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Weber CM, Moiz B, Clyne AM. Brain microvascular endothelial cell metabolism and its ties to barrier function. VITAMINS AND HORMONES 2024; 126:25-75. [PMID: 39029976 DOI: 10.1016/bs.vh.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2024]
Abstract
Brain microvascular endothelial cells, which lie at the interface between blood and brain, are critical to brain energetics. These cells must precisely balance metabolizing nutrients for their own demands with transporting nutrients into the brain to sustain parenchymal cells. It is essential to understand this integrated metabolism and transport so that we can develop better diagnostics and therapeutics for neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis, and traumatic brain injury. In this chapter, we first describe brain microvascular endothelial cell metabolism and how these cells regulate both blood flow and nutrient transport. We then explain the impact of brain microvascular endothelial cell metabolism on the integrity of the blood-brain barrier, as well as how metabolites produced by the endothelial cells impact other brain cells. We detail some ways that cell metabolism is typically measured experimentally and modeled computationally. Finally, we describe changes in brain microvascular endothelial cell metabolism in aging and neurodegenerative diseases. At the end of the chapter, we highlight areas for future research in brain microvascular endothelial cell metabolism. The goal of this chapter is to underscore the importance of nutrient metabolism and transport at the brain endothelium for cerebral health and neurovascular disease treatment.
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Affiliation(s)
- Callie M Weber
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Bilal Moiz
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States
| | - Alisa Morss Clyne
- Fischell Department of Bioengineering, University of Maryland, College Park, MD, United States.
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2
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Klip A, De Bock K, Bilan PJ, Richter EA. Transcellular Barriers to Glucose Delivery in the Body. Annu Rev Physiol 2024; 86:149-173. [PMID: 38345907 DOI: 10.1146/annurev-physiol-042022-031657] [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] [Indexed: 02/15/2024]
Abstract
Glucose is the universal fuel of most mammalian cells, and it is largely replenished through dietary intake. Glucose availability to tissues is paramount for the maintenance of homeostatic energetics and, hence, supply should match demand by the consuming organs. In its journey through the body, glucose encounters cellular barriers for transit at the levels of the absorbing intestinal epithelial wall, the renal epithelium mediating glucose reabsorption, and the tight capillary endothelia (especially in the brain). Glucose transiting through these cellular barriers must escape degradation to ensure optimal glucose delivery to the bloodstream or tissues. The liver, which stores glycogen and generates glucose de novo, must similarly be able to release it intact to the circulation. We present the most up-to-date knowledge on glucose handling by the gut, liver, brain endothelium, and kidney, and discuss underlying molecular mechanisms and open questions. Diseases associated with defects in glucose delivery and homeostasis are also briefly addressed. We propose that the universal problem of sparing glucose from catabolism in favor of translocation across the barriers posed by epithelia and endothelia is resolved through common mechanisms involving glucose transfer to the endoplasmic reticulum, from where glucose exits the cells via unconventional cellular mechanisms.
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Affiliation(s)
- Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada;
| | - Katrien De Bock
- Laboratory of Exercise and Health, Department of Health Sciences and Technology, Swiss Federal Institute of Technology (ETH), Zürich, Switzerland
| | - Philip J Bilan
- Cell Biology Program, The Hospital for Sick Children, Toronto, Ontario, Canada;
| | - Erik A Richter
- The August Krogh Section for Molecular Physiology, Department of Nutrition, Exercise and Sports, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
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3
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Campeau MA, Leask RL. Empagliflozin reduces endoplasmic reticulum stress associated TXNIP/NLRP3 activation in tunicamycin-stimulated aortic endothelial cells. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:267-279. [PMID: 37421429 DOI: 10.1007/s00210-023-02607-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 06/26/2023] [Indexed: 07/10/2023]
Abstract
Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have proven to be of therapeutic significance for cardiovascular diseases beyond the treatment of type 2 diabetes. Recent studies have demonstrated the beneficial effects of SGLT2i on endothelial cell (EC) dysfunction, but the underlying cellular mechanisms remain to be clarified. In this study, we sought to understand the effect of empagliflozin (EMPA; Jardiance®) on cell homeostasis and endoplasmic reticulum (ER) stress signaling. ER stress was induced by tunicamycin (Tm) in human abdominal aortic ECs treated with EMPA over 24 h. Tm-induced ER stress caused increases in the protein expression of thioredoxin interacting protein (TXNIP), NLR-family pyrin domain-containing protein 3 (NLRP3), C/EBP homologous protein (CHOP), and in the ratio of phospho-eIF2α/eIF2α. EMPA (50-100 µM) resulted in a dampened downstream activation of ER stress as seen by the reduced expression of CHOP and TXNIP/NLRP3 in a dose-dependent manner. Nuclear factor erythroid 2-related factor 2 (nrf2) translocation was also attenuated in EMPA-treated ECs. These results suggest that EMPA improves redox signaling under ER stress which in turn attenuates the activation of TXNIP/NLRP3.
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Affiliation(s)
| | - Richard L Leask
- Department of Chemical Engineering, McGill University, Montreal, QC, Canada.
- McGill University Health Centre, Montreal, QC, Canada.
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4
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Scrimieri R, Locatelli L, Cazzaniga A, Cazzola R, Malucelli E, Sorrentino A, Iotti S, Maier JA. Ultrastructural features mirror metabolic derangement in human endothelial cells exposed to high glucose. Sci Rep 2023; 13:15133. [PMID: 37704683 PMCID: PMC10499809 DOI: 10.1038/s41598-023-42333-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 09/08/2023] [Indexed: 09/15/2023] Open
Abstract
High glucose-induced endothelial dysfunction is the early event that initiates diabetes-induced vascular disease. Here we employed Cryo Soft X-ray Tomography to obtain three-dimensional maps of high D-glucose-treated endothelial cells and their controls at nanometric spatial resolution. We then correlated ultrastructural differences with metabolic rewiring. While the total mitochondrial mass does not change, high D-glucose promotes mitochondrial fragmentation, as confirmed by the modulation of fission-fusion markers, and dysfunction, as demonstrated by the drop of membrane potential, the decreased oxygen consumption and the increased production of reactive oxygen species. The 3D ultrastructural analysis also indicates the accumulation of lipid droplets in cells cultured in high D-glucose. Indeed, because of the decrease of fatty acid β-oxidation induced by high D-glucose concentration, triglycerides are esterified into fatty acids and then stored into lipid droplets. We propose that the increase of lipid droplets represents an adaptive mechanism to cope with the overload of glucose and associated oxidative stress and metabolic dysregulation.
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Affiliation(s)
- Roberta Scrimieri
- Department of Biomedical and Clinical Sciences, Università degli Studi di Milano, 20157, Milan, Italy.
| | - Laura Locatelli
- Department of Biomedical and Clinical Sciences, Università degli Studi di Milano, 20157, Milan, Italy
| | - Alessandra Cazzaniga
- Department of Biomedical and Clinical Sciences, Università degli Studi di Milano, 20157, Milan, Italy
| | - Roberta Cazzola
- Department of Biomedical and Clinical Sciences, Università degli Studi di Milano, 20157, Milan, Italy
| | - Emil Malucelli
- Department of Pharmacy and Biotechnology, Università di Bologna, 40127, Bologna, Italy
| | - Andrea Sorrentino
- Mistral Beamline, ALBA Synchrotron Light Source, Cerdanyola del Valles, 08290, Barcelona, Spain
| | - Stefano Iotti
- Department of Pharmacy and Biotechnology, Università di Bologna, 40127, Bologna, Italy
- National Institute of Biostructures and Biosystems, Viale Delle Medaglie d'Oro 305, 00136, Rome, Italy
| | - Jeanette A Maier
- Department of Biomedical and Clinical Sciences, Università degli Studi di Milano, 20157, Milan, Italy.
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Tian D, Meng J, Li L, Xue H, Geng Q, Miao Y, Xu M, Wang R, Zhang X, Wu Y. Hydrogen sulfide ameliorates senescence in vascular endothelial cells through ameliorating inflammation and activating PPARδ/SGLT2/STAT3 signaling pathway. Acta Biochim Biophys Sin (Shanghai) 2023; 55:1358-1369. [PMID: 37587757 PMCID: PMC10520484 DOI: 10.3724/abbs.2023156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 02/13/2023] [Indexed: 08/18/2023] Open
Abstract
Mounting evidence demonstrates that hydrogen sulfide (H 2S) promotes anti-inflammatory molecules and inhibits pro-inflammatory cytokines in endothelial cells (ECs). This study aims to investigate the favorable action of H 2S on endothelial function in senescence by inhibiting the production of inflammatory molecules. Senescent ECs exhibit a reduction in H 2S, endothelial nitric oxide synthase (eNOS) and peroxisome proliferator-activated receptor δ (PPARδ), coupled with increased inflammatory molecules, sodium glucose transporter type 2 (SGLT2) and phosphorylation of STAT3, which could be reversed by the administration of a slow but sustained release agent of H 2S, GYY4137. Decreased production of eNOS and upregulated p-STAT3 and SGLT2 levels in senescent ECs are reversed by replenishment of the SGLT2 inhibitor EMPA and the PPARδ agonist GW501516. The PPARδ antagonist GSK0660 attenuates eNOS expression and increases the production of p-STAT3 and SGLT2. However, supplementation with GYY4137 has no beneficial effect on GSK0660-treated ECs. GYY4137, GW501516 and EMPA preserve endothelial-dependent relaxation (EDR) in D-gal-treated aortae, while GSK0660 destroys aortic relaxation even with GYY4137 supplementation. In summary, senescent ECs manifest aggravated the expressions of the inflammatory molecules SGLT2 and p-STAT3 and decreased the productions of PPARδ, eNOS and CSE. H 2S ameliorates endothelial dysfunction through the anti-inflammatory effect of the PPARδ/SGLT2/p-STAT3 signaling pathway in senescent ECs and may be a potential therapeutic target for anti-ageing treatment.
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Affiliation(s)
- Danyang Tian
- Department of PhysiologyHebei Medical UniversityShijiazhuang050017China
- Department of PharmacologyTianjin Key Laboratory of Inflammatory BiologySchool of Basic Medical SciencesTianjin Medical UniversityTianjin300070China
| | - Jinqi Meng
- Department of SportsHebei Medical UniversityShijiazhuang050017China
| | - Lin Li
- College of PharmacyHebei Medical UniversityShijiazhuang050017China
| | - Hongmei Xue
- Department of PhysiologyHebei Medical UniversityShijiazhuang050017China
| | - Qi Geng
- Hebei Key Lab of Laboratory Animal ScienceHebei Medical UniversityShijiazhuang050017China
| | - Yuxin Miao
- Department of PhysiologyHebei Medical UniversityShijiazhuang050017China
| | - Meng Xu
- Department of PhysiologyHebei Medical UniversityShijiazhuang050017China
| | - Ru Wang
- Department of PhysiologyHebei Medical UniversityShijiazhuang050017China
| | - Xiangjian Zhang
- Hebei Collaborative Innovation Center for Cardio-Cerebrovascular DiseaseShijiazhuang050017China
| | - Yuming Wu
- Department of PhysiologyHebei Medical UniversityShijiazhuang050017China
- Hebei Collaborative Innovation Center for Cardio-Cerebrovascular DiseaseShijiazhuang050017China
- The Key Laboratory of Neural and Vascular BiologyMinistry of EducationShijiazhuang050017China
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The Sodium-Glucose Co-Transporter 2 (SGLT2) Inhibitor Empagliflozin Reverses Hyperglycemia-Induced Monocyte and Endothelial Dysfunction Primarily through Glucose Transport-Independent but Redox-Dependent Mechanisms. J Clin Med 2023; 12:jcm12041356. [PMID: 36835891 PMCID: PMC9962711 DOI: 10.3390/jcm12041356] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 02/02/2023] [Indexed: 02/10/2023] Open
Abstract
PURPOSE Hyperglycaemia-induced oxidative stress and inflammation contribute to vascular cell dysfunction and subsequent cardiovascular events in T2DM. Selective sodium-glucose co-transporter-2 (SGLT-2) inhibitor empagliflozin significantly improves cardiovascular mortality in T2DM patients (EMPA-REG trial). Since SGLT-2 is known to be expressed on cells other than the kidney cells, we investigated the potential ability of empagliflozin to regulate glucose transport and alleviate hyperglycaemia-induced dysfunction of these cells. METHODS Primary human monocytes were isolated from the peripheral blood of T2DM patients and healthy individuals. Primary human umbilical vein endothelial cells (HUVECs) and primary human coronary artery endothelial cells (HCAECs), and fetoplacental endothelial cells (HPECs) were used as the EC model cells. Cells were exposed to hyperglycaemic conditions in vitro in 40 ng/mL or 100 ng/mL empagliflozin. The expression levels of the relevant molecules were analysed by RT-qPCR and confirmed by FACS. Glucose uptake assays were carried out with a fluorescent derivative of glucose, 2-NBDG. Reactive oxygen species (ROS) accumulation was measured using the H2DFFDA method. Monocyte and endothelial cell chemotaxis were measured using modified Boyden chamber assays. RESULTS Both primary human monocytes and endothelial cells express SGLT-2. Hyperglycaemic conditions did not significantly alter the SGLT-2 levels in monocytes and ECs in vitro or in T2DM conditions. Glucose uptake assays carried out in the presence of GLUT inhibitors revealed that SGLT-2 inhibition very mildly, but not significantly, suppressed glucose uptake by monocytes and endothelial cells. However, we detected the significant suppression of hyperglycaemia-induced ROS accumulation in monocytes and ECs when empagliflozin was used to inhibit SGLT-2 function. Hyperglycaemic monocytes and endothelial cells readily exhibited impaired chemotaxis behaviour. The co-treatment with empagliflozin reversed the PlGF-1 resistance phenotype of hyperglycaemic monocytes. Similarly, the blunted VEGF-A responses of hyperglycaemic ECs were also restored by empagliflozin, which could be attributed to the restoration of the VEGFR-2 receptor levels on the EC surface. The induction of oxidative stress completely recapitulated most of the aberrant phenotypes exhibited by hyperglycaemic monocytes and endothelial cells, and a general antioxidant N-acetyl-L-cysteine (NAC) was able to mimic the effects of empagliflozin. CONCLUSIONS This study provides data indicating the beneficial role of empagliflozin in reversing hyperglycaemia-induced vascular cell dysfunction. Even though both monocytes and endothelial cells express functional SGLT-2, SGLT-2 is not the primary glucose transporter in these cells. Therefore, it seems likely that empagliflozin does not directly prevent hyperglycaemia-mediated enhanced glucotoxicity in these cells by inhibiting glucose uptake. We identified the reduction of oxidative stress by empagliflozin as a primary reason for the improved function of monocytes and endothelial cells in hyperglycaemic conditions. In conclusion, empagliflozin reverses vascular cell dysfunction independent of glucose transport but could partially contribute to its beneficial cardiovascular effects.
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7
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Wu WZ, Bai YP. Endothelial GLUTs and vascular biology. Biomed Pharmacother 2023; 158:114151. [PMID: 36565587 DOI: 10.1016/j.biopha.2022.114151] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/15/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022] Open
Abstract
Endothelial metabolism is a promising target for vascular functional regulation and disease therapy. Glucose is the primary fuel for endothelial metabolism, supporting ATP generation and endothelial cell survival. Multiple studies have discussed the role of endothelial glucose catabolism, such as glycolysis and oxidative phosphorylation, in vascular functional remodeling. However, the role of the first gatekeepers of endothelial glucose utilization, glucose transporters, in the vasculature has long been neglected. Here, this review summarizes glucose transporter studies in vascular research. We mainly focus on GLUT1 and GLUT3 because they are the most critical glucose transporters responsible for most endothelial glucose uptake. Some interesting topics are also discussed, intending to provide directions for endothelial glucose transporter research in the future.
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Affiliation(s)
- Wan-Zhou Wu
- Department of Geriatric Medicine, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China; Center for Vascular Disease and Translational Medicine, Department of Cardiology, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Yong-Ping Bai
- Department of Geriatric Medicine, Xiangya Hospital, Central South University, Changsha, China; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.
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8
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McMillin SL, Evans PL, Taylor WM, Weyrauch LA, Sermersheim TJ, Welc SS, Heitmeier MR, Hresko RC, Hruz PW, Koumanov F, Holman GD, Abel ED, Witczak CA. Muscle-Specific Ablation of Glucose Transporter 1 (GLUT1) Does Not Impair Basal or Overload-Stimulated Skeletal Muscle Glucose Uptake. Biomolecules 2022; 12:1734. [PMID: 36551162 PMCID: PMC9776291 DOI: 10.3390/biom12121734] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/18/2022] [Accepted: 11/21/2022] [Indexed: 11/24/2022] Open
Abstract
Glucose transporter 1 (GLUT1) is believed to solely mediate basal (insulin-independent) glucose uptake in skeletal muscle; yet recent work has demonstrated that mechanical overload, a model of resistance exercise training, increases muscle GLUT1 levels. The primary objective of this study was to determine if GLUT1 is necessary for basal or overload-stimulated muscle glucose uptake. Muscle-specific GLUT1 knockout (mGLUT1KO) mice were generated and examined for changes in body weight, body composition, metabolism, systemic glucose regulation, muscle glucose transporters, and muscle [3H]-2-deoxyglucose uptake ± the GLUT1 inhibitor BAY-876. [3H]-hexose uptake ± BAY-876 was also examined in HEK293 cells-expressing GLUT1-6 or GLUT10. mGLUT1KO mice exhibited no impairments in body weight, lean mass, whole body metabolism, glucose tolerance, basal or overload-stimulated muscle glucose uptake. There was no compensation by the insulin-responsive GLUT4. In mGLUT1KO mouse muscles, overload stimulated higher expression of mechanosensitive GLUT6, but not GLUT3 or GLUT10. In control and mGLUT1KO mouse muscles, 0.05 µM BAY-876 impaired overload-stimulated, but not basal glucose uptake. In the GLUT-HEK293 cells, BAY-876 inhibited glucose uptake via GLUT1, GLUT3, GLUT4, GLUT6, and GLUT10. Collectively, these findings demonstrate that GLUT1 does not mediate basal muscle glucose uptake and suggest that a novel glucose transport mechanism mediates overload-stimulated glucose uptake.
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Affiliation(s)
- Shawna L. McMillin
- Departments of Kinesiology, Biochemistry & Molecular Biology, and Physiology, Brody School of Medicine, East Carolina Diabetes & Obesity Institute, East Carolina University, Greenville, NC 27858, USA
| | - Parker L. Evans
- Departments of Kinesiology, Biochemistry & Molecular Biology, and Physiology, Brody School of Medicine, East Carolina Diabetes & Obesity Institute, East Carolina University, Greenville, NC 27858, USA
| | - William M. Taylor
- Departments of Kinesiology, Biochemistry & Molecular Biology, and Physiology, Brody School of Medicine, East Carolina Diabetes & Obesity Institute, East Carolina University, Greenville, NC 27858, USA
| | - Luke A. Weyrauch
- Departments of Kinesiology, Biochemistry & Molecular Biology, and Physiology, Brody School of Medicine, East Carolina Diabetes & Obesity Institute, East Carolina University, Greenville, NC 27858, USA
| | - Tyler J. Sermersheim
- Department of Anatomy, Cell Biology & Physiology, and Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Steven S. Welc
- Department of Anatomy, Cell Biology & Physiology, and Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Monique R. Heitmeier
- Departments of Pediatrics, and Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - Richard C. Hresko
- Departments of Pediatrics, and Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63130, USA
| | - Paul W. Hruz
- Departments of Pediatrics, and Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63130, USA
| | | | - Geoffrey D. Holman
- Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, UK
| | - E. Dale Abel
- Fraternal Order of Eagles Diabetes Research Center, Division of Endocrinology & Metabolism, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Carol A. Witczak
- Departments of Kinesiology, Biochemistry & Molecular Biology, and Physiology, Brody School of Medicine, East Carolina Diabetes & Obesity Institute, East Carolina University, Greenville, NC 27858, USA
- Department of Anatomy, Cell Biology & Physiology, and Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Indiana Center for Diabetes & Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Yazdani S, Bilan PJ, Jaldin-Fincati JR, Pang J, Ceban F, Saran E, Brumell JH, Freeman SA, Klip A. Dynamic glucose uptake, storage, and release by human microvascular endothelial cells. Mol Biol Cell 2022; 33:ar106. [PMID: 35921166 DOI: 10.1091/mbc.e22-04-0146] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Endothelia determine blood-to-tissue solute delivery, yet glucose transit is poorly understood. To illuminate mechanisms, we tracked [3H]-2-deoxyglucose (2-DG) in human adipose-tissue microvascular endothelial cells. 2-DG uptake was largely facilitated by the glucose transporters GLUT1 and GLUT3. Once in the cytosol, >80% of 2-DG became phosphorylated and ∼20% incorporated into glycogen, suggesting that transported glucose is readily accessible to cytosolic enzymes. Interestingly, a fraction of intracellular 2-DG was released over time (15-20% over 30 min) with slower kinetics than for uptake, involving GLUT3. In contrast to intracellular 2-DG, the released 2-DG was largely unphosphorylated. Glucose release involved endoplasmic reticulum-resident translocases/phosphatases and was stimulated by adrenaline, consistent with participation of glycogenolysis and glucose dephosphorylation. Surprisingly, the fluorescent glucose derivative 2-NBD-glucose (2-NBDG) entered cells largely via fluid phase endocytosis and exited by recycling. 2-NBDG uptake was insensitive to GLUT1/GLUT3 inhibition, suggesting poor influx across membranes. 2-NBDG recycling, but not 2-DG efflux, was sensitive to N-ethyl maleimide. In sum, by utilizing radioactive and fluorescent glucose derivatives, we identified two parallel routes of entry: uptake into the cytosol through dedicated glucose transporters and endocytosis. This reveals the complex glucose handling by endothelial cells that may contribute to glucose delivery to tissues.
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Affiliation(s)
- Samaneh Yazdani
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 0A4
| | - Philip J Bilan
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 0A4
| | | | - Janice Pang
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 0A4
| | - Felicia Ceban
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 0A4
| | - Ekambir Saran
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 0A4
| | - John H Brumell
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 0A4.,Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada, M5S 1A1.,Institute of Medical Science, University of Toronto, Toronto, ON, Canada, M5S 1A1.,SickKids IBD Centre, Hospital for Sick Children, Toronto, ON, Canada, M5G 0A4
| | - Spencer A Freeman
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 0A4.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada, M5S 1A1
| | - Amira Klip
- Cell Biology Program, The Hospital for Sick Children, Toronto, ON, Canada, M5G 0A4.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada, M5S 1A1.,Department of Paediatrics, University of Toronto, Toronto, ON, Canada, M5S 1A1.,Department of Physiology, University of Toronto, Toronto, ON, Canada, M5S 1A1
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10
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Zhang Z, Liu H, Hu X, He Y, Li L, Yang X, Wang C, Hu M, Tao S. Heat Shock Protein 70 Mediates the Protective Effect of Naringenin on High-Glucose-Induced Alterations of Endothelial Function. Int J Endocrinol 2022; 2022:7275765. [PMID: 35958293 PMCID: PMC9359828 DOI: 10.1155/2022/7275765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/02/2022] [Indexed: 11/17/2022] Open
Abstract
Endothelial dysfunction plays a pivotal role in the development and progression of diabetic vascular complications. Naringenin (Nar) is a flavanone bioactive isolated from citrus fruits known to have in vitro and in vivo antidiabetic properties. However, whether Nar affects endothelial function remains unclear in diabetes or under high-glucose (HG) condition. Using an in vitro model of hyperglycemia in human umbilical vein endothelial cells (HUVECs), we found that Nar administration markedly attenuated HG-induced alterations of endothelial function, evidenced by the mitigation of oxidative stress and inflammation, the reduction of cell adhesion molecular expressions, and the improvement of insulin resistance. We also found that HG exposure significantly reduced the levels of intracellular heat shock protein 70 (iHSP70 or iHSPA1A) and the release of HSP70 from HUVECs. HSP70 depletion mimicked and clearly diminished the protective effects of Nar on HG-induced alterations of endothelial function. In addition, Nar treatment significantly enhanced iHSP70 protein levels through a transcription-dependent manner. These results demonstrated that Nar could protect HUVECs against HG-induced alterations of endothelial function through upregulating iHSP70 protein levels. These findings are also helpful in providing new therapeutic strategies that are promising in the clinical use of Nar for the treatment of diabetes and diabetic complications.
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Affiliation(s)
- Zhihan Zhang
- Department of Orthopaedic Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Hui Liu
- Department of Orthopaedic Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Xiang Hu
- Department of Orthopaedic Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Yikang He
- Tongji Medical College Huazhong University of Science and Technology, School of Nursing, Wuhan 430030, China
| | - Lu Li
- Department of Pathology and Pathophysiology, Wuhan University Taikang Medical School (School of Basic Medical Sciences), Wuhan 430071, China
| | - Xinyu Yang
- Department of Pathology and Pathophysiology, Wuhan University Taikang Medical School (School of Basic Medical Sciences), Wuhan 430071, China
| | - Changhua Wang
- Department of Pathology and Pathophysiology, Wuhan University Taikang Medical School (School of Basic Medical Sciences), Wuhan 430071, China
| | - Mingbai Hu
- Department of Breast and Thyroid Surgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Shengxiang Tao
- Department of Orthopaedic Trauma and Microsurgery, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
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11
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Scrimieri R, Cazzaniga A, Castiglioni S, Maier JAM. Vitamin D Prevents High Glucose-Induced Lipid Droplets Accumulation in Cultured Endothelial Cells: The Role of Thioredoxin Interacting Protein. Biomedicines 2021; 9:1874. [PMID: 34944690 PMCID: PMC8698366 DOI: 10.3390/biomedicines9121874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 12/04/2021] [Accepted: 12/06/2021] [Indexed: 12/21/2022] Open
Abstract
Vitamin D (VitD) exerts protective effects on the endothelium, which is fundamental for vascular integrity, partly by inhibiting free radical formation. We found that VitD prevents high glucose-induced Thioredoxin Interacting Protein (TXNIP) upregulation. Increased amounts of TXNIP are responsible for the accumulation of reactive oxygen species and, as a consequence, of lipid droplets. This is associated with increased amounts of triglycerides as the result of increased lipogenesis and reduced fatty acid oxidation. Remarkably, VitD rebalances the redox equilibrium, restores normal lipid content, and prevents the accumulation of lipid droplets. Our results highlight TXNIP as one of the targets of VitD in high glucose-cultured endothelial cells and shed some light on the protective effect of VitD on the endothelium.
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Affiliation(s)
- Roberta Scrimieri
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università di Milano, 20157 Milano, Italy; (A.C.); (S.C.); (J.A.M.M.)
| | - Alessandra Cazzaniga
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università di Milano, 20157 Milano, Italy; (A.C.); (S.C.); (J.A.M.M.)
| | - Sara Castiglioni
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università di Milano, 20157 Milano, Italy; (A.C.); (S.C.); (J.A.M.M.)
| | - Jeanette A. M. Maier
- Department of Biomedical and Clinical Sciences “Luigi Sacco”, Università di Milano, 20157 Milano, Italy; (A.C.); (S.C.); (J.A.M.M.)
- Interdisciplinary Centre for Nanostructured Materials and Interfaces (CIMaINa), Università di Milano, 20133 Milano, Italy
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12
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Ozyel B, Le Gall G, Needs PW, Kroon PA. Anti-Inflammatory Effects of Quercetin on High-Glucose and Pro-Inflammatory Cytokine Challenged Vascular Endothelial Cell Metabolism. Mol Nutr Food Res 2021; 65:e2000777. [PMID: 33481349 PMCID: PMC8614122 DOI: 10.1002/mnfr.202000777] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 12/09/2020] [Indexed: 12/15/2022]
Abstract
SCOPE Pro-inflammatory stimuli such as hyperglycemia and cytokines have been shown to negatively affect endothelial cell functions. The aim of this study is to assess the potential of quercetin and its human metabolites to overcome the deleterious effects of hyperglycemic or inflammatory conditions on the vascular endothelium by modulating endothelial cell metabolism. METHODS AND RESULTS A metabolomics approach enabled identification and quantification of 27 human umbilical vein endothelial cell (HUVEC) metabolites. Treatment of HUVECs with high-glucose concentrations causes significant increases in lactate and glutamate concentrations. Quercetin inhibits glucose-induced increases in lactate and adenosine 5'-triphosphate (ATP) and also increased inosine concentrations. Tumor necrosis factor α-treatment (TNFα) of HUVECs causes increases in asparagine and decreases in aspartate concentrations. Co-treatment with quercetin reduces pyruvate concentrations compared to TNFα-only treated controls. Subsequently, it was shown that quercetin and its HUVEC phase-2 conjugates inhibit adenosine deaminase, xanthine oxidase and 5'nucleotidase (CD73) but not ectonucleoside triphosphate diphosphohydrolase-1 (CD39) or purine nucleoside phosphorylase activities. CONCLUSION Quercetin was shown to alter the balance of HUVEC metabolites towards a less inflamed phenotype, both alone and in the presence of pro-inflammatory stimuli. These changes are consistent with the inhibition of particular enzymes involved in purine metabolism by quercetin and its HUVEC metabolites.
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Affiliation(s)
- Besim Ozyel
- Nutrition and Dietetics DepartmentEuropean University of LefkeLefke, Northern Cyprus, TR‐10Mersin9910Turkey
| | - Gwénaëlle Le Gall
- Norwich Medical SchoolUniversity of East AngliaBob Champion Research and Education Building, James Watson Road, Norwich Research ParkNorwichNR4 7UQUK
| | - Paul W. Needs
- Quadram Institute BioscienceNorwich Research ParkNorwichNR4 7UQUK
| | - Paul A. Kroon
- Quadram Institute BioscienceNorwich Research ParkNorwichNR4 7UQUK
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13
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Trans-endothelial trafficking of metabolic substrates and its importance in cardio-metabolic disease. Biochem Soc Trans 2021; 49:507-517. [PMID: 33616631 DOI: 10.1042/bst20200991] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 11/17/2022]
Abstract
The endothelium acts as a gatekeeper, controlling the movement of biomolecules between the circulation and underlying tissues. Although conditions of metabolic stress are traditionally considered as causes of endothelial dysfunction, a principal driver of cardiovascular disease, accumulating evidence suggests that endothelial cells are also active players in maintaining local metabolic homeostasis, in part, through regulating the supply of metabolic substrates, including lipids and glucose, to energy-demanding organs. Therefore, endothelial dysfunction, in terms of altered trans-endothelial trafficking of these substrates, may in fact be an early contributor towards the establishment of metabolic dysfunction and subsequent cardiovascular disease. Understanding the molecular mechanisms that underpin substrate trafficking through the endothelium represents an important area within the vascular and metabolism fields that may offer an opportunity for identifying novel therapeutic targets. This mini-review summarises the emerging mechanisms regulating the trafficking of lipids and glucose through the endothelial barrier and how this may impact on the development of cardio-metabolic disease.
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14
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Tumova S, Shi Y, Carr IM, Williamson G. Effects of quercetin and metabolites on uric acid biosynthesis and consequences for gene expression in the endothelium. Free Radic Biol Med 2021; 162:191-201. [PMID: 33091574 DOI: 10.1016/j.freeradbiomed.2020.10.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/12/2020] [Accepted: 10/16/2020] [Indexed: 12/18/2022]
Abstract
BACKGROUND Uric acid, a metabolic product of purine degradation in humans, is a risk factor for developing gout and type 2 diabetes, and supplementation with quercetin lowers plasma uric acid in mildly hyperuricemic men. Here we examined the mechanism of inhibition of enzymes involved in uric acid metabolism by quercetin, conjugates and microbial catabolites, and measured the effect of lowered circulating uric acid on endothelial cell gene expression. METHODS Inhibition of adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP) and xanthine oxidoreductase (XOR) activity by quercetin and metabolites was determined by HPLC. Human umbilical vein endothelial cells (HUVECs) were cultured under conditions mimicking blood flow, treated with uric acid (0, 300 or 500 μmol/L), and changes in gene expression measured using transcriptomics and quantitative droplet digital PCR. RESULTS In human plasma, no inhibition of PNP activity was observed, and only quercetin weakly inhibited ADA. XOR was not present at sufficient amount in human plasma to use for testing, but quercetin, quercetin-3'-sulfate and the gut microbial metabolite 3',4'-dihydroxyphenylacetic acid inhibited bovine milk XOR. Several changes were observed in gene expression in HUVECs under flow compared to static conditions, but after uric acid treatment, only very few changes were detected. CONCLUSIONS We propose that the main mechanism by which quercetin, as quercetin-3'-sulfate, lowers uric acid in vivo is through inhibition of XOR, and not ADA nor PNP. The pertinent shift in uric acid concentration was not sufficient to produce significant changes in endothelial gene expression in a cell model.
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Affiliation(s)
- Sarka Tumova
- University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Yuanlu Shi
- University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Ian M Carr
- University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Gary Williamson
- University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK; Department of Nutrition, Dietetics and Food, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, BASE Facility, 264 Ferntree Gully Road, Notting Hill, VIC, 3168, Australia.
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15
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Mamun AA, Hayashi H, Yamamura A, Nayeem MJ, Sato M. Hypoxia induces the translocation of glucose transporter 1 to the plasma membrane in vascular endothelial cells. J Physiol Sci 2020; 70:44. [PMID: 32962633 PMCID: PMC10717486 DOI: 10.1186/s12576-020-00773-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 09/11/2020] [Indexed: 12/22/2022]
Abstract
Glucose uptake and adenosine triphosphate (ATP) generation are important for the survival and growth of endothelial cells. An increase of glucose uptake under hypoxia was previously shown to be associated with the increased expression of glucose transporters (GLUTs). However, the regulation of GLUT trafficking to the cell surface has not been examined in detail. Here, we report the characterization of GLUT1 translocation to the plasma membrane during hypoxia in endothelial cells. Human umbilical vein endothelial cells (HUVECs) were exposed to hypoxia (1% O2) for 12 h, which significantly induced GLUT1 expression and translocation to the plasma membrane. GLUT1 translocation was associated with a decrease of intracellular ATP by hypoxia. Decreasing ATP levels with antimycin-A and 2-deoxyglucose induced GLUT1 translocation under normoxia. The induction of hypoxia-inducible factor-1α under normoxia did not influence the cell surface expression of GLUT1 or cellular ATP concentration. Interestingly, the translocation of GLUT1 induced by hypoxia was inhibited by the ATP-sensitive potassium (KATP) channel inhibitor glibenclamide, while the mitochondrial KATP channel inhibitor 5-HD did not influence GLUT1 translocation during hypoxia. These observations indicate that a decrease of intracellular ATP triggers GLUT1 translocation to the plasma membrane and is mediated by KATP channels, which would contribute to glucose uptake in HUVECs during hypoxia.
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Affiliation(s)
- Abdullah Al Mamun
- Department of Physiology, Aichi Medical University, 1-1 Yazako-Karimata, Nagakute-City, Aichi, 4801165, Japan
- Department of Biochemistry and Molecular Biology, Mawlana Bhashani Science and Technology University, Santosh, Tangail, 1902, Bangladesh
| | - Hisaki Hayashi
- Department of Physiology, Aichi Medical University, 1-1 Yazako-Karimata, Nagakute-City, Aichi, 4801165, Japan
| | - Aya Yamamura
- Department of Physiology, Aichi Medical University, 1-1 Yazako-Karimata, Nagakute-City, Aichi, 4801165, Japan
| | - Md Junayed Nayeem
- Department of Physiology, Aichi Medical University, 1-1 Yazako-Karimata, Nagakute-City, Aichi, 4801165, Japan
| | - Motohiko Sato
- Department of Physiology, Aichi Medical University, 1-1 Yazako-Karimata, Nagakute-City, Aichi, 4801165, Japan.
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16
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Holman GD. Structure, function and regulation of mammalian glucose transporters of the SLC2 family. Pflugers Arch 2020; 472:1155-1175. [PMID: 32591905 PMCID: PMC7462842 DOI: 10.1007/s00424-020-02411-3] [Citation(s) in RCA: 103] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 05/27/2020] [Accepted: 05/29/2020] [Indexed: 12/12/2022]
Abstract
The SLC2 genes code for a family of GLUT proteins that are part of the major facilitator superfamily (MFS) of membrane transporters. Crystal structures have recently revealed how the unique protein fold of these proteins enables the catalysis of transport. The proteins have 12 transmembrane spans built from a replicated trimer substructure. This enables 4 trimer substructures to move relative to each other, and thereby alternately opening and closing a cleft to either the internal or the external side of the membrane. The physiological substrate for the GLUTs is usually a hexose but substrates for GLUTs can include urate, dehydro-ascorbate and myo-inositol. The GLUT proteins have varied physiological functions that are related to their principal substrates, the cell type in which the GLUTs are expressed and the extent to which the proteins are associated with subcellular compartments. Some of the GLUT proteins translocate between subcellular compartments and this facilitates the control of their function over long- and short-time scales. The control of GLUT function is necessary for a regulated supply of metabolites (mainly glucose) to tissues. Pathophysiological abnormalities in GLUT proteins are responsible for, or associated with, clinical problems including type 2 diabetes and cancer and a range of tissue disorders, related to tissue-specific GLUT protein profiles. The availability of GLUT crystal structures has facilitated the search for inhibitors and substrates and that are specific for each GLUT and that can be used therapeutically. Recent studies are starting to unravel the drug targetable properties of each of the GLUT proteins.
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Affiliation(s)
- Geoffrey D Holman
- Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY, UK.
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17
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Tumova S, Houghton MJ, Williamson G. The effect of quercetin on endothelial cells is modified by heterocellular interactions. Food Funct 2020; 11:3916-3925. [PMID: 32363357 DOI: 10.1039/d0fo00141d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Single cell-type models are useful for determining mechanisms, but in vivo, cell-cell interactions are important, and neighbouring cells can impact endothelial cell function. Quercetin can attenuate endothelial dysfunction by modulating vascular tone and reducing inflammation. We determined the effect of quercetin on a co-culture between Human Umbilical Vein Endothelial Cells (HUVEC) and human HepG2 hepatic cells or human LHCN-M2 muscle cells. Heme oxygenase-1 (HO-1) mRNA and protein were decreased, pyruvate dehydrogenase kinase (PDK) 4 and glucose transporter (GLUT) 3 mRNA increased, and GLUT1 protein decreased in HUVEC when cultured with HepG2. GLUT transporters, but not the other targets, were similarly regulated in co-culture with muscle cells. Some but not all of the effects were mediated by lactate and transforming growth factor β1. Quercetin added apically to the endothelial cells upregulated HO-1 and downregulated PDK4 both in monoculture and in co-culture, but the total PDK4 levels were higher in the presence of HepG2 cells. In the absence of general permeability changes, glucose transport across the endothelial monolayer was elevated in the presence of HepG2 cells, however this effect was moderated by quercetin applied on the apical side of the endothelial cells. At lower glucose concentration, apical quercetin also promoted glucose uptake in HepG2 cells. Co-culturing HUVEC with the HepG2 cells showed capacity to modulate quercetin-elicited changes in endothelial gene transcription and glucose transport.
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18
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Tumova S, Kerimi A, Williamson G. Long term treatment with quercetin in contrast to the sulfate and glucuronide conjugates affects HIF1α stability and Nrf2 signaling in endothelial cells and leads to changes in glucose metabolism. Free Radic Biol Med 2019; 137:158-168. [PMID: 31029788 DOI: 10.1016/j.freeradbiomed.2019.04.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 04/17/2019] [Accepted: 04/18/2019] [Indexed: 01/08/2023]
Abstract
Endothelial functionality profoundly contributes to cardiovascular health. The effects of flavonoids shown to improve endothelial performance include regulating blood pressure by modulating endothelial nitric oxide synthase and NADPH oxidases, but their impact on glucose uptake and metabolism has not been explored. We treated human umbilical vein endothelial cells (HUVEC) with the flavonoid quercetin and its circulating metabolites acutely and chronically, then assessed glucose uptake, glucose metabolism, gene transcription and protein expression. Acute treatment had no effect on glucose uptake, ruling out any direct interaction with sugar transporters. Long term treatment with quercetin, but not quercetin 3-O-glucuronide or 3'-O-sulfate, significantly increased glucose uptake. Heme oxygenase-1 (HO-1) was induced by quercetin but not its conjugates, but was not implicated in the glucose uptake stimulation since hemin, a classical inducer of HO-1, did not affect glucose metabolism. Quercetin increased stability of the transcription factor hypoxia induced factor 1α (HIF1α), a powerful stimulant of glucose metabolism, which was also paralleled by treatment with a prolyl-4-hydroxylase inhibitor dimethyloxalylglycine (DMOG). 6-Phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), which regulates the rate of glycolysis, was upregulated by both quercetin and DMOG. Pyruvate dehydrogenase kinase (PDK) isoforms regulate pyruvate dehydrogenase; PDK2 and PDK4 were down-regulated by both effectors, but only DMOG also upregulated PDK1 and PDK3. Quercetin, but not DMOG, increased glucose-6-phosphate dehydrogenase. Chronic quercetin treatment also stimulated glucose transport across the HUVEC monolyer in a 3D culture model. Gene expression of several flavonoid transporters was repressed by quercetin, but this was either abolished (Organic anion transporter polypeptide 4C1) or reversed (Multidrug resistance gene 1) by both conjugates. We conclude that quercetin and its circulating metabolites differentially modulate glucose uptake/metabolism in endothelial cells, through effects on HIF1α and transcriptional regulation of energy metabolism.
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Affiliation(s)
- Sarka Tumova
- School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK
| | - Asimina Kerimi
- School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK
| | - Gary Williamson
- School of Food Science and Nutrition, University of Leeds, Leeds, LS2 9JT, UK; Department of Nutrition, Dietetics and Food, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, Notting Hill BASE Facility, 264 Ferntree Gully Road, Notting Hill, VIC, 3168, Australia.
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19
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Behnammanesh G, Durante ZE, Peyton KJ, Martinez-Lemus LA, Brown SM, Bender SB, Durante W. Canagliflozin Inhibits Human Endothelial Cell Proliferation and Tube Formation. Front Pharmacol 2019; 10:362. [PMID: 31057401 PMCID: PMC6477081 DOI: 10.3389/fphar.2019.00362] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 03/22/2019] [Indexed: 12/13/2022] Open
Abstract
Recent clinical trials revealed that sodium-glucose co-transporter 2 (SGLT2) inhibitors significantly reduce cardiovascular events in type 2 diabetic patients, however, canagliflozin increased limb amputations, an effect not seen with other SGLT2 inhibitors. Since endothelial cell (EC) dysfunction promotes diabetes-associated vascular disease and limb ischemia, we hypothesized that canagliflozin, but not other SGLT2 inhibitors, impairs EC proliferation, migration, and angiogenesis. Treatment of human umbilical vein ECs (HUVECs) with clinically relevant concentrations of canagliflozin, but not empagliflozin or dapagliflozin, inhibited cell proliferation. In particular, 10 μM canagliflozin reduced EC proliferation by approximately 45%. The inhibition of EC growth by canagliflozin occurred in the absence of cell death and was associated with diminished DNA synthesis, cell cycle arrest, and a striking decrease in cyclin A expression. Restoration of cyclin A expression via adenoviral-mediated gene transfer partially rescued the proliferative response of HUVECs treated with canagliflozin. A high concentration of canagliflozin (50 μM) modestly inhibited HUVEC migration by 20%, but markedly attenuated their tube formation by 65% and EC sprouting from mouse aortas by 80%. A moderate 20% reduction in HUVEC migration was also observed with a high concentration of empagliflozin (50 μM), while neither empagliflozin nor dapagliflozin affected tube formation by HUVECs. The present study identified canagliflozin as a robust inhibitor of human EC proliferation and tube formation. The anti-proliferative action of canagliflozin occurs in the absence of cell death and is due, in part, to the blockade of cyclin A expression. Notably, these actions are not seen with empagliflozin or dapagliflozin. The ability of canagliflozin to exert these pleiotropic effects on ECs may contribute to the clinical actions of this drug.
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Affiliation(s)
- Ghazaleh Behnammanesh
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, United States
| | - Zane E. Durante
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, United States
| | - Kelly J. Peyton
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, United States
| | - Luis A. Martinez-Lemus
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, United States
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, United States
| | - Scott M. Brown
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, United States
- Biomedical Sciences, University of Missouri, Columbia, MO, United States
| | - Shawn B. Bender
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO, United States
- Research Service, Harry S. Truman Memorial Veterans Hospital, Columbia, MO, United States
- Biomedical Sciences, University of Missouri, Columbia, MO, United States
| | - William Durante
- Department of Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, United States
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20
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Houghton MJ, Kerimi A, Tumova S, Boyle JP, Williamson G. Quercetin preserves redox status and stimulates mitochondrial function in metabolically-stressed HepG2 cells. Free Radic Biol Med 2018; 129:296-309. [PMID: 30266680 DOI: 10.1016/j.freeradbiomed.2018.09.037] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 09/18/2018] [Accepted: 09/23/2018] [Indexed: 01/15/2023]
Abstract
Hyperglycemia augments formation of intracellular reactive oxygen species (ROS) with associated mitochondrial damage and increased risk of insulin resistance in type 2 diabetes. We examined whether quercetin could reverse chronic high glucose-induced oxidative stress and mitochondrial dysfunction. Following long-term high glucose treatment, complex I activity was significantly decreased in isolated mitochondria from HepG2 cells. Quercetin dose-dependently recovered complex I activity and lowered cellular ROS generation under both high and normal glucose conditions. Respirometry studies showed that quercetin could counteract the detrimental increase in inner mitochondrial membrane proton leakage resulting from high glucose while it increased oxidative respiration, despite a decrease in electron transfer system (ETS) capacity, and lower non-ETS oxygen consumption. A quercetin-stimulated increase in cellular NAD+/NADH was evident within 2 h and a two-fold increase in PGC-1α mRNA within 6 h, in both normal and high glucose conditions. A similar pattern was also found for the mRNA expression of the repulsive guidance molecule b (RGMB) and its long non-coding RNA (lncRNA) RGMB-AS1 with quercetin, indicating a potential change of the glycolytic phenotype and suppression of aberrant cellular growth which is characteristic of the HepG2 cells. Direct effects of quercetin on PGC-1α activity were minimal, as quercetin only weakly enhanced PGC-1α binding to PPARα in vitro at higher concentrations. Our results suggest that quercetin may protect mitochondrial function from high glucose-induced stress by increasing cellular NAD+/NADH and activation of PGC-1α-mediated pathways. Lower ROS in combination with improved complex I activity and ETS coupling efficiency under conditions of amplified oxidative stress could reinforce mitochondrial integrity and improve redox status, beneficial in certain metabolic diseases.
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Affiliation(s)
- Michael J Houghton
- School of Food Science and Nutrition, Faculty of Maths and Physical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Asimina Kerimi
- School of Food Science and Nutrition, Faculty of Maths and Physical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Sarka Tumova
- School of Food Science and Nutrition, Faculty of Maths and Physical Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - John P Boyle
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - Gary Williamson
- School of Food Science and Nutrition, Faculty of Maths and Physical Sciences, University of Leeds, Leeds LS2 9JT, UK.
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21
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Mancini SJ, Boyd D, Katwan OJ, Strembitska A, Almabrouk TA, Kennedy S, Palmer TM, Salt IP. Canagliflozin inhibits interleukin-1β-stimulated cytokine and chemokine secretion in vascular endothelial cells by AMP-activated protein kinase-dependent and -independent mechanisms. Sci Rep 2018; 8:5276. [PMID: 29588466 PMCID: PMC5869674 DOI: 10.1038/s41598-018-23420-4] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 03/12/2018] [Indexed: 12/16/2022] Open
Abstract
Recent clinical trials of the hypoglycaemic sodium-glucose co-transporter-2 (SGLT2) inhibitors, which inhibit renal glucose reabsorption, have reported beneficial cardiovascular outcomes. Whether SGLT2 inhibitors directly affect cardiovascular tissues, however, remains unclear. We have previously reported that the SGLT2 inhibitor canagliflozin activates AMP-activated protein kinase (AMPK) in immortalised cell lines and murine hepatocytes. As AMPK has anti-inflammatory actions in vascular cells, we examined whether SGLT2 inhibitors attenuated inflammatory signalling in cultured human endothelial cells. Incubation with clinically-relevant concentrations of canagliflozin, but not empagliflozin or dapagliflozin activated AMPK and inhibited IL-1β-stimulated adhesion of pro-monocytic U937 cells and secretion of IL-6 and monocyte chemoattractant protein-1 (MCP-1). Inhibition of MCP-1 secretion was attenuated by expression of dominant-negative AMPK and was mimicked by the direct AMPK activator, A769662. Stimulation of cells with either canagliflozin or A769662 had no effect on IL-1β-stimulated cell surface levels of adhesion molecules or nuclear factor-κB signalling. Despite these identical effects of canagliflozin and A769662, IL-1β-stimulated IL-6/MCP-1 mRNA was inhibited by canagliflozin, but not A769662, whereas IL-1β-stimulated c-jun N-terminal kinase phosphorylation was inhibited by A769662, but not canagliflozin. These data indicate that clinically-relevant canagliflozin concentrations directly inhibit endothelial pro-inflammatory chemokine/cytokine secretion by AMPK-dependent and -independent mechanisms without affecting early IL-1β signalling.
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Affiliation(s)
- Sarah J Mancini
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Daria Boyd
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Omar J Katwan
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
- Department of Biochemistry, College of Medicine, University of Diyala, Baqubah, Iraq
| | - Anastasiya Strembitska
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Tarek A Almabrouk
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
- Medical School, University of Zawia, Zawia, Libya
| | - Simon Kennedy
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Timothy M Palmer
- School of Pharmacy and Medical Sciences, University of Bradford, Bradford, West Yorkshire, BD7 1DP, UK
| | - Ian P Salt
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
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22
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Garrigue P, Bodin-Hullin A, Balasse L, Fernandez S, Essamet W, Dignat-George F, Pacak K, Guillet B, Taïeb D. The Evolving Role of Succinate in Tumor Metabolism: An 18F-FDG-Based Study. J Nucl Med 2017; 58:1749-1755. [PMID: 28619735 DOI: 10.2967/jnumed.117.192674] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 05/24/2017] [Indexed: 12/27/2022] Open
Abstract
In recent years, inherited and acquired mutations in the tricarboxylic acid (TCA) cycle enzymes have been reported in diverse cancers. Pheochromocytomas and paragangliomas often exhibit dysregulation of glucose metabolism, which is also driven by mutations in genes encoding the TCA cycle enzymes or by activation of hypoxia signaling. Pheochromocytomas and paragangliomas associated with succinate dehydrogenase (SDH) deficiency are characterized by high 18F-FDG avidity. This association is currently only partially explained. Therefore, we hypothesized that accumulation of succinate due to the TCA cycle defect could be the major connecting hub between SDH-mutated tumors and the 18F-FDG uptake profile. Methods: To test whether succinate modifies the 18F-FDG metabolic profile of tumors, we performed in vitro and in vivo (small-animal PET/CT imaging and autoradiography) experiments in the presence of succinate, fumarate, and phosphate-buffered saline (PBS) in different cell models. As a control, we also evaluated the impact of succinate on 18F-fluorocholine uptake and retention. Glucose transporter 1 (GLUT1) immunohistochemistry was performed to assess whether 18F-FDG uptake correlates with GLUT1 staining. Results: Intratumoral injection of succinate significantly increased 18F-FDG uptake at 24 h on small-animal PET/CT imaging and autoradiography. No effect of succinate was observed on cancer cells in vitro, but interestingly, we found that succinate caused increased 18F-FDG uptake by human umbilical vein endothelial cells in a concentration-dependent manner. No significant effect was observed after intratumoral injection of fumarate or PBS. Succinate, fumarate, and PBS have no effect on cell viability, regardless of cell lineage. Intramuscular injection of succinate also significantly increases 18F-FDG uptake by muscle when compared with either PBS or fumarate, highlighting the effect of succinate on connective tissues. No difference was observed between PBS and succinate on 18F-fluorocholine uptake in the tumor and muscle and on hind limb blood flow. GLUT1 expression quantification did not significantly differ between the study groups. Conclusion: The present study shows that succinate stimulates 18F-FDG uptake by endothelial cells, a finding that partially explains the 18F-FDG metabotype observed in tumors with SDH deficiency. Although this study is an 18F-FDG-based approach, it provides an impetus to better characterize the determinants of 18F-FDG uptake in various tumors and their surrounding microenvironment, with a special emphasis on the role of tumor-specific oncometabolites.
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Affiliation(s)
- Philippe Garrigue
- Aix-Marseille University, INSERM, UMR-S 1076, Marseille, France.,Aix-Marseille University, CERIMED, Marseille, France.,Department of Nuclear Medicine, Aix-Marseille University, Marseille, France
| | | | - Laure Balasse
- Aix-Marseille University, INSERM, UMR-S 1076, Marseille, France.,Aix-Marseille University, CERIMED, Marseille, France
| | | | - Wassim Essamet
- Department of Neuropathology, APHM Timone, Marseille, France; and
| | | | - Karel Pacak
- Section on Medical Neuroendocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Benjamin Guillet
- Aix-Marseille University, INSERM, UMR-S 1076, Marseille, France.,Aix-Marseille University, CERIMED, Marseille, France.,Department of Nuclear Medicine, Aix-Marseille University, Marseille, France
| | - David Taïeb
- Aix-Marseille University, CERIMED, Marseille, France .,Department of Nuclear Medicine, Aix-Marseille University, Marseille, France
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