1
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Steinhoff JS, Wagner C, Dähnhardt HE, Košić K, Meng Y, Taschler U, Pajed L, Yang N, Wulff S, Kiefer MF, Petricek KM, Flores RE, Li C, Dittrich S, Sommerfeld M, Guillou H, Henze A, Raila J, Wowro SJ, Schoiswohl G, Lass A, Schupp M. Adipocyte HSL is required for maintaining circulating vitamin A and RBP4 levels during fasting. EMBO Rep 2024:10.1038/s44319-024-00158-x. [PMID: 38769419 DOI: 10.1038/s44319-024-00158-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/19/2024] [Accepted: 04/30/2024] [Indexed: 05/22/2024] Open
Abstract
Vitamin A (retinol) is distributed via the blood bound to its specific carrier protein, retinol-binding protein 4 (RBP4). Retinol-loaded RBP4 is secreted into the circulation exclusively from hepatocytes, thereby mobilizing hepatic retinoid stores that represent the major vitamin A reserves in the body. The relevance of extrahepatic retinoid stores for circulating retinol and RBP4 levels that are usually kept within narrow physiological limits is unknown. Here, we show that fasting affects retinoid mobilization in a tissue-specific manner, and that hormone-sensitive lipase (HSL) in adipose tissue is required to maintain serum concentrations of retinol and RBP4 during fasting in mice. We found that extracellular retinol-free apo-RBP4 induces retinol release by adipocytes in an HSL-dependent manner. Consistently, global or adipocyte-specific HSL deficiency leads to an accumulation of retinoids in adipose tissue and a drop of serum retinol and RBP4 during fasting, which affects retinoid-responsive gene expression in eye and kidney and lowers renal retinoid content. These findings establish a novel crosstalk between liver and adipose tissue retinoid stores for the maintenance of systemic vitamin A homeostasis during fasting.
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Affiliation(s)
- Julia S Steinhoff
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Carina Wagner
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Henriette E Dähnhardt
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Kristina Košić
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Yueming Meng
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Ulrike Taschler
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Laura Pajed
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria
| | - Na Yang
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Sascha Wulff
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Marie F Kiefer
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Konstantin M Petricek
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Roberto E Flores
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Chen Li
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Sarah Dittrich
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Manuela Sommerfeld
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Hervé Guillou
- Toxalim (Research Center in Food Toxicology), INRAE, ENVT, INP- PURPAN, UMR 1331, UPS, Université de Toulouse, Toulouse, France
| | - Andrea Henze
- Martin Luther University Halle-Wittenberg, Institute of Agricultural and Nutritional Sciences, Halle, Germany
- Junior Research Group ProAID, Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany
| | - Jens Raila
- Department of Physiology and Pathophysiology, Institute of Nutritional Science, University of Potsdam, Nuthetal, Germany
| | - Sylvia J Wowro
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany
| | - Gabriele Schoiswohl
- Gottfried Schatz Research Center, Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biosciences, NAWI Graz, University of Graz, Graz, Austria.
- BioTechMed-Graz, Graz, Austria.
| | - Michael Schupp
- Charité Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Institute of Pharmacology, Max Rubner Center (MRC) for Cardiovascular-Metabolic-Renal Research, Berlin, Germany.
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2
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TeSlaa T, Ralser M, Fan J, Rabinowitz JD. The pentose phosphate pathway in health and disease. Nat Metab 2023; 5:1275-1289. [PMID: 37612403 DOI: 10.1038/s42255-023-00863-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 07/12/2023] [Indexed: 08/25/2023]
Abstract
The pentose phosphate pathway (PPP) is a glucose-oxidizing pathway that runs in parallel to upper glycolysis to produce ribose 5-phosphate and nicotinamide adenine dinucleotide phosphate (NADPH). Ribose 5-phosphate is used for nucleotide synthesis, while NADPH is involved in redox homoeostasis as well as in promoting biosynthetic processes, such as the synthesis of tetrahydrofolate, deoxyribonucleotides, proline, fatty acids and cholesterol. Through NADPH, the PPP plays a critical role in suppressing oxidative stress, including in certain cancers, in which PPP inhibition may be therapeutically useful. Conversely, PPP-derived NADPH also supports purposeful cellular generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) for signalling and pathogen killing. Genetic deficiencies in the PPP occur relatively commonly in the committed pathway enzyme glucose-6-phosphate dehydrogenase (G6PD). G6PD deficiency typically manifests as haemolytic anaemia due to red cell oxidative damage but, in severe cases, also results in infections due to lack of leucocyte oxidative burst, highlighting the dual redox roles of the pathway in free radical production and detoxification. This Review discusses the PPP in mammals, covering its roles in biochemistry, physiology and disease.
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Affiliation(s)
- Tara TeSlaa
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
| | - Markus Ralser
- Department of Biochemistry, Charité Universitätsmedizin, Berlin, Germany
- The Wellcome Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK
- Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Jing Fan
- Morgride Institute for Research, Madison, WI, USA
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Joshua D Rabinowitz
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
- Department of Chemistry, Princeton University, Princeton, NJ, USA.
- Ludwig Institute for Cancer Research, Princeton Branch, Princeton, NJ, USA.
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3
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Evolution Shapes the Gene Expression Response to Oxidative Stress. Int J Mol Sci 2019; 20:ijms20123040. [PMID: 31234431 PMCID: PMC6627103 DOI: 10.3390/ijms20123040] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Revised: 06/14/2019] [Accepted: 06/18/2019] [Indexed: 12/12/2022] Open
Abstract
Reactive oxygen species (ROS) play a key role in cell physiology and function. ROS represents a potential source of damage for many macromolecules including DNA. It is thought that daily changes in oxidative stress levels were an important early factor driving evolution of the circadian clock which enables organisms to predict changes in ROS levels before they actually occur and thereby optimally coordinate survival strategies. It is clear that ROS, at relatively low levels, can serve as an important signaling molecule and also serves as a key regulator of gene expression. Therefore, the mechanisms that have evolved to survive or harness these effects of ROS are ancient evolutionary adaptations that are tightly interconnected with most aspects of cellular physiology. Our understanding of these mechanisms has been mainly based on studies using a relatively small group of genetic models. However, we know comparatively little about how these mechanisms are conserved or have adapted during evolution under different environmental conditions. In this review, we describe recent work that has revealed significant species-specific differences in the gene expression response to ROS by exploring diverse organisms. This evidence supports the notion that during evolution, rather than being highly conserved, there is inherent plasticity in the molecular mechanisms responding to oxidative stress.
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4
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Reichmann D, Voth W, Jakob U. Maintaining a Healthy Proteome during Oxidative Stress. Mol Cell 2019; 69:203-213. [PMID: 29351842 DOI: 10.1016/j.molcel.2017.12.021] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 12/11/2017] [Accepted: 12/21/2017] [Indexed: 12/11/2022]
Abstract
Some of the most challenging stress conditions that organisms encounter during their lifetime involve the transient accumulation of reactive oxygen and chlorine species. Extremely reactive to amino acid side chains, these oxidants cause widespread protein unfolding and aggregation. It is therefore not surprising that cells draw on a variety of different strategies to counteract the damage and maintain a healthy proteome. Orchestrated largely by direct changes in the thiol oxidation status of key proteins, the response strategies involve all layers of protein protection. Reprogramming of basic biological functions helps decrease nascent protein synthesis and restore redox homeostasis. Mobilization of oxidative stress-activated chaperones and production of stress-resistant non-proteinaceous chaperones prevent irreversible protein aggregation. Finally, redox-controlled increase in proteasome activity removes any irreversibly damaged proteins. Together, these systems pave the way to restore protein homeostasis and enable organisms to survive stress conditions that are inevitable when living an aerobic lifestyle.
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Affiliation(s)
- Dana Reichmann
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Safra Campus Givat Ram, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
| | - Wilhelm Voth
- Department of Molecular, Cellular, and Developmental Biology and Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-1048, USA
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology and Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109-1048, USA.
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5
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Peoples JNR, Maxmillian T, Le Q, Nadtochiy SM, Brookes PS, Porter GA, Davidson VL, Ebert SN. Metabolomics reveals critical adrenergic regulatory checkpoints in glycolysis and pentose-phosphate pathways in embryonic heart. J Biol Chem 2018. [PMID: 29540484 DOI: 10.1074/jbc.ra118.002566] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Cardiac energy demands during early embryonic periods are sufficiently met through glycolysis, but as development proceeds, the oxidative phosphorylation in mitochondria becomes increasingly vital. Adrenergic hormones are known to stimulate metabolism in adult mammals and are essential for embryonic development, but relatively little is known about their effects on metabolism in the embryonic heart. Here, we show that embryos lacking adrenergic stimulation have ∼10-fold less cardiac ATP compared with littermate controls. Despite this deficit in steady-state ATP, neither the rates of ATP formation nor degradation was affected in adrenergic hormone-deficient hearts, suggesting that ATP synthesis and hydrolysis mechanisms were fully operational. We thus hypothesized that adrenergic hormones stimulate metabolism of glucose to provide chemical substrates for oxidation in mitochondria. To test this hypothesis, we employed a metabolomics-based approach using LC/MS. Our results showed glucose 1-phosphate and glucose 6-phosphate concentrations were not significantly altered, but several downstream metabolites in both glycolytic and pentose-phosphate pathways were significantly lower compared with controls. Furthermore, we identified glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase as key enzymes in those respective metabolic pathways whose activity was significantly (p < 0.05) and substantially (80 and 40%, respectively) lower in adrenergic hormone-deficient hearts. Addition of pyruvate and to a lesser extent ribose led to significant recovery of steady-state ATP concentrations. These results demonstrate that without adrenergic stimulation, glucose metabolism in the embryonic heart is severely impaired in multiple pathways, ultimately leading to insufficient metabolic substrate availability for successful transition to aerobic respiration needed for survival.
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Affiliation(s)
- Jessica N R Peoples
- From the Burnett School of Biomedical Sciences, Division of Metabolic and Cardiovascular Sciences, University of Central Florida, College of Medicine, Orlando, Florida 32827
| | - Timmi Maxmillian
- From the Burnett School of Biomedical Sciences, Division of Metabolic and Cardiovascular Sciences, University of Central Florida, College of Medicine, Orlando, Florida 32827
| | - Quynh Le
- From the Burnett School of Biomedical Sciences, Division of Metabolic and Cardiovascular Sciences, University of Central Florida, College of Medicine, Orlando, Florida 32827
| | - Sergiy M Nadtochiy
- the Department of Anesthesiology, University of Rochester Medical Center, Rochester, New York 14620, and
| | - Paul S Brookes
- From the Burnett School of Biomedical Sciences, Division of Metabolic and Cardiovascular Sciences, University of Central Florida, College of Medicine, Orlando, Florida 32827
| | - George A Porter
- the Department of Pediatrics, Division of Cardiology, University of Rochester Medical Center, Rochester, New York 14642
| | - Victor L Davidson
- From the Burnett School of Biomedical Sciences, Division of Metabolic and Cardiovascular Sciences, University of Central Florida, College of Medicine, Orlando, Florida 32827
| | - Steven N Ebert
- From the Burnett School of Biomedical Sciences, Division of Metabolic and Cardiovascular Sciences, University of Central Florida, College of Medicine, Orlando, Florida 32827,
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6
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Abstract
Diabetic embryopathy is a theoretical enigma and a clinical challenge. Both type 1 and type 2 diabetic pregnancy carry a significant risk for fetal maldevelopment, and the precise reasons for the diabetes-induced teratogenicity are not clearly identified. The experimental work in this field has revealed a partial, however complex, answer to the teratological question, and we will review some of the latest suggestions.
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Affiliation(s)
- Ulf J. Eriksson
- CONTACT Ulf J. Eriksson Department of Medical Cell Biology, Uppsala University, Biomedical Center, PO Box 571, SE-751 23 Uppsala, Sweden
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7
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Programmed regulation of rat offspring adipogenic transcription factor (PPARγ) by maternal nutrition. J Dev Orig Health Dis 2015; 6:530-8. [PMID: 26286138 DOI: 10.1017/s2040174415001440] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We determined the protein expression of adipogenic transcription factor, peroxisome proliferator-activated receptor gamma (PPARγ) and its co-repressor and co-activator complexes in adipose tissue from the obese offspring of under- and over-nourished dams. Female rats were fed either a high-fat (60% kcal) or control (10% kcal) diet before mating, and throughout pregnancy and lactation (Mat-OB). Additional dams were 50% food-restricted from pregnancy day 10 to term [intrauterine growth-restricted (IUGR)]. Adipose tissue protein expression was analyzed in newborn and adult male offspring. Normal birth weight Mat-OB and low birth weight IUGR newborns had upregulated PPARγ with variable changes in co-repressors and co-activators. As obese adults, Mat-OB and IUGR offspring had increased PPARγ with decreased co-repressor and increased co-activator expression. Nutritionally programmed increased PPARγ expression is associated with altered expression of its co-regulators in the newborn and adult offspring. Functional studies of PPARγ co-regulators are necessary to establish their role in PPARγ-mediated programmed obesity.
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8
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Intasqui P, Antoniassi MP, Camargo M, Nichi M, Carvalho VM, Cardozo KHM, Zylbersztejn DS, Bertolla RP. Differences in the seminal plasma proteome are associated with oxidative stress levels in men with normal semen parameters. Fertil Steril 2015; 104:292-301. [DOI: 10.1016/j.fertnstert.2015.04.037] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 04/29/2015] [Accepted: 04/29/2015] [Indexed: 10/23/2022]
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9
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Eichmann TO, Lass A. DAG tales: the multiple faces of diacylglycerol--stereochemistry, metabolism, and signaling. Cell Mol Life Sci 2015; 72:3931-52. [PMID: 26153463 PMCID: PMC4575688 DOI: 10.1007/s00018-015-1982-3] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 06/17/2015] [Accepted: 06/29/2015] [Indexed: 12/31/2022]
Abstract
The neutral lipids diacylglycerols (DAGs) are involved in a plethora of metabolic pathways. They function as components of cellular membranes, as building blocks for glycero(phospho)lipids, and as lipid second messengers. Considering their central role in multiple metabolic processes and signaling pathways, cellular DAG levels require a tight regulation to ensure a constant and controlled availability. Interestingly, DAG species are versatile in their chemical structure. Besides the different fatty acid species esterified to the glycerol backbone, DAGs can occur in three different stereo/regioisoforms, each with unique biological properties. Recent scientific advances have revealed that DAG metabolizing enzymes generate and distinguish different DAG isoforms, and that only one DAG isoform holds signaling properties. Herein, we review the current knowledge of DAG stereochemistry and their impact on cellular metabolism and signaling. Further, we describe intracellular DAG turnover and its stereochemistry in a 3-pool model to illustrate the spatial and stereochemical separation and hereby the diversity of cellular DAG metabolism.
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Affiliation(s)
- Thomas Oliver Eichmann
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010, Graz, Austria.
| | - Achim Lass
- Institute of Molecular Biosciences, University of Graz, Heinrichstrasse 31/2, 8010, Graz, Austria.
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10
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Light Effect on Water Viscosity: Implication for ATP Biosynthesis. Sci Rep 2015; 5:12029. [PMID: 26154113 PMCID: PMC4495567 DOI: 10.1038/srep12029] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 06/09/2015] [Indexed: 01/07/2023] Open
Abstract
Previous work assumed that ATP synthase, the smallest known rotary motor in nature, operates at 100% efficiency. Calculations which arrive to this result assume that the water viscosity inside mitochondria is constant and corresponds to that of bulk water. In our opinion this assumption is not satisfactory for two reasons: (1) There is evidence that the water in mitochondria prevails to 100% as interfacial water. (2) Laboratory experiments which explore the properties of interfacial water suggest viscosities which exceed those of bulk water, specifically at hydrophilic interfaces. Here, we wish to suggest a physicochemical mechanism which assumes intramitochondrial water viscosity gradients and consistently explains two cellular responses: The decrease and increase in ATP synthesis in response to reactive oxygen species and non-destructive levels of near-infrared (NIR) laser light, respectively. The mechanism is derived from the results of a new experimental method, which combines the technique of nanoindentation with the modulation of interfacial water layers by laser irradiation. Results, including the elucidation of the principle of light-induced ATP production, are expected to have broad implications in all fields of medicine.
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11
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Abstract
The heart is a very special organ in the body and has a high requirement for metabolism due to its constant workload. As a consequence, to provide a consistent and sufficient energy a high steady-state demand of metabolism is required by the heart. When delicately balanced mechanisms are changed by physiological or pathophysiological conditions, the whole system's homeostasis will be altered to a new balance, which contributes to the pathologic process. So it is no wonder that almost every heart disease is related to metabolic shift. Furthermore, aging is also found to be related to the reduction in mitochondrial function, insulin resistance, and dysregulated intracellular lipid metabolism. Adenosine monophosphate-activated protein kinase (AMPK) functions as an energy sensor to detect intracellular ATP/AMP ratio and plays a pivotal role in intracellular adaptation to energy stress. During different pathology (like myocardial ischemia and hypertension), the activation of cardiac AMPK appears to be essential for repairing cardiomyocyte's function by accelerating ATP generation, attenuating ATP depletion, and protecting the myocardium against cardiac dysfunction and apoptosis. In this overview, we will talk about the normal heart's metabolism, how metabolic shifts during aging and different pathologies, and how AMPK regulates metabolic changes during these conditions.
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Affiliation(s)
- Yina Ma
- Department of Pharmacology and Toxicology, State University of New York at Buffalo, NY 14214
| | - Ji Li
- Department of Pharmacology and Toxicology, State University of New York at Buffalo, NY 14214
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12
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Hohnholt MC, Blumrich EM, Dringen R. Multiassay analysis of the toxic potential of hydrogen peroxide on cultured neurons. J Neurosci Res 2014; 93:1127-37. [PMID: 25354694 DOI: 10.1002/jnr.23502] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Revised: 09/19/2014] [Accepted: 09/25/2014] [Indexed: 11/10/2022]
Abstract
To clarify discrepancies in the literature on the adverse effects of hydrogen peroxide on neurons, this study investigated the application of this peroxide to cultured cerebellar granule neurons with six assays frequently used to test for viability. Cultured neurons efficiently cleared exogenous H2O2. Although viability was not affected by exposure to 10 µM hydrogen peroxide, an exposure to the peroxide in higher concentrations rapidly lowered, within 15 min, the cellular 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltertrazolium bromide (MTT) reduction capacity to 53% ± 1% (100 µM) and 31% ± 1% (1,000 µM) and the 3-amino-7-dimethylamino-2-methyl-phenazine hydrochloride (neutral red; NR) uptake to 84% ± 6% (100 µM) and 33% ± 1% (1,000 µM) of control cells. The release of glycolytically generated lactate was stopped within 30 min in neurons treated with 1,000 µM peroxide. In contrast, even hours after peroxide application, the cell morphology, the number of propidium iodide-positive cells, and the extracellular activity of the cytosolic enzyme lactate dehydrogenase (LDH) were not significantly altered. The rapid loss in MTT reduction and NR uptake after exposure of neurons to H2O2 for 5 or 15 min correlated well with a strongly compromised MTT reduction and a very high extracellular LDH activity observed after further incubation in peroxide-free medium for a total incubation period of 24 hr. These data demonstrate that cultured neurons do not recover from damage that is inflicted by a short exposure to H2O2 and that the rapid losses in the capacities of neurons for MTT reduction and NR uptake are good predictors of delayed cell damage.
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Affiliation(s)
- Michaela C Hohnholt
- Centre for Biomolecular Interactions Bremen and Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany
| | - Eva M Blumrich
- Centre for Biomolecular Interactions Bremen and Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany
| | - Ralf Dringen
- Centre for Biomolecular Interactions Bremen and Centre for Environmental Research and Sustainable Technology, University of Bremen, Bremen, Germany
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13
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Vanzo E, Ghirardo A, Merl-Pham J, Lindermayr C, Heller W, Hauck SM, Durner J, Schnitzler JP. S-nitroso-proteome in poplar leaves in response to acute ozone stress. PLoS One 2014; 9:e106886. [PMID: 25192423 PMCID: PMC4156402 DOI: 10.1371/journal.pone.0106886] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 08/01/2014] [Indexed: 11/26/2022] Open
Abstract
Protein S-nitrosylation, the covalent binding of nitric oxide (NO) to protein cysteine residues, is one of the main mechanisms of NO signaling in plant and animal cells. Using a combination of the biotin switch assay and label-free LC-MS/MS analysis, we revealed the S-nitroso-proteome of the woody model plant Populus x canescens. Under normal conditions, constitutively S-nitrosylated proteins in poplar leaves and calli comprise all aspects of primary and secondary metabolism. Acute ozone fumigation was applied to elicit ROS-mediated changes of the S-nitroso-proteome. This treatment changed the total nitrite and nitrosothiol contents of poplar leaves and affected the homeostasis of 32 S-nitrosylated proteins. Multivariate data analysis revealed that ozone exposure negatively affected the S-nitrosylation status of leaf proteins: 23 proteins were de-nitrosylated and 9 proteins had increased S-nitrosylation content compared to the control. Phenylalanine ammonia-lyase 2 (log2[ozone/control] = −3.6) and caffeic acid O-methyltransferase (−3.4), key enzymes catalyzing important steps in the phenylpropanoid and subsequent lignin biosynthetic pathways, respectively, were de-nitrosylated upon ozone stress. Measuring the in vivo and in vitro phenylalanine ammonia-lyase activity indicated that the increase of the phenylalanine ammonia-lyase activity in response to acute ozone is partly regulated by de-nitrosylation, which might favor a higher metabolic flux through the phenylpropanoid pathway within minutes after ozone exposure.
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Affiliation(s)
- Elisa Vanzo
- Research Unit Environmental Simulation, Institute for Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Andrea Ghirardo
- Research Unit Environmental Simulation, Institute for Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Juliane Merl-Pham
- Research Unit Protein Science, Helmholtz Zentrum München, Neuherberg, Germany
| | - Christian Lindermayr
- Institute for Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Werner Heller
- Institute for Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Stefanie M. Hauck
- Research Unit Protein Science, Helmholtz Zentrum München, Neuherberg, Germany
| | - Jörg Durner
- Institute for Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Jörg-Peter Schnitzler
- Research Unit Environmental Simulation, Institute for Biochemical Plant Pathology, Helmholtz Zentrum München, Neuherberg, Germany
- * E-mail:
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14
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Protective effect of quercetin on hyperglycemia, oxidative stress and DNA damage in alloxan induced type 2 diabetic mice. Life Sci 2014; 109:8-14. [PMID: 24946265 DOI: 10.1016/j.lfs.2014.06.005] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Revised: 05/28/2014] [Accepted: 06/06/2014] [Indexed: 12/20/2022]
Abstract
AIMS Quercetin is a natural polyphenolic flavonoid and acts as a quencher for reactive oxygen species generated by any physical or chemical action. In type 2 diabetes mellitus (T2DM) the basic characteristic feature is hyperglycemia which leads to complications involving oxidative stress. In view of this, the present study was conducted to examine the effect of quercetin in T2DM. MAIN METHODS A total of 18 mice were divided into three groups, vis control, diabetic and diabetic treated with quercetin. Fasting blood glucose (FBG) levels and anti-oxidant enzyme activity were assayed. Creatinine, urea, lipid peroxidation, GLUT4 expression and DNA damage were also measured. KEY FINDINGS A significant decrease in FBG level and liver and kidney marker enzymes was observed in the quercetin treated group as compared to the diabetic one. Glutathione, SOD, catalase, and glutathione-S-transferase levels were also found to be increased on quercetin supplementation. Thiobarbituric acid-reactive substance level was decreased while GLUT4 expression levels were increased in the treated group. DNA damage was also affected positively by quercetin when subjected with single cell alkaline gel electrophoresis. Thus, we may suggest an anti-oxidant potential and protective effect of quercetin in T2DM mice. SIGNIFICANCE From this study, we conclude that quercetin ameliorates hyperglycemia and oxidative stress, by blunting free radical induced toxicity in T2DM.
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GAPDH: the missing link between glycolysis and mitochondrial oxidative phosphorylation? Biochem Soc Trans 2014; 41:1294-7. [PMID: 24059522 DOI: 10.1042/bst20130067] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The main function of glycolysis and oxidative phosphorylation is to produce cellular energy in the form of ATP. In the present paper we propose a link between both of these energy-regulatory processes in the form of GAPDH (glyceraldehyde-3-phosphate dehydrogenase) and CytOx (cytochrome c oxidase). GAPDH is the sixth enzyme of glycolysis, whereas CytOx is the fourth complex of the mitochondrial oxidative phosphorylation system. In MS analysis, GAPDH was found to be associated with a BN-PAGE (blue native PAGE)-isolated complex of CytOx from bovine heart tissue homogenates. Both GAPDH and CytOx are highly regulated under normal energy metabolic conditions, but both of these enzymes are highly deregulated in the presence of oxidative stress. The interaction of GAPDH with CytOx could be the point of interest as it has already been shown that GAPDH protein damage results in a marked decrease in cellular ATP levels. On the other hand, decreasing the ATP/ADP ratio may ultimately result in switching off the allosteric ATP inhibition of CytOx leading to increased ROS (reactive oxygen species), cytochrome c release and apoptosis. Moreover, we have previously reported that allosteric ATP inhibition of CytOx is responsible for keeping the membrane potential at low healthy values, thus avoiding the production of ROS and this allosteric ATP inhibition is switched on at a high ATP/ADP ratio. So, in the present paper, we propose a scheme that could prove to be a link between these two enzymes and their role in the prevalence of diseases.
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MacKay H, Khazall R, Patterson ZR, Wellman M, Abizaid A. Rats perinatally exposed to food restriction and high-fat diet show differences in adipose tissue gene expression under chronic caloric restriction. Adipocyte 2013; 2:237-45. [PMID: 24052899 PMCID: PMC3774699 DOI: 10.4161/adip.24752] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 04/12/2013] [Accepted: 04/19/2013] [Indexed: 11/24/2022] Open
Abstract
The aim of this study is to analyze how maternal diet during the lactational period influences the adipose tissue response to chronic caloric restriction in offspring. Lactating dams were subjected to one of three treatments: 50% food restriction (FR), ad lib standard chow (AL), or ad lib high-fat diet (HF). Juveniles were first weaned onto standard chow, then in adulthood 50% calorically restricted and maintained at 90% of normal body weight for 60 d. HF animals showed increased percent body fat compared with AL and FR animals despite equivalent body weights. HF animals showed alterations in the balance of adipose tissue lipogenic (FAS, LPL) and lipolytic (HSL) gene expression that may underlie their propensity to maintain fat stores under caloric restriction.
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UCP2 inhibition triggers ROS-dependent nuclear translocation of GAPDH and autophagic cell death in pancreatic adenocarcinoma cells. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:672-9. [PMID: 23124112 DOI: 10.1016/j.bbamcr.2012.10.028] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 10/19/2012] [Accepted: 10/25/2012] [Indexed: 12/12/2022]
Abstract
Mitochondrial uncoupling protein 2 (UCP2) can moderate oxidative stress by favoring the influx of protons into the mitochondrial matrix, thus reducing electron leakage from respiratory chain and mitochondrial superoxide production. Here, we demonstrate that UCP2 inhibition by genipin or UCP2 siRNA strongly increases reactive oxygen species (ROS) production inhibiting pancreatic adenocarcinoma cell growth. We also show that UCP2 inhibition triggers ROS-dependent nuclear translocation of the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH), formation of autophagosomes, and the expression of the autophagy marker LC3-II. Consistently, UCP2 over-expression significantly reduces basal autophagy confirming the anti-autophagic role of UCP2. Furthermore, we demonstrate that autophagy induced by UCP2 inhibition determines a ROS-dependent cell death, as indicated by the apoptosis decrease in the presence of the autophagy inhibitors chloroquine (CQ) or 3-methyladenine (3-MA), or the radical scavenger NAC. Intriguingly, the autophagy induced by genipin is able to potentiate the autophagic cell death triggered by gemcitabine, the standard chemotherapeutic drug for pancreatic adenocarcinoma, supporting the development of an anti-cancer therapy based on UCP2 inhibition associated to standard chemotherapy. Our results demonstrate for the first time that UCP2 plays a role in autophagy regulation bringing new insights into mitochondrial uncoupling protein field.
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Abstract
Hypertension is a leading cause of morbidity and mortality worldwide. Individuals with hypertension are at an increased risk for stroke, heart disease and kidney failure. Essential hypertension results from a combination of genetic and lifestyle factors. One such lifestyle factor is diet, and its role in the control of blood pressure has come under much scrutiny. Just as increased salt and sugar are known to elevate blood pressure, other dietary factors may have antihypertensive effects. Studies including the Optimal Macronutrient Intake to Prevent Heart Disease (OmniHeart) study, Multiple Risk Factor Intervention Trial (MRFIT), International Study of Salt and Blood Pressure (INTERSALT) and Dietary Approaches to Stop Hypertension (DASH) study have demonstrated an inverse relationship between dietary protein and blood pressure. One component of dietary protein that may partially account for its antihypertensive effect is the nonessential amino acid cysteine. Studies in hypertensive humans and animal models of hypertension have shown that N-acetylcysteine, a stable cysteine analogue, lowers blood pressure, which substantiates this idea. Cysteine may exert its antihypertensive effects directly or through its storage form, glutathione, by decreasing oxidative stress, improving insulin resistance and glucose metabolism, lowering advanced glycation end products, and modulating levels of nitric oxide and other vasoactive molecules. Therefore, adopting a balanced diet containing cysteine-rich proteins may be a beneficial lifestyle choice for individuals with hypertension. An example of such a diet is the DASH diet, which is low in salt and saturated fat; includes whole grains, poultry, fish and nuts; and is rich in vegetables, fruits and low-fat dairy products.
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Affiliation(s)
- Sudesh Vasdev
- Discipline of Medicine, Faculty of Medicine, Health Sciences Centre, Memorial University, St John's, Newfoundland
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D’Cruz SC, Jubendradass R, Mathur PP. Bisphenol A Induces Oxidative Stress and Decreases Levels of Insulin Receptor Substrate 2 and Glucose Transporter 8 in Rat Testis. Reprod Sci 2011; 19:163-72. [DOI: 10.1177/1933719111415547] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Shereen C. D’Cruz
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Pondicherry, India
| | - R. Jubendradass
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Pondicherry, India
| | - Premendu P. Mathur
- Department of Biochemistry and Molecular Biology, School of Life Sciences, Pondicherry University, Pondicherry, India
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20
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Krüger A, Grüning NM, Wamelink MMC, Kerick M, Kirpy A, Parkhomchuk D, Bluemlein K, Schweiger MR, Soldatov A, Lehrach H, Jakobs C, Ralser M. The pentose phosphate pathway is a metabolic redox sensor and regulates transcription during the antioxidant response. Antioxid Redox Signal 2011; 15:311-24. [PMID: 21348809 DOI: 10.1089/ars.2010.3797] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
AIMS A shift in primary carbon metabolism is the fastest response to oxidative stress. Induced within seconds, it precedes transcriptional regulation, and produces reducing equivalents in form of NADPH within the pentose phosphate pathway (PPP). RESULTS Here, we provide evidence for a regulatory signaling function of this metabolic transition in yeast. Several PPP-deficiencies caused abnormal accumulation of intermediate metabolites during the stress response. These PPP-deficient strains had strong growth deficits on media containing oxidants, but we observed that part of their oxidant-phenotypes were not attributable to the production of NADPH equivalents. This pointed to a second, yet unknown role of the PPP in the antioxidant response. Comparing transcriptome profiles obtained by RNA sequencing, we found gene expression profiles that resembled oxidative conditions when PPP activity was increased. Vice versa, deletion of PPP enzymes disturbed and delayed mRNA and protein expression during the antioxidant response. INNOVATION Thus, the transient activation of the PPP is a metabolic signal required for balancing and timing gene expression upon an oxidative burst. CONCLUSION Consequently, dynamic rearrangements in central carbon metabolism seem to be of major importance for eukaryotic redox sensing, and represent a novel class of dynamic gene expression regulators.
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Affiliation(s)
- Antje Krüger
- Max Planck Institute for Molecular Genetics, Berlin, Germany
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21
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Morita N, Lee JH, Bapat A, Fishbein MC, Mandel WJ, Chen PS, Weiss JN, Karagueuzian HS. Glycolytic inhibition causes spontaneous ventricular fibrillation in aged hearts. Am J Physiol Heart Circ Physiol 2011; 301:H180-91. [PMID: 21478408 DOI: 10.1152/ajpheart.00128.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Selective glycolytic inhibition (GI) promotes electromechanical alternans and triggered beats in isolated cardiac myocytes. We sought to determine whether GI promotes triggered activity by early afterdepolarization (EAD) or delayed afterdepolarizations in intact hearts isolated from adult and aged rats. Dual voltage and intracellular calcium ion (Ca(i)(2+)) fluorescent optical maps and single cell glass microelectrode recordings were made from the left ventricular (LV) epicardium of isolated Langendorff-perfused adult (∼4 mo) and aged (∼24 mo) rat hearts. GI was induced by replacing glucose with 10 mM pyruvate in oxygenated Tyrode's. Within 20 min, GI slowed Ca(i)(2+) transient decline rate and shortened action potential duration in both groups. These changes were associated with ventricular fibrillation (VF) in the aged hearts (64 out of 66) but not in adult hearts (0 out of 18; P < 0.001). VF was preceded by a transient period of focal ventricular tachycardia caused by EAD-mediated triggered activity leading to VF within seconds. The VF was suppressed by the ATP-sensitive K (K(ATP)) channel blocker glibenclamide (1 μM) but not (0 out of 7) by mitochondrial K(ATP) block. The Ca-calmodulin-dependent protein kinase II (CaMKII) blocker KN-93 (1 μM) prevented GI-mediated VF (P < 0.05). Block of Na-Ca exchanger (NCX) by SEA0400 (2 μM) prevented GI-mediated VF (3 out of 6), provided significant bradycardia did not occur. Aged hearts had significantly greater LV fibrosis and reduced connexin 43 than adult hearts (P < 0.05). We conclude that in aged fibrotic unlike in adult rat hearts, GI promotes EADs, triggered activity, and VF by activation of K(ATP) channels CaMKII and NCX.
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Affiliation(s)
- Norishige Morita
- Translational Arrhythmia Research Section, Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 675 Charles E. Young Dr. South, MRL 3645 Mail Code: 176022, Los Angeles, CA 90095, USA
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Han C, Wen X, Zheng Q, Li H. Effect of starvation on activities and mRNA expression of lipoprotein lipase and hormone-sensitive lipase in tilapia (Oreochromis niloticus x O. areus). FISH PHYSIOLOGY AND BIOCHEMISTRY 2011; 37:113-122. [PMID: 20706869 DOI: 10.1007/s10695-010-9423-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2010] [Accepted: 07/29/2010] [Indexed: 05/29/2023]
Abstract
A 4-week study was conducted to determine the effect of starvation on activities and mRNA expression of lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) in hybrid tilapia (Oreochromis niloticus x O. areus). The tissue samples were sampled once a week. Results showed that body weight (BW) and hepatosomatic index (HSI) were decreased significantly (P < 0.05) during starvation. The percentages of crude fat and crude protein in the whole body and the fat content in muscle decreased significantly (P < 0.05), while the rate of moisture and crude ash increased significantly (P < 0.05). The response of LPL, HSL activities and mRNA expression in tissues was tissue dependent. The activities of LPL and HSL in muscle at day 7 were elevated by 2.5 times (P < 0.05) and 11.8 times (P < 0.05) of the value at day 0, respectively, and both then decreased to pre-starvation levels at day 14 and finally stabilized at a certain level afterward. LPL and HSL mRNA abundance in muscle remained relatively stable between 0 and 14 day; then, a significant increase was seen after 14 days. In the liver, LPL activity maintained a significantly increasing trend during starvation, while HSL activity rose dramatically at day 7 of starvation by 2.35 times (P < 0.05) and finally stabilized at a certain level. The mRNA abundance of liver LPL increased significantly during the whole process of starvation (P < 0.05), whereas the mRNA abundance of liver HSL decreased significantly at day 7 of starvation, elevating significantly afterward (P < 0.05).
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Affiliation(s)
- Chunyan Han
- College of Animal Science, South China Agricultural University, Guangzhou, China
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23
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Singh S, Dhingra S, Ramdath DD, Vasdev S, Gill V, Singal PK. Risk Factors Preceding Type 2 Diabetes and Cardiomyopathy. J Cardiovasc Transl Res 2010; 3:580-96. [DOI: 10.1007/s12265-010-9197-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 05/26/2010] [Indexed: 12/20/2022]
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Role of cellular bioenergetics in smooth muscle cell proliferation induced by platelet-derived growth factor. Biochem J 2010; 428:255-67. [PMID: 20331438 DOI: 10.1042/bj20100090] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Abnormal smooth muscle cell proliferation is a hallmark of vascular disease. Although growth factors are known to contribute to cell hyperplasia, the changes in metabolism associated with this response, particularly mitochondrial respiration, remain unclear. Given the increased energy requirements for proliferation, we hypothesized that PDGF (platelet-derived growth factor) would stimulate glycolysis and mitochondrial respiration and that this elevated bioenergetic capacity is required for smooth muscle cell hyperplasia. To test this hypothesis, cell proliferation, glycolytic flux and mitochondrial oxygen consumption were measured after treatment of primary rat aortic VSMCs (vascular smooth muscle cells) with PDGF. PDGF increased basal and maximal rates of glycolytic flux and mitochondrial oxygen consumption; enhancement of these bioenergetic pathways led to a substantial increase in the mitochondrial reserve capacity. Interventions with the PI3K (phosphoinositide 3-kinase) inhibitor LY-294002 or the glycolysis inhibitor 2-deoxy-D-glucose abrogated PDGF-stimulated proliferation and prevented augmentation of glycolysis and mitochondrial reserve capacity. Similarly, when L-glucose was substituted for D-glucose, PDGF-dependent proliferation was abolished, as were changes in glycolysis and mitochondrial respiration. Interestingly, LDH (lactate dehydrogenase) protein levels and activity were significantly increased after PDGF treatment. Moreover, substitution of L-lactate for D-glucose was sufficient to increase mitochondrial reserve capacity and cell proliferation after treatment with PDGF; these effects were inhibited by the LDH inhibitor oxamate. These results suggest that glycolysis, by providing substrates that enhance the mitochondrial reserve capacity, plays an essential role in PDGF-induced cell proliferation, underscoring the integrated metabolic response required for proliferation of VSMCs in the diseased vasculature.
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25
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Liddell JR, Zwingmann C, Schmidt MM, Thiessen A, Leibfritz D, Robinson SR, Dringen R. Sustained hydrogen peroxide stress decreases lactate production by cultured astrocytes. J Neurosci Res 2010; 87:2696-708. [PMID: 19382228 DOI: 10.1002/jnr.22093] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Oxidative stress and disrupted energy metabolism are common to many pathological conditions of the brain. Because astrocytes play an important role in the glucose metabolism of the brain, we have investigated whether sustained oxidative stress affects astroglial glucose metabolism with cultured primary rat astrocytes as a model system. Cultured astrocytes were exposed to a sustained concentration of approximately 50 muM H(2)O(2) in the presence of [U-(13)C]glucose, and cellular and extracellular contents of lactate and glucose were analysed by enzymatic assays and NMR spectroscopy. Exposure of the cells to sustained H(2)O(2) stress for up to 120 min significantly lowered the rate of lactate accumulation in the media to 61% +/- 14% of that in cultures incubated without peroxide. In addition, the ratio of lactate release to glucose consumption was lowered in peroxide-treated astrocytes to 77% +/- 13% of that in control cells, and the specific activity of glyceraldehyde-3-phosphate dehydrogenase had declined to about 10% of control cells within 90 min. In addition, the (13)C enrichment of intracellular and extracellular [(13)C]lactate was about 30% and 95%, respectively, and was not affected by the presence of peroxide, demonstrating that two metabolic pools of lactate are present in cultured astrocytes. The decreased rate of lactate production by astrocytes that have been exposed to peroxide stress is a new example of an alteration by oxidative stress of an important metabolic pathway in astrocytes. Such alterations could contribute to the pathological conditions that have been connected with oxidative stress and disrupted energy metabolism in the brain.
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Affiliation(s)
- Jeff R Liddell
- School of Psychology, Psychiatry, and Psychological Medicine, Monash University, Clayton, Victoria, Australia
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26
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Grüning NM, Lehrach H, Ralser M. Regulatory crosstalk of the metabolic network. Trends Biochem Sci 2010; 35:220-7. [PMID: 20060301 DOI: 10.1016/j.tibs.2009.12.001] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Revised: 11/23/2009] [Accepted: 12/03/2009] [Indexed: 02/04/2023]
Abstract
The metabolic network has a modular architecture, is robust to perturbations, and responds to biological stimuli and environmental conditions. Through monitoring by metabolite responsive macromolecules, metabolic pathways interact with the transcriptome and proteome. Whereas pathway interconnecting cofactors and substrates report on the overall state of the network, specialised intermediates measure the activity of individual functional units. Transitions in the network affect many of these regulatory metabolites, facilitating the parallel regulation of the timing and control of diverse biological processes. The metabolic network controls its own balance, chromatin structure and the biosynthesis of molecular cofactors; moreover, metabolic shifts are crucial in the response to oxidative stress and play a regulatory role in cancer.
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Affiliation(s)
- Nana-Maria Grüning
- Max Planck Institute for Molecular Genetics, Ihnestrasse 73, 14195 Berlin, Germany
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27
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Metabolic reconfiguration precedes transcriptional regulation in the antioxidant response. Nat Biotechnol 2009; 27:604-5. [PMID: 19587661 DOI: 10.1038/nbt0709-604] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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28
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A Model of NEFA Dynamics with Focus on the Postprandial State. Ann Biomed Eng 2009; 37:1897-909. [DOI: 10.1007/s10439-009-9738-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Accepted: 06/04/2009] [Indexed: 11/29/2022]
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29
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KARJA NIWAYANKURNIANI, FAHRUDIN MOKHAMAD, KIKUCHI KAZUHIRO. Inhibitory Effect of Iodoacetate on Developmental Competence of Porcine Early Stage Embryos In Vitro. HAYATI JOURNAL OF BIOSCIENCES 2009. [DOI: 10.4308/hjb.16.1.25] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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30
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Desai M, Guang Han, Ferelli M, Kallichanda N, Lane RH. Programmed upregulation of adipogenic transcription factors in intrauterine growth-restricted offspring. Reprod Sci 2009; 15:785-96. [PMID: 19017816 DOI: 10.1177/1933719108318597] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
As enhanced adipogenesis contributes to programmed obesity, adipogenic and lipogenic signaling pathways in intrauterine growth restricted (IUGR) offspring were examined. From 10 days to term gestation, rats received ad libitum food (control) or were 50% food-restricted (IUGR). Pups were nursed and weaned to ad libitum diet. mRNA and protein levels of adipogenic transcription factors and lipid enzymes (1 day and 9 month) and adipocyte cell size (3 weeks and 9 months) were determined. One day-old IUGR males showed upregulation of peroxisome proliferator-activated receptor (PPAR gamma(2)), including upstream factors regulating PPAR gamma, and RXR alpha, with which PPAR gamma heterodimerizes. Intracellular lipolytic enzyme (hormone-sensitive lipase) was downregulated. Nine-month-old IUGR males showed upregulation of adipogenic and lipogenic (SREBP1c) transcription factors with upregulation of enzymes facilitating fatty acid uptake (lipoprotein lipase) and synthesis (fatty acid synthase), leading to hypertrophic adipocytes. Paradoxical upregulation of adipogenesis signaling cascade prior to the development of obesity in IUGR males suggests early changes in signaling mechanisms.
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Affiliation(s)
- Mina Desai
- Perinatal Research Laboratories, Department of Obstetrics and Gynecology, David-Geffen School of Medicine at University of California, Los Angeles, CA 90502, USA.
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31
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Wamelink MMC, Struys EA, Jakobs C. The biochemistry, metabolism and inherited defects of the pentose phosphate pathway: a review. J Inherit Metab Dis 2008; 31:703-17. [PMID: 18987987 DOI: 10.1007/s10545-008-1015-6] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2008] [Revised: 09/09/2008] [Accepted: 09/17/2008] [Indexed: 11/27/2022]
Abstract
The recent discovery of two defects (ribose-5-phosphate isomerase deficiency and transaldolase deficiency) in the reversible part of the pentose phosphate pathway (PPP) has stimulated interest in this pathway. In this review we describe the functions of the PPP, its relation to other pathways of carbohydrate metabolism and an overview of the metabolic defects in the reversible part of the PPP.
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Affiliation(s)
- M M C Wamelink
- Metabolic Unit, Department of Clinical Chemistry, VU University Medical Center, De Boelelaan 1117, 1081 HV, Amsterdam, The Netherlands.
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32
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Ralser M, Benjamin IJ. Reductive stress on life span extension in C. elegans. BMC Res Notes 2008; 1:19. [PMID: 18710529 PMCID: PMC2518267 DOI: 10.1186/1756-0500-1-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Accepted: 06/04/2008] [Indexed: 11/13/2022] Open
Abstract
Recently, Schulz and colleagues have contributed to the ongoing controversy on the unproven role of oxidative stress in the aging process in their well-performed study 'Glucose restriction extends Caenorhabditis elegans life span by inducing mitochondrial respiration and increasing oxidative stress' (Cell Metab 2007, 6: 280–293). Here, we suggest an alternative hypothesis that reductive stress can prevent calorie-restriction induced life span extension. We draw attention to this condition as an explanation for some contradictory observations including the deleterious effects from antioxidants.
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Affiliation(s)
- Markus Ralser
- Max Planck Institute for Molecular Genetics, Ihnestrasse 73, 14195 Berlin, Germany.
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Sequential changes in the expression of genes involved in lipid metabolism in adipose tissue and liver in response to fasting. Pflugers Arch 2008; 456:825-36. [PMID: 18493788 DOI: 10.1007/s00424-008-0461-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 12/27/2007] [Accepted: 01/16/2008] [Indexed: 12/28/2022]
Abstract
The aim of this study was to provide a sequential analysis of the expression patterns of key genes involved in lipid metabolism in white adipose tissue (WAT) and liver and their relationship with blood parameters in response to fasting. Adult male rats were studied under different feeding conditions: feeding state, after 4, 8, or 24 h fasting, and after 3 h refeeding after 8 h fasting. Blood parameters and the expression of genes involved in lipogenesis and lipolysis in WAT and liver were analyzed. mRNA levels of genes involved in lipogenesis in liver (SREBP1c, FAS, and GPAT) had already decreased after 4 h fasting, as well as those of PPARgamma in WAT, whereas the decrease in SREBP1c, FAS, GPAT, and GLUT4 mRNA levels in WAT was observed after 8 h. Concerning lipolytic and fatty-acid-oxidation-related genes, liver PPARalpha, FGF21, CPT1, and PDK4 mRNA levels increased after 8 h fasting and those of ACOX1 after 24 h, and in WAT, ATGL, and CPT1 mRNA levels were greater after 24 h. Three hours refeeding increased the expression levels of PPARgamma in WAT, SREBP1c in both liver and WAT, and GPAT in liver, and decreased the expression levels of PPARalpha, CPT1, and PDK4 in liver. These results give new insight into the different adaptive time course response to fasting in the expression of genes involved in lipid metabolism, thus pointing out the very rapid response of lipogenic genes, particularly in liver, and the later response of lipolytic genes, particularly in WAT.
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Ralser M, Wamelink MM, Kowald A, Gerisch B, Heeren G, Struys EA, Klipp E, Jakobs C, Breitenbach M, Lehrach H, Krobitsch S. Dynamic rerouting of the carbohydrate flux is key to counteracting oxidative stress. J Biol 2007; 6:10. [PMID: 18154684 PMCID: PMC2373902 DOI: 10.1186/jbiol61] [Citation(s) in RCA: 402] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Revised: 08/07/2007] [Accepted: 10/12/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Eukaryotic cells have evolved various response mechanisms to counteract the deleterious consequences of oxidative stress. Among these processes, metabolic alterations seem to play an important role. RESULTS We recently discovered that yeast cells with reduced activity of the key glycolytic enzyme triosephosphate isomerase exhibit an increased resistance to the thiol-oxidizing reagent diamide. Here we show that this phenotype is conserved in Caenorhabditis elegans and that the underlying mechanism is based on a redirection of the metabolic flux from glycolysis to the pentose phosphate pathway, altering the redox equilibrium of the cytoplasmic NADP(H) pool. Remarkably, another key glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), is known to be inactivated in response to various oxidant treatments, and we show that this provokes a similar redirection of the metabolic flux. CONCLUSION The naturally occurring inactivation of GAPDH functions as a metabolic switch for rerouting the carbohydrate flux to counteract oxidative stress. As a consequence, altering the homoeostasis of cytoplasmic metabolites is a fundamental mechanism for balancing the redox state of eukaryotic cells under stress conditions.
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Affiliation(s)
- Markus Ralser
- Max Planck Institute for Molecular Genetics, Ihnestrasse 73, 14195 Berlin, Germany.
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Abstract
Lipolysis of white adipose tissue triacylglycerol stores results in the liberation of glycerol and nonesterified fatty acids that are released into the vasculature for use by other organs as energy substrates. In response to changes in nutritional state, lipolysis rates are precisely regulated through hormonal and biochemical signals. These signals modulate the activity of lipolytic enzymes and accessory proteins, allowing for maximal responsiveness of adipose tissue to changes in energy requirements and availability. Recently, a number of novel adipocyte triacylglyceride lipases have been identified, including desnutrin/ATGL, greatly expanding our understanding of adipocyte lipolysis. We have also begun to better appreciate the role of a number of nonenzymatic proteins that are critical to triacylglyceride breakdown. This review provides an overview of key mediators of lipolysis and the regulation of this process by changes in nutritional status and nutrient intakes.
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Affiliation(s)
- Robin E Duncan
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720, USA
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Abstract
Intestinal monoacylglycerol (MG) metabolism is well known to involve its anabolic reesterification to triacylglycerol (TG). We recently provided evidence for enterocyte MG hydrolysis and demonstrated expression of the monoacylglycerol lipase (MGL) gene in human intestinal Caco-2 cells and rodent small intestinal mucosa. Despite the large quantities of MG derived from dietary TG, the regulation of MG metabolism in the intestine has not been previously explored. In the present studies, we examined the mRNA expression, protein expression, and activities of the two known MG-metabolizing enzymes, MGL and MGAT2, in C57BL/6 mouse small intestine, as well as liver and adipose tissues, during development and under nutritional modifications. Results demonstrate that MG metabolism undergoes tissue-specific changes during development. Marked induction of small intestinal MGAT2 protein expression and activity were found during suckling. Moreover, while substantial levels of MGL protein and activity were detected in adult intestine, its regulation during ontogeny was complex, suggesting post-transcriptional regulation of expression. In addition, during the suckling period MG hydrolytic activity is likely to derive from carboxyl ester lipase rather than MGL. In contrast to intestinal MGL, liver MGL mRNA, protein and activity all increased 5-10-fold during development, suggesting that transcriptional regulation is the primary mechanism for hepatic MGL expression. Three weeks of high fat feeding (40% kcal) significantly induced MGL expression and activity in small intestine relative to low fat feeding (10% kcal), but little change was observed upon starvation, suggesting a role for MGL in dietary lipid assimilation following a high fat intake.
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Affiliation(s)
- Su-Hyoun Chon
- Department of Nutritional Sciences and the Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey 08901
| | - Yin Xiu Zhou
- Department of Nutritional Sciences and the Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey 08901
| | - Joseph L Dixon
- Department of Nutritional Sciences and the Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey 08901
| | - Judith Storch
- Department of Nutritional Sciences and the Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey 08901.
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León H, Bautista-López N, Sawicka J, Schulz R. Hydrogen peroxide causes cardiac dysfunction independent from its effects on matrix metalloproteinase-2 activation. Can J Physiol Pharmacol 2007; 85:341-8. [PMID: 17612643 DOI: 10.1139/y07-003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hydrogen peroxide (H2O2) causes cardiac dysfunction through multiple mechanisms. As oxidative stress can activate matrix metalloproteinases (MMPs) and, in particular, MMP-2 activity is associated with oxidative stress injury in the heart, we hypothesized that MMP-2 activation by H2O2 in isolated rat hearts contributes to cardiac dysfunction in this model. Isolated working rat hearts were perfused at 37 degrees C with a recirculating Krebs-Henseleit buffer+/-5 mmol/L pyruvate, known to protect hearts from oxidative stress. H2O2 (300 micromol/L) was added as a single bolus after 20 min of equilibration, and cardiac function was monitored for 60 min. MMPs activities in both the heart and perfusate samples were assessed by gelatin zymography. Tissue high energy phosphates were analysed by HPLC. The actions of 2 MMP inhibitors, doxycycline (75 micromol/L) or Ro 31-9790 (3 micromol/L), were also assessed. H2O2 at 300 micromol/L produced a rapid decline in cardiac mechanical function, which was maximal at 5 min. A peak in perfusate MMP-2 activity was also observed at 5 min. The deleterious effect of H2O2 on cardiac function was abolished by pyruvate but not by the MMPs inhibitors. This study suggests that in intact hearts, H2O2 induces contractile dysfunction independent of MMPs activation.
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Affiliation(s)
- Hernando León
- Department of Pediatrics, Cardiovascular Research Group, 4-62 Heritage Medical Research Centre, University of Alberta, Edmonton, AB T6G 2S2, Canada
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Verrax J, Vanbever S, Stockis J, Taper H, Calderon PB. Role of glycolysis inhibition and poly(ADP-ribose) polymerase activation in necrotic-like cell death caused by ascorbate/menadione-induced oxidative stress in K562 human chronic myelogenous leukemic cells. Int J Cancer 2007; 120:1192-7. [PMID: 17163414 DOI: 10.1002/ijc.22439] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Among different features of cancer cells, two of them have retained our interest: their nearly universal glycolytic phenotype and their sensitivity towards an oxidative stress. Therefore, we took advantage of these features to develop an experimental approach by selectively exposing cancer cells to an oxidant insult induced by the combination of menadione (vitamin K(3)) and ascorbate (vitamin C). Ascorbate enhances the menadione redox cycling, increases the formation of reactive oxygen species and kills K562 cells as shown by more than 65% of LDH leakage after 24 hr of incubation. Since both lactate formation and ATP content are depressed by about 80% following ascorbate/menadione exposure, we suggest that the major intracellular event involved in such a cytotoxicity is related to the impairment of glycolysis. Indeed, NAD(+) is rapidly and severely depleted, a fact most probably related to a strong Poly(ADP-ribose) polymerase (PARP) activation, as shown by the high amount of poly-ADP-ribosylated proteins. The addition of N-acetylcysteine (NAC) restores most of the ATP content and the production of lactate as well. The PARP inhibitor dihydroxyisoquinoline (DiQ) was able to partially restore both parameters as well as cell death induced by ascorbate/menadione. These results suggest that the PARP activation induced by the oxidative stress is a major but not the only intracellular event involved in cell death by ascorbate/menadione. Due to the high energetic dependence of cancer cells on glycolysis, the impairment of such an essential pathway may explain the effectiveness of this combination to kill cancer cells.
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Affiliation(s)
- Julien Verrax
- Unité de Pharmacocinétique, Métabolisme, Nutrition et Toxicologie, Département des sciences pharmaceutiques, Université Catholique de Louvain, Belgium
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Wang BS, Chang LW, Yen WJ, Duh PD. Antioxidative effect of sesame coat on LDL oxidation and oxidative stress in macrophages. Food Chem 2007. [DOI: 10.1016/j.foodchem.2006.05.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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40
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Manju L, Nair RR. Magnesium deficiency augments myocardial response to reactive oxygen species. Can J Physiol Pharmacol 2006; 84:617-24. [PMID: 16900246 DOI: 10.1139/y06-017] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Magnesium (Mg) deficiency and oxidative stress are independently implicated in the etiopathogenesis of various cardiovascular disorders. This study was undertaken to examine the hypothesis that Mg deficiency augments the myocardial response to oxidative stress. Electrically stimulated rat papillary muscle was used for recording the contractile variation. Biochemical variables of energy metabolism (adenosine triphosphate (ATP) and creatine phosphate) and markers of tissue injury (lactate dehydrogenase (LDH) release and lipidperoxidation), which can affect myocardial contractility, were assayed in Langendorff-perfused rat hearts. Hydrogen peroxide (100 micromol/L) was used as the source of reactive oxygen species. The negative inotropic response to H2O2 was significantly higher in Mg deficiency (0.48 mmol Mg/L) than in Mg sufficiency (1.2 mmol Mg/L). Low Mg levels did not affect ATP levels or tissue lipid peroxidation. However, H2O2 induced a decrease in ATP; enhanced lipid peroxidation and the release of LDH were augmented by Mg deficiency. Increased lipid peroxidation associated with a decrease in available energy might be responsible for the augmentation of the negative inotropic response to H2O2 in Mg deficiency. The observations from this study validate the hypothesis that myocardial response to oxidative stress is augmented by Mg deficiency. This observation has significance in ischemia-reperfusion injury, where Mg deficiency can have an additive effect on the debilitating consequences.
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Affiliation(s)
- L Manju
- Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram 695 011, India
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41
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Knott EM, Sun J, Lei Y, Ryou MG, Olivencia-Yurvati AH, Mallet RT. Pyruvate mitigates oxidative stress during reperfusion of cardioplegia-arrested myocardium. Ann Thorac Surg 2006; 81:928-34. [PMID: 16488697 DOI: 10.1016/j.athoracsur.2005.08.046] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 08/24/2005] [Accepted: 08/25/2005] [Indexed: 12/30/2022]
Abstract
BACKGROUND Cardioplegic arrest and reperfusion of the myocardium imposes oxidative stress that could potentially inactivate metabolic enzymes and compromise energy production. This study determined the impact of cardioplegic arrest and reperfusion on activities of several oxidant-sensitive enzymes, and tested whether pyruvate, a natural metabolic fuel and antioxidant, mitigates oxidant stress, protects enzymes, and bolsters myocardial energy state after reperfusion. METHODS In situ swine hearts were arrested for 60 minutes with 4:1 blood:crystalloid cardioplegia, and then reperfused for 3 minutes with cardioplegia-free blood with or without approximately 12 mM pyruvate. Tissue metabolites and enzyme activities were measured in left ventricular myocardium snap frozen at 45 minutes of arrest and 3 minutes of reperfusion. RESULTS The 8-isoprostane content, a measure of lipid peroxidation, sharply increased upon reperfusion, coincident with a 70% decline in redox state of the intracellular antioxidant glutathione. Aconitase and glucose 6-phosphate dehydrogenase activities fell during arrest; creatine kinase and phosphofructokinase were inactivated upon reperfusion. Pyruvate suppressed 8-isoprostane formation, maintained glutathione redox state, and enhanced phosphocreatine phosphorylation potential, a measure of myocardial energy state, during reperfusion. Pyruvate reactivated creatine kinase and aconitase, which are at least partially mitochondrial enzymes, but did not protect the cytosolic enzymes glucose 6-phosphate dehydrogenase and phosphofructokinase. CONCLUSIONS Administration of pyruvate upon reperfusion after cardioplegic arrest mitigates oxidative stress, protects mitochondrial enzymes and increases myocardial energy state. These results support therapeutic application of pyruvate-enhanced reperfusion to prevent cardiac injury after cardioplegic arrest.
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Affiliation(s)
- E Marty Knott
- Department of Integrative Physiology, University of North Texas Health Science Center, Fort Worth, Texas 76107-2699, USA
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42
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Cecarini V, Gee J, Fioretti E, Amici M, Angeletti M, Eleuteri AM, Keller JN. Protein oxidation and cellular homeostasis: Emphasis on metabolism. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1773:93-104. [PMID: 17023064 DOI: 10.1016/j.bbamcr.2006.08.039] [Citation(s) in RCA: 167] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2006] [Revised: 08/22/2006] [Accepted: 08/23/2006] [Indexed: 12/31/2022]
Abstract
Reactive oxygen species (ROS) are generated as the result of a number of physiological and pathological processes. Once formed ROS can promote multiple forms of oxidative damage, including protein oxidation, and thereby influence the function of a diverse array of cellular processes. This review summarizes the mechanisms by which ROS are generated in a variety of cell types, outlines the mechanisms which control the levels of ROS, and describes specific proteins which are common targets of ROS. Additionally, this review outlines cellular processes which can degrade or repair oxidized proteins, and ultimately describes the potential outcomes of protein oxidation on cellular homeostasis. In particular, this review focuses on the relationship between elevations in protein oxidation and multiple aspects of cellular metabolism. Together, this review describes a potential role for elevated levels of protein oxidation contributing to cellular dysfunction and oxidative stress via impacts on cellular metabolism.
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Affiliation(s)
- Valentina Cecarini
- Post Graduate School of Clinical Biochemistry, Departments of Molecular and Cellular and Animal Biology, University of Camerino, Camerino, Italy
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Tsujita T. Basal lipolysis in epididymal fat cells from streptozotocin-induced diabetic rats. J Nutr Sci Vitaminol (Tokyo) 2006; 52:47-53. [PMID: 16637229 DOI: 10.3177/jnsv.52.47] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The level of free fatty acid (FFA) in plasma is increased by diabetes. The increase in plasma FFA levels accompanied the stimulation of basal lipolysis (i.e. lipolysis in the absence of lipolytic agents) in fat cells. Injection of streptozotocin with rats resulted in a significant increase in basal FFA production (5.5 fold) in fat cells. However, basal glycerol production in fat cells was increased only 1.5 fold by streptozotocin-induced diabetes, implying that FFA re-esterification in fat cells was decreased by streptozotocin-induced diabetes. The FFA re-esterification in fat cells was also decreased by 1 d of fasting. Although basal lipolysis was increased by streptozotocin-induced diabetes or 1-d fasting, neutral triacylglycerol lipase activity and the immunoreactive HSL protein content in fat cells from streptozotocin-induced diabetic rats or 1-d fasting rats were not significantly changed. Although beta-blockers inhibited lipolysis induced by norepinephrine at a concentration of 10(-4) M, it failed to inhibit the basal lipolysis and FFA re-esterification in fat cells from streptozotocin-induced diabetic rats. Nor did insulin or H-89, another antilipolytic agent, affect basal lipolysis or FFA re-esterification in fat cells from streptozotocin-induced diabetic rats. These results indicate that basal FFA production may be induced by a decrease of re-esterification of FFA in diabetic rats and is not affected by antilipolytic agents such as insulin, beta-blockers or H-89.
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Affiliation(s)
- Takahiro Tsujita
- Division of Medical Bioscience, Department of Bioscience, Integrated Center for Sciences, Ehime University, Toon, Japan.
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Durot I, Devillard L, Tissier C, Vandroux D, Voisin S, Jaquir S, Rochette L, Athias P. Dependence on the phospholipid polyunsaturated fatty acids of the oxidative injury of isolated cardiomyocytes. Free Radic Res 2006; 40:251-61. [PMID: 16484041 DOI: 10.1080/10715760500509165] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
We investigated the influence of PUFA in phospholipids (PL) on the functional characteristics of cultured cardiomyocytes (CM) in basal conditions and during free radical (FR) stress provoked either by the xanthine/xanthine oxidase (X/XO) system or by a (9Z, 11E, 13 (S), 15Z)-13-hydroperoxyoctadecatrienoic acid (13-HpOTrE). CM were grown in media containing either n - 3 (eicosapentaenoic acid, EPA, and docosahexaenoic acid, DHA) or n - 6 (arachidonic acid, AA). These two groups of CM displayed different PUFA n - 6/n - 3 ratio in PL. However, their basal electromechanical characteristics were similar. The X/XO system drastically altered CM functions, without difference between the two groups of CM. 13-HpOTrE caused a moderate and reversible depression in action potential parameters, which was dependent upon the PL PUFA, since the n - 3-enriched CM exhibited an earlier functional depression but faster recovery. Thus, the peroxidative damage of CM depended on a cross relationship between FR species and the PL PUFA composition.
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Affiliation(s)
- Isabelle Durot
- Laboratory of Cardiovascular Physiopathology and Pharmacology, Institute of Cardiovascular Research, University Hospital Center, 21079 Dijon, France
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Sheline CT, Wei L. Free radical-mediated neurotoxicity may be caused by inhibition of mitochondrial dehydrogenases in vitro and in vivo. Neuroscience 2006; 140:235-46. [PMID: 16563643 DOI: 10.1016/j.neuroscience.2006.02.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Revised: 02/03/2006] [Accepted: 02/08/2006] [Indexed: 11/28/2022]
Abstract
We previously demonstrated that copper facilitated the formation of reactive oxygen species, and inhibited pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase in vitro and in animal models of Wilson's disease in vivo. However, direct Cu(2+) toxicity has only been demonstrated for Wilson's disease. We now hypothesize that inhibition of these mitochondrial dehydrogenases might also contribute to many other injuries and disorders that are reactive oxygen species-mediated. We have modeled reactive oxygen species-mediated injuries using inducers of reactive oxygen species such as hydrogen peroxide, ethacrynic acid or menadione, or another redox active metal (Cd(2+)). Here we demonstrated that these toxic exposures were accompanied by an early marked reduction in both pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase activities, followed by a decrease in neuronal mitochondrial transmembrane potential and ATP, prior to murine cortical neuronal death. Thiamine (6 mM), and dihydrolipoic acid (50 microM), required cofactors for pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase (thiamine as thiamine pyrophosphate), attenuated the reactive oxygen species-induced reductions in these enzyme activities, as well as subsequent loss of mitochondrial transmembrane potential and ATP, and neuronal death. We next tested the effect of thiamine supplementation on an in vivo model of reactive oxygen species-mediated injury, transient middle cerebral artery occlusion, and reperfusion in rats. Oral or i.p. thiamine administration reduced the middle cerebral artery occlusion-induced infarct. These data suggest that reactive oxygen species-induced neuronal death may be caused in part by reactive oxygen species-mediated inhibition of pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase in vitro and in vivo, and that thiamine or dihydrolipoic acid may constitute potential therapeutic agents not just against Cu(2+) neurotoxicity, but may reduce neuronal degeneration in the broader range of diseases mediated by free radical stress.
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Affiliation(s)
- C T Sheline
- Department of Neurology and Center for the Study of Nervous System Injury, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.
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Ahn IS, Do MS, Kim SO, Jung HS, Kim YI, Kim HJ, Park KY. Antiobesity Effect ofKochujang(Korean Fermented Red Pepper Paste) Extract in 3T3-L1 Adipocytes. J Med Food 2006; 9:15-21. [PMID: 16579723 DOI: 10.1089/jmf.2006.9.15] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Kochujang (Korean fermented red pepper paste) is a mixture of fermented soybeans, wheat, and red pepper powder. Kochujang has been reported to reduce body fat gain and lipid levels of adipose tissues and serum in rats. We studied the inhibitory effect of Kochujang on lipid accumulation and investigated the molecular mechanism of the action in 3T3-L1 adipocytes by measuring the expression levels of adipocyte-specific genes by real-time reverse transcription-polymerase chain reaction. When 3T3-L1 adipocytes were treated with Kochujang extract (KE), the sizes of adipocytes and leptin secretion were decreased. Hormone-sensitive lipase (HSL) was transcriptionally up-regulated at 4 hours, and glycerol secretion was increased at both 4 hours and 24 hours. Moreover, mRNA expression levels of both sterol regulatory element-binding protein 1-c (SREBP-1c) and peroxisome proliferator-activated receptor-gamma (PPAR-gamma), which are critical transcription factors for adipogenesis, were markedly down-regulated. Tumor necrosis factor-alpha (TNF-alpha) is reported to impair pre-adipocyte differentiation and induce lipolysis and apoptosis. KE treatment of 3T3-L1 adipocytes decreased TNF-alpha mRNA levels, but had no apparent affect on apoptosis. Taken together, our study shows that Kochujang decreased lipid accumulation in 3T3-L1 adipocytes by inhibiting adipogenesis through down-regulation of SREBP-1c and PPAR-gamma and by stimulation of lipolysis due to increased HSL activity. TNF-alpha might not be involved in the reduction of lipid accumulation by KE.
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Affiliation(s)
- In-Sook Ahn
- Department of Food Science and Nutrition, Pusan National University, Busan, Korea
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Taylor-McCabe KJ, Wang Z, Sauer NN, Marrone BL. Proteomic analysis of beryllium-induced genotoxicity in anEscherichia coli mutant model system. Proteomics 2006; 6:1663-75. [PMID: 16447159 DOI: 10.1002/pmic.200500190] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Beryllium is the second lightest metal, has a high melting point and high strength-to-weight ratio, and is chemically stable. These unique chemical characteristics make beryllium metal an ideal choice as a component material for a wide variety of applications in aerospace, defense, nuclear weapons, and industry. However, inhalation of beryllium dust or fumes induces significant health effects, including chronic beryllium disease and lung cancer. In this study, the mutagenicity of beryllium sulfate (BeSO(4)) and the comutagenicity of beryllium with a known mutagen 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) were evaluated using a forward mutant detection system developed in Escherichia coli. In this system, BeSO(4) was shown to be weakly mutagenic alone and significantly enhanced the mutagenicity of MNNG up to 3.5-fold over MNNG alone. Based on these results a proteomic study was conducted to identify the proteins regulated by BeSO(4). Using the techniques of 2-DE and oMALDI-TOF MS, we successfully identified 32 proteins being differentially regulated by beryllium and/or MNNG in the E. coli test system. This is the first study to describe the proteins regulated by beryllium in vitro, and the results suggest several potential pathways for the focus of further research into the mechanisms underlying beryllium-induced genotoxicity.
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Lee SH, Yoon DW, Jung JY, Lee KJ, Kim SJ, Lee EJ, Kang EH, Jung KH, Lee SY, Lee SY, Kim JH, Shin C, Shim JJ, In KH, Yoo SH, Kang KH. The Effects of Ethyl Pyruvate on Lipopolysaccharide-induced Acute Lung Injury. Tuberc Respir Dis (Seoul) 2006. [DOI: 10.4046/trd.2006.61.4.374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Affiliation(s)
- Seung Hyeun Lee
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Dae Wui Yoon
- Institute of Human Genomic Study, Ansan Hospital, Korea University Medical Center, Ansan, Korea
| | - Jin Yong Jung
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Kyung Joo Lee
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Se Joong Kim
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Eun Joo Lee
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Eun Hae Kang
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Ki Hwan Jung
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Sung Yong Lee
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Sang Yeub Lee
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Je Hyeong Kim
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Chol Shin
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Jae Jeong Shim
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Kwang Ho In
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Se Hwa Yoo
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
| | - Kyung Ho Kang
- Department of Internal Medicine, College of Medicine, Korea University, Seoul, Korea
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Riley JK, Carayannopoulos MO, Wyman AH, Chi M, Moley KH. Phosphatidylinositol 3-kinase activity is critical for glucose metabolism and embryo survival in murine blastocysts. J Biol Chem 2005; 281:6010-9. [PMID: 16272157 DOI: 10.1074/jbc.m506982200] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The phosphatidylinositol 3-kinase (PI3K) signal transduction pathway is a well known mediator of cell growth, proliferation, and survival signals. Whereas the expression and function of this pathway has been documented during mammalian development, evidence demonstrating the physiologic importance of this pathway in murine preimplantation embryos is beginning to emerge. This study demonstrates that inhibition of the PI3K pathway leads to the induction of apoptosis in both murine blastocysts and trophoblast stem cells. The apoptosis induced in both model systems correlates with a decrease in the expression of the glucose transporter GLUT1 at the plasma membrane. In addition, blastocysts cultured in the presence of the PI3K inhibitor LY-294002 display a decrease in both 2-deoxyglucose uptake and hexokinase activity as compared with control blastocysts. To determine the impact of PI3K inhibition on pregnancy outcome, embryo transfer experiments were performed. Blastocysts cultured in the presence of LY-294002 demonstrate a dramatic increase in fetal resorptions as compared with control embryos. Finally, we demonstrate that impairment of glucose metabolism via iodoacetate, a glyceraldehyde-3-phosphate dehydrogenase inhibitor, is sufficient to induce apoptosis in both blastocysts and trophoblast stem cells. Moreover, blastocysts treated with iodoacetate result in poor pregnancy outcome as determined by embryo transfer experiments. Taken together these data demonstrate the critical importance of the PI3K pathway in preimplantation embryo survival and pregnancy outcome and further emphasize the importance of glucose utilization and metabolism in cell survival pathways.
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Affiliation(s)
- Joan K Riley
- Department of Obstetrics and Gynecology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Mallet RT, Sun J, Knott EM, Sharma AB, Olivencia-Yurvati AH. Metabolic cardioprotection by pyruvate: recent progress. Exp Biol Med (Maywood) 2005; 230:435-43. [PMID: 15985618 DOI: 10.1177/153537020523000701] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Pyruvate, a natural metabolic fuel and antioxidant in myocardium and other tissues, exerts a variety of cardioprotective actions when provided at supraphysiological concentrations. Pyruvate increases cardiac contractile performance and myocardial energy state, bolsters endogenous antioxidant systems, and protects myocardium from ischemia-reperfusion injury and oxidant stress. This article reviews and discusses basic and clinically oriented research conducted over the last several years that has yielded fundamental information on pyruvate's inotropic and cardioprotective mechanisms. Particular attention is placed on pyruvate's enhancement of sarcoplasmic reticular Ca2+ transport, its antioxidant properties, and its ability to mitigate reversible and irreversible myocardial injury. These research efforts are establishing the essential foundation for clinical application of pyruvate therapy in numerous settings including cardiopulmonary bypass surgery, cardiopulmonary resuscitation, myocardial stunning, and cardiac failure.
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Affiliation(s)
- Robert T Mallet
- Department of Integrative Physiology, University of North Texas Health Science Center, 3500 Camp Bowie Boulevard, Fort Worth, TX 76107-2699, USA.
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