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Shaul D, Lev-Cohain N, Sapir G, Sosna J, Gomori JM, Joskowicz L, Katz-Brull R. Real-time influence of intracellular acidification and Na + /H + exchanger inhibition on in-cell pyruvate metabolism in the perfused mouse heart: A 31 P-NMR and hyperpolarized 13 C-NMR study. NMR IN BIOMEDICINE 2023; 36:e4993. [PMID: 37424280 DOI: 10.1002/nbm.4993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 05/31/2023] [Accepted: 06/01/2023] [Indexed: 07/11/2023]
Abstract
Disruption of acid-base balance is linked to various diseases and conditions. In the heart, intracellular acidification is associated with heart failure, maladaptive cardiac hypertrophy, and myocardial ischemia. Previously, we have reported that the ratio of the in-cell lactate dehydrogenase (LDH) to pyruvate dehydrogenase (PDH) activities is correlated with cardiac pH. To further characterize the basis for this correlation, these in-cell activities were investigated under induced intracellular acidification without and with Na+ /H+ exchanger (NHE1) inhibition by zoniporide. Male mouse hearts (n = 30) were isolated and perfused retrogradely. Intracellular acidification was performed in two ways: (1) with the NH4 Cl prepulse methodology; and (2) by combining the NH4 Cl prepulse with zoniporide. 31 P NMR spectroscopy was used to determine the intracellular cardiac pH and to quantify the adenosine triphosphate and phosphocreatine content. Hyperpolarized [1-13 C]pyruvate was obtained using dissolution dynamic nuclear polarization. 13 C NMR spectroscopy was used to monitor hyperpolarized [1-13 C]pyruvate metabolism and determine enzyme activities in real time at a temporal resolution of a few seconds using the product-selective saturating excitation approach. The intracellular acidification induced by the NH4 Cl prepulse led to reduced LDH and PDH activities (-16% and -39%, respectively). This finding is in line with previous evidence of reduced myocardial contraction and therefore reduced metabolic activity upon intracellular acidification. Concomitantly, the LDH/PDH activity ratio increased with the reduction in pH, as previously reported. Combining the NH4 Cl prepulse with zoniporide led to a greater reduction in LDH activity (-29%) and to increased PDH activity (+40%). These changes resulted in a surprising decrease in the LDH/PDH ratio, as opposed to previous predictions. Zoniporide alone (without intracellular acidification) did not change these enzyme activities. A possible explanation for the enzymatic changes observed during the combination of the NH4 Cl prepulse and NHE1 inhibition may be related to mitochondrial NHE1 inhibition, which likely negates the mitochondrial matrix acidification. This effect, combined with the increased acidity in the cytosol, would result in an enhanced H+ gradient across the mitochondrial membrane and a temporarily higher pyruvate transport into the mitochondria, thereby increasing the PDH activity at the expense of the cytosolic LDH activity. These findings demonstrate the complexity of in-cell cardiac metabolism and its dependence on intracellular acidification. This study demonstrates the capabilities and limitations of hyperpolarized [1-13 C]pyruvate in the characterization of intracellular acidification as regards cardiac pathologies.
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Affiliation(s)
- David Shaul
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- The Wohl Institute for Translational Medicine, Hadassah Medical Organization, Jerusalem, Israel
| | - Naama Lev-Cohain
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Gal Sapir
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- The Wohl Institute for Translational Medicine, Hadassah Medical Organization, Jerusalem, Israel
| | - Jacob Sosna
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - J Moshe Gomori
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Leo Joskowicz
- School of Computer Science and Engineering, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rachel Katz-Brull
- Department of Radiology, Hadassah Medical Organization and Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
- The Wohl Institute for Translational Medicine, Hadassah Medical Organization, Jerusalem, Israel
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2
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Dasgupta S, Ghosh N, Choudhury P, Joshi M, Chowdhury SR, Bhattacharyya P, Chaudhury K. NMR metabolomic and microarray-based transcriptomic data integration identifies unique molecular signatures of hypersensitivity pneumonitis. Mol Omics 2021; 18:101-111. [PMID: 34881764 DOI: 10.1039/d1mo00209k] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hypersensitivity pneumonitis (HP) is an immune-mediated granulomatous interstitial lung disease (ILD) that results from repeated inhalation of certain antigens. Despite major advances in research, pathophysiology of the disease remains poorly understood. The present study combines metabolomic and transcriptomic data to determine alterations in HP subjects as compared with healthy controls. Metabolic signatures were identified in serum, exhaled breath condensate (EBC) and bronchoalveolar lavage fluid (BALF) of HP patients using proton nuclear magnetic resonance (NMR) metabolomics. The expression of three metabolites, i.e., lactate, pyruvate, and proline, was found to be significantly altered in all three biofluids. The potential of differential diagnosis based on these three metabolites was investigated by including a group of patients with sarcoidosis, which is another type of granulomatous ILD. In addition, differentially expressed transcriptomic fingerprints in blood samples were identified by analyzing a Gene Expression Omnibus (GEO) database. The transcriptomics analysis of these microarray-based data revealed 59 genes to be significantly dysregulated in patients with HP. Over representation analysis of the metabolites and genes of interest was performed using IMPaLA (Integrated Molecular Pathway Level Analysis) version 12. Integrated analysis of serum metabolite signatures and blood gene expression suggests dysregulation of PI3K-AKT signaling and TCA cycle pathways in these patients. This preliminary study is a step towards better understanding of the pathogenesis of HP by identification of differentially expressed metabolites and transcriptomic fingerprints. These molecular signatures may be explored as diagnostic markers for differentiating HP from other lung diseases.
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Affiliation(s)
- Sanjukta Dasgupta
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, 721302, India.
| | - Nilanjana Ghosh
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, 721302, India.
| | - Priyanka Choudhury
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, 721302, India.
| | - Mamata Joshi
- National Facility for High-field NMR, Tata Institute of Fundamental Research, Mumbai, India
| | | | | | - Koel Chaudhury
- School of Medical Science and Technology, Indian Institute of Technology Kharagpur, 721302, India.
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Sharma G, Wen X, Maptue NR, Hever T, Malloy CR, Sherry AD, Khemtong C. Co-Polarized [1- 13C]Pyruvate and [1,3- 13C 2]Acetoacetate Provide a Simultaneous View of Cytosolic and Mitochondrial Redox in a Single Experiment. ACS Sens 2021; 6:3967-3977. [PMID: 34761912 DOI: 10.1021/acssensors.1c01225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Cellular redox is intricately linked to energy production and normal cell function. Although the redox states of mitochondria and cytosol are connected by shuttle mechanisms, the redox state of mitochondria may differ from redox in the cytosol in response to stress. However, detecting these differences in functioning tissues is difficult. Here, we employed 13C magnetic resonance spectroscopy (MRS) and co-polarized [1-13C]pyruvate and [1,3-13C2]acetoacetate ([1,3-13C2]AcAc) to monitor production of hyperpolarized (HP) lactate and β-hydroxybutyrate as indicators of cytosolic and mitochondrial redox, respectively. Isolated rat hearts were examined under normoxic conditions, during low-flow ischemia, and after pretreatment with either aminooxyacetate (AOA) or rotenone. All interventions were associated with an increase in [Pi]/[ATP] measured by 31P NMR. In well-oxygenated untreated hearts, rapid conversion of HP [1-13C]pyruvate to [1-13C]lactate and [1,3-13C2]AcAc to [1,3-13C2]β-hydroxybutyrate ([1,3-13C2]β-HB) was readily detected. A significant increase in HP [1,3-13C2]β-HB but not [1-13C]lactate was observed in rotenone-treated and ischemic hearts, consistent with an increase in mitochondrial NADH but not cytosolic NADH. AOA treatments did not alter the productions of HP [1-13C]lactate or [1,3-13C2]β-HB. This study demonstrates that biomarkers of mitochondrial and cytosolic redox may be detected simultaneously in functioning tissues using co-polarized [1-13C]pyruvate and [1,3-13C2]AcAc and 13C MRS and that changes in mitochondrial redox may precede changes in cytosolic redox.
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Affiliation(s)
- Gaurav Sharma
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Xiaodong Wen
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Nesmine R. Maptue
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Thomas Hever
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Craig R. Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - A. Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Chalermchai Khemtong
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Medicine, Division of Endocrinology, Diabetes and Metabolism, University of Florida, Gainesville, Florida 32610, United States
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610, United States
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Sousa Fialho MDL, Purnama U, Dennis KMJH, Montes Aparicio CN, Castro-Guarda M, Massourides E, Tyler DJ, Carr CA, Heather LC. Activation of HIF1α Rescues the Hypoxic Response and Reverses Metabolic Dysfunction in the Diabetic Heart. Diabetes 2021; 70:2518-2531. [PMID: 34526367 PMCID: PMC8564414 DOI: 10.2337/db21-0398] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/27/2021] [Indexed: 11/13/2022]
Abstract
Type 2 diabetes (T2D) impairs hypoxia-inducible factor (HIF)1α activation, a master transcription factor that drives cellular adaptation to hypoxia. Reduced activation of HIF1α contributes to the impaired post-ischemic remodeling observed following myocardial infarction in T2D. Molidustat is an HIF stabilizer currently undergoing clinical trials for the treatment of renal anemia associated with chronic kidney disease; however, it may provide a route to pharmacologically activate HIF1α in the T2D heart. In human cardiomyocytes, molidustat stabilized HIF1α and downstream HIF target genes, promoting anaerobic glucose metabolism. In hypoxia, insulin resistance blunted HIF1α activation and downstream signaling, but this was reversed by molidustat. In T2D rats, oral treatment with molidustat rescued the cardiac metabolic dysfunction caused by T2D, promoting glucose metabolism and mitochondrial function, while suppressing fatty acid oxidation and lipid accumulation. This resulted in beneficial effects on post-ischemic cardiac function, with the impaired contractile recovery in T2D heart reversed by molidustat treatment. In conclusion, pharmacological HIF1α stabilization can overcome the blunted hypoxic response induced by insulin resistance. In vivo this corrected the abnormal metabolic phenotype and impaired post-ischemic recovery of the diabetic heart. Therefore, molidustat may be an effective compound to further explore the clinical translatability of HIF1α activation in the diabetic heart.
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Affiliation(s)
| | - Ujang Purnama
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, U.K
| | - Kaitlyn M J H Dennis
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, U.K
| | | | - Marcos Castro-Guarda
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, U.K
| | - Emmanuelle Massourides
- Centre d'Etude des Cellules Souches/I-Stem, INSERM UMR 861, AFM-Téléthon, Corbeil-Essonnes, France
| | - Damian J Tyler
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, U.K
| | - Carolyn A Carr
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, U.K
| | - Lisa C Heather
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, U.K.
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Su Z, Liu Y, Zhang H. Adaptive Cardiac Metabolism Under Chronic Hypoxia: Mechanism and Clinical Implications. Front Cell Dev Biol 2021; 9:625524. [PMID: 33604337 PMCID: PMC7884626 DOI: 10.3389/fcell.2021.625524] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/11/2021] [Indexed: 11/29/2022] Open
Abstract
Chronic hypoxia is an essential component in many cardiac diseases. The heart consumes a substantial amount of energy and it is important to maintain the balance of energy supply and demand when oxygen is limited. Previous studies showed that the heart switches from fatty acid to glucose to maintain metabolic efficiency in the adaptation to chronic hypoxia. However, the underlying mechanism of this adaptive cardiac metabolism remains to be fully characterized. Moreover, how the altered cardiac metabolism affects the heart function in patients with chronic hypoxia has not been discussed in the current literature. In this review, we summarized new findings from animal and human studies to illustrate the mechanism underlying the adaptive cardiac metabolism under chronic hypoxia. Clinical focus is given to certain patients that are subject to the impact of chronic hypoxia, and potential treatment strategies that modulate cardiac metabolism and may improve the heart function in these patients are also summarized.
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Affiliation(s)
- Zhanhao Su
- State Key Laboratory of Cardiovascular Disease, National Center for Cardiovascular Diseases, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yiwei Liu
- Heart center and Shanghai Institute of Pediatric Congenital Heart Disease, Shanghai Children's Medical Center, National Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hao Zhang
- Heart center and Shanghai Institute of Pediatric Congenital Heart Disease, Shanghai Children's Medical Center, National Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China
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Watson WD, Timm KN, Lewis AJ, Miller JJJ, Emmanuel Y, Clarke K, Neubauer S, Tyler DJ, Rider OJ. Nicotinic acid receptor agonists impair myocardial contractility by energy starvation. FASEB J 2020; 34:14878-14891. [PMID: 32954525 DOI: 10.1096/fj.202000084rr] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 08/08/2020] [Accepted: 08/25/2020] [Indexed: 11/11/2022]
Abstract
Nicotinic acid receptor agonists have previously been shown to cause acute reductions in cardiac contractility. We sought to uncover the changes in cardiac metabolism underlying these alterations in function. In nine humans, we recorded cardiac energetics and function before and after a single oral dose of nicotinic acid using cardiac MRI to demonstrate contractile function and Phosphorus-31 (31 P) magnetic resonance spectroscopy to demonstrate myocardial energetics. Nicotinic Acid 400 mg lowered ejection fraction by 4% (64 ± 8% to 60 ± 7%, P = .03), and was accompanied by a fall in phosphocreatine/ATP ratio by 0.4 (2.2 ± 0.4 to 1.8 ± 0.1, P = .04). In four groups of eight Wistar rats, we used pyruvate dehydrogenase (PDH) flux studies to demonstrate changes in carbohydrate metabolism induced by the nicotinic acid receptor agonist, Acipimox, using hyperpolarized Carbon-13 (13 C) magnetic resonance spectroscopy. In rats which had been starved overnight, Acipimox caused a fall in ejection fraction by 7.8% (67.5 ± 8.9 to 60 ± 3.1, P = .03) and a nearly threefold rise in flux through PDH (from 0.182 ± 0.114 to 0.486 ± 0.139, P = .002), though this rise did not match pyruvate dehydrogenase flux observed in rats fed carbohydrate rich chow (0.726 ± 0.201). In fed rats, Acipimox decreased pyruvate dehydrogenase flux (to 0.512 ± 0.13, P = .04). Concentration of plasma insulin fell by two-thirds in fed rats administered Acipimox (from 1695 ± 891 ng/L to 550 ± 222 ng/L, P = .005) in spite of glucose concentrations remaining the same. In conclusion, we demonstrate that nicotinic acid receptor agonists impair cardiac contractility associated with a decline in cardiac energetics and show that the mechanism is likely a combination of reduced fatty acid availability and a failure to upregulate carbohydrate metabolism, essentially starving the heart of fuel.
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Affiliation(s)
- William D Watson
- Department of Cardiovascular Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK
| | - Kerstin N Timm
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Andrew J Lewis
- Department of Cardiovascular Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK
| | - Jack J J Miller
- Department of Cardiovascular Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
- Department of Physics, University of Oxford, Oxford, UK
| | - Yaso Emmanuel
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Kieran Clarke
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Stefan Neubauer
- Department of Cardiovascular Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK
| | - Damian J Tyler
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - Oliver J Rider
- Department of Cardiovascular Medicine, Oxford Centre for Clinical Magnetic Resonance Research, University of Oxford, Oxford, UK
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7
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Watson WD, Miller JJJ, Lewis A, Neubauer S, Tyler D, Rider OJ, Valkovič L. Use of cardiac magnetic resonance to detect changes in metabolism in heart failure. Cardiovasc Diagn Ther 2020; 10:583-597. [PMID: 32695639 DOI: 10.21037/cdt.2019.12.13] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The heart has a massive adenosine triphosphate (ATP) requirement, produced from the oxidation of metabolic substrates such as fat and glucose. Magnetic resonance spectroscopy offers a unique opportunity to probe this biochemistry: 31Phosphorus spectroscopy can demonstrate the production of ATP and quantify levels of the transport molecule phosphocreatine while 13Carbon spectroscopy can demonstrate the metabolic fates of glucose in real time. These techniques allow the metabolic deficits in heart failure to be interrogated and can be a potential future clinical tool.
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Affiliation(s)
- William D Watson
- Oxford Centre for Clinical Magnetic Resonance Research, Clarendon Laboratory, University of Oxford, Oxford, UK
| | - Jack J J Miller
- Oxford Centre for Clinical Magnetic Resonance Research, Clarendon Laboratory, University of Oxford, Oxford, UK.,Department of Physiology, Anatomy and Genetics, Clarendon Laboratory, University of Oxford, Oxford, UK.,Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, UK
| | - Andrew Lewis
- Oxford Centre for Clinical Magnetic Resonance Research, Clarendon Laboratory, University of Oxford, Oxford, UK
| | - Stefan Neubauer
- Oxford Centre for Clinical Magnetic Resonance Research, Clarendon Laboratory, University of Oxford, Oxford, UK
| | - Damian Tyler
- Oxford Centre for Clinical Magnetic Resonance Research, Clarendon Laboratory, University of Oxford, Oxford, UK.,Department of Physiology, Anatomy and Genetics, Clarendon Laboratory, University of Oxford, Oxford, UK
| | - Oliver J Rider
- Oxford Centre for Clinical Magnetic Resonance Research, Clarendon Laboratory, University of Oxford, Oxford, UK
| | - Ladislav Valkovič
- Oxford Centre for Clinical Magnetic Resonance Research, Clarendon Laboratory, University of Oxford, Oxford, UK.,Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
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