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Papkovsky DB, Kerry JP. Oxygen Sensor-Based Respirometry and the Landscape of Microbial Testing Methods as Applicable to Food and Beverage Matrices. SENSORS (BASEL, SWITZERLAND) 2023; 23:s23094519. [PMID: 37177723 PMCID: PMC10181535 DOI: 10.3390/s23094519] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/19/2023] [Accepted: 04/27/2023] [Indexed: 05/15/2023]
Abstract
The current status of microbiological testing methods for the determination of viable bacteria in complex sample matrices, such as food samples, is the focus of this review. Established methods for the enumeration of microorganisms, particularly, the 'gold standard' agar plating method for the determination of total aerobic viable counts (TVC), bioluminescent detection of total ATP, selective molecular methods (immunoassays, DNA/RNA amplification, sequencing) and instrumental methods (flow cytometry, Raman spectroscopy, mass spectrometry, calorimetry), are analyzed and compared with emerging oxygen sensor-based respirometry techniques. The basic principles of optical O2 sensing and respirometry and the primary materials, detection modes and assay formats employed are described. The existing platforms for bacterial cell respirometry are then described, and examples of particular assays are provided, including the use of rapid TVC tests of food samples and swabs, the toxicological screening and profiling of cells and antimicrobial sterility testing. Overall, O2 sensor-based respirometry and TVC assays have high application potential in the food industry and related areas. They detect viable bacteria via their growth and respiration; the assay is fast (time to result is 2-8 h and dependent on TVC load), operates with complex samples (crude homogenates of food samples) in a simple mix-and-measure format, has low set-up and instrumentation costs and is inexpensive and portable.
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Affiliation(s)
- Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Pharmacy Building, College Road, T12 YT20 Cork, Ireland
| | - Joseph P Kerry
- School of Food and Nutritional Sciences, University College Cork, Microbiology Building, College Road, T12 YT20 Cork, Ireland
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2
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Simon L, Molina PE. Cellular Bioenergetics: Experimental Evidence for Alcohol-induced Adaptations. FUNCTION 2022; 3:zqac039. [PMID: 36120487 PMCID: PMC9469757 DOI: 10.1093/function/zqac039] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 01/07/2023] Open
Abstract
At-risk alcohol use is associated with multisystemic effects and end-organ injury, and significantly contributes to global health burden. Several alcohol-mediated mechanisms have been identified, with bioenergetic maladaptation gaining credence as an underlying pathophysiological mechanism contributing to cellular injury. This evidence-based review focuses on the current knowledge of alcohol-induced bioenergetic adaptations in metabolically active tissues: liver, cardiac and skeletal muscle, pancreas, and brain. Alcohol metabolism itself significantly interferes with bioenergetic pathways in tissues, particularly the liver. Alcohol decreases states of respiration in the electron transport chain, and activity and expression of respiratory complexes, with a net effect to decrease ATP content. In addition, alcohol dysregulates major metabolic pathways, including glycolysis, the tricarboxylic acid cycle, and fatty acid oxidation. These bioenergetic alterations are influenced by alcohol-mediated changes in mitochondrial morphology, biogenesis, and dynamics. The review highlights similarities and differences in bioenergetic adaptations according to tissue type, pattern of (acute vs. chronic) alcohol use, and energy substrate availability. The compromised bioenergetics synergizes with other critical pathophysiological mechanisms, including increased oxidative stress and accelerates cellular dysfunction, promoting senescence, programmed cell death, and end-organ injury.
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Affiliation(s)
- Liz Simon
- Department of Physiology and Comprehensive Alcohol-HIV/AIDS Research Center, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA
| | - Patricia E Molina
- Department of Physiology and Comprehensive Alcohol-HIV/AIDS Research Center, Louisiana State University Health Sciences Center, 1901 Perdido Street, New Orleans, LA 70112, USA
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3
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Schmidt CA, Fisher-Wellman KH, Neufer PD. From OCR and ECAR to energy: Perspectives on the design and interpretation of bioenergetics studies. J Biol Chem 2021; 297:101140. [PMID: 34461088 PMCID: PMC8479256 DOI: 10.1016/j.jbc.2021.101140] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 08/25/2021] [Accepted: 08/26/2021] [Indexed: 12/12/2022] Open
Abstract
Biological energy transduction underlies all physiological phenomena in cells. The metabolic systems that support energy transduction have been of great interest due to their association with numerous pathologies including diabetes, cancer, rare genetic diseases, and aberrant cell death. Commercially available bioenergetics technologies (e.g., extracellular flux analysis, high-resolution respirometry, fluorescent dye kits, etc.) have made practical assessment of metabolic parameters widely accessible. This has facilitated an explosion in the number of studies exploring, in particular, the biological implications of oxygen consumption rate (OCR) and substrate level phosphorylation via glycolysis (i.e., via extracellular acidification rate (ECAR)). Though these technologies have demonstrated substantial utility and broad applicability to cell biology research, they are also susceptible to historical assumptions, experimental limitations, and other caveats that have led to premature and/or erroneous interpretations. This review enumerates various important considerations for designing and interpreting cellular and mitochondrial bioenergetics experiments, some common challenges and pitfalls in data interpretation, and some potential "next steps" to be taken that can address these highlighted challenges.
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Affiliation(s)
- Cameron A Schmidt
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Departments of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA
| | - Kelsey H Fisher-Wellman
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Departments of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
| | - P Darrell Neufer
- East Carolina Diabetes and Obesity Institute, East Carolina University, Greenville, North Carolina, USA; Departments of Physiology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA; Departments of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA.
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4
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Cell Energy Budget Platform for Multiparametric Assessment of Cell and Tissue Metabolism. Methods Mol Biol 2021; 2276:305-324. [PMID: 34060051 DOI: 10.1007/978-1-0716-1266-8_23] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Specific bioenergetic signature reports on the current metabolic state of the cell, which may be affected by metabolic rearrangement, dysfunction or dysregulation of relevant signaling pathways, altered physiological condition or energy stress. A combined analysis of respiration , glycolytic flux, Krebs cycle activity, ATP levels, and total biomass allows informative initial assessment. Such simple, high-throughput, multiparametric methodology, called cell energy budget (CEB ) platform, is presented here and demonstrated with particular cell and tissue models. The CEB uses a commercial fluorescent lanthanide probe pH-Xtra™ to measure extracellular acidification (ECA) associated with lactate (L-ECA) and combined lactate/CO2 (T-ECA), a phosphorescent probe MitoXpress®-Xtra to measure oxygen consumption rate (OCR), a bioluminescent ATP kit, and an absorbance-based total protein assay. All the assays are performed on a standard multi-label reader. Using the same readouts, the CEB approach can be extended to more detailed mechanistic studies, by targeting specific pathways in cell bioenergetics and measuring other cellular parameters, such as NAD(P)H, Ca2+, mitochondrial pH, membrane potential, redox state, with conventional fluorescent or luminescent probes.
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5
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Penjweini R, Roarke B, Alspaugh G, Gevorgyan A, Andreoni A, Pasut A, Sackett DL, Knutson JR. Single cell-based fluorescence lifetime imaging of intracellular oxygenation and metabolism. Redox Biol 2020; 34:101549. [PMID: 32403080 PMCID: PMC7217996 DOI: 10.1016/j.redox.2020.101549] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 04/15/2020] [Accepted: 04/20/2020] [Indexed: 12/02/2022] Open
Abstract
Oxidation-reduction chemistry is fundamental to the metabolism of all living organisms, and hence quantifying the principal redox players is important for a comprehensive understanding of cell metabolism in normal and pathological states. In mammalian cells, this is accomplished by measuring oxygen partial pressure (pO2) in parallel with free and enzyme-bound reduced nicotinamide adenine dinucleotide (phosphate) [H] (NAD(P)H) and flavin adenine dinucleotide (FAD, a proxy for NAD+). Previous optical methods for these measurements had accompanying problems of cytotoxicity, slow speed, population averaging, and inability to measure all redox parameters simultaneously. Herein we present a Förster resonance energy transfer (FRET)-based oxygen sensor, Myoglobin-mCherry, compatible with fluorescence lifetime imaging (FLIM)-based measurement of nicotinamide coenzyme state. This offers a contemporaneous reading of metabolic activity through real-time, non-invasive, cell-by-cell intracellular pO2 and coenzyme status monitoring in living cells. Additionally, this method reveals intracellular spatial heterogeneity and cell-to-cell variation in oxygenation and coenzyme states.
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Affiliation(s)
- Rozhin Penjweini
- Laboratory of Advanced Microscopy and Biophotonics, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Building 10, Room 5D14, Bethesda, MD, 20892-1412, USA
| | - Branden Roarke
- Laboratory of Advanced Microscopy and Biophotonics, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Building 10, Room 5D14, Bethesda, MD, 20892-1412, USA
| | - Greg Alspaugh
- Laboratory of Advanced Microscopy and Biophotonics, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Building 10, Room 5D14, Bethesda, MD, 20892-1412, USA
| | - Anahit Gevorgyan
- Laboratory of Advanced Microscopy and Biophotonics, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Building 10, Room 5D14, Bethesda, MD, 20892-1412, USA
| | - Alessio Andreoni
- Laboratory of Advanced Microscopy and Biophotonics, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Building 10, Room 5D14, Bethesda, MD, 20892-1412, USA; Laboratory of Optical Neurophysiology, Department of Biochemistry and Molecular Medicine, University of California Davis, Tupper Hall, Davis, CA, 95616, USA
| | - Alessandra Pasut
- Laboratory of Angiogenesis and Vascular Metabolism, Center for Cancer Biology, VIB, Leuven Cancer Institute, KU Leuven, Leuven, 3000, Belgium
| | - Dan L Sackett
- Cytoskeletal Dynamics Group, Division of Basic and Translational Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health (NIH), Building 9, Room 1E129, Bethesda, MD, 20892-0924, USA
| | - Jay R Knutson
- Laboratory of Advanced Microscopy and Biophotonics, National Heart, Lung, and Blood Institute (NHLBI), National Institutes of Health (NIH), Building 10, Room 5D14, Bethesda, MD, 20892-1412, USA.
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6
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Pavlacky J, Polak J. Technical Feasibility and Physiological Relevance of Hypoxic Cell Culture Models. Front Endocrinol (Lausanne) 2020; 11:57. [PMID: 32153502 PMCID: PMC7046623 DOI: 10.3389/fendo.2020.00057] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2019] [Accepted: 01/29/2020] [Indexed: 12/13/2022] Open
Abstract
Hypoxia is characterized as insufficient oxygen delivery to tissues and cells in the body and is prevalent in many human physiology processes and diseases. Thus, it is an attractive state to experimentally study to understand its inner mechanisms as well as to develop and test therapies against pathological conditions related to hypoxia. Animal models in vivo fail to recapitulate some of the key hallmarks of human physiology, which leads to human cell cultures; however, they are prone to bias, namely when pericellular oxygen concentration (partial pressure) does not respect oxygen dynamics in vivo. A search of the current literature on the topic revealed this was the case for many original studies pertaining to experimental models of hypoxia in vitro. Therefore, in this review, we present evidence mandating for the close control of oxygen levels in cell culture models of hypoxia. First, we discuss the basic physical laws required for understanding the oxygen dynamics in vitro, most notably the limited diffusion through a liquid medium that hampers the oxygenation of cells in conventional cultures. We then summarize up-to-date knowledge of techniques that help standardize the culture environment in a replicable fashion by increasing oxygen delivery to the cells and measuring pericellular levels. We also discuss how these tools may be applied to model both constant and intermittent hypoxia in a physiologically relevant manner, considering known values of partial pressure of tissue normoxia and hypoxia in vivo, compared to conventional cultures incubated at rigid oxygen pressure. Attention is given to the potential influence of three-dimensional tissue cultures and hypercapnia management on these models. Finally, we discuss the implications of these concepts for cell cultures, which try to emulate tissue normoxia, and conclude that the maintenance of precise oxygen levels is important in any cell culture setting.
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Affiliation(s)
- Jiri Pavlacky
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czechia
- Rare Diseases Research Unit, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University, Prague, Czechia
| | - Jan Polak
- Department of Pathophysiology, Third Faculty of Medicine, Charles University, Prague, Czechia
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7
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Sen R, Hirvonen LM, Zhdanov A, Svihra P, Andersson-Engels S, Nomerotski A, Papkovsky D. New luminescence lifetime macro-imager based on a Tpx3Cam optical camera. BIOMEDICAL OPTICS EXPRESS 2020; 11:77-88. [PMID: 32010501 PMCID: PMC6968763 DOI: 10.1364/boe.11.000077] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 10/16/2019] [Accepted: 10/16/2019] [Indexed: 05/10/2023]
Abstract
The properties of a novel ultra-fast optical imager, Tpx3Cam, were investigated for macroscopic wide-field phosphorescent lifetime imaging (PLIM) applications. The camera is based on a novel optical sensor and Timepix3 readout chip with a time resolution of 1.6 ns, recording of photon arrival time and time over threshold for each pixel, and readout rate of 80 megapixels per second. In this study, we coupled the camera to an image intensifier, a 760 nm emission filter and a 50 mm lens, and with a super-bright 627nm LED providing pulsed excitation of a 18 × 18 mm sample area. The resulting macro-imager with compact and rigid optical alignment of its main components was characterised using planar phosphorescent O2 sensors and a resolution plate mask. Several acquisition and image processing algorithms were evaluated to optimise the system resolution and performance for the wide-field PLIM, followed by imaging a variety of phosphorescent samples. The new PLIM system looks promising, particularly for phosphorescence lifetime-based imaging of O2 in various chemical and biological samples.
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Affiliation(s)
- Rajannya Sen
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
- These authors contributed equally
| | - Liisa M. Hirvonen
- Centre for Microscopy, Characterisation and Analysis (CMCA), The University of Western Australia, Crawley WA 6009, Australia
- These authors contributed equally
| | - Alexander Zhdanov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Peter Svihra
- Department of Physics, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University, Prague 115 19, Czech Republic
- Department of Physics and Astronomy, School of Natural Sciences, The University of Manchester, Manchester M139PL, United Kingdom
| | | | - Andrei Nomerotski
- Physics Department, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Dmitri Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
- Irish Photonics Integration Centre, Tyndall National Institute, Cork, Ireland
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8
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Sheth DB, Gratzl M. Electrochemical mapping of oxygenation in the three-dimensional multicellular tumour hemi-spheroid. Proc Math Phys Eng Sci 2019; 475:20180647. [PMID: 31236040 PMCID: PMC6545061 DOI: 10.1098/rspa.2018.0647] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 04/29/2019] [Indexed: 01/09/2023] Open
Abstract
Blood capillaries deliver oxygen and nutrients to surrounding micro-regions of tissue and carry away metabolic waste. In normal tissue, capillaries are close enough to keep all the cells viable. In solid tumours, the capillary system is chaotic and typical inter-capillary distances are larger than in normal tissue. Therefore, hypoxic regions develop. Drug molecules may not reach these areas at concentrations above the lethal level. The combined effect of low drug concentrations and local hypoxia, often exacerbated by acidity, leads to therapy failure. To better understand the interplay between hypoxia and poor drug penetration, oxygenation needs to be assessed in different areas of inter-capillary tissue. The multicellular tumour spheroid is a well-established three-dimensional (3D) in vitro model of the capillary microenvironment. It is used to mimic nascent tumours and micro-metastases as well. In this work, we demonstrate for the first time that dynamic intra-spheroidal oxygen maps can be obtained at the 3D multicellular tumour hemi-spheroid (MCH) using a non-invasive microelectrode array. The same oxygen distributions exist inside the equivalent but less accessible full spheroid. The MCH makes high throughput-high content analysis of spheroids feasible and thus can assist studies on basic cancer biology, drug development and personalized medicine.
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Affiliation(s)
| | - Miklόs Gratzl
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106, USA
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9
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Andreoni A, Penjweini R, Roarke B, Strub MP, Sackett DL, Knutson JR. Genetically encoded FRET probes for direct mapping and quantification of intracellular oxygenation level via fluorescence lifetime imaging. PROCEEDINGS OF SPIE--THE INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING 2019; 10882:108820O. [PMID: 35046616 PMCID: PMC8765217 DOI: 10.1117/12.2510646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Molecular oxygen is an important reporter of metabolic and physiological status at the cellular and tissue level and its concentration is used for the evaluation of many diseases (e.g.: cancer, coronary artery disease). The development of accurate and quantitative methods to measure O2 concentration ([O2]) in living cells, tissues and organisms is challenging and is subject of intense research. We developed a protein-based, fluorescent oxygen sensor that can be expressed directly in cells to monitor [O2] in the intracellular environment. We fused Myoglobin (Myo), a physiological oxygen carrier, with mCherry, a fluorescent protein, to build a fluorescence resonance energy transfer (FRET) pair, Myo-mCherry. The changes in the spectral properties of Myoglobin upon oxygen binding result in changes of the FRET-depleted emission intensity of mCherry, and this effect is detected by monitoring the fluorescence lifetime of the probe. We present here the preparation and characterization of a series of Myo-mCherry variants and mutants that show the versatility of our protein-based approach: the dynamic range of the sensor is tunable and adaptable to different [O2] ranges, as they occur in vitro in different cell lines, the probe is also easily targeted to subcellular compartments. The use of fluorescence overcomes the most common issues of data collection speed and spatial resolution encountered by currently available methods for O2-monitoring. By using Fluorescence Lifetime Imaging Microscopy (FLIM), we show that we can map the oxygenation level of cells in vitro, providing a quantitative assessment of [O2].
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Affiliation(s)
| | | | | | - Marie-Paule Strub
- Laboratory of Structural Biophysics, Biochemistry and Biophysics Center, National Heart Lung and Blood Institute (NIH)
| | - Dan L Sackett
- Cell Biophysics, National Institute of Child Health and Human Development (NIH)
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10
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Yao M, Sattler T, Rabbani ZN, Pulliam T, Walker G, Gamcsik MP. Mixing and delivery of multiple controlled oxygen environments to a single multiwell culture plate. Am J Physiol Cell Physiol 2018; 315:C766-C775. [PMID: 30183322 DOI: 10.1152/ajpcell.00276.2018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Precise oxygen control is critical to evaluating cell growth, molecular content, and stress response in cultured cells. We have designed, fabricated, and characterized a 96-well plate-based device that is capable of delivering eight static or dynamically changing oxygen environments to different rows on a single plate. The device incorporates a gas-mixing tree that combines two input gases to generate the eight gas mixtures that supply each row of the plate with a different gas atmosphere via a removable manifold. Using air and nitrogen as feed gases, a single 96-well plate can culture cells in applied gas atmospheres with Po2 levels ranging from 1 to 135 mmHg. Human cancer cell lines MCF-7, PANC-1, and Caco-2 were grown on a single plate under this range of oxygen levels. Only cells grown in wells exposed to Po2 ≤37 mmHg express the endogenous hypoxia markers hypoxia-inducible factor-1α and carbonic anhydrase IX. This design is amenable to multiwell plate-based molecular assays or drug dose-response studies in static or cycling hypoxia conditions.
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Affiliation(s)
- Ming Yao
- Department of Mechanical and Aerospace Engineering, North Carolina State University , Raleigh, North Carolina
| | - Tyler Sattler
- University of North Carolina/North Carolina State University Joint Department of Biomedical Engineering, North Carolina State University , Raleigh, North Carolina
| | - Zahid N Rabbani
- University of North Carolina/North Carolina State University Joint Department of Biomedical Engineering, North Carolina State University , Raleigh, North Carolina
| | - Thomas Pulliam
- Department of Chemical and Biomolecular Engineering, North Carolina State University , Raleigh, North Carolina
| | - Glenn Walker
- University of North Carolina/North Carolina State University Joint Department of Biomedical Engineering, North Carolina State University , Raleigh, North Carolina
| | - Michael P Gamcsik
- University of North Carolina/North Carolina State University Joint Department of Biomedical Engineering, North Carolina State University , Raleigh, North Carolina
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Penjweini R, Andreoni A, Rosales T, Kim J, Brenner MD, Sackett DL, Chung JH, Knutson JR. Intracellular oxygen mapping using a myoglobin-mCherry probe with fluorescence lifetime imaging. JOURNAL OF BIOMEDICAL OPTICS 2018; 23:1-14. [PMID: 30298706 PMCID: PMC6210794 DOI: 10.1117/1.jbo.23.10.107001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 09/04/2018] [Indexed: 05/05/2023]
Abstract
Oxygen (O2) is one of the most important biometabolites. In abundance, it serves as the limiting terminus of aerobic respiratory chains in the mitochondria of higher organisms; in deficit, it is a potent determinant of development and regulation of other physiological and therapeutic processes. Most knowledge on intracellular and interstitial concentration ([O2]) is derived from mitochondria isolated from cells or tissue biopsies, providing detailed but nonnative insight into respiratory chain function. The possible loss of essential metabolites during isolation and disruption of the normal interactions of the organelle with the cytoskeleton may cause these data to misrepresent intact cells. Several optical methodologies were also developed, but they are often unable to detect heterogeneity of metabolic characteristics among different individual cells in the same culture, and most cannot detect heterogeneous consumption within different areas of a single cell. Here, we propose a noninvasive and highly sensitive fluorescence lifetime microscopy probe, myoglobin-mCherry, appropriate to intracellular targeting. Using our probe, we monitor mitochondrial contributions to O2 consumption in A549 nonsmall cell lung cancer cells and we reveal heterogeneous [O2] within the intracellular environments. The mitochondrial [O2] at a single-cell level is also mapped by adding a peptide to target the probe to the mitochondria.
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Affiliation(s)
- Rozhin Penjweini
- National Heart, Lung, and Blood Institute, National Institutes of Health, Laboratory of Advanced Microscopy and Biophotonics, Bethesda, Maryland, United States
| | - Alessio Andreoni
- National Heart, Lung, and Blood Institute, National Institutes of Health, Laboratory of Advanced Microscopy and Biophotonics, Bethesda, Maryland, United States
| | - Tilman Rosales
- National Heart, Lung, and Blood Institute, National Institutes of Health, Laboratory of Advanced Microscopy and Biophotonics, Bethesda, Maryland, United States
| | - Jeonghan Kim
- National Heart, Lung, and Blood Institute, National Institutes of Health, Laboratory of Obesity and Aging Research, Bethesda, Maryland, United States
| | - Michael D. Brenner
- National Heart, Lung, and Blood Institute, National Institutes of Health, Laboratory of Advanced Microscopy and Biophotonics, Bethesda, Maryland, United States
| | - Dan L. Sackett
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Cytoskeletal Dynamics Group, Division of Basic and Translational Biophysics, Bethesda, Maryland, United States
| | - Jay H. Chung
- National Heart, Lung, and Blood Institute, National Institutes of Health, Laboratory of Obesity and Aging Research, Bethesda, Maryland, United States
| | - Jay R. Knutson
- National Heart, Lung, and Blood Institute, National Institutes of Health, Laboratory of Advanced Microscopy and Biophotonics, Bethesda, Maryland, United States
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12
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How Supraphysiological Oxygen Levels in Standard Cell Culture Affect Oxygen-Consuming Reactions. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8238459. [PMID: 30363917 PMCID: PMC6186316 DOI: 10.1155/2018/8238459] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 08/01/2018] [Indexed: 12/31/2022]
Abstract
Most mammalian tissue cells experience oxygen partial pressures in vivo equivalent to 1–6% O2 (i.e., physioxia). In standard cell culture, however, headspace O2 levels are usually not actively regulated and under these conditions are ~18%. This drives hyperoxia in cell culture media that can affect a wide variety of cellular activities and may compromise the ability of in vitro models to reproduce in vivo biology. Here, we review and discuss some specific O2-consuming organelles and enzymes, including mitochondria, NADPH oxidases, the transplasma membrane redox system, nitric oxide synthases, xanthine oxidase, and monoamine oxidase with respect to their sensitivities to O2 levels. Many of these produce reactive oxygen and/or nitrogen species (ROS/RNS) as either primary end products or byproducts and are acutely sensitive to O2 levels in the range from 1% to 18%. Interestingly, many of them are also transcriptional targets of hypoxia-inducible factors (HIFs) and chronic cell growth at physioxia versus 18% O2 may alter their expression. Aquaporins, which facilitate hydrogen peroxide diffusion into and out of cells, are also regulated by HIFs, indicating that O2 levels may affect intercellular communication via hydrogen peroxide. The O2 sensitivities of these important activities emphasize the importance of maintaining physioxia in culture.
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Papkovsky DB, Dmitriev RI. Imaging of oxygen and hypoxia in cell and tissue samples. Cell Mol Life Sci 2018; 75:2963-2980. [PMID: 29761206 PMCID: PMC11105559 DOI: 10.1007/s00018-018-2840-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/24/2018] [Accepted: 05/07/2018] [Indexed: 01/17/2023]
Abstract
Molecular oxygen (O2) is a key player in cell mitochondrial function, redox balance and oxidative stress, normal tissue function and many common disease states. Various chemical, physical and biological methods have been proposed for measurement, real-time monitoring and imaging of O2 concentration, state of decreased O2 (hypoxia) and related parameters in cells and tissue. Here, we review the established and emerging optical microscopy techniques allowing to visualize O2 levels in cells and tissue samples, mostly under in vitro and ex vivo, but also under in vivo settings. Particular examples include fluorescent hypoxia stains, fluorescent protein reporter systems, phosphorescent probes and nanosensors of different types. These techniques allow high-resolution mapping of O2 gradients in live or post-mortem tissue, in 2D or 3D, qualitatively or quantitatively. They enable control and monitoring of oxygenation conditions and their correlation with other biomarkers of cell and tissue function. Comparison of these techniques and corresponding imaging setups, their analytical capabilities and typical applications are given.
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Affiliation(s)
- Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
| | - Ruslan I Dmitriev
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
- Institute for Regenerative Medicine, Sechenov University, Moscow, Russian Federation.
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14
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Tiwari A, Wong CS, Nekkanti LP, Deane JA, McDonald C, Li J, Pham Y, Sutherland AE, Jenkin G, Kirkland MA. Controlling the Effective Oxygen Tension Experienced by Cells Using a Dynamic Culture Technique for Hematopoietic Ex Vivo Expansion. ACTA ACUST UNITED AC 2018; 44:2A.11.1-2A.11.13. [PMID: 29512129 DOI: 10.1002/cpsc.42] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Clinical hematopoietic stem/progenitor cell (HSPC) transplantation outcomes are strongly correlated with the number of cells infused. Hence, to generate sufficient HSPCs for transplantation, the best culture parameters for expansion are critical. It is generally assumed that the defined oxygen (O2 ) set for the incubator reflects the pericellular O2 to which cells are being exposed. Studies have shown that low O2 tension maintains an undifferentiated state, but the expansion rate may be constrained because of limited diffusion in a static culture system. A combination of low ambient O2 and dynamic culture conditions has been developed to increase the reconstituting capacity of human HSPCs. In this unit, the protocols for serum-free expansion of HSPCs at 5% and 20% O2 in static and dynamic nutrient flow mode are described. Finally, the impact of O2 tension on HSPC expansion in vitro by flow cytometry and colony forming assays and in vivo through engraftment using a murine model is assessed. © 2018 by John Wiley & Sons, Inc.
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Affiliation(s)
- Abhilasha Tiwari
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Cynthia S Wong
- Institute for Frontier Materials, Deakin University, Geelong, Victoria, Australia
| | - Lakshmi P Nekkanti
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - James A Deane
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Courtney McDonald
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Jingang Li
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Yen Pham
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Amy E Sutherland
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, Victoria, Australia
| | - Graham Jenkin
- The Ritchie Centre, Hudson Institute of Medical Research, Department of Obstetrics & Gynaecology, Southern Clinical School, Monash University, Clayton, Victoria, Australia
| | - Mark A Kirkland
- Institute for Frontier Materials, Deakin University, Geelong, Victoria, Australia
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15
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Okkelman IA, Foley T, Papkovsky DB, Dmitriev RI. Live cell imaging of mouse intestinal organoids reveals heterogeneity in their oxygenation. Biomaterials 2017; 146:86-96. [DOI: 10.1016/j.biomaterials.2017.08.043] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 08/30/2017] [Indexed: 02/06/2023]
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16
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Oxygen imaging of living cells and tissues using luminescent molecular probes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2017. [DOI: 10.1016/j.jphotochemrev.2017.01.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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Zhdanov AV, Okkelman IA, Golubeva AV, Doerr B, Hyland NP, Melgar S, Shanahan F, Cryan JF, Papkovsky DB. Quantitative analysis of mucosal oxygenation using ex vivo imaging of healthy and inflamed mammalian colon tissue. Cell Mol Life Sci 2017; 74:141-151. [PMID: 27510419 PMCID: PMC11107550 DOI: 10.1007/s00018-016-2323-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/14/2016] [Accepted: 08/02/2016] [Indexed: 12/18/2022]
Abstract
Colonic inflammation is associated with decreased tissue oxygenation, significantly affecting gut homeostasis. However, the crosstalk between O2 consumption and supply in the inflamed tissue are not fully understood. Using a murine model of colitis, we analysed O2 in freshly prepared samples of healthy and inflamed colon tissue. We developed protocols for efficient ex vivo staining of mouse distal colon mucosa with a cell-penetrating O2 sensitive probe Pt-Glc and high-resolution imaging of O2 concentration in live tissue by confocal phosphorescence lifetime-imaging microscopy (PLIM). Microscopy analysis revealed that Pt-Glc stained mostly the top 50-60 μm layer of the mucosa, with high phosphorescence intensity in epithelial cells. Measured O2 values in normal mouse tissue ranged between 5 and 35 μM (4-28 Torr), tending to decrease in the deeper tissue areas. Four-day treatment with dextran sulphate sodium (DSS) triggered colon inflammation, as evidenced by an increase in local IL6 and mKC mRNA levels, but did not affect the gross architecture of colonic epithelium. We further observed an increase in oxygenation, partial activation of hypoxia inducible factor (HIF) 1 signalling, and negative trends in pyruvate dehydrogenase activity and O2 consumption rate in the colitis mucosa, suggesting a decrease in mitochondrial respiration, which is known to be regulated via HIF-1 signalling and pyruvate oxidation rate. These results along with efficient staining with Pt-Glc of rat and human colonic mucosa reveal high potential of PLIM platform as a powerful tool for the high-resolution analysis of the intestinal tissue oxygenation in patients with inflammatory bowel disease and other pathologies, affecting tissue respiration.
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Affiliation(s)
- Alexander V Zhdanov
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
| | - Irina A Okkelman
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
| | - Anna V Golubeva
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Barbara Doerr
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
| | - Niall P Hyland
- APC Microbiome Institute, University College Cork, Cork, Ireland
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland
| | - Silvia Melgar
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Fergus Shanahan
- APC Microbiome Institute, University College Cork, Cork, Ireland
| | - John F Cryan
- APC Microbiome Institute, University College Cork, Cork, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
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18
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Papkovsky DB, Zhdanov AV. Phosphorescence based O 2 sensors - Essential tools for monitoring cell and tissue oxygenation and its impact on metabolism. Free Radic Biol Med 2016; 101:202-210. [PMID: 27789291 DOI: 10.1016/j.freeradbiomed.2016.09.018] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 09/13/2016] [Accepted: 09/22/2016] [Indexed: 12/27/2022]
Abstract
Oxygenation condition at the cellular level is a critical factor in tissue physiology and common pathophysiological states including cancer, metabolic disorders, ischemia-reperfusion injury and inflammation. O2 and ROS signalling and hypoxia research are rapidly growing areas spanning life and biomedical sciences, but still many current cell and tissue models and experimental set ups lack physiological relevance, particularly precise control of cellular O2. Quenched-phosphorescence O2 sensing enables implementation of such in situ control of cellular O2 and the creation of physiological conditions in respiring samples analysed in vitro. The advantages of optical O2 sensing are the non-invasive, contactless, real-time, quantitative monitoring of O2 concentration, which can be performed in the gas or liquid phase, macroscopically or microscopically, by point measurement or in imaging mode, with sub-cellular spatial resolution, in a flexible manner and with various cell and tissue models. Significantly, this same technology can also be used to probe the metabolism of cells and tissue under specific oxygenation conditions and their responses to changing conditions. Here we describe the range of available O2 sensing systems and tools, their analytical capabilities, uses in cell/tissue physiology and hypoxia research, and strategies for integration in routine experimental procedures.
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Affiliation(s)
- Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
| | - Alexander V Zhdanov
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
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19
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Zou X, Pan T, Chen L, Tian Y, Zhang W. Luminescence materials for pH and oxygen sensing in microbial cells - structures, optical properties, and biological applications. Crit Rev Biotechnol 2016; 37:723-738. [PMID: 27627832 DOI: 10.1080/07388551.2016.1223011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Luminescence including fluorescence and phosphorescence sensors have been demonstrated to be important for studying cell metabolism, and diagnosing diseases and cancer. Various design principles have been employed for the development of sensors in different formats, such as organic molecules, polymers, polymeric hydrogels, and nanoparticles. The integration of the sensing with fluorescence imaging provides valuable tools for biomedical research and applications at not only bulk-cell level but also at single-cell level. In this article, we critically reviewed recent progresses on pH, oxygen, and dual pH and oxygen sensors specifically for their application in microbial cells. In addition, we focused not only on sensor materials with different chemical structures, but also on design and applications of sensors for better understanding cellular metabolism of microbial cells. Finally, we also provided an outlook for future materials design and key challenges in reaching broad applications in microbial cells.
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Affiliation(s)
- Xianshao Zou
- a Department of Materials Science and Engineering , South University of Science and Technology of China , Shenzhen , Guangdong , P.R. China
| | - Tingting Pan
- a Department of Materials Science and Engineering , South University of Science and Technology of China , Shenzhen , Guangdong , P.R. China
| | - Lei Chen
- b Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology , Tianjin University , Tianjin , P.R. China.,c Key Laboratory of Systems Bioengineering, Ministry of Education of China , Tianjin , P.R. China.,d SynBio Platform, Collaborative Innovation Center of Chemical Science and Engineering , Tianjin , P.R. China
| | - Yanqing Tian
- a Department of Materials Science and Engineering , South University of Science and Technology of China , Shenzhen , Guangdong , P.R. China
| | - Weiwen Zhang
- b Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology , Tianjin University , Tianjin , P.R. China.,c Key Laboratory of Systems Bioengineering, Ministry of Education of China , Tianjin , P.R. China.,d SynBio Platform, Collaborative Innovation Center of Chemical Science and Engineering , Tianjin , P.R. China
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20
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Tiwari A, Wong CS, Nekkanti LP, Deane JA, McDonald C, Jenkin G, Kirkland MA. Impact of Oxygen Levels on Human Hematopoietic Stem and Progenitor Cell Expansion. Stem Cells Dev 2016; 25:1604-1613. [PMID: 27539189 DOI: 10.1089/scd.2016.0153] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Oxygen levels are an important variable during the in vitro culture of stem cells. There has been increasing interest in the use of low oxygen to maximize proliferation and, in some cases, effect differentiation of stem cell populations. It is generally assumed that the defined pO2 in the incubator reflects the pO2 to which the stem cells are being exposed. However, we demonstrate that the pO2 experienced by cells in static culture can change dramatically during the course of culture as cell numbers increase and as the oxygen utilization by cells exceeds the diffusion of oxygen through the media. Dynamic culture (whereby the cell culture plate is in constant motion) largely eliminates this effect, and a combination of low ambient oxygen and dynamic culture results in a fourfold increase in reconstituting capacity of human hematopoietic stem cells compared with those cultured in static culture at ambient oxygen tension. Cells cultured dynamically at 5% oxygen exhibited the best expansion: 30-fold increase by flow cytometry, 120-fold increase by colony assay, and 11% of human CD45 engraftment in the bone marrow of NOD/SCID mice. To our knowledge, this is the first study to compare individual and combined effects of oxygen and static or dynamic culture on hematopoietic ex vivo expansion. Understanding and controlling the effective oxygen tension experienced by cells may be important in clinical stem cell expansion systems, and these results may have relevance to the interpretation of low oxygen culture studies.
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Affiliation(s)
- Abhilasha Tiwari
- 1 The Ritchie Centre, Hudson Institute of Medical Research , Clayton, Australia
| | | | - Lakshmi P Nekkanti
- 1 The Ritchie Centre, Hudson Institute of Medical Research , Clayton, Australia
| | - James A Deane
- 1 The Ritchie Centre, Hudson Institute of Medical Research , Clayton, Australia .,3 Department of Obstetrics and Gynaecology, Southern Clinical School, Monash University , Clayton, Australia
| | - Courtney McDonald
- 1 The Ritchie Centre, Hudson Institute of Medical Research , Clayton, Australia
| | - Graham Jenkin
- 1 The Ritchie Centre, Hudson Institute of Medical Research , Clayton, Australia .,3 Department of Obstetrics and Gynaecology, Southern Clinical School, Monash University , Clayton, Australia
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21
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Weiszenstein M, Musutova M, Plihalova A, Westlake K, Elkalaf M, Koc M, Prochazka A, Pala J, Gulati S, Trnka J, Polak J. Adipogenesis, lipogenesis and lipolysis is stimulated by mild but not severe hypoxia in 3T3-L1 cells. Biochem Biophys Res Commun 2016; 478:727-32. [PMID: 27498031 DOI: 10.1016/j.bbrc.2016.08.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 08/03/2016] [Indexed: 02/09/2023]
Abstract
In-vitro investigation of the effects of hypoxia is limited by physical laws of gas diffusion and cellular O2 consumption, making prolonged exposures to stable O2 concentrations impossible. Using a gas-permeable cultureware, chronic effects of mild and severe hypoxia on triglyceride accumulation, lipid droplet size distribution, spontaneous lipolysis and gene expression of adipocyte-specific markers were assessed. 3T3-L1 cells were differentiated under 20%, 4% or 1% O2 using a gas-permeable cultureware. Triglyceride accumulation, expression of genes characteristic for advanced adipocyte differentiation and involvement of key lipogenesis enzymes were assessed after exposures. Lipogenesis increased by 375% under mild hypoxia, but dropped by 43% in severe hypoxia. Mild, but not severe, hypoxia increased formation of large lipid droplets 6.4 fold and strongly induced gene expression of adipocyte-specific markers. Spontaneous lipolysis increased by 488% in mild, but only by 135% in severe hypoxia. Inhibition of ATP-dependent citrate lyase suppressed hypoxia-induced lipogenesis by 81% and 85%. Activation of HIF inhibited lipogenesis by 59%. Mild, but not severe, hypoxia stimulates lipolysis and promotes adipocyte differentiation, probably through excess of acetyl-CoA originating from tricarboxylic acid cycle independently of HIF activation.
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Affiliation(s)
- Martin Weiszenstein
- Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic
| | - Martina Musutova
- Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic
| | - Andrea Plihalova
- Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic
| | - Katerina Westlake
- Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic; Center of Toxicology and Health Safety, The National Institute of Public Health, Srobarova 48, Prague, Czech Republic
| | - Moustafa Elkalaf
- Laboratory for Metabolism and Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic
| | - Michal Koc
- Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic
| | - Antonin Prochazka
- Institute of Biophysics and Informatics, First Faculty of Medicine, Charles University in Prague, Salmovska 1, Prague, Czech Republic
| | - Jan Pala
- Department of Sport Medicine, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic
| | - Sumeet Gulati
- Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic
| | - Jan Trnka
- Laboratory for Metabolism and Bioenergetics, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic
| | - Jan Polak
- Center for Research on Diabetes, Metabolism and Nutrition, Third Faculty of Medicine, Charles University in Prague, Ruska 87, Prague, Czech Republic; Center of Toxicology and Health Safety, The National Institute of Public Health, Srobarova 48, Prague, Czech Republic.
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22
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The Ca2+/Mn2+-transporting SPCA2 pump is regulated by oxygen and cell density in colon cancer cells. Biochem J 2016; 473:2507-18. [PMID: 27316461 DOI: 10.1042/bcj20160477] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 06/17/2016] [Indexed: 12/18/2022]
Abstract
The mammalian SPCA1 and SPCA2 ATPases localize in membranes of the secretory pathway and transport ions of Ca(2+) and Mn(2+) The role of tissue-specific SPCA2 isoform, highly expressed in lungs, mammary gland and gastrointestinal tract, is poorly understood. To elucidate the function of SPCA2, we studied human colon cancer HCT116 cells, grown under ambient and decreased O2 levels. We found that in contrast with other Ca(2+)-ATPase isoforms the expression of SPCA2 was up-regulated under hypoxia (3% O2), in both adherent (2D) and spheroid (3D) cultures. In spheroids, experiencing lowest O2 levels (30-50 μM, measured by phosphorescence lifetime imaging microscopy), we observed lower staining with reactive oxygen species (ROS)-specific fluorescent probe, which correlated with increased SPCA2. However, SPCA2 expression was up-regulated in cells exposed to reactive oxygen and nitrogen species donors, and when grown at higher density. We noticed that the culture exposed to hypoxia showed overall increase in S phase-positive cells and hypothesized that SPCA2 up-regulation under hypoxia can be linked to Mn(2+)-dependent cell cycle arrest. Consequently, we found that SPCA2-transfected cells display a higher number of cells entering S phase. Altogether, our results point at the important role of SPCA2 in regulation of cell cycle in cancer cells.
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23
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Zhdanov AV, Golubeva AV, Okkelman IA, Cryan JF, Papkovsky DB. Imaging of oxygen gradients in giant umbrella cells: an ex vivo PLIM study. Am J Physiol Cell Physiol 2015; 309:C501-9. [DOI: 10.1152/ajpcell.00121.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 08/03/2015] [Indexed: 12/29/2022]
Abstract
O2 plays a pivotal role in aerobic metabolism and regulation of cell and tissue function. Local differences and fluctuations in tissue O2 levels are well documented; however, the physiological significance of O2 microgradients, particularly at the subcellular level, remains poorly understood. Using the cell-penetrating phosphorescent O2 probe Pt-Glc and confocal fluorescence microscopy, we visualized O2 distribution in individual giant (>100-μm) umbrella cells located superficially in the urinary bladder epithelium. We optimized conditions for in vivo phosphorescent staining of the inner surface of the mouse bladder and subsequent ex vivo analysis of excised live tissue. Imaging experiments revealed significant (≤85 μM) and heterogeneous deoxygenation within respiring umbrella cells, with radial O2 gradients of up to 40 μM across the cell, or ∼0.6 μM/μm. Deeply deoxygenated (5–15 μM O2) regions were seen to correspond to the areas enriched with polarized mitochondria. Pharmacological activation of mitochondrial respiration decreased oxygenation and O2 gradients in umbrella cells, while inhibition with antimycin A dissipated the gradients and caused gradual reoxygenation of the tissue to ambient levels. Detailed three-dimensional maps of O2 distribution potentially can be used for the modeling of intracellular O2-dependent enzymatic reactions and downstream processes, such as hypoxia-inducible factor signaling. Further ex vivo and in vivo studies on intracellular and tissue O2 gradients using confocal imaging can shed light on the molecular mechanisms regulating O2-dependent (patho)physiological processes in the bladder and other tissues.
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Affiliation(s)
- A. V. Zhdanov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - A. V. Golubeva
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; and
| | - I. A. Okkelman
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - J. F. Cryan
- Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland; and
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - D. B. Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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24
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Dmitriev RI, Papkovsky DB. Intracellular probes for imaging oxygen concentration: how good are they? Methods Appl Fluoresc 2015; 3:034001. [DOI: 10.1088/2050-6120/3/3/034001] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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25
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Jenkins J, Dmitriev RI, Morten K, McDermott KW, Papkovsky DB. Oxygen-sensing scaffolds for 3-dimensional cell and tissue culture. Acta Biomater 2015; 16:126-35. [PMID: 25653216 DOI: 10.1016/j.actbio.2015.01.032] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 01/21/2015] [Accepted: 01/22/2015] [Indexed: 10/24/2022]
Abstract
Porous membrane scaffolds are widely used materials for three-dimensional cell cultures and tissue models. Additional functional modification of such scaffolds can significantly extend their use and operational performance. Here we describe hybrid microporous polystyrene-based scaffolds impregnated with a phosphorescent O2-sensitive dye PtTFPP, optimized for live cell fluorescence microscopy and imaging of O2 distribution in cultured cells. Modified scaffolds possess high brightness, convenient spectral characteristics (534 nm excitation, 650 nm emission), stable and robust response to pO2 in phosphorescence intensity and lifetime imaging modes (>twofold response over 21/0% O2), such as confocal PLIM. They are suitable for prolonged use under standard culturing conditions without affecting cell viability, and for multi-parametric imaging analysis of cultured cells and tissue samples. We tested the O2 scaffolds with cultured cancer cells (HCT116), multicellular aggregates (PC12) and rat brain slices and showed that they can inform on tissue oxygenation at different depths and cell densities, changes in respiration activity, viability and responses to drug treatment. Using this method multiplexed with staining of dead cells (CellTox Green) and active mitochondria (TMRM), we demonstrated that decreased O2 (20-24 μM) in scaffold corresponds to highest expression of tyrosine hydroxylase in PC12 cells. Such hypoxia is also beneficial for action of hypoxia-specific anti-cancer drug tirapazamine (TPZ). Thus, O2 scaffolds allow for better control of conditions in 3D tissue cultures, and are useful for a broad range of biomaterials and physiological studies.
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26
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Yoshihara T, Hosaka M, Terata M, Ichikawa K, Murayama S, Tanaka A, Mori M, Itabashi H, Takeuchi T, Tobita S. Intracellular and in Vivo Oxygen Sensing Using Phosphorescent Ir(III) Complexes with a Modified Acetylacetonato Ligand. Anal Chem 2015; 87:2710-7. [DOI: 10.1021/ac5040067] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Toshitada Yoshihara
- Department
of Chemistry and Chemical Biology, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Masahiro Hosaka
- Department
of Biotechnology, Akita Prefectural University, Shimoshinjo, Akita 010-0195, Japan
| | - Motoki Terata
- Department
of Biotechnology, Akita Prefectural University, Shimoshinjo, Akita 010-0195, Japan
| | - Kazuki Ichikawa
- Department
of Chemistry and Chemical Biology, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Saori Murayama
- Department
of Chemistry and Chemical Biology, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Asami Tanaka
- Department
of Chemistry and Chemical Biology, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Masanobu Mori
- Department
of Environmental Engineering Science, Gunma University, Kiryu, Gunma 376-8515, Japan
| | - Hideyuki Itabashi
- Department
of Environmental Engineering Science, Gunma University, Kiryu, Gunma 376-8515, Japan
| | | | - Seiji Tobita
- Department
of Chemistry and Chemical Biology, Gunma University, Kiryu, Gunma 376-8515, Japan
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27
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Papkovsky DB, Zhdanov AV. Cell energy budget platform for assessment of cell metabolism. Methods Mol Biol 2015; 1265:333-48. [PMID: 25634285 DOI: 10.1007/978-1-4939-2288-8_23] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Changes in bioenergetic parameters report on metabolic rearrangement, dysfunction of major pathways, and regulatory processes within the cell, adaptation to energy stress, or new physiological condition. A combined measurement of oxidative phosphorylation, glycolytic flux, the Krebs cycle activity, ATP levels, and total biomass allows detailed metabolic assessment. We describe a simple methodology for high-throughput multiparametric assessment of cell bioenergetics, called cell energy budget (CEB) platform, and demonstrate its practical use with cell models. The CEB relies on a standard multi-label reader with time-resolved fluorescence capabilities, the lanthanide probe pH-Xtra™ to measure extracellular acidification (ECA) associated with lactate (L-ECA) and combined lactate/CO2 (T-ECA) extrusion, the phosphorescent probe MitoXpress®-Xtra to measure oxygen consumption rate (OCR), the bioluminescent total ATP assay, and absorbance-based total protein assay. This approach can be further extended with the measurement of other cellular parameters, such as NAD(P)H, Ca(2+), mitochondrial pH, membrane potential, and redox state, using the corresponding fluorescent or luminescent probes.
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Affiliation(s)
- Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, Office 1.28, College Road, Cork, Ireland,
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28
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Dmitriev RI, Borisov SM, Kondrashina AV, Pakan JMP, Anilkumar U, Prehn JHM, Zhdanov AV, McDermott KW, Klimant I, Papkovsky DB. Imaging oxygen in neural cell and tissue models by means of anionic cell-permeable phosphorescent nanoparticles. Cell Mol Life Sci 2015; 72:367-81. [PMID: 25006059 PMCID: PMC11113450 DOI: 10.1007/s00018-014-1673-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 06/20/2014] [Accepted: 06/23/2014] [Indexed: 11/30/2022]
Abstract
Cell-permeable phosphorescent probes enable the study of cell and tissue oxygenation, bioenergetics, metabolism, and pathological states such as stroke and hypoxia. A number of such probes have been described in recent years, the majority consisting of cationic small molecule and nanoparticle structures. While these probes continue to advance, adequate staining for the study of certain cell types using live imaging techniques remains elusive; this is particularly true for neural cells. Here we introduce novel probes for the analysis of neural cells and tissues: negatively charged poly(methyl methacrylate-co-methacrylic acid)-based nanoparticles impregnated with a phosphorescent Pt(II)-tetrakis(pentafluorophenyl)porphyrin (PtPFPP) dye (this form is referred to as PA1), and with an additional reference/antennae dye poly(9,9-diheptylfluorene-alt-9,9-di-p-tolyl-9H-fluorene) (this form is referred to as PA2). PA1 and PA2 are internalised by endocytosis, result in efficient staining in primary neurons, astrocytes, and PC12 cells and multi-cellular aggregates, and allow for the monitoring of local O(2) levels on a time-resolved fluorescence plate reader and PLIM microscope. PA2 also efficiently stains rat brain slices and permits detailed O(2) imaging experiments using both one and two-photon intensity-based modes and PLIM modes. Multiplexed analysis of embryonic rat brain slices reveals age-dependent staining patterns for PA2 and a highly heterogeneous distribution of O(2) in tissues, which we relate to the localisation of specific progenitor cell populations. Overall, these anionic probes are useful for sensing O(2) levels in various cells and tissues, particularly in neural cells, and facilitate high-resolution imaging of O(2) in 3D tissue models.
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Affiliation(s)
- Ruslan I Dmitriev
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland,
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Zhdanov AV, Waters AHC, Golubeva AV, Papkovsky DB. Differential contribution of key metabolic substrates and cellular oxygen in HIF signalling. Exp Cell Res 2014; 330:13-28. [PMID: 25447307 DOI: 10.1016/j.yexcr.2014.10.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 10/02/2014] [Accepted: 10/05/2014] [Indexed: 12/25/2022]
Abstract
Changes in availability and utilisation of O2 and metabolic substrates are common in ischemia and cancer. We examined effects of substrate deprivation on HIF signalling in PC12 cells exposed to different atmospheric O2. Upon 2-4h moderate hypoxia, HIF-α protein levels were dictated by the availability of glutamine and glucose, essential for deep cell deoxygenation and glycolytic ATP flux. Nuclear accumulation of HIF-1α dramatically decreased upon inhibition of glutaminolysis or glutamine deprivation. Elevation of HIF-2α levels was transcription-independent and associated with the activation of Akt and Erk1/2. Upon 2h anoxia, HIF-2α levels strongly correlated with cellular ATP, produced exclusively via glycolysis. Without glucose, HIF signalling was suppressed, giving way to other regulators of cell adaptation to energy crisis, e.g. AMPK. Consequently, viability of cells deprived of O2 and glucose decreased upon inhibition of AMPK with dorsomorphin. The capacity of cells to accumulate HIF-2α decreased after 24h glucose deprivation. This effect, associated with increased AMPKα phosphorylation, was sensitive to dorsomorphin. In chronically hypoxic cells, glutamine played no major role in HIF-2α accumulation, which became mainly glucose-dependent. Overall, the availability of O2 and metabolic substrates intricately regulates HIF signalling by affecting cell oxygenation, ATP levels and pathways involved in production of HIF-α.
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Affiliation(s)
- Alexander V Zhdanov
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
| | - Alicia H C Waters
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
| | - Anna V Golubeva
- Alimentary Pharmabiotic Centre, University College Cork, Bioscience Institute, Western Road, Cork, Ireland
| | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland
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Kondrashina AV, Ogurtsov VI, Papkovsky DB. Comparison of the three optical platforms for measurement of cellular respiration. Anal Biochem 2014; 468:1-3. [PMID: 25233002 DOI: 10.1016/j.ab.2014.09.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 08/29/2014] [Accepted: 09/04/2014] [Indexed: 11/29/2022]
Abstract
We compared three optical platforms for measurement of cellular respiration: absolute oxygen consumption rates (OCRs) in hermetically sealed microcuvettes, relative OCRs measured in a 96-well plate with oil seal, and steady-state oxygenation of cells in an open 96-well plate. Using mouse embryonic fibroblasts cell line, the phosphorescent intracellular O2 probe MitoXpress-Intra, and time-resolved fluorescence reader, we determined algorithms for conversion of relative OCRs and cell oxygenation into absolute OCRs, thereby allowing simple high-throughput measurement of absolute OCR values.
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Affiliation(s)
- Alina V Kondrashina
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | | | - Dmitri B Papkovsky
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.
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31
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Dmitriev RI, Kondrashina AV, Koren K, Klimant I, Zhdanov AV, Pakan JMP, McDermott KW, Papkovsky DB. Small molecule phosphorescent probes for O2imaging in 3D tissue models. Biomater Sci 2014; 2:853-866. [DOI: 10.1039/c3bm60272a] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
PtPFPP-carbohydrate conjugates are promising O2probes for 3D PLIM imaging of live spheroids and brain explants.
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Affiliation(s)
| | | | - Klaus Koren
- Institute of Analytical Chemistry and Food Chemistry
- Graz University of Technology
- 8010 Graz, Austria
| | - Ingo Klimant
- Institute of Analytical Chemistry and Food Chemistry
- Graz University of Technology
- 8010 Graz, Austria
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32
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Zhdanov AV, Dmitriev RI, Hynes J, Papkovsky DB. Kinetic Analysis of Local Oxygenation and Respiratory Responses of Mammalian Cells Using Intracellular Oxygen-Sensitive Probes and Time-Resolved Fluorometry. Methods Enzymol 2014; 542:183-207. [DOI: 10.1016/b978-0-12-416618-9.00010-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Dmitriev RI, Zhdanov AV, Nolan YM, Papkovsky DB. Imaging of neurosphere oxygenation with phosphorescent probes. Biomaterials 2013; 34:9307-17. [DOI: 10.1016/j.biomaterials.2013.08.065] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 08/21/2013] [Indexed: 02/04/2023]
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Zhdanov AV, Waters AHC, Golubeva AV, Dmitriev RI, Papkovsky DB. Availability of the key metabolic substrates dictates the respiratory response of cancer cells to the mitochondrial uncoupling. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2013; 1837:51-62. [PMID: 23891695 DOI: 10.1016/j.bbabio.2013.07.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 07/16/2013] [Accepted: 07/17/2013] [Indexed: 12/12/2022]
Abstract
Active glycolysis and glutaminolysis provide bioenergetic stability of cancer cells in physiological conditions. Under hypoxia, metabolic and mitochondrial disorders, or pharmacological treatment, a deficit of key metabolic substrates may become life-threatening to cancer cells. We analysed the effects of mitochondrial uncoupling by FCCP on the respiration of cells fed by different combinations of Glc, Gal, Gln and Pyr. In cancer PC12 and HCT116 cells, a large increase in O2 consumption rate (OCR) upon uncoupling was only seen when Gln was combined with either Glc or Pyr. Inhibition of glutaminolysis with BPTES abolished this effect. Despite the key role of Gln, addition of FCCP inhibited respiration and induced apoptosis in cells supplied with Gln alone or Gal/Gln. For all substrate combinations, amplitude of respiratory responses to FCCP did not correlate with Akt, Erk and AMPK phosphorylation, cellular ATP, and resting OCR, mitochondrial Ca(2+) or membrane potential. However, we propose that proton motive force could modulate respiratory response to FCCP by regulating mitochondrial transport of Gln and Pyr, which decreases upon mitochondrial depolarisation. As a result, an increase in respiration upon uncoupling is abolished in cells, deprived of Gln or Pyr (Glc). Unlike PC12 or HCT116 cells, mouse embryonic fibroblasts were capable of generating pronounced response to FCCP when deprived of Gln, thus exhibiting lower dependence on glutaminolysis. Overall, the differential regulation of the respiratory response to FCCP by metabolic environment suggests that mitochondrial uncoupling has a potential for substrate-specific inhibition of cell function, and can be explored for selective cancer treatment.
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Affiliation(s)
- Alexander V Zhdanov
- Biochemistry Department, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Ireland.
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Chronic hypoxia leads to a glycolytic phenotype and suppressed HIF-2 signaling in PC12 cells. Biochim Biophys Acta Gen Subj 2013; 1830:3553-69. [DOI: 10.1016/j.bbagen.2013.02.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 01/22/2013] [Accepted: 02/15/2013] [Indexed: 12/12/2022]
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36
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Bafilomycin A1 activates HIF-dependent signalling in human colon cancer cells via mitochondrial uncoupling. Biosci Rep 2013; 32:587-95. [PMID: 22943412 PMCID: PMC3497721 DOI: 10.1042/bsr20120085] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Mitochondrial uncoupling is implicated in many patho(physiological) states. Using confocal live cell imaging and an optical O2 sensing technique, we show that moderate uncoupling of the mitochondria with plecomacrolide Baf (bafilomycin A1) causes partial depolarization of the mitochondria and deep sustained deoxygenation of human colon cancer HCT116 cells subjected to 6% atmospheric O2. A decrease in iO2 (intracellular O2) to 0–10 μM, induced by Baf, is sufficient for stabilization of HIFs (hypoxia inducible factors) HIF-1α and HIF-2α, coupled with an increased expression of target genes including GLUT1 (glucose transporter 1), HIF PHD2 (prolyl hydroxylase domain 2) and CAIX (carbonic anhydrase IX). Under the same hypoxic conditions, treatment with Baf causes neither decrease in iO2 nor HIF-α stabilization in the low-respiring HCT116 cells deficient in COX (cytochrome c-oxidase). Both cell types display equal capacities for HIF-α stabilization by hypoxia mimetics DMOG (dimethyloxalylglycine) and CoCl2, thus suggesting that the effect of Baf under hypoxia is driven mainly by mitochondrial respiration. Altogether, by activating HIF signalling under moderate hypoxia, mitochondrial uncoupling can play an important regulatory role in colon cancer metabolism and modulate adaptation of cancer cells to natural hypoxic environments.
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Kondrashina AV, Papkovsky DB, Dmitriev RI. Measurement of cell respiration and oxygenation in standard multichannel biochips using phosphorescent O2-sensitive probes. Analyst 2013; 138:4915-21. [DOI: 10.1039/c3an00658a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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39
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Oxygen versus Reactive Oxygen in the Regulation of HIF-1α: The Balance Tips. Biochem Res Int 2012; 2012:436981. [PMID: 23091723 PMCID: PMC3474226 DOI: 10.1155/2012/436981] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 09/14/2012] [Accepted: 09/15/2012] [Indexed: 12/02/2022] Open
Abstract
Hypoxia inducible factor (HIF) is known as the master regulator of the cellular response to hypoxia and is of pivotal importance during development as well as in human disease, particularly in cancer. It is composed of a constitutively expressed β subunit (HIF-1β) and an oxygen-regulated α subunit (HIF-1α and HIF-2α), whose stability is tightly controlled by a family of oxygen- and iron-dependent prolyl hydroxylase enzymes. Whether or not mitochondria-derived reactive oxygen species (ROS) are involved in the regulation of Hypoxia Inducible Factor-1α has been a matter of contention for the last 10 years, with equally compelling evidence in favor and against their contribution. A number of recent papers appear to tip the balance against a role for ROS. Thus, it has been demonstrated that HIF prolyl hydroxylases are unlikely to be physiological targets of ROS and that the increase in ROS that is associated with downregulation of Thioredoxin Reductase in hypoxia does not affect HIF-1α stabilization. Finally, the protein CHCHD4, which modulates cellular HIF-1α concentrations by promoting mitochondrial electron transport chain activity, has been proposed to exert its regulatory effect by affecting cellular oxygen availability. These reports are consistent with the hypothesis that mitochondria play a critical role in the regulation of HIF-1α by controlling intracellular oxygen concentrations.
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Dmitriev RI, Zhdanov AV, Jasionek G, Papkovsky DB. Assessment of Cellular Oxygen Gradients with a Panel of Phosphorescent Oxygen-Sensitive Probes. Anal Chem 2012; 84:2930-8. [DOI: 10.1021/ac3000144] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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41
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Optical probes and techniques for O2 measurement in live cells and tissue. Cell Mol Life Sci 2012; 69:2025-39. [PMID: 22249195 PMCID: PMC3371327 DOI: 10.1007/s00018-011-0914-0] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Revised: 12/19/2011] [Accepted: 12/29/2011] [Indexed: 01/03/2023]
Abstract
In recent years, significant progress has been achieved in the sensing and imaging of molecular oxygen (O2) in biological samples containing live cells and tissue. We review recent developments in the measurement of O2 in such samples by optical means, particularly using the phosphorescence quenching technique. The main types of soluble O2 sensors are assessed, including small molecule, supramolecular and particle-based structures used as extracellular or intracellular probes in conjunction with different detection modalities and measurement formats. For the different O2 sensing systems, particular attention is paid to their merits and limitations, analytical performance, general convenience and applicability in specific biological applications. The latter include measurement of O2 consumption rate, sample oxygenation, sensing of intracellular O2, metabolic assessment of cells, and O2 imaging of tissue, vasculature and individual cells. Altogether, this gives the potential user a comprehensive guide for the proper selection of the appropriate optical probe(s) and detection platform to suit their particular biological applications and measurement requirements.
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Fercher A, Zhdanov AV, Papkovsky DB. O2 Imaging in Biological Specimens. PHOSPHORESCENT OXYGEN-SENSITIVE PROBES 2012. [DOI: 10.1007/978-3-0348-0525-4_3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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43
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Dmitriev RI, Ropiak HM, Ponomarev GV, Yashunsky DV, Papkovsky DB. Cell-Penetrating Conjugates of Coproporphyrins with Oligoarginine Peptides: Rational Design and Application for Sensing Intracellular O2. Bioconjug Chem 2011; 22:2507-18. [DOI: 10.1021/bc200324q] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Ruslan I. Dmitriev
- Biochemistry Department, University College Cork, Cavanagh Pharmacy Building,
Cork, Ireland
| | - Honorata M. Ropiak
- Biochemistry Department, University College Cork, Cavanagh Pharmacy Building,
Cork, Ireland
| | - Gelii V. Ponomarev
- Institute
of Biomedical Chemistry, Russian Academy of Medical Sciences, Pogodinskaia Ul.
10/2, 119992 Moscow, Russia
| | - Dmitri V. Yashunsky
- Institute
of Biomedical Chemistry, Russian Academy of Medical Sciences, Pogodinskaia Ul.
10/2, 119992 Moscow, Russia
| | - Dmitri B. Papkovsky
- Biochemistry Department, University College Cork, Cavanagh Pharmacy Building,
Cork, Ireland
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44
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Takahashi E, Sato M. Imaging of oxygen gradients in monolayer cultured cells using green fluorescent protein. Am J Physiol Cell Physiol 2010; 299:C1318-23. [DOI: 10.1152/ajpcell.00254.2010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Gradients of Po2 between capillary blood and mitochondria are the driving force for diffusional O2 delivery in tissues. Hypoxic microenvironments in tissues that result from diffusional O2 gradients are especially relevant in solid tumors because they have been related to a poor prognosis. To address the impact of tissue O2 gradients, we developed a novel technique that permits imaging of intracellular O2 levels in cultured cells at a subcellular spatial resolution. This was done, with the sensitivity to O2 ≤3%, by the O2-dependent red shift of green fluorescent protein (AcGFP1) fluorescence. Measurements were carried out in a confluent monolayer of Hep3B cells expressing AcGFP1 in the cytoplasm. To establish a two-dimensional O2 diffusion model, a thin quartz glass slip was placed onto the monolayer cells to prevent O2 diffusion from the top surface of the cell layer. The magnitude of the red shift progressively increased as the distance from the gas coverslip interface increased. It reached an anoxic level in cells located at ∼220 μm and ∼690 μm from the gas coverslip boundary at 1% and 3% gas phase O2, respectively. Thus the average O2 gradient was 0.03 mmHg/μm in the present tissue model. Abolition of mitochondrial respiration significantly dampened the gradients. Furthermore, intracellular gradients of the red shift in mitochondria-targeted AcGFP1 in single Hep3B cells suggest that the origin of tissue O2 gradients is intracellular. Findings in the present two-dimensional O2 diffusion model support the crucial role of tissue O2 diffusion in defining the O2 microenvironment in individual cells.
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Affiliation(s)
- Eiji Takahashi
- Biomedical Engineering Course, Advanced Technology Fusion, Graduate School of Science and Engineering, Saga University, Saga, Japan and
| | - Michihiko Sato
- CLRE, Yamagata University School of Medicine, Yamagata, Japan
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Zhdanov AV, Dmitriev RI, Papkovsky DB. Bafilomycin A1 activates respiration of neuronal cells via uncoupling associated with flickering depolarization of mitochondria. Cell Mol Life Sci 2010; 68:903-17. [PMID: 20820851 PMCID: PMC3037485 DOI: 10.1007/s00018-010-0502-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 07/08/2010] [Accepted: 08/06/2010] [Indexed: 10/27/2022]
Abstract
Bafilomycin A1 (Baf) induces an elevation of cytosolic Ca(2+) and acidification in neuronal cells via inhibition of the V-ATPase. Also, Baf uncouples mitochondria in differentiated PC12 ((d)PC12), (d)SH-SY5Y cells and cerebellar granule neurons, and markedly elevates their respiration. This respiratory response in (d)PC12 is accompanied by morphological changes in the mitochondria and decreases the mitochondrial pH, Ca(2+) and ΔΨm. The response to Baf is regulated by cytosolic Ca(2+) fluxes from the endoplasmic reticulum. Inhibition of permeability transition pore opening increases the depolarizing effect of Baf on the ΔΨm. Baf induces stochastic flickering of the ΔΨm with a period of 20 ± 10 s. Under conditions of suppressed ATP production by glycolysis, oxidative phosphorylation impaired by Baf does not provide cells with sufficient ATP levels. Cells treated with Baf become more susceptible to excitation with KCl. Such mitochondrial uncoupling may play a role in a number of (patho)physiological conditions induced by Baf.
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Affiliation(s)
- Alexander V Zhdanov
- Biochemistry Department, University College Cork, Cavanagh Pharmacy Building, College Road, Cork, Republic of Ireland.
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