetes complications derived from >100 studies conducted in this remarkable animal model.
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Affiliation(s)
- Mark P. Keller
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Kelly L. Hudkins
- Department of Pathology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Anath Shalev
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, AL 35294, UK
| | - Sushant Bhatnagar
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Alabama at Birmingham, Birmingham, AL 35294, UK
| | - Melkam A. Kebede
- School of Medical Sciences, Faculty of Medicine and Health, Charles Perkins Centre, University of Sydney, Camperdown, Sydney, NSW 2006, Australia
| | - Matthew J. Merrins
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Dawn Belt Davis
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Charles E. Alpers
- Department of Pathology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Michelle E. Kimple
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, USA
| | - Alan D. Attie
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Medicine, Division of Endocrinology, Diabetes, and Metabolism, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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Salasova A, Monti G, Andersen OM, Nykjaer A. Finding memo: versatile interactions of the VPS10p-Domain receptors in Alzheimer’s disease. Mol Neurodegener 2022; 17:74. [PMID: 36397124 PMCID: PMC9673319 DOI: 10.1186/s13024-022-00576-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 10/17/2022] [Indexed: 11/19/2022] Open
Abstract
The family of VPS10p-Domain (D) receptors comprises five members named SorLA, Sortilin, SorCS1, SorCS2 and SorCS3. While their physiological roles remain incompletely resolved, they have been recognized for their signaling engagements and trafficking abilities, navigating a number of molecules between endosome, Golgi compartments, and the cell surface. Strikingly, recent studies connected all the VPS10p-D receptors to Alzheimer’s disease (AD) development. In addition, they have been also associated with diseases comorbid with AD such as diabetes mellitus and major depressive disorder. This systematic review elaborates on genetic, functional, and mechanistic insights into how dysfunction in VPS10p-D receptors may contribute to AD etiology, AD onset diversity, and AD comorbidities. Starting with their functions in controlling cellular trafficking of amyloid precursor protein and the metabolism of the amyloid beta peptide, we present and exemplify how these receptors, despite being structurally similar, regulate various and distinct cellular events involved in AD. This includes a plethora of signaling crosstalks that impact on neuronal survival, neuronal wiring, neuronal polarity, and synaptic plasticity. Signaling activities of the VPS10p-D receptors are especially linked, but not limited to, the regulation of neuronal fitness and apoptosis via their physical interaction with pro- and mature neurotrophins and their receptors. By compiling the functional versatility of VPS10p-D receptors and their interactions with AD-related pathways, we aim to further propel the AD research towards VPS10p-D receptor family, knowledge that may lead to new diagnostic markers and therapeutic strategies for AD patients.
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SORLA mediates endocytic uptake of proIAPP and protects against islet amyloid deposition. Mol Metab 2022; 65:101585. [PMID: 36055578 PMCID: PMC9474563 DOI: 10.1016/j.molmet.2022.101585] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/27/2022] [Accepted: 08/25/2022] [Indexed: 11/20/2022] Open
Abstract
Objective Sorting-related receptor with type A repeats (SORLA) is a neuronal sorting receptor that prevents accumulation of amyloid-beta peptides, the main constituent of senile plaques in Alzheimer disease. Recent transcriptomic studies show that SORLA transcripts are also found in beta cells of pancreatic islets, yet the role of SORLA in islets is unknown. Based on its protective role in reducing the amyloid burden in the brain, we hypothesized that SORLA has a similar function in the pancreas via regulation of amyloid formation from islet amyloid polypeptide (IAPP). Methods We generated human IAPP transgenic mice lacking SORLA (hIAPP:SORLA KO) to assess the consequences of receptor deficiency for islet histopathology and function in vivo. Using both primary islet cells and cell lines, we further investigated the molecular mechanisms whereby SORLA controls the cellular metabolism and accumulation of IAPP. Results Loss of SORLA activity in hIAPP:SORLA KO resulted in a significant increase in islet amyloid deposits and associated islet cell death compared to hIAPP:SORLA WT animals. Aggravated islet amyloid deposition was observed in mice fed a normal chow diet, not requiring high-fat diet feeding typically needed to induce islet amyloidosis in mouse models. In vitro studies showed that SORLA binds to and mediates the endocytic uptake of proIAPP, but not mature IAPP, delivering the propeptide to an endolysosomal fate. Conclusions SORLA functions as a proIAPP-specific clearance receptor, protecting against islet amyloid deposition and associated cell death caused by IAPP. SORLA is an endocytic receptor for amyloidogenic peptides expressed in islet beta cells. SORLA mediates cellular clearance of proIAPP. Loss of SORLA activity in mouse models causes spontaneous islet amyloid deposition.
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Lee K, Chan JY, Liang C, Ip CK, Shi YC, Herzog H, Hughes WE, Bensellam M, Delghingaro-Augusto V, Koina ME, Nolan CJ, Laybutt DR. XBP1 maintains beta cell identity, represses beta-to-alpha cell transdifferentiation and protects against diabetic beta cell failure during metabolic stress in mice. Diabetologia 2022; 65:984-996. [PMID: 35316840 PMCID: PMC9076738 DOI: 10.1007/s00125-022-05669-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 12/13/2021] [Indexed: 01/01/2023]
Abstract
AIMS/HYPOTHESIS Pancreatic beta cell dedifferentiation, transdifferentiation into other islet cells and apoptosis have been implicated in beta cell failure in type 2 diabetes, although the mechanisms are poorly defined. The endoplasmic reticulum stress response factor X-box binding protein 1 (XBP1) is a major regulator of the unfolded protein response. XBP1 expression is reduced in islets of people with type 2 diabetes, but its role in adult differentiated beta cells is unclear. Here, we assessed the effects of Xbp1 deletion in adult beta cells and tested whether XBP1-mediated unfolded protein response makes a necessary contribution to beta cell compensation in insulin resistance states. METHODS Mice with inducible beta cell-specific Xbp1 deletion were studied under normal (chow diet) or metabolic stress (high-fat diet or obesity) conditions. Glucose tolerance, insulin secretion, islet gene expression, alpha cell mass, beta cell mass and apoptosis were assessed. Lineage tracing was used to determine beta cell fate. RESULTS Deletion of Xbp1 in adult mouse beta cells led to beta cell dedifferentiation, beta-to-alpha cell transdifferentiation and increased alpha cell mass. Cell lineage-specific analyses revealed that Xbp1 deletion deactivated beta cell identity genes (insulin, Pdx1, Nkx6.1, Beta2, Foxo1) and derepressed beta cell dedifferentiation (Aldh1a3) and alpha cell (glucagon, Arx, Irx2) genes. Xbp1 deletion in beta cells of obese ob/ob or high-fat diet-fed mice triggered diabetes and worsened glucose intolerance by disrupting insulin secretory capacity. Furthermore, Xbp1 deletion increased beta cell apoptosis under metabolic stress conditions by attenuating the antioxidant response. CONCLUSIONS/INTERPRETATION These findings indicate that XBP1 maintains beta cell identity, represses beta-to-alpha cell transdifferentiation and is required for beta cell compensation and prevention of diabetes in insulin resistance states.
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Affiliation(s)
- Kailun Lee
- Garvan Institute of Medical Research, St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Jeng Yie Chan
- Garvan Institute of Medical Research, St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Cassandra Liang
- Garvan Institute of Medical Research, St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Chi Kin Ip
- Garvan Institute of Medical Research, St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Yan-Chuan Shi
- Garvan Institute of Medical Research, St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Herbert Herzog
- Garvan Institute of Medical Research, St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, Australia
| | - William E Hughes
- Garvan Institute of Medical Research, St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, Australia
| | - Mohammed Bensellam
- Garvan Institute of Medical Research, St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, Australia
- Secteur des sciences de la santé, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Université catholique de Louvain, Brussels, Belgium
| | - Viviane Delghingaro-Augusto
- Medical School and John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
| | - Mark E Koina
- ACT Pathology, Canberra Health Services, Garran, ACT, Australia
| | - Christopher J Nolan
- Medical School and John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia
- Department of Endocrinology, The Canberra Hospital, Garran, ACT, Australia
| | - D Ross Laybutt
- Garvan Institute of Medical Research, St Vincent's Clinical School, UNSW Sydney, Darlinghurst, NSW, Australia.
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Chae CW, Choi GE, Jung YH, Lim JR, Cho JH, Yoon JH, Han HJ. High glucose-mediated VPS26a downregulation dysregulates neuronal amyloid precursor protein processing and tau phosphorylation. Br J Pharmacol 2022; 179:3934-3950. [PMID: 35297035 DOI: 10.1111/bph.15836] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 02/07/2022] [Accepted: 02/19/2022] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND AND PURPOSE The relationship between hyperglycaemia-induced retromer dysfunction impairing intracellular trafficking and AD remains unclear, although Diabetes mellitus (DM) is considered a risk factor for Alzheimer's disease (AD). Here, we investigated the effects of high glucose on the retromer, and defined the dysregulation of mechanisms of amyloid precursor protein (APP) processing and tau phosphorylation. EXPERIMENTAL APPROACH We used human induced-pluripotent stem cell-derived neuronal differentiated cells and SH-SY5Ys exposed to high glucose to identify the underlying mechanisms. Streptozotocin-induced diabetic mice were used to elucidate whether the retromer contributes to the AD-like pathology. KEY RESULTS We found that vacuolar protein sorting-associated protein 26a (VPS26a) was decreased in the hippocampus of diabetic mice and high glucose-treated human neuronal cells. High glucose downregulated VPS26a through ROS/NF-κB/DNA methyltransferase1-mediated promoter hypermethylation. VPS26a recovery blocked retention of APP and cation-independent mannose-6-phosphate receptor in endosomes and promoted transport to the trans-Golgi, which decreased Aβ levels, and improved Cathepsin D activity, reducing p-tau levels, respectively. Retromer enhancement ameliorated synaptic deficits, astrocyte over-activation, and cognitive impairment in diabetic mice. CONCLUSION AND IMPLICATIONS In conclusion, VPS26a is a promising candidate for the inhibition of DM-associated AD pathogenesis by modulating APP processing and tau phosphorylation.
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Affiliation(s)
- Chang Woo Chae
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, and BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University, Seoul, Republic of Korea
| | - Gee Euhn Choi
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, and BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University, Seoul, Republic of Korea
| | - Young Hyun Jung
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, and BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University, Seoul, Republic of Korea
| | - Jae Ryong Lim
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, and BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University, Seoul, Republic of Korea
| | - Ji Hyeon Cho
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, and BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University, Seoul, Republic of Korea
| | - Jee Hyeon Yoon
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, and BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University, Seoul, Republic of Korea
| | - Ho Jae Han
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science, and BK21 Four Future Veterinary Medicine Leading Education & Research Center, Seoul National University, Seoul, Republic of Korea
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Jouvet N, Bouyakdan K, Campbell SA, Baldwin C, Townsend SE, Gannon MA, Poitout V, Alquier T, Estall JL. The Tetracycline-Controlled Transactivator (Tet-On/Off) System in β-Cells Reduces Insulin Expression and Secretion in Mice. Diabetes 2021; 70:2850-2859. [PMID: 34610983 PMCID: PMC8660978 DOI: 10.2337/db21-0147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 09/29/2021] [Indexed: 11/13/2022]
Abstract
Controllable genetic manipulation is an indispensable tool in research, greatly advancing our understanding of cell biology and physiology. However in β-cells, transgene silencing, low inducibility, ectopic expression, and off-targets effects are persistent challenges. In this study, we investigated whether an inducible Tetracycline (Tet)-Off system with β-cell-specific mouse insulin promoter (MIP)-itTA-driven expression of tetracycline operon (TetO)-CreJaw/J could circumvent previous issues of specificity and efficacy. Following assessment of tissue-specific gene recombination, β-cell architecture, in vitro and in vivo glucose-stimulated insulin secretion, and whole-body glucose homeostasis, we discovered that expression of any tetracycline-controlled transactivator (e.g., improved itTA, reverse rtTA, or tTA) in β-cells significantly reduced Insulin gene expression and decreased insulin content. This translated into lower pancreatic insulin levels and reduced insulin secretion in mice carrying any tTA transgene, independent of Cre recombinase expression or doxycycline exposure. Our study echoes ongoing challenges faced by fundamental researchers working with β-cells and highlights the need for consistent and comprehensive controls when using the tetracycline-controlled transactivator systems (Tet-On or Tet-Off) for genome editing.
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Affiliation(s)
- Nathalie Jouvet
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
| | - Khalil Bouyakdan
- Montreal Diabetes Research Centre, Centre de recherche du centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
| | - Scott A Campbell
- Montreal Diabetes Research Centre, Centre de recherche du centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
- Département de Médecine, Université de Montréal, Montréal, Quebec, Canada
| | - Cindy Baldwin
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
| | - Shannon E Townsend
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Maureen A Gannon
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
- Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Vincent Poitout
- Montreal Diabetes Research Centre, Centre de recherche du centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
- Département de Médecine, Université de Montréal, Montréal, Quebec, Canada
| | - Thierry Alquier
- Montreal Diabetes Research Centre, Centre de recherche du centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
- Département de Médecine, Université de Montréal, Montréal, Quebec, Canada
| | - Jennifer L Estall
- Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
- Montreal Diabetes Research Centre, Centre de recherche du centre hospitalier de l'Université de Montréal (CRCHUM), Montréal, Quebec, Canada
- Département de Médecine, Université de Montréal, Montréal, Quebec, Canada
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11
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Cai Z, Liu F, Yang Y, Li D, Hu S, Song L, Yu S, Li T, Liu B, Luo H, Zhang W, Zhou Z, Zhang J. GRB10 regulates β cell mass by inhibiting β cell proliferation and stimulating β cell dedifferentiation. J Genet Genomics 2021; 49:208-216. [PMID: 34861413 DOI: 10.1016/j.jgg.2021.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 11/07/2021] [Accepted: 11/15/2021] [Indexed: 12/14/2022]
Abstract
Decreased functional β-cell mass is the hallmark of diabetes, but the cause of this metabolic defect remains elusive. Here, we show that the expression levels of the growth factor receptor-bound protein 10 (GRB10), a negative regulator of insulin and mTORC1 signaling, are markedly induced in islets of diabetic mice and high glucose-treated insulinoma cell line INS-1cells. β-cell-specific knockout of Grb10 in mice increased β-cell mass and improved β-cell function. Grb10-deficient β-cells exhibit enhanced mTORC1 signaling and reduced β-cell dedifferentiation, which could be blocked by rapamycin. On the contrary, Grb10 overexpression induced β-cell dedifferentiation in MIN6 cells. Our study identifies GRB10 as a critical regulator of β-cell dedifferentiation and β-cell mass, which exerts its effect by inhibiting mTORC1 signaling.
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Affiliation(s)
- Zixin Cai
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Fen Liu
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Yan Yang
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Dandan Li
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Shanbiao Hu
- Department of Urological Organ Transplantation, the Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Lei Song
- Department of Urological Organ Transplantation, the Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Shaojie Yu
- Department of Urological Organ Transplantation, the Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Ting Li
- Department of Liver Organ Transplantation, the Second Xiangya Hospital of Central South University, Changsha, Hunan 410011, China
| | - Bilian Liu
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Hairong Luo
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Weiping Zhang
- Department of Pathophysiology, Naval Medical University, Shanghai 200433, China
| | - Zhiguang Zhou
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Jingjing Zhang
- National Clinical Research Center for Metabolic Diseases, Metabolic Syndrome Research Center, Key Laboratory of Diabetes Immunology, Ministry of Education, and Department of Metabolism and Endocrinology, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China.
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12
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Martins R, Brito LF, Machado PC, Pinto LFB, Silva MR, Schenkel FS, Pedrosa VB. Genome-wide association study and pathway analysis for carcass fatness in Nellore cattle measured by ultrasound. Anim Genet 2021; 52:730-733. [PMID: 34370325 DOI: 10.1111/age.13129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2021] [Indexed: 12/16/2022]
Abstract
Identifying genes or genomic regions influencing carcass-quality traits such as fatness (FTN) is essential to optimize the genetic selection processes in beef cattle. The aim of this study was to identify genomic regions associated with FTN in Nellore cattle as well as to elucidate the metabolic pathways related to the phenotypic expression. Ultrasound-based measurements of FTN were collected in 11 750 animals, with 39 903 animals in the pedigree file. Additionally, 1440 animals were genotyped using the GGP-indicus 35K SNP panel, which contained 33 623 SNPs after quality control. Twenty genes related to FTN were found on 11 chromosomes, explaining 12.96% of the total additive genetic variance. Gene ontology revealed seven genes: NR1L2, PKD2, GSK3β, EXT1, RAD51B, SORCS1 and DPH6, associated with important processes related to FTN. In addition, novel candidate genes (MAATS1, LYPD1, CDK5RAP2, RAD51B, c13H2Oorf96 and TRAPPC11) were detected and could provide further knowledge to uncover genetic regions associated to carcass fatness in beef cattle.
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Affiliation(s)
- R Martins
- Department of Animal Sciences, State University of Ponta Grossa, Ponta Grossa, PR, 84030-900, Brazil
| | - L F Brito
- Department of Animal Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - P C Machado
- Department of Animal Sciences, State University of Ponta Grossa, Ponta Grossa, PR, 84030-900, Brazil
| | - L F B Pinto
- Department of Animal Sciences, Federal University of Bahia, Av. Adhemar de Barros s/n, Ondina, Salvador, BA, 40170-115, Brazil
| | - M R Silva
- Melhore Animal and Katayama Agropecuaria Lda, Guarapes, SP, 16700-000, Brazil
| | - F S Schenkel
- Animal and Poultry Science Department, Centre for Genetic Improvement of Livestock, University of Guelph, 50 Stone Road East, Guelph, ON, Canada
| | - V B Pedrosa
- Department of Animal Sciences, State University of Ponta Grossa, Ponta Grossa, PR, 84030-900, Brazil
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13
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Isolation and Proteomics of the Insulin Secretory Granule. Metabolites 2021; 11:metabo11050288. [PMID: 33946444 PMCID: PMC8147143 DOI: 10.3390/metabo11050288] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 04/28/2021] [Accepted: 04/28/2021] [Indexed: 12/21/2022] Open
Abstract
Insulin, a vital hormone for glucose homeostasis is produced by pancreatic beta-cells and when secreted, stimulates the uptake and storage of glucose from the blood. In the pancreas, insulin is stored in vesicles termed insulin secretory granules (ISGs). In Type 2 diabetes (T2D), defects in insulin action results in peripheral insulin resistance and beta-cell compensation, ultimately leading to dysfunctional ISG production and secretion. ISGs are functionally dynamic and many proteins present either on the membrane or in the lumen of the ISG may modulate and affect different stages of ISG trafficking and secretion. Previously, studies have identified few ISG proteins and more recently, proteomics analyses of purified ISGs have uncovered potential novel ISG proteins. This review summarizes the proteins identified in the current ISG proteomes from rat insulinoma INS-1 and INS-1E cell lines. Here, we also discuss techniques of ISG isolation and purification, its challenges and potential future directions.
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14
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Tokuo H, Komaba S, Coluccio LM. In pancreatic β-cells myosin 1b regulates glucose-stimulated insulin secretion by modulating an early step in insulin granule trafficking from the Golgi. Mol Biol Cell 2021; 32:1210-1220. [PMID: 33826361 PMCID: PMC8351557 DOI: 10.1091/mbc.e21-03-0094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Pancreatic β-cells secrete insulin, which controls blood glucose levels, and defects in insulin secretion are responsible for diabetes mellitus. The actin cytoskeleton and some myosins support insulin granule trafficking and release, although a role for the class I myosin Myo1b, an actin- and membrane-associated load-sensitive motor, in insulin biology is unknown. We found by immunohistochemistry that Myo1b is expressed in islet cells of the rat pancreas. In cultured rat insulinoma 832/13 cells, Myo1b localized near actin patches, the trans-Golgi network (TGN) marker TGN38, and insulin granules in the perinuclear region. Myo1b depletion by small interfering RNA in 832/13 cells reduced intracellular proinsulin and insulin content and glucose-stimulated insulin secretion (GSIS) and led to the accumulation of (pro)insulin secretory granules (SGs) at the TGN. Using an in situ fluorescent pulse-chase strategy to track nascent proinsulin, Myo1b depletion in insulinoma cells reduced the number of (pro)insulin-containing SGs budding from the TGN. The studies indicate for the first time that in pancreatic β-cells Myo1b controls GSIS at least in part by mediating an early stage in insulin granule trafficking from the TGN.
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Affiliation(s)
- Hiroshi Tokuo
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118-2518
| | - Shigeru Komaba
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118-2518
| | - Lynne M Coluccio
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118-2518
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15
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Liu M, Huang Y, Xu X, Li X, Alam M, Arunagiri A, Haataja L, Ding L, Wang S, Itkin-Ansari P, Kaufman RJ, Tsai B, Qi L, Arvan P. Normal and defective pathways in biogenesis and maintenance of the insulin storage pool. J Clin Invest 2021; 131:142240. [PMID: 33463547 PMCID: PMC7810482 DOI: 10.1172/jci142240] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Both basal and glucose-stimulated insulin release occur primarily by insulin secretory granule exocytosis from pancreatic β cells, and both are needed to maintain normoglycemia. Loss of insulin-secreting β cells, accompanied by abnormal glucose tolerance, may involve simple exhaustion of insulin reserves (which, by immunostaining, appears as a loss of β cell identity), or β cell dedifferentiation, or β cell death. While various sensing and signaling defects can result in diminished insulin secretion, somewhat less attention has been paid to diabetes risk caused by insufficiency in the biosynthetic generation and maintenance of the total insulin granule storage pool. This Review offers an overview of insulin biosynthesis, beginning with the preproinsulin mRNA (translation and translocation into the ER), proinsulin folding and export from the ER, and delivery via the Golgi complex to secretory granules for conversion to insulin and ultimate hormone storage. All of these steps are needed for generation and maintenance of the total insulin granule pool, and defects in any of these steps may, weakly or strongly, perturb glycemic control. The foregoing considerations have obvious potential relevance to the pathogenesis of type 2 diabetes and some forms of monogenic diabetes; conceivably, several of these concepts might also have implications for β cell failure in type 1 diabetes.
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Affiliation(s)
- Ming Liu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Yumeng Huang
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Xiaoxi Xu
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Xin Li
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Maroof Alam
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Anoop Arunagiri
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Leena Haataja
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Li Ding
- Department of Endocrinology and Metabolism, Tianjin Medical University General Hospital, Tianjin, China
| | - Shusen Wang
- Organ Transplant Center, Tianjin First Central Hospital, Tianjin, China
| | | | - Randal J. Kaufman
- Degenerative Diseases Program, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, California, USA
| | - Billy Tsai
- Department of Cell and Developmental Biology, and
| | - Ling Qi
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Peter Arvan
- Division of Metabolism, Endocrinology and Diabetes, University of Michigan Medical School, Ann Arbor, Michigan, USA
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16
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Martins R, Machado PC, Pinto LFB, Silva MR, Schenkel FS, Brito LF, Pedrosa VB. Genome-wide association study and pathway analysis for fat deposition traits in nellore cattle raised in pasture-based systems. J Anim Breed Genet 2020; 138:360-378. [PMID: 33232564 DOI: 10.1111/jbg.12525] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/30/2020] [Accepted: 11/01/2020] [Indexed: 02/06/2023]
Abstract
Genome-wide association study (GWAS) is a powerful tool to identify candidate genes and genomic regions underlying key biological mechanisms associated with economically important traits. In this context, the aim of this study was to identify genomic regions and metabolic pathways associated with backfat thickness (BFT) and rump fat thickness (RFT) in Nellore cattle, raised in pasture-based systems. Ultrasound-based measurements of BFT and RFT (adjusted to 18 months of age) were collected in 11,750 animals, with 39,903 animals in the pedigree file. Additionally, 1,440 animals were genotyped using the GGP-indicus 35K SNP chip, containing 33,623 SNPs after the quality control. The single-step GWAS analyses were performed using the BLUPF90 family programs. Candidate genes were identified through the Ensembl database incorporated in the BioMart tool, while PANTHER and REVIGO were used to identify the key metabolic pathways and gene networks. A total of 18 genomic regions located on 10 different chromosomes and harbouring 23 candidate genes were identified for BFT. For RFT, 22 genomic regions were found on 14 chromosomes, with a total of 29 candidate genes identified. The results of the pathway analyses showed important genes for BFT, including TBL1XR1, AHCYL2, SLC4A7, AADAT, VPS53, IDH2 and ETS1, which are involved in lipid metabolism, synthesis of cellular amino acids, transport of solutes, transport between Golgi Complex membranes, cell differentiation and cellular development. The main genes identified for RFT were GSK3β, LRP1B, EXT1, GRB2, SORCS1 and SLMAP, which are involved in metabolic pathways such as glycogen synthesis, lipid transport and homeostasis, polysaccharide and carbohydrate metabolism. Polymorphisms located in these candidate genes can be incorporated in commercial genotyping platforms to improve the accuracy of imputation and genomic evaluations for carcass fatness. In addition to uncovering biological mechanisms associated with carcass quality, the key gene pathways identified can also be incorporated in biology-driven genomic prediction methods.
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Affiliation(s)
- Rafaela Martins
- Department of Animal Sciences, State University of Ponta Grossa, Ponta Grossa, Brazil
| | - Pamela C Machado
- Department of Animal Sciences, State University of Ponta Grossa, Ponta Grossa, Brazil
| | | | - Marcio R Silva
- Melhore Animal and Katayama Agropecuaria Lda, Guararapes, Brazil
| | - Flavio S Schenkel
- Centre for Genetic Improvement of Livestock, Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - Luiz F Brito
- Department of Animal Sciences, Purdue University, West Lafayette, IN, USA
| | - Victor B Pedrosa
- Department of Animal Sciences, State University of Ponta Grossa, Ponta Grossa, Brazil
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17
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Yau B, Hays L, Liang C, Laybutt DR, Thomas HE, Gunton JE, Williams L, Hawthorne WJ, Thorn P, Rhodes CJ, Kebede MA. A fluorescent timer reporter enables sorting of insulin secretory granules by age. J Biol Chem 2020; 295:8901-8911. [PMID: 32341128 PMCID: PMC7335792 DOI: 10.1074/jbc.ra120.012432] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 03/21/2020] [Indexed: 01/03/2023] Open
Abstract
Within the pancreatic β-cells, insulin secretory granules (SGs) exist in functionally distinct pools, displaying variations in motility as well as docking and fusion capability. Current therapies that increase insulin secretion do not consider the existence of these distinct SG pools. Accordingly, these approaches are effective only for a short period, with a worsening of glycemia associated with continued decline in β-cell function. Insulin granule age is underappreciated as a determinant for why an insulin granule is selected for secretion and may explain why newly synthesized insulin is preferentially secreted from β-cells. Here, using a novel fluorescent timer protein, we aimed to investigate the preferential secretion model of insulin secretion and identify how granule aging is affected by variation in the β-cell environment, such as hyperglycemia. We demonstrate the use of a fluorescent timer construct, syncollin-dsRedE5TIMER, which changes its fluorescence from green to red over 18 h, in both microscopy and fluorescence-assisted organelle-sorting techniques. We confirm that the SG-targeting construct localizes to insulin granules in β-cells and does not interfere with normal insulin SG behavior. We visualize insulin SG aging behavior in MIN6 and INS1 β-cell lines and in primary C57BL/6J mouse and nondiabetic human islet cells. Finally, we separated young and old insulin SGs, revealing that preferential secretion of younger granules occurs in glucose-stimulated insulin secretion. We also show that SG population age is modulated by the β-cell environment in vivo in the db/db mouse islets and ex vivo in C57BL/6J islets exposed to different glucose environments.
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Affiliation(s)
- Belinda Yau
- Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia; School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia
| | - Lori Hays
- STEM-Department of Biology, Edmonds Community College, Lynnwood, Washington, USA
| | - Cassandra Liang
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia
| | - D Ross Laybutt
- Garvan Institute of Medical Research, Sydney, New South Wales, Australia; St. Vincent's Clinical School, University of New South Wales Sydney, Sydney, New South Wales, Australia
| | - Helen E Thomas
- St. Vincent's Institute, Fitzroy, Victoria, Australia; Department of Medicine, St. Vincent's Hospital, University of Melbourne, Fitzroy, Victoria, Australia
| | - Jenny E Gunton
- Faculty of Medicine and Health, the University of Sydney, Sydney, New South Wales, Australia; The Westmead Institute for Medical Research, University of Sydney, Westmead, New South Wales, Australia
| | - Lindy Williams
- Faculty of Medicine and Health, the University of Sydney, Sydney, New South Wales, Australia; National Pancreas and Islet Transplant Unit (NPITU), Westmead Hospital, Sydney, New South Wales, Australia
| | - Wayne J Hawthorne
- Faculty of Medicine and Health, the University of Sydney, Sydney, New South Wales, Australia; National Pancreas and Islet Transplant Unit (NPITU), Westmead Hospital, Sydney, New South Wales, Australia
| | - Peter Thorn
- Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia; Discipline of Physiology, School of Medical Sciences, Faculty of Medicine and Health, Charles Perkins Centre, University of Sydney, Camperdown, New South Wales, Australia
| | - Christopher J Rhodes
- Research and Early Development, Cardiovascular, Renal and Metabolic Diseases, BioPharmaceuticals R&D, AstraZeneca Ltd, Gaithersburg, Maryland, USA; Pacific Northwest Research Institute, Seattle, Washington, USA
| | - Melkam A Kebede
- Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia; School of Life and Environmental Sciences, Faculty of Science, University of Sydney, Sydney, New South Wales, Australia.
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18
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Su X, Peng D. New insight into sortilin in controlling lipid metabolism and the risk of atherogenesis. Biol Rev Camb Philos Soc 2020; 95:232-243. [PMID: 31625271 DOI: 10.1111/brv.12561] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 09/16/2019] [Accepted: 09/18/2019] [Indexed: 01/24/2023]
Affiliation(s)
- Xin Su
- Department of Cardiovascular Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
| | - Daoquan Peng
- Department of Cardiovascular Medicine, The Second Xiangya Hospital of Central South University, Changsha, Hunan, China
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19
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McGivney BA, Han H, Corduff LR, Katz LM, Tozaki T, MacHugh DE, Hill EW. Genomic inbreeding trends, influential sire lines and selection in the global Thoroughbred horse population. Sci Rep 2020; 10:466. [PMID: 31949252 PMCID: PMC6965197 DOI: 10.1038/s41598-019-57389-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023] Open
Abstract
The Thoroughbred horse is a highly valued domestic animal population under strong selection for athletic phenotypes. Here we present a high resolution genomics-based analysis of inbreeding in the population that may form the basis for evidence-based discussion amid concerns in the breeding industry over the increasing use of small numbers of popular sire lines, which may accelerate a loss of genetic diversity. In the most comprehensive globally representative sample of Thoroughbreds to-date (n = 10,118), including prominent stallions (n = 305) from the major bloodstock regions of the world, we show using pan-genomic SNP genotypes that there has been a highly significant decline in global genetic diversity during the last five decades (FIS R2 = 0.942, P = 2.19 × 10-13; FROH R2 = 0.88, P = 1.81 × 10-10) that has likely been influenced by the use of popular sire lines. Estimates of effective population size in the global and regional populations indicate that there is some level of regional variation that may be exploited to improve global genetic diversity. Inbreeding is often a consequence of selection, which in managed animal populations tends to be driven by preferences for cultural, aesthetic or economically advantageous phenotypes. Using a composite selection signals approach, we show that centuries of selection for favourable athletic traits among Thoroughbreds acts on genes with functions in behaviour, musculoskeletal conformation and metabolism. As well as classical selective sweeps at core loci, polygenic adaptation for functional modalities in cardiovascular signalling, organismal growth and development, cellular stress and injury, metabolic pathways and neurotransmitters and other nervous system signalling has shaped the Thoroughbred athletic phenotype. Our results demonstrate that genomics-based approaches to identify genetic outcrosses will add valuable objectivity to augment traditional methods of stallion selection and that genomics-based methods will be beneficial to actively monitor the population to address the marked inbreeding trend.
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Affiliation(s)
| | - Haige Han
- Plusvital Ltd, The Highline, Dun Laoghaire Business Park, Dublin, Ireland
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
| | - Leanne R Corduff
- Plusvital Ltd, The Highline, Dun Laoghaire Business Park, Dublin, Ireland
| | - Lisa M Katz
- UCD School of Veterinary Medicine, University College Dublin, Dublin, Ireland
| | - Teruaki Tozaki
- Genetic Analysis Department, Laboratory of Racing Chemistry, Utsunomiya, Tochigi, Japan
| | - David E MacHugh
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland
- UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin, Ireland
| | - Emmeline W Hill
- Plusvital Ltd, The Highline, Dun Laoghaire Business Park, Dublin, Ireland.
- UCD School of Agriculture and Food Science, University College Dublin, Dublin, Ireland.
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20
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Type 2 diabetes-associated single nucleotide polymorphism in Sorcs1 gene results in alternative processing of the Sorcs1 protein in INS1 β-cells. Sci Rep 2019; 9:19466. [PMID: 31857633 PMCID: PMC6923373 DOI: 10.1038/s41598-019-55873-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 12/03/2019] [Indexed: 01/20/2023] Open
Abstract
A threonine-to-Isoleucine (Thr52Ile) mutation within the pro-domain of the Sorcs1 gene was positionally cloned as the gene underlying a quantitative trait locus that affects fasting insulin levels in mice. In humans, genome-wide association studies and linkage studies have shown that SORCS1 is associated with diabetes and all of diabetes complications. We have recently shown that deletion of Sorcs1 in mice made obese with the leptinob mutation results in diabetes and an insulin granule stability defect. This present study investigates the functional consequence of the Sorcs1 Thr52Ile mutation in the rat INS1 β-cell line expressing either the wildtype or mutant Sorcs1 allele. We find that Sorcs1 Thr52Ile mutation is associated with increased basal insulin secretion, reduced glucose-stimulated insulin secretion and decreased insulin content in INS1 cells. Moreover, expression of Thr52Ile causes differential processing of the Sorcs1 protein resulting in the formation of an additional 90 kDa mutant form of the protein. The mutant form of the protein is localised to the ER, retains its pro-domain, and concurrently reduces expression of the functional mature 130 kDa Sorcs1 protein. These findings provide a mechanistic clue to why this specific allelic variation in Sorcs1 was associated with reduced insulin levels and type 2 diabetes.
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Ortega-Azorín C, Coltell O, Asensio EM, Sorlí JV, González JI, Portolés O, Saiz C, Estruch R, Ramírez-Sabio JB, Pérez-Fidalgo A, Ordovas JM, Corella D. Candidate Gene and Genome-Wide Association Studies for Circulating Leptin Levels Reveal Population and Sex-Specific Associations in High Cardiovascular Risk Mediterranean Subjects. Nutrients 2019; 11:nu11112751. [PMID: 31766143 PMCID: PMC6893551 DOI: 10.3390/nu11112751] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 11/04/2019] [Accepted: 11/09/2019] [Indexed: 12/13/2022] Open
Abstract
Leptin is a hormone crucial in the regulation of food intake and body-weight maintenance. However, the genes and gene variants that influence its plasma levels are still not well known. Results of studies investigating polymorphisms in candidate genes have been inconsistent, and, in addition, very few genome-wide association studies (GWAS) have been undertaken. Our aim was to investigate the genes and gene variants most associated with plasma leptin concentrations in a high-cardiovascular-risk Mediterranean population. We measured plasma leptin in 1011 men and women, and analyzed the genetic factors associated using three approaches: (1) Analyzing the single nucleotide polymorphisms (SNPs) reported in a GWAS meta-analysis in other populations (including an SNP in/near each of these LEP, SLC32A1, GCKR, CCNL, COBLL1, and FTO genes); (2) Investigating additional SNPs in/near those genes, also including the RLEP gene; and (3) Undertaking a GWAS to discover new genes. We did not find any statistically significant associations between the previously published SNPs and plasma leptin (Ln) in the whole population adjusting for sex and age. However, on undertaking an extensive screening of other gene variants in those genes to capture a more complete set of SNPs, we found more associations. Outstanding among the findings was the heterogeneity per sex. We detected several statistically significant interaction terms with sex for these SNPs in the candidate genes. The gene most associated with plasma leptin levels was the FTO gene in men (specifically the rs1075440 SNP) and the LEPR in women (specifically the rs12145690 SNP). In the GWAS on the whole population, we found several new associations at the p < 1 × 10-5 level, among them with the rs245908-CHN2 SNP (p = 1.6 × 10-6). We also detected a SNP*sex interaction at the GWAS significance level (p < 5 × 10-8), involving the SLIT3 gene, a gene regulated by estrogens. In conclusion, our study shows that the SNPs selected as relevant for plasma leptin levels in other populations, are not good markers for this Mediterranean population, so supporting those studies claiming a bias when generalizing GWAS results to different populations. These population-specific differences may include not only genetic characteristics, but also age, health status, and the influence of other environmental variables. In addition, we have detected several sex-specific effects. These results suggest that genomic analyses, involving leptin, should be estimated by sex and consider population-specificity for more precise estimations.
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Affiliation(s)
- Carolina Ortega-Azorín
- Department of Preventive Medicine and Public Health, School of Medicine, University of Valencia, 46010 Valencia, Spain; (C.O.-A.); (E.M.A.); (J.V.S.); (J.I.G.); (O.P.); (C.S.); (A.P.-F.)
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain; (O.C.); (R.E.)
| | - Oscar Coltell
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain; (O.C.); (R.E.)
- Department of Computer Languages and Systems, Universitat Jaume I, 12071 Castellón, Spain
| | - Eva M. Asensio
- Department of Preventive Medicine and Public Health, School of Medicine, University of Valencia, 46010 Valencia, Spain; (C.O.-A.); (E.M.A.); (J.V.S.); (J.I.G.); (O.P.); (C.S.); (A.P.-F.)
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain; (O.C.); (R.E.)
| | - Jose V. Sorlí
- Department of Preventive Medicine and Public Health, School of Medicine, University of Valencia, 46010 Valencia, Spain; (C.O.-A.); (E.M.A.); (J.V.S.); (J.I.G.); (O.P.); (C.S.); (A.P.-F.)
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain; (O.C.); (R.E.)
| | - José I. González
- Department of Preventive Medicine and Public Health, School of Medicine, University of Valencia, 46010 Valencia, Spain; (C.O.-A.); (E.M.A.); (J.V.S.); (J.I.G.); (O.P.); (C.S.); (A.P.-F.)
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain; (O.C.); (R.E.)
| | - Olga Portolés
- Department of Preventive Medicine and Public Health, School of Medicine, University of Valencia, 46010 Valencia, Spain; (C.O.-A.); (E.M.A.); (J.V.S.); (J.I.G.); (O.P.); (C.S.); (A.P.-F.)
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain; (O.C.); (R.E.)
| | - Carmen Saiz
- Department of Preventive Medicine and Public Health, School of Medicine, University of Valencia, 46010 Valencia, Spain; (C.O.-A.); (E.M.A.); (J.V.S.); (J.I.G.); (O.P.); (C.S.); (A.P.-F.)
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain; (O.C.); (R.E.)
| | - Ramon Estruch
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain; (O.C.); (R.E.)
- Department of Internal Medicine, Hospital Clinic, Institut d’Investigació Biomèdica August Pi i Sunyer (IDIBAPS), University of Barcelona, Villarroel, 170, 08036 Barcelona, Spain
| | | | - Alejandro Pérez-Fidalgo
- Department of Preventive Medicine and Public Health, School of Medicine, University of Valencia, 46010 Valencia, Spain; (C.O.-A.); (E.M.A.); (J.V.S.); (J.I.G.); (O.P.); (C.S.); (A.P.-F.)
- CIBER Cáncer, Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Jose M Ordovas
- Nutrition and Genomics Laboratory, JM-USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA;
- Department of Cardiovascular Epidemiology and Population Genetics, Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain
- IMDEA Alimentación, 28049 Madrid, Spain
| | - Dolores Corella
- Department of Preventive Medicine and Public Health, School of Medicine, University of Valencia, 46010 Valencia, Spain; (C.O.-A.); (E.M.A.); (J.V.S.); (J.I.G.); (O.P.); (C.S.); (A.P.-F.)
- CIBER Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, 28029 Madrid, Spain; (O.C.); (R.E.)
- Correspondence: ; Tel.: +34-96-386-4800
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Chaves G, Stanley J, Pourmand N. Mutant Huntingtin Affects Diabetes and Alzheimer's Markers in Human and Cell Models of Huntington's Disease. Cells 2019; 8:E962. [PMID: 31450785 PMCID: PMC6769852 DOI: 10.3390/cells8090962] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/14/2019] [Accepted: 08/21/2019] [Indexed: 02/07/2023] Open
Abstract
A higher incidence of diabetes was observed among family members of individuals affected by Huntington's Disease with no follow-up studies investigating the genetic nature of the observation. Using a genome-wide association study (GWAS), RNA sequencing (RNA-Seq) analysis and western blotting of Rattus norvegicus and human, we were able to identify that the gene family of sortilin receptors was affected in Huntington's Disease patients. We observed that less than 5% of SNPs were of statistical significance and that sortilins and HLA/MHC gene expression or SNPs were associated with mutant huntingtin (mHTT). These results suggest that ST14A cells derived from R. norvegicus are a reliable model of HD, since sortilins were identified through analysis of the transcriptome in these cells. These findings help highlight the genes involved in mechanisms targeted by diabetes drugs, such as glucose transporters as well as proteins controlling insulin release related to mHTT. To the best of our knowledge, this is the first GWAS using RNA-Seq data from both ST14A rat HD cell model and human Huntington's Disease.
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Affiliation(s)
- Gepoliano Chaves
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA
| | - John Stanley
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Nader Pourmand
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA.
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23
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Lysosomal degradation of newly formed insulin granules contributes to β cell failure in diabetes. Nat Commun 2019; 10:3312. [PMID: 31346174 PMCID: PMC6658524 DOI: 10.1038/s41467-019-11170-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 06/27/2019] [Indexed: 02/06/2023] Open
Abstract
Compromised function of insulin-secreting pancreatic β cells is central to the development and progression of Type 2 Diabetes (T2D). However, the mechanisms underlying β cell failure remain incompletely understood. Here, we report that metabolic stress markedly enhances macroautophagy-independent lysosomal degradation of nascent insulin granules. In different model systems of diabetes including of human origin, stress-induced nascent granule degradation (SINGD) contributes to loss of insulin along with mammalian/mechanistic Target of Rapamycin (mTOR)-dependent suppression of macroautophagy. Expression of Protein Kinase D (PKD), a negative regulator of SINGD, is reduced in diabetic β cells. Pharmacological activation of PKD counters SINGD and delays the onset of T2D. Conversely, inhibition of PKD exacerbates SINGD, mitigates insulin secretion and accelerates diabetes. Finally, reduced levels of lysosomal tetraspanin CD63 prevent SINGD, leading to increased insulin secretion. Overall, our findings implicate aberrant SINGD in the pathogenesis of diabetes and suggest new therapeutic strategies to prevent β cell failure. Impaired beta-cell insulin secretion is a key pathological feature of type 2 diabetes. Here, the authors describe metabolic stress induced lysosomal degradation of newly formed insulin granules, independent of macroautophagy, as a potential mechanism for beta-cell dysfunction.
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24
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Gloaguen E, Bendelac N, Nicolino M, Julier C, Mathieu F. A systematic review of non-genetic predictors and genetic factors of glycated haemoglobin in type 1 diabetes one year after diagnosis. Diabetes Metab Res Rev 2018; 34:e3051. [PMID: 30063815 DOI: 10.1002/dmrr.3051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 07/20/2018] [Accepted: 07/23/2018] [Indexed: 12/13/2022]
Abstract
Type 1 diabetes (T1D) results from autoimmune destruction of the pancreatic βcells. Although all T1D patients require daily administration of exogenous insulin, their insulin requirement to achieve good glycaemic control may vary significantly. Glycated haemoglobin (HbA1c) level represents a stable indicator of glycaemic control and is a reliable predictor of long-term complications of T1D. The purpose of this article is to systematically review the role of non-genetic predictors and genetic factors of HbA1c level in T1D patients after the first year of T1D, to exclude the honeymoon period. A total of 1974 articles published since January 2011 were identified and 78 were finally included in the analysis of non-genetic predictors. For genetic factors, a total of 277 articles were identified and 14 were included. The most significantly associated factors with HbA1c level are demographic (age, ethnicity, and socioeconomic status), personal (family characteristics, parental care, psychological traits...) and features related to T1D (duration of T1D, adherence to treatment …). Only a few studies have searched for genetic factors influencing HbA1c level, most of which focused on candidate genes using classical genetic statistical methods, with generally limited power and incomplete adjustment for confounding factors and multiple testing. Our review shows the complexity of explaining HbA1c level variations, which involves numerous correlated predictors. Overall, our review underlines the lack of studies investigating jointly genetic and non-genetic factors and their interactions to better understand factors influencing glycaemic control for T1D patients.
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Affiliation(s)
- Emilie Gloaguen
- Inserm UMRS-958, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | | | - Marc Nicolino
- Hôpital Femme-Mère-Enfant, Hospices Civils de Lyon, Bron, France
| | - Cécile Julier
- Inserm UMRS-958, Paris, France
- Université Paris Diderot, Sorbonne Paris Cité, Paris, France
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25
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Akhaphong B, Lockridge A, Jo S, Mohan R, Wilcox JA, Wing CR, Regal JF, Alejandro EU. Reduced uterine perfusion pressure causes loss of pancreatic β-cell area but normal function in fetal rat offspring. Am J Physiol Regul Integr Comp Physiol 2018; 315:R1220-R1231. [PMID: 30303709 DOI: 10.1152/ajpregu.00458.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Maternal hypertension during pregnancy is a major risk factor for intrauterine growth restriction (IUGR), which increases susceptibility to cardiovascular and metabolic disease in adulthood through unclear mechanisms. The aim of this study was to characterize the pancreatic β-cell area and function in the fetal rat offspring of a reduced uterine perfusion pressure (RUPP) model of gestational hypertension. At embryonic day 19.5, RUPP dams exhibited lower body weight, elevated mean blood pressure, reduced litter size, and higher blood glucose compared with sham-operated controls. In RUPP placental lysates, a nonsignificant change in mammalian target of rapamycin (mTOR) activity markers, phosphorylated S6 at serine 240, and phosphorylated AKT (at S473) was observed. RUPP offspring showed significantly reduced β-cell-to-pancreas area and increased β-cell death but normal insulin levels in serum. Isolated islets had normal insulin content and secretory function in response to glucose and palmitate. Fetal pancreatic lysates showed a tendency for reduced insulin levels, with a significant reduction in total mTOR protein with RUPP surgery. In addition, its downstream complex 2 targets phosphorylation of AKT at S473, and pAKT at Thr308 tended to be reduced in the fetal RUPP pancreas. Altogether, these data show that RUPP offspring demonstrated increased β-cell death, reduced β-cell area, and altered nutrient-sensor mTOR protein level in the pancreas. This could represent a mechanistic foundation in IUGR offspring's risk for enhanced susceptibility to type 2 diabetes and other metabolic vulnerabilities seen in adulthood.
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Affiliation(s)
- Brian Akhaphong
- Department of Integrative Biology & Physiology, University of Minnesota: Twin Cities, Minnesota
| | - Amber Lockridge
- Department of Integrative Biology & Physiology, University of Minnesota: Twin Cities, Minnesota
| | - Seokwon Jo
- Department of Integrative Biology & Physiology, University of Minnesota: Twin Cities, Minnesota
| | - Ramkumar Mohan
- Department of Integrative Biology & Physiology, University of Minnesota: Twin Cities, Minnesota
| | - Jacob A Wilcox
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, Minnesota
| | - Cameron R Wing
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, Minnesota
| | - Jean F Regal
- Department of Biomedical Sciences, University of Minnesota Medical School, Duluth Campus, Duluth, Minnesota
| | - Emilyn U Alejandro
- Department of Integrative Biology & Physiology, University of Minnesota: Twin Cities, Minnesota
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26
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Emperador-Melero J, Huson V, van Weering J, Bollmann C, Fischer von Mollard G, Toonen RF, Verhage M. Vti1a/b regulate synaptic vesicle and dense core vesicle secretion via protein sorting at the Golgi. Nat Commun 2018; 9:3421. [PMID: 30143604 PMCID: PMC6109172 DOI: 10.1038/s41467-018-05699-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 07/19/2018] [Indexed: 12/27/2022] Open
Abstract
The SNAREs Vti1a/1b are implicated in regulated secretion, but their role relative to canonical exocytic SNAREs remains elusive. Here, we show that synaptic vesicle and dense-core vesicle (DCV) secretion is indeed severely impaired in Vti1a/b-deficient neurons. The synaptic levels of proteins that mediate secretion were reduced, down to 50% for the exocytic SNARE SNAP25. The delivery of SNAP25 and DCV-cargo into axons was decreased and these molecules accumulated in the Golgi. These defects were rescued by either Vti1a or Vti1b expression. Distended Golgi cisternae and clear vacuoles were observed in Vti1a/b-deficient neurons. The normal non-homogeneous distribution of DCV-cargo inside the Golgi was lost. Cargo trafficking out of, but not into the Golgi, was impaired. Finally, retrograde Cholera Toxin trafficking, but not Sortilin/Sorcs1 distribution, was compromised. We conclude that Vti1a/b support regulated secretion by sorting secretory cargo and synaptic secretion machinery components at the Golgi.
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Affiliation(s)
- Javier Emperador-Melero
- Departments of Functional Genomics, Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands
| | - Vincent Huson
- Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands
| | - Jan van Weering
- Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands
| | - Christian Bollmann
- Department of Biochemistry III, Bielefeld University, 33615, Bielefeld, Germany
| | | | - Ruud F Toonen
- Departments of Functional Genomics, Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands
| | - Matthijs Verhage
- Departments of Functional Genomics, Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands. .,Clinical Genetics, VUmc, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, VU University Amsterdam and VU Medical Center, de Boelelaan 1087, 1081 HV, Amsterdam, The Netherlands.
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27
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Tokarz VL, MacDonald PE, Klip A. The cell biology of systemic insulin function. J Cell Biol 2018; 217:2273-2289. [PMID: 29622564 PMCID: PMC6028526 DOI: 10.1083/jcb.201802095] [Citation(s) in RCA: 224] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/21/2018] [Accepted: 03/23/2018] [Indexed: 12/12/2022] Open
Abstract
Tokarz et al. review the cell biology of insulin physiology throughout the body, from synthesis to the delivery, action, and final degradation of insulin. Insulin is the paramount anabolic hormone, promoting carbon energy deposition in the body. Its synthesis, quality control, delivery, and action are exquisitely regulated by highly orchestrated intracellular mechanisms in different organs or “stations” of its bodily journey. In this Beyond the Cell review, we focus on these five stages of the journey of insulin through the body and the captivating cell biology that underlies the interaction of insulin with each organ. We first analyze insulin’s biosynthesis in and export from the β-cells of the pancreas. Next, we focus on its first pass and partial clearance in the liver with its temporality and periodicity linked to secretion. Continuing the journey, we briefly describe insulin’s action on the blood vasculature and its still-debated mechanisms of exit from the capillary beds. Once in the parenchymal interstitium of muscle and adipose tissue, insulin promotes glucose uptake into myofibers and adipocytes, and we elaborate on the intricate signaling and vesicle traffic mechanisms that underlie this fundamental function. Finally, we touch upon the renal degradation of insulin to end its action. Cellular discernment of insulin’s availability and action should prove critical to understanding its pivotal physiological functions and how their failure leads to diabetes.
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Affiliation(s)
- Victoria L Tokarz
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Patrick E MacDonald
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada .,Department of Physiology, University of Toronto, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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28
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Burchfield JG, Kebede MA, Meoli CC, Stöckli J, Whitworth PT, Wright AL, Hoffman NJ, Minard AY, Ma X, Krycer JR, Nelson ME, Tan SX, Yau B, Thomas KC, Wee NKY, Khor EC, Enriquez RF, Vissel B, Biden TJ, Baldock PA, Hoehn KL, Cantley J, Cooney GJ, James DE, Fazakerley DJ. High dietary fat and sucrose results in an extensive and time-dependent deterioration in health of multiple physiological systems in mice. J Biol Chem 2018; 293:5731-5745. [PMID: 29440390 DOI: 10.1074/jbc.ra117.000808] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/12/2018] [Indexed: 01/17/2023] Open
Abstract
Obesity is associated with metabolic dysfunction, including insulin resistance and hyperinsulinemia, and with disorders such as cardiovascular disease, osteoporosis, and neurodegeneration. Typically, these pathologies are examined in discrete model systems and with limited temporal resolution, and whether these disorders co-occur is therefore unclear. To address this question, here we examined multiple physiological systems in male C57BL/6J mice following prolonged exposure to a high-fat/high-sucrose diet (HFHSD). HFHSD-fed mice rapidly exhibited metabolic alterations, including obesity, hyperleptinemia, physical inactivity, glucose intolerance, peripheral insulin resistance, fasting hyperglycemia, ectopic lipid deposition, and bone deterioration. Prolonged exposure to HFHSD resulted in morbid obesity, ectopic triglyceride deposition in liver and muscle, extensive bone loss, sarcopenia, hyperinsulinemia, and impaired short-term memory. Although many of these defects are typically associated with aging, HFHSD did not alter telomere length in white blood cells, indicating that this diet did not generally promote all aspects of aging. Strikingly, glucose homeostasis was highly dynamic. Glucose intolerance was evident in HFHSD-fed mice after 1 week and was maintained for 24 weeks. Beyond 24 weeks, however, glucose tolerance improved in HFHSD-fed mice, and by 60 weeks, it was indistinguishable from that of chow-fed mice. This improvement coincided with adaptive β-cell hyperplasia and hyperinsulinemia, without changes in insulin sensitivity in muscle or adipose tissue. Assessment of insulin secretion in isolated islets revealed that leptin, which inhibited insulin secretion in the chow-fed mice, potentiated glucose-stimulated insulin secretion in the HFHSD-fed mice after 60 weeks. Overall, the excessive calorie intake was accompanied by deteriorating function of numerous physiological systems.
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Affiliation(s)
- James G Burchfield
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Melkam A Kebede
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Christopher C Meoli
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Jacqueline Stöckli
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - P Tess Whitworth
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Amanda L Wright
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Nolan J Hoffman
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Annabel Y Minard
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Xiuquan Ma
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - James R Krycer
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Marin E Nelson
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Shi-Xiong Tan
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Belinda Yau
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Kristen C Thomas
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Natalie K Y Wee
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Ee-Cheng Khor
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Ronaldo F Enriquez
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Bryce Vissel
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Trevor J Biden
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Paul A Baldock
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Kyle L Hoehn
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - James Cantley
- Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
| | - Gregory J Cooney
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Charles Perkins Centre, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - David E James
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia, .,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and.,Charles Perkins Centre, Sydney Medical School, University of Sydney, Camperdown, New South Wales 2006, Australia
| | - Daniel J Fazakerley
- From the Charles Perkins Centre, School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales 2006, Australia.,Garvan Institute of Medical Research, Darlinghurst, Sydney, New South Wales 2010, Australia, and
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Subkhangulova A, Malik AR, Hermey G, Popp O, Dittmar G, Rathjen T, Poy MN, Stumpf A, Beed PS, Schmitz D, Breiderhoff T, Willnow TE. SORCS1 and SORCS3 control energy balance and orexigenic peptide production. EMBO Rep 2018; 19:embr.201744810. [PMID: 29440124 PMCID: PMC5891432 DOI: 10.15252/embr.201744810] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 01/15/2018] [Accepted: 01/22/2018] [Indexed: 12/20/2022] Open
Abstract
SORCS1 and SORCS3 are two related sorting receptors expressed in neurons of the arcuate nucleus of the hypothalamus. Using mouse models with individual or dual receptor deficiencies, we document a previously unknown function of these receptors in central control of metabolism. Specifically, SORCS1 and SORCS3 act as intracellular trafficking receptors for tropomyosin-related kinase B to attenuate signaling by brain-derived neurotrophic factor, a potent regulator of energy homeostasis. Loss of the joint action of SORCS1 and SORCS3 in mutant mice results in excessive production of the orexigenic neuropeptide agouti-related peptide and in a state of chronic energy excess characterized by enhanced food intake, decreased locomotor activity, diminished usage of lipids as metabolic fuel, and increased adiposity, albeit at overall reduced body weight. Our findings highlight a novel concept in regulation of the melanocortin system and the role played by trafficking receptors SORCS1 and SORCS3 in this process.
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Affiliation(s)
| | - Anna R Malik
- Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
| | - Guido Hermey
- Institute for Molecular and Cellular Cognition, Center for Molecular Neurobiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Oliver Popp
- Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
| | - Gunnar Dittmar
- Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany.,Berlin Institute of Health, Berlin, Germany
| | - Thomas Rathjen
- Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
| | - Matthew N Poy
- Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany
| | - Alexander Stumpf
- Neuroscience Research Center, Charité - University Medicine, Berlin, Germany
| | - Prateep Sanker Beed
- Neuroscience Research Center, Charité - University Medicine, Berlin, Germany
| | - Dietmar Schmitz
- Neuroscience Research Center, Charité - University Medicine, Berlin, Germany
| | | | - Thomas E Willnow
- Max-Delbrueck-Center for Molecular Medicine, Berlin, Germany .,Berlin Institute of Health, Berlin, Germany
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30
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Cattin-Ortolá J, Topalidou I, Dosey A, Merz AJ, Ailion M. The dense-core vesicle maturation protein CCCP-1 binds RAB-2 and membranes through its C-terminal domain. Traffic 2017; 18:720-732. [PMID: 28755404 DOI: 10.1111/tra.12507] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/26/2017] [Accepted: 07/26/2017] [Indexed: 12/18/2022]
Abstract
Dense-core vesicles (DCVs) are secretory organelles that store and release modulatory neurotransmitters from neurons and endocrine cells. Recently, the conserved coiled-coil protein CCCP-1 was identified as a component of the DCV biogenesis pathway in the nematode Caenorhabditis elegans. CCCP-1 binds the small GTPase RAB-2 and colocalizes with it at the trans-Golgi. Here, we report a structure-function analysis of CCCP-1 to identify domains of the protein important for its localization, binding to RAB-2, and function in DCV biogenesis. We find that the CCCP-1 C-terminal domain (CC3) has multiple activities. CC3 is necessary and sufficient for CCCP-1 localization and for binding to RAB-2, and is required for the function of CCCP-1 in DCV biogenesis. In addition, CCCP-1 binds membranes directly through its CC3 domain, indicating that CC3 may comprise a previously uncharacterized lipid-binding motif. We conclude that CCCP-1 is a coiled-coil protein that binds an activated Rab and localizes to the Golgi via its C-terminus, properties similar to members of the golgin family of proteins. CCCP-1 also shares biophysical features with golgins; it has an elongated shape and forms oligomers.
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Affiliation(s)
| | - Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington
| | - Annie Dosey
- Department of Biochemistry, University of Washington, Seattle, Washington
| | - Alexey J Merz
- Department of Biochemistry, University of Washington, Seattle, Washington.,Department of Physiology and Biophysics, University of Washington, Seattle, Washington
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington
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31
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Boland BB, Rhodes CJ, Grimsby JS. The dynamic plasticity of insulin production in β-cells. Mol Metab 2017; 6:958-973. [PMID: 28951821 PMCID: PMC5605729 DOI: 10.1016/j.molmet.2017.04.010] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Although the insulin-producing pancreatic β-cells are quite capable of adapting to both acute and chronic changes in metabolic demand, persistently high demand for insulin will ultimately lead to their progressive dysfunction and eventual loss. Recent and historical studies highlight the importance of 'resting' the β-cell as a means of preserving functional β-cell mass. SCOPE OF REVIEW We provide experimental evidence to highlight the remarkable plasticity for insulin production and secretion by the pancreatic β-cell alongside some clinical evidence that supports leveraging this unique ability to preserve β-cell function. MAJOR CONCLUSIONS Treatment strategies for type 2 diabetes mellitus (T2DM) targeted towards reducing the systemic metabolic burden, rather than demanding greater insulin production from an already beleaguered β-cell, should be emphasized to maintain endogenous insulin secretory function and delay the progression of T2DM.
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Key Words
- ATF6, Activating Transcription Factor 6
- CHOP, CCAAT/Enhancer-Binding Homologous Protein
- EPAC, Exchange Factor Directly Activated by cAMP
- EROβ1, ER-resident oxidoreductase β1
- GIP, Gastric Inhibitory Polypeptide
- GLP-1, Glucagon-like Peptide 1
- GLUT2, Glucose Transporter 2
- GSIS, Glucose Stimulated Insulin Secretion
- IREα, Inositol Requiring Enzyme α
- Insulin production
- NEFA, Non-esterified Fatty Acid
- PERK, Protein Kinase RNA-like Endoplasmic Reticulum Kinase
- PKA, Protein Kinase A
- PKC, Protein Kinase C
- PLC, Phospholipase C
- ROS, Reactive Oxygen Species
- SNAP-25, Soluble NSF Attachment Protein 25
- SNARE, Soluble NSF Attachment Protein Receptor
- STZ, Streptozotocin
- T2DM
- T2DM, Type 2 Diabetes Mellitus
- TRP, Transient Receptor Potential
- VAMP-2, Vehicle Associated Membrane Protein 2
- VDCC, Voltage Dependent Calcium Channel
- mTORC1, Mammalian Target of Rapamycin 1
- nH, Hill coefficient
- β-cell rest
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Affiliation(s)
- Brandon B. Boland
- MedImmune, Cardiovascular and Metabolic Disease Research, 1 MedImmune Way, Gaithersburg, MD 20878, USA
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Chaves G, Özel RE, Rao NV, Hadiprodjo H, Costa YD, Tokuno Z, Pourmand N. Metabolic and transcriptomic analysis of Huntington's disease model reveal changes in intracellular glucose levels and related genes. Heliyon 2017; 3:e00381. [PMID: 28920088 PMCID: PMC5576993 DOI: 10.1016/j.heliyon.2017.e00381] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 07/02/2017] [Accepted: 08/04/2017] [Indexed: 11/19/2022] Open
Abstract
Huntington's Disease (HD) is a neurodegenerative disorder caused by an expansion in a CAG-tri-nucleotide repeat that introduces a poly-glutamine stretch into the huntingtin protein (mHTT). Mutant huntingtin (mHTT) has been associated with several phenotypes including mood disorders and depression. Additionally, HD patients are known to be more susceptible to type II diabetes mellitus (T2DM), and HD mice model develops diabetes. However, the mechanism and pathways that link Huntington's disease and diabetes have not been well established. Understanding the underlying mechanisms can reveal potential targets for drug development in HD. In this study, we investigated the transcriptome of mHTT cell populations alongside intracellular glucose measurements using a functionalized nanopipette. Several genes related to glucose uptake and glucose homeostasis are affected. We observed changes in intracellular glucose concentrations and identified altered transcript levels of certain genes including Sorcs1, Hh-II and Vldlr. Our data suggest that these can be used as markers for HD progression. Sorcs1 may not only have a role in glucose metabolism and trafficking but also in glutamatergic pathways affecting trafficking of synaptic components.
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Orentas RJ, Sindiri S, Duris C, Wen X, He J, Wei JS, Jarzembowski J, Khan J. Paired Expression Analysis of Tumor Cell Surface Antigens. Front Oncol 2017; 7:173. [PMID: 28871274 PMCID: PMC5566986 DOI: 10.3389/fonc.2017.00173] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/31/2017] [Indexed: 01/15/2023] Open
Abstract
Adoptive immunotherapy with antibody-based therapy or with T cells transduced to express chimeric antigen receptors (CARs) is useful to the extent that the cell surface membrane protein being targeted is not expressed on normal tissues. The most successful CAR-based (anti-CD19) or antibody-based therapy (anti-CD20) in hematologic malignancies has the side effect of eliminating the normal B cell compartment. Targeting solid tumors may not provide a similar expendable marker. Beyond antibody to Her2/NEU and EGFR, very few antibody-based and no CAR-based therapies have seen broad clinical application for solid tumors. To expand the way in which the surfaceome of solid tumors can be analyzed, we created an algorithm that defines the pairwise relative overexpression of surface antigens. This enables the development of specific immunotherapies that require the expression of two discrete antigens on the surface of the tumor target. This dyad analysis was facilitated by employing the Hotelling’s T-squared test (Hotelling–Lawley multivariate analysis of variance) for two independent variables in comparison to a third constant entity (i.e., gene expression levels in normal tissues). We also present a unique consensus scoring mechanism for identifying transcripts that encode cell surface proteins. The unique application of our bioinformatics processing pipeline and statistical tools allowed us to compare the expression of two membrane protein targets as a pair, and to propose a new strategy based on implementing immunotherapies that require both antigens to be expressed on the tumor cell surface to trigger therapeutic effector mechanisms. Specifically, we found that, for MYCN amplified neuroblastoma, pairwise expression of ACVR2B or anaplastic lymphoma kinase (ALK) with GFRA3, GFRA2, Cadherin 24, or with one another provided the strongest hits. For MYCN, non-amplified stage 4 neuroblastoma, neurotrophic tyrosine kinase 1, or ALK paired with GFRA2, GFRA3, SSK1, GPR173, or with one another provided the most promising paired-hits. We propose that targeting these markers together would increase the specificity and thereby the safety of CAR-based therapy for neuroblastoma.
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Affiliation(s)
- Rimas J Orentas
- Lentigen Technology, Inc., a Miltenyi Biotec Company, Gaithersburg, MD, United States
| | - Sivasish Sindiri
- Genetics Branch, National Cancer Institute, Center for Cancer Research, National Institutes of Health, Bethesda, MD, United States
| | - Christine Duris
- Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Xinyu Wen
- Genetics Branch, National Cancer Institute, Center for Cancer Research, National Institutes of Health, Bethesda, MD, United States
| | - Jianbin He
- Genetics Branch, National Cancer Institute, Center for Cancer Research, National Institutes of Health, Bethesda, MD, United States
| | - Jun S Wei
- Genetics Branch, National Cancer Institute, Center for Cancer Research, National Institutes of Health, Bethesda, MD, United States
| | - Jason Jarzembowski
- Department of Pathology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Javed Khan
- Genetics Branch, National Cancer Institute, Center for Cancer Research, National Institutes of Health, Bethesda, MD, United States
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Januliene D, Manavalan A, Ovesen PL, Pedersen KM, Thirup S, Nykjær A, Moeller A. Hidden Twins: SorCS Neuroreceptors Form Stable Dimers. J Mol Biol 2017; 429:2907-2917. [PMID: 28827148 DOI: 10.1016/j.jmb.2017.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/09/2017] [Accepted: 08/11/2017] [Indexed: 11/26/2022]
Abstract
SorCS1, SorCS2 and SorCS3 belong to the Vps10p-domain family of multiligand receptors. Genetic and functional studies have linked SorCS receptors to psychiatric disorders, Alzheimer's disease and type 2 diabetes, demonstrating critical roles in neuronal functionality and metabolic control. Surprisingly, their structural composition has so far not been studied. Here we have characterized SorCS1, SorCS2 and SorCS3 using biochemical methods and electron microscopy. We found that their purified extracellular domains co-exist in stable dimeric and monomeric populations. This was supported by co-immunoprecipitation experiments, where membrane-bound dimers were successfully pulled down from cell lysate. While dimers were virtually unbreakable, dimerization of the monomeric population was promoted through enzymatic deglycosylation. We conclude that post-translational modifications, specifically the degree and pattern of glycosylation, regulate the oligomeric state of the protein. Hence, cells may dictate ligand specificity by controlling the ratio between monomers and dimers and, therefore, regulate the multiple functions of SorCS receptors.
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Affiliation(s)
- Dovile Januliene
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany; DANDRITE, iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark
| | | | - Peter Lund Ovesen
- DANDRITE, Department of Biomedicine, Aarhus University, Ole Worms Allé 3, 8000 Aarhus C, Denmark
| | - Karen-Marie Pedersen
- DANDRITE, Department of Biomedicine, Aarhus University, Ole Worms Allé 3, 8000 Aarhus C, Denmark
| | - Søren Thirup
- MIND Centre, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000 Aarhus C, Denmark
| | - Anders Nykjær
- Mayo Clinic, 4500 San Pablo Rd S, Jacksonville, FL 32224, USA; DANDRITE, Department of Biomedicine, Aarhus University, Ole Worms Allé 3, 8000 Aarhus C, Denmark
| | - Arne Moeller
- Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue-Straße 3, 60438 Frankfurt am Main, Germany; DANDRITE, iNANO, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.
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Attie AD, Churchill GA, Nadeau JH. How mice are indispensable for understanding obesity and diabetes genetics. Curr Opin Endocrinol Diabetes Obes 2017; 24:83-91. [PMID: 28107248 PMCID: PMC5837807 DOI: 10.1097/med.0000000000000321] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
PURPOSE OF REVIEW The task of cataloging human genetic variation and its relation to disease is rapidly approaching completion. The new challenge is to discover the function of disease-associated genes and to understand the pathways that lead to human disease. We propose that achieving this new level of understanding will increasingly rely on the use of model organisms. We discuss the advantages of the mouse as a model organism to our understanding of human disease. RECENT FINDINGS The collection of available mouse strains represents as much genetic and phenotypic variation as is found in the human population. However, unlike humans, mice can be subjected to experimental breeding protocols and the availability of tissues allows for a far greater and deeper level of phenotyping. New methods for gene editing make it relatively easy to create mouse models of known human mutations. The distinction between genetic and epigenetic inheritance can be studied in great detail. Various experimental protocols enable the exploration of the role of the microbiome in physiology and disease. SUMMARY We propose that there will be an interdependence between human and model organism research. Technological advances and new genetic screening platforms in the mouse have greatly improved the path to gene discovery and mechanistic studies of gene function.
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Affiliation(s)
- Alan D Attie
- aDepartment of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin bThe Jackson Laboratory, Bar Harbor, Maine cPacific Northwest Research Institute, Seattle, Washington, USA
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Topalidou I, Cattin-Ortolá J, Pappas AL, Cooper K, Merrihew GE, MacCoss MJ, Ailion M. The EARP Complex and Its Interactor EIPR-1 Are Required for Cargo Sorting to Dense-Core Vesicles. PLoS Genet 2016; 12:e1006074. [PMID: 27191843 PMCID: PMC4871572 DOI: 10.1371/journal.pgen.1006074] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 04/30/2016] [Indexed: 12/15/2022] Open
Abstract
The dense-core vesicle is a secretory organelle that mediates the regulated release of peptide hormones, growth factors, and biogenic amines. Dense-core vesicles originate from the trans-Golgi of neurons and neuroendocrine cells, but it is unclear how this specialized organelle is formed and acquires its specific cargos. To identify proteins that act in dense-core vesicle biogenesis, we performed a forward genetic screen in Caenorhabditis elegans for mutants defective in dense-core vesicle function. We previously reported the identification of two conserved proteins that interact with the small GTPase RAB-2 to control normal dense-core vesicle cargo-sorting. Here we identify several additional conserved factors important for dense-core vesicle cargo sorting: the WD40 domain protein EIPR-1 and the endosome-associated recycling protein (EARP) complex. By assaying behavior and the trafficking of dense-core vesicle cargos, we show that mutants that lack EIPR-1 or EARP have defects in dense-core vesicle cargo-sorting similar to those of mutants in the RAB-2 pathway. Genetic epistasis data indicate that RAB-2, EIPR-1 and EARP function in a common pathway. In addition, using a proteomic approach in rat insulinoma cells, we show that EIPR-1 physically interacts with the EARP complex. Our data suggest that EIPR-1 is a new interactor of the EARP complex and that dense-core vesicle cargo sorting depends on the EARP-dependent trafficking of cargo through an endosomal sorting compartment. Animal cells package and store many important signaling molecules in specialized compartments called dense-core vesicles. Molecules stored in dense-core vesicles include peptide hormones like insulin and small molecule neurotransmitters like dopamine. Defects in the release of these compounds can lead to a wide range of metabolic and mental disorders in humans, including diabetes, depression, and drug addiction. However, it is not well understood how dense-core vesicles are formed in cells and package the appropriate molecules. Here we use a genetic screen in the microscopic worm C. elegans to identify proteins that are important for early steps in the generation of dense-core vesicles, such as packaging the correct molecular cargos in the vesicles. We identify several factors that are conserved between worms and humans and point to a new role for a protein complex that had previously been shown to be important for controlling trafficking in other cellular compartments. The identification of this complex suggests new cellular trafficking events that may be important for the generation of dense-core vesicles.
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Affiliation(s)
- Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Jérôme Cattin-Ortolá
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Andrea L. Pappas
- Department of Neurobiology, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Kirsten Cooper
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Gennifer E. Merrihew
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Michael J. MacCoss
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Knight EM, Ruiz HH, Kim SH, Harte JC, Hsieh W, Glabe C, Klein WL, Attie AD, Buettner C, Ehrlich ME, Gandy S. Unexpected partial correction of metabolic and behavioral phenotypes of Alzheimer's APP/PSEN1 mice by gene targeting of diabetes/Alzheimer's-related Sorcs1. Acta Neuropathol Commun 2016; 4:16. [PMID: 26916443 PMCID: PMC4766719 DOI: 10.1186/s40478-016-0282-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/25/2016] [Indexed: 02/06/2023] Open
Abstract
Introduction Insulin resistance and type 2 diabetes mellitus (T2D) are associated with increased risk for cognitive impairment, Alzheimer’s disease (AD) and vascular dementia. SORCS1 encodes a protein-sorting molecule genetically linked to both T2D and AD. The association of SORCS1 with both AD and T2D is sexually dimorphic in humans, with both disease associations showing more robust effects in females. Based on published evidence that manipulation of the mouse genome combining multiple genes related to cerebral amyloidosis, to T2D, or both, might provide novel mouse models with exacerbated amyloid and/or diabetes phenotypes, we assessed memory, glucose homeostasis, and brain biochemistry and pathology in male and female wild-type, Sorcs1 -/-, APP/PSEN1, and Sorcs1 -/- X APP/PSEN1 mice. Results Male mice with either the APP/PSEN1 or Sorcs1 -/- genotype displayed earlier onset and persistent impairment in both learning behavior and glucose homeostasis. Unlike prior examples in the literature, the behavioral and metabolic abnormalities in male mice were not significantly exacerbated when the two disease model mice (Sorcs1 -/- models T2D; APP/PSEN1 models AD) were crossed. However, female Sorcs1 -/- X APP/PSEN1 mice exhibited worse metabolic dysfunction than Sorcs1 -/- knockout mice and worse memory than wild-type mice. The deletion of Sorcs1 from APP/PSEN1 mutant mice led to no obvious changes in brain levels of total or oligomeric amyloid-beta (Aβ) peptide. Conclusions In general, unexpectedly, there was a trend for gene targeting of Sorcs1-/- to partially mitigate, not exacerbate, the metabolic and amyloid pathologies. These results indicate that crossing AD model mice and T2D model mice may not always cause exacerbation of both the amyloidosis phenotype and the metabolic phenotype and highlight the unexpected pitfalls of creating mixed models of disease. Electronic supplementary material The online version of this article (doi:10.1186/s40478-016-0282-y) contains supplementary material, which is available to authorized users.
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Schmidt V, Willnow TE. Protein sorting gone wrong – VPS10P domain receptors in cardiovascular and metabolic diseases. Atherosclerosis 2016; 245:194-9. [DOI: 10.1016/j.atherosclerosis.2015.11.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/04/2015] [Accepted: 11/23/2015] [Indexed: 01/02/2023]
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Coulson EJ, Andersen OM. The A-B-C for SORting APP. J Neurochem 2016; 135:1-3. [PMID: 26414457 DOI: 10.1111/jnc.13231] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 06/30/2015] [Indexed: 11/30/2022]
Abstract
This Editorial highlights a study by Hermey and colleagues in the current issue of Journal of Neurochemistry. In their study, the authors provide novel insights into single-nucleotide polymorphisms associated with Alzheimer's disease and linked to the SorCS1 gene, toward a better understanding of the interaction of sorting receptor proteins which physically interact with the amyloid-beta protein precursor (APP). SorCS1, sortilin-related VPS10 domain-containing receptor 1; SorLA, sortilin-related Receptor with A-type Repeats. Read the full article 'SorCS1 variants and amyloid precursor protein (APP) are co-transported in neurons but only SorCS1c modulates anterograde APP transport' on page 60.
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Affiliation(s)
- Elizabeth J Coulson
- School of Biomedical Sciences, Queensland Brain Institute, Clem Jones Centre for Ageing Dementia Research, The University of Queensland, Brisbane, Queensland, Australia
| | - Olav M Andersen
- The Lundbeck Foundation Research Center MIND, Danish Research Institute of Translational Neuroscience (DANDRITE) Nordic EMBL Partnership, Department of Biomedicine, Aarhus University, Aarhus, Denmark
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Jiang S, Shen D, Jia WJ, Han X, Shen N, Tao W, Gao X, Xue B, Li CJ. GGPPS-mediated Rab27A geranylgeranylation regulates β cell dysfunction during type 2 diabetes development by affecting insulin granule docked pool formation. J Pathol 2015; 238:109-19. [PMID: 26434932 DOI: 10.1002/path.4652] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 08/19/2015] [Accepted: 09/28/2015] [Indexed: 11/09/2022]
Abstract
Loss of first-phase insulin secretion associated with β cell dysfunction is an independent predictor of type 2 diabetes mellitus (T2DM) onset. Here we found that a critical enzyme involved in protein prenylation, geranylgeranyl pyrophosphate synthase (GGPPS), is required to maintain first-phase insulin secretion. GGPPS shows a biphasic expression pattern in islets of db/db mice during the progression of T2DM: GGPPS is increased during the insulin compensatory period, followed by a decrease during β cell dysfunction. Ggpps deletion in β cells results in typical T2DM β cell dysfunction, with blunted glucose-stimulated insulin secretion and consequent insulin secretion insufficiency. However, the number and size of islets and insulin biosynthesis are unaltered. Transmission electron microscopy shows a reduced number of insulin granules adjacent to the cellular membrane, suggesting a defect in docked granule pool formation, while the reserve pool is unaffected. Ggpps ablation depletes GGPP and impairs Rab27A geranylgeranylation, which is responsible for the docked pool deficiency in Ggpps-null mice. Moreover, GGPPS re-expression or GGPP administration restore glucose-stimulated insulin secretion in Ggpps-null islets. These results suggest that GGPPS-controlled protein geranylgeranylation, which regulates formation of the insulin granule docked pool, is critical for β cell function and insulin release during the development of T2DM.
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Affiliation(s)
- Shan Jiang
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Centre and School of Medicine, Nanjing University, People's Republic of China
| | - Di Shen
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Centre and School of Medicine, Nanjing University, People's Republic of China
| | - Wen-Jun Jia
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Centre and School of Medicine, Nanjing University, People's Republic of China
| | - Xiao Han
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, People's Republic of China
| | - Ning Shen
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Centre and School of Medicine, Nanjing University, People's Republic of China
| | - Weiwei Tao
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Centre and School of Medicine, Nanjing University, People's Republic of China
| | - Xiang Gao
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Centre and School of Medicine, Nanjing University, People's Republic of China
| | - Bin Xue
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Centre and School of Medicine, Nanjing University, People's Republic of China
| | - Chao-Jun Li
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Centre and School of Medicine, Nanjing University, People's Republic of China
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Klinger SC, Siupka P, Nielsen MS. Retromer-Mediated Trafficking of Transmembrane Receptors and Transporters. MEMBRANES 2015; 5:288-306. [PMID: 26154780 PMCID: PMC4584283 DOI: 10.3390/membranes5030288] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 06/29/2015] [Indexed: 12/21/2022]
Abstract
Transport between the endoplasmatic reticulum, the Golgi-network, the endo-lysosomal system and the cell surface can be categorized as anterograde or retrograde, describing traffic that goes forward or backward, respectively. Traffic going from the plasma membrane to endosomes and lysosomes or the trans-Golgi network (TGN) constitutes the major retrograde transport routes. Several transmembrane proteins undergo retrograde transport as part of a recycling mechanism that contributes to reutilization and maintenance of a steady-state protein localization. In addition, some receptors are hijacked by exotoxins and used for entry and intracellular transport. The physiological relevance of retrograde transport cannot be overstated. Retrograde trafficking of the amyloid precursor protein determines the distribution between organelles, and hence the possibility of cleavage by γ-secretase. Right balancing of the pathways is critical for protection against Alzheimer’s disease. During embryonic development, retrograde transport of Wntless to the TGN is essential for the following release of Wnt from the plasma membrane. Furthermore, overexpression of Wntless has been linked to oncogenesis. Here, we review relevant aspects of the retrograde trafficking of mammalian transmembrane receptors and transporters, with focus on the retromer-mediated transport between endosomes and the TGN.
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Affiliation(s)
- Stine C Klinger
- The Lundbeck Foundation Initiative on Brain Barriers and Drug Delivery, Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
| | - Piotr Siupka
- The Lundbeck Foundation Initiative on Brain Barriers and Drug Delivery, Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
| | - Morten S Nielsen
- The Lundbeck Foundation Initiative on Brain Barriers and Drug Delivery, Department of Biomedicine, Aarhus University, 8000 Aarhus C, Denmark.
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Ackert-Bicknell CL, Anderson LC, Sheehan S, Hill WG, Chang B, Churchill GA, Chesler EJ, Korstanje R, Peters LL. Aging Research Using Mouse Models. ACTA ACUST UNITED AC 2015; 5:95-133. [PMID: 26069080 DOI: 10.1002/9780470942390.mo140195] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Despite the dramatic increase in human lifespan over the past century, there remains pronounced variability in "health-span," or the period of time in which one is generally healthy and free of disease. Much of the variability in health-span and lifespan is thought to be genetic in origin. Understanding the genetic mechanisms of aging and identifying ways to boost longevity is a primary goal in aging research. Here, we describe a pipeline of phenotypic assays for assessing mouse models of aging. This pipeline includes behavior/cognition testing, body composition analysis, and tests of kidney function, hematopoiesis, and immune function, as well as physical parameters. We also describe study design methods for assessing lifespan and health-span, and other important considerations when conducting aging research in the laboratory mouse. The tools and assays provided can assist researchers with understanding the correlative relationships between age-associated phenotypes and, ultimately, the role of specific genes in the aging process.
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Affiliation(s)
- Cheryl L Ackert-Bicknell
- The Jackson Laboratory, Bar Harbor, Maine.,Present address: University of Rochester, Department of Orthopaedics and Rehabilitation, Rochester, New York
| | | | | | - Warren G Hill
- Laboratory of Voiding Dysfunction, Department of Medicine, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine
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Brix K, McInnes J, Al-Hashimi A, Rehders M, Tamhane T, Haugen MH. Proteolysis mediated by cysteine cathepsins and legumain-recent advances and cell biological challenges. PROTOPLASMA 2015; 252:755-774. [PMID: 25398648 DOI: 10.1007/s00709-014-0730-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 11/04/2014] [Indexed: 06/04/2023]
Abstract
Proteases play essential roles in protein degradation, protein processing, and extracellular matrix remodeling in all cell types and tissues. They are also involved in protein turnover for maintenance of homeostasis and protein activation or inactivation for cell signaling. Proteases range in function and specificity, with some performing distinct substrate cleavages, while others accomplish proteolysis of a wide range of substrates. As such, different cell types use specialized molecular mechanisms to regulate the localization of proteases and their function within the compartments to which they are destined. Here, we focus on the cysteine family of cathepsin proteases and legumain, which act predominately within the endo-lysosomal pathway. In particular, recent knowledge on cysteine cathepsins and their primary regulator legumain is scrutinized in terms of their trafficking to endo-lysosomal compartments and other less recognized cellular locations. We further explore the mechanisms that regulate these processes and point to pathological cases which arise from detours taken by these proteases. Moreover, the emerging biological roles of specific forms and variants of cysteine cathepsins and legumain are discussed. These may be decisive, pathogenic, or even deadly when localizing to unusual cellular compartments in their enzymatically active form, because they may exert unexpected effects by alternative substrate cleavage. Hence, we propose future perspectives for addressing the actions of cysteine cathepsins and legumain as well as their specific forms and variants. The increasing knowledge in non-canonical aspects of cysteine cathepsin- and legumain-mediated proteolysis may prove valuable for developing new strategies to utilize these versatile proteases in therapeutic approaches.
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Affiliation(s)
- Klaudia Brix
- Research Area HEALTH, Research Center MOLIFE-Molecular Life Sciences, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany,
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