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Robino A, Tornese G, Tinti D, Dovc K, Castorani V, Conti A, Franceschi R, Rabbone I, Bonfanti R, Battelino T, Catamo E. Role of HNFA1 Gene Variants in Pancreatic Beta Cells Function and Glycaemic Control in Young Individuals with Type 1 Diabetes. Biomedicines 2023; 11:1951. [PMID: 37509590 PMCID: PMC10377126 DOI: 10.3390/biomedicines11071951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 06/30/2023] [Accepted: 07/05/2023] [Indexed: 07/30/2023] Open
Abstract
The HNF1A transcription factor, implicated in the regulation of pancreatic beta cells, as well as in glucose and lipid metabolism, is responsible for type 3 maturity-onset diabetes of the young (MODY3). HNF1A is also involved in increased susceptibility to polygenic forms of diabetes, such as type 2 diabetes (T2D) and gestational diabetes (GD), while its possible role in type 1 diabetes (T1D) is not known. In this study, 277 children and adolescents with T1D and 140 healthy controls were recruited. The following SNPs in HNF1A gene were selected: rs1169286, rs1169288, rs7979478, and rs2259816. Through linear or logistic regression analysis, we analyzed their association with T1D susceptibility and related clinical traits, such as insulin dose-adjusted glycated hemoglobin A1c (IDAA1c) and glycated hemoglobin (HbA1c). We found that rs1169286 was associated with IDAA1c and HbA1c values (p-value = 0.0027 and p-value = 0.0075, respectively), while rs1169288 was associated with IDAA1c (p-value = 0.0081). No association between HNF1A SNPs and T1D development emerged. In conclusion, our findings suggest for the first time that HNF1A variants may be a risk factor for beta cell function and glycaemic control in T1D individuals.
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Affiliation(s)
- Antonietta Robino
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, 34137 Trieste, Italy
| | - Gianluca Tornese
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, 34137 Trieste, Italy
| | - Davide Tinti
- Center for Pediatric Diabetology, A.O.U. Città della Salute e della Scienza, 10126 Torino, Italy
| | - Klemen Dovc
- Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
- Department of Endocrinology, Diabetes and Metabolism, University Children's Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
| | - Valeria Castorani
- Department of Pediatrics, IRCCS San Raffaele Hospital, Diabetes Research Institute, 20132 Milano, Italy
| | - Andrea Conti
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, 34137 Trieste, Italy
| | - Roberto Franceschi
- Division of Pediatrics, S. Chiara General Hospital, APSS, 38122 Trento, Italy
| | - Ivana Rabbone
- Division of Pediatrics, Department of Health Sciences, Università del Piemonte Orientale, 28100 Novara, Italy
| | - Riccardo Bonfanti
- Department of Pediatrics, IRCCS San Raffaele Hospital, Diabetes Research Institute, 20132 Milano, Italy
| | - Tadej Battelino
- Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
- Department of Endocrinology, Diabetes and Metabolism, University Children's Hospital, University Medical Centre Ljubljana, 1000 Ljubljana, Slovenia
| | - Eulalia Catamo
- Institute for Maternal and Child Health-IRCCS Burlo Garofolo, 34137 Trieste, Italy
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Grewal R, Choung HYG, Roberts LL, Beane T, Chen L, Gilroy DX, Rappold PM, Le TH. TMEM27 expression and clinical characteristics and survival in clear cell renal cell carcinoma. Acta Oncol 2022; 61:1507-1511. [PMID: 36369873 DOI: 10.1080/0284186x.2022.2143279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Transmembrane protein 27 (TMEM27/collectrin), a glycoprotein and homolog of angiotensin-converting enzyme 2 (ACE2), is a regulator of renal amino acid uptake in the proximal tubule and may have a protective role in hypertension. Two previous reports have shown that the absence of TMEM27 expression in clear cell renal cell carcinoma (ccRCC) correlates with poorer cancer-related survival. We report our findings of TMEM27 expression in ccRCC and clinical outcomes in an independent third cohort. MATERIAL AND METHODS We conducted a retrospective analysis to identify all 321 cases of ccRCC diagnosed between 2010 and 2015 at the University of Rochester Medical Center. The intensity of TMEM27 immunostaining on tumor tissue was semi-quantitatively graded on a scale of 0, 0.5, 1, 1.5, 2, 2.5, and 3 by a single pathologist, and correlated with tumor characteristics and survival. RESULTS There was evidence of metastasis at time of nephrectomy in 36 (11.2%) cases, and at the latest follow-up in 70 (21.8%) cases. As of Spring 2021, 82 (25.5%) had died. TMEM27 staining intensity correlated inversely with various tumor characteristics. Kaplan-Meier survival analysis showed worse overall all-cause mortality (p = 0.02) and disease-free survival (p = 0.028) for tumors without any TMEM27 staining (0) compared to 0.5 or higher by log-rank test. CONCLUSION The absence of TMEM27 expression is associated with more aggressive tumor characteristics and poorer all-cause mortality and disease-free survival in ccRCC. TMEM27 may be a useful biomarker to assess cancer prognosis. Further studies are needed to better assess if TMEM27 is protective in RCC, and its potential role in active surveillance and prediction of response to target therapy.
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Affiliation(s)
- Rickinder Grewal
- Division of Nephrology, Department of Medicine, University of Rochester, School of Medicine & Dentistry, Rochester, NY, USA
| | - Hae Yoon G Choung
- Division of Renal Pathology and Electron Microscopy, Department of Pathology and Laboratory Medicine, University of Rochester, School of Medicine & Dentistry, Rochester, NY, USA
| | - Lisa L Roberts
- Division of Nephrology, Department of Medicine, University of Rochester, School of Medicine & Dentistry, Rochester, NY, USA
| | - Timothy Beane
- Division of Nephrology, Department of Medicine, University of Rochester, School of Medicine & Dentistry, Rochester, NY, USA
| | - Luojing Chen
- Division of Nephrology, Department of Medicine, University of Rochester, School of Medicine & Dentistry, Rochester, NY, USA
| | | | - Phillip M Rappold
- Department of Urology, University of Rochester, School of Medicine & Dentistry, Rochester, NY, USA
| | - Thu H Le
- Division of Nephrology, Department of Medicine, University of Rochester, School of Medicine & Dentistry, Rochester, NY, USA
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3
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Li LM, Jiang BG, Sun LL. HNF1A:From Monogenic Diabetes to Type 2 Diabetes and Gestational Diabetes Mellitus. Front Endocrinol (Lausanne) 2022; 13:829565. [PMID: 35299962 PMCID: PMC8921476 DOI: 10.3389/fendo.2022.829565] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/03/2022] [Indexed: 12/12/2022] Open
Abstract
Diabetes, a disease characterized by hyperglycemia, has a serious impact on the lives and families of patients as well as on society. Diabetes is a group of highly heterogeneous metabolic diseases that can be classified as type 1 diabetes (T1D), type 2 diabetes (T2D), gestational diabetes mellitus (GDM), or other according to the etiology. The clinical manifestations are more or less similar among the different types of diabetes, and each type is highly heterogeneous due to different pathogenic factors. Therefore, distinguishing between various types of diabetes and defining their subtypes are major challenges hindering the precise treatment of the disease. T2D is the main type of diabetes in humans as well as the most heterogeneous. Fortunately, some studies have shown that variants of certain genes involved in monogenic diabetes also increase the risk of T2D. We hope this finding will enable breakthroughs regarding the pathogenesis of T2D and facilitate personalized treatment of the disease by exploring the function of the signal genes involved. Hepatocyte nuclear factor 1 homeobox A (HNF1α) is widely expressed in pancreatic β cells, the liver, the intestines, and other organs. HNF1α is highly polymorphic, but lacks a mutation hot spot. Mutations can be found at any site of the gene. Some single nucleotide polymorphisms (SNPs) cause maturity-onset diabetes of the young type 3 (MODY3) while some others do not cause MODY3 but increase the susceptibility to T2D or GDM. The phenotypes of MODY3 caused by different SNPs also differ. MODY3 is among the most common types of MODY, which is a form of monogenic diabetes mellitus caused by a single gene mutation. Both T2D and GDM are multifactorial diseases caused by both genetic and environmental factors. Different types of diabetes mellitus have different clinical phenotypes and treatments. This review focuses on HNF1α gene polymorphisms, HNF1A-MODY3, HNF1A-associated T2D and GDM, and the related pathogenesis and treatment methods. We hope this review will provide a valuable reference for the precise and individualized treatment of diabetes caused by abnormal HNF1α by summarizing the clinical heterogeneity of blood glucose abnormalities caused by HNF1α mutation.
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Affiliation(s)
- Li-Mei Li
- Research Center for Translational Medicine, Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Bei-Ge Jiang
- Third Department of Hepatic Surgery, Eastern Hepatobiliary Surgery Hospital, Naval Medical University, Shanghai, China
- *Correspondence: Bei-Ge Jiang, ; Liang-Liang Sun,
| | - Liang-Liang Sun
- Department of Endocrinology and Metabolism, Changzheng Hospital, Naval Medical University, Shanghai, China
- *Correspondence: Bei-Ge Jiang, ; Liang-Liang Sun,
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4
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Fairweather SJ, Shah N, Brӧer S. Heteromeric Solute Carriers: Function, Structure, Pathology and Pharmacology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 21:13-127. [PMID: 33052588 DOI: 10.1007/5584_2020_584] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Solute carriers form one of three major superfamilies of membrane transporters in humans, and include uniporters, exchangers and symporters. Following several decades of molecular characterisation, multiple solute carriers that form obligatory heteromers with unrelated subunits are emerging as a distinctive principle of membrane transporter assembly. Here we comprehensively review experimentally established heteromeric solute carriers: SLC3-SLC7 amino acid exchangers, SLC16 monocarboxylate/H+ symporters and basigin/embigin, SLC4A1 (AE1) and glycophorin A exchanger, SLC51 heteromer Ost α-Ost β uniporter, and SLC6 heteromeric symporters. The review covers the history of the heteromer discovery, transporter physiology, structure, disease associations and pharmacology - all with a focus on the heteromeric assembly. The cellular locations, requirements for complex formation, and the functional role of dimerization are extensively detailed, including analysis of the first complete heteromer structures, the SLC7-SLC3 family transporters LAT1-4F2hc, b0,+AT-rBAT and the SLC6 family heteromer B0AT1-ACE2. We present a systematic analysis of the structural and functional aspects of heteromeric solute carriers and conclude with common principles of their functional roles and structural architecture.
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Affiliation(s)
- Stephen J Fairweather
- Research School of Biology, Australian National University, Canberra, ACT, Australia. .,Resarch School of Chemistry, Australian National University, Canberra, ACT, Australia.
| | - Nishank Shah
- Research School of Biology, Australian National University, Canberra, ACT, Australia
| | - Stefan Brӧer
- Research School of Biology, Australian National University, Canberra, ACT, Australia.
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5
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Pillai NR, Yubero D, Shayota BJ, Oyarzábal A, Ghosh R, Sun Q, Azamian MS, Arjona C, Brandi N, Palau F, Lalani SR, Artuch R, García‐Cazorla A, Scott DA. Loss of CLTRN function produces a neuropsychiatric disorder and a biochemical phenotype that mimics Hartnup disease. Am J Med Genet A 2019; 179:2459-2468. [DOI: 10.1002/ajmg.a.61357] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/22/2019] [Accepted: 08/25/2019] [Indexed: 01/02/2023]
Affiliation(s)
- Nishitha R. Pillai
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
- Texas Children's Hospital Houston Texas
| | - Delia Yubero
- Department of Genetics and Molecular Medicine‐IPER, Institut de Recerca Sant Joan de Déu and CIBERER (ISCIII) Hospital Sant Joan de Déu Barcelona Spain
| | - Brian J. Shayota
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
- Texas Children's Hospital Houston Texas
| | - Alfonso Oyarzábal
- Laboratory of Synaptic Metabolism, Institut de Recerca Sant Joan de Déu and CIBERER (ISCIII) Hospital Sant Joan de Déu Barcelona Spain
| | - Rajarshi Ghosh
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
- Baylor Genetics Laboratory Houston Texas
| | - Qin Sun
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
- Baylor Genetics Laboratory Houston Texas
| | - Mahshid S. Azamian
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
- Texas Children's Hospital Houston Texas
| | - Cesar Arjona
- Department of Genetics and Molecular Medicine‐IPER, Institut de Recerca Sant Joan de Déu and CIBERER (ISCIII) Hospital Sant Joan de Déu Barcelona Spain
| | - Núria Brandi
- Department of Genetics and Molecular Medicine‐IPER, Institut de Recerca Sant Joan de Déu and CIBERER (ISCIII) Hospital Sant Joan de Déu Barcelona Spain
- School of Medicine Universitat de Barcelona Barcelona Spain
| | - Francesc Palau
- Department of Genetics and Molecular Medicine‐IPER, Institut de Recerca Sant Joan de Déu and CIBERER (ISCIII) Hospital Sant Joan de Déu Barcelona Spain
- Division of Pediatrics University of Barcelona School of Medicine and Health Sciences, and Institute of Medicine and Dermatology, Hospital Clínic Barcelona Spain
| | - Seema R. Lalani
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
- Texas Children's Hospital Houston Texas
| | - Rafael Artuch
- Department of Clinical Biochemistry, Institut de Recerca Sant Joan de Déu and CIBERER (ISCIII) Hospital Sant Joan de Déu Barcelona Spain
| | - Angeles García‐Cazorla
- Laboratory of Synaptic Metabolism, Institut de Recerca Sant Joan de Déu and CIBERER (ISCIII) Hospital Sant Joan de Déu Barcelona Spain
- Neurometabolic Unit, Department of Neurology Institut de Recerca, Sant Joan de Déu metabERN and CIBERER (ISCIII), Hospital Sant Joan de Déu Barcelona Spain
| | - Daryl A. Scott
- Department of Molecular and Human Genetics Baylor College of Medicine Houston Texas
- Texas Children's Hospital Houston Texas
- Department of Molecular Physiology and Biophysics Baylor College of Medicine Houston Texas
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6
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Abstract
The small intestine mediates the absorption of amino acids after ingestion of protein and sustains the supply of amino acids to all tissues. The small intestine is an important contributor to plasma amino acid homeostasis, while amino acid transport in the large intestine is more relevant for bacterial metabolites and fluid secretion. A number of rare inherited disorders have contributed to the identification of amino acid transporters in epithelial cells of the small intestine, in particular cystinuria, lysinuric protein intolerance, Hartnup disorder, iminoglycinuria, and dicarboxylic aminoaciduria. These are most readily detected by analysis of urine amino acids, but typically also affect intestinal transport. The genes underlying these disorders have all been identified. The remaining transporters were identified through molecular cloning techniques to the extent that a comprehensive portrait of functional cooperation among transporters of intestinal epithelial cells is now available for both the basolateral and apical membranes. Mouse models of most intestinal transporters illustrate their contribution to amino acid homeostasis and systemic physiology. Intestinal amino acid transport activities can vary between species, but these can now be explained as differences of amino acid transporter distribution along the intestine. © 2019 American Physiological Society. Compr Physiol 9:343-373, 2019.
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Affiliation(s)
- Stefan Bröer
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| | - Stephen J Fairweather
- Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
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7
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Cheng Q, Shah N, Bröer A, Fairweather S, Jiang Y, Schmoll D, Corry B, Bröer S. Identification of novel inhibitors of the amino acid transporter B 0 AT1 (SLC6A19), a potential target to induce protein restriction and to treat type 2 diabetes. Br J Pharmacol 2017; 174:468-482. [PMID: 28176326 DOI: 10.1111/bph.13711] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 12/28/2016] [Accepted: 01/04/2017] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND AND PURPOSE The neutral amino acid transporter B0 AT1 (SLC6A19) has recently been identified as a possible target to treat type 2 diabetes and related disorders. B0 AT1 mediates the Na+ -dependent uptake of all neutral amino acids. For surface expression and catalytic activity, B0 AT1 requires coexpression of collectrin (TMEM27). In this study, we established tools to identify and evaluate novel inhibitors of B0 AT1. EXPERIMENTAL APPROACH A CHO-based cell line was generated, stably expressing collectrin and B0 AT1. Using this cell line, a high-throughput screening assay was developed, which uses a fluorescent dye to detect depolarisation of the cell membrane during amino acid uptake via B0 AT1. In parallel to these functional assays, we ran a computational compound screen using AutoDock4 and a homology model of B0 AT1 based on the high-resolution structure of the highly homologous Drosophila dopamine transporter. KEY RESULTS We characterized a series of novel inhibitors of the B0 AT1 transporter. Benztropine was identified as a competitive inhibitor of the transporter showing an IC50 of 44 ± 9 μM. The compound was selective with regard to related transporters and blocked neutral amino acid uptake in inverted sections of mouse intestine. CONCLUSION AND IMPLICATIONS The tools established in this study can be widely used to identify new transport inhibitors. Using these tools, we were able to identify compounds that can be used to study epithelial transport, to induce protein restriction, or be developed further through medicinal chemistry.
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Affiliation(s)
- Qi Cheng
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Nishank Shah
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Angelika Bröer
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Stephen Fairweather
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Yang Jiang
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Dieter Schmoll
- Industriepark Hoechst, Sanofi-Aventis Deutschland GmbH, Frankfurt am Main, Germany
| | - Ben Corry
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Stefan Bröer
- Research School of Biology, The Australian National University, Canberra, Australia
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8
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Chu PL, Gigliotti JC, Cechova S, Bodonyi-Kovacs G, Chan F, Ralph DL, Howell N, Kalantari K, Klibanov AL, Carey RM, McDonough AA, Le TH. Renal Collectrin Protects against Salt-Sensitive Hypertension and Is Downregulated by Angiotensin II. J Am Soc Nephrol 2017; 28:1826-1837. [PMID: 28062568 DOI: 10.1681/asn.2016060675] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 11/28/2016] [Indexed: 12/13/2022] Open
Abstract
Collectrin, encoded by the Tmem27 gene, is a transmembrane glycoprotein with approximately 50% homology with angiotensin converting enzyme 2, but without a catalytic domain. Collectrin is most abundantly expressed in the kidney proximal tubule and collecting duct epithelia, where it has an important role in amino acid transport. Collectrin is also expressed in endothelial cells throughout the vasculature, where it regulates L-arginine uptake. We previously reported that global deletion of collectrin leads to endothelial dysfunction, augmented salt sensitivity, and hypertension. Here, we performed kidney crosstransplants between wild-type (WT) and collectrin knockout (Tmem27Y/- ) mice to delineate the specific contribution of renal versus extrarenal collectrin on BP regulation and salt sensitivity. On a high-salt diet, WT mice with Tmem27Y/- kidneys had the highest systolic BP and were the only group to exhibit glomerular mesangial hypercellularity. Additional studies showed that, on a high-salt diet, Tmem27Y/- mice had lower renal blood flow, higher abundance of renal sodium-hydrogen antiporter 3, and lower lithium clearance than WT mice. In WT mice, administration of angiotensin II for 2 weeks downregulated collectrin expression in a type 1 angiotensin II receptor-dependent manner. This downregulation coincided with the onset of hypertension, such that WT and Tmem27Y/- mice had similar levels of hypertension after 2 weeks of angiotensin II administration. Altogether, these data suggest that salt sensitivity is determined by intrarenal collectrin, and increasing the abundance or activity of collectrin may have therapeutic benefits in the treatment of hypertension and salt sensitivity.
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Affiliation(s)
| | - Joseph C Gigliotti
- Division of Nephrology.,Department of Integrated Physiology and Pharmacology, Liberty University College of Osteopathic Medicine, Lynchburg, Virginia; and
| | | | | | | | - Donna Lee Ralph
- Department of Cell and Neurobiology, University of Southern California, Keck School of Medicine, Los Angeles, California
| | - Nancy Howell
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia
| | | | | | - Robert M Carey
- Division of Endocrinology, Department of Medicine, University of Virginia Health System, Charlottesville, Virginia
| | - Alicia A McDonough
- Department of Cell and Neurobiology, University of Southern California, Keck School of Medicine, Los Angeles, California
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9
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Shoemaker R, Yiannikouris F, Thatcher S, Cassis L. ACE2 deficiency reduces β-cell mass and impairs β-cell proliferation in obese C57BL/6 mice. Am J Physiol Endocrinol Metab 2015; 309:E621-31. [PMID: 26389599 PMCID: PMC4593774 DOI: 10.1152/ajpendo.00054.2015] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 07/31/2015] [Indexed: 12/13/2022]
Abstract
Drugs that inhibit the renin-angiotensin system (RAS) decrease the onset of type 2 diabetes (T2D). Pancreatic islets express RAS components, including angiotensin-converting enzyme 2 (ACE2), which cleaves angiotensin II (Ang II) to angiotensin-(1-7) [Ang-(1-7)]. Overexpression of ACE2 in pancreas of diabetic mice improved glucose homeostasis. The purpose of this study was to determine if deficiency of endogenous ACE2 contributes to islet dysfunction and T2D. We hypothesized that ACE2 deficiency potentiates the decline in β-cell function and augments the development of diet-induced T2D. Male Ace2(+/y) or Ace2(-/y) mice were fed a low-fat (LF) or high-fat (HF) diet for 1 or 4 mo. A subset of 1-mo HF-fed mice were infused with Sal (Sal), losartan (Los), or Ang-(1-7). At 4 mo, while both genotypes of HF-fed mice developed a similar level of insulin resistance, adaptive hyperinsulinemia was reduced in Ace2(-/y) vs. Ace2(+/y) mice. Similarly, in vivo glucose-stimulated insulin secretion (GSIS) was reduced in 1-mo HF-fed Ace2(-/y) compared with Ace2(+/y) mice, resulting in augmented hyperglycemia. The average islet area was significantly smaller in both LF- and HF-fed Ace2(-/y) vs. Ace2(+/y) mice. Additionally, β-cell mass and proliferation were reduced significantly in HF-fed Ace2(-/y) vs. Ace2(+/y) mice. Neither infusion of Los nor Ang-(1-7) was able to correct impaired in vivo GSIS of HF-fed ACE2-deficient mice. These results demonstrate a critical role for endogenous ACE2 in the adaptive β-cell hyperinsulinemic response to HF feeding through regulation of β-cell proliferation and growth.
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Affiliation(s)
- Robin Shoemaker
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky
| | - Frederique Yiannikouris
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky
| | - Sean Thatcher
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky
| | - Lisa Cassis
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, Kentucky
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10
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Jiang Y, Rose AJ, Sijmonsma TP, Bröer A, Pfenninger A, Herzig S, Schmoll D, Bröer S. Mice lacking neutral amino acid transporter B(0)AT1 (Slc6a19) have elevated levels of FGF21 and GLP-1 and improved glycaemic control. Mol Metab 2015; 4:406-17. [PMID: 25973388 PMCID: PMC4421019 DOI: 10.1016/j.molmet.2015.02.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 02/05/2015] [Accepted: 02/09/2015] [Indexed: 02/07/2023] Open
Abstract
OBJECTIVE Type 2 diabetes arises from insulin resistance of peripheral tissues followed by dysfunction of β-cells in the pancreas due to metabolic stress. Both depletion and supplementation of neutral amino acids have been discussed as strategies to improve insulin sensitivity. Here we characterise mice lacking the intestinal and renal neutral amino acid transporter B(0)AT1 (Slc6a19) as a model to study the consequences of selective depletion of neutral amino acids. METHODS Metabolic tests, analysis of metabolite levels and signalling pathways were used to characterise mice lacking the intestinal and renal neutral amino acid transporter B(0)AT1 (Slc6a19). RESULTS Reduced uptake of neutral amino acids in the intestine and loss of neutral amino acids in the urine causes an overload of amino acids in the lumen of the intestine and reduced systemic amino acid availability. As a result, higher levels of glucagon-like peptide 1 (GLP-1) are produced by the intestine after a meal, while the liver releases the starvation hormone fibroblast growth factor 21 (FGF21). The combination of these hormones generates a metabolic phenotype that is characterised by efficient removal of glucose, particularly by the heart, reduced adipose tissue mass, browning of subcutaneous white adipose tissue, enhanced production of ketone bodies and reduced hepatic glucose output. CONCLUSIONS Reduced neutral amino acid availability improves glycaemic control. The epithelial neutral amino acid transporter B(0)AT1 could be a suitable target to treat type 2 diabetes.
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Affiliation(s)
- Yang Jiang
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Adam J. Rose
- Joint Research Division Molecular Metabolic Control, German Cancer Research Center, Center for Molecular Biology, Heidelberg University and Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Tjeerd P. Sijmonsma
- Joint Research Division Molecular Metabolic Control, German Cancer Research Center, Center for Molecular Biology, Heidelberg University and Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Angelika Bröer
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Anja Pfenninger
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main 65926, Germany
| | - Stephan Herzig
- Joint Research Division Molecular Metabolic Control, German Cancer Research Center, Center for Molecular Biology, Heidelberg University and Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Dieter Schmoll
- Sanofi-Aventis Deutschland GmbH, Industriepark Hoechst, Frankfurt am Main 65926, Germany
| | - Stefan Bröer
- Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
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11
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Sparks MA, Crowley SD, Gurley SB, Mirotsou M, Coffman TM. Classical Renin-Angiotensin system in kidney physiology. Compr Physiol 2015; 4:1201-28. [PMID: 24944035 DOI: 10.1002/cphy.c130040] [Citation(s) in RCA: 353] [Impact Index Per Article: 39.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The renin-angiotensin system has powerful effects in control of the blood pressure and sodium homeostasis. These actions are coordinated through integrated actions in the kidney, cardiovascular system and the central nervous system. Along with its impact on blood pressure, the renin-angiotensin system also influences a range of processes from inflammation and immune responses to longevity. Here, we review the actions of the "classical" renin-angiotensin system, whereby the substrate protein angiotensinogen is processed in a two-step reaction by renin and angiotensin converting enzyme, resulting in the sequential generation of angiotensin I and angiotensin II, the major biologically active renin-angiotensin system peptide, which exerts its actions via type 1 and type 2 angiotensin receptors. In recent years, several new enzymes, peptides, and receptors related to the renin-angiotensin system have been identified, manifesting a complexity that was previously unappreciated. While the functions of these alternative pathways will be reviewed elsewhere in this journal, our focus here is on the physiological role of components of the "classical" renin-angiotensin system, with an emphasis on new developments and modern concepts.
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Affiliation(s)
- Matthew A Sparks
- Division of Nephrology, Department of Medicine, Duke University Medical Center, Durham, North Carolina
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12
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Abstract
PURPOSE OF REVIEW Epithelial neutral amino acid transporters have been identified at the molecular level in recent years. Mouse models have now established the crucial role of these transporters for systemic amino acid homeostasis. This review summarizes recent progress in this field. RECENT FINDINGS Epithelial neutral amino acid transporters play an important role in the homeostasis of neutral amino acid levels in the body. They are important for the maintenance of body weight and muscle mass and serve as fuels. They also serve a role in providing nutrients to epithelial cells. Changes of plasma amino acid levels are not necessarily correlated to the amino acids appearing in the urine; changes in organ amino acid metabolism need to be taken into account. SUMMARY Genetic deletion of neutral amino acid transporters provides insight into their role in protein nutrition and homeostasis.
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Perlot T, Penninger JM. ACE2 - from the renin-angiotensin system to gut microbiota and malnutrition. Microbes Infect 2013; 15:866-73. [PMID: 23962453 PMCID: PMC7110844 DOI: 10.1016/j.micinf.2013.08.003] [Citation(s) in RCA: 164] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 08/06/2013] [Indexed: 02/07/2023]
Abstract
The renin-angiotensin system (RAS) is a complex network that regulates blood pressure, electrolyte and fluid homeostasis, as well as the function of several organs. Angiotensin-converting enzyme 2 (ACE2) was identified as an enzyme that negatively regulates the RAS by converting Ang II, the main bioactive molecule of the RAS, to Ang 1-7. Thus, ACE2 counteracts the role of angiotensin-converting enzyme (ACE) which generates Ang II from Ang I. ACE and ACE2 have been implicated in several pathologies such as cardiovascular and renal disease or acute lung injury. In addition, ACE2 has functions independent of the RAS: ACE2 is the receptor for the SARS coronavirus and ACE2 is essential for expression of neutral amino acid transporters in the gut. In this context, ACE2 modulates innate immunity and influences the composition of the gut microbiota, which can explain diarrhea and intestinal inflammation observed in Hartnup disorder, Pellagra, or under conditions of severe malnutrition. Here we review and discuss the diverse functions of ACE2 and its relevance to human pathologies.
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Affiliation(s)
- Thomas Perlot
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
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Burgos-Ramos E, Canelles S, Perianes-Cachero A, Arilla-Ferreiro E, Argente J, Barrios V. Adipose tissue promotes a serum cytokine profile related to lower insulin sensitivity after chronic central leptin infusion. PLoS One 2012; 7:e46893. [PMID: 23056516 PMCID: PMC3462753 DOI: 10.1371/journal.pone.0046893] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Accepted: 09/10/2012] [Indexed: 12/13/2022] Open
Abstract
Obesity is an inflammatory state characterized by an augment in circulating inflammatory factors. Leptin may modulate the synthesis of these factors by white adipose tissue decreasing insulin sensitivity. We have examined the effect of chronic central administration of leptin on circulating levels of cytokines and the possible relationship with cytokine expression and protein content as well as with leptin and insulin signaling in subcutaneous and visceral adipose tissues. In addition, we analyzed the possible correlation between circulating levels of cytokines and peripheral insulin resistance. We studied 18 male Wistar rats divided into controls (C), those treated icv for 14 days with a daily dose of 12 μg of leptin (L) and a pair-fed group (PF) that received the same food amount consumed by the leptin group. Serum leptin and insulin were measured by ELISA, mRNA levels of interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4, IL-6, IL-10 and tumor necrosis factor-α (TNF-α) by real time PCR and serum and adipose tissue levels of these cytokines by multiplexed bead immunoassay. Serum leptin, IL-2, IL-4, IFN-γ and HOMA-IR were increased in L and TNF-α was decreased in PF and L. Serum leptin and IL-2 levels correlate positively with HOMA-IR index and negatively with serum glucose levels during an ip insulin tolerance test. In L, an increase in mRNA levels of IL-2 was found in both adipose depots and IFN-γ only in visceral tissue. Activation of leptin signaling was increased and insulin signaling decreased in subcutaneous fat of L. In conclusion, leptin mediates the production of inflammatory cytokines by adipose tissue independent of its effects on food intake, decreasing insulin sensitivity.
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Affiliation(s)
- Emma Burgos-Ramos
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Sandra Canelles
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Arancha Perianes-Cachero
- Grupo de Neurobioquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Eduardo Arilla-Ferreiro
- Grupo de Neurobioquímica, Departamento de Bioquímica y Biología Molecular, Facultad de Medicina, Universidad de Alcalá, Alcalá de Henares, Spain
| | - Jesús Argente
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Vicente Barrios
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa and Department of Pediatrics, Universidad Autónoma de Madrid, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
- * E-mail:
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15
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Hald J, Galbo T, Rescan C, Radzikowski L, Sprinkel AE, Heimberg H, Ahnfelt-Rønne J, Jensen J, Scharfmann R, Gradwohl G, Kaestner KH, Stoeckert C, Jensen JN, Madsen OD. Pancreatic islet and progenitor cell surface markers with cell sorting potential. Diabetologia 2012; 55:154-65. [PMID: 21947380 DOI: 10.1007/s00125-011-2295-1] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2011] [Accepted: 07/12/2011] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS The aim of the study was to identify surface bio-markers and corresponding antibody tools that can be used for the imaging and immunoisolation of the pancreatic beta cell and its progenitors. This may prove essential to obtain therapeutic grade human beta cells via stem cell differentiation. METHODS Using bioinformatics-driven data mining, we generated a gene list encoding putative plasma membrane proteins specifically expressed at distinct stages of the developing pancreas and islet beta cells. In situ hybridisation and immunohistochemistry were used to further prioritise and identify candidates. RESULTS In the developing pancreas seizure related 6 homologue like (SEZ6L2), low density lipoprotein receptor-related protein 11 (LRP11), dispatched homologue 2 (Drosophila) (DISP2) and solute carrier family 30 (zinc transporter), member 8 (SLC30A8) were found to be expressed in early islet cells, whereas discoidin domain receptor tyrosine kinase 1 (DDR1) and delta/notch-like EGF repeat containing (DNER) were expressed in early pancreatic progenitors. The expression pattern of DDR1 overlaps with the early pancreatic and duodenal homeobox 1 (PDX1)⁺/NK6 homeobox 1 (NKX6-1)⁺ multipotent progenitor cells from embryonic day 11, whereas DNER expression in part overlaps with neurogenin 3 (NEUROG3)⁺ cells. In the adult pancreas SEZ6L2, LRP11, DISP2 and SLC30A8, but also FXYD domain containing ion transport regulator 2 (FXYD2), tetraspanin 7 (TSPAN7) and transmembrane protein 27 (TMEM27), retain an islet-specific expression, whereas DDR1 is undetectable. In contrast, DNER is expressed at low levels in peripheral mouse and human islet cells. Re-expression of DDR1 and upregulation of DNER is observed in duct-ligated pancreas. Antibodies to DNER and DISP2 have been successfully used in cell sorting. CONCLUSIONS/INTERPRETATION Extracellular epitopes of SEZ6L2, LRP11, DISP2, DDR1 and DNER have been identified as useful tags by applying specific antibodies to visualise pancreatic cell types at specific stages of development. Furthermore, antibodies recognising DISP2 and DNER are suitable for FACS-mediated cell purification.
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Affiliation(s)
- J Hald
- Department of Beta-Cell Regeneration, Hagedorn Research Institute, Niels Steensens Vej 1, 2820 Gentofte, Denmark
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Angiotensin-converting enzyme 2: the first decade. Int J Hypertens 2011; 2012:307315. [PMID: 22121476 PMCID: PMC3216391 DOI: 10.1155/2012/307315] [Citation(s) in RCA: 162] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 08/25/2011] [Indexed: 12/25/2022] Open
Abstract
The renin-angiotensin system (RAS) is a critical regulator of hypertension, primarily through the actions of the vasoactive peptide Ang II, which is generated by the action of angiotensin-converting enzyme (ACE) mediating an increase in blood pressure. The discovery of ACE2, which primarily metabolises Ang II into the vasodilatory Ang-(1-7), has added a new dimension to the traditional RAS. As a result there has been huge interest in ACE2 over the past decade as a potential therapeutic for lowering blood pressure, especially elevation resulting from excess Ang II. Studies focusing on ACE2 have helped to reveal other actions of Ang-(1-7), outside vasodilation, such as antifibrotic and antiproliferative effects. Moreover, investigations focusing on ACE2 have revealed a variety of roles not just catalytic but also as a viral receptor and amino acid transporter. This paper focuses on what is known about ACE2 and its biological roles, paying particular attention to the regulation of ACE2 expression. In light of the entrance of human recombinant ACE2 into clinical trials, we discuss the potential use of ACE2 as a therapeutic and highlight some pertinent questions that still remain unanswered about ACE2.
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17
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Bace2 is a β cell-enriched protease that regulates pancreatic β cell function and mass. Cell Metab 2011; 14:365-77. [PMID: 21907142 DOI: 10.1016/j.cmet.2011.06.018] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2011] [Revised: 05/11/2011] [Accepted: 06/22/2011] [Indexed: 11/23/2022]
Abstract
Decreased β cell mass and function are hallmarks of type 2 diabetes. Here we identified, through a siRNA screen, beta site amyloid precursor protein cleaving enzyme 2 (Bace2) as the sheddase of the proproliferative plasma membrane protein Tmem27 in murine and human β cells. Mice with functionally inactive Bace2 and insulin-resistant mice treated with a newly identified Bace2 inhibitor both display augmented β cell mass and improved control of glucose homeostasis due to increased insulin levels. These results implicate Bace2 in the control of β cell maintenance and provide a rational strategy to inhibit this protease for the expansion of functional pancreatic β cell mass.
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Altirriba J, Gasa R, Casas S, Ramírez-Bajo MJ, Ros S, Gutierrez-Dalmau A, Ruiz de Villa MC, Barbera A, Gomis R. The role of transmembrane protein 27 (TMEM27) in islet physiology and its potential use as a beta cell mass biomarker. Diabetologia 2010; 53:1406-14. [PMID: 20386877 PMCID: PMC7096040 DOI: 10.1007/s00125-010-1728-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Accepted: 01/28/2010] [Indexed: 12/19/2022]
Abstract
AIMS/HYPOTHESIS Transmembrane protein 27 (TMEM27) is a membrane protein cleaved and shed by pancreatic beta cells that has been proposed as a beta cell mass biomarker. Despite reports of its possible role in insulin exocytosis and cell proliferation, its function in beta cells remains controversial. We aimed to characterise the function of TMEM27 in islets and its potential use as a beta cell mass biomarker. METHODS To determine TMEM27 function, we studied TMEM27 gene expression and localisation in human healthy and diabetic islets, the correlation of its expression with cell cycle and insulin secretion genes in human islets, its expression in tungstate-treated rats, and the effects of its overproduction on insulin secretion and proliferation in a beta cell line and islets. To elucidate its utility as a beta cell mass biomarker, we studied TMEM27 cleavage in a beta cell line, islets and primary proximal tubular cells. RESULTS TMEM27 mRNA levels in islets are lower in diabetic donors than in controls. Its gene expression correlates with that of insulin and SNAPIN in human islets. TMEM27 expression is downregulated in islets of tungstate-treated rats, which exhibit decreased insulin secretion and increased proliferation. TMEM27 overproduction in a beta cell line and islets significantly enhanced glucose-induced insulin secretion, with modest or no effects on proliferation. Finally, TMEM27 is cleaved and shed by renal proximal tubular cells and pancreatic islets. CONCLUSIONS/INTERPRETATION Our data support a role for TMEM27 in glucose-induced insulin secretion but not in cell proliferation. The finding that its cleavage is not specific to beta cells challenges the current support for its use as a potential beta cell mass biomarker.
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Affiliation(s)
- J. Altirriba
- grid.5841.80000000419370247Laboratory of Diabetes and Obesity, Endocrinology and Nutrition Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic de Barcelona, Villarroel 170, 08036 Barcelona, Spain
- grid.430579.cCentro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Spain,
| | - R. Gasa
- grid.5841.80000000419370247Laboratory of Diabetes and Obesity, Endocrinology and Nutrition Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic de Barcelona, Villarroel 170, 08036 Barcelona, Spain
- grid.430579.cCentro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Spain,
| | - S. Casas
- grid.5841.80000000419370247Laboratory of Diabetes and Obesity, Endocrinology and Nutrition Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic de Barcelona, Villarroel 170, 08036 Barcelona, Spain
- grid.430579.cCentro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Spain,
| | - M. J. Ramírez-Bajo
- grid.410458.c0000000096359413Department of Nephrology and Renal Transplantation, Laboratori Experimental de Nefrologia i Trasplantament, Hospital Clínic i Provincial de Barcelona, Barcelona, Spain
| | - S. Ros
- grid.7722.00000000118116966Institute for Research in Biomedicine, Scientific Park, Barcelona, Spain
| | - A. Gutierrez-Dalmau
- grid.410458.c0000000096359413Department of Nephrology and Renal Transplantation, Laboratori Experimental de Nefrologia i Trasplantament, Hospital Clínic i Provincial de Barcelona, Barcelona, Spain
- grid.411106.30000000098542756Department of Nephrology, Hospital Universitario Miguel Servet, Zaragoza, Spain
| | - M. C. Ruiz de Villa
- grid.5841.80000000419370247Department of Statistics, University of Barcelona, Barcelona, Spain
| | - A. Barbera
- grid.5841.80000000419370247Laboratory of Diabetes and Obesity, Endocrinology and Nutrition Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic de Barcelona, Villarroel 170, 08036 Barcelona, Spain
| | - R. Gomis
- grid.5841.80000000419370247Laboratory of Diabetes and Obesity, Endocrinology and Nutrition Unit, Institut d’Investigacions Biomèdiques August Pi i Sunyer, Hospital Clinic de Barcelona, Villarroel 170, 08036 Barcelona, Spain
- grid.430579.cCentro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas, Spain,
- grid.5841.80000000419370247Department of Medicine, University of Barcelona, Barcelona, Spain
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Lambert DW, Clarke NE, Turner AJ. Not just angiotensinases: new roles for the angiotensin-converting enzymes. Cell Mol Life Sci 2010; 67:89-98. [PMID: 19763395 PMCID: PMC7079792 DOI: 10.1007/s00018-009-0152-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 08/27/2009] [Accepted: 08/27/2009] [Indexed: 01/07/2023]
Abstract
The renin-angiotensin system (RAS) is a critical regulator of blood pressure and fluid homeostasis. Angiotensin II, the primary bioactive peptide of the RAS, is generated from angiotensin I by angiotensin-converting enzyme (ACE). A homologue of ACE, ACE2, is able to convert angiotensin II to a peptide with opposing effects, angiotensin-(1-7). It is proposed that disturbance of the balance of ACE and ACE2 expression and/or function is important in pathologies in which angiotensin II plays a role. These include cardiovascular and renal disease, lung injury and liver fibrosis. The critical roles of ACE and ACE2 in regulating angiotensin II levels have traditionally focussed attention on their activities as angiotensinases. Recent discoveries, however, have illuminated the roles of these enzymes and of the ACE2 homologue, collectrin, in intracellular trafficking and signalling. This paper reviews the key literature regarding both the catalytic and non-catalytic roles of the angiotensin-converting enzyme gene family.
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Affiliation(s)
- Daniel W Lambert
- Oral and Maxillofacial Pathology, Faculty of Medicine, Dentistry and Health, University of Sheffield, S10 2TA, Sheffield, UK.
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Anderson KR, White P, Kaestner KH, Sussel L. Identification of known and novel pancreas genes expressed downstream of Nkx2.2 during development. BMC DEVELOPMENTAL BIOLOGY 2009; 9:65. [PMID: 20003319 PMCID: PMC2799404 DOI: 10.1186/1471-213x-9-65] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Accepted: 12/10/2009] [Indexed: 11/10/2022]
Abstract
BACKGROUND The homeodomain containing transcription factor Nkx2.2 is essential for the differentiation of pancreatic endocrine cells. Deletion of Nkx2.2 in mice leads to misspecification of islet cell types; insulin-expressing beta cells and glucagon-expressing alpha cells are replaced by ghrelin-expressing cells. Additional studies have suggested that Nkx2.2 functions both as a transcriptional repressor and activator to regulate islet cell formation and function. To identify genes that are potentially regulated by Nkx2.2 during the major wave of endocrine and exocrine cell differentiation, we assessed gene expression changes that occur in the absence of Nkx2.2 at the onset of the secondary transition in the developing pancreas. RESULTS Microarray analysis identified 80 genes that were differentially expressed in e12.5 and/or e13.5 Nkx2.2-/- embryos. Some of these genes encode transcription factors that have been previously identified in the pancreas, clarifying the position of Nkx2.2 within the islet transcriptional regulatory pathway. We also identified signaling factors and transmembrane proteins that function downstream of Nkx2.2, including several that have not previously been described in the pancreas. Interestingly, a number of known exocrine genes are also misexpressed in the Nkx2.2-/- pancreas. CONCLUSIONS Expression profiling of Nkx2.2-/- mice during embryogenesis has allowed us to identify known and novel pancreatic genes that function downstream of Nkx2.2 to regulate pancreas development. Several of the newly identified signaling factors and transmembrane proteins may function to influence islet cell fate decisions. These studies have also revealed a novel function for Nkx2.2 in maintaining appropriate exocrine gene expression. Most importantly, Nkx2.2 appears to function within a complex regulatory loop with Ngn3 at a key endocrine differentiation step.
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Affiliation(s)
- Keith R Anderson
- Department of Biochemistry and Program in Molecular Biology, University of Colorado Health Science Center, Denver, CO 80045, USA
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Saisho K, Fukuhara A, Yasuda T, Sato Y, Fukui K, Iwahashi H, Imagawa A, Hatta M, Shimomura I, Yamagata K. Glucose enhances collectrin protein expression in insulin-producing MIN6 β cells. Biochem Biophys Res Commun 2009; 389:133-7. [DOI: 10.1016/j.bbrc.2009.08.111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Accepted: 08/20/2009] [Indexed: 11/30/2022]
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