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Thorens B. Neuronal glucose sensing mechanisms and circuits in the control of insulin and glucagon secretion. Physiol Rev 2024; 104:1461-1486. [PMID: 38661565 DOI: 10.1152/physrev.00038.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 04/16/2024] [Accepted: 04/20/2024] [Indexed: 04/26/2024] Open
Abstract
Glucose homeostasis is mainly under the control of the pancreatic islet hormones insulin and glucagon, which, respectively, stimulate glucose uptake and utilization by liver, fat, and muscle and glucose production by the liver. The balance between the secretions of these hormones is under the control of blood glucose concentrations. Indeed, pancreatic islet β-cells and α-cells can sense variations in glycemia and respond by an appropriate secretory response. However, the secretory activity of these cells is also under multiple additional metabolic, hormonal, and neuronal signals that combine to ensure the perfect control of glycemia over a lifetime. The central nervous system (CNS), which has an almost absolute requirement for glucose as a source of metabolic energy and thus a vital interest in ensuring that glycemic levels never fall below ∼5 mM, is equipped with populations of neurons responsive to changes in glucose concentrations. These neurons control pancreatic islet cell secretion activity in multiple ways: through both branches of the autonomic nervous system, through the hypothalamic-pituitary-adrenal axis, and by secreting vasopressin (AVP) in the blood at the level of the posterior pituitary. Here, we present the autonomic innervation of the pancreatic islets; the mechanisms of neuron activation by a rise or a fall in glucose concentration; how current viral tracing, chemogenetic, and optogenetic techniques allow integration of specific glucose sensing neurons in defined neuronal circuits that control endocrine pancreas function; and, finally, how genetic screens in mice can untangle the diversity of the hypothalamic mechanisms controlling the response to hypoglycemia.
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Affiliation(s)
- Bernard Thorens
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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2
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Gautier-Stein A, Vily-Petit J, Rajas F, Mithieux G. Intestinal gluconeogenesis: A translator of nutritional information needed for glycemic and emotional balance. Biochimie 2024; 223:206-214. [PMID: 38040189 DOI: 10.1016/j.biochi.2023.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 11/17/2023] [Accepted: 11/23/2023] [Indexed: 12/03/2023]
Abstract
At the interface between the outside world and the self, the intestine is the first organ receiving nutritional information. One intestinal function, gluconeogenesis, is activated by various nutrients, particularly diets enriched in fiber or protein, and thus results in glucose production in the portal vein in the post-absorptive period. The detection of portal glucose induces a nervous signal controlling the activity of the central nuclei involved in the regulation of metabolism and emotional behavior. Induction of intestinal gluconeogenesis is necessary for the beneficial effects of fiber or protein-enriched diets on metabolism and emotional behavior. Through its ability to translate nutritional information from the diet to the brain's regulatory centers, intestinal gluconeogenesis plays an essential role in maintaining physiological balance.
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Affiliation(s)
- Amandine Gautier-Stein
- Universite Claude Bernard Lyon 1, NUDICE, UMR_S 1213, Villeurbanne, 69100, France; Institut National de la Sante et de la Recherche Medicale, NUDICE, UMR_S 1213, Lyon, 69372, France.
| | - Justine Vily-Petit
- Universite Claude Bernard Lyon 1, NUDICE, UMR_S 1213, Villeurbanne, 69100, France; Institut National de la Sante et de la Recherche Medicale, NUDICE, UMR_S 1213, Lyon, 69372, France
| | - Fabienne Rajas
- Universite Claude Bernard Lyon 1, NUDICE, UMR_S 1213, Villeurbanne, 69100, France; Institut National de la Sante et de la Recherche Medicale, NUDICE, UMR_S 1213, Lyon, 69372, France
| | - Gilles Mithieux
- Universite Claude Bernard Lyon 1, NUDICE, UMR_S 1213, Villeurbanne, 69100, France; Institut National de la Sante et de la Recherche Medicale, NUDICE, UMR_S 1213, Lyon, 69372, France
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3
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Daida T, Shin BC, Cepeda C, Devaskar SU. Neurodevelopment Is Dependent on Maternal Diet: Placenta and Brain Glucose Transporters GLUT1 and GLUT3. Nutrients 2024; 16:2363. [PMID: 39064806 PMCID: PMC11279700 DOI: 10.3390/nu16142363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 07/09/2024] [Accepted: 07/19/2024] [Indexed: 07/28/2024] Open
Abstract
Glucose is the primary energy source for most mammalian cells and its transport is affected by a family of facilitative glucose transporters (GLUTs) encoded by the SLC2 gene. GLUT1 and GLUT3, highly expressed isoforms in the blood-brain barrier and neuronal membranes, respectively, are associated with multiple neurodevelopmental disorders including epilepsy, dyslexia, ADHD, and autism spectrum disorder (ASD). Dietary therapies, such as the ketogenic diet, are widely accepted treatments for patients with the GLUT1 deficiency syndrome, while ameliorating certain symptoms associated with GLUT3 deficiency in animal models. A ketogenic diet, high-fat diet, and calorie/energy restriction during prenatal and postnatal stages can also alter the placental and brain GLUTs expression with long-term consequences on neurobehavior. This review focuses primarily on the role of diet/energy perturbations upon GLUT isoform-mediated emergence of neurodevelopmental and neurodegenerative disorders.
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Affiliation(s)
- Tomoko Daida
- Department of Pediatrics, Division of Neonatology and Developmental Biology and Neonatal Research Center, at the UCLA Children’s Discovery and Innovation Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; (T.D.); (B.-C.S.)
| | - Bo-Chul Shin
- Department of Pediatrics, Division of Neonatology and Developmental Biology and Neonatal Research Center, at the UCLA Children’s Discovery and Innovation Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; (T.D.); (B.-C.S.)
| | - Carlos Cepeda
- Intellectual and Developmental Disabilities Research Center and Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Sherin U. Devaskar
- Department of Pediatrics, Division of Neonatology and Developmental Biology and Neonatal Research Center, at the UCLA Children’s Discovery and Innovation Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; (T.D.); (B.-C.S.)
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4
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Watabe E, Kawanabe A, Kamitori K, Ichihara S, Fujiwara Y. Sugar binding of sodium-glucose cotransporters analyzed by voltage-clamp fluorometry. J Biol Chem 2024; 300:107215. [PMID: 38522518 PMCID: PMC11061222 DOI: 10.1016/j.jbc.2024.107215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 02/19/2024] [Accepted: 03/18/2024] [Indexed: 03/26/2024] Open
Abstract
Sugar absorption is crucial for life and relies on glucose transporters, including sodium-glucose cotransporters (SGLTs). Although the structure of SGLTs has been resolved, the substrate selectivity of SGLTs across diverse isoforms has not been determined owing to the complex substrate-recognition processes and limited analysis methods. Therefore, this study used voltage-clamp fluorometry (VCF) to explore the substrate-binding affinities of human SGLT1 in Xenopus oocytes. VCF analysis revealed high-affinity binding of D-glucose and D-galactose, which are known transported substrates. D-fructose, which is not a transported substrate, also bound to SGLT1, suggesting potential recognition despite the lack of transport activity. VCF analysis using the T287N mutant of the substrate-binding pocket, which has reduced D-glucose transport capacity, showed that its D-galactose-binding affinity exceeded its D-glucose-binding affinity. This suggests that the change in the VCF signal was due to substrate binding to the binding pocket. Both D-fructose and L-sorbose showed similar binding affinities, indicating that SGLT1 preferentially binds to pyranose-form sugars, including D-fructopyranose. Electrophysiological analysis confirmed that D-fructose binding did not affect the SGLT1 transport function. The significance of the VCF assay lies in its ability to measure sugar-protein interactions in living cells, thereby bridging the gap between structural analyses and functional characterizations of sugar transporters. Our findings also provide insights into SGLT substrate selectivity and the potential for developing medicines with reduced side effects by targeting non-glucose sugars with low bioreactivity.
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Affiliation(s)
- Erika Watabe
- Laboratory of Molecular Physiology & Biophysics, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa, Japan
| | - Akira Kawanabe
- Laboratory of Molecular Physiology & Biophysics, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa, Japan
| | - Kazuyo Kamitori
- Laboratory of Molecular Physiology & Biophysics, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa, Japan; International Institute of Rare Sugar Research and Education, Kagawa University, Miki-cho, Kagawa, Japan
| | - Satoko Ichihara
- Laboratory of Molecular Physiology & Biophysics, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa, Japan
| | - Yuichiro Fujiwara
- Laboratory of Molecular Physiology & Biophysics, Faculty of Medicine, Kagawa University, Miki-cho, Kagawa, Japan; International Institute of Rare Sugar Research and Education, Kagawa University, Miki-cho, Kagawa, Japan; Laboratory of Physiology and Biophysics, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima City, Hiroshima, Japan.
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5
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Mizutani K, Yoshida Y, Nakanishi E, Miyata Y, Tokumoto S, Fuse H, Gusev O, Kikuta S, Kikawada T. A sodium-dependent trehalose transporter contributes to anhydrobiosis in insect cell line, Pv11. Proc Natl Acad Sci U S A 2024; 121:e2317254121. [PMID: 38551840 PMCID: PMC10998604 DOI: 10.1073/pnas.2317254121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 02/13/2024] [Indexed: 04/02/2024] Open
Abstract
Pv11 is the only animal cell line that, when preconditioned with a high concentration of trehalose, can be preserved in the dry state at room temperature for more than one year while retaining the ability to resume proliferation. This extreme desiccation tolerance is referred to as anhydrobiosis. Here, we identified a transporter that contributes to the recovery of Pv11 cells from anhydrobiosis. In general, the solute carrier 5 (SLC5)-type secondary active transporters cotransport Na+ and carbohydrates including glucose. The heterologous expression systems showed that the transporter belonging to the SLC5 family, whose expression increases upon rehydration, exhibits Na+-dependent trehalose transport activity. Therefore, we named it STRT1 (sodium-ion trehalose transporter 1). We report an SLC5 family member that transports a naturally occurring disaccharide, such as trehalose. Knockout of the Strt1 gene significantly reduced the viability of Pv11 cells upon rehydration after desiccation. During rehydration, when intracellular trehalose is no longer needed, Strt1-knockout cells released the disaccharide more slowly than the parental cell line. During rehydration, Pv11 cells became roughly spherical due to osmotic pressure changes, but then returned to their original spindle shape after about 30 min. Strt1-knockout cells, however, required about 50 min to adopt their normal morphology. STRT1 probably regulates intracellular osmolality by releasing unwanted intracellular trehalose with Na+, thereby facilitating the recovery of normal cell morphology during rehydration. STRT1 likely improves the viability of dried Pv11 cells by rapidly alleviating the significant physical stresses that arise during rehydration.
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Affiliation(s)
- Kosuke Mizutani
- Department of Integrated Biosciences, Graduate School of Frontier Science, The University of Tokyo, Kashiwa, Chiba277-8562, Japan
| | - Yuki Yoshida
- Division of Biomaterial Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki305-8634, Japan
| | - Eita Nakanishi
- Department of Integrated Biosciences, Graduate School of Frontier Science, The University of Tokyo, Kashiwa, Chiba277-8562, Japan
| | - Yugo Miyata
- Department of Medical Chemistry, Medical Research Institute, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo113-8510, Japan
| | - Shoko Tokumoto
- Division of Biomaterial Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki305-8634, Japan
- Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Bunkyo-ku, Tokyo113-8421, Japan
| | - Hiroto Fuse
- Department of Integrated Biosciences, Graduate School of Frontier Science, The University of Tokyo, Kashiwa, Chiba277-8562, Japan
| | - Oleg Gusev
- Intractable Disease Research Center, Graduate School of Medicine, Juntendo University, Bunkyo-ku, Tokyo113-8421, Japan
| | - Shingo Kikuta
- Department of Regional and Comprehensive Agriculture, College of Agriculture, Ibaraki University, Ami, Ibaraki300-0393, Japan
| | - Takahiro Kikawada
- Department of Integrated Biosciences, Graduate School of Frontier Science, The University of Tokyo, Kashiwa, Chiba277-8562, Japan
- Division of Biomaterial Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Tsukuba, Ibaraki305-8634, Japan
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Witham MD, Granic A, Pearson E, Robinson SM, Sayer AA. Repurposing Drugs for Diabetes Mellitus as Potential Pharmacological Treatments for Sarcopenia - A Narrative Review. Drugs Aging 2023:10.1007/s40266-023-01042-4. [PMID: 37486575 PMCID: PMC10371965 DOI: 10.1007/s40266-023-01042-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/07/2023] [Indexed: 07/25/2023]
Abstract
Sarcopenia, the age-related loss of muscle strength and mass or quality, is a common condition with major adverse consequences. Although the pathophysiology is incompletely understood, there are common mechanisms between sarcopenia and the phenomenon of accelerated ageing seen in diabetes mellitus. Drugs currently used to treat type 2 diabetes mellitus may have mechanisms of action that are relevant to the prevention and treatment of sarcopenia, for those with type 2 diabetes and those without diabetes. This review summarises shared pathophysiology between sarcopenia and diabetes mellitus, including the effects of advanced glycation end products, mitochondrial dysfunction, chronic inflammation and changes to the insulin signalling pathway. Cellular and animal models have generated intriguing, albeit mixed, evidence that supports possible beneficial effects on skeletal muscle function for some classes of drugs used to treat diabetes, including metformin and SGLT2 inhibitors. Most human observational and intervention evidence for the effects of these drugs has been derived from populations with type 2 diabetes mellitus, and there is a need for intervention studies for older people with, and at risk of, sarcopenia to further investigate the balance of benefit and risk in these target populations. Not all diabetes treatments will be safe to use in those without diabetes because of variable side effects across classes. However, some agents [including glucagon-like peptide (GLP)-1 receptor agonists and SGLT2 inhibitors] have already demonstrated benefits in populations without diabetes, and it is these agents, along with metformin, that hold out the most promise for further investigation in sarcopenia.
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Affiliation(s)
- Miles D Witham
- AGE Research Group, Newcastle University Institute for Translational and Clinical Research, Newcastle Upon Tyne, UK.
- NIHR Newcastle Biomedical Research Centre, Newcastle University, Newcastle upon Tyne NHS Foundation Trust and Cumbria, Northumberland and Tyne and Wear NHS Foundation Trust, Newcastle Upon Tyne, UK.
| | - Antoneta Granic
- AGE Research Group, Newcastle University Institute for Translational and Clinical Research, Newcastle Upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle University, Newcastle upon Tyne NHS Foundation Trust and Cumbria, Northumberland and Tyne and Wear NHS Foundation Trust, Newcastle Upon Tyne, UK
| | - Ewan Pearson
- Division of Population Health and Genomics, Dundee Medical School, University of Dundee, Dundee, UK
| | - Sian M Robinson
- AGE Research Group, Newcastle University Institute for Translational and Clinical Research, Newcastle Upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle University, Newcastle upon Tyne NHS Foundation Trust and Cumbria, Northumberland and Tyne and Wear NHS Foundation Trust, Newcastle Upon Tyne, UK
| | - Avan A Sayer
- AGE Research Group, Newcastle University Institute for Translational and Clinical Research, Newcastle Upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle University, Newcastle upon Tyne NHS Foundation Trust and Cumbria, Northumberland and Tyne and Wear NHS Foundation Trust, Newcastle Upon Tyne, UK
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Taylor SI, Cherng HR, Yazdi ZS, Montasser ME, Whitlatch HB, Mitchell BD, Shuldiner AR, Streeten EA, Beitelshees AL. Pharmacogenetics of SGLT2 Inhibitors: Validation of a sex-agnostic pharmacodynamic biomarker. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.03.07.23286875. [PMID: 36945579 PMCID: PMC10029014 DOI: 10.1101/2023.03.07.23286875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
Aim SGLT2 inhibitors provide multiple benefits to patients with type 2 diabetes - including improved glycemic control and decreased risks of cardiorenal disease. Because drug responses vary among individuals, we initiated investigations to identify genetic variants associated with the magnitude of drug responses. Methods Canagliflozin (300 mg) was administered to 30 healthy volunteers. Several endpoints were measured to assess clinically relevant responses - including drug-induced increases in urinary excretion of glucose, sodium, and uric acid. Results This pilot study confirmed that canagliflozin (300 mg) triggered acute changes in mean levels of several biomarkers: fasting plasma glucose (-4.1 mg/dL; p=6x10), serum creatinine (+0.05 mg/dL; p=8×10 -4 ), and serum uric acid (-0.90 mg/dL; p=5×10 -10 ). The effects of sex on glucosuria depended upon how data were normalized. Whereas males' responses were ∼60% greater when data were normalized to body surface area, males and females exhibited similar responses when glucosuria was expressed as grams of urinary glucose per gram-creatinine. The magnitude of glucosuria was not significantly correlated with fasting plasma glucose, estimated GFR, or age in these healthy non-diabetic individuals with estimated GFR>60 mL/min/1.73m 2 . Conclusions Normalizing data relative to creatinine excretion will facilitate including data from males and females in a single analysis. Furthermore, because our ongoing pharmacogenomic study ( NCT02891954 ) is conducted in healthy individuals, this will facilitate detection of genetic associations with limited confounding by other factors such as age and renal function. Registration NCT02462421 ( clinicaltrials.gov ). Funding Research grants from the National Institute of Diabetes and Digestive and Kidney Diseases: R21DK105401, R01DK108942, T32DK098107, and P30DK072488.
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Affiliation(s)
- Simeon I. Taylor
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Hua-Ren Cherng
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Zhinous Shahidzadeh Yazdi
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - May E. Montasser
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Hilary B. Whitlatch
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Braxton D. Mitchell
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Alan R. Shuldiner
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Elizabeth A. Streeten
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
| | - Amber L. Beitelshees
- Department of Medicine, Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD 20201, USA
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8
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Li L, Shen FR, Cheng Q, Sun J, Li H, Sun HT, Cai X, Chen M, Yang B, Wang L, Xu L. SLC5A3 is important for cervical cancer cell growth. Int J Biol Sci 2023; 19:2787-2802. [PMID: 37324953 PMCID: PMC10266070 DOI: 10.7150/ijbs.84570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/16/2023] [Indexed: 06/17/2023] Open
Abstract
Novel molecular targets for cervical cancer must be identified. This study examined the role of SLC5A3, a myo-inositol transporter, in the pathogenesis of cervical cancer. Through boinformatics analysis, we showed that the SLC5A3 mRNA levels were upregulated in cervical cancer tissues. The upregulated SLC5A3 mRNA levels were negatively correlated with survival and progression-free interval. Genes co-expressed with SLC5A3 were enriched in multiple signaling cascades involved in cancer progression. In primary/established cervical cancer cells, SLC5A3 shRNA/knockout (KO) exerted growth-inhibitory effects and promoted cell death/apoptosis. Furthermore, SLC5A3 knockdown or KO downregulated myo-inositol levels, induced oxidative injury, and decreased Akt-mTOR activation in cervical cancer cells. In contrast, supplementation of myo-inositol or n-acetyl-L-cysteine or transduction of a constitutively active Akt1 construct mitigated SLC5A3 KO-induced cytotoxicity in cervical cancer cells. Lentiviral SLC5A3 overexpression construct transduction upregulated the cellular myo-inositol level and promoted Akt-mTOR activation, enhancing cervical cancer cell proliferation and migration. The binding of TonEBP to the SLC5A3 promoter was upregulated in cervical cancer. In vivo studies showed that intratumoral injection of SLC5A3 shRNA-expressing virus arrested cervical cancer xenograft growth in mice. SLC5A3 KO also inhibited pCCa-1 cervical cancer xenograft growth. The SLC5A3-depleted xenograft tissues exhibited myo-inositol downregulation, Akt-mTOR inactivation, and oxidative injury. Transduction of sh-TonEBP AAV construct downregulated SLC5A3 expression and inhibited pCCa-1 cervical cancer xenograft growth. Together, overexpressed SLC5A3 promotes growth of cervical cancer cells, representing as a novel therapeutic oncotarget for the devastating disease.
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Affiliation(s)
- Li Li
- Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai, China
| | - Fang-rong Shen
- Obstetrics and Gynecology Department, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Qunxian Cheng
- Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai, China
| | - Jing Sun
- Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai, China
| | - Hang Li
- Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai, China
| | - Hua-ting Sun
- Obstetrics and Gynecology Department, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xia Cai
- Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai, China
| | - Mengting Chen
- Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai, China
| | - Baohua Yang
- Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai, China
| | - Lifeng Wang
- Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai, China
| | - Ling Xu
- Department of Obstetrics and Gynecology, Minhang Hospital, Fudan University, Shanghai, China
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9
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Intestinal gluconeogenesis: metabolic benefits make sense in the light of evolution. Nat Rev Gastroenterol Hepatol 2023; 20:183-194. [PMID: 36470967 DOI: 10.1038/s41575-022-00707-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/27/2022] [Indexed: 03/02/2023]
Abstract
The intestine, like the liver and kidney, in various vertebrates and humans is able to carry out gluconeogenesis and release glucose into the blood. In the fed post-absorptive state, intestinal glucose is sensed by the gastrointestinal nervous system. The latter initiates a signal to the brain regions controlling energy homeostasis and stress-related behaviour. Intestinal gluconeogenesis (IGN) is activated by several complementary mechanisms, in particular nutritional situations (for example, when food is enriched in protein or fermentable fibre and after gastric bypass surgery in obesity). In these situations, IGN has several metabolic and behavioural benefits. As IGN is activated by nutrients capable of fuelling systemic gluconeogenesis, IGN could be a signal to the brain that food previously ingested is suitable for maintaining plasma glucose for a while. This process might account for the benefits observed. Finally, in this Perspective, we discuss how the benefits of IGN in fasting and fed states could explain why IGN emerged and was maintained in vertebrates by natural selection.
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10
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Hotait ZS, Lo Cascio JN, Choos END, Shepard BD. The sugar daddy: the role of the renal proximal tubule in glucose homeostasis. Am J Physiol Cell Physiol 2022; 323:C791-C803. [PMID: 35912988 PMCID: PMC9448277 DOI: 10.1152/ajpcell.00225.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/26/2022] [Accepted: 07/26/2022] [Indexed: 11/22/2022]
Abstract
Renal blood flow represents >20% of total cardiac output and with this comes the great responsibility of maintaining homeostasis through the intricate regulation of solute handling. Through the processes of filtration, reabsorption, and secretion, the kidneys ensure that solutes and other small molecules are either returned to circulation, catabolized within renal epithelial cells, or excreted through the process of urination. Although this occurs throughout the renal nephron, one segment is tasked with the bulk of solute reabsorption-the proximal tubule. Among others, the renal proximal tubule is entirely responsible for the reabsorption of glucose, a critical source of energy that fuels the body. In addition, it is the only other site of gluconeogenesis outside of the liver. When these processes go awry, pathophysiological conditions such as diabetes and acidosis result. In this review, we highlight the recent advances made in understanding these processes that occur within the renal proximal tubule. We focus on the physiological mechanisms at play regarding glucose reabsorption and glucose metabolism, emphasize the conditions that occur under diseased states, and explore the emerging class of therapeutics that are responsible for restoring homeostasis.
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Affiliation(s)
- Zahraa S Hotait
- Department of Human Science, Georgetown University, Washington, District of Columbia
| | - Julia N Lo Cascio
- Department of Human Science, Georgetown University, Washington, District of Columbia
| | - Elijah N D Choos
- Department of Human Science, Georgetown University, Washington, District of Columbia
| | - Blythe D Shepard
- Department of Human Science, Georgetown University, Washington, District of Columbia
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11
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The sodium/myo-inositol co-transporter SLC5A3 promotes non-small cell lung cancer cell growth. Cell Death Dis 2022; 13:569. [PMID: 35760803 PMCID: PMC9237060 DOI: 10.1038/s41419-022-05017-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 06/07/2022] [Accepted: 06/09/2022] [Indexed: 01/21/2023]
Abstract
Identification of novel molecular signaling targets for non-small cell lung cancer (NSCLC) is important. The present study examined expression, functions and possible underlying mechanisms of the sodium/myo-inositol co-transporter SLC5A3 in NSCLC. The Cancer Genome Atlas (TCGA) database and local NSCLC tissue results demonstrated that SLC5A3 expression in NSCLC tissues (including patient-derived primary NSCLC cells) was significantly higher than that in normal lung tissues and lung epithelial cells. In primary NSCLC cells and immortalized lines, SLC5A3 depletion, using small hairpin RNA (shRNA) and CRSIRP/Cas9 methods, robustly impeded cell proliferation and migration, simultaneously provoking cell cycle arrest and apoptosis. Conversely, ectopic overexpression of SLC5A3 further enhanced proliferation and migration in primary NSCLC cells. The intracellular myo-inositol contents and Akt-mTOR activation were largely inhibited by SLC5A3 silencing or knockout (KO), but were augmented following SLC5A3 overexpression in primary NSCLC cells. Significantly, SLC5A3 KO-induced anti-NSCLC cell activity was largely ameliorated by exogenously adding myo-inositol or by a constitutively-active Akt construct. By employing the patient-derived xenograft (PDX) model, we found that the growth of subcutaneous NSCLC xenografts in nude mice was largely inhibited by intratumoral injection SLC5A3 shRNA adeno-associated virus (AAV). SLC5A3 silencing, myo-inositol depletion, Akt-mTOR inactivation and apoptosis induction were detected in SLC5A3 shRNA virus-injected NSCLC xenograft tissues. Together, elevated SLC5A3 promotes NSCLC cell growth possibly by maintaining myo-inositol contents and promoting Akt-mTOR activation.
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12
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SGLT2 Inhibitors in Type 2 Diabetes Mellitus and Heart Failure-A Concise Review. J Clin Med 2022; 11:jcm11061470. [PMID: 35329796 PMCID: PMC8952302 DOI: 10.3390/jcm11061470] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 02/28/2022] [Accepted: 03/06/2022] [Indexed: 01/25/2023] Open
Abstract
The incidence of both diabetes mellitus type 2 and heart failure is rapidly growing, and the diseases often coexist. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are a new antidiabetic drug class that mediates epithelial glucose transport at the renal proximal tubules, inhibiting glucose absorption—resulting in glycosuria—and therefore improving glycemic control. Recent trials have proven that SGLT2i also improve cardiovascular and renal outcomes, including reduced cardiovascular mortality and fewer hospitalizations for heart failure. Reduced preload and afterload, improved vascular function, and changes in tissue sodium and calcium handling may also play a role. The expected paradigm shift in treatment strategies was reflected in the most recent 2021 guidelines published by the European Society of Cardiology, recommending dapagliflozin and empagliflozin as first-line treatment for heart failure patients with reduced ejection fraction. Moreover, the recent results of the EMPEROR-Preserved trial regarding empagliflozin give us hope that there is finally an effective treatment for patients with heart failure with preserved ejection fraction. This review aims to assess the efficacy and safety of these new anti-glycemic oral agents in the management of diabetic and heart failure patients.
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13
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Yang Y, Xu G. Update on Pathogenesis of Glomerular Hyperfiltration in Early Diabetic Kidney Disease. Front Endocrinol (Lausanne) 2022; 13:872918. [PMID: 35663316 PMCID: PMC9161673 DOI: 10.3389/fendo.2022.872918] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/11/2022] [Indexed: 11/13/2022] Open
Abstract
In the existing stages of diabetic kidney disease (DKD), the first stage of DKD is called the preclinical stage, characterized by glomerular hyperfiltration, an abnormally elevated glomerular filtration rate. Glomerular hyperfiltration is an independent risk factor for accelerated deterioration of renal function and progression of nephropathy, which is associated with a high risk for metabolic and cardiovascular disease. It is imperative to understand hyperfiltration and identify potential treatments to delay DKD progress. This paper summarizes the current mechanisms of hyperfiltration in early DKD. We pay close attention to the effect of glucose reabsorption mediated by sodium-glucose cotransporters and renal growth on hyperfiltration in DKD patients, as well as the mechanisms of nitric oxide and adenosine actions on renal afferent arterioles via tubuloglomerular feedback. Furthermore, we also focus on the contribution of the atrial natriuretic peptide, cyclooxygenase, renin-angiotensin-aldosterone system, and endothelin on hyperfiltration. Proposing potential treatments based on these mechanisms may offer new therapeutic opportunities to reduce the renal burden in this population.
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14
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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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15
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Sędzikowska A, Szablewski L. Human Glucose Transporters in Renal Glucose Homeostasis. Int J Mol Sci 2021; 22:13522. [PMID: 34948317 PMCID: PMC8708129 DOI: 10.3390/ijms222413522] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 12/26/2022] Open
Abstract
The kidney plays an important role in glucose homeostasis by releasing glucose into the blood stream to prevent hypoglycemia. It is also responsible for the filtration and subsequent reabsorption or excretion of glucose. As glucose is hydrophilic and soluble in water, it is unable to pass through the lipid bilayer on its own; therefore, transport takes place using carrier proteins localized to the plasma membrane. Both sodium-independent glucose transporters (GLUT proteins) and sodium-dependent glucose transporters (SGLT proteins) are expressed in kidney tissue, and mutations of the genes coding for these glucose transporters lead to renal disorders and diseases, including renal cancers. In addition, several diseases may disturb the expression and/or function of renal glucose transporters. The aim of this review is to describe the role of the kidney in glucose homeostasis and the contribution of glucose transporters in renal physiology and renal diseases.
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Affiliation(s)
| | - Leszek Szablewski
- Chair and Department of General Biology and Parasitology, Medical University of Warsaw, Chalubinskiego 5, 02-004 Warsaw, Poland;
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16
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Jang JH, Kim HK, Seo DW, Ki SY, Park S, Choi SH, Kim DH, Moon SJ, Jeong YT. Whole-Brain Mapping of the Expression Pattern of T1R2, a Subunit Specific to the Sweet Taste Receptor. Front Neuroanat 2021; 15:751839. [PMID: 34776881 PMCID: PMC8581048 DOI: 10.3389/fnana.2021.751839] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/04/2021] [Indexed: 12/29/2022] Open
Abstract
Chemosensory receptors are expressed primarily in sensory organs, but their expression elsewhere can permit ligand detection in other contexts that contribute to survival. The ability of sweet taste receptors to detect natural sugars, sugar alcohols, and artificial sweeteners suggests sweet taste receptors are involved in metabolic regulation in both peripheral organs and in the central nervous system. Our limited knowledge of sweet taste receptor expression in the brain, however, has made it difficult to assess their contribution to metabolic regulation. We, therefore, decided to profile the expression pattern of T1R2, a subunit specific to the sweet taste receptor complex, at the whole-brain level. Using T1r2-Cre knock-in mice, we visualized the overall distribution of Cre-labeled cells in the brain. T1r2-Cre is expressed not only in various populations of neurons, but also in glial populations in the circumventricular organs and in vascular structures in the cortex, thalamus, and striatum. Using immunohistochemistry, we found that T1r2 is expressed in hypothalamic neurons expressing neuropeptide Y and proopiomelanocortin in arcuate nucleus. It is also co-expressed with a canonical taste signaling molecule in perivascular cells of the median eminence. Our findings indicate that sweet taste receptors have unidentified functions in the brain and suggest that they may be a novel therapeutic target in the central nervous system.
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Affiliation(s)
- Jea Hwa Jang
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, South Korea.,Department of Pharmacology, Korea University College of Medicine, Seoul, South Korea
| | - Ha Kyeong Kim
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, South Korea.,Department of Pharmacology, Korea University College of Medicine, Seoul, South Korea
| | - Dong Woo Seo
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, South Korea.,Department of Pharmacology, Korea University College of Medicine, Seoul, South Korea
| | - Su Young Ki
- Department of Pharmacology, Korea University College of Medicine, Seoul, South Korea
| | - Soonhong Park
- Department of Oral Biology, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, South Korea
| | - Sang-Hyun Choi
- Department of Pharmacology, Korea University College of Medicine, Seoul, South Korea
| | - Dong-Hoon Kim
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, South Korea.,Department of Pharmacology, Korea University College of Medicine, Seoul, South Korea
| | - Seok Jun Moon
- Department of Oral Biology, BK21 PLUS Project, Yonsei University College of Dentistry, Seoul, South Korea
| | - Yong Taek Jeong
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, South Korea.,Department of Pharmacology, Korea University College of Medicine, Seoul, South Korea
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17
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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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18
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Neuro-immune-metabolism: The tripod system of homeostasis. Immunol Lett 2021; 240:77-97. [PMID: 34655659 DOI: 10.1016/j.imlet.2021.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 09/30/2021] [Accepted: 10/08/2021] [Indexed: 11/20/2022]
Abstract
Homeostatic regulation of cellular and molecular processes is essential for the efficient physiological functioning of body organs. It requires an intricate balance of several networks throughout the body, most notable being the nervous, immune and metabolic systems. Several studies have reported the interactions between neuro-immune, immune-metabolic and neuro-metabolic pathways. Current review aims to integrate the information and show that neuro, immune and metabolic systems form the triumvirate of homeostasis. It focuses on the cellular and molecular interactions occurring in the extremities and intestine, which are innervated by the peripheral nervous system and for the intestine in particular the enteric nervous system. While the interdependence of neuro-immune-metabolic pathways provides a fallback mechanism in case of disruption of homeostasis, in chronic pathologies of continued disequilibrium, the collapse of one system spreads to the other interacting networks as well. Current review illustrates this domino-effect using diabetes as the main example. Together, this review attempts to provide a holistic picture of the integrated network of neuro-immune-metabolism and attempts to broaden the outlook when devising a scientific study or a treatment strategy.
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19
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Pizzagalli MD, Bensimon A, Superti‐Furga G. A guide to plasma membrane solute carrier proteins. FEBS J 2021; 288:2784-2835. [PMID: 32810346 PMCID: PMC8246967 DOI: 10.1111/febs.15531] [Citation(s) in RCA: 181] [Impact Index Per Article: 60.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022]
Abstract
This review aims to serve as an introduction to the solute carrier proteins (SLC) superfamily of transporter proteins and their roles in human cells. The SLC superfamily currently includes 458 transport proteins in 65 families that carry a wide variety of substances across cellular membranes. While members of this superfamily are found throughout cellular organelles, this review focuses on transporters expressed at the plasma membrane. At the cell surface, SLC proteins may be viewed as gatekeepers of the cellular milieu, dynamically responding to different metabolic states. With altered metabolism being one of the hallmarks of cancer, we also briefly review the roles that surface SLC proteins play in the development and progression of cancer through their influence on regulating metabolism and environmental conditions.
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Affiliation(s)
- Mattia D. Pizzagalli
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Ariel Bensimon
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Giulio Superti‐Furga
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
- Center for Physiology and PharmacologyMedical University of ViennaAustria
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20
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Takeda K, Ono H, Ishikawa K, Ohno T, Kumagai J, Ochiai H, Matumoto A, Yokoh H, Maezawa Y, Yokote K. Central administration of sodium-glucose cotransporter-2 inhibitors increases food intake involving adenosine monophosphate-activated protein kinase phosphorylation in the lateral hypothalamus in healthy rats. BMJ Open Diabetes Res Care 2021; 9:9/1/e002104. [PMID: 33879516 PMCID: PMC8061802 DOI: 10.1136/bmjdrc-2020-002104] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 03/03/2021] [Accepted: 03/21/2021] [Indexed: 01/14/2023] Open
Abstract
INTRODUCTION Sodium glucose cotransporter-2 (SGLT2) inhibitors are widely used for diabetes treatment. Although SGLT2 inhibitors have been clinically observed to increase food intake, roles or even the presence of SGLT2 in the central nervous system (CNS) has not been established. We aimed to elucidate potential functions of SGLT2 in the CNS, and the effects of CNS-targeted SGLT2 inhibitors on food intake. RESEARCH DESIGN AND METHODS We administered three kinds of SGLT2 inhibitors, tofogliflozin, dapagliflozin, and empagliflozin, into the lateral ventricle (LV) in rats and evaluated their effects on food intake. We also evaluated the effects of tofogliflozin administration in the third (3V) and fourth ventricle (4V). Intraperitoneal administration of liraglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist known to suppress food intake, was combined with central tofogliflozin to elucidate whether GLP-1 signaling antagonizes the effect of central SGLT2 inhibitors on food intake. To elucidate potential molecular mechanisms mediating changes in feeding, hypothalamic areas associated with food intake regulation were harvested and analyzed after intracerebroventricular administration (ICV) of tofogliflozin. RESULTS Bolus ICV injection of tofogliflozin induced a robust increase in food intake starting at 1.5 hours postinjection, and lasting for 5 days. No effect was observed when the same dose of tofogliflozin was administered intraperitoneally. ICV dapagliflozin and empagliflozin significantly enhanced food intake, although the strength of these effects varied among drugs. Food intake was most markedly enhanced when tofogliflozin was infused into the LV. Fewer or no effects were observed with infusion into the 3V or 4V, respectively. Systemic administration of liraglutide suppressed the effect of ICV tofogliflozin on food intake. ICV tofogliflozin increased phosphorylation of AMPK and c-fos expression in the lateral hypothalamus. CONCLUSIONS SGLT2 inhibitors in the CNS increase food intake. SGLT2 activity in the CNS may regulate food intake through AMPK phosphorylation in the lateral hypothalamic area.
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Affiliation(s)
- Kenji Takeda
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Hiraku Ono
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Ko Ishikawa
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Tomohiro Ohno
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Jin Kumagai
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Hidetoshi Ochiai
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Ai Matumoto
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Hidetaka Yokoh
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Yoshiro Maezawa
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Koutaro Yokote
- Department of Endocrinology, Hematology, and Gerontology, Chiba University Graduate School of Medicine, Chiba, Japan
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21
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Lu VB, Gribble FM, Reimann F. Nutrient-Induced Cellular Mechanisms of Gut Hormone Secretion. Nutrients 2021; 13:nu13030883. [PMID: 33803183 PMCID: PMC8000029 DOI: 10.3390/nu13030883] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/27/2021] [Accepted: 03/05/2021] [Indexed: 02/06/2023] Open
Abstract
The gastrointestinal tract can assess the nutrient composition of ingested food. The nutrient-sensing mechanisms in specialised epithelial cells lining the gastrointestinal tract, the enteroendocrine cells, trigger the release of gut hormones that provide important local and central feedback signals to regulate nutrient utilisation and feeding behaviour. The evidence for nutrient-stimulated secretion of two of the most studied gut hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), along with the known cellular mechanisms in enteroendocrine cells recruited by nutrients, will be the focus of this review. The mechanisms involved range from electrogenic transporters, ion channel modulation and nutrient-activated G-protein coupled receptors that converge on the release machinery controlling hormone secretion. Elucidation of these mechanisms will provide much needed insight into postprandial physiology and identify tractable dietary approaches to potentially manage nutrition and satiety by altering the secreted gut hormone profile.
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22
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Hypothalamic detection of macronutrients via multiple gut-brain pathways. Cell Metab 2021; 33:676-687.e5. [PMID: 33450178 PMCID: PMC7933100 DOI: 10.1016/j.cmet.2020.12.018] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 10/30/2020] [Accepted: 12/23/2020] [Indexed: 12/24/2022]
Abstract
Food intake is tightly regulated by complex and coordinated gut-brain interactions. Nutrients rapidly modulate activity in key populations of hypothalamic neurons that regulate food intake, including hunger-sensitive agouti-related protein (AgRP)-expressing neurons. Because individual macronutrients engage specific receptors in the gut to communicate with the brain, we reasoned that macronutrients may utilize different pathways to reduce activity in AgRP neurons. Here, we revealed that AgRP neuron activity in hungry mice is inhibited by site-specific intestinal detection of different macronutrients. We showed that vagal gut-brain signaling is required for AgRP neuron inhibition by fat. In contrast, spinal gut-brain signaling relays the presence of intestinal glucose. Further, we identified glucose sensors in the intestine and hepatic portal vein that mediate glucose-dependent AgRP neuron inhibition. Therefore, distinct pathways are activated by individual macronutrients to inhibit AgRP neuron activity.
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23
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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: 22] [Impact Index Per Article: 7.3] [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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24
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Abstract
Energy balance is centrally regulated by the brain through several interacting neuronal systems involving external, peripheral, and central factors within the brain. The hypothalamus integrates these factors and is the key brain area in the regulation of energy balance. In this review, we will explain the structure of the hypothalamus and its role in the regulation of energy balance. An important part of energy balance regulation is the sensing of nutrient status and availability. This review will focus on the sensing of the two main sources of energy by the hypothalamus: glucose and fat. As many common health problems and chronic diseases can be traced back to a disrupted hypothalamic function, we will also discuss hypothalamic sensing of glucose and fats in these pathologies. Finally, we will summarize the current knowledge and discuss how this may be applied clinically and for future research perspectives.
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25
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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: 9] [Impact Index Per Article: 2.3] [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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26
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Alternative Splicing and Cleavage of GLUT8. Mol Cell Biol 2020; 41:MCB.00480-20. [PMID: 33077497 DOI: 10.1128/mcb.00480-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 10/01/2020] [Indexed: 11/20/2022] Open
Abstract
The GLUT (SLC2) family of membrane-associated transporters are described as glucose transporters. However, this family is divided into three classes and, though the regulated transporter activity of class I proteins is becoming better understood, class III protein functions continue to be obscure. We have cataloged the relative expression and splicing of SLC2 mRNA isomers in tumors and normal tissues, with a focus on breast tumors and cell lines. mRNA for the class III protein GLUT8 is the predominant SLC2 species expressed alongside GLUT1 in many tissues, but GLUT8 mRNA exists mostly as an untranslated splice form in tumors. We confirm that GLUT8 is not presented at the cell surface and does not transport glucose directly. However, we reveal a lysosome-dependent reaction that cleaves the GLUT8 protein and releases the carboxy-terminal peptide to a separate vesicle population. Given the localization of GLUT8 at a major metabolic hub (the late endosomal/lysosomal interface) and its regulated cleavage reaction, we evaluated TXNIP-mediated hexosamine homeostasis and speculate that GLUT8 may function as a sensory component of this reaction.
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Otto C, Friedrich A, Vrhovac Madunić I, Baumeier C, Schwenk RW, Karaica D, Germer CT, Schürmann A, Sabolić I, Koepsell H. Antidiabetic Effects of a Tripeptide That Decreases Abundance of Na +-d-glucose Cotransporter SGLT1 in the Brush-Border Membrane of the Small Intestine. ACS OMEGA 2020; 5:29127-29139. [PMID: 33225144 PMCID: PMC7675577 DOI: 10.1021/acsomega.0c03844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/16/2020] [Indexed: 05/08/2023]
Abstract
In enterocytes, protein RS1 (RSC1A1) mediates an increase of glucose absorption after ingestion of glucose-rich food via upregulation of Na+-d-glucose cotransporter SGLT1 in the brush-border membrane (BBM). Whereas RS1 decelerates the exocytotic pathway of vesicles containing SGLT1 at low glucose levels between meals, RS1-mediated deceleration is relieved after ingestion of glucose-rich food. Regulation of SGLT1 is mediated by RS1 domain RS1-Reg, in which Gln-Ser-Pro (QSP) is effective. In contrast to QSP and RS1-Reg, Gln-Glu-Pro (QEP) and RS1-Reg with a serine to glutamate exchange in the QSP motif downregulate the abundance of SGLT1 in the BBM at high intracellular glucose concentrations by about 50%. We investigated whether oral application of QEP improves diabetes in db/db mice and affects the induction of diabetes in New Zealand obese (NZO) mice under glucolipotoxic conditions. After 6-day administration of drinking water containing 5 mM QEP to db/db mice, fasting glucose was decreased, increase of blood glucose in the oral glucose tolerance test was blunted, and insulin sensitivity was increased. When QEP was added for several days to a high fat/high carbohydrate diet that induced diabetes in NZO mice, the increase of random plasma glucose was prevented, accompanied by lower plasma insulin levels. QEP is considered a lead compound for development of new antidiabetic drugs with more rapid cellular uptake. In contrast to SGLT1 inhibitors, QEP-based drugs may be applied in combination with insulin for the treatment of type 1 and type 2 diabetes, decreasing the required insulin amount, and thereby may reduce the risk of hypoglycemia.
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Affiliation(s)
- Christoph Otto
- Department
of General, Visceral, Transplantation, Vascular and Pediatric Surgery, University Hospital of Würzburg, 97080 Würzburg, Germany
| | - Alexandra Friedrich
- Institute
of Anatomy and Cell Biology, University
of Würzburg, 97070 Würzburg, Germany
| | - Ivana Vrhovac Madunić
- Molecular
Toxicology Unit, Institute for Medical Research
and Occupational Health, 10000 Zagreb, Croatia
| | - Christian Baumeier
- Department
of Experimental Diabetology, German Institute
of Human Nutrition, 14558 Potsdam-Rehbruecke, Germany
- German
Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Robert W. Schwenk
- Department
of Experimental Diabetology, German Institute
of Human Nutrition, 14558 Potsdam-Rehbruecke, Germany
- German
Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Dean Karaica
- Molecular
Toxicology Unit, Institute for Medical Research
and Occupational Health, 10000 Zagreb, Croatia
| | - Christoph-Thomas Germer
- Department
of General, Visceral, Transplantation, Vascular and Pediatric Surgery, University Hospital of Würzburg, 97080 Würzburg, Germany
| | - Annette Schürmann
- Department
of Experimental Diabetology, German Institute
of Human Nutrition, 14558 Potsdam-Rehbruecke, Germany
- German
Center for Diabetes Research (DZD), 85764 München-Neuherberg, Germany
| | - Ivan Sabolić
- Molecular
Toxicology Unit, Institute for Medical Research
and Occupational Health, 10000 Zagreb, Croatia
| | - Hermann Koepsell
- Institute
of Anatomy and Cell Biology, University
of Würzburg, 97070 Würzburg, Germany
- . Phone: +49-0151 23532479
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Chiba Y, Murakami R, Matsumoto K, Wakamatsu K, Nonaka W, Uemura N, Yanase K, Kamada M, Ueno M. Glucose, Fructose, and Urate Transporters in the Choroid Plexus Epithelium. Int J Mol Sci 2020; 21:E7230. [PMID: 33008107 PMCID: PMC7582461 DOI: 10.3390/ijms21197230] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 02/07/2023] Open
Abstract
The choroid plexus plays a central role in the regulation of the microenvironment of the central nervous system by secreting the majority of the cerebrospinal fluid and controlling its composition, despite that it only represents approximately 1% of the total brain weight. In addition to a variety of transporter and channel proteins for solutes and water, the choroid plexus epithelial cells are equipped with glucose, fructose, and urate transporters that are used as energy sources or antioxidative neuroprotective substrates. This review focuses on the recent advances in the understanding of the transporters of the SLC2A and SLC5A families (GLUT1, SGLT2, GLUT5, GLUT8, and GLUT9), as well as on the urate-transporting URAT1 and BCRP/ABCG2, which are expressed in choroid plexus epithelial cells. The glucose, fructose, and urate transporters repertoire in the choroid plexus epithelium share similar features with the renal proximal tubular epithelium, although some of these transporters exhibit inversely polarized submembrane localization. Since choroid plexus epithelial cells have high energy demands for proper functioning, a decline in the expression and function of these transporters can contribute to the process of age-associated brain impairment and pathophysiology of neurodegenerative diseases.
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Affiliation(s)
- Yoichi Chiba
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (Y.C.); (R.M.); (K.M.); (K.W.)
| | - Ryuta Murakami
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (Y.C.); (R.M.); (K.M.); (K.W.)
| | - Koichi Matsumoto
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (Y.C.); (R.M.); (K.M.); (K.W.)
| | - Keiji Wakamatsu
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (Y.C.); (R.M.); (K.M.); (K.W.)
| | - Wakako Nonaka
- Department of Supportive and Promotive Medicine of the Municipal Hospital, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan;
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan
| | - Naoya Uemura
- Department of Anesthesiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (N.U.); (K.Y.)
| | - Ken Yanase
- Department of Anesthesiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (N.U.); (K.Y.)
| | - Masaki Kamada
- Department of Neurological Intractable Disease Research, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan;
| | - Masaki Ueno
- Department of Pathology and Host Defense, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kita-gun, Kagawa 761-0793, Japan; (Y.C.); (R.M.); (K.M.); (K.W.)
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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: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [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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30
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Geiger D. Plant glucose transporter structure and function. Pflugers Arch 2020; 472:1111-1128. [PMID: 32845347 PMCID: PMC8298354 DOI: 10.1007/s00424-020-02449-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/06/2020] [Accepted: 08/10/2020] [Indexed: 12/01/2022]
Abstract
The carbohydrate D-glucose is the main source of energy in living organisms. In contrast to animals, as well as most fungi, bacteria, and archaea, plants are capable to synthesize a surplus of sugars characterizing them as autothrophic organisms. Thus, plants are de facto the source of all food on earth, either directly or indirectly via feed to livestock. Glucose is stored as polymeric glucan, in animals as glycogen and in plants as starch. Despite serving a general source for metabolic energy and energy storage, glucose is the main building block for cellulose synthesis and represents the metabolic starting point of carboxylate- and amino acid synthesis. Finally yet importantly, glucose functions as signalling molecule conveying the plant metabolic status for adjustment of growth, development, and survival. Therefore, cell-to-cell and long-distance transport of photoassimilates/sugars throughout the plant body require the fine-tuned activity of sugar transporters facilitating the transport across membranes. The functional plant counterparts of the animal sodium/glucose transporters (SGLTs) are represented by the proton-coupled sugar transport proteins (STPs) of the plant monosaccharide transporter(-like) family (MST). In the framework of this special issue on “Glucose Transporters in Health and Disease,” this review gives an overview of the function and structure of plant STPs in comparison to the respective knowledge obtained with the animal Na+-coupled glucose transporters (SGLTs).
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Affiliation(s)
- Dietmar Geiger
- Institute for Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, Biocenter, University of Wuerzburg, 97082, Wuerzburg, Germany.
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31
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Ren Y, Zhao Z, Zhao G, Liu Q, Wang Z, Liu R. Sleeve Gastrectomy Surgery Improves Glucose Metabolism by Downregulating the Intestinal Expression of Sodium-Glucose Cotransporter-3. J INVEST SURG 2020; 35:14-22. [PMID: 32835540 DOI: 10.1080/08941939.2020.1810370] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
AIMS Sleeve gastrectomy (SG) has been proven effective in the treatment of obesity and type 2 diabetes. We hypothesized that SGLT3 may play an important role in the mechanism of glucose control and weight loss after SG. MATERIALS AND METHODS Daily body weight and food intake were measured in SG and sham-operated mice. Glucose tolerance test, SGLT3 agonist (αMG), and SGLT1 inhibitor (phlorizin) perfusion experiments were used to detect changes in intestinal SGLT3 and SGLT1 activity following SG. Expression of SGLT3a and SGLT1 was assessed at 2 weeks, 1 month after surgery by quantitative PCR and fluorescence immunoassay. Hematoxylin and eosin staining was used to detect morphological changes in the villi. SGLT3 and SGLT1 expression was measured after stimulation of human intestinal epithelial cells (HIEC). RESULTS Both the body weight and daily food intake of the SG-treated mice decreased within 30 days after surgery. Oral glucose absorption was significantly reduced at 30 days. The intestinal stimulation proved that SG can improve glucose metabolism, which can be reversed by αMG and enhanced by phlorizin. Villus height and surface area of the intestine in SG mice decreased after surgery. mRNA expression of SGLT3a and SGLT1 decreased at 2 weeks and 1 month after SG, immunofluorescence also confirmed these changes. HIEC stimulation confirmed that αMG could increase the expression of SGLT3 and SGLT1, but the expression of SGLT1 was down regulated when phlorizin was added to the medium. CONCLUSION The results suggest that reducing SGLT3 expression might contribute to lowering blood glucose and controlling body weight after SG.
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Affiliation(s)
- Yixing Ren
- Department of Hepatopancreatobiliary Surgical Oncology, The First Medical Center of the General Hospital of People's Liberation Army, Beijing, China
| | - Zhiming Zhao
- Department of Hepatopancreatobiliary Surgical Oncology, The First Medical Center of the General Hospital of People's Liberation Army, Beijing, China
| | - Guodong Zhao
- Department of Hepatopancreatobiliary Surgical Oncology, The First Medical Center of the General Hospital of People's Liberation Army, Beijing, China
| | - Qu Liu
- Department of Hepatopancreatobiliary Surgical Oncology, The First Medical Center of the General Hospital of People's Liberation Army, Beijing, China
| | - Zizheng Wang
- Department of Hepatopancreatobiliary Surgical Oncology, The First Medical Center of the General Hospital of People's Liberation Army, Beijing, China
| | - Rong Liu
- Department of Hepatopancreatobiliary Surgical Oncology, The First Medical Center of the General Hospital of People's Liberation Army, Beijing, China
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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: 219] [Impact Index Per Article: 54.8] [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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Wang X, Guo K, Huang B, Lin Z, Cai Z. Role of Glucose Transporters in Drug Membrane Transport. Curr Drug Metab 2020; 21:947-958. [PMID: 32778021 DOI: 10.2174/1389200221666200810125924] [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: 03/31/2020] [Revised: 05/12/2020] [Accepted: 06/01/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Glucose is the main energy component of cellular activities. However, as a polar molecule, glucose cannot freely pass through the phospholipid bilayer structure of the cell membrane. Thus, glucose must rely on specific transporters in the membrane. Drugs with a similar chemical structure to glucose may also be transported through this pathway. METHODS This review describes the structure, distribution, action mechanism and influencing factors of glucose transporters and introduces the natural drugs mediated by these transporters and drug design strategies on the basis of this pathway. RESULTS The glucose transporters involved in glucose transport are of two major types, namely, Na+-dependent and Na+-independent transporters. Glucose transporters can help some glycoside drugs cross the biological membrane. The transmembrane potential is influenced by the chemical structure of drugs. Glucose can be used to modify drugs and improve their ability to cross biological barriers. CONCLUSION The membrane transport mechanism of some glycoside drugs may be related to glucose transporters. Glucose modification may improve the oral bioavailability of drugs or achieve targeted drug delivery.
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Affiliation(s)
- Xin Wang
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Kunkun Guo
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Baolin Huang
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Zimin Lin
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Zheng Cai
- Guangdong Provincial Key Laboratory of New Drug Screening, School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
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Sodium-glucose co-transporter (SGLT) inhibitor restores lost axonal varicosities of the myenteric plexus in a mouse model of high-fat diet-induced obesity. Sci Rep 2020; 10:12372. [PMID: 32704004 PMCID: PMC7378553 DOI: 10.1038/s41598-020-69256-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 07/08/2020] [Indexed: 01/19/2023] Open
Abstract
Diabetes impairs enteric nervous system functions; however, ultrastructural changes underlying the pathophysiology of the myenteric plexus and the effects of sodium-glucose co-transporter (SGLT) inhibitors are poorly understood. This study aimed to investigate three-dimensional ultrastructural changes in axonal varicosities in the myenteric plexus and the effect thereon of the SGLT inhibitor phlorizin in mice fed a high-fat diet (HFD). Three-dimensional ultrastructural analysis using serial block-face imaging revealed that non-treated HFD-fed mice had fewer axonal varicosities and synaptic vesicles in the myenteric plexus than did normal diet-fed control mice. Furthermore, mitochondrial volume was increased and lysosome number decreased in the axons of non-treated HFD-fed mice when compared to those of control mice. Phlorizin treatment restored the axonal varicosities and organelles in HFD-fed mice. Although HFD did not affect the immunolocalisation of PGP9.5, it reduced synaptophysin immunostaining in the myenteric plexus, which was restored by phlorizin treatment. These results suggest that impairment of the axonal varicosities and their synaptic vesicles underlies the damage to the enteric neurons caused by HFD feeding. SGLT inhibitor treatment could restore axonal varicosities and organelles, which may lead to improved gastrointestinal functions in HFD-induced obesity as well as diabetes.
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35
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Sano R, Shinozaki Y, Ohta T. Sodium-glucose cotransporters: Functional properties and pharmaceutical potential. J Diabetes Investig 2020; 11:770-782. [PMID: 32196987 PMCID: PMC7378437 DOI: 10.1111/jdi.13255] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 03/06/2020] [Accepted: 03/13/2020] [Indexed: 02/06/2023] Open
Abstract
Glucose is the most abundant monosaccharide, and an essential source of energy for most living cells. Glucose transport across the cell membrane is mediated by two types of transporters: facilitative glucose transporters (gene name: solute carrier 2A) and sodium-glucose cotransporters (SGLTs; gene name: solute carrier 5A). Each transporter has its own substrate specificity, distribution, and regulatory mechanisms. Recently, SGLT1 and SGLT2 have attracted much attention as therapeutic targets for various diseases. This review addresses the basal and functional properties of glucose transporters and SGLTs, and describes the pharmaceutical potential of SGLT1 and SGLT2.
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Affiliation(s)
- Ryuhei Sano
- Biological/Pharmacological Research LaboratoriesCentral Pharmaceutical Research InstituteJapan Tobacco IncTakatsukiJapan
| | - Yuichi Shinozaki
- Biological/Pharmacological Research LaboratoriesCentral Pharmaceutical Research InstituteJapan Tobacco IncTakatsukiJapan
| | - Takeshi Ohta
- Laboratory of Animal Physiology and Functional AnatomyGraduate School of AgricultureKyoto UniversityKyotoJapan
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36
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Heterogeneity of Glucose Transport in Lung Cancer. Biomolecules 2020; 10:biom10060868. [PMID: 32517099 PMCID: PMC7356687 DOI: 10.3390/biom10060868] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 05/28/2020] [Accepted: 05/29/2020] [Indexed: 02/06/2023] Open
Abstract
Increased glucose uptake is a known hallmark of cancer. Cancer cells need glucose for energy production via glycolysis and the tricarboxylic acid cycle, and also to fuel the pentose phosphate pathway, the serine biosynthetic pathway, lipogenesis, and the hexosamine pathway. For this reason, glucose transport inhibition is an emerging new treatment for different malignancies, including lung cancer. However, studies both in animal models and in humans have shown high levels of heterogeneity in the utilization of glucose and other metabolites in cancer, unveiling a complexity that is difficult to target therapeutically. Here, we present an overview of different levels of heterogeneity in glucose uptake and utilization in lung cancer, with diagnostic and therapeutic implications.
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37
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Sada K, Hidaka S, Imaishi N, Shibata K, Katashima R, Noso S, Ikegami H, Kakuma T, Shibata H. Clinical and genetic analysis in a family with familial renal glucosuria: Identification of an N101K mutation in the sodium-glucose cotransporter 2 encoded by a solute carrier family 5 member 2 gene. J Diabetes Investig 2020; 11:573-577. [PMID: 31584752 PMCID: PMC7232273 DOI: 10.1111/jdi.13157] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Revised: 09/25/2019] [Accepted: 10/02/2019] [Indexed: 01/19/2023] Open
Abstract
We report the identification of a mutation in the solute carrier family 5 member 2 (SLC5A2) gene, which encodes sodium-glucose cotransporter 2, in a family with familial renal glucosuria. The proband was a 26-year-old Japanese man referred to the diabetes division with repeated glucosuria without hyperglycemia. His mother, uncle and grandfather also had a history of glucosuria. A heterozygous missense mutation (c.303T>A:p.N101K) in SLC5A2 was identified in the patient and his mother, but not in 200 chromosomes from 100 healthy and unrelated individuals, or in 3,408 Japanese individuals in the Tohoku Medical Megabank. Furthermore, bioinformatics software predicted that this lesion would be pathogenic. We infer that the mutation led to clinically relevant sodium-glucose cotransporter 2 dysfunction. The patient showed no symptoms of hypoglycemia, but continuous glucose monitoring confirmed asymptomatic hypoglycemia.
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Affiliation(s)
- Kentaro Sada
- Department of Diabetes and MetabolismKoseiren Tsurumi HospitalOitaJapan
| | - Shuji Hidaka
- Department of Diabetes and MetabolismKoseiren Tsurumi HospitalOitaJapan
| | - Nao Imaishi
- Department of Diabetes and MetabolismKoseiren Tsurumi HospitalOitaJapan
| | - Kohei Shibata
- Department of Gastrointestinal SurgeryKoseiren Tsurumi HospitalOitaJapan
| | - Rumi Katashima
- Laboratory for Pediatric Genome MedicineDepartment of Clinical ResearchNational Hospital Organization Shikoku Medical Center for Children and AdultsKagawaJapan
| | - Shinsuke Noso
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsakaJapan
| | - Hiroshi Ikegami
- Department of Endocrinology, Metabolism and DiabetesFaculty of MedicineKindai UniversityOsakaJapan
| | - Tetsuya Kakuma
- Department of Health Support CenterOita UniversityOitaJapan
| | - Hirotaka Shibata
- Department of Endocrinology, Metabolism, Rheumatology and NephrologyFaculty of MedicineOita UniversityOitaJapan
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Kshirsagar RP, Kulkarni AA, Chouthe RS, Pathan SK, Une HD, Reddy GB, Diwan PV, Ansari SA, Sangshetti JN. SGLT inhibitors as antidiabetic agents: a comprehensive review. RSC Adv 2020; 10:1733-1756. [PMID: 35494673 PMCID: PMC9048284 DOI: 10.1039/c9ra08706k] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/18/2019] [Indexed: 12/12/2022] Open
Abstract
Diabetes is one of the most common disorders that substantially contributes to an increase in global health burden. As a metabolic disorder, diabetes is associated with various medical conditions and diseases such as obesity, hypertension, cardiovascular diseases, and atherosclerosis. In this review, we cover the scientific studies on sodium/glucose cotransporter (SGLT) inhibitors published during the last decade. Our focus on providing an exhaustive overview of SGLT inhibitors enabled us to present their chemical classification for the first time.
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Affiliation(s)
| | | | - Rashmi S Chouthe
- Srinath Institute of Pharmaceutical Education and Research Bajaj Nagar Waluj Aurangabad 431136 India
| | | | - Hemant D Une
- Y. B. Chavan College of Pharmacy Aurangabad Maharashtra India - 431001
| | - G Bhanuprakash Reddy
- Department of Biochemistry, National Institute of Nutrition (ICMR) Hyderabad Telangana India - 500007
| | - Prakash V Diwan
- Maratha Mandal Research Centre Belagavi Karnataka India - 590019
| | - Siddique Akber Ansari
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University Po Box 2454 Riyadh 11451 Saudi Arabia
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Knauf C, Abot A, Wemelle E, Cani PD. Targeting the Enteric Nervous System to Treat Metabolic Disorders? "Enterosynes" as Therapeutic Gut Factors. Neuroendocrinology 2020; 110:139-146. [PMID: 31280267 DOI: 10.1159/000500602] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 04/28/2019] [Indexed: 11/19/2022]
Abstract
The gut-brain axis is of crucial importance for controlling glucose homeostasis. Alteration of this axis promotes the type 2 diabetes (T2D) phenotype (hyperglycaemia, insulin resistance). Recently, a new concept has emerged to demonstrate the crucial role of the enteric nervous system in the control of glycaemia via the hypothalamus. In diabetic patients and mice, modification of enteric neurons activity in the proximal part of the intestine generates a duodenal hyper-contractility that generates an aberrant message from the gut to the brain. In turn, the hypothalamus sends an aberrant efferent message that provokes a state of insulin resistance, which is characteristic of a T2D state. Targeting the enteric nervous system of the duodenum is now recognized as an innovative strategy for treatment of diabetes. By acting in the intestine, bioactive gut molecules that we called "enterosynes" can modulate the function of a specific type of neurons of the enteric nervous system to decrease the contraction of intestinal smooth muscle cells. Here, we focus on the origins of enterosynes (hormones, neurotransmitters, nutrients, microbiota, and immune factors), which could be considered therapeutic factors, and we describe their modes of action on enteric neurons. This unsuspected action of enterosynes is proposed for the treatment of T2D, but it could be applied for other therapeutic solutions that implicate communication between the gut and brain.
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Affiliation(s)
- Claude Knauf
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1220, Université Paul Sabatier, UPS, Institut de Recherche en Santé Digestive et Nutrition (IRSD), Toulouse, France,
- NeuroMicrobiota, European Associated Laboratory (EAL) INSERM, Toulouse, France,
| | - Anne Abot
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1220, Université Paul Sabatier, UPS, Institut de Recherche en Santé Digestive et Nutrition (IRSD), Toulouse, France
- NeuroMicrobiota, European Associated Laboratory (EAL) INSERM, Toulouse, France
| | - Eve Wemelle
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1220, Université Paul Sabatier, UPS, Institut de Recherche en Santé Digestive et Nutrition (IRSD), Toulouse, France
- NeuroMicrobiota, European Associated Laboratory (EAL) INSERM, Toulouse, France
| | - Patrice D Cani
- NeuroMicrobiota, European Associated Laboratory (EAL) INSERM, Toulouse, France
- UCLouvain, Université Catholique de Louvain, WELBIO - Walloon Excellence in Life Sciences and BIOtechnology, Louvain Drug Research Institute, Metabolism and Nutrition Research Group, Brussels, Belgium
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Lizák B, Szarka A, Kim Y, Choi KS, Németh CE, Marcolongo P, Benedetti A, Bánhegyi G, Margittai É. Glucose Transport and Transporters in the Endomembranes. Int J Mol Sci 2019; 20:ijms20235898. [PMID: 31771288 PMCID: PMC6929180 DOI: 10.3390/ijms20235898] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 11/16/2019] [Accepted: 11/21/2019] [Indexed: 12/18/2022] Open
Abstract
Glucose is a basic nutrient in most of the creatures; its transport through biological membranes is an absolute requirement of life. This role is fulfilled by glucose transporters, mediating the transport of glucose by facilitated diffusion or by secondary active transport. GLUT (glucose transporter) or SLC2A (Solute carrier 2A) families represent the main glucose transporters in mammalian cells, originally described as plasma membrane transporters. Glucose transport through intracellular membranes has not been elucidated yet; however, glucose is formed in the lumen of various organelles. The glucose-6-phosphatase system catalyzing the last common step of gluconeogenesis and glycogenolysis generates glucose within the lumen of the endoplasmic reticulum. Posttranslational processing of the oligosaccharide moiety of glycoproteins also results in intraluminal glucose formation in the endoplasmic reticulum (ER) and Golgi. Autophagic degradation of polysaccharides, glycoproteins, and glycolipids leads to glucose accumulation in lysosomes. Despite the obvious necessity, the mechanism of glucose transport and the molecular nature of mediating proteins in the endomembranes have been hardly elucidated for the last few years. However, recent studies revealed the intracellular localization and functional features of some glucose transporters; the aim of the present paper was to summarize the collected knowledge.
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Affiliation(s)
- Beáta Lizák
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, 1094 Budapest, Hungary; (B.L.); (C.E.N.); (G.B.)
| | - András Szarka
- Laboratory of Biochemistry and Molecular Biology, Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, 1111 Budapest, Hungary;
| | - Yejin Kim
- Institute of Translational Medicine, Semmelweis University, 1094 Budapest, Hungary; (Y.K.); (K.-s.C.)
| | - Kyu-sung Choi
- Institute of Translational Medicine, Semmelweis University, 1094 Budapest, Hungary; (Y.K.); (K.-s.C.)
| | - Csilla E. Németh
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, 1094 Budapest, Hungary; (B.L.); (C.E.N.); (G.B.)
| | - Paola Marcolongo
- Department of Molecular and Developmental Medicine, University of Siena, 53100 Siena, Italy; (P.M.); (A.B.)
| | - Angelo Benedetti
- Department of Molecular and Developmental Medicine, University of Siena, 53100 Siena, Italy; (P.M.); (A.B.)
| | - Gábor Bánhegyi
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, 1094 Budapest, Hungary; (B.L.); (C.E.N.); (G.B.)
| | - Éva Margittai
- Institute of Translational Medicine, Semmelweis University, 1094 Budapest, Hungary; (Y.K.); (K.-s.C.)
- Correspondence: ; Tel.: +36-459-1500 (ext. 60311); Fax: +36-1-2662615
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Liu B, Wang Y, Zhang Y, Yan B. Mechanisms of Protective Effects of SGLT2 Inhibitors in Cardiovascular Disease and Renal Dysfunction. Curr Top Med Chem 2019; 19:1818-1849. [PMID: 31456521 DOI: 10.2174/1568026619666190828161409] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/09/2019] [Accepted: 07/25/2019] [Indexed: 02/07/2023]
Abstract
Type 2 diabetes mellitus is one of the most common forms of the disease worldwide. Hyperglycemia and insulin resistance play key roles in type 2 diabetes mellitus. Renal glucose reabsorption is an essential feature in glycaemic control. Kidneys filter 160 g of glucose daily in healthy subjects under euglycaemic conditions. The expanding epidemic of diabetes leads to a prevalence of diabetes-related cardiovascular disorders, in particular, heart failure and renal dysfunction. Cellular glucose uptake is a fundamental process for homeostasis, growth, and metabolism. In humans, three families of glucose transporters have been identified, including the glucose facilitators GLUTs, the sodium-glucose cotransporter SGLTs, and the recently identified SWEETs. Structures of the major isoforms of all three families were studied. Sodium-glucose cotransporter (SGLT2) provides most of the capacity for renal glucose reabsorption in the early proximal tubule. A number of cardiovascular outcome trials in patients with type 2 diabetes have been studied with SGLT2 inhibitors reducing cardiovascular morbidity and mortality. The current review article summarises these aspects and discusses possible mechanisms with SGLT2 inhibitors in protecting heart failure and renal dysfunction in diabetic patients. Through glucosuria, SGLT2 inhibitors reduce body weight and body fat, and shift substrate utilisation from carbohydrates to lipids and, possibly, ketone bodies. These pleiotropic effects of SGLT2 inhibitors are likely to have contributed to the results of the EMPA-REG OUTCOME trial in which the SGLT2 inhibitor, empagliflozin, slowed down the progression of chronic kidney disease and reduced major adverse cardiovascular events in high-risk individuals with type 2 diabetes. This review discusses the role of SGLT2 in the physiology and pathophysiology of renal glucose reabsorption and outlines the unexpected logic of inhibiting SGLT2 in the diabetic kidney.
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Affiliation(s)
- Ban Liu
- Department of Cardiology, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yuliang Wang
- Department of Immunology, Nanjing Medical University, Nanjing, China
| | - Yangyang Zhang
- Key Laboratory of Arrhythmias of the Ministry of Education of China, Tongji University School of Medicine, Shanghai, China.,Department of Cardiovascular Surgery, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, China
| | - Biao Yan
- Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, China.,Eye Institute, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China
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Regulation of Skeletal Muscle Glucose Transport and Glucose Metabolism by Exercise Training. Nutrients 2019; 11:nu11102432. [PMID: 31614762 PMCID: PMC6835691 DOI: 10.3390/nu11102432] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 09/30/2019] [Accepted: 10/08/2019] [Indexed: 12/22/2022] Open
Abstract
Aerobic exercise training and resistance exercise training are both well-known for their ability to improve human health; especially in individuals with type 2 diabetes. However, there are critical differences between these two main forms of exercise training and the adaptations that they induce in the body that may account for their beneficial effects. This article reviews the literature and highlights key gaps in our current understanding of the effects of aerobic and resistance exercise training on the regulation of systemic glucose homeostasis, skeletal muscle glucose transport and skeletal muscle glucose metabolism.
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43
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Zhang L, Wang M, Castan A, Stevenson J, Chatzissavidou N, Hjalmarsson H, Vilaplana F, Chotteau V. Glycan Residues Balance Analysis - GReBA: A novel model for the N-linked glycosylation of IgG produced by CHO cells. Metab Eng 2019; 57:118-128. [PMID: 31539564 DOI: 10.1016/j.ymben.2019.08.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 07/12/2019] [Accepted: 08/22/2019] [Indexed: 02/02/2023]
Abstract
The structure of N-linked glycosylation is a very important quality attribute for therapeutic monoclonal antibodies. Different carbon sources in cell culture media, such as mannose and galactose, have been reported to have different influences on the glycosylation patterns. Accurate prediction and control of the glycosylation profile are important for the process development of mammalian cell cultures. In this study, a mathematical model, that we named Glycan Residues Balance Analysis (GReBA), was developed based on the concept of Elementary Flux Mode (EFM), and used to predict the glycosylation profile for steady state cell cultures. Experiments were carried out in pseudo-perfusion cultivation of antibody producing Chinese Hamster Ovary (CHO) cells with various concentrations and combinations of glucose, mannose and galactose. Cultivation of CHO cells with mannose or the combinations of mannose and galactose resulted in decreased lactate and ammonium production, and more matured glycosylation patterns compared to the cultures with glucose. Furthermore, the growth rate and IgG productivity were similar in all the conditions. When the cells were cultured with galactose alone, lactate was fed as well to be used as complementary carbon source, leading to cell growth rate and IgG productivity comparable to feeding the other sugars. The data of the glycoprofiles were used for training the model, and then to simulate the glycosylation changes with varying the concentrations of mannose and galactose. In this study we showed that the GReBA model had a good predictive capacity of the N-linked glycosylation. The GReBA can be used as a guidance for development of glycoprotein cultivation processes.
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Affiliation(s)
- Liang Zhang
- Department of Industrial Biotechnology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Sweden; AdBIOPRO, VINNOVA Competence Centre for Advanced Bioproduction by Continuous Processing, KTH, Sweden
| | - MingLiang Wang
- AdBIOPRO, VINNOVA Competence Centre for Advanced Bioproduction by Continuous Processing, KTH, Sweden; Department of Automatic Control, School of Electrical Engineering and Computer Science, KTH-Royal Institute of Technology, Sweden
| | - Andreas Castan
- GE Healthcare Bio-Sciences AB, Björkgatan 30, 75184, Uppsala, Sweden
| | | | | | - Håkan Hjalmarsson
- AdBIOPRO, VINNOVA Competence Centre for Advanced Bioproduction by Continuous Processing, KTH, Sweden; Department of Automatic Control, School of Electrical Engineering and Computer Science, KTH-Royal Institute of Technology, Sweden
| | - Francisco Vilaplana
- Division of Glycoscience, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Sweden
| | - Veronique Chotteau
- Department of Industrial Biotechnology, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH-Royal Institute of Technology, Sweden; AdBIOPRO, VINNOVA Competence Centre for Advanced Bioproduction by Continuous Processing, KTH, Sweden.
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44
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Cannizzaro M, Jarošová J, De Paepe B. Relevance of solute carrier family 5 transporter defects to inherited and acquired human disease. J Appl Genet 2019; 60:305-317. [PMID: 31286439 DOI: 10.1007/s13353-019-00502-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 06/21/2019] [Accepted: 06/30/2019] [Indexed: 01/12/2023]
Abstract
The solute carrier (SLC) group of membrane transport proteins is crucial for cells via their control of import and export of vital molecules across the cellular membrane. Defects in these transporters with narrow substrate specificities cause monogenic disorders, giving us essential clues of their precise roles in cellular functioning. The SLC5 family in particular has been linked to various human diseases, of mild and severe phenotype as well as high and low prevalence. In this review, we describe the effects on health of SLC5 dysfunction and dysregulation by summarizing findings in patients with transporter gene defects. Patients display a plethora of pathologies which include glucose/galactose malabsorption, familiar renal glycosuria, thyroid dyshormonogenesis, and distal hereditary motor neuronopathies. In addition, the therapeutic potential of intervening in transporter activities for treating common diseases such as diabetes and cancer is explored.
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Affiliation(s)
- Miryam Cannizzaro
- Department of Neurology & Neuromuscular Reference Center, Ghent University Hospital, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Jana Jarošová
- Department of Neurology & Neuromuscular Reference Center, Ghent University Hospital, Corneel Heymanslaan 10, 9000, Ghent, Belgium
| | - Boel De Paepe
- Department of Neurology & Neuromuscular Reference Center, Ghent University Hospital, Corneel Heymanslaan 10, 9000, Ghent, Belgium.
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45
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Schmidt L, Wielsch N, Wang D, Boland W, Burse A. Tissue-specific profiling of membrane proteins in the salicin sequestering juveniles of the herbivorous leaf beetle, Chrysomela populi. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2019; 109:81-91. [PMID: 30922827 DOI: 10.1016/j.ibmb.2019.03.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/21/2019] [Accepted: 03/21/2019] [Indexed: 06/09/2023]
Abstract
Sequestration of plant secondary metabolites is a detoxification strategy widespread in herbivorous insects including not only storage, but also usage of these metabolites for the insects' own benefit. Larvae of the poplar leaf beetle Chrysomela populi sequester plant-derived salicin to produce the deterrent salicylaldehyde in specialized exocrine glands. To identify putative transporters involved in the sequestration process we investigated integral membrane proteins of several tissues from juvenile C. populi by using a proteomics approach. Computational analyses led to the identification of 122 transport proteins in the gut, 105 in the Malpighian tubules, 94 in the fat body and 27 in the defensive glands. Among these, primary active transporters as well as electrochemical potential-driven transporters were most abundant in all tissues, including ABC transporters (especially subfamilies B, C and G) and sugar porters as most interesting families facilitating the sequestration of plant glycosides. Whereas ABC transporters are predominantly expressed simultaneously in several tissues, sugar porters are often expressed in only one tissue, suggesting that sugar porters govern more distinct functions than members of the ABC family. The inventory of transporters presented in this study provides the base for further functional characterizations on transport processes of sequestered glycosides in insects.
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Affiliation(s)
- Lydia Schmidt
- Max Planck Institute for Chemical Ecology, Department of Bioorganic Chemistry, Hans-Knöll-Str. 8, D-07745, Jena, Germany
| | - Natalie Wielsch
- Max Planck Institute for Chemical Ecology, Research Group Mass Spectrometry/ Proteomics, Hans-Knöll-Str. 8, D-07745, Jena, Germany
| | - Ding Wang
- Max Planck Institute for Chemical Ecology, Department of Bioorganic Chemistry, Hans-Knöll-Str. 8, D-07745, Jena, Germany
| | - Wilhelm Boland
- Max Planck Institute for Chemical Ecology, Department of Bioorganic Chemistry, Hans-Knöll-Str. 8, D-07745, Jena, Germany
| | - Antje Burse
- Max Planck Institute for Chemical Ecology, Department of Bioorganic Chemistry, Hans-Knöll-Str. 8, D-07745, Jena, Germany.
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Chu C, Lu YP, Yin L, Hocher B. The SGLT2 Inhibitor Empagliflozin Might Be a New Approach for the Prevention of Acute Kidney Injury. Kidney Blood Press Res 2019; 44:149-157. [PMID: 30939483 DOI: 10.1159/000498963] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 01/27/2019] [Indexed: 11/19/2022] Open
Abstract
Three randomized control trials (Canagliflozin Cardiovascular Assessment Study, Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients [EMPA-REG OUTCOME], and Dapagliflozin Effect on Cardiovascular Events-Thrombolysis in Myocardial Infarction 58 [DECLARE-TIMI 58]) showed that the sodium-glucose co-transporter 2 (SGLT2) inhibitors, originally developed as glucose-lowering drugs, are associated with a lower rate of adverse renal outcomes, such as need for renal replacement therapy, doubling of serum creatinine, and loss of glomerular filtration rate (GFR) compared to those in placebo groups. Besides, canagliflozin and empagliflozin also showed a lower risk of progression to macroalbuminuria. The EMPA-REG OUTCOME trial and DECLARE-TIMI 58 trial also indicated that these SGLT2 inhibitors might have beneficial effects on the prevention of acute kidney injury. The United States Food and Drug Administration (FDA) warned of the risk of acute kidney injury for canagliflozin and dapagliflozin. We compared canagliflozin, empagliflozin, and dapagliflozin with respect to chemical structure and pharmacological properties, to explain the observed differences in preventing acute kidney injury, and put forward the hypotheses of the potential mechanisms of different effects of SGLT2 inhibitors on acute kidney injury. Given the raising clinical use of SGLT2 inhibitors, our review should stimulate further basic science and clinical studies in order to definitively understand the role of SGLT2 inhibitors in acute kidney injury. A weakness of the clinical data obtained so far is the fact that the statements concerning acute kidney injury are just based on safety data - mainly creatine measurements. However, given the mode of action of SGLT2 blockers, initiation of a therapy with a SGLT2 blocker will cause an increase of creatine because of its effects on the tubuloglomerular feedback mechanisms/glomerular hemodynamics like RAAS blocking agents do. To really understand the potential effects of SGLT2 inhibitors, we need preclinical and clinical SGLT2 inhibitor studies focusing on all aspects of acute kidney injury - not just changes in GFR biomarkers.
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Affiliation(s)
- Chang Chu
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany.,Department of Nephrology, The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Yong-Ping Lu
- Department of Nephrology, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Lianghong Yin
- Department of Nephrology, The First Affiliated Hospital of Jinan University, Guangzhou, China,
| | - Berthold Hocher
- Fifth Department of Medicine (Nephrology/Endocrinology/Rheumatology), University Medical Centre Mannheim, University of Heidelberg, Mannheim, Germany.,Department of Nephrology, The First Affiliated Hospital of Jinan University, Guangzhou, China
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47
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Paes-Leme B, Dos-Santos RC, Mecawi AS, Ferguson AV. Interaction between angiotensin II and glucose sensing at the subfornical organ. J Neuroendocrinol 2018; 30:e12654. [PMID: 30365188 DOI: 10.1111/jne.12654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 09/14/2018] [Accepted: 10/22/2018] [Indexed: 02/06/2023]
Abstract
The subfornical organ (SFO) lacks the normal blood-brain barrier and senses the concentrations of many different circulating signals, including glucose and angiotensin II (ANG II). ANG II has recently been implicated in the control of food intake and body weight gain. The present study assessed whether single SFO neurones sense changes in glucose and ANG II, and also whether changes in glucose concentration alter the responsiveness of these neurones to ANG II. SFO neurones dissociated from male Sprague-Dawley rats (100-175 g) were used. We first examined whether glucose concentration modulates AT1 receptor expression. Similar AT1a mRNA expression levels were found at glucose concentrations of 1, 5 and 10 mmol L-1 in dissociated SFO neurones. Glucose responsiveness of SFO neurones was assessed using perforated current-clamp recordings and switching between 5 and 10 mmol L-1 glucose artificial cerebrospinal fluid to classify single neurones as nonresponsive (nGS), glucose-excited (GE) or glucose-inhibited (GI). In total, 26.7% of the SFO neurones were GI (n = 24 of 90), 21.1% were GE (n = 19 of 90) and 52.2% were nGS (n = 47 of 90). Once classified, the effects of 10 nmol L-1 ANG II on the excitability of these neurones were tested, with 52% of GE (n = 10 of 19), 71% of GI (n = 17 of 24) and 43% of nGS (n = 20 of 47) neurones being ANG II sensitive. Finally, we tested whether acute changes in glucose concentration modified the response to ANG II and showed that some neurones (4/17) only respond to ANG II at 10 mmol L-1 glucose. Our data demonstrate that the same SFO neurone can sense glucose and ANG II and that acute changes in glucose concentration may change ANG II responsiveness.
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Affiliation(s)
- Bruno Paes-Leme
- Department of Physiological Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil
| | - Raoni C Dos-Santos
- Department of Physiological Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil
| | - André S Mecawi
- Department of Physiological Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil
- Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, Brazil
| | - Alastair V Ferguson
- Centre for Neurosciences Studies, Queen's University, Kingston, Ontario, Canada
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48
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Inhibitory effect of luminal saccharides on glucose absorption from an adjacent jejunal site in rats: a newly described intestinal neural reflex. Pflugers Arch 2018; 471:595-603. [PMID: 30402765 DOI: 10.1007/s00424-018-2230-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2018] [Revised: 10/23/2018] [Accepted: 10/25/2018] [Indexed: 12/20/2022]
Abstract
Nutrients in the lumen of the small intestine are sensed by special cells in the epithelial lining. The ensuing neurohumoral reflexes affect gastrointestinal absorption/secretion, motility, and vascular perfusion. To study in vivo the effect of a monosaccharide (glucose) or polysaccharide (starch) present in the jejunum on glucose absorption from an adjacent part of the intestine and investigate the possible underlying mechanisms. Using the single pass intraluminal perfusion technique, a segment of jejunum (perfusion segment) was continuously perfused with 20 mM glucose to determine glucose absorption. One hour later, a bolus of a saccharide was instilled in an isolated adjacent jejunal segment and the change in glucose absorption was monitored for a further 2 h. The contribution of neural mechanisms in this process was investigated. Instillation of glucose (20 mM or 40 mM) in either distal or proximal jejunal pouch elicited immediate and sustained inhibition of glucose absorption (a decrease by 25%; P < 0.01) from the perfused jejunal segment. Comparable inhibition was obtained with instillation of other monosaccharides or starch in the jejunal pouch. This inhibition was abolished by adding tetrodotoxin to the pouch or to the perfused jejunal segment and also by pretreatment with sympathetic blockers (guanethidine or hexamethonium) and by chemical ablation of capsaicin-sensitive primary afferent fibers. Glucose absorption within the jejunum is auto-regulated through backward and forward mechanisms. This regulation is mediated by neural reflexes involving capsaicin-sensitive afferent and sympathetic efferent fibers. These reflexes might serve to protect against hyperglycemia.
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49
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Schäfer N, Rikkala PR, Veyhl-Wichmann M, Keller T, Jurowich CF, Geiger D, Koepsell H. A Modified Tripeptide Motif of RS1 ( RSC1A1) Down-Regulates Exocytotic Pathways of Human Na +-d-glucose Cotransporters SGLT1, SGLT2, and Glucose Sensor SGLT3 in the Presence of Glucose. Mol Pharmacol 2018; 95:82-96. [PMID: 30355744 DOI: 10.1124/mol.118.113514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 10/19/2018] [Indexed: 12/11/2022] Open
Abstract
A domain of protein RS1 (RSC1A1) called RS1-Reg down-regulates the plasma membrane abundance of Na+-d-glucose cotransporter SGLT1 by blocking the exocytotic pathway at the trans-Golgi. This effect is blunted by intracellular glucose but prevails when serine in a QSP (Gln-Ser-Pro) motif is replaced by glutamate [RS1-Reg(S20E)]. RS1-Reg binds to ornithine decarboxylase (ODC) and inhibits ODC in a glucose-dependent manner. Because the ODC inhibitor difluoromethylornithine (DFMO) acts like RS1-Reg(S20E), and DFMO and RS1-Reg(S20E) are not cumulative, we raised the hypothesis that RS1-Reg(S20E) down-regulates the exocytotic pathway of SGLT1 at the trans-Golgi by inhibiting ODC. We investigated whether QEP down-regulates human SGLT1 (hSGLT1) like hRS1-Reg(S20E) and whether human Na+-d-glucose cotransporter hSGLT2 and the human glucose sensor hSGLT3 are also addressed. We expressed hSGLT1, hSGLT1 linked to yellow fluorescent protein (hSGLT1-YFP), hSGLT2-YFP and hSGLT3-YFP in oocytes of Xenopus laevis, injected hRS1-Reg(S20E), QEP, DFMO, and/or α-methyl-d-glucopyranoside (AMG), and measured AMG uptake, glucose-induced currents, and plasma membrane-associated fluorescence after 1 hour. We also performed in vitro AMG uptake measurements into small intestinal mucosa of mice and human. The data indicate that QEP down-regulates the exocytotic pathway of SGLT1 similar to hRS1-Reg(S20E). Our results suggests that both peptides also down-regulate hSGLT2 and hSGLT3 via the same pathway. Thirty minutes after application of 5 mM QEP in the presence of 5 mM d-glucose, hSGLT1-mediated AMG uptake into small intestinal mucosa was decreased by 40% to 50%. Thus oral application of QEP in a formulation that optimizes uptake into enterocytes but prevents entry into the blood is proposed as novel antidiabetic therapy.
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Affiliation(s)
- Nadine Schäfer
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute (N.S., T.K., D.G., H.K.) and Institute of Anatomy and Cell Biology (P.R.R., M.V.-W., H.K.), University of Würzburg, Würzburg, Germany; and Department of General, Visceral, Vascular, and Paedriatic Surgery, University Hospital of Würzburg, Würzburg, Germany (C.F.J.)
| | - Prashanth Reddy Rikkala
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute (N.S., T.K., D.G., H.K.) and Institute of Anatomy and Cell Biology (P.R.R., M.V.-W., H.K.), University of Würzburg, Würzburg, Germany; and Department of General, Visceral, Vascular, and Paedriatic Surgery, University Hospital of Würzburg, Würzburg, Germany (C.F.J.)
| | - Maike Veyhl-Wichmann
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute (N.S., T.K., D.G., H.K.) and Institute of Anatomy and Cell Biology (P.R.R., M.V.-W., H.K.), University of Würzburg, Würzburg, Germany; and Department of General, Visceral, Vascular, and Paedriatic Surgery, University Hospital of Würzburg, Würzburg, Germany (C.F.J.)
| | - Thorsten Keller
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute (N.S., T.K., D.G., H.K.) and Institute of Anatomy and Cell Biology (P.R.R., M.V.-W., H.K.), University of Würzburg, Würzburg, Germany; and Department of General, Visceral, Vascular, and Paedriatic Surgery, University Hospital of Würzburg, Würzburg, Germany (C.F.J.)
| | - Christian Ferdinand Jurowich
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute (N.S., T.K., D.G., H.K.) and Institute of Anatomy and Cell Biology (P.R.R., M.V.-W., H.K.), University of Würzburg, Würzburg, Germany; and Department of General, Visceral, Vascular, and Paedriatic Surgery, University Hospital of Würzburg, Würzburg, Germany (C.F.J.)
| | - Dietmar Geiger
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute (N.S., T.K., D.G., H.K.) and Institute of Anatomy and Cell Biology (P.R.R., M.V.-W., H.K.), University of Würzburg, Würzburg, Germany; and Department of General, Visceral, Vascular, and Paedriatic Surgery, University Hospital of Würzburg, Würzburg, Germany (C.F.J.)
| | - Hermann Koepsell
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute (N.S., T.K., D.G., H.K.) and Institute of Anatomy and Cell Biology (P.R.R., M.V.-W., H.K.), University of Würzburg, Würzburg, Germany; and Department of General, Visceral, Vascular, and Paedriatic Surgery, University Hospital of Würzburg, Würzburg, Germany (C.F.J.)
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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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