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Barahona MJ, Ferrada L, Vera M, Nualart F. Tanycytes release glucose using the glucose-6-phosphatase system during hypoglycemia to control hypothalamic energy balance. Mol Metab 2024; 84:101940. [PMID: 38641253 PMCID: PMC11060961 DOI: 10.1016/j.molmet.2024.101940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/09/2024] [Accepted: 04/09/2024] [Indexed: 04/21/2024] Open
Abstract
OBJECTIVE The liver releases glucose into the blood using the glucose-6-phosphatase (G6Pase) system, a multiprotein complex located in the endoplasmic reticulum (ER). Here, we show for the first time that the G6Pase system is also expressed in hypothalamic tanycytes, and it is required to regulate energy balance. METHODS Using automatized qRT-PCR and immunohistochemical analyses, we evaluated the expression of the G6Pase system. Fluorescent glucose analogue (2-NBDG) uptake was evaluated by 4D live-cell microscopy. Glucose release was tested using a glucose detection kit and high-content live-cell analysis instrument, Incucyte s3. In vivo G6pt knockdown in tanycytes was performed by AAV1-shG6PT-mCherry intracerebroventricular injection. Body weight gain, adipose tissue weight, food intake, glucose metabolism, c-Fos, and neuropeptide expression were evaluated at 4 weeks post-transduction. RESULTS Tanycytes sequester glucose-6-phosphate (G6P) into the ER through the G6Pase system and release glucose in hypoglycaemia via facilitative glucose transporters (GLUTs). Strikingly, in vivo tanycytic G6pt knockdown has a powerful peripheral anabolic effect observed through decreased body weight, white adipose tissue (WAT) tissue mass, and strong downregulation of lipogenesis genes. Selective deletion of G6pt in tanycytes also decreases food intake, c-Fos expression in the arcuate nucleus (ARC), and Npy mRNA expression in fasted mice. CONCLUSIONS The tanycyte-associated G6Pase system is a central mechanism involved in controlling metabolism and energy balance.
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Affiliation(s)
- María José Barahona
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile; Center for Advanced Microscopy CMA BIO BIO, University of Concepcion, Concepcion, Chile; Laboratory of Appetite Physiology (FIDELA), Faculty of Medicine and Sciences, University San Sebastián, Concepción Campus, Concepción, Chile
| | - Luciano Ferrada
- Center for Advanced Microscopy CMA BIO BIO, University of Concepcion, Concepcion, Chile
| | - Matías Vera
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile; Center for Advanced Microscopy CMA BIO BIO, University of Concepcion, Concepcion, Chile
| | - Francisco Nualart
- Laboratory of Neurobiology and Stem Cells, NeuroCellT, Department of Cellular Biology, Faculty of Biological Sciences, University of Concepcion, Concepcion, Chile; Center for Advanced Microscopy CMA BIO BIO, University of Concepcion, Concepcion, Chile.
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2
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Wang T, Tian X, Kim HB, Jang Y, Huang Z, Na CH, Wang J. Intracellular energy controls dynamics of stress-induced ribonucleoprotein granules. Nat Commun 2022; 13:5584. [PMID: 36151083 PMCID: PMC9508253 DOI: 10.1038/s41467-022-33079-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 08/26/2022] [Indexed: 12/13/2022] Open
Abstract
Energy metabolism and membraneless organelles have been implicated in human diseases including neurodegeneration. How energy deficiency regulates ribonucleoprotein particles such as stress granules (SGs) is still unclear. Here we identified a unique type of granules induced by energy deficiency under physiological conditions and uncovered the mechanisms by which the dynamics of diverse stress-induced granules are regulated. Severe energy deficiency induced the rapid formation of energy deficiency-induced stress granules (eSGs) independently of eIF2α phosphorylation, whereas moderate energy deficiency delayed the clearance of conventional SGs. The formation of eSGs or the clearance of SGs was regulated by the mTOR-4EBP1-eIF4E pathway or eIF4A1, involving assembly of the eIF4F complex or RNA condensation, respectively. In neurons or brain organoids derived from patients carrying the C9orf72 repeat expansion associated with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), the eSG formation was enhanced, and the clearance of conventional SGs was impaired. These results reveal a critical role for intracellular energy in the regulation of diverse granules and suggest that disruptions in energy-controlled granule dynamics may contribute to the pathogenesis of relevant diseases. Stress granules are associated with neurodegenerative diseases. Here, Wang et al. found intracellular energy deficiencies trigger a unique type of granules and disrupt granule disassembly through 4EBP1/eIF4A.
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Affiliation(s)
- Tao Wang
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21205, USA. .,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA.
| | - Xibin Tian
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21205, USA.,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Han Byeol Kim
- Department of Neurology, Institute for Cell Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Yura Jang
- Department of Neurology, Institute for Cell Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Zhiyuan Huang
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21205, USA.,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Chan Hyun Na
- Department of Neurology, Institute for Cell Engineering, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Jiou Wang
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, 21205, USA. .,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA.
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3
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The Succinate Receptor SUCNR1 Resides at the Endoplasmic Reticulum and Relocates to the Plasma Membrane in Hypoxic Conditions. Cells 2022; 11:cells11142185. [PMID: 35883628 PMCID: PMC9321536 DOI: 10.3390/cells11142185] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 07/08/2022] [Accepted: 07/09/2022] [Indexed: 12/24/2022] Open
Abstract
The GPCR SUCNR1/GPR91 exerts proangiogenesis upon stimulation with the Krebs cycle metabolite succinate. GPCR signaling depends on the surrounding environment and intracellular localization through location bias. Here, we show by microscopy and by cell fractionation that in neurons, SUCNR1 resides at the endoplasmic reticulum (ER), while being fully functional, as shown by calcium release and the induction of the expression of the proangiogenic gene for VEGFA. ER localization was found to depend upon N-glycosylation, particularly at position N8; the nonglycosylated mutant receptor localizes at the plasma membrane shuttled by RAB11. This SUCNR1 glycosylation is physiologically regulated, so that during hypoxic conditions, SUCNR1 is deglycosylated and relocates to the plasma membrane. Downstream signal transduction of SUCNR1 was found to activate the prostaglandin synthesis pathway through direct interaction with COX-2 at the ER; pharmacologic antagonism of the PGE2 EP4 receptor (localized at the nucleus) was found to prevent VEGFA expression. Concordantly, restoring the expression of SUCNR1 in the retina of SUCNR1-null mice renormalized vascularization; this effect is markedly diminished after transfection of the plasma membrane-localized SUCNR1 N8A mutant, emphasizing that ER localization of the succinate receptor is necessary for proper vascularization. These findings uncover an unprecedented physiologic process where GPCR resides at the ER for signaling function.
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4
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San Martín A, Arce-Molina R, Aburto C, Baeza-Lehnert F, Barros LF, Contreras-Baeza Y, Pinilla A, Ruminot I, Rauseo D, Sandoval PY. Visualizing physiological parameters in cells and tissues using genetically encoded indicators for metabolites. Free Radic Biol Med 2022; 182:34-58. [PMID: 35183660 DOI: 10.1016/j.freeradbiomed.2022.02.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 02/07/2023]
Abstract
The study of metabolism is undergoing a renaissance. Since the year 2002, over 50 genetically-encoded fluorescent indicators (GEFIs) have been introduced, capable of monitoring metabolites with high spatial/temporal resolution using fluorescence microscopy. Indicators are fusion proteins that change their fluorescence upon binding a specific metabolite. There are indicators for sugars, monocarboxylates, Krebs cycle intermediates, amino acids, cofactors, and energy nucleotides. They permit monitoring relative levels, concentrations, and fluxes in living systems. At a minimum they report relative levels and, in some cases, absolute concentrations may be obtained by performing ad hoc calibration protocols. Proper data collection, processing, and interpretation are critical to take full advantage of these new tools. This review offers a survey of the metabolic indicators that have been validated in mammalian systems. Minimally invasive, these indicators have been instrumental for the purposes of confirmation, rebuttal and discovery. We envision that this powerful technology will foster metabolic physiology.
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Affiliation(s)
- A San Martín
- Centro de Estudios Científicos (CECs), Valdivia, Chile.
| | - R Arce-Molina
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - C Aburto
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | | | - L F Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - Y Contreras-Baeza
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - A Pinilla
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - I Ruminot
- Centro de Estudios Científicos (CECs), Valdivia, Chile
| | - D Rauseo
- Centro de Estudios Científicos (CECs), Valdivia, Chile; Universidad Austral de Chile, Valdivia, Chile
| | - P Y Sandoval
- Centro de Estudios Científicos (CECs), Valdivia, Chile
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5
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Anjali A, Fatima U, Senthil-Kumar M. The ins and outs of SWEETs in plants: Current understanding of the basics and their prospects in crop improvement. J Biosci 2021. [DOI: 10.1007/s12038-021-00227-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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6
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Dvorak V, Wiedmer T, Ingles-Prieto A, Altermatt P, Batoulis H, Bärenz F, Bender E, Digles D, Dürrenberger F, Heitman LH, IJzerman AP, Kell DB, Kickinger S, Körzö D, Leippe P, Licher T, Manolova V, Rizzetto R, Sassone F, Scarabottolo L, Schlessinger A, Schneider V, Sijben HJ, Steck AL, Sundström H, Tremolada S, Wilhelm M, Wright Muelas M, Zindel D, Steppan CM, Superti-Furga G. An Overview of Cell-Based Assay Platforms for the Solute Carrier Family of Transporters. Front Pharmacol 2021; 12:722889. [PMID: 34447313 PMCID: PMC8383457 DOI: 10.3389/fphar.2021.722889] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 07/19/2021] [Indexed: 12/12/2022] Open
Abstract
The solute carrier (SLC) superfamily represents the biggest family of transporters with important roles in health and disease. Despite being attractive and druggable targets, the majority of SLCs remains understudied. One major hurdle in research on SLCs is the lack of tools, such as cell-based assays to investigate their biological role and for drug discovery. Another challenge is the disperse and anecdotal information on assay strategies that are suitable for SLCs. This review provides a comprehensive overview of state-of-the-art cellular assay technologies for SLC research and discusses relevant SLC characteristics enabling the choice of an optimal assay technology. The Innovative Medicines Initiative consortium RESOLUTE intends to accelerate research on SLCs by providing the scientific community with high-quality reagents, assay technologies and data sets, and to ultimately unlock SLCs for drug discovery.
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Affiliation(s)
- Vojtech Dvorak
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Tabea Wiedmer
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Alvaro Ingles-Prieto
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | | | - Helena Batoulis
- Drug Discovery Sciences–Lead Discovery, Bayer Pharmaceuticals, Wuppertal, Germany
| | - Felix Bärenz
- Sanofi-Aventis Deutschland GmbH, Frankfurt am Main, Germany
| | - Eckhard Bender
- Drug Discovery Sciences–Lead Discovery, Bayer Pharmaceuticals, Wuppertal, Germany
| | - Daniela Digles
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | | | - Laura H. Heitman
- Division of Drug Discovery and Safety, LACDR, Leiden University, Leiden, Netherlands
| | - Adriaan P. IJzerman
- Division of Drug Discovery and Safety, LACDR, Leiden University, Leiden, Netherlands
| | - Douglas B. Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
- Novo Nordisk Foundation Centre for Biosustainability, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Stefanie Kickinger
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Daniel Körzö
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Philipp Leippe
- Department of Chemical Biology, Max Planck Institute for Medical Research, Heidelberg, Germany
| | - Thomas Licher
- Sanofi-Aventis Deutschland GmbH, Frankfurt am Main, Germany
| | | | | | | | | | - Avner Schlessinger
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Vanessa Schneider
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | - Hubert J. Sijben
- Division of Drug Discovery and Safety, LACDR, Leiden University, Leiden, Netherlands
| | | | | | | | | | - Marina Wright Muelas
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Diana Zindel
- Drug Discovery Sciences–Lead Discovery, Bayer Pharmaceuticals, Wuppertal, Germany
| | - Claire M. Steppan
- Pfizer Worldwide Research, Development and Medical, Groton, MA, United States
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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7
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Keller JP, Marvin JS, Lacin H, Lemon WC, Shea J, Kim S, Lee RT, Koyama M, Keller PJ, Looger LL. In vivo glucose imaging in multiple model organisms with an engineered single-wavelength sensor. Cell Rep 2021; 35:109284. [PMID: 34161775 DOI: 10.1016/j.celrep.2021.109284] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 03/06/2020] [Accepted: 06/01/2021] [Indexed: 12/23/2022] Open
Abstract
Glucose is arguably the most important molecule in metabolism, and its dysregulation underlies diabetes. We describe a family of single-wavelength genetically encoded glucose sensors with a high signal-to-noise ratio, fast kinetics, and affinities varying over four orders of magnitude (1 μM to 10 mM). The sensors allow mechanistic characterization of glucose transporters expressed in cultured cells with high spatial and temporal resolution. Imaging of neuron/glia co-cultures revealed ∼3-fold faster glucose changes in astrocytes. In larval Drosophila central nervous system explants, intracellular neuronal glucose fluxes suggested a rostro-caudal transport pathway in the ventral nerve cord neuropil. In zebrafish, expected glucose-related physiological sequelae of insulin and epinephrine treatments were directly visualized. Additionally, spontaneous muscle twitches induced glucose uptake in muscle, and sensory and pharmacological perturbations produced large changes in the brain. These sensors will enable rapid, high-resolution imaging of glucose influx, efflux, and metabolism in behaving animals.
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Affiliation(s)
- Jacob P Keller
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
| | - Jonathan S Marvin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Haluk Lacin
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - William C Lemon
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Jamien Shea
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Soomin Kim
- Harvard Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard Medical School, Brigham and Women's Hospital, Cambridge, MA, USA
| | - Richard T Lee
- Harvard Department of Stem Cell and Regenerative Biology, Harvard Stem Cell Institute, Harvard Medical School, Brigham and Women's Hospital, Cambridge, MA, USA; The Cardiovascular Division, Department of Medicine, Harvard Medical School, Brigham and Women's Hospital, Cambridge, MA, USA
| | - Minoru Koyama
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Philipp J Keller
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Loren L Looger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA.
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8
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Breia R, Conde A, Badim H, Fortes AM, Gerós H, Granell A. Plant SWEETs: from sugar transport to plant-pathogen interaction and more unexpected physiological roles. PLANT PHYSIOLOGY 2021; 186:836-852. [PMID: 33724398 PMCID: PMC8195505 DOI: 10.1093/plphys/kiab127] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/05/2021] [Indexed: 05/19/2023]
Abstract
Sugars Will Eventually be Exported Transporters (SWEETs) have important roles in numerous physiological mechanisms where sugar efflux is critical, including phloem loading, nectar secretion, seed nutrient filling, among other less expected functions. They mediate low affinity and high capacity transport, and in angiosperms this family is composed by 20 paralogs on average. As SWEETs facilitate the efflux of sugars, they are highly susceptible to hijacking by pathogens, making them central players in plant-pathogen interaction. For instance, several species from the Xanthomonas genus are able to upregulate the transcription of SWEET transporters in rice (Oryza sativa), upon the secretion of transcription-activator-like effectors. Other pathogens, such as Botrytis cinerea or Erysiphe necator, are also capable of increasing SWEET expression. However, the opposite behavior has been observed in some cases, as overexpression of the tonoplast AtSWEET2 during Pythium irregulare infection restricted sugar availability to the pathogen, rendering plants more resistant. Therefore, a clear-cut role for SWEET transporters during plant-pathogen interactions has so far been difficult to define, as the metabolic signatures and their regulatory nodes, which decide the susceptibility or resistance responses, remain poorly understood. This fuels the still ongoing scientific question: what roles can SWEETs play during plant-pathogen interaction? Likewise, the roles of SWEET transporters in response to abiotic stresses are little understood. Here, in addition to their relevance in biotic stress, we also provide a small glimpse of SWEETs importance during plant abiotic stress, and briefly debate their importance in the particular case of grapevine (Vitis vinifera) due to its socioeconomic impact.
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Affiliation(s)
- Richard Breia
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga 4710-057, Portugal
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes e Alto Douro, Vila Real 5001-801, Portugal
| | - Artur Conde
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga 4710-057, Portugal
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes e Alto Douro, Vila Real 5001-801, Portugal
- Author for communication:
| | - Hélder Badim
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga 4710-057, Portugal
| | - Ana Margarida Fortes
- Lisbon Science Faculty, BioISI, University of Lisbon, Campo Grande, Lisbon 1749-016, Portugal
| | - Hernâni Gerós
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga 4710-057, Portugal
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes e Alto Douro, Vila Real 5001-801, Portugal
- Centre of Biological Engineering (CEB), Department of Engineering, University of Minho, Braga 4710-057, Portugal
| | - Antonio Granell
- Institute of Molecular and Cellular Biology of Plants, Spanish National Research Council (CSIC), Polytechnic University of Valencia, Valencia 46022, Spain
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9
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Sadoine M, Reger M, Wong KM, Frommer WB. Affinity Series of Genetically Encoded Förster Resonance Energy-Transfer Sensors for Sucrose. ACS Sens 2021; 6:1779-1784. [PMID: 33974799 DOI: 10.1021/acssensors.0c02495] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Genetically encoded fluorescent sugar sensors are valuable tools for the discovery of transporters and for quantitative monitoring of sugar steady-state levels in intact tissues. Genetically encoded Förster resonance energy-transfer sensors for glucose have been designed and optimized extensively, and a full series of affinity mutants is available for in vivo studies. However, to date, only a single improved sucrose sensor FLIPsuc-90μΔ1 with Km for sucrose of ∼90 μM was available. This sucrose sensor was engineered on the basis of an Agrobacterium tumefaciens sugar-binding protein. Here, we took a two-step approach to first improve the dynamic range of the FLIPsuc sensor and then expand the detection range from micro- to millimolar sucrose concentrations by mutating a key residue in the binding site. The resulting series of sucrose sensors may enable investigation of sucrose transporter candidates and comprehensive in vivo analyses of sucrose concentration in plants. Since FLIPsuc-90μ also detects trehalose in animal cells, the new series of sensors will likely be suitable for investigating trehalose transport and monitor trehalose steady-state levels in vivo.
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Affiliation(s)
- Mayuri Sadoine
- Institute for Molecular Physiology, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany
| | - Mira Reger
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, United States
| | - Ka Man Wong
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, United States
| | - Wolf B. Frommer
- Institute for Molecular Physiology, Heinrich Heine University Düsseldorf, Düsseldorf 40225, Germany
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305, United States
- Institute for Transformative Biomolecules, ITbM, Nagoya University, Nagoya, Aichi 464-8601, Japan
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10
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Datamining and functional environmental genomics reassess the phylogenetics and functional diversity of fungal monosaccharide transporters. Appl Microbiol Biotechnol 2021; 105:647-660. [PMID: 33394157 DOI: 10.1007/s00253-020-11076-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 12/14/2020] [Accepted: 12/23/2020] [Indexed: 10/22/2022]
Abstract
Sugar transporters are essential components of carbon metabolism and have been extensively studied to control sugar uptake by yeasts and filamentous fungi used in fermentation processes. Based on published information on characterized fungal sugar porters, we show that this protein family encompasses phylogenetically distinct clades. While several clades encompass transporters that seemingly specialized on specific "sugar-related" molecules (e.g., myo-inositol, charged sugar analogs), others include mostly either mono- or di/oligosaccharide low-specificity transporters. To address the issue of substrate specificity of sugar transporters, that protein primary sequences do not fully reveal, we screened "multi-species" soil eukaryotic cDNA libraries for mannose transporters, a sugar that had never been used to select transporters. We obtained 19 environmental transporters, mostly from Basidiomycota and Ascomycota. Among them, one belonged to the unusual "Fucose H+ Symporter" family, which is only known in Fungi for a rhamnose transporter in Aspergillus niger. Functional analysis of the 19 transporters by expression in yeast and for two of them in Xenopus laevis oocytes for electrophysiological measurements indicated that most of them showed a preference for D-mannose over other tested D-C6 (glucose, fructose, galactose) or D-C5 (xylose) sugars. For the several glucose and fructose-negative transporters, growth of the corresponding recombinant yeast strains was prevented on mannose in the presence of one of these sugars that may act by competition for the binding site. Our results highlight the potential of environmental genomics to figure out the functional diversity of key fungal protein families and that can be explored in a context of biotechnology. KEY POINTS: • Most fungal sugar transporters accept several sugars as substrates. • Transporters, belonging to 2 protein families, were isolated from soil cDNA libraries. • Environmental transporters featured novel substrate specificities.
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11
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Ren Y, Sun H, Zong M, Guo S, Ren Z, Zhao J, Li M, Zhang J, Tian S, Wang J, Yu Y, Gong G, Zhang H, He H, Li L, Zhang X, Liu F, Fei Z, Xu Y. Localization shift of a sugar transporter contributes to phloem unloading in sweet watermelons. THE NEW PHYTOLOGIST 2020; 227:1858-1871. [PMID: 32453446 DOI: 10.1111/nph.16659] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 04/26/2020] [Indexed: 05/15/2023]
Abstract
Unloading sugar from sink phloem by transporters is complex and much remains to be understood about this phenomenon in the watermelon fruit. Here, we report a novel vacuolar sugar transporter (ClVST1) identified through map-based cloning and association study, whose expression in fruit phloem is associated with accumulation of sucrose (Suc) in watermelon fruit. ClVST197 knockout lines show decreased sugar content and total biomass, whereas overexpression of ClVST197 increases Suc content. Population genomic and subcellular localization analyses strongly suggest a single-base change at the coding region of ClVST197 as a major molecular event during watermelon domestication, which results in the truncation of 45 amino acids and shifts the localization of ClVST197 to plasma membranes in sweet watermelons. Molecular, biochemical and phenotypic analyses indicate that ClVST197 is a novel sugar transporter for Suc and glucose efflux and unloading. Functional characterization of ClVST1 provides a novel strategy to increase sugar sink potency during watermelon domestication.
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Affiliation(s)
- Yi Ren
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Honghe Sun
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Mei Zong
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Shaogui Guo
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Zhijie Ren
- College of Life Sciences, Capital Normal University, Beijing, 100048, China
| | - Jianyu Zhao
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, MOE Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, Beijing, 100193, China
| | - Maoying Li
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Jie Zhang
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Shouwei Tian
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Jinfang Wang
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Yongtao Yu
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Guoyi Gong
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Haiying Zhang
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Hongju He
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Legong Li
- College of Life Sciences, Capital Normal University, Beijing, 100048, China
| | - Xiaolan Zhang
- Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, MOE Joint International Research Laboratory of Crop Molecular Breeding, China Agricultural University, Beijing, 100193, China
| | - Fan Liu
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
| | - Zhangjun Fei
- Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY, 14853, USA
- US Department of Agriculture-Agricultural Research Service, Robert W. Holley Center for Agriculture and Health, Ithaca, NY, 14853, USA
| | - Yong Xu
- National Watermelon and Melon Improvement Center, Beijing Academy of Agricultural and Forestry Sciences, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Beijing Key Laboratory of Vegetable Germplasm Improvement, Beijing, 100097, China
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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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Species-Specific Glucose-6-Phosphatase Activity in the Small Intestine-Studies in Three Different Mammalian Models. Int J Mol Sci 2019; 20:ijms20205039. [PMID: 31614497 PMCID: PMC6829527 DOI: 10.3390/ijms20205039] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 10/04/2019] [Accepted: 10/09/2019] [Indexed: 12/16/2022] Open
Abstract
Besides the liver, which has always been considered the major source of endogenous glucose production in all post-absorptive situations, kidneys and intestines can also produce glucose in blood, particularly during fasting and under protein feeding. However, observations gained in different experimental animals have given ambiguous results concerning the presence of the glucose-6-phosphatase system in the small intestine. The aim of this study was to better define the species-related differences of this putative gluconeogenic organ in glucose homeostasis. The components of the glucose-6-phosphatase system (i.e., glucose-6-phosphate transporter and glucose-6-phosphatase itself) were analyzed in homogenates or microsomal fractions prepared from the small intestine mucosae and liver of rats, guinea pigs, and humans. Protein and mRNA levels, as well as glucose-6-phosphatase activities, were detected. The results showed that the glucose-6-phosphatase system is poorly represented in the small intestine of rats; on the other hand, significant expressions of glucose-6-phosphate transporter and of the glucose-6-phosphatase were found in the small intestine of guinea pigs and homo sapiens. The activity of the recently described fructose-6-phosphate transporter–intraluminal hexose isomerase pathway was also present in intestinal microsomes from these two species. The results demonstrate that the gluconeogenic role of the small intestine is highly species-specific and presumably dependent on feeding behavior (e.g., fructose consumption) and the actual state of metabolism.
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ADP-dependent glucokinase regulates energy metabolism via ER-localized glucose sensing. Sci Rep 2019; 9:14248. [PMID: 31582762 PMCID: PMC6776650 DOI: 10.1038/s41598-019-50566-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Accepted: 09/05/2019] [Indexed: 12/21/2022] Open
Abstract
Modulation of energy metabolism to a highly glycolytic phenotype, i.e. Warburg effect, is a common phenotype of cancer and activated immune cells allowing increased biomass-production for proliferation and cell division. Endoplasmic reticulum (ER)-localized ADP-dependent glucokinase (ADPGK) has been shown to play a critical role in T cell receptor activation-induced remodeling of energy metabolism, however the underlying mechanisms remain unclear. Therefore, we established and characterized in vitro and in vivo models for ADPGK-deficiency using Jurkat T cells and zebrafish. Upon activation, ADPGK knockout Jurkat T cells displayed increased cell death and ER stress. The increase in cell death resulted from a metabolic catastrophe and knockout cells displayed severely disturbed energy metabolism hindering induction of Warburg phenotype. ADPGK knockdown in zebrafish embryos led to short, dorsalized body axis induced by elevated apoptosis. ADPGK hypomorphic zebrafish further displayed dysfunctional glucose metabolism. In both model systems loss of ADPGK function led to defective N- and O-glycosylation. Overall, our data illustrate that ADPGK is part of a glucose sensing system in the ER modulating metabolism via regulation of N- and O-glycosylation.
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Chapnick DA, Bunker E, Liu X, Old WM. Temporal Metabolite, Ion, and Enzyme Activity Profiling Using Fluorescence Microscopy and Genetically Encoded Biosensors. Methods Mol Biol 2019; 1978:343-353. [PMID: 31119673 DOI: 10.1007/978-1-4939-9236-2_21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Living cells employ complex and highly dynamic signaling networks and transcriptional circuits to maintain homeostasis and respond appropriately to constantly changing environments. These networks enable cells to maintain tight control on intracellular concentrations of ions, metabolites, proteins, and other biomolecules and ensure a careful balance between a cell's energetic needs and catabolic processes required for growth. Establishing molecular mechanisms of genetic and pharmacological perturbations remains challenging, due to the interconnected nature of these networks and the extreme sensitivity of cellular systems to their external environment. Live cell imaging with genetically encoded fluorescent biosensors provides a powerful new modality for nondestructive spatiotemporal tracking of ions, small molecules, enzymatic activities, and molecular interactions in living systems, from cells, tissues, and even living organisms. By deploying large panels of cell lines, each with distinct biosensors, many critical biochemical pathways can be monitored in a highly parallel and high-throughput fashion to identify pharmacological vulnerabilities and combination therapies unique to a given cell type or genetic background. Here we describe the experimental and analytical methods required to conduct multiplexed parallel fluorescence microscopy experiments on live cells expressing stable transgenic synthetic protein biosensors.
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Affiliation(s)
| | - Eric Bunker
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
| | - Xuedong Liu
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
| | - William M Old
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA.
- Linda Crnic Institute for Down Syndrome, University of Colorado School of Medicine, Aurora, CO, USA.
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16
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Müller MS, Fouyssac M, Taylor CW. Effective Glucose Uptake by Human Astrocytes Requires Its Sequestration in the Endoplasmic Reticulum by Glucose-6-Phosphatase-β. Curr Biol 2018; 28:3481-3486.e4. [PMID: 30415704 PMCID: PMC6224479 DOI: 10.1016/j.cub.2018.08.060] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/08/2018] [Accepted: 08/29/2018] [Indexed: 12/12/2022]
Abstract
After its uptake into the cytosol, intracellular glucose is phosphorylated to glucose-6-phosphate (G6P), trapping it within the cell and preparing it for metabolism. In glucose-exporting tissues, like liver, G6P is transported into the ER, where it is dephosphorylated by G6Pase-α. The glucose is then returned to the cytosol for export [1, 2]. Defects in these pathways cause glycogen storage diseases [1]. G6Pase-β, an isozyme of G6Pase-α, is widely expressed [3, 4]. Its role in cells that do not export glucose is unclear, although mutations in G6Pase-β cause severe and widespread abnormalities [5, 6, 7]. Astrocytes, the most abundant cells in the brain, provide metabolic support to neurons, facilitated by astrocytic endfeet that contact blood capillaries or neurons [8, 9, 10, 11, 12]. Perivascular endfeet are the main site of glucose uptake by astrocytes [13], but in human brain they may be several millimeters away from the perineuronal processes [14]. We show that cultured human fetal astrocytes express G6Pase-β, but not G6Pase-α. ER-targeted glucose sensors [15, 16] reveal that G6Pase-β allows the ER of human astrocytes to accumulate glucose by importing G6P from the cytosol. Glucose uptake by astrocytes, ATP production, and Ca2+ accumulation by the ER are attenuated after knockdown of G6Pase-β using lentivirus-delivered shRNA and substantially rescued by expression of G6Pase-α. We suggest that G6Pase-β activity allows effective uptake of glucose by astrocytes, and we speculate that it allows the ER to function as an intracellular “highway” delivering glucose from perivascular endfeet to the perisynaptic processes. Glucose-6-phosphatase-β (G6Pase-β) is expressed in human astrocytes G6P is sequestered by ER and dephosphorylated to glucose in the lumen by G6Pase-β Loss of G6Pase-β reduces glucose uptake, intracellular ATP, and ER Ca2+ content ER may provide a protected highway for long-range glucose transport in astrocytes
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Affiliation(s)
- Margit S Müller
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK.
| | - Maxime Fouyssac
- Department of Psychology, University of Cambridge, Cambridge CB2 3EB, UK
| | - Colin W Taylor
- Department of Pharmacology, University of Cambridge, Cambridge CB2 1PD, UK.
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Li Q, Zhou T, Wu F, Li N, Wang R, Zhao Q, Ma YM, Zhang JQ, Ma BL. Subcellular drug distribution: mechanisms and roles in drug efficacy, toxicity, resistance, and targeted delivery. Drug Metab Rev 2018; 50:430-447. [PMID: 30270675 DOI: 10.1080/03602532.2018.1512614] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
After administration, drug molecules usually enter target cells to access their intracellular targets. In eukaryotic cells, these targets are often located in organelles, including the nucleus, endoplasmic reticulum, mitochondria, lysosomes, Golgi apparatus, and peroxisomes. Each organelle type possesses unique biological features. For example, mitochondria possess a negative transmembrane potential, while lysosomes have an intraluminal delta pH. Other properties are common to several organelle types, such as the presence of ATP-binding cassette (ABC) or solute carrier-type (SLC) transporters that sequester or pump out xenobiotic drugs. Studies on subcellular drug distribution are critical to understand the efficacy and toxicity of drugs along with the body's resistance to them and to potentially offer hints for targeted subcellular drug delivery. This review summarizes the results of studies from 1990 to 2017 that examined the subcellular distribution of small molecular drugs. We hope this review will aid in the understanding of drug distribution within cells.
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Affiliation(s)
- Qiao Li
- a Department of Pharmacology , Shanghai University of Traditional Chinese Medicine , Shanghai , China
| | - Ting Zhou
- a Department of Pharmacology , Shanghai University of Traditional Chinese Medicine , Shanghai , China
| | - Fei Wu
- b Engineering Research Center of Modern Preparation Technology of TCM of Ministry of Education , Shanghai University of Traditional Chinese Medicine , Shanghai , China
| | - Na Li
- c Department of Chinese materia medica , School of Pharmacy , Shanghai , China
| | - Rui Wang
- b Engineering Research Center of Modern Preparation Technology of TCM of Ministry of Education , Shanghai University of Traditional Chinese Medicine , Shanghai , China
| | - Qing Zhao
- a Department of Pharmacology , Shanghai University of Traditional Chinese Medicine , Shanghai , China
| | - Yue-Ming Ma
- a Department of Pharmacology , Shanghai University of Traditional Chinese Medicine , Shanghai , China
| | - Ji-Quan Zhang
- b Engineering Research Center of Modern Preparation Technology of TCM of Ministry of Education , Shanghai University of Traditional Chinese Medicine , Shanghai , China
| | - Bing-Liang Ma
- a Department of Pharmacology , Shanghai University of Traditional Chinese Medicine , Shanghai , China
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18
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Gonzalez-Menendez P, Hevia D, Alonso-Arias R, Alvarez-Artime A, Rodriguez-Garcia A, Kinet S, Gonzalez-Pola I, Taylor N, Mayo JC, Sainz RM. GLUT1 protects prostate cancer cells from glucose deprivation-induced oxidative stress. Redox Biol 2018; 17:112-127. [PMID: 29684818 PMCID: PMC6007175 DOI: 10.1016/j.redox.2018.03.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 03/20/2018] [Accepted: 03/26/2018] [Indexed: 01/02/2023] Open
Abstract
Glucose, chief metabolic support for cancer cell survival and growth, is mainly imported into cells by facilitated glucose transporters (GLUTs). The increase in glucose uptake along with tumor progression is due to an increment of facilitative glucose transporters as GLUT1. GLUT1 prevents cell death of cancer cells caused by growth factors deprivation, but there is scarce information about its role on the damage caused by glucose deprivation, which usually occurs within the core of a growing tumor. In prostate cancer (PCa), GLUT1 is found in the most aggressive tumors, and it is regulated by androgens. To study the response of androgen-sensitive and insensitive PCa cells to glucose deprivation and the role of GLUT1 on survival mechanisms, androgen-sensitive LNCaP and castration-resistant LNCaP-R cells were employed. Results demonstrated that glucose deprivation induced a necrotic type of cell death which is prevented by antioxidants. Androgen-sensitive cells show a higher resistance to cell death triggered by glucose deprivation than castration-resistant cells. Glucose removal causes an increment of H2O2, an activation of androgen receptor (AR) and a stimulation of AMP-activated protein kinase activity. In addition, glucose removal increases GLUT1 production in androgen sensitive PCa cells. GLUT1 ectopic overexpression makes PCa cells more resistant to glucose deprivation and oxidative stress-induced cell death. Under glucose deprivation, GLUT1 overexpressing PCa cells sustains mitochondrial SOD2 activity, compromised after glucose removal, and significantly increases reduced glutathione (GSH). In conclusion, androgen-sensitive PCa cells are more resistant to glucose deprivation-induced cell death by a GLUT1 upregulation through an enhancement of reduced glutathione levels. Glucose deprivation carries an increase of free radicals in prostate cancer cells. The androgen receptor activation after glucose deprivation proceeds with GLUT1 overproduction. Treatment with hydrogen peroxide mimics the response to glucose deprivation. GLUT1-overexpressing prostate cancer cells are more resistant to glucose deprivation. Glutathione is more reduced in GLUT1-overexpressing cells under glucose deprivation.
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Affiliation(s)
- Pedro Gonzalez-Menendez
- Department of Morphology and Cell Biology, Redox Biology Unit. University Institute of Oncology of Asturias (IUOPA), University of Oviedo. Facultad de Medicina, Julián Clavería 6, 33006 Oviedo, Spain
| | - David Hevia
- Department of Morphology and Cell Biology, Redox Biology Unit. University Institute of Oncology of Asturias (IUOPA), University of Oviedo. Facultad de Medicina, Julián Clavería 6, 33006 Oviedo, Spain
| | - Rebeca Alonso-Arias
- Department of Immunology, Hospital Universitario Central de Asturias (HUCA), Avenida de Roma, 33011 Oviedo, Spain
| | - Alejandro Alvarez-Artime
- Department of Morphology and Cell Biology, Redox Biology Unit. University Institute of Oncology of Asturias (IUOPA), University of Oviedo. Facultad de Medicina, Julián Clavería 6, 33006 Oviedo, Spain
| | - Aida Rodriguez-Garcia
- Department of Microbiology, Tumor, and Cell Biology (MTC), Karolinska Institute, Tomtebodavägen 12C, Iastkajen, 171 65 Stockholm, Sweden
| | - Sandrina Kinet
- Institut de Genetique Moleculaire de Montpellier, Centre National de la Recherche Scientifique UMR5535, Universite de Montpellier 1 et 2, F-34293 Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Ivan Gonzalez-Pola
- Department of Morphology and Cell Biology, Redox Biology Unit. University Institute of Oncology of Asturias (IUOPA), University of Oviedo. Facultad de Medicina, Julián Clavería 6, 33006 Oviedo, Spain
| | - Naomi Taylor
- Institut de Genetique Moleculaire de Montpellier, Centre National de la Recherche Scientifique UMR5535, Universite de Montpellier 1 et 2, F-34293 Montpellier, France; Laboratory of Excellence GR-Ex, Paris 75015, France
| | - Juan C Mayo
- Department of Morphology and Cell Biology, Redox Biology Unit. University Institute of Oncology of Asturias (IUOPA), University of Oviedo. Facultad de Medicina, Julián Clavería 6, 33006 Oviedo, Spain.
| | - Rosa M Sainz
- Department of Morphology and Cell Biology, Redox Biology Unit. University Institute of Oncology of Asturias (IUOPA), University of Oviedo. Facultad de Medicina, Julián Clavería 6, 33006 Oviedo, Spain.
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Neelankal John A, Jiang FX. An overview of type 2 diabetes and importance of vitamin D3-vitamin D receptor interaction in pancreatic β-cells. J Diabetes Complications 2018; 32:429-443. [PMID: 29422234 DOI: 10.1016/j.jdiacomp.2017.12.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 12/03/2017] [Accepted: 12/07/2017] [Indexed: 02/07/2023]
Abstract
One significant health issue that plagues contemporary society is that of Type 2 diabetes (T2D). This disease is characterised by higher-than-average blood glucose levels as a result of a combination of insulin resistance and insufficient insulin secretions from the β-cells of pancreatic islets of Langerhans. Previous developmental research into the pancreas has identified how early precursor genes of pancreatic β-cells, such as Cpal, Ngn3, NeuroD, Ptf1a, and cMyc, play an essential role in the differentiation of these cells. Furthermore, β-cell molecular characterization has also revealed the specific role of β-cell-markers, such as Glut2, MafA, Ins1, Ins2, and Pdx1 in insulin expression. The expression of these genes appears to be suppressed in the T2D β-cells, along with the reappearance of the early endocrine marker genes. Glucose transporters transport glucose into β-cells, thereby controlling insulin release during hyperglycaemia. This stimulates glycolysis through rises in intracellular calcium (a process enhanced by vitamin D) (Norman et al., 1980), activating 2 of 4 proteinases. The rise in calcium activates half of pancreatic β-cell proinsulinases, thus releasing free insulin from granules. The synthesis of ATP from glucose by glycolysis, Krebs cycle and oxidative phosphorylation plays a role in insulin release. Some studies have found that the β-cells contain high levels of the vitamin D receptor; however, the role that this plays in maintaining the maturity of the β-cells remains unknown. Further research is required to develop a more in-depth understanding of the role VDR plays in β-cell function and the processes by which the beta cell function is preserved.
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Affiliation(s)
- Abraham Neelankal John
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia; School of Medicine and Pharmacology, University of Western Australia, Carwley, Western Australia, Australia
| | - Fang-Xu Jiang
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia; School of Medicine and Pharmacology, University of Western Australia, Carwley, Western Australia, Australia.
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Cytoplasmic p53 couples oncogene-driven glucose metabolism to apoptosis and is a therapeutic target in glioblastoma. Nat Med 2017; 23:1342-1351. [PMID: 29035366 PMCID: PMC5683421 DOI: 10.1038/nm.4418] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023]
Abstract
Cross-talk among oncogenic signaling and metabolic pathways may create
opportunities for novel therapeutic strategies in cancer. Here we show that
acute inhibition of EGFR-driven glucose metabolism induces minimal cell death,
yet lowers the apoptotic threshold in a subset of patient-derived glioblastoma
(GBM) cells. Mechanistic studies revealed that, following attenuated glucose
consumption, Bcl-xL blocks cytoplasmic p53 from triggering intrinsic apoptosis.
Consequently, pharmacological stabilization of p53 with the brain-penetrant
small molecule, Idasanutlin, in combination with targeting EGFR-driven glucose
metabolism promoted synthetic lethality in orthotopic xenograft models. Notably,
neither inhibition of EGFR signaling, nor genetic analysis of
EGFR, was sufficient to predict sensitivity to this new
therapeutic combination. Conversely, rapid changes in
18F-fluorodeoxyglucose (18F-FDG) uptake using non-invasive
positron emission tomography was an effective predictive biomarker of response
in vivo. Together, these studies identify a critical link between oncogene
signaling, glucose metabolism, and cytoplasmic p53, which could be exploited for
combination therapy in GBM and potentially, other malignancies.
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Leidenheimer NJ. Cognate Ligand Chaperoning: a Novel Mechanism for the Post-translational Regulation of Neurotransmitter Receptor Biogenesis. Front Cell Neurosci 2017; 11:245. [PMID: 28860972 PMCID: PMC5559506 DOI: 10.3389/fncel.2017.00245] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/02/2017] [Indexed: 11/13/2022] Open
Abstract
The functional unit for inter-neuronal communication in the central nervous system is the neuronal synapse. The number of postsynaptic neurotransmitter receptors at the cell surface is an important determinant of synaptic efficacy and plasticity. A diverse array of post-translational processes regulate postsynaptic receptor number, including receptor exocytosis, lateral diffusion, surface stabilization, endocytosis, and recycling, thus highlighting the importance of mechanisms that control postsynaptic receptor levels. Another putative post-translational mechanism for regulating receptor surface expression is cognate ligand chaperoning. It has been proposed that neurotransmitters function as cognate ligand chaperones by binding, within the endoplasmic reticulum (ER) lumen, to their nascent neurotransmitter receptors and facilitating receptor biogenesis. Here we discuss proof-of-concept evidence that small molecules can selectively facilitate the biogenesis of their targets and examine the specific evidence in support of cognate ligand chaperoning of neurotransmitter receptor biogenesis.
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Affiliation(s)
- Nancy J Leidenheimer
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences CenterShreveport, LA, United States
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22
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Seleit I, Bakry OA, Al-Sharaky DR, Ragab RAA, Al-Shiemy SA. Evaluation of Hypoxia Inducible Factor-1α and Glucose Transporter-1 Expression in Non Melanoma Skin Cancer: An Immunohistochemical Study. J Clin Diagn Res 2017; 11:EC09-EC16. [PMID: 28764171 DOI: 10.7860/jcdr/2017/25077.10022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/13/2017] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Hypoxia Inducible Factor-1 (HIF-1) is a mediator enabling cell adaptation to hypoxia. It plays its role mainly through transcription of many target genes including Glucose Transporter-1 (GLUT-1) gene. AIM The present work aimed at evaluating the pattern and distribution of HIF-1α and GLUT-1 in each case and control. MATERIALS AND METHODS A case-control and retrospective study was conducted on archival blocks diagnosed from pathology department as, Basal Cell Carcinoma (BCC, 20 cases), cutaneous Squamous Cell Carcinoma (SCC, 20 cases) and 20 normal site-matched skin biopsies from age and gender-matched healthy subjects as a control. Evaluation of both HIF-1α and GLUT1 expression using standard immunohistochemical techniques was performed on cut sections from selected paraffin embedded blocks. RESULTS HIF-1α was expressed in 90%, 35% and 100% of normal skin, BCC and SCC tumour islands respectively. It was up regulated in both BCC and SCC compared with normal skin (p= 0.001, p<0.001 respectively). GLUT-1 was expressed in 100%, 70% and 100% of normal skin, BCC and SCC tumour islands respectively. It was down regulated in Non Melanoma Skin Cancer (NMSC) cases compared with normal skin (p=0.004). HIF-1α and GLUT-1 localization in tumour nests was central, peripheral or central and peripheral. Both HIF-1α and GLUT-1 showed variable expression in stroma, adnexa and inflammatory cells. No significant correlation was found between Histo (H) score or expression percentage values of HIF-1α and those of GLUT-1 in tumour islands or in overlying epidermis either in BCC or SCC. CONCLUSION HIF-1α may have a role in NMSC pathogenesis through adaptation to hypoxia which results from excessive proliferation. GLUT-1 down regulation in NMSC may be explained by its consumption by proliferating tumour cells. The expression of HIF-1α and GLUT-1 in normal epidermis, stromal and adnexal structures needs further research.
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Affiliation(s)
- Iman Seleit
- Professor, Department of Dermatology, Andrology and S.T.Ds, Faculty of Medicine Menoufia University, Egypt
| | - Ola Ahmed Bakry
- Assistant Professor, Department of Dermatology, Andrology and S.T.Ds, Faculty of Medicine, Menoufia University, Egypt
| | - Dalia Rifaat Al-Sharaky
- Assistant Professor, Department of Pathology, Faculty of Medicine, Menoufia University, Egypt
| | - Rania Abdel Aziz Ragab
- Resident, Department of Dermatology, Andrology and S.T.Ds, Faculty of Medicine, Menoufia University, Egypt
| | - Shimaa Ahmed Al-Shiemy
- Resident, Department of Dermatology, Andrology and S.T.Ds, Faculty of Medicine, Menoufia University, Egypt
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Xie M, Ye H, Wang H, Charpin-El Hamri G, Lormeau C, Saxena P, Stelling J, Fussenegger M. -cell-mimetic designer cells provide closed-loop glycemic control. Science 2016; 354:1296-1301. [DOI: 10.1126/science.aaf4006] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 11/10/2016] [Indexed: 12/12/2022]
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Time-lapse 3-D measurements of a glucose biosensor in multicellular spheroids by light sheet fluorescence microscopy in commercial 96-well plates. Sci Rep 2016; 6:37777. [PMID: 27886235 PMCID: PMC5122899 DOI: 10.1038/srep37777] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 11/01/2016] [Indexed: 11/08/2022] Open
Abstract
Light sheet fluorescence microscopy has previously been demonstrated on a commercially available inverted fluorescence microscope frame using the method of oblique plane microscopy (OPM). In this paper, OPM is adapted to allow time-lapse 3-D imaging of 3-D biological cultures in commercially available glass-bottomed 96-well plates using a stage-scanning OPM approach (ssOPM). Time-lapse 3-D imaging of multicellular spheroids expressing a glucose Förster resonance energy transfer (FRET) biosensor is demonstrated in 16 fields of view with image acquisition at 10 minute intervals. As a proof-of-principle, the ssOPM system is also used to acquire a dose response curve with the concentration of glucose in the culture medium being varied across 42 wells of a 96-well plate with the whole acquisition taking 9 min. The 3-D image data enable the FRET ratio to be measured as a function of distance from the surface of the spheroid. Overall, the results demonstrate the capability of the OPM system to measure spatio-temporal changes in FRET ratio in 3-D in multicellular spheroids over time in a multi-well plate format.
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Liemburg-Apers DC, Schirris TJJ, Russel FGM, Willems PHGM, Koopman WJH. Mitoenergetic Dysfunction Triggers a Rapid Compensatory Increase in Steady-State Glucose Flux. Biophys J 2016; 109:1372-86. [PMID: 26445438 DOI: 10.1016/j.bpj.2015.08.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 07/13/2015] [Accepted: 08/03/2015] [Indexed: 10/23/2022] Open
Abstract
ATP can be produced in the cytosol by glycolytic conversion of glucose (GLC) into pyruvate. The latter can be metabolized into lactate, which is released by the cell, or taken up by mitochondria to fuel ATP production by the tricarboxylic acid cycle and oxidative phosphorylation (OXPHOS) system. Altering the balance between glycolytic and mitochondrial ATP generation is crucial for cell survival during mitoenergetic dysfunction, which is observed in a large variety of human disorders including cancer. To gain insight into the kinetic properties of this adaptive mechanism we determined here how acute (30 min) inhibition of OXPHOS affected cytosolic GLC homeostasis. GLC dynamics were analyzed in single living C2C12 myoblasts expressing the fluorescent biosensor FLII(12)Pglu-700μδ6 (FLII). Following in situ FLII calibration, the kinetic properties of GLC uptake (V1) and GLC consumption (V2) were determined independently and used to construct a minimal mathematical model of cytosolic GLC dynamics. After validating the model, it was applied to quantitatively predict V1 and V2 at steady-state (i.e., when V1 = V2 = Vsteady-state) in the absence and presence of OXPHOS inhibitors. Integrating model predictions with experimental data on lactate production, cell volume, and O2 consumption revealed that glycolysis and mitochondria equally contribute to cellular ATP production in control myoblasts. Inhibition of OXPHOS induced a twofold increase in Vsteady-state and glycolytic ATP production flux. Both in the absence and presence of OXPHOS inhibitors, GLC was consumed at near maximal rates, meaning that GLC consumption is rate-limiting under steady-state conditions. Taken together, we demonstrate here that OXPHOS inhibition increases steady-state GLC uptake and consumption in C2C12 myoblasts. This activation fully compensates for the reduction in mitochondrial ATP production, thereby maintaining the balance between cellular ATP supply and demand.
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Affiliation(s)
- Dania C Liemburg-Apers
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, Nijmegen, The Netherlands; Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Tom J J Schirris
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, Nijmegen, The Netherlands
| | - Frans G M Russel
- Department of Pharmacology and Toxicology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, Nijmegen, The Netherlands
| | - Peter H G M Willems
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, Nijmegen, The Netherlands; Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Werner J H Koopman
- Department of Biochemistry, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands; Centre for Systems Biology and Bioenergetics, Radboud University and Radboud University Medical Center, Nijmegen, The Netherlands; Nijmegen Center for Mitochondrial Disorders, Radboud University Medical Center, Nijmegen, The Netherlands.
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26
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Sánchez-Romero C, Bologna-Molina R, Mosqueda-Taylor A, Paes de Almeida O. Immunohistochemical Expression of GLUT-1 and HIF-1α in Tooth Germ, Ameloblastoma, and Ameloblastic Carcinoma. Int J Surg Pathol 2016; 24:410-8. [PMID: 27020375 DOI: 10.1177/1066896916640359] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Hypoxia-inducible factor-1α (HIF-1α) promotes proteins that enable cell survival during hypoxia, such as glucose transporter 1 (GLUT-1). Their coexpression has been associated with aggressiveness in malignancies and has not been studied in odontogenic tumors. Immunohistochemical expression of HIF-1α and GLUT-1 was analyzed in 13 tooth germs (TGs), 55 ameloblastomas (AMs), and 3 ameloblastic carcinomas (ACs). HIF-1α was negative in all TGs, and just 1 case of AM and 1 of AC had nuclear positivity. GLUT-1 expressed in ameloblastic cells of all TGs, AMs, and ACs, with an increasing intensity, respectively, and was significantly higher in solid AM than in unicystic AM (P = .041). Absence of nuclear HIF-1α in TGs and most AMs suggest that GLUT-1 may be induced by alternative pathways to hypoxia. However, in ACs, HIF-1α may be activated; however, to confirm this, additional cases are needed. GLUT-1 overexpression could be related to aggressiveness in AMs and ACs and must represent a normal metabolite in TGs.
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Németh CE, Marcolongo P, Gamberucci A, Fulceri R, Benedetti A, Zoppi N, Ritelli M, Chiarelli N, Colombi M, Willaert A, Callewaert BL, Coucke PJ, Gróf P, Nagy SK, Mészáros T, Bánhegyi G, Margittai É. Glucose transporter type 10-lacking in arterial tortuosity syndrome-facilitates dehydroascorbic acid transport. FEBS Lett 2016; 590:1630-40. [PMID: 27153185 DOI: 10.1002/1873-3468.12204] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/20/2016] [Accepted: 05/03/2016] [Indexed: 12/25/2022]
Abstract
Loss-of-function mutations in the gene encoding GLUT10 are responsible for arterial tortuosity syndrome (ATS), a rare connective tissue disorder. In this study GLUT10-mediated dehydroascorbic acid (DAA) transport was investigated, supposing its involvement in the pathomechanism. GLUT10 protein produced by in vitro translation and incorporated into liposomes efficiently transported DAA. Silencing of GLUT10 decreased DAA transport in immortalized human fibroblasts whose plasma membrane was selectively permeabilized. Similarly, the transport of DAA through endomembranes was markedly reduced in fibroblasts from ATS patients. Re-expression of GLUT10 in patients' fibroblasts restored DAA transport activity. The present results demonstrate that GLUT10 is a DAA transporter and DAA transport is diminished in the endomembranes of fibroblasts from ATS patients.
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Affiliation(s)
- Csilla E Németh
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Paola Marcolongo
- Department of Molecular and Developmental Medicine, University of Siena, Italy
| | | | - Rosella Fulceri
- Department of Molecular and Developmental Medicine, University of Siena, Italy
| | - Angiolo Benedetti
- Department of Molecular and Developmental Medicine, University of Siena, Italy
| | - Nicoletta Zoppi
- Division of Biology and Genetics, Department of Molecular and Translational Medicine, Medical Faculty, University of Brescia, Italy
| | - Marco Ritelli
- Division of Biology and Genetics, Department of Molecular and Translational Medicine, Medical Faculty, University of Brescia, Italy
| | - Nicola Chiarelli
- Division of Biology and Genetics, Department of Molecular and Translational Medicine, Medical Faculty, University of Brescia, Italy
| | - Marina Colombi
- Division of Biology and Genetics, Department of Molecular and Translational Medicine, Medical Faculty, University of Brescia, Italy
| | - Andy Willaert
- Center for Medical Genetics, Ghent University, Belgium
| | | | - Paul J Coucke
- Center for Medical Genetics, Ghent University, Belgium
| | - Pál Gróf
- Department of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Szilvia K Nagy
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Tamás Mészáros
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Gábor Bánhegyi
- Department of Medical Chemistry, Molecular Biology and Pathobiochemistry, Semmelweis University, Budapest, Hungary
| | - Éva Margittai
- Institute of Clinical Experimental Research, Semmelweis University, Budapest, Hungary
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28
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Brito AF, Abrantes AM, Ribeiro M, Oliveira R, Casalta-Lopes J, Gonçalves AC, Sarmento-Ribeiro AB, Tralhão JG, Botelho MF. Fluorine-18 Fluorodeoxyglucose Uptake in Hepatocellular Carcinoma: Correlation with Glucose Transporters and p53 Expression. J Clin Exp Hepatol 2015; 5:183-9. [PMID: 26628835 PMCID: PMC4632095 DOI: 10.1016/j.jceh.2015.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 05/25/2015] [Indexed: 02/07/2023] Open
Abstract
INTRODUCTION Hepatocellular Carcinoma (HCC) is one of most lethal cancers worldwide. The prognosis is very poor and therapeutic options are limited. The aim of this study was to determine the correlation of the [(18)F]FDG uptake profile of three HCC cell lines with p53 and glucose transporters (GLUTs) 1, 2, 3, 5 and 12 expression and with the glucose level present in the cell culture medium. METHODS Cell lines used are HepG2 (wp53), HuH7 (overexpress p53) and Hep3B2.1-7 (p53null). An immunocytochemical analysis was performed to evaluate p53 expression. Through uptake studies were analyzed the [(18)F]FDG uptake profiles of all cell lines under study. The expression of GLUTs were quantified by flow cytometry. The [(18)F]FDG uptake studies GLUTs expression analysis were performed on cells that grew in a high and low glucose medium in order to determine the effect of glucose concentration on GLUTs expression and on [(18)F]FDG uptake. RESULTS Immunocytochemical analysis confirmed the p53 expression profiles of all cell lines. It was found out that for all cell lines, [(18)F]FDG uptake is higher when cells grow in low glucose medium, however, the glucose level doesn't affect mostly the GLUTs expression. The Hep3B2.1-7 (p53null) is always the one that have higher [(18)F]FDG uptake. It was found that not always GLUT1 and GLUT3 are the most expressed by these cell lines. CONCLUSIONS Our results shown that the p53 expression influences [(18)F]FDG uptake. This suggests that [(18)F]FDG may be used in HCC diagnosis, and may even provide some information about the genetic profile of the tumor.
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Affiliation(s)
- Ana F. Brito
- Biophysics Unit, Faculty of Medicine of University of Coimbra, Coimbra, Portugal,Center of Investigation on Environmental, Genetics and Oncobiology (CIMAGO), Faculty of Medicine of University of Coimbra, Coimbra, Portugal,CNC.IBILI, University of Coimbra, Coimbra, Portugal,Address for correspondence: Ana F. Brito, Biophysics Unit, Faculty of Medicine of University of Coimbra, Pólo III – Pólo das Ciências da Saúde, Azinhaga de Santa Comba, Celas. 3000-548 Coimbra, Portugal. Tel.: +351 239480200; fax: +351 239480217.
| | - Ana M. Abrantes
- Biophysics Unit, Faculty of Medicine of University of Coimbra, Coimbra, Portugal,Center of Investigation on Environmental, Genetics and Oncobiology (CIMAGO), Faculty of Medicine of University of Coimbra, Coimbra, Portugal
| | - Marina Ribeiro
- Biophysics Unit, Faculty of Medicine of University of Coimbra, Coimbra, Portugal,Faculty of Sciences and Technology of University of Coimbra, Coimbra, Portugal
| | - Rui Oliveira
- Biophysics Unit, Faculty of Medicine of University of Coimbra, Coimbra, Portugal,Center of Investigation on Environmental, Genetics and Oncobiology (CIMAGO), Faculty of Medicine of University of Coimbra, Coimbra, Portugal,Anatomical Pathology Department, CHUC, Coimbra, Portugal
| | - João Casalta-Lopes
- Biophysics Unit, Faculty of Medicine of University of Coimbra, Coimbra, Portugal,Center of Investigation on Environmental, Genetics and Oncobiology (CIMAGO), Faculty of Medicine of University of Coimbra, Coimbra, Portugal
| | - Ana C. Gonçalves
- Center of Investigation on Environmental, Genetics and Oncobiology (CIMAGO), Faculty of Medicine of University of Coimbra, Coimbra, Portugal,CNC.IBILI, University of Coimbra, Coimbra, Portugal,Applied Molecular Biology and Hematology Group, Faculty of Medicine of University of Coimbra, Coimbra, Portugal
| | - Ana B. Sarmento-Ribeiro
- Center of Investigation on Environmental, Genetics and Oncobiology (CIMAGO), Faculty of Medicine of University of Coimbra, Coimbra, Portugal,CNC.IBILI, University of Coimbra, Coimbra, Portugal,Applied Molecular Biology and Hematology Group, Faculty of Medicine of University of Coimbra, Coimbra, Portugal
| | - José G. Tralhão
- Biophysics Unit, Faculty of Medicine of University of Coimbra, Coimbra, Portugal,Center of Investigation on Environmental, Genetics and Oncobiology (CIMAGO), Faculty of Medicine of University of Coimbra, Coimbra, Portugal,Surgical Department A, CHUC, Coimbra, Portugal
| | - Maria F. Botelho
- Biophysics Unit, Faculty of Medicine of University of Coimbra, Coimbra, Portugal,Center of Investigation on Environmental, Genetics and Oncobiology (CIMAGO), Faculty of Medicine of University of Coimbra, Coimbra, Portugal,CNC.IBILI, University of Coimbra, Coimbra, Portugal
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29
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Abdou AG, Eldien MMS, Elsakka D. GLUT-1 Expression in Cutaneous Basal and Squamous Cell Carcinomas. Int J Surg Pathol 2015; 23:447-53. [PMID: 26092229 DOI: 10.1177/1066896915589968] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Glucose uptake is a key regulating step in glucose metabolism and is mediated by facilitative glucose transporters (GLUTs), and GLUT-1 is the predominant glucose transporter in many types of human cells. Cutaneous basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) represent the most common skin cancer in Egypt. The present study aimed at evaluation of the pattern and distribution of GLUT-1 in cutaneous BCC (16 cases) and SCC (16 cases) by means of immunohistochemistry. GLUT-1 was expressed in all SCC (100%) and in 62.5% of BCC. Membranous pattern of GLUT-1 was seen in 62.5% of SCC and 31.25% of BCC. Positivity (P = .02) and percentage (P = .000) of GLUT-1 expression were in favor of SCC in comparison to BCC. The high percentage of GLUT-1 expression was associated with high grade in SCC (P = .03). The immunoreactivity for GLUT-1 was more in the periphery of malignant nests of SCC while it was more in the center of BCC nests. GLUT-1 is overexpressed in cutaneous non-melanoma skin cancer. Its expression in SCC is related to differentiation status, and its expression in BCC is intimately associated with squamous metaplastic areas.
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30
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Wang P, Eshaq RS, Meshul CK, Moore C, Hood RL, Leidenheimer NJ. Neuronal gamma-aminobutyric acid (GABA) type A receptors undergo cognate ligand chaperoning in the endoplasmic reticulum by endogenous GABA. Front Cell Neurosci 2015; 9:188. [PMID: 26041994 PMCID: PMC4435044 DOI: 10.3389/fncel.2015.00188] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/28/2015] [Indexed: 01/01/2023] Open
Abstract
GABAA receptors mediate fast inhibitory neurotransmission in the brain. Dysfunction of these receptors is associated with various psychiatric/neurological disorders and drugs targeting this receptor are widely used therapeutic agents. Both the efficacy and plasticity of GABAA receptor-mediated neurotransmission depends on the number of surface GABAA receptors. An understudied aspect of receptor cell surface expression is the post-translational regulation of receptor biogenesis within the endoplasmic reticulum (ER). We have previously shown that exogenous GABA can act as a ligand chaperone of recombinant GABAA receptors in the early secretory pathway leading us to now investigate whether endogenous GABA facilitates the biogenesis of GABAA receptors in primary cerebral cortical cultures. In immunofluorescence labeling experiments, we have determined that neurons expressing surface GABAA receptors contain both GABA and its degradative enzyme GABA transaminase (GABA-T). Treatment of neurons with GABA-T inhibitors, a treatment known to increase intracellular GABA levels, decreases the interaction of the receptor with the ER quality control protein calnexin, concomittantly increasing receptor forward-trafficking and plasma membrane insertion. The effect of GABA-T inhibition on the receptor/calnexin interaction is not due to the activation of surface GABAA or GABAB receptors. Consistent with our hypothesis that GABA acts as a cognate ligand chaperone in the ER, immunogold-labeling of rodent brain slices reveals the presence of GABA within the rough ER. The density of this labeling is similar to that present in mitochondria, the organelle in which GABA is degraded. Lastly, the effect of GABA-T inhibition on the receptor/calnexin interaction was prevented by pretreatment with a GABA transporter inhibitor. Together, these data indicate that endogenous GABA acts in the rough ER as a cognate ligand chaperone to facilitate the biogenesis of neuronal GABAA receptors.
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Affiliation(s)
- Ping Wang
- Department of Biochemistry and Molecular Biology, Louisiana State University, Health Sciences Center-Shreveport Shreveport, LA, USA
| | - Randa S Eshaq
- Department of Biochemistry and Molecular Biology, Louisiana State University, Health Sciences Center-Shreveport Shreveport, LA, USA
| | - Charles K Meshul
- Veterans Hospital Portland/Research Services/Neurocytology Laboratory and Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Cynthia Moore
- Veterans Hospital Portland/Research Services/Neurocytology Laboratory and Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Rebecca L Hood
- Veterans Hospital Portland/Research Services/Neurocytology Laboratory and Department of Behavioral Neuroscience, Oregon Health & Science University Portland, OR, USA
| | - Nancy J Leidenheimer
- Department of Biochemistry and Molecular Biology, Louisiana State University, Health Sciences Center-Shreveport Shreveport, LA, USA
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31
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Mi YJ, Geng GJ, Zou ZZ, Gao J, Luo XY, Liu Y, Li N, Li CL, Chen YQ, Yu XY, Jiang J. Dihydroartemisinin inhibits glucose uptake and cooperates with glycolysis inhibitor to induce apoptosis in non-small cell lung carcinoma cells. PLoS One 2015; 10:e0120426. [PMID: 25799586 PMCID: PMC4370589 DOI: 10.1371/journal.pone.0120426] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/22/2015] [Indexed: 01/16/2023] Open
Abstract
Despite recent advances in the therapy of non-small cell lung cancer (NSCLC), the chemotherapy efficacy against NSCLC is still unsatisfactory. Previous studies show the herbal antimalarial drug dihydroartemisinin (DHA) displays cytotoxic to multiple human tumors. Here, we showed that DHA decreased cell viability and colony formation, induced apoptosis in A549 and PC-9 cells. Additionally, we first revealed DHA inhibited glucose uptake in NSCLC cells. Moreover, glycolytic metabolism was attenuated by DHA, including inhibition of ATP and lactate production. Consequently, we demonstrated that the phosphorylated forms of both S6 ribosomal protein and mechanistic target of rapamycin (mTOR), and GLUT1 levels were abrogated by DHA treatment in NSCLC cells. Furthermore, the upregulation of mTOR activation by high expressed Rheb increased the level of glycolytic metabolism and cell viability inhibited by DHA. These results suggested that DHA-suppressed glycolytic metabolism might be associated with mTOR activation and GLUT1 expression. Besides, we showed GLUT1 overexpression significantly attenuated DHA-triggered NSCLC cells apoptosis. Notably, DHA synergized with 2-Deoxy-D-glucose (2DG, a glycolysis inhibitor) to reduce cell viability and increase cell apoptosis in A549 and PC-9 cells. However, the combination of the two compounds displayed minimal toxicity to WI-38 cells, a normal lung fibroblast cell line. More importantly, 2DG synergistically potentiated DHA-induced activation of caspase-9, -8 and -3, as well as the levels of both cytochrome c and AIF of cytoplasm. However, 2DG failed to increase the reactive oxygen species (ROS) levels elicited by DHA. Overall, the data shown above indicated DHA plus 2DG induced apoptosis was involved in both extrinsic and intrinsic apoptosis pathways in NSCLC cells.
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Affiliation(s)
- Yan-jun Mi
- Department of thoracic surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China
- Department of Medical Oncology, Chenggong Hospital of Xiamen University, Xiamen, China
| | - Guo-jun Geng
- Department of thoracic surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Zheng-zhi Zou
- MOE Key Laboratory of Laser Life Science and Institute of Laser Life Science, College of Biophotonics, South China Normal University, Guangzhou, China
| | - Jing Gao
- Department of Head and Neck Surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Xian-yang Luo
- Department of Head and Neck Surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Yu Liu
- Department of thoracic surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Ning Li
- Department of thoracic surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Chun-lei Li
- Department of thoracic surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Yu-qiang Chen
- Department of Medical Oncology, Chenggong Hospital of Xiamen University, Xiamen, China
| | - Xiu-yi Yu
- Department of thoracic surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China
- * E-mail: (XYY); (JJ)
| | - Jie Jiang
- Department of thoracic surgery, The First Affiliated Hospital of Xiamen University, Xiamen, China
- * E-mail: (XYY); (JJ)
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Abstract
Soluble sugars serve five main purposes in multicellular organisms: as sources of carbon skeletons, osmolytes, signals, and transient energy storage and as transport molecules. Most sugars are derived from photosynthetic organisms, particularly plants. In multicellular organisms, some cells specialize in providing sugars to other cells (e.g., intestinal and liver cells in animals, photosynthetic cells in plants), whereas others depend completely on an external supply (e.g., brain cells, roots and seeds). This cellular exchange of sugars requires transport proteins to mediate uptake or release from cells or subcellular compartments. Thus, not surprisingly, sugar transport is critical for plants, animals, and humans. At present, three classes of eukaryotic sugar transporters have been characterized, namely the glucose transporters (GLUTs), sodium-glucose symporters (SGLTs), and SWEETs. This review presents the history and state of the art of sugar transporter research, covering genetics, biochemistry, and physiology-from their identification and characterization to their structure, function, and physiology. In humans, understanding sugar transport has therapeutic importance (e.g., addressing diabetes or limiting access of cancer cells to sugars), and in plants, these transporters are critical for crop yield and pathogen susceptibility.
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Affiliation(s)
- Li-Qing Chen
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305;
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33
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Fong MY, Zhou W, Liu L, Alontaga AY, Chandra M, Ashby J, Chow A, O'Connor STF, Li S, Chin AR, Somlo G, Palomares M, Li Z, Tremblay JR, Tsuyada A, Sun G, Reid MA, Wu X, Swiderski P, Ren X, Shi Y, Kong M, Zhong W, Chen Y, Wang SE. Breast-cancer-secreted miR-122 reprograms glucose metabolism in premetastatic niche to promote metastasis. Nat Cell Biol 2015; 17:183-94. [PMID: 25621950 PMCID: PMC4380143 DOI: 10.1038/ncb3094] [Citation(s) in RCA: 848] [Impact Index Per Article: 94.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 12/11/2014] [Indexed: 02/07/2023]
Abstract
Reprogrammed glucose metabolism as a result of increased glycolysis and glucose uptake is a hallmark of cancer. Here we show that cancer cells can suppress glucose uptake by non-tumour cells in the pre-metastatic niche, by secreting vesicles that carry high levels of the miR-122 microRNA. High miR-122 levels in the circulation have been associated with metastasis in breast cancer patients and we show that cancer-cell-secreted miR-122 facilitates metastasis by increasing nutrient availability in the pre-metastatic niche. Mechanistically cancer-cell-derived miR-122 suppresses glucose uptake by niche cells in vitro and in vivo by downregulating the glycolytic enzyme pyruvate kinase (PKM). In vivo inhibition of miR-122 restores glucose uptake in distant organs, including brain and lungs, and decreases the incidence of metastasis. These results demonstrate that by modifying glucose utilization by recipient pre-metastatic niche cells, cancer-derived extracellular miR-122 is able to reprogram systemic energy metabolism to facilitate disease progression.
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Affiliation(s)
- Miranda Y Fong
- Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Weiying Zhou
- Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Liang Liu
- 1] Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA [2] Department of Biotherapy and Key Laboratory of Cancer Immunology, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China
| | - Aileen Y Alontaga
- Department of Molecular Medicine, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Manasa Chandra
- 1] Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA [2] City of Hope Irell &Manella Graduate School of Biological Sciences, Duarte, California 91010, USA
| | - Jonathan Ashby
- Department of Chemistry, University of California, Riverside, California 92521, USA
| | - Amy Chow
- Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | | | - Shasha Li
- Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Andrew R Chin
- 1] Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA [2] City of Hope Irell &Manella Graduate School of Biological Sciences, Duarte, California 91010, USA
| | - George Somlo
- Department of Medical Oncology, City of Hope Medical Center, Duarte, California 91010, USA
| | - Melanie Palomares
- 1] Department of Medical Oncology, City of Hope Medical Center, Duarte, California 91010, USA [2] Department of Population Sciences, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Zhuo Li
- Core of Electron Microscopy, City of Hope Comprehensive Cancer Center, Duarte, California 91010, USA
| | - Jacob R Tremblay
- 1] Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA [2] City of Hope Irell &Manella Graduate School of Biological Sciences, Duarte, California 91010, USA
| | - Akihiro Tsuyada
- Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Guoqiang Sun
- Department of Neurosciences, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Michael A Reid
- Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Xiwei Wu
- Core of Integrative Genomics, City of Hope Comprehensive Cancer Center, Duarte, California 91010, USA
| | - Piotr Swiderski
- Core of Synthetic and Biopolymer Chemistry, City of Hope Comprehensive Cancer Center, Duarte, California 91010, USA
| | - Xiubao Ren
- Department of Biotherapy and Key Laboratory of Cancer Immunology, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China
| | - Yanhong Shi
- Department of Neurosciences, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Mei Kong
- Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Wenwan Zhong
- Department of Chemistry, University of California, Riverside, California 92521, USA
| | - Yuan Chen
- Department of Molecular Medicine, City of Hope Beckman Research Institute, Duarte, California 91010, USA
| | - Shizhen Emily Wang
- 1] Department of Cancer Biology, City of Hope Beckman Research Institute, Duarte, California 91010, USA [2] Department of Biotherapy and Key Laboratory of Cancer Immunology, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060, China
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Pardee K, Green AA, Ferrante T, Cameron DE, DaleyKeyser A, Yin P, Collins JJ. Paper-based synthetic gene networks. Cell 2014; 159:940-54. [PMID: 25417167 PMCID: PMC4243060 DOI: 10.1016/j.cell.2014.10.004] [Citation(s) in RCA: 446] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 09/29/2014] [Accepted: 10/03/2014] [Indexed: 01/21/2023]
Abstract
Synthetic gene networks have wide-ranging uses in reprogramming and rewiring organisms. To date, there has not been a way to harness the vast potential of these networks beyond the constraints of a laboratory or in vivo environment. Here, we present an in vitro paper-based platform that provides an alternate, versatile venue for synthetic biologists to operate and a much-needed medium for the safe deployment of engineered gene circuits beyond the lab. Commercially available cell-free systems are freeze dried onto paper, enabling the inexpensive, sterile, and abiotic distribution of synthetic-biology-based technologies for the clinic, global health, industry, research, and education. For field use, we create circuits with colorimetric outputs for detection by eye and fabricate a low-cost, electronic optical interface. We demonstrate this technology with small-molecule and RNA actuation of genetic switches, rapid prototyping of complex gene circuits, and programmable in vitro diagnostics, including glucose sensors and strain-specific Ebola virus sensors.
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Affiliation(s)
- Keith Pardee
- Wyss Institute for Biological Inspired Engineering, Harvard University, Boston, MA 02115, USA; Department of Biomedical Engineering and Center of Synthetic Biology, Boston University, Boston, MA 02215, USA
| | - Alexander A Green
- Wyss Institute for Biological Inspired Engineering, Harvard University, Boston, MA 02115, USA; Department of Biomedical Engineering and Center of Synthetic Biology, Boston University, Boston, MA 02215, USA
| | - Tom Ferrante
- Wyss Institute for Biological Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - D Ewen Cameron
- Department of Biomedical Engineering and Center of Synthetic Biology, Boston University, Boston, MA 02215, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Ajay DaleyKeyser
- Wyss Institute for Biological Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - Peng Yin
- Wyss Institute for Biological Inspired Engineering, Harvard University, Boston, MA 02115, USA
| | - James J Collins
- Wyss Institute for Biological Inspired Engineering, Harvard University, Boston, MA 02115, USA; Department of Biomedical Engineering and Center of Synthetic Biology, Boston University, Boston, MA 02215, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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San Martín A, Sotelo-Hitschfeld T, Lerchundi R, Fernández-Moncada I, Ceballo S, Valdebenito R, Baeza-Lehnert F, Alegría K, Contreras-Baeza Y, Garrido-Gerter P, Romero-Gómez I, Barros LF. Single-cell imaging tools for brain energy metabolism: a review. NEUROPHOTONICS 2014; 1:011004. [PMID: 26157964 PMCID: PMC4478754 DOI: 10.1117/1.nph.1.1.011004] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 04/09/2014] [Accepted: 04/10/2014] [Indexed: 05/03/2023]
Abstract
Neurophotonics comes to light at a time in which advances in microscopy and improved calcium reporters are paving the way toward high-resolution functional mapping of the brain. This review relates to a parallel revolution in metabolism. We argue that metabolism needs to be approached both in vitro and in vivo, and that it does not just exist as a low-level platform but is also a relevant player in information processing. In recent years, genetically encoded fluorescent nanosensors have been introduced to measure glucose, glutamate, ATP, NADH, lactate, and pyruvate in mammalian cells. Reporting relative metabolite levels, absolute concentrations, and metabolic fluxes, these sensors are instrumental for the discovery of new molecular mechanisms. Sensors continue to be developed, which together with a continued improvement in protein expression strategies and new imaging technologies, herald an exciting era of high-resolution characterization of metabolism in the brain and other organs.
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Affiliation(s)
- Alejandro San Martín
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Tamara Sotelo-Hitschfeld
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Rodrigo Lerchundi
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Ignacio Fernández-Moncada
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Sebastian Ceballo
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
| | - Rocío Valdebenito
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
| | | | - Karin Alegría
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
| | - Yasna Contreras-Baeza
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Pamela Garrido-Gerter
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - Ignacio Romero-Gómez
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Universidad Austral de Chile, Valdivia, Chile
| | - L. Felipe Barros
- Centro de Estudios Científicos, Arturo Prat 514, Valdivia, 5110466, Chile
- Address all correspondence to: L. Felipe Barros, E-mail:
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Cura AJ, Carruthers A. Role of monosaccharide transport proteins in carbohydrate assimilation, distribution, metabolism, and homeostasis. Compr Physiol 2013; 2:863-914. [PMID: 22943001 DOI: 10.1002/cphy.c110024] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The facilitated diffusion of glucose, galactose, fructose, urate, myoinositol, and dehydroascorbicacid in mammals is catalyzed by a family of 14 monosaccharide transport proteins called GLUTs. These transporters may be divided into three classes according to sequence similarity and function/substrate specificity. GLUT1 appears to be highly expressed in glycolytically active cells and has been coopted in vitamin C auxotrophs to maintain the redox state of the blood through transport of dehydroascorbate. Several GLUTs are definitive glucose/galactose transporters, GLUT2 and GLUT5 are physiologically important fructose transporters, GLUT9 appears to be a urate transporter while GLUT13 is a proton/myoinositol cotransporter. The physiologic substrates of some GLUTs remain to be established. The GLUTs are expressed in a tissue specific manner where affinity, specificity, and capacity for substrate transport are paramount for tissue function. Although great strides have been made in characterizing GLUT-catalyzed monosaccharide transport and mapping GLUT membrane topography and determinants of substrate specificity, a unifying model for GLUT structure and function remains elusive. The GLUTs play a major role in carbohydrate homeostasis and the redistribution of sugar-derived carbons among the various organ systems. This is accomplished through a multiplicity of GLUT-dependent glucose sensing and effector mechanisms that regulate monosaccharide ingestion, absorption,distribution, cellular transport and metabolism, and recovery/retention. Glucose transport and metabolism have coevolved in mammals to support cerebral glucose utilization.
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Affiliation(s)
- Anthony J Cura
- Department of Biochemistry & Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
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Yee DC, Shlykov MA, Västermark A, Reddy VS, Arora S, Sun EI, Saier MH. The transporter-opsin-G protein-coupled receptor (TOG) superfamily. FEBS J 2013; 280:5780-800. [PMID: 23981446 DOI: 10.1111/febs.12499] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Revised: 08/06/2013] [Accepted: 08/06/2013] [Indexed: 01/27/2023]
Abstract
Visual rhodopsins are recognized members of the large and diverse family of G protein-coupled receptors (GPCRs), but their evolutionary origin and relationships to other proteins are not known. In a previous paper [Shlykov MA, Zheng WH, Chen JS & Saier MH Jr (2012) Biochim Biophys Acta 1818, 703-717], we characterized the 4-toluene sulfonate uptake permease (TSUP) family of transmembrane proteins, and showed that these 7-transmembrane segment (TMS) or 8-TMS proteins arose by intragenic duplication of a gene encoding a 4-TMS protein, sometimes followed by loss of a terminal TMS. In this study, we show that the TSUP, GPCR and microbial rhodopsin families are related to each other and to six other currently recognized transport protein families. We designate this superfamily the transporter/opsin/G protein-coupled receptor (TOG) superfamily. Despite their 8-TMS origins, the members of most constituent families exhibit 7-TMS topologies that are well conserved, and these arose by loss of either the N-terminal TMS (more frequent) or the C-terminal TMS (less frequent), depending on the family. Phylogenetic analyses revealed familial relationships within the superfamily and protein relationships within each of the nine families. The results of the statistical analyses leading to the conclusion of homology were confirmed using hidden Markov models, Pfam and 3D superimpositions. Proteins functioning by dissimilar mechanisms (channels, primary active transporters, secondary active transporters, group translocators and receptors) are interspersed on a phylogenetic tree of the TOG superfamily, suggesting that changes in the transport and energy-coupling mechanisms occurred multiple times during evolution of this superfamily.
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Affiliation(s)
- Daniel C Yee
- Division of Biological Sciences, University of California at San Diego, La Jolla, CA, USA
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Jones AM, Grossmann G, Danielson JÅ, Sosso D, Chen LQ, Ho CH, Frommer WB. In vivo biochemistry: applications for small molecule biosensors in plant biology. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:389-95. [PMID: 23587939 PMCID: PMC3679211 DOI: 10.1016/j.pbi.2013.02.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 02/22/2013] [Accepted: 02/22/2013] [Indexed: 05/02/2023]
Abstract
Revolutionary new technologies, namely in the areas of DNA sequencing and molecular imaging, continue to impact new discoveries in plant science and beyond. For decades we have been able to determine properties of enzymes, receptors and transporters in vitro or in heterologous systems, and more recently been able to analyze their regulation at the transcriptional level, to use GFP reporters for obtaining insights into cellular and subcellular localization, and tp measure ion and metabolite levels with unprecedented precision using mass spectrometry. However, we lack key information on the location and dynamics of the substrates of enzymes, receptors and transporters, and on the regulation of these proteins in their cellular environment. Such information can now be obtained by transitioning from in vitro to in vivo biochemistry using biosensors. Genetically encoded fluorescent protein-based sensors for ion and metabolite dynamics provide highly resolved spatial and temporal information, and are complemented by sensors for pH, redox, voltage, and tension. They serve as powerful tools for identifying missing processes (e.g., glucose transport across ER membranes), components (e.g., SWEET sugar transporters for cellular sugar efflux), and signaling networks (e.g., from systematic screening of mutants that affect sugar transport or cytosolic and vacuolar pH). Combined with the knowledge of properties of enzymes and transporters and their interactions with the regulatory machinery, biosensors promise to be key diagnostic tools for systems and synthetic biology.
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Affiliation(s)
- Alexander M Jones
- Carnegie Institution for Science, Department of Plant Biology, 260 Panama St., Stanford, CA 94305, USA
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Reevaluating Metabolism in Alzheimer's Disease from the Perspective of the Astrocyte-Neuron Lactate Shuttle Model. JOURNAL OF NEURODEGENERATIVE DISEASES 2013; 2013:234572. [PMID: 26316984 PMCID: PMC4437330 DOI: 10.1155/2013/234572] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Accepted: 04/02/2013] [Indexed: 01/19/2023]
Abstract
The conventional view of central nervous system (CNS) metabolism is based on the assumption that glucose is the main fuel source for active neurons and is processed in an oxidative manner. However, since the early 1990s research has challenged the idea that the energy needs of nerve cells are met exclusively by glucose and oxidative metabolism. This alternative view of glucose utilization contends that astrocytes metabolize glucose to lactate, which is then released and taken up by nearby neurons and used as a fuel source, commonly known as the astrocyte-neuron lactate shuttle (ANLS) model. Once thought of as a waste metabolite, lactate has emerged as a central player in the maintenance of neuronal function and long-term memory. Decreased neuronal metabolism has traditionally been viewed as a hallmark feature of Alzheimer's disease (AD). However, a more complex picture of CNS metabolism is emerging that may provide valuable insight into the pathophysiological changes that occur during AD and other neurodegenerative diseases. This review will examine the ANLS model and present recent evidence highlighting the critical role that lactate plays in neuronal survival and memory. Moreover, the role of glucose and lactate metabolism in AD will be re-evaluated from the perspective of the ANLS.
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Barros LF, San Martín A, Sotelo-Hitschfeld T, Lerchundi R, Fernández-Moncada I, Ruminot I, Gutiérrez R, Valdebenito R, Ceballo S, Alegría K, Baeza-Lehnert F, Espinoza D. Small is fast: astrocytic glucose and lactate metabolism at cellular resolution. Front Cell Neurosci 2013; 7:27. [PMID: 23526722 PMCID: PMC3605549 DOI: 10.3389/fncel.2013.00027] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 03/03/2013] [Indexed: 12/28/2022] Open
Abstract
Brain tissue is highly dynamic in terms of electrical activity and energy demand. Relevant energy metabolites have turnover times ranging from milliseconds to seconds and are rapidly exchanged between cells and within cells. Until recently these fast metabolic events were inaccessible, because standard isotopic techniques require use of populations of cells and/or involve integration times of tens of minutes. Thanks to fluorescent probes and recently available genetically-encoded optical nanosensors, this Technology Report shows how it is now possible to monitor the concentration of metabolites in real-time and in single cells. In combination with ad hoc inhibitor-stop protocols, these probes have revealed a key role for K+ in the acute stimulation of astrocytic glycolysis by synaptic activity. They have also permitted detection of the Warburg effect in single cancer cells. Genetically-encoded nanosensors currently exist for glucose, lactate, NADH and ATP, and it is envisaged that other metabolite nanosensors will soon be available. These optical tools together with improved expression systems and in vivo imaging, herald an exciting era of single-cell metabolic analysis.
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Affiliation(s)
- L F Barros
- Centro de Estudios Científicos Valdivia, Chile
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41
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Multiple roles of glucose-6-phosphatases in pathophysiology. Biochim Biophys Acta Gen Subj 2013; 1830:2608-18. [DOI: 10.1016/j.bbagen.2012.12.013] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 12/11/2012] [Accepted: 12/13/2012] [Indexed: 12/28/2022]
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San Martín A, Ceballo S, Ruminot I, Lerchundi R, Frommer WB, Barros LF. A genetically encoded FRET lactate sensor and its use to detect the Warburg effect in single cancer cells. PLoS One 2013; 8:e57712. [PMID: 23469056 PMCID: PMC3582500 DOI: 10.1371/journal.pone.0057712] [Citation(s) in RCA: 244] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 01/24/2013] [Indexed: 11/18/2022] Open
Abstract
Lactate is shuttled between and inside cells, playing metabolic and signaling roles in healthy tissues. Lactate is also a harbinger of altered metabolism and participates in the pathogenesis of inflammation, hypoxia/ischemia, neurodegeneration and cancer. Many tumor cells show high rates of lactate production in the presence of oxygen, a phenomenon known as the Warburg effect, which has diagnostic and possibly therapeutic implications. In this article we introduce Laconic, a genetically-encoded Forster Resonance Energy Transfer (FRET)-based lactate sensor designed on the bacterial transcription factor LldR. Laconic quantified lactate from 1 µM to 10 mM and was not affected by glucose, pyruvate, acetate, betahydroxybutyrate, glutamate, citrate, α-ketoglutarate, succinate, malate or oxalacetate at concentrations found in mammalian cytosol. Expressed in astrocytes, HEK cells and T98G glioma cells, the sensor allowed dynamic estimation of lactate levels in single cells. Used in combination with a blocker of the monocarboxylate transporter MCT, the sensor was capable of discriminating whether a cell is a net lactate producer or a net lactate consumer. Application of the MCT-block protocol showed that the basal rate of lactate production is 3–5 fold higher in T98G glioma cells than in normal astrocytes. In contrast, the rate of lactate accumulation in response to mitochondrial inhibition with sodium azide was 10 times lower in glioma than in astrocytes, consistent with defective tumor metabolism. A ratio between the rate of lactate production and the rate of azide-induced lactate accumulation, which can be estimated reversibly and in single cells, was identified as a highly sensitive parameter of the Warburg effect, with values of 4.1 ± 0.5 for T98G glioma cells and 0.07 ± 0.007 for astrocytes. In summary, this article describes a genetically-encoded sensor for lactate and its use to measure lactate concentration, lactate flux, and the Warburg effect in single mammalian cells.
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43
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Kaminski MT, Lenzen S, Baltrusch S. Real-time analysis of intracellular glucose and calcium in pancreatic beta cells by fluorescence microscopy. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1697-707. [PMID: 22732296 DOI: 10.1016/j.bbamcr.2012.06.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 06/13/2012] [Accepted: 06/15/2012] [Indexed: 12/29/2022]
Abstract
Glucose is the physiological stimulus for insulin secretion in pancreatic beta cells. The uptake and phosphorylation of glucose initiate and control downstream pathways, resulting in insulin secretion. However, the temporal coordination of these events in beta cells is not fully understood. The recent development of the FLII(12)Pglu-700μ-δ6 glucose nanosensor facilitates real-time analysis of intracellular glucose within a broad concentration range. Using this fluorescence-based technique, we show the shift in intracellular glucose concentration upon external supply and removal in primary mouse beta cells with high resolution. Glucose influx, efflux, and metabolism rates were calculated from the time-dependent plots. Comparison of insulin-producing cells with different expression levels of glucose transporters and phosphorylating enzymes showed that a high glucose influx rate correlated with GLUT2 expression, but was largely also sustainable by high GLUT1 expression. In contrast, in cells not expressing the glucose sensor enzyme glucokinase glucose metabolism was slow. We found no evidence of oscillations of the intracellular glucose concentration in beta cells. Concomitant real-time analysis of glucose and calcium dynamics using FLII(12)Pglu-700μ-δ6 and fura-2-acetoxymethyl-ester determined a glucose threshold of 4mM for the [Ca(2+)](i) increase in beta cells. Indeed, a glucose concentration of 7mM had to be reached to evoke large amplitude [Ca(2+)](i) oscillations. The K(ATP) channel closing agent glibenclamide was not able to induce large amplitude [Ca(2+)](i) oscillations in the absence of glucose. Our findings suggest that glucose has to reach a threshold to evoke the [Ca(2+)](i) increase and subsequently initiate [Ca(2+)](i) oscillations in a K(ATP) channel independent manner.
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Chen LQ, Qu XQ, Hou BH, Sosso D, Osorio S, Fernie AR, Frommer WB. Sucrose efflux mediated by SWEET proteins as a key step for phloem transport. Science 2011; 335:207-11. [PMID: 22157085 DOI: 10.1126/science.1213351] [Citation(s) in RCA: 786] [Impact Index Per Article: 60.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Plants transport fixed carbon predominantly as sucrose, which is produced in mesophyll cells and imported into phloem cells for translocation throughout the plant. It is not known how sucrose migrates from sites of synthesis in the mesophyll to the phloem, or which cells mediate efflux into the apoplasm as a prerequisite for phloem loading by the SUT sucrose-H(+) (proton) cotransporters. Using optical sucrose sensors, we identified a subfamily of SWEET sucrose efflux transporters. AtSWEET11 and 12 localize to the plasma membrane of the phloem. Mutant plants carrying insertions in AtSWEET11 and 12 are defective in phloem loading, thus revealing a two-step mechanism of SWEET-mediated export from parenchyma cells feeding H(+)-coupled import into the sieve element-companion cell complex. We discuss how restriction of intercellular transport to the interface of adjacent phloem cells may be an effective mechanism to limit the availability of photosynthetic carbon in the leaf apoplasm in order to prevent pathogen infections.
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Affiliation(s)
- Li-Qing Chen
- Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305, USA
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45
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Optical sensors for monitoring dynamic changes of intracellular metabolite levels in mammalian cells. Nat Protoc 2011; 6:1818-33. [PMID: 22036884 DOI: 10.1038/nprot.2011.392] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Knowledge of the in vivo levels, distribution and flux of ions and metabolites is crucial to our understanding of physiology in both healthy and diseased states. The quantitative analysis of the dynamics of ions and metabolites with subcellular resolution in vivo poses a major challenge for the analysis of metabolic processes. Genetically encoded Förster resonance energy transfer (FRET) sensors can be used for real-time in vivo detection of metabolites. FRET sensor proteins, for example, for glucose, can be targeted genetically to any cellular compartment, or even to subdomains (e.g., a membrane surface), by adding signal sequences or fusing the sensors to specific proteins. The sensors can be used for analyses in individual mammalian cells in culture, in tissue slices and in intact organisms. Applications include gene discovery, high-throughput drug screens or systematic analysis of regulatory networks affecting uptake, efflux and metabolism. Quantitative analyses obtained with the help of FRET sensors for glucose or other ions and metabolites provide valuable data for modeling of flux. Here we provide a detailed protocol for monitoring glucose levels in the cytosol of mammalian cell cultures through the use of FRET glucose sensors; moreover, the protocol can be used for other ions and metabolites and for analyses in other organisms, as has been successfully demonstrated in bacteria, yeast and even intact plants. The whole procedure typically takes ∼4 d including seeding and transfection of mammalian cells; the FRET-based analysis of transfected cells takes ∼5 h.
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Abstract
Optical sensors allow dynamic quantification of metabolite levels with subcellular resolution. Here we describe protocols for analyzing cytosolic glucose levels in yeast using genetically encoded Förster resonance energy transfer (FRET) sensors. FRET glucose sensors with different glucose affinities (K(d)) covering the low nano- to mid- millimolar range can be targeted genetically to the cytosol or to subcellular compartments. The sensors detect the glucose-induced conformational change in the bacterial periplasmic glucose/galactose binding protein MglB using FRET between two fluorescent protein variants. Measurements can be performed with a single sensor or multiple sensors in parallel. In one approach, cytosolic glucose accumulation is measured in yeast cultures in a 96-well plate using a fluorimeter. Upon excitation of the cyan fluorescent protein (CFP), emission intensities of CFP and YFP (yellow fluorescent protein) are captured before and after glucose addition. FRET sensors provide temporally resolved quantitative data of glucose for the compartment of interest. In a second approach, reversible changes of cytosolic free glucose are measured in individual yeast cells trapped in a microfluidic platform, allowing perfusion of different solutions while FRET changes are monitored in a microscope setup. By using the microplate fluorimeter protocol, 96 cultures can be measured in less than 1 h; analysis of single cells of a single genotype can be completed in <2 h. FRET-based analysis has been performed with glucose, maltose, ATP and zinc sensors, and it can easily be adapted for high-throughput screening using a wide spectrum of sensors.
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47
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In vivo biochemistry: quantifying ion and metabolite levels in individual cells or cultures of yeast. Biochem J 2011; 438:1-10. [PMID: 21793803 DOI: 10.1042/bj20110428] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Over the past decade, we have learned that cellular processes, including signalling and metabolism, are highly compartmentalized, and that relevant changes in metabolic state can occur at sub-second timescales. Moreover, we have learned that individual cells in populations, or as part of a tissue, exist in different states. If we want to understand metabolic processes and signalling better, it will be necessary to measure biochemical and biophysical responses of individual cells with high temporal and spatial resolution. Fluorescence imaging has revolutionized all aspects of biology since it has the potential to provide information on the cellular and subcellular distribution of ions and metabolites with sub-second time resolution. In the present review we summarize recent progress in quantifying ions and metabolites in populations of yeast cells as well as in individual yeast cells with the help of quantitative fluorescent indicators, namely FRET metabolite sensors. We discuss the opportunities and potential pitfalls and the controls that help preclude misinterpretation.
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Révész K, Tüttő A, Szelényi P, Konta L. Tea flavan-3-ols as modulating factors in endoplasmic reticulum function. Nutr Res 2011; 31:731-40. [DOI: 10.1016/j.nutres.2011.09.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 09/07/2011] [Accepted: 09/15/2011] [Indexed: 01/04/2023]
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49
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Quantitative glucose and ATP sensing in mammalian cells. Pharm Res 2011; 28:2745-57. [PMID: 21691894 DOI: 10.1007/s11095-011-0492-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 05/24/2011] [Indexed: 01/08/2023]
Abstract
The functioning and survival of mammalian cells requires an active energy metabolism. Metabolic dysfunction plays an important role in many human diseases, including diabetes, cancer, inherited mitochondrial disorders, and metabolic syndrome. The monosaccharide glucose constitutes a key source of cellular energy. Following its import across the plasma membrane, glucose is converted into pyruvate by the glycolysis pathway. Pyruvate oxidation supplies substrates for the ATP-generating mitochondrial oxidative phosphorylation (OXPHOS) system. To gain cell-biochemical knowledge about the operation and regulation of the cellular energy metabolism in the healthy and diseased state, quantitative knowledge is required about (changes in) metabolite concentrations under (non) steady-state conditions. This information can, for instance, be used to construct more realistic in silico models of cell metabolism, which facilitates understanding the consequences of metabolic dysfunction as well as on- and off-target effects of mitochondrial drugs. Here we review the current state-of-the-art live-cell quantification of two key cellular metabolites, glucose and ATP, using protein-based sensors. The latter apply the principle of FRET (fluorescence resonance energy transfer) and allow measurements in different cell compartments by fluorescence microscopy. We further summarize the properties and applications of the FRET-based sensors, their calibration, pitfalls, and future perspectives.
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Chaudhuri B, Hörmann F, Frommer WB. Dynamic imaging of glucose flux impedance using FRET sensors in wild-type Arabidopsis plants. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:2411-7. [PMID: 21266495 DOI: 10.1093/jxb/erq444] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Quantitative and dynamic analysis of metabolites and signalling molecules is limited by technical challenges in obtaining temporally resolved information at the cellular and compartmental level. Real-time information on signalling and metabolite levels with subcellular granularity can be obtained with the help of genetically encoded FRET (Förster resonance energy transfer) nanosensors. FRET nanosensors represent powerful tools for gene discovery, and analysis of regulatory networks, for example by screening mutants. However, RNA silencing has impaired our ability to express FRET nanosensors functionally in Arabidopsis plants. This drawback was overcome here by expressing the nanosensors in RNA silencing mutants. However, the use of silencing mutants requires the generation of homozygous lines deficient in RNA silencing as well as the mutation of interest and co-expression of the nanosensor. Here it is shown that dynamic changes in cytosolic glucose levels can readily be quantified in wild-type Arabidopsis plants at early stages of development (7-15 d) before silencing had a major effect on fluorescence intensity. A detailed protocol for screening 10-20 mutant seedlings per day is provided. The detailed imaging protocol provided here is suitable for analysing sugar flux in young wild-type plants as well as mutants affected in sugar signalling, metabolism, or transport using a wide spectrum of FRET nanosensors.
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Affiliation(s)
- Bhavna Chaudhuri
- Department of Plant Biology, Carnegie Institution for Science, 260 Panama Street, Stanford, CA 94305, USA
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