1
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Petrovskaya AV, Tverskoi AM, Barykin EP, Varshavskaya KB, Dalina AA, Mitkevich VA, Makarov AA, Petrushanko IY. Distinct Effects of Beta-Amyloid, Its Isomerized and Phosphorylated Forms on the Redox Status and Mitochondrial Functioning of the Blood-Brain Barrier Endothelium. Int J Mol Sci 2022; 24:ijms24010183. [PMID: 36613623 PMCID: PMC9820675 DOI: 10.3390/ijms24010183] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/14/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
The Alzheimer's disease (AD)-associated breakdown of the blood-brain barrier (BBB) promotes the accumulation of beta-amyloid peptide (Aβ) in the brain as the BBB cells provide Aβ transport from the brain parenchyma to the blood, and vice versa. The breakdown of the BBB during AD may be caused by the emergence of blood-borne Aβ pathogenic forms, such as structurally and chemically modified Aβ species; their effect on the BBB cells has not yet been studied. Here, we report that the effects of Aβ42, Aβ42, containing isomerized Asp7 residue (iso-Aβ42) or phosphorylated Ser8 residue (p-Aβ42) on the mitochondrial potential and respiration are closely related to the redox status changes in the mouse brain endothelial cells bEnd.3. Aβ42 and iso-Aβ42 cause a significant increase in nitric oxide, reactive oxygen species, glutathione, cytosolic calcium and the mitochondrial potential after 4 h of incubation. P-Aβ42 either does not affect or its effect develops after 24 h of incubation. Aβ42 and iso-Aβ42 activate mitochondrial respiration compared to p-Aβ42. The isomerized form promotes a greater cytotoxicity and mitochondrial dysfunction, causing maximum oxidative stress. Thus, Aβ42, p-Aβ42 and iso-Aβ42 isoforms differently affect the BBBs' cell redox parameters, significantly modulating the functioning of the mitochondria. The changes in the level of modified Aβ forms can contribute to the BBBs' breakdown during AD.
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Geraets IME, Coumans WA, Strzelecka A, Schönleitner P, Antoons G, Schianchi F, Willemars MMA, Kapsokalyvas D, Glatz JFC, Luiken JJFP, Nabben M. Metabolic Interventions to Prevent Hypertrophy-Induced Alterations in Contractile Properties In Vitro. Int J Mol Sci 2021; 22:ijms22073620. [PMID: 33807195 PMCID: PMC8037191 DOI: 10.3390/ijms22073620] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 12/13/2022] Open
Abstract
(1) Background: The exact mechanism(s) underlying pathological changes in a heart in transition to hypertrophy and failure are not yet fully understood. However, alterations in cardiac energy metabolism seem to be an important contributor. We characterized an in vitro model of adrenergic stimulation-induced cardiac hypertrophy for studying metabolic, structural, and functional changes over time. Accordingly, we investigated whether metabolic interventions prevent cardiac structural and functional changes; (2) Methods: Primary rat cardiomyocytes were treated with phenylephrine (PE) for 16 h, 24 h, or 48 h, whereafter hypertrophic marker expression, protein synthesis rate, glucose uptake, and contractile function were assessed; (3) Results: 24 h PE treatment increased expression of hypertrophic markers, phosphorylation of hypertrophy-related signaling kinases, protein synthesis, and glucose uptake. Importantly, the increased glucose uptake preceded structural and functional changes, suggesting a causal role for metabolism in the onset of PE-induced hypertrophy. Indeed, PE treatment in the presence of a PAN-Akt inhibitor or of a GLUT4 inhibitor dipyridamole prevented PE-induced increases in cellular glucose uptake and ameliorated PE-induced contractile alterations; (4) Conclusions: Pharmacological interventions, forcing substrate metabolism away from glucose utilization, improved contractile properties in PE-treated cardiomyocytes, suggesting that targeting glucose uptake, independent from protein synthesis, forms a promising strategy to prevent hypertrophy and hypertrophy-induced cardiac dysfunction.
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Affiliation(s)
- Ilvy M. E. Geraets
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (I.M.E.G.); (W.A.C.); (A.S.); (F.S.); (M.M.A.W.); (D.K.); (J.F.C.G.); (J.J.F.P.L.)
| | - Will A. Coumans
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (I.M.E.G.); (W.A.C.); (A.S.); (F.S.); (M.M.A.W.); (D.K.); (J.F.C.G.); (J.J.F.P.L.)
| | - Agnieszka Strzelecka
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (I.M.E.G.); (W.A.C.); (A.S.); (F.S.); (M.M.A.W.); (D.K.); (J.F.C.G.); (J.J.F.P.L.)
| | - Patrick Schönleitner
- Departments of Physiology, Maastricht University, 6200-MD Maastricht, The Netherlands; (P.S.); (G.A.)
- CARIM School for Cardiovascular Diseases, Maastricht University, 6200-MD Maastricht, The Netherlands
| | - Gudrun Antoons
- Departments of Physiology, Maastricht University, 6200-MD Maastricht, The Netherlands; (P.S.); (G.A.)
- CARIM School for Cardiovascular Diseases, Maastricht University, 6200-MD Maastricht, The Netherlands
| | - Francesco Schianchi
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (I.M.E.G.); (W.A.C.); (A.S.); (F.S.); (M.M.A.W.); (D.K.); (J.F.C.G.); (J.J.F.P.L.)
| | - Myrthe M. A. Willemars
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (I.M.E.G.); (W.A.C.); (A.S.); (F.S.); (M.M.A.W.); (D.K.); (J.F.C.G.); (J.J.F.P.L.)
| | - Dimitrios Kapsokalyvas
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (I.M.E.G.); (W.A.C.); (A.S.); (F.S.); (M.M.A.W.); (D.K.); (J.F.C.G.); (J.J.F.P.L.)
| | - Jan F. C. Glatz
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (I.M.E.G.); (W.A.C.); (A.S.); (F.S.); (M.M.A.W.); (D.K.); (J.F.C.G.); (J.J.F.P.L.)
- CARIM School for Cardiovascular Diseases, Maastricht University, 6200-MD Maastricht, The Netherlands
| | - Joost J. F. P. Luiken
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (I.M.E.G.); (W.A.C.); (A.S.); (F.S.); (M.M.A.W.); (D.K.); (J.F.C.G.); (J.J.F.P.L.)
- Department of Clinical Genetics, Maastricht University Medical Center, 6200-MD Maastricht, The Netherlands
| | - Miranda Nabben
- Department of Genetics & Cell Biology, Faculty of Health, Medicine and Life Sciences, Maastricht University, 6200-MD Maastricht, The Netherlands; (I.M.E.G.); (W.A.C.); (A.S.); (F.S.); (M.M.A.W.); (D.K.); (J.F.C.G.); (J.J.F.P.L.)
- CARIM School for Cardiovascular Diseases, Maastricht University, 6200-MD Maastricht, The Netherlands
- Department of Clinical Genetics, Maastricht University Medical Center, 6200-MD Maastricht, The Netherlands
- Correspondence: ; Tel.: +31-43-3881998
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3
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Kuspriyanti NP, Ariyanto EF, Syamsunarno MRAA. Role of Warburg Effect in Cardiovascular Diseases: A Potential Treatment Option. Open Cardiovasc Med J 2021. [DOI: 10.2174/1874192402115010006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Background:
Under normal conditions, the heart obtains ATP through the oxidation of fatty acids, glucose, and ketones. While fatty acids are the main source of energy in the heart, under certain conditions, the main source of energy shifts to glucose where pyruvate converts into lactate, to meet the energy demand. The Warburg effect is the energy shift from oxidative phosphorylation to glycolysis in the presence of oxygen. This effect is observed in tumors as well as in diseases, including cardiovascular diseases. If glycolysis is more dominant than glucose oxidation, the two pathways uncouple, contributing to the severity of the heart condition. Recently, several studies have documented changes in metabolism in several cardiovascular diseases; however, the specific mechanisms remain unclear.
Methods:
This literature review was conducted by an electronic database of Pub Med, Google Scholar, and Scopus published until 2020. Relevant papers are selected based on inclusion and exclusion criteria.
Results:
A total of 162 potentially relevant articles after the title and abstract screening were screened for full-text. Finally, 135 papers were included for the review article.
Discussion:
This review discusses the effects of alterations in glucose metabolism, particularly the Warburg effect, on cardiovascular diseases, including heart failure, atrial fibrillation, and cardiac hypertrophy.
Conclusion:
Reversing the Warburg effect could become a potential treatment option for cardiovascular diseases.
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4
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PARIS-DJ-1 Interaction Regulates Mitochondrial Functions in Cardiomyocytes, Which Is Critically Important in Cardiac Hypertrophy. Mol Cell Biol 2020; 41:MCB.00106-20. [PMID: 33077496 DOI: 10.1128/mcb.00106-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 10/05/2020] [Indexed: 11/20/2022] Open
Abstract
Mitochondrial dysfunction is one of the major pathological attributes of cardiac hypertrophy and is associated with reduced expression of PGC1α in cardiomyocytes. However, the transcriptional regulation of PGC1α remains elusive. Here, we show that parkin interacting substrate (PARIS), a KRAB zinc finger protein, prevented PGC1α transcription despite the induction of cardiomyocytes with hypertrophic stimuli. Moreover, PARIS expression and its nuclear localization are enhanced in hypertrophy both in vitro and in vivo Knocking down PARIS resulted in mitochondrial biogenesis and improved respiration and other biochemical features that were compromised during hypertrophy. Furthermore, a PARIS-dependent proteome showed exclusive binding of a deSUMOylating protein called DJ-1 to PARIS in control cells, while this interaction is completely abrogated in hypertrophied cells. We further demonstrate that proteasomal degradation of DJ-1 under oxidative stress led to augmented PARIS SUMOylation and consequent repression of PGC1α promoter activity. SUMOylation-resistant mutants of PARIS failed to repress PGC1α, suggesting a critical role for PARIS SUMOylation in hypertrophy. The present study, therefore, proposes a novel regulatory pathway where DJ-1 acts as an oxidative stress sensor and contributes to the feedback loop governing PARIS-mediated mitochondrial function.
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5
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Lorkiewicz PK, Gibb AA, Rood BR, He L, Zheng Y, Clem BF, Zhang X, Hill BG. Integration of flux measurements and pharmacological controls to optimize stable isotope-resolved metabolomics workflows and interpretation. Sci Rep 2019; 9:13705. [PMID: 31548575 PMCID: PMC6757038 DOI: 10.1038/s41598-019-50183-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 09/02/2019] [Indexed: 11/29/2022] Open
Abstract
Stable isotope-resolved metabolomics (SIRM) provides information regarding the relative activity of numerous metabolic pathways and the contribution of nutrients to specific metabolite pools; however, SIRM experiments can be difficult to execute, and data interpretation is challenging. Furthermore, standardization of analytical procedures and workflows remain significant obstacles for widespread reproducibility. Here, we demonstrate the workflow of a typical SIRM experiment and suggest experimental controls and measures of cross-validation that improve data interpretation. Inhibitors of glycolysis and oxidative phosphorylation as well as mitochondrial uncouplers serve as pharmacological controls, which help define metabolic flux configurations that occur under well-controlled metabolic states. We demonstrate how such controls and time course labeling experiments improve confidence in metabolite assignments as well as delineate metabolic pathway relationships. Moreover, we demonstrate how radiolabeled tracers and extracellular flux analyses integrate with SIRM to improve data interpretation. Collectively, these results show how integration of flux methodologies and use of pharmacological controls increase confidence in SIRM data and provide new biological insights.
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Affiliation(s)
- Pawel K Lorkiewicz
- Department of Medicine, Division of Environmental Medicine, Christina Lee Brown Envirome Institute, Diabetes and Obesity Center, University of Louisville, Louisville, USA
- Department of Chemistry, Center for Regulatory and Environmental Analytical Metabolomics, University of Louisville, Louisville, USA
| | - Andrew A Gibb
- Department of Medicine, Division of Environmental Medicine, Christina Lee Brown Envirome Institute, Diabetes and Obesity Center, University of Louisville, Louisville, USA
- Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Benjamin R Rood
- Department of Medicine, Division of Environmental Medicine, Christina Lee Brown Envirome Institute, Diabetes and Obesity Center, University of Louisville, Louisville, USA
| | - Liqing He
- Department of Chemistry, Center for Regulatory and Environmental Analytical Metabolomics, University of Louisville, Louisville, USA
| | - Yuting Zheng
- Department of Medicine, Division of Environmental Medicine, Christina Lee Brown Envirome Institute, Diabetes and Obesity Center, University of Louisville, Louisville, USA
| | - Brian F Clem
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, KY, USA
| | - Xiang Zhang
- Department of Chemistry, Center for Regulatory and Environmental Analytical Metabolomics, University of Louisville, Louisville, USA
| | - Bradford G Hill
- Department of Medicine, Division of Environmental Medicine, Christina Lee Brown Envirome Institute, Diabetes and Obesity Center, University of Louisville, Louisville, USA.
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6
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Weng X, Zhang X, Lu X, Wu J, Li S. Reduced mitochondrial response sensitivity is involved in the anti‑apoptotic effect of dexmedetomidine pretreatment in cardiomyocytes. Int J Mol Med 2018; 41:2328-2338. [PMID: 29328437 DOI: 10.3892/ijmm.2018.3384] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Accepted: 01/10/2018] [Indexed: 11/05/2022] Open
Abstract
Dexmedetomidine is a commonly used α2-adreno-ceptor agonist, which affects various organs, including providing beneficial effects on the heart. However, the mechanism underlying the cardiac benefit remains to be fully elucidated. In the present study, it was demonstrated that dexmedetomidine pretreatment on primary cultured rat cardiomyocytes protected against reactive oxygen species (ROS)‑induced apoptosis. In terms of the potential mechanism, it was demonstrated that dexmedetomidine inhibited mitochondrial biogenesis and mitochondrial respiratory complexes, but with increased coupling efficiency. However, dexmedetomidine upregulated mitochondrial membrane potential (Δψm) and resisted against the loss of Δψm induced by carbonilcyanide p‑triflouromethoxyphenylhydrazone. Due to the importance of mitochondria affecting ROS, the present study investigated the dexmedetomidine‑suppressed mitochondrial response to H2O2 stimulation, which was explained by suppressed ROS levels and the suppression of the increased oxygen consumption rate. Results demonstrated for the first time, to the best of our knowledge, a novel protective mechanism for dexmedetomidine on cardiomyocytes through the attenuated response of mitochondria towards H2O2, which had a protective effect against ROS‑induced apoptosis.
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Affiliation(s)
- Xiaojian Weng
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, P.R. China
| | - Xiaodan Zhang
- Department of Intensive Care Unit, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, P.R. China
| | - Xiaofei Lu
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, P.R. China
| | - Jin Wu
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, P.R. China
| | - Shitong Li
- Department of Anesthesiology, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, P.R. China
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7
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Osuma EA, Riggs DW, Gibb AA, Hill BG. High throughput measurement of metabolism in planarians reveals activation of glycolysis during regeneration. ACTA ACUST UNITED AC 2018; 5:78-86. [PMID: 29721328 PMCID: PMC5911454 DOI: 10.1002/reg2.95] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 10/30/2017] [Accepted: 10/30/2017] [Indexed: 12/18/2022]
Abstract
Planarians are outstanding models for studying mechanisms of regeneration; however, there are few methods to measure changes in their metabolism. Examining metabolism in planarians is important because the regenerative process is dependent on numerous integrated metabolic pathways, which provide the energy required for tissue repair as well as the ability to synthesize the cellular building blocks needed to form new tissue. Therefore, we standardized an extracellular flux analysis method to measure mitochondrial and glycolytic activity in live planarians during normal growth as well as during regeneration. Small, uninjured planarians showed higher rates of oxygen consumption compared with large planarians, with no difference in glycolytic activity; however, glycolysis increased during planarian regeneration. Exposure of planarians to koningic acid, a specific inhibitor of glyceraldehyde‐3‐phosphate dehydrogenase, completely abolished extracellular acidification with little effect on oxygen consumption, which suggests that the majority of glucose catabolized in planarians is fated for aerobic glycolysis. These studies describe a useful method for measuring respiration and glycolysis in planarians and provide data implicating changes in glucose metabolism in the regenerative response.
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Affiliation(s)
- Edie A Osuma
- Wesleyan College Macon GA USA.,Department of Physiology University of Louisville Louisville KY USA
| | - Daniel W Riggs
- Diabetes and Obesity Center, Department of Medicine University of Louisville Louisville KY USA
| | - Andrew A Gibb
- Diabetes and Obesity Center, Department of Medicine University of Louisville Louisville KY USA.,Department of Physiology University of Louisville Louisville KY USA
| | - Bradford G Hill
- Institute of Molecular Cardiology, Diabetes and Obesity Center, Department of Medicine University of Louisville Louisville KY USA.,Diabetes and Obesity Center, Department of Medicine University of Louisville Louisville KY USA.,Department of Physiology University of Louisville Louisville KY USA
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8
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Wang Y, Yu X, Song H, Feng D, Jiang Y, Wu S, Geng J. The STAT-ROS cycle extends IFN‑induced cancer cell apoptosis. Int J Oncol 2017; 52:305-313. [PMID: 29115415 DOI: 10.3892/ijo.2017.4196] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2017] [Accepted: 10/30/2017] [Indexed: 11/06/2022] Open
Abstract
In mammals, the signal transducer and activator of transcription (STAT) protein processes mitochondria importation targets and mitochondria respiratory complexes, and triggers reactive oxygen species (ROS) generation, which conversely rapidly initiates the activation of STAT. Interferon (IFN) administration increases cancer cell apoptosis via STAT activation and ROS accumulation. However, the existence of a STAT-ROS cycle and how it affects IFN‑induced cancer cellular apoptosis are unclear. In the present study, we used MCF7 breast cancer cells and confirmed that a combination of IFN‑α/β/γ incubation induced STAT1/3 phosphorylation and mitochondria importation, which increased mitochondria respiratory complexes, the cellular oxygen consumption rate (OCR), and ROS production, followed by cellular apoptosis. We also found that STAT1/3 overexpression induced mitochondria respiratory complexes and ROS production. Additionally, ROS induced by H2O2 induced phosphorylation of STAT1/3 and promoted mitochondria importation. STAT1/3 deletion suppressed H2O2-induced acute cellular OCR, increasing the ROS level and indicating that STAT1/3 is necessary for ROS-induced mitochondria OCR and further ROS production, suggesting the existence of a STAT-ROS cycle. We next found that IFN induced mitochondria respiratory complexes followed by induction of OCR, ROS, and apoptosis, which were partially blocked by STAT1/3 deletion. Additionally, the suppression of ROS inhibited IFN‑induced STAT1/3 activation. Finally, we discovered that this cycle exists also in A431 and HeLa cancer cells. These results indicate that a STAT-ROS cycle extends IFN‑induced cellular apoptosis.
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Affiliation(s)
- Yan Wang
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150081, P.R. China
| | - Xiaoyu Yu
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150081, P.R. China
| | - Hongtao Song
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150081, P.R. China
| | - Di Feng
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150081, P.R. China
| | - Yang Jiang
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150081, P.R. China
| | - Shuang Wu
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150081, P.R. China
| | - Jingshu Geng
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang 150081, P.R. China
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9
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Integration of flux measurements to resolve changes in anabolic and catabolic metabolism in cardiac myocytes. Biochem J 2017; 474:2785-2801. [PMID: 28706006 PMCID: PMC5545928 DOI: 10.1042/bcj20170474] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/11/2017] [Accepted: 07/12/2017] [Indexed: 12/18/2022]
Abstract
Although ancillary pathways of glucose metabolism are critical for synthesizing cellular building blocks and modulating stress responses, how they are regulated remains unclear. In the present study, we used radiometric glycolysis assays, [13C6]-glucose isotope tracing, and extracellular flux analysis to understand how phosphofructokinase (PFK)-mediated changes in glycolysis regulate glucose carbon partitioning into catabolic and anabolic pathways. Expression of kinase-deficient or phosphatase-deficient 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase in rat neonatal cardiomyocytes co-ordinately regulated glycolytic rate and lactate production. Nevertheless, in all groups, >40% of glucose consumed by the cells was unaccounted for via catabolism to pyruvate, which suggests entry of glucose carbons into ancillary pathways branching from metabolites formed in the preparatory phase of glycolysis. Analysis of 13C fractional enrichment patterns suggests that PFK activity regulates glucose carbon incorporation directly into the ribose and the glycerol moieties of purines and phospholipids, respectively. Pyrimidines, UDP-N-acetylhexosamine, and the fatty acyl chains of phosphatidylinositol and triglycerides showed lower 13C incorporation under conditions of high PFK activity; the isotopologue 13C enrichment pattern of each metabolite indicated limitations in mitochondria-engendered aspartate, acetyl CoA and fatty acids. Consistent with this notion, high glycolytic rate diminished mitochondrial activity and the coupling of glycolysis to glucose oxidation. These findings suggest that a major portion of intracellular glucose in cardiac myocytes is apportioned for ancillary biosynthetic reactions and that PFK co-ordinates the activities of the pentose phosphate, hexosamine biosynthetic, and glycerolipid synthesis pathways by directly modulating glycolytic intermediate entry into auxiliary glucose metabolism pathways and by indirectly regulating mitochondrial cataplerosis.
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10
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Dassanayaka S, Brainard RE, Watson LJ, Long BW, Brittian KR, DeMartino AM, Aird AL, Gumpert AM, Audam TN, Kilfoil PJ, Muthusamy S, Hamid T, Prabhu SD, Jones SP. Cardiomyocyte Ogt limits ventricular dysfunction in mice following pressure overload without affecting hypertrophy. Basic Res Cardiol 2017; 112:23. [PMID: 28299467 PMCID: PMC5555162 DOI: 10.1007/s00395-017-0612-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 03/08/2017] [Indexed: 10/20/2022]
Abstract
The myocardial response to pressure overload involves coordination of multiple transcriptional, posttranscriptional, and metabolic cues. The previous studies show that one such metabolic cue, O-GlcNAc, is elevated in the pressure-overloaded heart, and the increase in O-GlcNAcylation is required for cardiomyocyte hypertrophy in vitro. Yet, it is not clear whether and how O-GlcNAcylation participates in the hypertrophic response in vivo. Here, we addressed this question using patient samples and a preclinical model of heart failure. Protein O-GlcNAcylation levels were increased in myocardial tissue from heart failure patients compared with normal patients. To test the role of OGT in the heart, we subjected cardiomyocyte-specific, inducibly deficient Ogt (i-cmOgt -/-) mice and Ogt competent littermate wild-type (WT) mice to transverse aortic constriction. Deletion of cardiomyocyte Ogt significantly decreased O-GlcNAcylation and exacerbated ventricular dysfunction, without producing widespread changes in metabolic transcripts. Although some changes in hypertrophic and fibrotic signaling were noted, there were no histological differences in hypertrophy or fibrosis. We next determined whether significant differences were present in i-cmOgt -/- cardiomyocytes from surgically naïve mice. Interestingly, markers of cardiomyocyte dedifferentiation were elevated in Ogt-deficient cardiomyocytes. Although no significant differences in cardiac dysfunction were apparent after recombination, it is possible that such changes in dedifferentiation markers could reflect a larger phenotypic shift within the Ogt-deficient cardiomyocytes. We conclude that cardiomyocyte Ogt is not required for cardiomyocyte hypertrophy in vivo; however, loss of Ogt may exert subtle phenotypic differences in cardiomyocytes that sensitize the heart to pressure overload-induced ventricular dysfunction.
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Affiliation(s)
- Sujith Dassanayaka
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Robert E Brainard
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Lewis J Watson
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA.,Kentucky College of Osteopathic Medicine, University of Pikeville, Pikeville, KY, USA
| | - Bethany W Long
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Kenneth R Brittian
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Angelica M DeMartino
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Allison L Aird
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Anna M Gumpert
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Timothy N Audam
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Peter J Kilfoil
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Senthilkumar Muthusamy
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA
| | - Tariq Hamid
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA.,Division of Cardiovascular Disease and Comprehensive Cardiovascular Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sumanth D Prabhu
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA.,Division of Cardiovascular Disease and Comprehensive Cardiovascular Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Steven P Jones
- Division of Cardiovascular Medicine, Department of Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, 580 South Preston Street, Louisville, KY, 40202, USA.
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11
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High glucose induces mitochondrial dysfunction independently of protein O-GlcNAcylation. Biochem J 2015; 467:115-26. [PMID: 25627821 DOI: 10.1042/bj20141018] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Diabetes is characterized by hyperglycaemia and perturbations in intermediary metabolism. In particular, diabetes can augment flux through accessory pathways of glucose metabolism, such as the hexosamine biosynthetic pathway (HBP), which produces the sugar donor for the β-O-linked-N-acetylglucosamine (O-GlcNAc) post-translational modification of proteins. Diabetes also promotes mitochondrial dysfunction. Nevertheless, the relationships among diabetes, hyperglycaemia, mitochondrial dysfunction and O-GlcNAc modifications remain unclear. In the present study, we tested whether high-glucose-induced increases in O-GlcNAc modifications directly regulate mitochondrial function in isolated cardiomyocytes. Augmentation of O-GlcNAcylation with high glucose (33 mM) was associated with diminished basal and maximal cardiomyocyte respiration, a decreased mitochondrial reserve capacity and lower Complex II-dependent respiration (P<0.05); however, pharmacological or genetic modulation of O-GlcNAc modifications under normal or high glucose conditions showed few significant effects on mitochondrial respiration, suggesting that O-GlcNAc does not play a major role in regulating cardiomyocyte mitochondrial function. Furthermore, an osmotic control recapitulated high-glucose-induced changes to mitochondrial metabolism (P<0.05) without increasing O-GlcNAcylation. Thus, increased O-GlcNAcylation is neither sufficient nor necessary for high-glucose-induced suppression of mitochondrial metabolism in isolated cardiomyocytes.
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12
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Salabei JK, Lorkiewicz PK, Holden CR, Li Q, Hong KU, Bolli R, Bhatnagar A, Hill BG. Glutamine Regulates Cardiac Progenitor Cell Metabolism and Proliferation. Stem Cells 2015; 33:2613-27. [PMID: 25917428 DOI: 10.1002/stem.2047] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 03/08/2015] [Accepted: 03/29/2015] [Indexed: 12/27/2022]
Abstract
Autologous transplantation of cardiac progenitor cells (CPCs) alleviates myocardial dysfunction in the damaged heart; however, the mechanisms that contribute to their reparative qualities remain poorly understood. In this study, we examined CPC metabolism to elucidate the metabolic pathways that regulate their proliferative capacity. In complete growth medium, undifferentiated CPCs isolated from adult mouse heart proliferated rapidly (Td = 13.8 hours). CPCs expressed the Glut1 transporter and their glycolytic rate was increased by high extracellular glucose (Glc) concentration, in the absence of insulin. Although high Glc concentrations did not stimulate proliferation, glutamine (Gln) increased CPC doubling time and promoted survival under conditions of oxidative stress. In comparison with Glc, pyruvate (Pyr) or BSA-palmitate, Gln, when provided as the sole metabolic substrate, increased ATP-linked and uncoupled respiration. Although fatty acids were not used as respiratory substrates when present as a sole carbon source, Gln-induced respiration was doubled in the presence of BSA-palmitate, suggesting that Gln stimulates fatty acid oxidation. Additionally, Gln promoted rapid phosphorylation of the mTORC1 substrate, p70S6k, as well as retinoblastoma protein, followed by induction of cyclin D1 and cdk4. Inhibition of either mTORC1 or glutaminolysis was sufficient to diminish CPC proliferation, and provision of cell permeable α-ketoglutarate in the absence of Gln increased both respiration and cell proliferation, indicating a key role of Gln anaplerosis in cell growth. These findings suggest that Gln, by enhancing mitochondrial function and stimulating mTORC1, increases CPC proliferation, and that interventions to increase Gln uptake or oxidation may improve CPC therapy.
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Affiliation(s)
- Joshua K Salabei
- Department of Medicine, Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, USA.,Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, Kentucky, USA
| | - Pawel K Lorkiewicz
- Department of Medicine, Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, USA.,Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, Kentucky, USA
| | - Candice R Holden
- Department of Medicine, Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, USA.,Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, Kentucky, USA.,Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky, USA
| | - Qianhong Li
- Department of Medicine, Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, USA
| | - Kyung U Hong
- Department of Medicine, Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, USA
| | - Roberto Bolli
- Department of Medicine, Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, USA.,Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, Kentucky, USA.,Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky, USA
| | - Aruni Bhatnagar
- Department of Medicine, Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, USA.,Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, Kentucky, USA.,Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky, USA.,Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, Kentucky, USA
| | - Bradford G Hill
- Department of Medicine, Institute of Molecular Cardiology, University of Louisville, Louisville, Kentucky, USA.,Department of Medicine, Diabetes and Obesity Center, University of Louisville, Louisville, Kentucky, USA.,Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky, USA.,Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, Kentucky, USA
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13
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Levonen AL, Hill BG, Kansanen E, Zhang J, Darley-Usmar VM. Redox regulation of antioxidants, autophagy, and the response to stress: implications for electrophile therapeutics. Free Radic Biol Med 2014; 71:196-207. [PMID: 24681256 PMCID: PMC4042208 DOI: 10.1016/j.freeradbiomed.2014.03.025] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 03/06/2014] [Accepted: 03/12/2014] [Indexed: 12/21/2022]
Abstract
Redox networks in the cell integrate signaling pathways that control metabolism, energetics, cell survival, and death. The physiological second messengers that modulate these pathways include nitric oxide, hydrogen peroxide, and electrophiles. Electrophiles are produced in the cell via both enzymatic and nonenzymatic lipid peroxidation and are also relatively abundant constituents of the diet. These compounds bind covalently to families of cysteine-containing, redox-sensing proteins that constitute the electrophile-responsive proteome, the subproteomes of which are found in localized intracellular domains. These include those proteins controlling responses to oxidative stress in the cytosol-notably the Keap1-Nrf2 pathway, the autophagy-lysosomal pathway, and proteins in other compartments including mitochondria and endoplasmic reticulum. The signaling pathways through which electrophiles function have unique characteristics that could be exploited for novel therapeutic interventions; however, development of such therapeutic strategies has been challenging due to a lack of basic understanding of the mechanisms controlling this form of redox signaling. In this review, we discuss current knowledge of the basic mechanisms of thiol-electrophile signaling and its potential impact on the translation of this important field of redox biology to the clinic. Emerging understanding of thiol-electrophile interactions and redox signaling suggests replacement of the oxidative stress hypothesis with a new redox biology paradigm, which provides an exciting and influential framework for guiding translational research.
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Affiliation(s)
- Anna-Liisa Levonen
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Bradford G Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, and Department of Medicine, University of Louisville, Louisville, KY, USA; Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, KY, USA; Department of Physiology and Biophysics, University of Louisville, Louisville, KY, USA
| | - Emilia Kansanen
- Department of Biotechnology and Molecular Medicine, A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Jianhua Zhang
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA; Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294, USA; Department of Veteran Affairs Medical Center, Birmingham, AL 35294, USA
| | - Victor M Darley-Usmar
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294, USA; Department of Veteran Affairs Medical Center, Birmingham, AL 35294, USA.
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14
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Salabei JK, Gibb AA, Hill BG. Comprehensive measurement of respiratory activity in permeabilized cells using extracellular flux analysis. Nat Protoc 2014; 9:421-38. [PMID: 24457333 DOI: 10.1038/nprot.2014.018] [Citation(s) in RCA: 233] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Extracellular flux (XF) analysis has become a mainstream method for measuring mitochondrial function in cells and tissues. Although this technique is commonly used to measure bioenergetics in intact cells, we outline here a detailed XF protocol for measuring respiration in permeabilized cells. Cells are permeabilized using saponin (SAP), digitonin (DIG) or recombinant perfringolysin O (rPFO) (XF-plasma membrane permeabilizer (PMP) reagent), and they are provided with specific substrates to measure complex I- or complex II-mediated respiratory activity, complex III+IV respiratory activity or complex IV activity. Medium- and long-chain acylcarnitines or glutamine may also be provided for measuring fatty acid (FA) oxidation or glutamine oxidation, respectively. This protocol uses a minimal number of cells compared with other protocols and does not require isolation of mitochondria. The results are highly reproducible, and mitochondria remain well coupled. Collectively, this protocol provides comprehensive and detailed information regarding mitochondrial activity and efficiency, and, after preparative steps, it takes 6-8 h to complete.
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Affiliation(s)
- Joshua K Salabei
- Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Andrew A Gibb
- 1] Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, Kentucky, USA. [2] Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky, USA
| | - Bradford G Hill
- 1] Diabetes and Obesity Center, Institute of Molecular Cardiology, University of Louisville School of Medicine, Louisville, Kentucky, USA. [2] Department of Physiology and Biophysics, University of Louisville School of Medicine, Louisville, Kentucky, USA. [3] Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, Kentucky, USA
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15
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Yu H, Tigchelaar W, Koonen DPY, Patel HH, de Boer RA, van Gilst WH, Westenbrink BD, Silljé HHW. AKIP1 expression modulates mitochondrial function in rat neonatal cardiomyocytes. PLoS One 2013; 8:e80815. [PMID: 24236204 PMCID: PMC3827472 DOI: 10.1371/journal.pone.0080815] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/05/2013] [Indexed: 11/18/2022] Open
Abstract
A kinase interacting protein 1 (AKIP1) is a molecular regulator of protein kinase A and nuclear factor kappa B signalling. Recent evidence suggests AKIP1 is increased in response to cardiac stress, modulates acute ischemic stress response, and is localized to mitochondria in cardiomyocytes. The mitochondrial function of AKIP1 is, however, still elusive. Here, we investigated the mitochondrial function of AKIP1 in a neonatal cardiomyocyte model of phenylephrine (PE)-induced hypertrophy. Using a seahorse flux analyzer we show that PE stimulated the mitochondrial oxygen consumption rate (OCR) in cardiomyocytes. This was partially dependent on PE mediated AKIP1 induction, since silencing of AKIP1 attenuated the increase in OCR. Interestingly, AKIP1 overexpression alone was sufficient to stimulate mitochondrial OCR and in particular ATP-linked OCR. This was also true when pyruvate was used as a substrate, indicating that it was independent of glycolytic flux. The increase in OCR was independent of mitochondrial biogenesis, changes in ETC density or altered mitochondrial membrane potential. In fact, the respiratory flux was elevated per amount of ETC, possibly through enhanced ETC coupling. Furthermore, overexpression of AKIP1 reduced and silencing of AKIP1 increased mitochondrial superoxide production, suggesting that AKIP1 modulates the efficiency of electron flux through the ETC. Together, this suggests that AKIP1 overexpression improves mitochondrial function to enhance respiration without excess superoxide generation, thereby implicating a role for AKIP1 in mitochondrial stress adaptation. Upregulation of AKIP1 during different forms of cardiac stress may therefore be an adaptive mechanism to protect the heart.
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Affiliation(s)
- Hongjuan Yu
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- Department of Hematology, the First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Wardit Tigchelaar
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Debby P. Y. Koonen
- Molecular Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Hemal H. Patel
- VA San Diego Healthcare System, San Diego, California, United States of America
- Department of Anesthesiology, University of California San Diego, San Diego, California, United States of America
| | - Rudolf A. de Boer
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Wiek H. van Gilst
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - B. Daan Westenbrink
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Herman H. W. Silljé
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
- * E-mail:
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Watson LJ, Long BW, DeMartino AM, Brittian KR, Readnower RD, Brainard RE, Cummins TD, Annamalai L, Hill BG, Jones SP. Cardiomyocyte Ogt is essential for postnatal viability. Am J Physiol Heart Circ Physiol 2013; 306:H142-53. [PMID: 24186210 DOI: 10.1152/ajpheart.00438.2013] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The singly coded gene O-linked-β-N-acetylglucosamine (O-GlcNAc) transferase (Ogt) resides on the X chromosome and is necessary for embryonic stem cell viability during embryogenesis. In mature cells, this enzyme catalyzes the posttranslational modification known as O-GlcNAc to various cellular proteins. Several groups, including our own, have shown that acute increases in protein O-GlcNAcylation are cardioprotective both in vitro and in vivo. Yet, little is known about how OGT affects cardiac function because total body knockout (KO) animals are not viable. Presently, we sought to establish the potential involvement of cardiomyocyte Ogt in cardiac maturation. Initially, we characterized a constitutive cardiomyocyte-specific (cm)OGT KO (c-cmOGT KO) mouse and found that only 12% of the c-cmOGT KO mice survived to weaning age (4 wk old); the surviving animals were smaller than their wild-type littermates, had dilated hearts, and showed overt signs of heart failure. Dysfunctional c-cmOGT KO hearts were more fibrotic, apoptotic, and hypertrophic. Several glycolytic genes were also upregulated; however, there were no gross changes in mitochondrial O2 consumption. Histopathology of the KO hearts indicated the potential involvement of endoplasmic reticulum stress, directing us to evaluate expression of 78-kDa glucose-regulated protein and protein disulfide isomerase, which were elevated. Additional groups of mice were subjected to inducible deletion of cmOGT, which did not produce overt dysfunction within the first couple of weeks of deletion. Yet, long-term loss (via inducible deletion) of cmOGT produced gradual and progressive cardiomyopathy. Thus, cardiomyocyte Ogt is necessary for maturation of the mammalian heart, and inducible deletion of cmOGT in the adult mouse produces progressive ventricular dysfunction.
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Affiliation(s)
- Lewis J Watson
- Department of Physiology and Biophysics, University of Louisville, Louisville, Kentucky; and
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17
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Zafir A, Readnower R, Long BW, McCracken J, Aird A, Alvarez A, Cummins TD, Li Q, Hill BG, Bhatnagar A, Prabhu SD, Bolli R, Jones SP. Protein O-GlcNAcylation is a novel cytoprotective signal in cardiac stem cells. Stem Cells 2013; 31:765-75. [PMID: 23335157 DOI: 10.1002/stem.1325] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2012] [Accepted: 12/14/2012] [Indexed: 01/02/2023]
Abstract
Clinical trials demonstrate the regenerative potential of cardiac stem cell (CSC) therapy in the postinfarcted heart. Despite these encouraging preliminary clinical findings, the basic biology of these cells remains largely unexplored. The principal requirement for cell transplantation is to effectively prime them for survival within the unfavorable environment of the infarcted myocardium. In the adult mammalian heart, the β-O-linkage of N-acetylglucosamine (i.e., O-GlcNAc) to proteins is a unique post-translational modification that confers cardioprotection from various otherwise lethal stressors. It is not known whether this signaling system exists in CSCs. In this study, we demonstrate that protein O-GlcNAcylation is an inducible stress response in adult murine Sca-1(+) /lin(-) CSCs and exerts an essential prosurvival role. Posthypoxic CSCs responded by time-dependently increasing protein O-GlcNAcylation upon reoxygenation. We used pharmacological interventions for loss- and gain-of-function, that is, enzymatic inhibition of O-GlcNAc transferase (OGT) (adds the O-GlcNAc modification to proteins) by TT04, or inhibition of OGA (removes O-GlcNAc) by thiamet-G (ThG). Reduction in the O-GlcNAc signal (via TT04, or OGT gene deletion using Cre-mediated recombination) significantly sensitized CSCs to posthypoxic injury, whereas augmenting O-GlcNAc levels (via ThG) enhanced cell survival. Diminished O-GlcNAc levels render CSCs more susceptible to the onset of posthypoxic apoptotic processes via elevated poly(ADP-ribose) polymerase cleavage due to enhanced caspase-3/7 activation, whereas promoting O-GlcNAcylation can serve as a pre-emptive antiapoptotic signal regulating the survival of CSCs. Thus, we report the primary demonstration of protein O-GlcNAcylation as an important prosurvival signal in CSCs, which could enhance CSC survival prior to in vivo autologous transfer.
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Affiliation(s)
- Ayesha Zafir
- Department of Medicine, Division of Cardiovascular Medicine, Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, Louisville, Kentucky 40202, USA
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18
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Chang YW, Chang YT, Wang Q, Lin JJC, Chen YJ, Chen CC. Quantitative phosphoproteomic study of pressure-overloaded mouse heart reveals dynamin-related protein 1 as a modulator of cardiac hypertrophy. Mol Cell Proteomics 2013; 12:3094-107. [PMID: 23882026 DOI: 10.1074/mcp.m113.027649] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Pressure-overload stress to the heart causes pathological cardiac hypertrophy, which increases the risk of cardiac morbidity and mortality. However, the detailed signaling pathways induced by pressure overload remain unclear. Here we used phosphoproteomics to delineate signaling pathways in the myocardium responding to acute pressure overload and chronic hypertrophy in mice. Myocardial samples at 4 time points (10, 30, 60 min and 2 weeks) after transverse aortic banding (TAB) in mice underwent quantitative phosphoproteomics assay. Temporal phosphoproteomics profiles showed 360 phosphorylation sites with significant regulation after TAB. Multiple mechanical stress sensors were activated after acute pressure overload. Gene ontology analysis revealed differential phosphorylation between hearts with acute pressure overload and chronic hypertrophy. Most interestingly, analysis of the cardiac hypertrophy pathway revealed phosphorylation of the mitochondrial fission protein dynamin-related protein 1 (DRP1) by prohypertrophic kinases. Phosphorylation of DRP1 S622 was confirmed in TAB-treated mouse hearts and phenylephrine (PE)-treated rat neonatal cardiomyocytes. TAB-treated mouse hearts showed phosphorylation-mediated mitochondrial translocation of DRP1. Inhibition of DRP1 with the small-molecule inhibitor mdivi-1 reduced the TAB-induced hypertrophic responses. Mdivi-1 also prevented PE-induced hypertrophic growth and oxygen consumption in rat neonatal cardiomyocytes. We reveal the signaling responses of the heart to pressure stress in vivo and in vitro. DRP1 may be important in the development of cardiac hypertrophy.
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Affiliation(s)
- Yu-Wang Chang
- Molecular Medicine Program, Taiwan International Graduate Program, Institute of Biomedical Sciences, Academia Sinica, Taipei 115, Taiwan
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19
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Malondialdehyde and 4-hydroxynonenal adducts are not formed on cardiac ryanodine receptor (RyR2) and sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA2) in diabetes. Mol Cell Biochem 2013; 376:121-35. [PMID: 23354458 DOI: 10.1007/s11010-013-1558-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Accepted: 01/09/2013] [Indexed: 12/31/2022]
Abstract
Recently, we reported an elevated level of glucose-generated carbonyl adducts on cardiac ryanodine receptor (RyR2) and sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2) in hearts of streptozotocin(STZ)-induced diabetic rats. We also showed these adduct impaired RyR2 and SERCA2 activities, and altered evoked Ca(2+) transients. What is less clear is if lipid-derived malondialdehyde (MDA) and 4-hydroxy-2-nonenal (4-HNE) also chemically react with and impair RyR2 and SERCA2 activities in diabetes? This study used western blot assays with adduct-specific antibodies and confocal microscopy to assess levels of MDA, 4-HNE, N (ε)-carboxy(methyl)lysine (CML), pentosidine, and pyrraline adducts on RyR2 and SERCA2 and evoked intracellular transient Ca(2+) kinetics in myocytes from control, diabetic, and treated-diabetic rats. MDA and 4-HNE adducts were not detected on RyR2 and SERCA2 from either control or 8 weeks diabetic rats with altered evoked Ca(2+) transients. However, CML, pentosidine, and pyrraline adducts were elevated three- to five-fold (p < 0.05). Treating diabetic rats with pyridoxamine (a scavenger of reactive carbonyl species, RCS) or aminoguanidine (a mixed reactive oxygen species-RCS scavenger) reduced CML, pentosidine, and pyrraline adducts on RyR2 and SERCA2 and blunted SR Ca(2+) cycling changes. Treating diabetic rats with the superoxide dismutase mimetic tempol had no impact on MDA and 4-HNE adducts on RyR2 and SERCA2, and on SR Ca(2+) cycling. From these data we conclude that lipid-derived MDA and 4-HNE adducts are not formed on RyR2 and SERCA2 in this model of diabetes, and are therefore unlikely to be directly contributing to the SR Ca(2+) dysregulation.
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21
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Hill BG, Benavides GA, Lancaster JR, Ballinger S, Dell’Italia L, Zhang J, Darley-Usmar VM. Integration of cellular bioenergetics with mitochondrial quality control and autophagy. Biol Chem 2012; 393:1485-1512. [PMID: 23092819 PMCID: PMC3594552 DOI: 10.1515/hsz-2012-0198] [Citation(s) in RCA: 346] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Accepted: 06/22/2012] [Indexed: 02/06/2023]
Abstract
Bioenergetic dysfunction is emerging as a cornerstone for establishing a framework for understanding the pathophysiology of cardiovascular disease, diabetes,cancer and neurodegeneration. Recent advances in cellular bioenergetics have shown that many cells maintain a substantial bioenergetic reserve capacity, which is a prospective index of ‘ healthy ’ mitochondrial populations.The bioenergetics of the cell are likely regulated by energy requirements and substrate availability. Additionally,the overall quality of the mitochondrial population and the relative abundance of mitochondria in cells and tissues also impinge on overall bioenergetic capacity and resistance to stress. Because mitochondria are susceptible to damage mediated by reactive oxygen/nitrogen and lipid species, maintaining a ‘ healthy ’ population of mitochondria through quality control mechanisms appears to be essential for cell survival under conditions of pathological stress. Accumulating evidence suggest that mitophagy is particularly important for preventing amplification of initial oxidative insults, which otherwise would further impair the respiratory chain or promote mutations in mitochondrial DNA (mtDNA). The processes underlying the regulation of mitophagy depend on several factors, including the integrity of mtDNA, electron transport chain activity, and the interaction and regulation of the autophagic machinery. The integration and interpretation of cellular bioenergetics in the context of mitochondrial quality control and genetics is the theme of this review.
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Affiliation(s)
- Bradford G. Hill
- Diabetes and Obesity Center, Institute of Molecular Cardiology, and Department of Medicine, University of Louisville, Louisville, KY
- Departments of Biochemistry and Molecular Biology and Physiology and Biophysics, University of Louisville, Louisville, KY
| | - Gloria A. Benavides
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Jack R. Lancaster
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Anesthesiology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Physiology and Biophysics, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Scott Ballinger
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Medicine, Center for Heart Failure Research, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Lou Dell’Italia
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Medicine, Center for Heart Failure Research, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Veteran Affairs Medical Center, Birmingham, AL 35294
| | - Jianhua Zhang
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Veteran Affairs Medical Center, Birmingham, AL 35294
| | - Victor M. Darley-Usmar
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
- Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Medicine, Center for Heart Failure Research, University of Alabama at Birmingham, Birmingham, AL 35294
- Department of Environmental Health Sciences, University of Alabama at Birmingham, Birmingham, AL 35294
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22
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Readnower RD, Brainard RE, Hill BG, Jones SP. Standardized bioenergetic profiling of adult mouse cardiomyocytes. Physiol Genomics 2012; 44:1208-13. [PMID: 23092951 DOI: 10.1152/physiolgenomics.00129.2012] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Mitochondria are at the crux of life and death and as such have become ideal targets of intervention in cardiovascular disease. Generally, current methods to measure mitochondrial dysfunction rely on working with the isolated organelle and fail to incorporate mitochondrial function in a cellular context. Extracellular flux methodology has been particularly advantageous in this respect; however, certain primary cell types, such as adult cardiac myocytes, have been difficult to standardize with this technology. Here, we describe methods for using extracellular flux (XF) analysis to measure mitochondrial bioenergetics in isolated, intact, adult mouse cardiomyocytes (ACMs). Following isolation, ACMs were seeded overnight onto laminin-coated (20 μg/ml) microplates, which resulted in high attachment efficiency. After establishing seeding density, we found that a commonly used assay medium (containing a supraphysiological concentration of pyruvate at 1 mmol/l) produced a maximal bioenergetic response. After performing a pyruvate dose-response, we determined that pyruvate titrated to 0.1 mmol/l was optimal for examining alternative substrate oxidation. Methods for measuring fatty acid oxidation were established. These methods lay the framework using XF analysis to profile metabolism of ACMs and will likely augment our ability to understand mitochondrial dysfunction in heart failure and acute myocardial ischemia. This platform could easily be extended to models of diabetes or other metabolic defects.
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Affiliation(s)
- Ryan D Readnower
- Institute of Molecular Cardiology, Diabetes and Obesity Center, University of Louisville, Louisville, Kentucky 40202, USA
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Schneider L, Giordano S, Zelickson BR, Johnson M, Benavides G, Ouyang X, Fineberg N, Darley-Usmar VM, Zhang J. Differentiation of SH-SY5Y cells to a neuronal phenotype changes cellular bioenergetics and the response to oxidative stress. Free Radic Biol Med 2011; 51:2007-17. [PMID: 21945098 PMCID: PMC3208787 DOI: 10.1016/j.freeradbiomed.2011.08.030] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 08/23/2011] [Accepted: 08/24/2011] [Indexed: 12/13/2022]
Abstract
Cell differentiation is associated with changes in metabolism and function. Understanding these changes during differentiation is important in the context of stem cell research, cancer, and neurodegenerative diseases. An early event in neurodegenerative diseases is the alteration of mitochondrial function and increased oxidative stress. Studies using both undifferentiated and differentiated SH-SY5Y neuroblastoma cells have shown distinct responses to cellular stressors; however, the mechanisms remain unclear. We hypothesized that because the regulation of glycolysis and oxidative phosphorylation is modulated during cellular differentiation, this would change bioenergetic function and the response to oxidative stress. To test this, we used retinoic acid (RA) to induce differentiation of SH-SY5Y cells and assessed changes in cellular bioenergetics using extracellular flux analysis. After exposure to RA, the SH-SY5Y cells had an increased mitochondrial membrane potential, without changing mitochondrial number. Differentiated cells exhibited greater stimulation of mitochondrial respiration with uncoupling and an increased bioenergetic reserve capacity. The increased reserve capacity in the differentiated cells was suppressed by the inhibitor of glycolysis 2-deoxy-d-glucose. Furthermore, we found that differentiated cells were substantially more resistant to cytotoxicity and mitochondrial dysfunction induced by the reactive lipid species 4-hydroxynonenal or the reactive oxygen species generator 2,3-dimethoxy-1,4-naphthoquinone. We then analyzed the levels of selected mitochondrial proteins and found an increase in complex IV subunits, which we propose contributes to the increase in reserve capacity in the differentiated cells. Furthermore, we found an increase in MnSOD that could, at least in part, account for the increased resistance to oxidative stress. Our findings suggest that profound changes in mitochondrial metabolism and antioxidant defenses occur upon differentiation of neuroblastoma cells to a neuron-like phenotype.
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Affiliation(s)
- Lonnie Schneider
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Samantha Giordano
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Blake R. Zelickson
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Michelle Johnson
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Gloria Benavides
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Xiaosen Ouyang
- Department of Pathology, University of Alabama at Birmingham
- Department of Veterans Affairs, Birmingham VA Medical Center
| | - Naomi Fineberg
- Department of Biostatistics, UAB School of Public Health
| | - Victor M. Darley-Usmar
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Jianhua Zhang
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
- Department of Veterans Affairs, Birmingham VA Medical Center
- Corresponding author: Jianhua Zhang, Ph.D., Department of Pathology, University of Alabama at Birmingham, BMRII-534, 901 19 Street South, Birmingham, AL 35294-0017, USA, Phone: 205-996-5153; Fax: 205-934-7447;
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24
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Dranka BP, Benavides GA, Diers AR, Giordano S, Zelickson BR, Reily C, Zou L, Chatham JC, Hill BG, Zhang J, Landar A, Darley-Usmar VM. Assessing bioenergetic function in response to oxidative stress by metabolic profiling. Free Radic Biol Med 2011; 51:1621-35. [PMID: 21872656 PMCID: PMC3548422 DOI: 10.1016/j.freeradbiomed.2011.08.005] [Citation(s) in RCA: 344] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Revised: 08/08/2011] [Accepted: 08/09/2011] [Indexed: 12/22/2022]
Abstract
It is now clear that mitochondria are an important target for oxidative stress in a broad range of pathologies, including cardiovascular disease, diabetes, neurodegeneration, and cancer. Methods for assessing the impact of reactive species on isolated mitochondria are well established but constrained by the need for large amounts of material to prepare intact mitochondria for polarographic measurements. With the availability of high-resolution polarography and fluorescence techniques for the measurement of oxygen concentration in solution, measurements of mitochondrial function in intact cells can be made. Recently, the development of extracellular flux methods to monitor changes in oxygen concentration and pH in cultures of adherent cells in multiple-sample wells simultaneously has greatly enhanced the ability to measure bioenergetic function in response to oxidative stress. Here we describe these methods in detail using representative cell types from renal, cardiovascular, nervous, and tumorigenic model systems while illustrating the application of three protocols to analyze the bioenergetic response of cells to oxidative stress.
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Affiliation(s)
- Brian P. Dranka
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Gloria A. Benavides
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Anne R. Diers
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Samantha Giordano
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Blake R. Zelickson
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Colin Reily
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Luyun Zou
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - John C. Chatham
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Bradford G. Hill
- Department of Cardiovascular Medicine, University of Louisville, Louisville, KY 40202
| | - Jianhua Zhang
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Aimee Landar
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Victor M. Darley-Usmar
- Department of Pathology and Center for Free Radical Biology, University of Alabama at Birmingham, Birmingham, AL 35294
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