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De Masi R, Orlando S. GANAB and N-Glycans Substrates Are Relevant in Human Physiology, Polycystic Pathology and Multiple Sclerosis: A Review. Int J Mol Sci 2022; 23:7373. [PMID: 35806376 PMCID: PMC9266668 DOI: 10.3390/ijms23137373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/22/2022] [Accepted: 06/28/2022] [Indexed: 11/29/2022] Open
Abstract
Glycans are one of the four fundamental macromolecular components of living matter, and they are highly regulated in the cell. Their functions are metabolic, structural and modulatory. In particular, ER resident N-glycans participate with the Glc3Man9GlcNAc2 highly conserved sequence, in protein folding process, where the physiological balance between glycosylation/deglycosylation on the innermost glucose residue takes place, according GANAB/UGGT concentration ratio. However, under abnormal conditions, the cell adapts to the glucose availability by adopting an aerobic or anaerobic regimen of glycolysis, or to external stimuli through internal or external recognition patterns, so it responds to pathogenic noxa with unfolded protein response (UPR). UPR can affect Multiple Sclerosis (MS) and several neurological and metabolic diseases via the BiP stress sensor, resulting in ATF6, PERK and IRE1 activation. Furthermore, the abnormal GANAB expression has been observed in MS, systemic lupus erythematous, male germinal epithelium and predisposed highly replicating cells of the kidney tubules and bile ducts. The latter is the case of Polycystic Liver Disease (PCLD) and Polycystic Kidney Disease (PCKD), where genetically induced GANAB loss affects polycystin-1 (PC1) and polycystin-2 (PC2), resulting in altered protein quality control and cyst formation phenomenon. Our topics resume the role of glycans in cell physiology, highlighting the N-glycans one, as a substrate of GANAB, which is an emerging key molecule in MS and other human pathologies.
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Affiliation(s)
- Roberto De Masi
- Complex Operative Unit of Neurology, “F. Ferrari” Hospital, Casarano, 73042 Lecce, Italy;
- Laboratory of Neuroproteomics, Multiple Sclerosis Centre, “F. Ferrari” Hospital, Casarano, 73042 Lecce, Italy
| | - Stefania Orlando
- Laboratory of Neuroproteomics, Multiple Sclerosis Centre, “F. Ferrari” Hospital, Casarano, 73042 Lecce, Italy
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Jokiaho AJ, Winchester M, Donovan CM. N-Hydroxyethyl-1-Deoxynojirimycin (Miglitol) Restores the Counterregulatory Response to Hypoglycemia Following Antecedent Hypoglycemia. Diabetes 2022; 71:1063-1072. [PMID: 35179550 DOI: 10.2337/db21-0859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 02/15/2022] [Indexed: 11/13/2022]
Abstract
Antecedent hypoglycemia suppresses the counterregulatory responses to subsequent hypoglycemic episodes, which can be prevented by normalizing portal-mesenteric vein (PMV) glycemia alone during the antecedent bout. Since the sodium-glucose transporter 3 receptor has been implicated in PMV glucosensing, we hypothesized that PMV infusion of the sodium-glucose cotransporter 3 receptor agonist N-hydroxyethyl-1-deoxynojirimycin (miglitol) would rescue the sympathoadrenal response to subsequent hypoglycemia. Rats underwent hyperinsulinemic-hypoglycemic clamps on 2 consecutive days without miglitol infusion (antecedent hypoglycemia without miglitol [HYPO]) or with miglitol infused upstream in the PMV, perfusing the glucosensors, or adjacent to the liver, bypassing PMV glucosensors, on day 1 or day 2. Control animals underwent day 1 euglycemic clamps, followed by hypoglycemic clamps on day 2. Peak epinephrine (EPI) responses for HYPO on day 2 were significantly blunted when compared with controls. Miglitol infusion on day 1 proved ineffective in restoring the EPI response following antecedent hypoglycemia, but day 2 miglitol infusion restored EPI responses to control levels. As norepinephrine and glucagon demonstrated similar responses, day 2 administration of miglitol effectively restored the counterregulatory response following antecedent hypoglycemia. In subsequent experiments, we demonstrate similar results with reduced miglitol infusion doses, approaching those currently prescribed for type 2 diabetes (correcting for rodent size), as well as the efficacy of oral miglitol administration in restoring the counterregulatory responses following antecedent hypoglycemia.
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Affiliation(s)
- Anne J Jokiaho
- Department of Biological Sciences, University of Southern California, Los Angeles, CA
| | - Matthew Winchester
- Department of Biological Sciences, University of Southern California, Los Angeles, CA
| | - Casey M Donovan
- Department of Biological Sciences, University of Southern California, Los Angeles, CA
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3
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Structural basis of the selective sugar transport in sodium-glucose cotransporters. J Mol Biol 2022; 434:167464. [DOI: 10.1016/j.jmb.2022.167464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 11/23/2022]
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Fernández-Pereira C, San Millán-Tejado B, Gallardo-Gómez M, Pérez-Márquez T, Alves-Villar M, Melcón-Crespo C, Fernández-Martín J, Ortolano S. Therapeutic Approaches in Lysosomal Storage Diseases. Biomolecules 2021; 11:biom11121775. [PMID: 34944420 PMCID: PMC8698519 DOI: 10.3390/biom11121775] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/23/2021] [Accepted: 11/24/2021] [Indexed: 02/07/2023] Open
Abstract
Lysosomal Storage Diseases are multisystemic disorders determined by genetic variants, which affect the proteins involved in lysosomal function and cellular metabolism. Different therapeutic approaches, which are based on the physiologic mechanisms that regulate lysosomal function, have been proposed for these diseases. Currently, enzyme replacement therapy, gene therapy, or small molecules have been approved or are under clinical development to treat lysosomal storage disorders. The present article reviews the main therapeutic strategies that have been proposed so far, highlighting possible limitations and future perspectives.
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Affiliation(s)
- Carlos Fernández-Pereira
- Rare Disease and Pediatric Medicine Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36312 Vigo, Spain; (C.F.-P.); (B.S.M.-T.); (M.G.-G.); (T.P.-M.); (M.A.-V.); (C.M.-C.); (J.F.-M.)
| | - Beatriz San Millán-Tejado
- Rare Disease and Pediatric Medicine Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36312 Vigo, Spain; (C.F.-P.); (B.S.M.-T.); (M.G.-G.); (T.P.-M.); (M.A.-V.); (C.M.-C.); (J.F.-M.)
| | - María Gallardo-Gómez
- Rare Disease and Pediatric Medicine Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36312 Vigo, Spain; (C.F.-P.); (B.S.M.-T.); (M.G.-G.); (T.P.-M.); (M.A.-V.); (C.M.-C.); (J.F.-M.)
| | - Tania Pérez-Márquez
- Rare Disease and Pediatric Medicine Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36312 Vigo, Spain; (C.F.-P.); (B.S.M.-T.); (M.G.-G.); (T.P.-M.); (M.A.-V.); (C.M.-C.); (J.F.-M.)
| | - Marta Alves-Villar
- Rare Disease and Pediatric Medicine Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36312 Vigo, Spain; (C.F.-P.); (B.S.M.-T.); (M.G.-G.); (T.P.-M.); (M.A.-V.); (C.M.-C.); (J.F.-M.)
| | - Cristina Melcón-Crespo
- Rare Disease and Pediatric Medicine Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36312 Vigo, Spain; (C.F.-P.); (B.S.M.-T.); (M.G.-G.); (T.P.-M.); (M.A.-V.); (C.M.-C.); (J.F.-M.)
- Department of Pediatrics, Hospital Álvaro Cunqueiro, SERGAS, 36213 Vigo, Spain
| | - Julián Fernández-Martín
- Rare Disease and Pediatric Medicine Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36312 Vigo, Spain; (C.F.-P.); (B.S.M.-T.); (M.G.-G.); (T.P.-M.); (M.A.-V.); (C.M.-C.); (J.F.-M.)
- Department of Internal Medicine, Hospital Álvaro Cunqueiro, SERGAS, 36213 Vigo, Spain
| | - Saida Ortolano
- Rare Disease and Pediatric Medicine Group, Galicia Sur Health Research Institute (IIS Galicia Sur), SERGAS-UVIGO, 36312 Vigo, Spain; (C.F.-P.); (B.S.M.-T.); (M.G.-G.); (T.P.-M.); (M.A.-V.); (C.M.-C.); (J.F.-M.)
- Correspondence: ; Tel.: +34-986217466
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Liu M, Wang Y, Ma Y, Zhang X, Zhang L, Nie L, Guo W, Zhao D, Zhang J, Yuan D, Yue L. Activation of SGLT3a in endometrial epithelial cells induces paracrine stromal cell decidualization. J Cell Physiol 2021; 237:1532-1546. [PMID: 34755904 DOI: 10.1002/jcp.30629] [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: 04/06/2021] [Revised: 10/20/2021] [Accepted: 10/22/2021] [Indexed: 11/11/2022]
Abstract
Endometrial epithelial cells (EECs) and stromal cells (ESCs) have a close functional association. During the peri-implantation period, EECs with enhanced functional activities secrete a variety of paracrine factors to promote the decidualization of ESCs. However, little is known about the specific process by which EECs secrete paracrine factors to induce the decidualization of ESCs. Some evidence suggests that the activation of sodium-glucose cotransporter 3a (SGLT3a) induces the depolarization of ESCs to affect their function. Therefore, SGLT3a acts as a sensor molecule in certain cell types. In this study, the expression of SGLT3a was investigated in EECs to determine whether its levels increased during the peri-implantation period in female mice. The activation of SGLT3a in mouse EECs induced Na+ -dependent depolarization of the cell membrane and an influx of extracellular Ca2+ , which further promoted the expression and release of the paracrine factors prostaglandin E2 (PGE2) and F2-alpha (PGF2α) by upregulating the expression of cyclooxygenase-2. In turn, PGE2 and PGF2α induced the decidualization of ESCs. Importantly, we identified SGLT3a as a key molecule involved in the cross-talk between EECs and ESCs during the process of uterine decidualization.
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Affiliation(s)
- Min Liu
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Yicheng Wang
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Yongdan Ma
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Xueqin Zhang
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Lixue Zhang
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Li Nie
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Wenjing Guo
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Dan Zhao
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Jinhu Zhang
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Dongzhi Yuan
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
| | - Limin Yue
- Department of Physiology, West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
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Lim WXJ, Gammon CS, von Hurst P, Chepulis L, Page RA. A Narrative Review of Human Clinical Trials on the Impact of Phenolic-Rich Plant Extracts on Prediabetes and Its Subgroups. Nutrients 2021; 13:nu13113733. [PMID: 34835989 PMCID: PMC8624625 DOI: 10.3390/nu13113733] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/17/2021] [Accepted: 10/21/2021] [Indexed: 12/12/2022] Open
Abstract
Phenolic-rich plant extracts have been demonstrated to improve glycemic control in individuals with prediabetes. However, there is increasing evidence that people with prediabetes are not a homogeneous group but exhibit different glycemic profiles leading to the existence of prediabetes subgroups. Prediabetes subgroups have been identified as: isolated impaired fasting glucose (IFG), isolated impaired glucose tolerance (IGT), and combined impaired fasting glucose and glucose intolerance (IFG/IGT). The present review investigates human clinical trials examining the hypoglycemic potential of phenolic-rich plant extracts in prediabetes and prediabetes subgroups. Artemisia princeps Pampanini, soy (Glycine max (L.) Merrill) leaf and Citrus junos Tanaka peel have been demonstrated to improve fasting glycemia and thus may be more useful for individuals with IFG with increasing hepatic insulin resistance. In contrast, white mulberry (Morus alba Linn.) leaf, persimmon (Diospyros kaki) leaf and Acacia. Mearnsii bark were shown to improve postprandial glycemia and hence may be preferably beneficial for individuals with IGT with increasing muscle insulin resistance. Elaeis guineensis leaf was observed to improve both fasting and postprandial glycemic measures depending on the dose. Current evidence remains scarce regarding the impact of the plant extracts on glycemic control in prediabetes subgroups and therefore warrants further study.
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Affiliation(s)
- Wen Xin Janice Lim
- School of Health Sciences, Massey University, Auckland 0632, New Zealand; (W.X.J.L.); (C.S.G.)
- Riddet Institute, Massey University, Palmerston North 4442, New Zealand
| | - Cheryl S. Gammon
- School of Health Sciences, Massey University, Auckland 0632, New Zealand; (W.X.J.L.); (C.S.G.)
| | - Pamela von Hurst
- School of Sport, Exercise and Nutrition, Massey University, Auckland 0632, New Zealand;
| | - Lynne Chepulis
- Waikato Medical Research Centre, Te Huataki Waiora School of Health, University of Waikato, Hamilton 3216, New Zealand;
| | - Rachel A. Page
- School of Health Sciences, Massey University, Wellington 6021, New Zealand
- Centre for Metabolic Health Research, Massey University, Auckland 0632, New Zealand
- Correspondence: ; Tel.: +64-4-801-5799 (ext. 63462)
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Lumbroso A, Berthonneau C, Beaudet I, Quintard JP, Planchat A, García-Moreno MI, Ortiz Mellet C, Le Grognec E. A versatile stereocontrolled synthesis of 2-deoxyiminosugar C-glycosides and their evaluation as glycosidase inhibitors. Org Biomol Chem 2021; 19:1083-1099. [PMID: 33427829 DOI: 10.1039/d0ob02249g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A highly enantioselective synthesis of (R,S) or (S,S)-2,6-disubstituted dehydropiperidines has been previously achieved through Sn/Li transmetalation of the corresponding stannylated dehydropiperidines or of their precursors. Herein, we successively consider their Upjohn's syn dihydroxylation and their anti-dihydroxylation via an epoxidation reaction followed by epoxide opening reaction. The stereochemical course of these reactions was first reported including the use of appropriate protecting groups before considering the conversion of the obtained compounds into NH or NMe iminosugar hydrochlorides. A primary evaluation of the designed iminosugar C-glycosides as glycosidase inhibitors suggests candidates for the selective inhibition of α-galactosidase, amyloglycosidase and naringinase. Beyond the reported results, the method constitutes a highly modulable route for the synthesis of well stereodefined iminosugar C-glycosides, an advantage which might be used for the design of iminosugars to enhance their biological properties.
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Ferté L, Marino A, Battault S, Bultot L, Van Steenbergen A, Bol A, Cumps J, Ginion A, Koepsell H, Dumoutier L, Hue L, Horman S, Bertrand L, Beauloye C. New insight in understanding the contribution of SGLT1 in cardiac glucose uptake: evidence for a truncated form in mice and humans. Am J Physiol Heart Circ Physiol 2021; 320:H838-H853. [PMID: 33416451 PMCID: PMC8082801 DOI: 10.1152/ajpheart.00736.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 12/17/2020] [Accepted: 12/17/2020] [Indexed: 01/10/2023]
Abstract
Although sodium glucose cotransporter 1 (SGLT1) has been identified as one of the major SGLT isoforms expressed in the heart, its exact role remains elusive. Evidence using phlorizin, the most common inhibitor of SGLTs, has suggested its role in glucose transport. However, phlorizin could also affect classical facilitated diffusion via glucose transporters (GLUTs), bringing into question the relevance of SGLT1 in overall cardiac glucose uptake. Accordingly, we assessed the contribution of SGLT1 in cardiac glucose uptake using the SGLT1 knockout mouse model, which lacks exon 1. Glucose uptake was similar in cardiomyocytes isolated from SGLT1-knockout (Δex1KO) and control littermate (WT) mice either under basal state, insulin, or hyperglycemia. Similarly, in vivo basal and insulin-stimulated cardiac glucose transport measured by micro-PET scan technology did not differ between WT and Δex1KO mice. Micromolar concentrations of phlorizin had no impact on glucose uptake in either isolated WT or Δex1KO-derived cardiomyocytes. However, higher concentrations (1 mM) completely inhibited insulin-stimulated glucose transport without affecting insulin signaling nor GLUT4 translocation independently from cardiomyocyte genotype. Interestingly, we discovered that mouse and human hearts expressed a shorter slc5a1 transcript, leading to SGLT1 protein lacking transmembrane domains and residues involved in glucose and sodium bindings. In conclusion, cardiac SGLT1 does not contribute to overall glucose uptake, probably due to the expression of slc5a1 transcript variant. The inhibitory effect of phlorizin on cardiac glucose uptake is SGLT1-independent and can be explained by GLUT transporter inhibition. These data open new perspectives in understanding the role of SGLT1 in the heart.NEW & NOTEWORTHY Ever since the discovery of its expression in the heart, SGLT1 has been considered as similar as the intestine and a potential contributor to cardiac glucose transport. For the first time, we have demonstrated that a slc5a1 transcript variant is present in the heart that has no significant impact on cardiac glucose handling.
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Affiliation(s)
- Laura Ferté
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Alice Marino
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Sylvain Battault
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Laurent Bultot
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Anne Van Steenbergen
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Anne Bol
- Center of Molecular Imaging, Radiotherapy and Oncology, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Julien Cumps
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Audrey Ginion
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Hermann Koepsell
- Department of Molecular Plant Physiology and Biophysics, Julius von Sachs Institute, University of Würzburg, Würzburg, Germany
| | - Laure Dumoutier
- Médecine Expérimentale, Institut de Duve, Université Catholique de Louvain, Brussels, Belgium
| | - Louis Hue
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
- Institut de Duve, Université Catholique de Louvain, Brussels, Belgium
| | - Sandrine Horman
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Luc Bertrand
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
| | - Christophe Beauloye
- Pôle de Recherche Cardiovasculaire, Institut de Recherche Expérimentale et Clinique, Université catholique de Louvain, Brussels, Belgium
- Division of Cardiology, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
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Klunda T, Hricovíni M, Šesták S, Kóňa J, Poláková M. Selective Golgi α-mannosidase II inhibitors: N-alkyl substituted pyrrolidines with a basic functional group. NEW J CHEM 2021. [DOI: 10.1039/d1nj01176f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Enzymatic assays, molecular modeling and NMR studies of novel 1,4-dideoxy-1,4-imino-l-lyxitols provided new information on the GH38 family enzyme inhibitors and their selectivity.
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Affiliation(s)
- Tomáš Klunda
- Institute of Chemistry
- Center for Glycomics
- Slovak Academy of Sciences
- SK-845 38 Bratislava
- Slovakia
| | - Michal Hricovíni
- Institute of Chemistry
- Center for Glycomics
- Slovak Academy of Sciences
- SK-845 38 Bratislava
- Slovakia
| | - Sergej Šesták
- Institute of Chemistry
- Center for Glycomics
- Slovak Academy of Sciences
- SK-845 38 Bratislava
- Slovakia
| | - Juraj Kóňa
- Institute of Chemistry
- Center for Glycomics
- Slovak Academy of Sciences
- SK-845 38 Bratislava
- Slovakia
| | - Monika Poláková
- Institute of Chemistry
- Center for Glycomics
- Slovak Academy of Sciences
- SK-845 38 Bratislava
- Slovakia
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Shaffner J, Chen B, Malhotra DK, Dworkin LD, Gong R. Therapeutic Targeting of SGLT2: A New Era in the Treatment of Diabetes and Diabetic Kidney Disease. Front Endocrinol (Lausanne) 2021; 12:749010. [PMID: 34790170 PMCID: PMC8591164 DOI: 10.3389/fendo.2021.749010] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/14/2021] [Indexed: 12/20/2022] Open
Abstract
As the prevalence of diabetic kidney disease (DKD) continues to rise, so does the need for a novel therapeutic modality that can control and slow its progression to end-stage renal disease. The advent of sodium-glucose cotransporter-2 (SGLT2) inhibitors has provided a major advancement for the treatment of DKD. However, there still remains insufficient understanding of the mechanism of action and effectiveness of this drug, and as a result, its use has been very limited. Burgeoning evidence suggests that the SGLT2 inhibitors possess renal protective activities that are able to lower glycemic levels, improve blood pressure/hemodynamics, cause bodyweight loss, mitigate oxidative stress, exert anti-inflammatory and anti-fibrotic effects, reduce urinary albumin excretion, lower uric acid levels, diminish the activity of intrarenal renin-angiotensin-aldosterone system, and reduce natriuretic peptide levels. SGLT2 inhibitors have been shown to be safe and beneficial for use in patients with a GFR ≥30mL/min/1.73m2, associated with a constellation of signs of metabolic reprogramming, including enhanced ketogenesis, which may be responsible for the correction of metabolic reprogramming that underlies DKD. This article aims to provide a comprehensive overview and better understanding of the SGLT2 inhibitor and its benefits as it pertains to renal pathophysiology. It summarizes our recent understanding on the mechanisms of action of SGLT2 inhibitors, discusses the effects of SGLT2 inhibitors on diabetes and DKD, and presents future research directions and therapeutic potential.
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Soták M, Casselbrant A, Rath E, Zietek T, Strömstedt M, Adingupu DD, Karlsson D, Fritsch Fredin M, Ergang P, Pácha J, Batorsky A, Alpers CE, Börgeson E, Hansen PBL, Ericsson A, Björnson Granqvist A, Wallenius V, Fändriks L, Unwin RJ. Intestinal sodium/glucose cotransporter 3 expression is epithelial and downregulated in obesity. Life Sci 2020; 267:118974. [PMID: 33385407 DOI: 10.1016/j.lfs.2020.118974] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 12/11/2020] [Accepted: 12/20/2020] [Indexed: 12/12/2022]
Abstract
AIM We aimed to determine whether the sodium/glucose cotransporter family member SGLT3, a proposed glucose sensor, is expressed in the intestine and/or kidney, and if its expression is altered in mouse models of obesity and in humans before and after weight-loss surgery. MAIN METHODS We used in-situ hybridization and quantitative PCR to determine whether the Sglt3 isoforms 3a and 3b were expressed in the intestine and kidney of C57, leptin-deficient ob/ob, and diabetic BTBR ob/ob mice. Western blotting and immunohistochemistry were also used to assess SGLT3 protein levels in jejunal biopsies from obese patients before and after weight-loss Roux-en-Y gastric bypass surgery (RYGB), and in lean healthy controls. KEY FINDINGS Sglt3a/3b mRNA was detected in the small intestine (duodenum, jejunum and ileum), but not in the large intestine or kidneys of mice. Both isoforms were detected in epithelial cells (confirmed using intestinal organoids). Expression of Sglt3a/3b mRNA in duodenum and jejunum was significantly lower in ob/ob and BTBR ob/ob mice than in normal-weight littermates. Jejunal SGLT3 protein levels in aged obese patients before RYGB were lower than in lean individuals, but substantially upregulated 6 months post-RYGB. SIGNIFICANCE Our study shows that Sglt3a/3b is expressed primarily in epithelial cells of the small intestine in mice. Furthermore, we observed an association between intestinal mRNA Sglt3a/3b expression and obesity in mice, and between jejunal SGLT3 protein levels and obesity in humans. Further studies are required to determine the possible role of SGLT3 in obesity.
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Affiliation(s)
- Matúš Soták
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; Department of Molecular and Clinical Medicine, Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Sweden.
| | - Anna Casselbrant
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Eva Rath
- Chair of Nutrition and Immunology, Technische Universität München, Freising, Germany
| | - Tamara Zietek
- Department of Nutritional Physiology, Technische Universität München, Freising, Germany
| | - Maria Strömstedt
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Damilola D Adingupu
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Daniel Karlsson
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Maria Fritsch Fredin
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Peter Ergang
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Jiří Pácha
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Anna Batorsky
- Department of Pathology, University of Washington School of Medicine, Seattle, USA
| | - Charles E Alpers
- Department of Pathology, University of Washington School of Medicine, Seattle, USA
| | - Emma Börgeson
- Department of Molecular and Clinical Medicine, Wallenberg Laboratory, Institute of Medicine, University of Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Sweden; Department of Clinical Physiology, Sahlgrenska University Hospital, Sweden
| | - Pernille B L Hansen
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Sweden
| | - Anette Ericsson
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Anna Björnson Granqvist
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden
| | - Ville Wallenius
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Lars Fändriks
- Department of Surgery, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - Robert J Unwin
- Bioscience, Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Gothenburg, Sweden; Department of Renal Medicine, Division of Medicine, University College London, UK
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12
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Elferink H, Bruekers JPJ, Veeneman GH, Boltje TJ. A comprehensive overview of substrate specificity of glycoside hydrolases and transporters in the small intestine : "A gut feeling". Cell Mol Life Sci 2020; 77:4799-4826. [PMID: 32506169 PMCID: PMC7658089 DOI: 10.1007/s00018-020-03564-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 05/21/2020] [Accepted: 05/25/2020] [Indexed: 02/07/2023]
Abstract
The human body is able to process and transport a complex variety of carbohydrates, unlocking their nutritional value as energy source or as important building block. The endogenous glycosyl hydrolases (glycosidases) and glycosyl transporter proteins located in the enterocytes of the small intestine play a crucial role in this process and digest and/or transport nutritional sugars based on their structural features. It is for these reasons that glycosidases and glycosyl transporters are interesting therapeutic targets to combat sugar related diseases (such as diabetes) or to improve drug delivery. In this review we provide a detailed overview focused on the molecular structure of the substrates involved as a solid base to start from and to fuel research in the area of therapeutics and diagnostics.
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Affiliation(s)
- Hidde Elferink
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525, Nijmegen, The Netherlands
| | - Jeroen P J Bruekers
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525, Nijmegen, The Netherlands
| | | | - Thomas J Boltje
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525, Nijmegen, The Netherlands.
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13
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Glucose transporters in brain in health and disease. Pflugers Arch 2020; 472:1299-1343. [PMID: 32789766 PMCID: PMC7462931 DOI: 10.1007/s00424-020-02441-x] [Citation(s) in RCA: 213] [Impact Index Per Article: 53.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 07/20/2020] [Accepted: 07/24/2020] [Indexed: 12/15/2022]
Abstract
Energy demand of neurons in brain that is covered by glucose supply from the blood is ensured by glucose transporters in capillaries and brain cells. In brain, the facilitative diffusion glucose transporters GLUT1-6 and GLUT8, and the Na+-d-glucose cotransporters SGLT1 are expressed. The glucose transporters mediate uptake of d-glucose across the blood-brain barrier and delivery of d-glucose to astrocytes and neurons. They are critically involved in regulatory adaptations to varying energy demands in response to differing neuronal activities and glucose supply. In this review, a comprehensive overview about verified and proposed roles of cerebral glucose transporters during health and diseases is presented. Our current knowledge is mainly based on experiments performed in rodents. First, the functional properties of human glucose transporters expressed in brain and their cerebral locations are described. Thereafter, proposed physiological functions of GLUT1, GLUT2, GLUT3, GLUT4, and SGLT1 for energy supply to neurons, glucose sensing, central regulation of glucohomeostasis, and feeding behavior are compiled, and their roles in learning and memory formation are discussed. In addition, diseases are described in which functional changes of cerebral glucose transporters are relevant. These are GLUT1 deficiency syndrome (GLUT1-SD), diabetes mellitus, Alzheimer’s disease (AD), stroke, and traumatic brain injury (TBI). GLUT1-SD is caused by defect mutations in GLUT1. Diabetes and AD are associated with changed expression of glucose transporters in brain, and transporter-related energy deficiency of neurons may contribute to pathogenesis of AD. Stroke and TBI are associated with changes of glucose transporter expression that influence clinical outcome.
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Gyimesi G, Pujol-Giménez J, Kanai Y, Hediger MA. Sodium-coupled glucose transport, the SLC5 family, and therapeutically relevant inhibitors: from molecular discovery to clinical application. Pflugers Arch 2020; 472:1177-1206. [PMID: 32767111 PMCID: PMC7462921 DOI: 10.1007/s00424-020-02433-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/24/2020] [Accepted: 07/02/2020] [Indexed: 02/06/2023]
Abstract
Sodium glucose transporters (SGLTs) belong to the mammalian solute carrier family SLC5. This family includes 12 different members in human that mediate the transport of sugars, vitamins, amino acids, or smaller organic ions such as choline. The SLC5 family belongs to the sodium symporter family (SSS), which encompasses transporters from all kingdoms of life. It furthermore shares similarity to the structural fold of the APC (amino acid-polyamine-organocation) transporter family. Three decades after the first molecular identification of the intestinal Na+-glucose cotransporter SGLT1 by expression cloning, many new discoveries have evolved, from mechanistic analysis to molecular genetics, structural biology, drug discovery, and clinical applications. All of these advances have greatly influenced physiology and medicine. While SGLT1 is essential for fast absorption of glucose and galactose in the intestine, the expression of SGLT2 is largely confined to the early part of the kidney proximal tubules, where it reabsorbs the bulk part of filtered glucose. SGLT2 has been successfully exploited by the pharmaceutical industry to develop effective new drugs for the treatment of diabetic patients. These SGLT2 inhibitors, termed gliflozins, also exhibit favorable nephroprotective effects and likely also cardioprotective effects. In addition, given the recent finding that SGLT2 is also expressed in tumors of pancreas and prostate and in glioblastoma, this opens the door to potential new therapeutic strategies for cancer treatment by specifically targeting SGLT2. Likewise, further discoveries related to the functional association of other SGLTs of the SLC5 family to human pathologies will open the door to potential new therapeutic strategies. We furthermore hope that the herein summarized information about the physiological roles of SGLTs and the therapeutic benefits of the gliflozins will be useful for our readers to better understand the molecular basis of the beneficial effects of these inhibitors, also in the context of the tubuloglomerular feedback (TGF), and the renin-angiotensin system (RAS). The detailed mechanisms underlying the clinical benefits of SGLT2 inhibition by gliflozins still warrant further investigation that may serve as a basis for future drug development.
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Affiliation(s)
- Gergely Gyimesi
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, and Department of Biomedical Research, Inselspital, University of Bern, Kinderklinik, Office D845, Freiburgstrasse 15, CH-3010, Bern, Switzerland
| | - Jonai Pujol-Giménez
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, and Department of Biomedical Research, Inselspital, University of Bern, Kinderklinik, Office D845, Freiburgstrasse 15, CH-3010, Bern, Switzerland
| | - Yoshikatsu Kanai
- Department of Bio-system Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Matthias A Hediger
- Membrane Transport Discovery Lab, Department of Nephrology and Hypertension, and Department of Biomedical Research, Inselspital, University of Bern, Kinderklinik, Office D845, Freiburgstrasse 15, CH-3010, Bern, Switzerland.
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15
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Endreffy I, Bjørklund G, Urbina MA, Chirumbolo S, Doşa MD, Dicső F. High Levels of Glycosaminoglycans in the Urines of Children with Attention-Deficit/Hyperactivity Disorder (ADHD). J Mol Neurosci 2020; 70:1018-1025. [PMID: 32128665 DOI: 10.1007/s12031-020-01496-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 02/05/2020] [Indexed: 01/02/2023]
Abstract
Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioral/neurodevelopmental disorder. Some early studies indicated that increased intake of added sugars might have a role in ADHD. In the present study, we tested this possibility by evaluating the urinary excretion of oligosaccharides and glycosaminoglycans (GAGs) in ADHD and control subjects. Forty ADHD subjects matched with 34 controls were enrolled in the study. The subjects underwent a standardized dietary regimen. The urine levels of oligosaccharides and GAGs were quantified biochemically, and their covariance and association were evaluated statistically. Fructose (21/40, 52.5%), maltose (26/40, 65%), galactose (30/40, 75%), and lactose (38/40, 95%) excretions were frequently found in the urine of ADHD subjects (p < 0.05), an excretion which does not occur normally. Furthermore, these subjects showed a pathologic tGAG (glycosaminoglycan) excretion (40/40, 100%). The present study supports the thesis that carbohydrate metabolism differs in ADHD subjects compared with control subjects.
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Affiliation(s)
- Ildikó Endreffy
- Department of Pediatrics, Josa András County Hospital, Nyíregyháza, Hungary
| | - Geir Bjørklund
- Council for Nutritional and Environmental Medicine, Toften 24, 8610, Mo i Rana, Norway.
| | - Mauricio A Urbina
- Departamento de Zoología, Facultad de Ciencias Naturales y Oceanográficas, Universidad de Concepción, Concepción, Chile
| | - Salvatore Chirumbolo
- Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
- CONEM Scientific Secretary, Verona, Italy
| | - Monica Daniela Doşa
- Department of Pharmacology, Faculty of Medicine, Ovidius University, Campus, 900470, Constanta, Romania.
| | - Ferenc Dicső
- Department of Pediatrics, Josa András County Hospital, Nyíregyháza, Hungary
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16
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Schäfer N, Friedrich M, Jørgensen ME, Kollert S, Koepsell H, Wischmeyer E, Lesch KP, Geiger D, Döring F. Functional analysis of a triplet deletion in the gene encoding the sodium glucose transporter 3, a potential risk factor for ADHD. PLoS One 2018; 13:e0205109. [PMID: 30286162 PMCID: PMC6171906 DOI: 10.1371/journal.pone.0205109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 09/19/2018] [Indexed: 12/19/2022] Open
Abstract
Sodium-glucose transporters (SGLT) belong to the solute carrier 5 family, which is characterized by sodium dependent transport of sugars and other solutes. In contrast, the human SGLT3 (hSGLT3) isoform, encoded by SLC5A4, acts as a glucose sensor that does not transport sugar but induces membrane depolarization by Na+ currents upon ligand binding. Whole-exome sequencing (WES) of several extended pedigrees with high density of attention-deficit/hyperactivity disorder (ADHD) identified a triplet ATG deletion in SLC5A4 leading to a single amino acid loss (ΔM500) in the hSGLT3 protein imperfectly co-segregating with the clinical phenotype of ADHD. Since mutations in homologous domains of hSGLT1 and hSGLT2 were found to affect intestinal and renal function, respectively, we analyzed the functional properties of hSGLT3[wt] and [ΔM500] by voltage clamp and current clamp recordings from cRNA-injected Xenopus laevis oocytes. The cation conductance of hSGLT3[wt] was activated by application of glucose or the specific agonist 1-desoxynojirimycin (DNJ) as revealed by inward currents in the voltage clamp configuration and cell depolarization in the current clamp mode. Almost no currents and changes in membrane potential were observed when glucose or DNJ were applied to hSGLT3[ΔM500]-injected oocytes, demonstrating a loss of function by this amino acid deletion in hSGLT3. To monitor membrane targeting of wt and mutant hSGLT3, fusion constructs with YFP were generated, heterologously expressed in Xenopus laevis oocytes and analyzed for membrane fluorescence by confocal microscopy. In comparison to hSGLT3[wt] the fluorescent signal of mutant [ΔM500] was reduced by 43% indicating that the mutant phenotype might mainly result from inaccurate membrane targeting. As revealed by homology modeling, residue M500 is located in TM11 suggesting that in addition to the core structure (TM1-TM10) of the transporter, the surrounding TMs are equally crucial for transport/sensor function. In conclusion, our findings indicate that the deletion [ΔM500] in hSGLT3 inhibits membrane targeting and thus largely disrupts glucose-induced sodium conductance, which may, in interaction with other ADHD risk-related gene variants, influence the risk for ADHD in deletion carriers.
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Affiliation(s)
- Nadine Schäfer
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, University of Würzburg, Würzburg, Germany
| | - Maximilian Friedrich
- Division of Molecular Psychiatry, Center of Mental Health, University Hospital of Würzburg, Würzburg, Germany
| | - Morten Egevang Jørgensen
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, University of Würzburg, Würzburg, Germany
| | - Sina Kollert
- Division of Molecular Psychiatry, Center of Mental Health, University Hospital of Würzburg, Würzburg, Germany
- Division of Molecular Electrophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Hermann Koepsell
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, University of Würzburg, Würzburg, Germany
| | - Erhard Wischmeyer
- Division of Molecular Electrophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- Department of Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health,University Hospital of Würzburg, Würzburg, Germany
| | - Klaus-Peter Lesch
- Division of Molecular Psychiatry, Center of Mental Health, University Hospital of Würzburg, Würzburg, Germany
- Laboratory of Psychiatric Neurobiology, Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow, Russia
- Department of Neuroscience, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Maastricht, The Netherlands
| | - Dietmar Geiger
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, University of Würzburg, Würzburg, Germany
| | - Frank Döring
- Division of Molecular Electrophysiology, Institute of Physiology, University of Würzburg, Würzburg, Germany
- Department of Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health,University Hospital of Würzburg, Würzburg, Germany
- * E-mail:
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17
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Assiri AM, El-Beeh ME, Amin AH, Ramadan MF. Ameliorative impact of Morus alba leaves’ aqueous extract against embryonic ophthalmic tissue malformation in streptozotocin-induced diabetic rats. Biomed Pharmacother 2017; 95:1072-1081. [DOI: 10.1016/j.biopha.2017.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 08/12/2017] [Accepted: 09/06/2017] [Indexed: 12/30/2022] Open
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18
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Wright EM, Ghezzi C, Loo DDF. Novel and Unexpected Functions of SGLTs. Physiology (Bethesda) 2017; 32:435-443. [PMID: 29021363 PMCID: PMC5817162 DOI: 10.1152/physiol.00021.2017] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 08/25/2017] [Accepted: 08/25/2017] [Indexed: 12/13/2022] Open
Abstract
It has been 30 years since the intestinal sodium glucose cotransporter SGLT1 was cloned, and, in the intervening years, there have been many advances that have influenced physiology and medicine. Among the first was that SGLT1 is the founding member of the human gene family SLC5, containing 11 diverse transporters and a glucose sensor. Equally surprising was that SGLTs are members of a structural family of cotransporters and exchangers in different gene families. This led to the conclusion that these proteins operate by a mechanism where transport involves the opening and closing of external and internal gates. The mechanism is shared by a wide variety of transporters in different structural families, e.g., the human facilitated glucose transporters (SLC2) in the huge major facilitator superfamily (MFS). Not surprising is the finding that mutations in Sglt genes cause the rare diseases glucose-galactose-malabsorption (GGM) and familial renal glucosuria (FRG). However, it was not envisaged that SGLT inhibitors would be used to treat diabetes mellitus, and these drugs may be able to treat cancer. Finally, in 2017, we have just learned that SGLT1 may be required to resist infection and to avoid recurrent pregnancy loss.
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Affiliation(s)
- Ernest M Wright
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Chiara Ghezzi
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California
| | - Donald D F Loo
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California
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19
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Chavan S, Gavale KS, Khan A, Joshi R, Kumbhar N, Chakravarty D, Dhavale DD. Iminosugars Spiro-Linked with Morpholine-Fused 1,2,3-Triazole: Synthesis, Conformational Analysis, Glycosidase Inhibitory Activity, Antifungal Assay, and Docking Studies. ACS OMEGA 2017; 2:7203-7218. [PMID: 30023541 PMCID: PMC6044920 DOI: 10.1021/acsomega.7b01299] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 10/13/2017] [Indexed: 05/21/2023]
Abstract
Synthesis of iminosugars 1, 2, 3a, and 4a and N-alkyl (ethyl, butyl, hexyl, octyl, decyl, and dodecyl) derivatives 3b-g and 4b-g spiro-linked with morpholine-fused 1,2,3-triazole is described. Conformation of the piperidine ring in each spiro-iminosugar was evaluated by 1H NMR spectroscopy, and conformational change in N-alkylated compounds 4b-g with respect to parent spiro-iminosugar 4a is supported by density functional theory calculations. Out of 16 new spiro-iminosugars, the spiro-iminosugars 3a (IC50 = 0.075 μM) and 4a (IC50 = 0.036 μM) were found to be more potent inhibitors of α-glucosidase than the marketed drug miglitol (IC50 = 0.100 μM). In addition, 3a (minimum inhibition concentration (MIC) = 0.85 μM) and 4a (MIC = 0.025 μM) showed more potent antifungal activity against Candida albicans than antifungal drug amphotericin b (MIC = 1.25 μM). In few cases, the N-alkyl derivatives showed increase of α-glucosidase inhibition and enhancement of antifungal activity compare to the respective parent iminosugar. The biological activities were further substantiated by molecular docking studies.
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Affiliation(s)
- Shrawan
R. Chavan
- Garware
Research Centre, Department of Chemistry, Department of Chemistry, Institute of Bio-informatics
and Biotechnology, and Central Instrumentation Facility, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind Road, Pune 411007, India
| | - Kishor S. Gavale
- Garware
Research Centre, Department of Chemistry, Department of Chemistry, Institute of Bio-informatics
and Biotechnology, and Central Instrumentation Facility, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind Road, Pune 411007, India
| | - Ayesha Khan
- Garware
Research Centre, Department of Chemistry, Department of Chemistry, Institute of Bio-informatics
and Biotechnology, and Central Instrumentation Facility, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind Road, Pune 411007, India
| | - Rakesh Joshi
- Garware
Research Centre, Department of Chemistry, Department of Chemistry, Institute of Bio-informatics
and Biotechnology, and Central Instrumentation Facility, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind Road, Pune 411007, India
| | - Navanath Kumbhar
- Garware
Research Centre, Department of Chemistry, Department of Chemistry, Institute of Bio-informatics
and Biotechnology, and Central Instrumentation Facility, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind Road, Pune 411007, India
| | - Debamitra Chakravarty
- Garware
Research Centre, Department of Chemistry, Department of Chemistry, Institute of Bio-informatics
and Biotechnology, and Central Instrumentation Facility, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind Road, Pune 411007, India
| | - Dilip D. Dhavale
- Garware
Research Centre, Department of Chemistry, Department of Chemistry, Institute of Bio-informatics
and Biotechnology, and Central Instrumentation Facility, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind Road, Pune 411007, India
- E-mail: ,
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20
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The Na+-D-glucose cotransporters SGLT1 and SGLT2 are targets for the treatment of diabetes and cancer. Pharmacol Ther 2017; 170:148-165. [DOI: 10.1016/j.pharmthera.2016.10.017] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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21
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Soták M, Marks J, Unwin RJ. Putative tissue location and function of the SLC5 family member SGLT3. Exp Physiol 2017; 102:5-13. [DOI: 10.1113/ep086042] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 11/08/2016] [Indexed: 01/29/2023]
Affiliation(s)
- Matúš Soták
- Cardiovascular and Metabolic Diseases; Innovative Medicines and Early Development Biotech Unit; AstraZeneca; Mölndal Sweden
| | - Joanne Marks
- Department of Neuroscience; Physiology and Pharmacology; University College London; London UK
| | - Robert J. Unwin
- Cardiovascular and Metabolic Diseases; Innovative Medicines and Early Development Biotech Unit; AstraZeneca; Mölndal Sweden
- Department of Neuroscience; Physiology and Pharmacology; University College London; London UK
- Department of Physiology and Neuroscience; University of Gothenburg; Gothenburg Sweden
- Centre for Nephrology; University College London; London UK
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22
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Affiliation(s)
- Saida Ortolano
- Group of Neonatal Pathology, Pediatrics and Rare Diseases, Instituto de Investigación Sanitaria Galicia Sur, Vigo, Spain
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23
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Kalam Azad MA, Wang F, Kim HR. Identification of a novel sugar compound from Korean pine seeds. Food Sci Biotechnol 2015. [DOI: 10.1007/s10068-015-0265-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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24
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Raja M, Kinne RK. Identification of phlorizin binding domains in sodium-glucose cotransporter family: SGLT1 as a unique model system. Biochimie 2015; 115:187-93. [DOI: 10.1016/j.biochi.2015.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 06/08/2015] [Indexed: 11/29/2022]
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25
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Lee EY, Kaneko S, Jutabha P, Zhang X, Seino S, Jomori T, Anzai N, Miki T. Distinct action of the α-glucosidase inhibitor miglitol on SGLT3, enteroendocrine cells, and GLP1 secretion. J Endocrinol 2015; 224:205-14. [PMID: 25486965 PMCID: PMC4324305 DOI: 10.1530/joe-14-0555] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Oral ingestion of carbohydrate triggers glucagon-like peptide 1 (GLP1) secretion, but the molecular mechanism remains elusive. By measuring GLP1 concentrations in murine portal vein, we found that the ATP-sensitive K(+) (KATP) channel is not essential for glucose-induced GLP1 secretion from enteroendocrine L cells, while the sodium-glucose co-transporter 1 (SGLT1) is required, at least in the early phase (5 min) of secretion. By contrast, co-administration of the α-glucosidase inhibitor (α-GI) miglitol plus maltose evoked late-phase secretion in a glucose transporter 2-dependent manner. We found that GLP1 secretion induced by miglitol plus maltose was significantly higher than that by another α-GI, acarbose, plus maltose, despite the fact that acarbose inhibits maltase more potently than miglitol. As miglitol activates SGLT3, we compared the effects of miglitol on GLP1 secretion with those of acarbose, which failed to depolarize the Xenopus laevis oocytes expressing human SGLT3. Oral administration of miglitol activated duodenal enterochromaffin (EC) cells as assessed by immunostaining of phosphorylated calcium-calmodulin kinase 2 (phospho-CaMK2). In contrast, acarbose activated much fewer enteroendocrine cells, having only modest phospho-CaMK2 immunoreactivity. Single administration of miglitol triggered no GLP1 secretion, and GLP1 secretion by miglitol plus maltose was significantly attenuated by atropine pretreatment, suggesting regulation via vagal nerve. Thus, while α-GIs generally delay carbohydrate absorption and potentiate GLP1 secretion, miglitol also activates duodenal EC cells, possibly via SGLT3, and potentiates GLP1 secretion through the parasympathetic nervous system.
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Affiliation(s)
- Eun Young Lee
- Department of Medical PhysiologyGraduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, JapanDepartment of Molecular PharmacologyGraduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, JapanDepartment of Pharmacology and ToxicologyDokkyo Medical University School of Medicine, Tochigi 321-0293, JapanDivision of Molecular and Metabolic MedicineKobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, JapanDrug Development CenterSanwa Kagaku Kenkyusho Co., Ltd, 35 Higashisotobori-cho, Higashi-ku, Nagoya 461-8631, Japan
| | - Shuji Kaneko
- Department of Medical PhysiologyGraduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, JapanDepartment of Molecular PharmacologyGraduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, JapanDepartment of Pharmacology and ToxicologyDokkyo Medical University School of Medicine, Tochigi 321-0293, JapanDivision of Molecular and Metabolic MedicineKobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, JapanDrug Development CenterSanwa Kagaku Kenkyusho Co., Ltd, 35 Higashisotobori-cho, Higashi-ku, Nagoya 461-8631, Japan
| | - Promsuk Jutabha
- Department of Medical PhysiologyGraduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, JapanDepartment of Molecular PharmacologyGraduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, JapanDepartment of Pharmacology and ToxicologyDokkyo Medical University School of Medicine, Tochigi 321-0293, JapanDivision of Molecular and Metabolic MedicineKobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, JapanDrug Development CenterSanwa Kagaku Kenkyusho Co., Ltd, 35 Higashisotobori-cho, Higashi-ku, Nagoya 461-8631, Japan
| | - Xilin Zhang
- Department of Medical PhysiologyGraduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, JapanDepartment of Molecular PharmacologyGraduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, JapanDepartment of Pharmacology and ToxicologyDokkyo Medical University School of Medicine, Tochigi 321-0293, JapanDivision of Molecular and Metabolic MedicineKobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, JapanDrug Development CenterSanwa Kagaku Kenkyusho Co., Ltd, 35 Higashisotobori-cho, Higashi-ku, Nagoya 461-8631, Japan
| | - Susumu Seino
- Department of Medical PhysiologyGraduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, JapanDepartment of Molecular PharmacologyGraduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, JapanDepartment of Pharmacology and ToxicologyDokkyo Medical University School of Medicine, Tochigi 321-0293, JapanDivision of Molecular and Metabolic MedicineKobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, JapanDrug Development CenterSanwa Kagaku Kenkyusho Co., Ltd, 35 Higashisotobori-cho, Higashi-ku, Nagoya 461-8631, Japan
| | - Takahito Jomori
- Department of Medical PhysiologyGraduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, JapanDepartment of Molecular PharmacologyGraduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, JapanDepartment of Pharmacology and ToxicologyDokkyo Medical University School of Medicine, Tochigi 321-0293, JapanDivision of Molecular and Metabolic MedicineKobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, JapanDrug Development CenterSanwa Kagaku Kenkyusho Co., Ltd, 35 Higashisotobori-cho, Higashi-ku, Nagoya 461-8631, Japan
| | - Naohiko Anzai
- Department of Medical PhysiologyGraduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, JapanDepartment of Molecular PharmacologyGraduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, JapanDepartment of Pharmacology and ToxicologyDokkyo Medical University School of Medicine, Tochigi 321-0293, JapanDivision of Molecular and Metabolic MedicineKobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, JapanDrug Development CenterSanwa Kagaku Kenkyusho Co., Ltd, 35 Higashisotobori-cho, Higashi-ku, Nagoya 461-8631, Japan
| | - Takashi Miki
- Department of Medical PhysiologyGraduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, JapanDepartment of Molecular PharmacologyGraduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, JapanDepartment of Pharmacology and ToxicologyDokkyo Medical University School of Medicine, Tochigi 321-0293, JapanDivision of Molecular and Metabolic MedicineKobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe 650-0017, JapanDrug Development CenterSanwa Kagaku Kenkyusho Co., Ltd, 35 Higashisotobori-cho, Higashi-ku, Nagoya 461-8631, Japan
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Haas B, Eckstein N, Pfeifer V, Mayer P, Hass MDS. Efficacy, safety and regulatory status of SGLT2 inhibitors: focus on canagliflozin. Nutr Diabetes 2014; 4:e143. [PMID: 25365416 PMCID: PMC4259905 DOI: 10.1038/nutd.2014.40] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 09/16/2014] [Accepted: 09/24/2014] [Indexed: 02/06/2023] Open
Abstract
Prevalence of diabetes mellitus is inc6reasing, with a burden of 382 million patients worldwide at present (more than the entire US population). The International Diabetes Federation anticipates an increase up to 592 million patients by 2035. Another major problem arises from the fact that just 50% of patients with type 2 diabetes mellitus are at target glycaemic control with currently available medications. Therefore, a clear need for new therapies that aim to optimize glycaemic control becomes evident. Renal sodium-linked glucose transporter 2 inhibitors are new antidiabetic drugs with an insulin-independent mechanism of action. They pose one remarkable advantage compared with already established antidiabetics: increasing urinary glucose excretion without inducing hypoglycaemia, thereby promoting body weight reduction due to loss of ~300 kcal per day. This review focuses on canagliflozin, which was the first successful compound of this class to be approved by both the US Food and Drug Administration and the European Medicines Agency in 2013. Clinical trials showed promising results: enhancing glycaemic control was paralleled by reducing body weight and systolic and diastolic blood pressure. Nevertheless, some safety concerns remain, such as genital mycotic infections, urinary tract infections and cardiovascular risks in vulnerable patients, which will be closely monitored in several post-authorization safety studies.
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Affiliation(s)
- B Haas
- Federal Institute for Drugs and Medical Devices, Bonn, Germany
| | - N Eckstein
- Federal Institute for Drugs and Medical Devices, Bonn, Germany
- Applied Pharmacy, University of Applied Sciences Kaiserslautern, Campus Pirmasens, Carl-Schurz-Str. 10–16, Pirmasens, Germany
| | - V Pfeifer
- Federal Institute for Drugs and Medical Devices, Bonn, Germany
| | - P Mayer
- Federal Institute for Drugs and Medical Devices, Bonn, Germany
| | - M D S Hass
- Federal Institute for Drugs and Medical Devices, Bonn, Germany
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Yamazaki Y, Harada S, Tokuyama S. Sodium-glucose transporter type 3-mediated neuroprotective effect of acetylcholine suppresses the development of cerebral ischemic neuronal damage. Neuroscience 2014; 269:134-42. [DOI: 10.1016/j.neuroscience.2014.03.046] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 02/24/2014] [Accepted: 03/21/2014] [Indexed: 01/27/2023]
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Validation of an Ion Trap Tandem Mass Spectrometric Analysis of Mulberry 1-Deoxynojirimycin in Human Plasma: Application to Pharmacokinetic Studies. Biosci Biotechnol Biochem 2014; 72:2210-3. [DOI: 10.1271/bbb.80200] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Jeszka-Skowron M, Flaczyk E, Jeszka J, Krejpcio Z, Król E, Buchowski MS. Mulberry leaf extract intake reduces hyperglycaemia in streptozotocin (STZ)-induced diabetic rats fed high-fat diet. J Funct Foods 2014. [DOI: 10.1016/j.jff.2014.02.018] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Chemical profiles and hypoglycemic activities of mulberry leaf extracts vary with ethanol concentration. Food Sci Biotechnol 2013. [DOI: 10.1007/s10068-013-0235-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
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31
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Wright EM. Glucose transport families SLC5 and SLC50. Mol Aspects Med 2013; 34:183-96. [DOI: 10.1016/j.mam.2012.11.002] [Citation(s) in RCA: 141] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 10/04/2012] [Indexed: 01/15/2023]
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Kothinti RK, Blodgett AB, North PE, Roman RJ, Tabatabai NM. A novel SGLT is expressed in the human kidney. Eur J Pharmacol 2012; 690:77-83. [PMID: 22766068 DOI: 10.1016/j.ejphar.2012.06.033] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2012] [Revised: 06/15/2012] [Accepted: 06/20/2012] [Indexed: 01/12/2023]
Abstract
Selective inhibitors of sodium-glucose cotransporter 2 (SGLT2)-mediated reabsorption of glucose in the proximal tubule of the kidney are being developed for the treatment of diabetes. SGLT2 shares high degree of homology with SGLT3; however, very little is known about the expression and functional role of SGLT3 in the human kidney. Indeed, the SGLT2 inhibitors that are currently in clinical trials might affect the expression and/or the activity of SGLT3. Therefore, the present study examined the expression of SGLT3 mRNA and protein in human kidney and in a human proximal tubule HK-2 cell line. The results indicated that human SGLT3 (hSGLT3) message and protein are expressed both in vivo and in vitro. We also studied the activity of hSGLT3 protein following its over-expression in mammalian kidney-derived COS-7 cells and in HK-2 cells treated with the imino sugar deoxynojirimycin (DNJ), a potent agonist of hSGLT3. Over-expression of hSGLT3 in COS-7 cells increased intracellular sodium concentration by 3-fold without affecting glucose transport. Activation of hSGLT3 with DNJ (50μM) increased sodium uptake in HK-2 cells by 5.5 fold and this effect could be completely blocked with SGLT inhibitor phlorizin (50μM). These results suggest that SGLT3 is expressed in human proximal tubular cells where it serves as a novel sodium transporter. Up-regulation of the expression of SGLT3 in the proximal tubule in diabetic patients may contribute to the elevated sodium transport in this segment of the nephron that has been postulated to promote hyperfiltration and renal injury.
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Affiliation(s)
- Rajendra K Kothinti
- Medical College of Wisconsin, Division of Endocrinology, Metabolism and Clinical Nutrition, 8701 Watertown Plank Road, Milwaukee, WI 53226, United States
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Barcelona S, Menegaz D, Díez-Sampedro A. Mouse SGLT3a generates proton-activated currents but does not transport sugar. Am J Physiol Cell Physiol 2012; 302:C1073-82. [DOI: 10.1152/ajpcell.00436.2011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Sodium-glucose cotransporters (SGLTs) are secondary active transporters belonging to the SLC5 gene family. SGLT1, a well-characterized member of this family, electrogenically transports glucose and galactose. Human SGLT3 (hSGLT3), despite sharing a high amino acid identity with human SGLT1 (hSGLT1), does not transport sugar, although functions as a sugar sensor. In contrast to humans, two different genes in mice and rats code for two different SGLT3 proteins, SGLT3a and SGLT3b. We previously cloned and characterized mouse SGLT3b (mSGLT3b) and showed that, while it does transport sugar like SGLT1, it likely functions as a physiological sugar sensor like hSGLT3. In this study, we cloned mouse SGLT3a (mSGLT3a) and characterized it by expressing it in Xenopus laevis oocytes and performing electrophysiology and sugar transport assays. mSGLT3a did not transport sugar, and sugars did not induce currents at pH 7.4, though acidic pH induced inward currents that increased in the presence of sugar. Moreover, mutation of residue 457 from glutamate to glutamine resulted in a Na+-dependent transport of sugar that was inhibited by phlorizin. To corroborate our results in oocytes, we expressed and characterized mSGLT3a in mammalian cells and confirmed our findings. In addition, we cloned, expressed, and characterized rat SGLT3a in oocytes and found characteristics similar to mSGLT3a. In summary, acidic pH induces currents in mSGLT3a, and sugar-induced currents are increased at acidic pH, but wild-type SGLT3a does not transport sugar.
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Affiliation(s)
- Stephanie Barcelona
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida
| | - Danusa Menegaz
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida
| | - Ana Díez-Sampedro
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida
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Liang Y, Arakawa K, Ueta K, Matsushita Y, Kuriyama C, Martin T, Du F, Liu Y, Xu J, Conway B, Conway J, Polidori D, Ways K, Demarest K. Effect of canagliflozin on renal threshold for glucose, glycemia, and body weight in normal and diabetic animal models. PLoS One 2012; 7:e30555. [PMID: 22355316 PMCID: PMC3280264 DOI: 10.1371/journal.pone.0030555] [Citation(s) in RCA: 180] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 12/19/2011] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Canagliflozin is a sodium glucose co-transporter (SGLT) 2 inhibitor in clinical development for the treatment of type 2 diabetes mellitus (T2DM). METHODS (14)C-alpha-methylglucoside uptake in Chinese hamster ovary-K cells expressing human, rat, or mouse SGLT2 or SGLT1; (3)H-2-deoxy-d-glucose uptake in L6 myoblasts; and 2-electrode voltage clamp recording of oocytes expressing human SGLT3 were analyzed. Graded glucose infusions were performed to determine rate of urinary glucose excretion (UGE) at different blood glucose (BG) concentrations and the renal threshold for glucose excretion (RT(G)) in vehicle or canagliflozin-treated Zucker diabetic fatty (ZDF) rats. This study aimed to characterize the pharmacodynamic effects of canagliflozin in vitro and in preclinical models of T2DM and obesity. RESULTS Treatment with canagliflozin 1 mg/kg lowered RT(G) from 415±12 mg/dl to 94±10 mg/dl in ZDF rats while maintaining a threshold relationship between BG and UGE with virtually no UGE observed when BG was below RT(G). Canagliflozin dose-dependently decreased BG concentrations in db/db mice treated acutely. In ZDF rats treated for 4 weeks, canagliflozin decreased glycated hemoglobin (HbA1c) and improved measures of insulin secretion. In obese animal models, canagliflozin increased UGE and decreased BG, body weight gain, epididymal fat, liver weight, and the respiratory exchange ratio. CONCLUSIONS Canagliflozin lowered RT(G) and increased UGE, improved glycemic control and beta-cell function in rodent models of T2DM, and reduced body weight gain in rodent models of obesity.
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MESH Headings
- Animals
- Blood Glucose/metabolism
- Body Weight/drug effects
- CHO Cells
- Canagliflozin
- Cells, Cultured
- Cricetinae
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/pathology
- Glucose Tolerance Test
- Glucosides/therapeutic use
- Humans
- Hyperglycemia/drug therapy
- Hyperglycemia/metabolism
- Hyperglycemia/pathology
- Kidney/drug effects
- Kidney/physiopathology
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Obese
- Muscle, Skeletal/cytology
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Rats
- Rats, Zucker
- Sodium-Glucose Transport Proteins/genetics
- Sodium-Glucose Transport Proteins/metabolism
- Sodium-Glucose Transporter 1/genetics
- Sodium-Glucose Transporter 1/metabolism
- Sodium-Glucose Transporter 2/genetics
- Sodium-Glucose Transporter 2/metabolism
- Sodium-Glucose Transporter 2 Inhibitors
- Thiophenes/therapeutic use
- Weight Gain/drug effects
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Affiliation(s)
- Yin Liang
- Johnson & Johnson Pharmaceutical Research & Development, LLC, Spring House, Pennsylvania, United States of America.
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Sala-Rabanal M, Hirayama BA, Loo DDF, Chaptal V, Abramson J, Wright EM. Bridging the gap between structure and kinetics of human SGLT1. Am J Physiol Cell Physiol 2011; 302:C1293-305. [PMID: 22159082 DOI: 10.1152/ajpcell.00397.2011] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Na(+)-glucose cotransporter hSGLT1 is a member of a class of membrane proteins that harness Na(+) electrochemical gradients to drive uphill solute transport. Although hSGLT1 belongs to one gene family (SLC5), recent structural studies of bacterial Na(+) cotransporters have shown that Na(+) transporters in different gene families have the same structural fold. We have constructed homology models of hSGLT1 in two conformations, the inward-facing occluded (based on vSGLT) and the outward open conformations (based on Mhp1), mutated in turn each of the conserved gates and ligand binding residues, expressed the SGLT1 mutants in Xenopus oocytes, and determined the functional consequences using biophysical and biochemical assays. The results establish that mutating the ligand binding residues produces profound changes in the ligand affinity (the half-saturation concentration, K(0.5)); e.g., mutating sugar binding residues increases the glucose K(0.5) by up to three orders of magnitude. Mutation of the external gate residues increases the Na(+) to sugar transport stoichiometry, demonstrating that these residues are critical for efficient cotransport. The changes in phlorizin inhibition constant (K(i)) are proportional to the changes in sugar K(0.5), except in the case of F101C, where phlorizin K(i) increases by orders of magnitude without a change in glucose K(0.5). We conclude that glucose and phlorizin occupy the same binding site and that F101 is involved in binding to the phloretin group of the inhibitor. Substituted-cysteine accessibility methods show that the cysteine residues at the position of the gates and sugar binding site are largely accessible only to external hydrophilic methanethiosulfonate reagents in the presence of external Na(+), demonstrating that the external sugar (and phlorizin) binding vestibule is opened by the presence of external Na(+) and closes after the binding of sugar and phlorizin. Overall, the present results provide a bridge between kinetics and structural studies of cotransporters.
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Affiliation(s)
- Monica Sala-Rabanal
- Department of Physiology, The Geffen School of Medicine at University of California, Los Angeles, California 90095-1751, USA
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Hummel CS, Lu C, Liu J, Ghezzi C, Hirayama BA, Loo DDF, Kepe V, Barrio JR, Wright EM. Structural selectivity of human SGLT inhibitors. Am J Physiol Cell Physiol 2011; 302:C373-82. [PMID: 21940664 DOI: 10.1152/ajpcell.00328.2011] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Human Na(+)-D-glucose cotransporter (hSGLT) inhibitors constitute the newest class of diabetes drugs, blocking up to 50% of renal glucose reabsorption in vivo. These drugs have potential for widespread use in the diabetes epidemic, but how they work at a molecular level is poorly understood. Here, we use electrophysiological methods to assess how they block Na(+)-D-glucose cotransporter SGLT1 and SGLT2 expressed in human embryonic kidney 293T (HEK-293T) cells and compared them to the classic SGLT inhibitor phlorizin. Dapagliflozin [(1S)-1,5,5-anhydro-1-C-{4-chloro-3-[(4-ethoxyphenyl)methyl]phenyl}-D-glucitol], two structural analogs, and the aglycones of phlorizin and dapagliflozin were investigated in detail. Dapagliflozin and fluoro-dapagliflozin [(1S)-1,5-anhydro-1-C-{4-chloro-3-[(4-ethoxyphenyl)methyl]phenyl}-4-F-4-deoxy-D-glucitol] blocked glucose transport and glucose-coupled currents with ≈100-fold specificity for hSGLT2 (K(i) = 6 nM) over hSGLT1 (K(i) = 400 nM). As galactose is a poor substrate for SGLT2, it was surprising that galacto-dapagliflozin [(1S)-1,5-anhydro-1-C-{4-chloro-3-[(4-ethoxyphenyl)methyl]phenyl}-D-galactitol] was a selective inhibitor of hSGLT2, but was less potent than dapagliflozin for both transporters (hSGLT2 K(i) = 25 nM, hSGLT1 K(i) = 25,000 nM). Phlorizin and galacto-dapagliflozin rapidly dissociated from SGLT2 [half-time off rate (t(1/2,Off)) ≈ 20-30 s], while dapagliflozin and fluoro-dapagliflozin dissociated from hSGLT2 at a rate 10-fold slower (t(1/2,Off) ≥ 180 s). Phlorizin was unable to exchange with dapagliflozin bound to hSGLT2. In contrast, dapagliflozin, fluoro-dapagliflozin, and galacto-dapagliflozin dissociated quickly from hSGLT1 (t(1/2,Off) = 1-2 s), and phlorizin readily exchanged with dapagliflozin bound to hSGLT1. The aglycones of phlorizin and dapagliflozin were poor inhibitors of both hSGLT2 and hSGLT1 with K(i) values > 100 μM. These results show that inhibitor binding to SGLTs is composed of two synergistic forces: sugar binding to the glucose site, which is not rigid, and so different sugars will change the orientation of the aglycone in the access vestibule; and the binding of the aglycone affects the binding affinity of the entire inhibitor. Therefore, the pharmacophore must include variations in both the structure of the sugar and the aglycone.
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Affiliation(s)
- Charles S Hummel
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-1751, USA
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Abstract
For the purpose of this article, iminosugars are polyhydroxylated secondary and tertiary amines in which the molecules resemble monosaccharide sugars in which the ring oxygen is replaced by the nitrogen. The bicyclic structures may biologically resemble disaccharides. Very few iminosugars have been available up to now for evaluation of their pharmaceutical applications. The early compounds were discovered and selected for study due to glycosidase inhibition, which is now known to not be necessary for pharmacological activity and may cause off-target effects. Glyset® and Zavesca®, derived from the glucosidase-inhibiting natural product 1-deoxynojirimycin, are the first two examples of iminosugar drugs. Since the discovery of this first generation, many new natural products have been identified with a wide range of biological activities but few are widely available. Among the biological properties of these compounds are good oral bioavailability and very specific immune modulatory and chaperoning activity. Although the natural products from plants and microorganisms can have good specificity, modifications of the template natural products have been very successful recently in producing bioactive compounds with good profiles. The field of iminosugars continues to open up exciting new opportunities for therapeutic agent discovery and offers many new tools for precisely modifying carbohydrate structures and modulating glycosidase activity in vivo. Current efforts are directed towards a greater range of structures and a wider range of biochemical targets.
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Vincent KM, Sharp JW, Raybould HE. Intestinal glucose-induced calcium-calmodulin kinase signaling in the gut-brain axis in awake rats. Neurogastroenterol Motil 2011; 23:e282-93. [PMID: 21303432 PMCID: PMC3101276 DOI: 10.1111/j.1365-2982.2011.01673.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Lumenal glucose initiates changes in gastrointestinal (GI) function, including inhibition of gastric emptying, stimulation of pancreatic exocrine and endocrine secretion, and intestinal fluid secretion. Glucose stimulates the release of GI hormones and 5-hydroxytryptamine (5-HT), and activates intrinsic and extrinsic neuronal pathways to initiate changes in GI function. The precise mechanisms involved in luminal glucose-sensing are not clear; studying gut endocrine cells is difficult due to their sparse and irregular localization within the epithelium. METHODS Here we show a technique to determine activation of gut epithelial cells and the gut-brain pathway in vivo in rats using immunohistochemical detection of the activated, phosphorylated, form of calcium-calmodulin kinase II (pCaMKII). KEY RESULTS Perfusion of the gut with glucose (60 mg) increased pCaMKII immunoreactivity in 5-HT-expressing enterochromaffin (EC) cells, cytokeratin-18 immunopositive brush cells, but not in enterocytes or cholecystokinin-expressing cells. Lumenal glucose increased pCaMKII in neurons in the myenteric plexus and nodose ganglion, nucleus of the solitary tract, dorsal motor nucleus of the vagus and the arcuate nucleus. pCaMKII expression in neurons, but not in EC cells, was significantly attenuated by pretreatment with the 5-HT(3) R antagonist ondansetron. Deoxynojirimycin, a selective agonist for the putative glucose sensor, sodium-glucose cotransporter-3 (SGLT-3), mimicked the effects of glucose with increased pCaMKII in ECs and neurons; galactose had no effect. CONCLUSIONS & INFERENCES The data suggest that native EC cells in situ respond to glucose, possibly via SGLT-3, to activate intrinsic and extrinsic neurons and thereby regulate GI function.
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Affiliation(s)
- K M Vincent
- Department of Anatomy, Physiology, and Cell Biology, University of California Davis School of Veterinary Medicine, Davis, CA 95616, USA
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Abstract
There are two classes of glucose transporters involved in glucose homeostasis in the body, the facilitated transporters or uniporters (GLUTs) and the active transporters or symporters (SGLTs). The energy for active glucose transport is provided by the sodium gradient across the cell membrane, the Na(+) glucose cotransport hypothesis first proposed in 1960 by Crane. Since the cloning of SGLT1 in 1987, there have been advances in the genetics, molecular biology, biochemistry, biophysics, and structure of SGLTs. There are 12 members of the human SGLT (SLC5) gene family, including cotransporters for sugars, anions, vitamins, and short-chain fatty acids. Here we give a personal review of these advances. The SGLTs belong to a structural class of membrane proteins from unrelated gene families of antiporters and Na(+) and H(+) symporters. This class shares a common atomic architecture and a common transport mechanism. SGLTs also function as water and urea channels, glucose sensors, and coupled-water and urea transporters. We also discuss the physiology and pathophysiology of SGLTs, e.g., glucose galactose malabsorption and familial renal glycosuria, and briefly report on targeting of SGLTs for new therapies for diabetes.
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Affiliation(s)
- Ernest M Wright
- Department of Physiology, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095-1751, USA.
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40
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Kwon HJ, Chung JY, Kim JY, Kwon O. Comparison of 1-deoxynojirimycin and aqueous mulberry leaf extract with emphasis on postprandial hypoglycemic effects: in vivo and in vitro studies. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2011; 59:3014-3019. [PMID: 21370820 DOI: 10.1021/jf103463f] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Carbohydrate digestion by α-glucosidase and subsequent glucose uptake at the brush border are critical for postprandial blood glucose control. Any specific inhibitors are useful as hyperglycemia modulating agents. In this study, it was postulated that an array of active components in mulberry leaf extract (MLE) may provide higher potency in inhibiting intestinal glucose absorption compared to the single component 1-deoxynojirimycin (DNJ), which is recognized as a promising inhibitor of intestinal glucose absorption. Both MLE and DNJ were active in inhibiting α-glucosidase. However, in Caco-2 cells, only MLE showed significant inhibition of 2-deoxyglucose uptake, whereas DNJ was ineffective. For glucose loading, co-administration of MLE resulted in potent inhibitions of glucose responses compared to those by DNJ in Sprague Dawley (SD) rats, but this was not found for maltose loading. These novel findings add evidence that the unabsorbed phytochemicals in MLE compete with glucose for intestinal glucose transporters, but DNJ itself does not. We also evaluated the timing of MLE consumption. By administering MLE for 30 min before glucose loading, the incremental area under the curve (IAUC) was significantly lowered in the rats, as compared to a simultaneously administered group. Similarly, cellular glucose uptake was significantly reduced in Caco-2 cells following pretreatment.
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Affiliation(s)
- Hye Jin Kwon
- Department of Nutritional Science and Food Management, Ewha Women's University, 11-1 Daehyeon-dong, Seodeamun-gu, Seoul 120-750, Korea
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41
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Csuk R, Prell E. Difluorotetrahydropyridothiazinone: a selective β-galactosidase inhibitor. Arch Pharm (Weinheim) 2011; 343:577-82. [PMID: 20925095 DOI: 10.1002/ardp.200900307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Selective difluorination, introducing a lactame moiety (instead of an amine) and a double bond in a trihydroxy-2-thiaquinolizidine derivative reverses the selectivity of the glycosidase inhibitor - a selective inhibitor for an α-glucosidase is altered into an excellent, competitive inhibitor for a β-galactosidase.
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Affiliation(s)
- René Csuk
- Martin-Luther-Universität Halle-Wittenberg, Bereich Organische Chemie, Halle (Saale), Germany.
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42
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Díez-Sampedro A, Barcelona S. Sugar binding residue affects apparent Na+ affinity and transport stoichiometry in mouse sodium/glucose cotransporter type 3B. J Biol Chem 2010; 286:7975-7982. [PMID: 21187287 DOI: 10.1074/jbc.m110.187880] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SGLT1 is a sodium/glucose cotransporter that moves two Na(+) ions with each glucose molecule per cycle. SGLT3 proteins belong to the same family and are described as glucose sensors rather than glucose transporters. Thus, human SGLT3 (hSGLT3) does not transport sugar, but extracellular glucose depolarizes the cell in which it is expressed. Mouse SGLT3b (mSGLT3b), although it transports sugar, has low apparent sugar affinity and partially uncoupled stoichiometry compared with SGLT1, suggesting that mSGLT3b is also a sugar sensor. The crystal structure of the Vibrio parahaemolyticus SGLT showed that residue Gln(428) interacts directly with the sugar. The corresponding amino acid in mammalian proteins, 457, is conserved in all SGLT1 proteins as glutamine. In SGLT3 proteins, glutamate is the most common residue at this position, although it is a glycine in mSGLT3b and a serine in rat SGLT3b. To test the contribution of this residue to the function of SGLT3 proteins, we constructed SGLT3b mutants that recapitulate residue 457 in SGLT1 and hSGLT3, glutamine and glutamate, respectively. The presence of glutamine at residue 457 increased the apparent Na(+) and sugar affinities, whereas glutamate decreased the apparent Na(+) affinity. Moreover, glutamate transported more cations per sugar molecule than the wild type protein. We propose a model where cations are released intracellularly without the release of sugar from an intermediate state. This model explains the uncoupled charge:sugar transport phenotype observed in wild type and G457E-mSGLT3b compared with SGLT1 and the sugar-activated cation transport without sugar transport that occurs in hSGLT3.
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Affiliation(s)
- Ana Díez-Sampedro
- From the Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida.
| | - Stephanie Barcelona
- From the Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida
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Prell E, Korb C, Kluge R, Ströhl D, Csuk R. Amplification of the Inhibitory Activity and Reversal of the Selectivity of Miglitol by C(2′)-Monofluorination. Arch Pharm (Weinheim) 2010; 343:583-9. [DOI: 10.1002/ardp.200900256] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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A single amino acid change converts the sugar sensor SGLT3 into a sugar transporter. PLoS One 2010; 5:e10241. [PMID: 20421923 PMCID: PMC2857651 DOI: 10.1371/journal.pone.0010241] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 03/29/2010] [Indexed: 01/08/2023] Open
Abstract
Background Sodium-glucose cotransporter proteins (SGLT) belong to the SLC5A family, characterized by the cotransport of Na+ with solute. SGLT1 is responsible for intestinal glucose absorption. Until recently the only role described for SGLT proteins was to transport sugar with Na+. However, human SGLT3 (hSGLT3) does not transport sugar but causes depolarization of the plasma membrane when expressed in Xenopus oocytes. For this reason SGLT3 was suggested to be a sugar sensor rather than a transporter. Despite 70% amino acid identity between hSGLT3 and hSGLT1, their sugar transport, apparent sugar affinities, and sugar specificity differ greatly. Residue 457 is important for the function of SGLT1 and mutation at this position in hSGLT1 causes glucose-galactose malabsorption. Moreover, the crystal structure of vibrio SGLT reveals that the residue corresponding to 457 interacts directly with the sugar molecule. We thus wondered if this residue could account for some of the functional differences between SGLT1 and SGLT3. Methodology/Principal Findings We mutated the glutamate at position 457 in hSGLT3 to glutamine, the amino acid present in all SGLT1 proteins, and characterized the mutant. Surprisingly, we found that E457Q-hSGLT3 transported sugar, had the same stoichiometry as SGLT1, and that the sugar specificity and apparent affinities for most sugars were similar to hSGLT1. We also show that SGLT3 functions as a sugar sensor in a living organism. We expressed hSGLT3 and E457Q-hSGLT3 in C. elegans sensory neurons and found that animals sensed glucose in an hSGLT3-dependent manner. Conclusions/Significance In summary, we demonstrate that hSGLT3 functions as a sugar sensor in vivo and that mutating a single amino acid converts this sugar sensor into a sugar transporter similar to SGLT1.
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Aljure O, Díez-Sampedro A. Functional characterization of mouse sodium/glucose transporter type 3b. Am J Physiol Cell Physiol 2010; 299:C58-65. [PMID: 20392930 DOI: 10.1152/ajpcell.00030.2010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Despite belonging to a family of sugar cotransporters, human sodium/glucose transporter type 3 (hSGLT3) does not transport sugar, but it depolarizes the cell in the presence of extracellular sugar, and thus it has been suggested to work as a sugar sensor. In the human genome there is one SGLT3 gene, yet in mouse there are two. In this study we cloned one of them, mouse SGLT3b (mSGLT3b) and characterized the protein. We found that mSGLT3b has low affinity for sugars, as does hSGLT3, but surprisingly, mSGLT3b transports sugar, although the sugar transport is not as tightly coupled to cations as in SGLT1. Moreover, the sugar specificity of mSGLT3b has characteristics reminiscent of both SGLT1 and hSGLT3: mSGLT3b does not respond to galactose, similar to hSGLT3, but neither does it respond to 1-deoxynojirimycin, unlike hSGLT3 but similar to SGLT1. mSGLT3b has low apparent affinities for sugar and Na(+) and, furthermore, displays pre-steady-state currents, which in SGLT1 report on conformational changes in the protein. Finally, phlorizin, the typical inhibitor of SGLT proteins, also inhibits mSGLT3b. In summary, although mSGLT3b has some characteristics that resemble SGLT1 and others that are similar to hSGLT3, its low sugar affinity and uncoupled sugar transport lead us to conclude that mSGLT3b likely functions as a physiological glucose sensor similar to hSGLT3.
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Affiliation(s)
- Oscar Aljure
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
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Reimann F. Molecular mechanisms underlying nutrient detection by incretin-secreting cells. Int Dairy J 2010; 20:236-242. [PMID: 20204054 PMCID: PMC2825293 DOI: 10.1016/j.idairyj.2009.11.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The hormones glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are secreted postprandially from intestinal K- and L-cells, respectively. As incretins, these hormones stimulate insulin secretion from the pancreatic β-cell, and have independently been implicated in the control of food intake and lipid metabolism. Whilst the enteroendocrine cells producing GIP and GLP-1 are therefore attractive targets for the treatment of diabetes and obesity, our understanding of their physiology is fairly limited. The mechanisms employed to sense the arrival of carbohydrate, fat and protein in the gut lumen have been investigated using organ perfusion techniques, primary epithelial cultures and cell line models. The recent development of mice with fluorescently labeled GIP or GLP-1-expressing cells is now enabling the use of single cell techniques to investigate stimulus-secretion coupling mechanisms. This review will focus on the current knowledge of the molecular machinery underlying nutrient sensing within K- and L-cells.
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Affiliation(s)
- Frank Reimann
- Cambridge Institute for Medical Research, Wellcome Trust/MRC Building, Addenbrooke's Hospital, Hills Road, Cambridge CB2 0XY, UK
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Park JM, Bong HY, Jeong HI, Kim YK, Kim JY, Kwon O. Postprandial hypoglycemic effect of mulberry leaf in Goto-Kakizaki rats and counterpart control Wistar rats. Nutr Res Pract 2009; 3:272-8. [PMID: 20098579 PMCID: PMC2809233 DOI: 10.4162/nrp.2009.3.4.272] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 11/24/2009] [Accepted: 12/15/2009] [Indexed: 11/29/2022] Open
Abstract
Postprandial hypoglycemic effect of mulberry leaf (Morus alba L.) was compared in two animal models: Goto-Kakizaki (GK) rats, a spontaneous non-obese animal model for type II diabetes, and their counterpart control Wistar rats. First, the effect of a single oral administration of mulberry leaf aqueous extract (MLE) on postprandial glucose responses was determined using maltose or glucose as substrate. With maltose-loading, MLE reduced peak responses of blood glucose significantly in both GK and Wistar rats (P < 0.05), supporting the inhibition of α-glucosidase by MLE in the small intestine. With glucose-loading, MLE also significantly reduced blood glucose concentrations, measured at 30 min, in both animal models (P < 0.01), proposing the inhibition of glucose transport by MLE. Next, dried mulberry leaf powder (MLP) was administered for 8 weeks by inclusion in the diet. By MLP administration, fasting blood glucose was significantly reduced at weeks 4 and 5 (P < 0.05), but then returned to values that were similar to those of the control at the end of experimental period in GK rats. Insulin, HOMA-IR, C-reactive protein, and triglycerides tended to be decreased by MLP treatment in GK rats. All other biochemical parameters were not changed by MLP administration in GK rats. Collectively, these findings support that MLE has significant postprandial hypoglycemic effect in both non-obese diabetic and healthy animals, which may be beneficial as food supplement to manage postprandial blood glucose. Inhibitions of glucose transport as well as α-glucosidase in the small intestine were suggested as possible mechanisms related with the postprandial hypoglycemic effect of MLE.
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Affiliation(s)
- Ji Min Park
- Department of Nutritional Science and Food Management, Ewha Woman's University, 11-1 Daehyeon-dong, Seodeamun-gu, Seoul 120-750, Korea
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Studies on reactivity of azidoamides, intermediates in the synthesis of tetrahydroxypipecolic acid derivatives. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.tetasy.2008.03.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Fairchild TJ. Protection of muscle membrane excitability during cycling in humans: a role for SGLT3? J Appl Physiol (1985) 2008; 104:315; author reply 316. [PMID: 18198291 DOI: 10.1152/japplphysiol.00793.2007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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50
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Yoshimizu M, Tajima Y, Matsuzawa F, Aikawa SI, Iwamoto K, Kobayashi T, Edmunds T, Fujishima K, Tsuji D, Itoh K, Ikekita M, Kawashima I, Sugawara K, Ohyanagi N, Suzuki T, Togawa T, Ohno K, Sakuraba H. Binding parameters and thermodynamics of the interaction of imino sugars with a recombinant human acid alpha-glucosidase (alglucosidase alfa): insight into the complex formation mechanism. Clin Chim Acta 2008; 391:68-73. [PMID: 18328816 DOI: 10.1016/j.cca.2008.02.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2007] [Revised: 01/22/2008] [Accepted: 02/07/2008] [Indexed: 11/26/2022]
Abstract
BACKGROUND Recently, enzyme enhancement therapy (EET) for Pompe disease involving imino sugars, which act as potential inhibitors of acid alpha-glucosidases in vitro, to improve the stability and/or transportation of mutant acid alpha-glucosidases in cells was studied and attracted interest. However, the mechanism underlying the molecular interaction between the imino sugars and the enzyme has not been clarified yet. METHODS We examined the inhibitory and binding effects of four imino sugars on a recombinant human acid alpha-glucosidase, alglucosidase alfa, by means of inhibition assaying and isothermal titration calorimetry (ITC). Furthermore, we built structural models of complexes of the catalytic domain of the enzyme with the imino sugars bound to its active site by homology modeling, and examined the molecular interaction between them. RESULTS All of the imino sugars examined exhibited a competitive inhibitory action against the enzyme, 1-deoxynojirimycin (DNJ) exhibiting the strongest action among them. ITC revealed that one compound molecule binds to one enzyme molecule and that DNJ most strongly binds to the enzyme among them. Structural analysis revealed that the active site of the enzyme is almost completely occupied by DNJ. CONCLUSION These biochemical and structural analyses increased our understanding of the molecular interaction between a human acid alpha-glucosidase and imino sugars.
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Affiliation(s)
- Michiru Yoshimizu
- Department of Clinical Genetics, The Tokyo Metropolitan Institute of Medical Science, Tokyo Metropolitan Organization for Medical Research, Tokyo, Japan
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