1
|
Martsenyuk V, Soldatkin O, Klos-Witkowska A, Sverstiuk A, Berketa K. Operational stability study of lactate biosensors: modeling, parameter identification, and stability analysis. Front Bioeng Biotechnol 2024; 12:1385459. [PMID: 39091973 PMCID: PMC11292224 DOI: 10.3389/fbioe.2024.1385459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 06/03/2024] [Indexed: 08/04/2024] Open
Abstract
Introduction This paper investigates the operational stability of lactate biosensors, crucial devices in various biomedical and biotechnological applications. We detail the construction of an amperometric transducer tailored for lactate measurement and outline the experimental setup used for empirical validation. Methods The modeling framework incorporates Brown and Michaelis-Menten kinetics, integrating both distributed and discrete delays to capture the intricate dynamics of lactate sensing. To ascertain model parameters, we propose a nonlinear optimization method, leveraging initial approximations from the Brown model's delay values for the subsequent model with discrete delays. Results Stability analysis forms a cornerstone of our investigation, centering on linearization around equilibrium states and scrutinizing the real parts of quasi-polynomials. Notably, our findings reveal that the discrete delay model manifests marginal stability, occupying a delicate balance between asymptotic stability and instability. We introduce criteria for verifying marginal stability based on characteristic quasi-polynomial roots, offering practical insights into system behavior. Discussion Qalitative examination of the model elucidates the influence of delay on dynamic behavior. We observe a transition from stable focus to limit cycle and period-doubling phenomena with increasing delay values, as evidenced by phase plots and bifurcation diagrams employing Poincaré sections. Additionally, we identify limitations in model applicability, notably the loss of solution positivity with growing delays, underscoring the necessity for cautious interpretation when employing delayed exponential function formulations. This comprehensive study provides valuable insights into the design and operational characteristics of lactate biosensors, offering a robust framework for understanding and optimizing their performance in diverse settings.
Collapse
Affiliation(s)
- Vasyl Martsenyuk
- Department of Computer Science and Automatics, University of Bielsko-Biala, Bielsko-Biala, Poland
| | - Oleksandr Soldatkin
- Department of Biomolecular Electronics, Institute of Molecular Biology and Genetics of NASU, Kyiv, Ukraine
| | | | - Andriy Sverstiuk
- Department of Medical Informatics, Ivan Horbachevsky Ternopil National Medical University of the Ministry of Health of Ukraine, Ternopil, Ukraine
- Department of Computer Science, Ternopil Ivan Puluj National Technical University, Ternopil, Ukraine
| | - Ksenya Berketa
- Department of Biomolecular Electronics, Institute of Molecular Biology and Genetics of NASU, Kyiv, Ukraine
| |
Collapse
|
2
|
Lai YC, Hsieh CY, Juan YH, Lu KY, Lee HJ, Ng SH, Wan YL, Lin G. Hyperpolarized Carbon-13 Magnetic Resonance Imaging: Technical Considerations and Clinical Applications. Korean J Radiol 2024; 25:459-472. [PMID: 38685736 PMCID: PMC11058429 DOI: 10.3348/kjr.2024.0069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 02/17/2024] [Accepted: 02/27/2024] [Indexed: 05/02/2024] Open
Abstract
Hyperpolarized (HP) carbon-13 (13C) MRI represents an innovative approach for noninvasive, real-time assessment of dynamic metabolic flux, with potential integration into routine clinical MRI. The use of [1-13C]pyruvate as a probe and its conversion to [1-13C]lactate constitute an extensively explored metabolic pathway. This review comprehensively outlines the establishment of HP 13C-MRI, covering multidisciplinary team collaboration, hardware prerequisites, probe preparation, hyperpolarization techniques, imaging acquisition, and data analysis. This article discusses the clinical applications of HP 13C-MRI across various anatomical domains, including the brain, heart, skeletal muscle, breast, liver, kidney, pancreas, and prostate. Each section highlights the specific applications and findings pertinent to these regions, emphasizing the potential versatility of HP 13C-MRI in diverse clinical contexts. This review serves as a comprehensive update, bridging technical aspects with clinical applications and offering insights into the ongoing advancements in HP 13C-MRI.
Collapse
Affiliation(s)
- Ying-Chieh Lai
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan
- Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Ching-Yi Hsieh
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan
- Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Research Center for Radiation Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Yu-Hsiang Juan
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Kuan-Ying Lu
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Hsien-Ju Lee
- Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
| | - Shu-Hang Ng
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Yung-Liang Wan
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan
| | - Gigin Lin
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Department of Medical Imaging and Radiological Sciences, Chang Gung University, Taoyuan, Taiwan
- Clinical Metabolomics Core Laboratory, Chang Gung Memorial Hospital at Linkou, Taoyuan, Taiwan
- Research Center for Radiation Medicine, Chang Gung University, Taoyuan, Taiwan.
| |
Collapse
|
3
|
Kamson DO, Chinnasamy V, Grossman SA, Bettegowda C, Barker PB, Stacpoole PW, Oeltzschner G. In-vivo magnetic resonance spectroscopy of lactate as a non-invasive biomarker of dichloroacetate activity in cancer and non-cancer central nervous system disorders. Front Oncol 2023; 13:1077461. [PMID: 37007074 PMCID: PMC10063958 DOI: 10.3389/fonc.2023.1077461] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/22/2023] [Indexed: 03/19/2023] Open
Abstract
The adverse effects of lactic acidosis in the cancer microenvironment have been increasingly recognized. Dichloroacetate (DCA) is an orally bioavailable, blood brain barrier penetrable drug that has been extensively studied in the treatment of mitochondrial neurologic conditions to reduce lactate production. Due to its effect reversing aerobic glycolysis (i.e., Warburg-effect) and thus lactic acidosis, DCA became a drug of interest in cancer as well. Magnetic resonance spectroscopy (MRS) is a well-established, non-invasive technique that allows detection of prominent metabolic changes, such as shifts in lactate or glutamate levels. Thus, MRS is a potential radiographic biomarker to allow spatial and temporal mapping of DCA treatment. In this systematic literature review, we gathered the available evidence on the use of various MRS techniques to track metabolic changes after DCA administration in neurologic and oncologic disorders. We included in vitro, animal, and human studies. Evidence confirms that DCA has substantial effects on lactate and glutamate levels in neurologic and oncologic disease, which are detectable by both experimental and routine clinical MRS approaches. Data from mitochondrial diseases show slower lactate changes in the central nervous system (CNS) that correlate better with clinical function compared to blood. This difference is most striking in focal impairments of lactate metabolism suggesting that MRS might provide data not captured by solely monitoring blood. In summary, our findings corroborate the feasibility of MRS as a pharmacokinetic/pharmacodynamic biomarker of DCA delivery in the CNS, that is ready to be integrated into currently ongoing and future human clinical trials using DCA.
Collapse
Affiliation(s)
- David O. Kamson
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, United States
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
- *Correspondence: David O. Kamson, ; Georg Oeltzschner,
| | - Viveka Chinnasamy
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, United States
| | - Stuart A. Grossman
- The Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD, United States
| | - Chetan Bettegowda
- Department of Neurosurgery, Johns Hopkins University, Baltimore, MD, United States
| | - Peter B. Barker
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
| | - Peter W. Stacpoole
- Departments of Medicine and Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL, United States
| | - Georg Oeltzschner
- Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, MD, United States
- *Correspondence: David O. Kamson, ; Georg Oeltzschner,
| |
Collapse
|
4
|
Stevanato G, Ding Y, Mamone S, Jagtap AP, Korchak S, Glöggler S. Real-Time Pyruvate Chemical Conversion Monitoring Enabled by PHIP. J Am Chem Soc 2023; 145:5864-5871. [PMID: 36857108 PMCID: PMC10021011 DOI: 10.1021/jacs.2c13198] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
In recent years, parahydrogen-induced polarization side arm hydrogenation (PHIP-SAH) has been applied to hyperpolarize [1-13C]pyruvate and map its metabolic conversion to [1-13C]lactate in cancer cells. Developing on our recent MINERVA pulse sequence protocol, in which we have achieved 27% [1-13C]pyruvate carbon polarization, we demonstrate the hyperpolarization of [1,2-13C]pyruvate (∼7% polarization on each 13C spin) via PHIP-SAH. By altering a single parameter in the pulse sequence, MINERVA enables the signal enhancement of C1 and/or C2 in [1,2-13C]pyruvate with the opposite phase, which allows for the simultaneous monitoring of different chemical reactions with enhanced spectral contrast or for the same reaction via different carbon sites. We first demonstrate the ability to monitor the same enzymatic pyruvate to lactate conversion at 7T in an aqueous solution, in vitro, and in-cell (HeLa cells) via different carbon sites. In a second set of experiments, we use the C1 and C2 carbon positions as spectral probes for simultaneous chemical reactions: the production of acetate, carbon dioxide, bicarbonate, and carbonate by reacting [1,2-13C]pyruvate with H2O2 at a high temperature (55 °C). Importantly, we detect and characterize the intermediate 2-hydroperoxy-2-hydroxypropanoate in real time and at high temperature.
Collapse
Affiliation(s)
- Gabriele Stevanato
- NMR Signal Enhancement Group, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration of the University Medical Center Göttingen, Von-Siebold-Street 3A, 37075 Göttingen, Germany
| | - Yonghong Ding
- NMR Signal Enhancement Group, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration of the University Medical Center Göttingen, Von-Siebold-Street 3A, 37075 Göttingen, Germany
| | - Salvatore Mamone
- NMR Signal Enhancement Group, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration of the University Medical Center Göttingen, Von-Siebold-Street 3A, 37075 Göttingen, Germany
| | - Anil P Jagtap
- NMR Signal Enhancement Group, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration of the University Medical Center Göttingen, Von-Siebold-Street 3A, 37075 Göttingen, Germany
| | - Sergey Korchak
- NMR Signal Enhancement Group, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration of the University Medical Center Göttingen, Von-Siebold-Street 3A, 37075 Göttingen, Germany
| | - Stefan Glöggler
- NMR Signal Enhancement Group, Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Göttingen, Germany.,Center for Biostructural Imaging of Neurodegeneration of the University Medical Center Göttingen, Von-Siebold-Street 3A, 37075 Göttingen, Germany
| |
Collapse
|
5
|
Chowdhury R, Papoutsaki MV, Müller CA, Smith L, Gong F, Bullock M, Rogers H, Mathew M, Syer T, Singh S, Retter A, Caselton L, Ryu J, Oliver-Taylor A, Golay X, Bainbridge A, Gadian DG, Punwani S. A reproducible dynamic phantom for sequence testing in hyperpolarised 13C-magnetic resonance. Br J Radiol 2022; 95:20210770. [PMID: 35230136 PMCID: PMC10996405 DOI: 10.1259/bjr.20210770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 02/10/2022] [Accepted: 02/28/2022] [Indexed: 11/05/2022] Open
Abstract
OBJECTIVE To develop a phantom system which can be integrated with an automated injection system, eliminating the experimental variability that arises with manual injection; for the purposes of pulse sequence testing and metric derivation in hyperpolarised 13C-MR. METHODS The custom dynamic phantom was machined from Ultem and filled with a nicotinamide adenine dinucleotide and lactate dehydrogenase mixture dissolved in phosphate buffered saline. Hyperpolarised [1-13C]-pyruvate was then injected into the phantom (n = 8) via an automated syringe pump and the conversion of pyruvate to lactate monitored through a 13C imaging sequence. RESULTS The phantom showed low coefficient of variation for the lactate to pyruvate peak signal heights (11.6%) and dynamic area-under curve ratios (11.0%). The variance for the lactate dehydrogenase enzyme rate constant (kP) was also seen to be low at 15.6%. CONCLUSION The dynamic phantom demonstrates high reproducibility for quantification of 13C-hyperpolarised MR-derived metrics. Establishing such a phantom is needed to facilitate development of hyperpolarsed 13C-MR pulse sequenced; and moreover, to enable multisite hyperpolarised 13C-MR clinical trials where assessment of metric variability across sites is critical. ADVANCES IN KNOWLEDGE The dynamic phantom developed during the course of this study will be a useful tool in testing new pulse sequences and standardisation in future hyperpolarised work.
Collapse
Affiliation(s)
- Rafat Chowdhury
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | | | - Christoph A Müller
- Department of Radiology, Medical Physics, Medical Center
– University of Freiburg, Faculty of Medicine, University of
Freiburg, Freiburg,
Germany
- German Cancer Consortium (DKTK), partner site Freiburg, German
Cancer Research Center (DKFZ),
Heidelberg, Germany
| | | | - Fiona Gong
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | - Max Bullock
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | - Harriet Rogers
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | - Manju Mathew
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | - Tom Syer
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | - Saurabh Singh
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | - Adam Retter
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | - Lucy Caselton
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | - Jung Ryu
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
| | | | - Xavier Golay
- Gold Standard Phantoms Limited,
London, UK
- Department of Brain Repair and Rehabilitation, Institute of
Neurology, Queen’s Square, University College
London, London,
UK
| | - Alan Bainbridge
- Department of Medical Physics and Biomedical Engineering,
University College London Hospitals,
London, UK
| | - David G Gadian
- UCL Great Ormond Street Institute of Child
Health, London, UK
| | - Shonit Punwani
- Centre for Medical Imaging, Division of Medicine, University
College London, London,
UK
- Department of Radiology, University College London Hospitals
NHS Foundation Trust, London,
UK
| |
Collapse
|
6
|
Ragavan M, McLeod MA, Rushin A, Merritt ME. Detecting de novo Hepatic Ketogenesis Using Hyperpolarized [2- 13C] Pyruvate. Front Physiol 2022; 13:832403. [PMID: 35197867 PMCID: PMC8859440 DOI: 10.3389/fphys.2022.832403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 01/14/2022] [Indexed: 11/28/2022] Open
Abstract
The role of ketones in metabolic health has progressed over the past two decades, moving from what was perceived as a simple byproduct of fatty acid oxidation to a central player in a multiplicity of disease states. Previous work with hyperpolarized (HP) 13C has shown that ketone production can be detected when using precursors that labeled acetyl-CoA at the C1 position, often in tissues that are not normally recognized as ketogenic. Here, we assay metabolism of HP [2-13C]pyruvate in the perfused mouse liver, a classic metabolic testbed where nutritional conditions can be precisely controlled. Livers perfused with long-chain fatty acids or the medium-chain fatty acid octanoate showed no evidence of ketogenesis in the 13C spectrum. In contrast, addition of dichloroacetate, a potent inhibitor of pyruvate dehydrogenase kinase, resulted in significant production of both acetoacetate and 3-hydroxybutyrate from the pyruvate precursor. This result indicates that ketones are readily produced from carbohydrates, but only in the case where pyruvate dehydrogenase activity is upregulated.
Collapse
Affiliation(s)
| | | | | | - Matthew E. Merritt
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, FL, United States
| |
Collapse
|
7
|
Stewart NJ, Sato T, Takeda N, Hirata H, Matsumoto S. Hyperpolarized 13C Magnetic Resonance Imaging as a Tool for Imaging Tissue Redox State, Oxidative Stress, Inflammation, and Cellular Metabolism. Antioxid Redox Signal 2022; 36:81-94. [PMID: 34218688 PMCID: PMC8792501 DOI: 10.1089/ars.2021.0139] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Significance: Magnetic resonance imaging (MRI) with hyperpolarized (HP) 13C-labeled redox-sensitive metabolic tracers can provide noninvasive functional imaging biomarkers, reflecting tissue redox state, oxidative stress, and inflammation, among others. The capability to use endogenous metabolites as 13C-enriched imaging tracers without structural modification makes HP 13C MRI a promising tool to evaluate redox state in patients with various diseases. Recent Advances: Recent studies have demonstrated the feasibility of in vivo metabolic imaging of 13C-labeled tracers polarized by parahydrogen-induced polarization techniques, which offer a cost-effective alternative to the more widely used dissolution dynamic nuclear polarization-based hyperpolarizers. Critical Issues: Although the fluxes of many metabolic pathways reflect the change in tissue redox state, they are not functionally specific. In the present review, we summarize recent challenges in the development of specific 13C metabolic tracers for biomarkers of redox state, including that for detecting reactive oxygen species. Future Directions: Applications of HP 13C metabolic MRI to evaluate redox state have only just begun to be investigated. The possibility to gain a comprehensive understanding of the correlations between tissue redox potential and metabolism under different pathological conditions by using HP 13C MRI is promoting its interest in the clinical arena, along with its noninvasive biomarkers to evaluate the extent of disease and treatment response.
Collapse
Affiliation(s)
- Neil J Stewart
- Division of Bioengineering & Bioinformatics, Graduate School of Information Science & Technology, Hokkaido University, Sapporo, Japan.,POLARIS, Imaging Sciences, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Tatsuyuki Sato
- Division of Cardiology and Metabolism Center for Molecular Medicine, Jichi Medical University, Shimotsuke-shi, Japan.,Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Norihiko Takeda
- Division of Cardiology and Metabolism Center for Molecular Medicine, Jichi Medical University, Shimotsuke-shi, Japan
| | - Hiroshi Hirata
- Division of Bioengineering & Bioinformatics, Graduate School of Information Science & Technology, Hokkaido University, Sapporo, Japan
| | - Shingo Matsumoto
- Division of Bioengineering & Bioinformatics, Graduate School of Information Science & Technology, Hokkaido University, Sapporo, Japan
| |
Collapse
|
8
|
Hong D, Batsios G, Viswanath P, Gillespie AM, Vaidya M, Larson PEZ, Ronen SM. Acquisition and quantification pipeline for in vivo hyperpolarized 13 C MR spectroscopy. Magn Reson Med 2021; 87:1673-1687. [PMID: 34775639 DOI: 10.1002/mrm.29081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 10/16/2021] [Accepted: 10/22/2021] [Indexed: 11/08/2022]
Abstract
PURPOSE The goal of this study was to combine a specialized acquisition method with a new quantification pipeline to accurately and efficiently probe the metabolism of hyperpolarized 13 C-labeled compounds in vivo. In this study, we tested our approach on [2-13 C]pyruvate and [1-13 C]α-ketoglutarate data in rat orthotopic brain tumor models at 3T. METHODS We used a multiband metabolite-specific radiofrequency (RF) excitation in combination with a variable flip angle scheme to minimize substrate polarization loss and measure fast metabolic processes. We then applied spectral-temporal denoising using singular value decomposition to enhance spectral quality. This was combined with LCModel-based automatic 13 C spectral fitting and flip angle correction to separate overlapping signals and rapidly quantify the different metabolites. RESULTS Denoising improved the metabolite signal-to-noise ratio (SNR) by approximately 5. It also improved the accuracy of metabolite quantification as evidenced by a significant reduction of the Cramer Rao lower bounds. Furthermore, the use of the automated and user-independent LCModel-based quantification approach could be performed rapidly, with the kinetic quantification of eight metabolite peaks in a 12-spectrum array achieved in less than 1 minute. CONCLUSION The specialized acquisition method combined with denoising and a new quantification pipeline using LCModel for the first time for hyperpolarized 13 C data enhanced our ability to monitor the metabolism of [2-13 C]pyruvate and [1-13 C]α-ketoglutarate in rat orthotopic brain tumor models in vivo. This approach could be broadly applicable to other hyperpolarized agents both preclinically and in the clinical setting.
Collapse
Affiliation(s)
- Donghyun Hong
- Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Georgios Batsios
- Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Pavithra Viswanath
- Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Anne Marie Gillespie
- Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Manushka Vaidya
- Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Peder E Z Larson
- Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| | - Sabrina M Ronen
- Department of Radiology & Biomedical Imaging, University of California San Francisco, San Francisco, California, USA
| |
Collapse
|
9
|
Macdonald EB, Begovatz P, Barton GP, Erickson-Bhatt S, Inman DR, Cox BL, Eliceiri KW, Strigel RM, Ponik SM, Fain SB. Hyperpolarized 13C Magnetic Resonance Spectroscopic Imaging of Pyruvate Metabolism in Murine Breast Cancer Models of Different Metastatic Potential. Metabolites 2021; 11:metabo11050274. [PMID: 33925445 PMCID: PMC8145849 DOI: 10.3390/metabo11050274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/05/2021] [Accepted: 04/21/2021] [Indexed: 12/18/2022] Open
Abstract
This study uses dynamic hyperpolarized [1-13C]pyruvate magnetic resonance spectroscopic imaging (MRSI) to estimate differences in glycolytic metabolism between highly metastatic (4T1, n = 7) and metastatically dormant (4T07, n = 7) murine breast cancer models. The apparent conversion rate of pyruvate-to-lactate (kPL) and lactate-to-pyruvate area-under-the-curve ratio (AUCL/P) were estimated from the metabolite images and compared with biochemical metabolic measures and immunohistochemistry (IHC). A non-significant trend of increasing kPL (p = 0.17) and AUCL/P (p = 0.11) from 4T07 to 4T1 tumors was observed. No significant differences in tumor IHC lactate dehydrogenase-A (LDHA), monocarboxylate transporter-1 (MCT1), cluster of differentiation 31 (CD31), and hypoxia inducible factor-α (HIF-1α), tumor lactate-dehydrogenase (LDH) activity, or blood lactate or glucose levels were found between the two tumor lines. However, AUCL/P was significantly correlated with tumor LDH activity (ρspearman = 0.621, p = 0.027) and blood glucose levels (ρspearman = −0.474, p = 0.042). kPL displayed a similar, non-significant trend for LDH activity (ρspearman = 0.480, p = 0.114) and blood glucose levels (ρspearman = −0.414, p = 0.088). Neither kPL nor AUCL/P were significantly correlated with blood lactate levels or tumor LDHA or MCT1. The significant positive correlation between AUCL/P and tumor LDH activity indicates the potential of AUCL/P as a biomarker of glycolytic metabolism in breast cancer models. However, the lack of a significant difference between in vivo tumor metabolism for the two models suggest similar pyruvate-to-lactate conversion despite differing metastatic potential.
Collapse
Affiliation(s)
- Erin B. Macdonald
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (E.B.M.); (P.B.); (G.P.B.); (B.L.C.); (K.W.E.); (R.M.S.)
| | - Paul Begovatz
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (E.B.M.); (P.B.); (G.P.B.); (B.L.C.); (K.W.E.); (R.M.S.)
| | - Gregory P. Barton
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (E.B.M.); (P.B.); (G.P.B.); (B.L.C.); (K.W.E.); (R.M.S.)
| | - Sarah Erickson-Bhatt
- Morgridge Institute for Research, 330 N. Orchard St., Madison, WI 53715, USA;
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (D.R.I.); (S.M.P.)
| | - David R. Inman
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (D.R.I.); (S.M.P.)
| | - Benjamin L. Cox
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (E.B.M.); (P.B.); (G.P.B.); (B.L.C.); (K.W.E.); (R.M.S.)
- Morgridge Institute for Research, 330 N. Orchard St., Madison, WI 53715, USA;
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Kevin W. Eliceiri
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (E.B.M.); (P.B.); (G.P.B.); (B.L.C.); (K.W.E.); (R.M.S.)
- Morgridge Institute for Research, 330 N. Orchard St., Madison, WI 53715, USA;
- Laboratory for Optical and Computational Instrumentation, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Biomedical Engineering, University of Wisconsin-Madison, 1415 Engineering Dr., Madison, WI 53706, USA
- Carbone Cancer Center, University of Wisconsin-Madison, 600 Highland Ave., Madison, WI 53705, USA
| | - Roberta M. Strigel
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (E.B.M.); (P.B.); (G.P.B.); (B.L.C.); (K.W.E.); (R.M.S.)
- Carbone Cancer Center, University of Wisconsin-Madison, 600 Highland Ave., Madison, WI 53705, USA
- Department of Radiology, University of Wisconsin-Madison, 600 Highland Ave., Madison, WI 53792, USA
| | - Suzanne M. Ponik
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (D.R.I.); (S.M.P.)
- Carbone Cancer Center, University of Wisconsin-Madison, 600 Highland Ave., Madison, WI 53705, USA
| | - Sean B. Fain
- Department of Medical Physics, University of Wisconsin-Madison, 1111 Highland Ave., Madison, WI 53705, USA; (E.B.M.); (P.B.); (G.P.B.); (B.L.C.); (K.W.E.); (R.M.S.)
- Department of Biomedical Engineering, University of Wisconsin-Madison, 1415 Engineering Dr., Madison, WI 53706, USA
- Carbone Cancer Center, University of Wisconsin-Madison, 600 Highland Ave., Madison, WI 53705, USA
- Department of Radiology, University of Wisconsin-Madison, 600 Highland Ave., Madison, WI 53792, USA
- Correspondence: ; Tel.: +1-608-263-0090
| |
Collapse
|
10
|
Stewart NJ, Matsumoto S. Biomedical Applications of the Dynamic Nuclear Polarization and Parahydrogen Induced Polarization Techniques for Hyperpolarized 13C MR Imaging. Magn Reson Med Sci 2021; 20:1-17. [PMID: 31902907 PMCID: PMC7952198 DOI: 10.2463/mrms.rev.2019-0094] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 11/04/2019] [Indexed: 12/17/2022] Open
Abstract
Since the first pioneering report of hyperpolarized [1-13C]pyruvate magnetic resonance imaging (MRI) of the Warburg effect in prostate cancer patients, clinical dissemination of the technique has been rapid; close to 10 sites worldwide now possess a polarizer fit for the clinic, and more than 30 clinical trials, predominantly for oncological applications, are already registered on the US and European clinical trials databases. Hyperpolarized 13C probes to study pathophysiological processes beyond the Warburg effect, including tricarboxylic acid cycle metabolism, intra-cellular pH and cellular necrosis have also been demonstrated in the preclinical arena and are pending clinical translation, and the simultaneous injection of multiple co-polarized agents is opening the door to high-sensitivity, multi-functional molecular MRI with a single dose. Here, we review the biomedical applications to date of the two polarization methods that have been used for in vivo hyperpolarized 13C molecular MRI; namely, dissolution dynamic nuclear polarization and parahydrogen-induced polarization. The basic concept of hyperpolarization and the fundamental theory underpinning these two key 13C hyperpolarization methods, along with recent technological advances that have facilitated biomedical realization, are also covered.
Collapse
Affiliation(s)
- Neil J. Stewart
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, Hokkaido, Japan
| | - Shingo Matsumoto
- Division of Bioengineering and Bioinformatics, Graduate School of Information Science and Technology, Hokkaido University, Hokkaido, Japan
| |
Collapse
|
11
|
von Morze C, Engelbach JA, Reed GD, Chen AP, Quirk JD, Blazey T, Mahar R, Malloy CR, Garbow JR, Merritt ME. 15 N-carnitine, a novel endogenous hyperpolarized MRI probe with long signal lifetime. Magn Reson Med 2020; 85:1814-1820. [PMID: 33179825 DOI: 10.1002/mrm.28578] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 10/05/2020] [Accepted: 10/09/2020] [Indexed: 12/22/2022]
Abstract
PURPOSE The purpose of this study was to investigate hyperpolarization and in vivo imaging of [15 N]carnitine, a novel endogenous MRI probe with long signal lifetime. METHODS L-[15 N]carnitine-d9 was hyperpolarized by the method of dynamic nuclear polarization followed by rapid dissolution. The T1 signal lifetimes were estimated in aqueous solution and in vivo following intravenous injection in rats, using a custom-built dual-tuned 15 N/1 H RF coil at 4.7 T. 15 N chemical shift imaging and 15 N fast spin-echo images of rat abdomen were acquired 3 minutes after [15 N]carnitine injection. RESULTS Estimated T1 times of [15 N]carnitine at 4.7 T were 210 seconds (in H2 O) and 160 seconds (in vivo), with an estimated polarization level of 10%. Remarkably, the [15 N]carnitine coherence was detectable in rat abdomen for 5 minutes after injection for the nonlocalized acquisition. No downstream metabolites were detected on localized or nonlocalized 15 N spectra. Diffuse liver enhancement was detected on 15 N fast spin-echo imaging 3 minutes after injection, with mean hepatic SNR of 18 ± 5 at a spatial resolution of 4 × 4 mm. CONCLUSION This study showed the feasibility of hyperpolarizing and imaging the biodistribution of HP [15 N]carnitine.
Collapse
Affiliation(s)
- Cornelius von Morze
- Mallinckrodt Institute of Radiology, Washington University, St Louis, Missouri, USA
| | - John A Engelbach
- Mallinckrodt Institute of Radiology, Washington University, St Louis, Missouri, USA
| | | | | | - James D Quirk
- Mallinckrodt Institute of Radiology, Washington University, St Louis, Missouri, USA
| | - Tyler Blazey
- Mallinckrodt Institute of Radiology, Washington University, St Louis, Missouri, USA
| | - Rohit Mahar
- Department of Biochemistry, University of Florida, Gainesville, Florida, USA
| | - Craig R Malloy
- Advanced Imaging Research Center, University of Texas, Southwestern, Dallas, Texas, USA
| | - Joel R Garbow
- Mallinckrodt Institute of Radiology, Washington University, St Louis, Missouri, USA
| | - Matthew E Merritt
- Department of Biochemistry, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
12
|
Pedersen M, Ursprung S, Jensen JD, Jespersen B, Gallagher F, Laustsen C. Hyperpolarised 13C-MRI metabolic and functional imaging: an emerging renal MR diagnostic modality. MAGMA (NEW YORK, N.Y.) 2020; 33:23-32. [PMID: 31782036 DOI: 10.1007/s10334-019-00801-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 10/21/2019] [Accepted: 11/12/2019] [Indexed: 12/11/2022]
Abstract
Magnetic resonance imaging (MRI) is a well-established modality for assessing renal morphology and function, as well as changes that occur during disease. However, the significant metabolic changes associated with renal disease are more challenging to assess with MRI. Hyperpolarized carbon-13 MRI is an emerging technique which provides an opportunity to probe metabolic alterations at high sensitivity by providing an increase in the signal-to-noise ratio of 20,000-fold or more. This review will highlight the current status of hyperpolarised 13C-MRI and its translation into the clinic and how it compares to metabolic measurements provided by competing technologies such as positron emission tomography (PET).
Collapse
Affiliation(s)
| | - Stephan Ursprung
- Department of Radiology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Jens Dam Jensen
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Bente Jespersen
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Ferdia Gallagher
- Department of Radiology, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Christoffer Laustsen
- MR Research Centre, Department of Clinical Medicine, Aarhus University Hospital, Palle Juul Jensens Boulevard, 8200, Aarhus N, Denmark.
| |
Collapse
|
13
|
von Morze C, Merritt ME. Cancer in the crosshairs: targeting cancer metabolism with hyperpolarized carbon-13 MRI technology. NMR IN BIOMEDICINE 2019; 32:e3937. [PMID: 29870085 PMCID: PMC6281789 DOI: 10.1002/nbm.3937] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 04/03/2018] [Accepted: 04/07/2018] [Indexed: 05/07/2023]
Abstract
Magnetic resonance (MR)-based hyperpolarized (HP) 13 C metabolic imaging is under active pursuit as a new clinical diagnostic method for cancer detection, grading, and monitoring of therapeutic response. Following the tremendous success of metabolic imaging by positron emission tomography, which already plays major roles in clinical oncology, the added value of HP 13 C MRI is emerging. Aberrant glycolysis and central carbon metabolism is a hallmark of many forms of cancer. The chemical transformations associated with these pathways produce metabolites ranging in general from three to six carbons, and are dependent on the redox state and energy charge of the tissue. The significant changes in chemistry associated with flux through these pathways imply that HP imaging can take advantage of the underlying chemical shift information encoded into an MR experiment to produce images of the injected substrate as well as its metabolites. However, imaging of HP metabolites poses unique constraints on pulse sequence design related to detection of X-nuclei, decay of the HP magnetization due to T1 , and the consumption of HP signal by the inspection pulses. Advancements in the field continue to depend critically on customization of MRI systems and pulse sequences for optimized detection of HP 13 C signals, focused largely on extracting the maximum amount of information during the short lifetime of the HP magnetization. From a clinical perspective, the success of HP 13 C MRI of cancer will largely depend upon the utility of HP pyruvate for the detection of lactate pools associated with the Warburg effect, though several other agents are also under investigation, with novel agents continually being formulated. In this review, the salient aspects of HP 13 C imaging will be highlighted, with an emphasis on both technological challenges and the biochemical aspects of HP experimental design.
Collapse
Affiliation(s)
- Cornelius von Morze
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Matthew E Merritt
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA
| |
Collapse
|
14
|
Steinhauser J, Wespi P, Kwiatkowski G, Kozerke S. Production of highly polarized [1- 13 C]acetate by rapid decarboxylation of [2- 13 C]pyruvate - application to hyperpolarized cardiac spectroscopy and imaging. Magn Reson Med 2019; 82:1140-1149. [PMID: 31045272 DOI: 10.1002/mrm.27782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/27/2019] [Accepted: 04/03/2019] [Indexed: 11/10/2022]
Abstract
PURPOSE The objective of the present work was to develop and implement an efficient approach to hyperpolarize [1-13 C]acetate and apply it to in vivo cardiac spectroscopy and imaging. METHODS Rapid hydrogen peroxide induced decarboxylation was used to convert hyperpolarized [2-13 C]pyruvate into highly polarized [1-13 C]acetate employing an additional step following rapid dissolution of [2-13 C]pyruvate in a home-built multi-sample dissolution dynamic nuclear polarization system. Phantom dissolution experiments were conducted to determine optimal parameters of the decarboxylation reaction, retaining polarization and T1 of [1-13 C]acetate. In vivo feasibility of detecting [1-13 C]acetate metabolism is demonstrated using slice-selective spectroscopy and multi-echo imaging of [1-13 C]acetate and [1-13 C]acetylcarnitine in the healthy rat heart. RESULTS The first in vivo signal was observed ~23 s after dissolution. At the corresponding time point in the phantom experiments, 97.9 ± 0.4% of [2-13 C]pyruvate were converted into [1-13 C]acetate by the decarboxylation reaction. T1 and polarization of [1-13 C]acetate was determined to be 29.7 ± 1.9% and a 47.7 ± 0.5 s. Polarization levels of [2-13 C]pyruvate and [1-13 C]acetate were not significantly different after transfer to the scanner. In vivo, [1-13 C]acetate and [1-13 C]acetylcarnitine could be detected using spectroscopy and imaging. CONCLUSION Decarboxylation of hyperpolarized [2-13 C]pyruvate enables the efficient production of highly polarized [1-13 C]acetate that is applicable to study short-chain fatty acid metabolism in the in vivo heart.
Collapse
Affiliation(s)
- Jonas Steinhauser
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Patrick Wespi
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Grzegorz Kwiatkowski
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| |
Collapse
|
15
|
Miller JJ, Ball DR, Lau AZ, Tyler DJ. Hyperpolarized ketone body metabolism in the rat heart. NMR IN BIOMEDICINE 2018; 31:e3912. [PMID: 29637642 PMCID: PMC6001529 DOI: 10.1002/nbm.3912] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 01/22/2018] [Accepted: 02/06/2018] [Indexed: 05/13/2023]
Abstract
The aim of this work was to investigate the use of 13 C-labelled acetoacetate and β-hydroxybutyrate as novel hyperpolarized substrates in the study of cardiac metabolism. [1-13 C]Acetoacetate was synthesized by catalysed hydrolysis, and both it and [1-13 C]β-hydroxybutyrate were hyperpolarized by dissolution dynamic nuclear polarization (DNP). Their metabolism was studied in isolated, perfused rat hearts. Hyperpolarized [1-13 C]acetoacetate metabolism was also studied in the in vivo rat heart in the fed and fasted states. Hyperpolarization of [1-13 C]acetoacetate and [1-13 C]β-hydroxybutyrate provided liquid state polarizations of 8 ± 2% and 3 ± 1%, respectively. The hyperpolarized T1 values for the two substrates were 28 ± 3 s (acetoacetate) and 20 ± 1 s (β-hydroxybutyrate). Multiple downstream metabolites were observed within the perfused heart, including acetylcarnitine, citrate and glutamate. In the in vivo heart, an increase in acetylcarnitine production from acetoacetate was observed in the fed state, as well as a potential reduction in glutamate. In this work, methods for the generation of hyperpolarized [1-13 C]acetoacetate and [1-13 C]β-hydroxybutyrate were investigated, and their metabolism was assessed in both isolated, perfused rat hearts and in the in vivo rat heart. These preliminary investigations show that DNP can be used as an effective in vivo probe of ketone body metabolism in the heart.
Collapse
Affiliation(s)
- Jack J. Miller
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
- Department of PhysicsUniversity of OxfordOxfordUK
| | - Daniel R. Ball
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
| | - Angus Z. Lau
- Sunnybrook Research InstituteImaging ResearchTorontoONCanada
- Department of Medical BiophysicsUniversity of TorontoTorontoONCanada
| | - Damian J. Tyler
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
| |
Collapse
|
16
|
Neveu MA, De Preter G, Joudiou N, Bol A, Brender JR, Saito K, Kishimoto S, Grégoire V, Jordan BF, Krishna MC, Feron O, Gallez B. Multi-modality imaging to assess metabolic response to dichloroacetate treatment in tumor models. Oncotarget 2018; 7:81741-81749. [PMID: 28082726 PMCID: PMC5340254 DOI: 10.18632/oncotarget.13176] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 10/19/2016] [Indexed: 01/20/2023] Open
Abstract
Reverting glycolytic metabolism is an attractive strategy for cancer therapy as upregulated glycolysis is a hallmark in various cancers. Dichloroacetate (DCA), long used to treat lactic acidosis in various pathologies, has emerged as a promising anti-cancer drug. By inhibiting the pyruvate dehydrogenase kinase, DCA reactivates the mitochondrial function and decreases the glycolytic flux in tumor cells resulting in cell cycle arrest and apoptosis. We recently documented that DCA was able to induce a metabolic switch preferentially in glycolytic cancer cells, leading to a more oxidative phenotype and decreasing proliferation, while oxidative cells remained less sensitive to DCA treatment. To evaluate the relevance of this observation in vivo, the aim of the present study was to characterize the effect of DCA in glycolytic MDA-MB-231 tumors and in oxidative SiHa tumors using advanced pharmacodynamic metabolic biomarkers. Oxygen consumption, studied by 17O magnetic resonance spectroscopy, glucose uptake, evaluated by 18F-FDG PET and pyruvate transformation into lactate, measured using hyperpolarized 13C-magnetic resonance spectroscopy, were monitored before and 24 hours after DCA treatment in tumor bearing mice. In both tumor models, no clear metabolic shift was observed. Surprisingly, all these imaging parameters concur to the conclusion that both glycolytic tumors and oxidative tumors presented a similar response to DCA. These results highlight a major discordance in metabolic cancer cell bioenergetics between in vitro and in vivo setups, indicating critical role of the local microenvironment in tumor metabolic behaviors.
Collapse
Affiliation(s)
- Marie-Aline Neveu
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Géraldine De Preter
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Nicolas Joudiou
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Anne Bol
- Radiation Oncology Department & Center for Molecular Imaging, Radiotherapy & Oncology, Institute of Experimental and Clinical Research, Université catholique de Louvain, Brussels, Belgium
| | - Jeffery R Brender
- Radiation Biology Branch, National Cancer Institute, NIH, Bethesda, USA
| | - Keita Saito
- Radiation Biology Branch, National Cancer Institute, NIH, Bethesda, USA
| | - Shun Kishimoto
- Radiation Biology Branch, National Cancer Institute, NIH, Bethesda, USA
| | - Vincent Grégoire
- Radiation Oncology Department & Center for Molecular Imaging, Radiotherapy & Oncology, Institute of Experimental and Clinical Research, Université catholique de Louvain, Brussels, Belgium
| | - Bénédicte F Jordan
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| | - Murali C Krishna
- Radiation Biology Branch, National Cancer Institute, NIH, Bethesda, USA
| | - Olivier Feron
- Pole of Pharmacology and Therapeutics, Institute of Experimental and Clinical Research, Université catholique de Louvain, Brussels, Belgium
| | - Bernard Gallez
- Biomedical Magnetic Resonance Research Group, Louvain Drug Research Institute, Université catholique de Louvain, Brussels, Belgium
| |
Collapse
|
17
|
von Morze C, Tropp J, Chen AP, Marco-Rius I, Van Criekinge M, Skloss TW, Mammoli D, Kurhanewicz J, Vigneron DB, Ohliger MA, Merritt ME. Sensitivity enhancement for detection of hyperpolarized 13 C MRI probes with 1 H spin coupling introduced by enzymatic transformation in vivo. Magn Reson Med 2017; 80:36-41. [PMID: 29193287 DOI: 10.1002/mrm.27000] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 09/28/2017] [Accepted: 10/17/2017] [Indexed: 12/16/2022]
Abstract
PURPOSE Although 1 H spin coupling is generally avoided in probes for hyperpolarized (HP) 13 C MRI, enzymatic transformations of biological interest can introduce large 13 C-1 H couplings in vivo. The purpose of this study was to develop and investigate the application of 1 H decoupling for enhancing the sensitivity for detection of affected HP 13 C metabolic products. METHODS A standalone 1 H decoupler system and custom concentric 13 C/1 H paddle coil setup were integrated with a clinical 3T MRI scanner for in vivo 13 C MR studies using HP [2-13 C]dihydroxyacetone, a novel sensor of hepatic energy status. Major 13 C-1 H coupling JCH = ∼150 Hz) is introduced after adenosine triphosphate-dependent enzymatic transformation of HP [2-13 C]dihydroxyacetone to [2-13 C]glycerol-3-phosphate in vivo. Application of WALTZ-16 1 H decoupling for elimination of large 13 C-1 H couplings was first tested in thermally polarized glycerol phantoms and then for in vivo HP MR studies in three rats, scanned both with and without decoupling. RESULTS As configured, 1 H-decoupled 13 C MR of thermally polarized glycerol and the HP metabolic product [2-13 C]glycerol-3-phosphate was achieved at forward power of approximately 15 W. High-quality 3-s dynamic in vivo HP 13 C MR scans were acquired with decoupling duty cycle of 5%. Application of 1 H decoupling resulted in sensitivity enhancement of 1.7-fold for detection of metabolic conversion of [2-13 C]dihydroxyacetone to HP [2-13 C]glycerol-3-phosphate in vivo. CONCLUSIONS Application of 1 H decoupling provides significant sensitivity enhancement for detection of HP 13 C metabolic products with large 1 H spin couplings, and is therefore expected to be useful for preclinical and potentially clinical HP 13 C MR studies. Magn Reson Med 80:36-41, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Collapse
Affiliation(s)
- Cornelius von Morze
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - James Tropp
- Berkshire Magnetics, Berkeley, California, USA
| | | | | | - Mark Van Criekinge
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | | | - Daniele Mammoli
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - John Kurhanewicz
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Daniel B Vigneron
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Michael A Ohliger
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Matthew E Merritt
- Department of Biochemistry, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
18
|
Milshteyn E, von Morze C, Reed GD, Shang H, Shin PJ, Zhu Z, Chen HY, Bok R, Goga A, Kurhanewicz J, Larson PEZ, Vigneron DB. Development of high resolution 3D hyperpolarized carbon-13 MR molecular imaging techniques. Magn Reson Imaging 2017; 38:152-162. [PMID: 28077268 PMCID: PMC5360530 DOI: 10.1016/j.mri.2017.01.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 01/08/2023]
Abstract
The goal of this project was to develop and apply techniques for T2 mapping and 3D high resolution (1.5mm isotropic; 0.003cm3) 13C imaging of hyperpolarized (HP) probes [1-13C]lactate, [1-13C]pyruvate, [2-13C]pyruvate, and [13C,15N2]urea in vivo. A specialized 2D bSSFP sequence was implemented on a clinical 3T scanner and used to obtain the first high resolution T2 maps of these different hyperpolarized compounds in both rats and tumor-bearing mice. These maps were first used to optimize timings for highest SNR for single time-point 3D bSSFP acquisitions with a 1.5mm isotropic spatial resolution of normal rats. This 3D acquisition approach was extended to serial dynamic imaging with 2-fold compressed sensing acceleration without changing spatial resolution. The T2 mapping experiments yielded measurements of T2 values of >1s for all compounds within rat kidneys/vasculature and TRAMP tumors, except for [2-13C]pyruvate which was ~730ms and ~320ms, respectively. The high resolution 3D imaging enabled visualization the biodistribution of [1-13C]lactate, [1-13C]pyruvate, and [2-13C]pyruvate within different kidney compartments as well as in the vasculature. While the mouse anatomy is smaller, the resolution was also sufficient to image the distribution of all compounds within kidney, vasculature, and tumor. The development of the specialized 3D sequence with compressed sensing provided improved structural and functional assessments at a high (0.003cm3) spatial and 2s temporal resolution in vivo utilizing HP 13C substrates by exploiting their long T2 values. This 1.5mm isotropic resolution is comparable to 1H imaging and application of this approach could be extended to future studies of uptake, metabolism, and perfusion in cancer and other disease models and may ultimately be of value for clinical imaging.
Collapse
Affiliation(s)
- Eugene Milshteyn
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA
| | - Cornelius von Morze
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | | | - Hong Shang
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA
| | - Peter J Shin
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Zihan Zhu
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA
| | - Hsin-Yu Chen
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA
| | - Robert Bok
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Andrei Goga
- Department of Cell and Tissue Biology, University of California, San Francisco, CA, USA
| | - John Kurhanewicz
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA
| | - Peder E Z Larson
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA
| | - Daniel B Vigneron
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA; UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco and University of California, Berkeley, CA, USA.
| |
Collapse
|
19
|
Siddiqui S, Kadlecek S, Pourfathi M, Xin Y, Mannherz W, Hamedani H, Drachman N, Ruppert K, Clapp J, Rizi R. The use of hyperpolarized carbon-13 magnetic resonance for molecular imaging. Adv Drug Deliv Rev 2017; 113:3-23. [PMID: 27599979 PMCID: PMC5783573 DOI: 10.1016/j.addr.2016.08.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 08/25/2016] [Accepted: 08/27/2016] [Indexed: 02/06/2023]
Abstract
Until recently, molecular imaging using magnetic resonance (MR) has been limited by the modality's low sensitivity, especially with non-proton nuclei. The advent of hyperpolarized (HP) MR overcomes this limitation by substantially enhancing the signal of certain biologically important probes through a process known as external nuclear polarization, enabling real-time assessment of tissue function and metabolism. The metabolic information obtained by HP MR imaging holds significant promise in the clinic, where it could play a critical role in disease diagnosis and therapeutic monitoring. This review will provide a comprehensive overview of the developments made in the field of hyperpolarized MR, including advancements in polarization techniques and delivery, probe development, pulse sequence optimization, characterization of healthy and diseased tissues, and the steps made towards clinical translation.
Collapse
Affiliation(s)
- Sarmad Siddiqui
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Stephen Kadlecek
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Mehrdad Pourfathi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yi Xin
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William Mannherz
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Hooman Hamedani
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicholas Drachman
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Kai Ruppert
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Justin Clapp
- Department of Anesthesiology and Critical Care, Hospital of the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Rahim Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104, USA.
| |
Collapse
|
20
|
Lane AN, Fan TWM. NMR-based Stable Isotope Resolved Metabolomics in systems biochemistry. Arch Biochem Biophys 2017; 628:123-131. [PMID: 28263717 DOI: 10.1016/j.abb.2017.02.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 02/24/2017] [Accepted: 02/27/2017] [Indexed: 01/23/2023]
Abstract
Metabolism is the basic activity of live cells, and monitoring the metabolic state provides a dynamic picture of the cells or tissues, and how they respond to external changes, for in disease or treatment with drugs. NMR is an extremely versatile analytical tool that can be applied to a wide range of biochemical problems. Despite its modest sensitivity its versatility make it an ideal tool for analyzing biochemical dynamics both in vitro and in vivo, especially when coupled with its isotope editing capabilities, from which isotope distributions can be readily determined. These are critical for any analyses of flux in live organisms. This review focuses on the utility of NMR spectroscopy in metabolomics, with an emphasis on NMR applications in stable isotope-enriched tracer research for elucidating biochemical pathways and networks with examples from nucleotide biochemistry. The knowledge gained from this area of research provides a ready link to genomic, epigenomic, transcriptomic, and proteomic information to achieve systems biochemical understanding of living cells and organisms.
Collapse
Affiliation(s)
- Andrew N Lane
- Center for Environmental Systems Biochemistry, University of Kentucky, USA; Department of Toxicology and Cancer Biology, University of Kentucky, USA.
| | - Teresa W-M Fan
- Center for Environmental Systems Biochemistry, University of Kentucky, USA; Department of Toxicology and Cancer Biology, University of Kentucky, USA
| |
Collapse
|
21
|
Lane AN, Higashi RM, Fan TWM. Preclinical models for interrogating drug action in human cancers using Stable Isotope Resolved Metabolomics (SIRM). Metabolomics 2016; 12:118. [PMID: 27489532 PMCID: PMC4968890 DOI: 10.1007/s11306-016-1065-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
AIMS In this review we compare the advantages and disadvantages of different model biological systems for determining the metabolic functions of cells in complex environments, how they may change in different disease states, and respond to therapeutic interventions. BACKGROUND All preclinical drug-testing models have advantages and drawbacks. We compare and contrast established cell, organoid and animal models with ex vivo organ or tissue culture and in vivo human experiments in the context of metabolic readout of drug efficacy. As metabolism reports directly on the biochemical state of cells and tissues, it can be very sensitive to drugs and/or other environmental changes. This is especially so when metabolic activities are probed by stable isotope tracing methods, which can also provide detailed mechanistic information on drug action. We have developed and been applying Stable Isotope-Resolved Metabolomics (SIRM) to examine metabolic reprogramming of human lung cancer cells in monoculture, in mouse xenograft/explant models, and in lung cancer patients in situ (Lane et al. 2011; T. W. Fan et al. 2011; T. W-M. Fan et al. 2012; T. W. Fan et al. 2012; Xie et al. 2014b; Ren et al. 2014a; Sellers et al. 2015b). We are able to determine the influence of the tumor microenvironment using these models. We have now extended the range of models to fresh human tissue slices, similar to those originally described by O. Warburg (Warburg 1923), which retain the native tissue architecture and heterogeneity with a paired benign versus cancer design under defined cell culture conditions. This platform offers an unprecedented human tissue model for preclinical studies on metabolic reprogramming of human cancer cells in their tissue context, and response to drug treatment (Xie et al. 2014a). As the microenvironment of the target human tissue is retained and individual patient's response to drugs is obtained, this platform promises to transcend current limitations of drug selection for clinical trials or treatments. CONCLUSIONS AND FUTURE WORK Development of ex vivo human tissue and animal models with humanized organs including bone marrow and liver show considerable promise for analyzing drug responses that are more relevant to humans. Similarly using stable isotope tracer methods with these improved models in advanced stages of the drug development pipeline, in conjunction with tissue biopsy is expected significantly to reduce the high failure rate of experimental drugs in Phase II and III clinical trials.
Collapse
Affiliation(s)
- Andrew N Lane
- Center for Environmental and Systems Biochemistry, University of Kentucky
| | - Richard M Higashi
- Center for Environmental and Systems Biochemistry, University of Kentucky
| | - Teresa W-M Fan
- Center for Environmental and Systems Biochemistry, University of Kentucky
| |
Collapse
|
22
|
Cao P, Shin PJ, Park I, Najac C, Marco-Rius I, Vigneron DB, Nelson SJ, Ronen SM, Larson PEZ. Accelerated high-bandwidth MR spectroscopic imaging using compressed sensing. Magn Reson Med 2016; 76:369-79. [PMID: 27228088 DOI: 10.1002/mrm.26272] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 03/27/2016] [Accepted: 04/19/2016] [Indexed: 12/12/2022]
Abstract
PURPOSE To develop a compressed sensing (CS) acceleration method with a high spectral bandwidth exploiting the spatial-spectral sparsity of MR spectroscopic imaging (MRSI). METHODS Accelerations were achieved using blip gradients during the readout to perform nonoverlapped and stochastically delayed random walks in kx -ky -t space, combined with block-Hankel matrix completion for efficient reconstruction. Both retrospective and prospective CS accelerations were applied to (13) C MRSI experiments, including in vivo rodent brain and liver studies with administrations of hyperpolarized [1-(13) C] pyruvate at 7.0 Tesla (T) and [2-(13) C] dihydroxyacetone at 3.0 T, respectively. RESULTS In retrospective undersampling experiments using in vivo 7.0 T data, the proposed method preserved spectral, spatial, and dynamic fidelities with R(2) ≥ 0.96 and ≥ 0.87 for pyruvate and lactate signals, respectively, 750-Hz spectral separation, and up to 6.6-fold accelerations. In prospective in vivo experiments, with 3.8-fold acceleration, the proposed method exhibited excellent spatial localization of metabolites and peak recovery for pyruvate and lactate at 7.0 T as well as for dihydroxyacetone and its metabolic products with a 4.5-kHz spectral span (140 ppm at 3.0 T). CONCLUSIONS This study demonstrated the feasibility of a new CS approach to accelerate high spectral bandwidth MRSI experiments. Magn Reson Med 76:369-379, 2016. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Peng Cao
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Peter J Shin
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Ilwoo Park
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Chloe Najac
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Irene Marco-Rius
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Daniel B Vigneron
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Sarah J Nelson
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Sabrina M Ronen
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| | - Peder E Z Larson
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA
| |
Collapse
|
23
|
Fan TWM, Lane AN. Applications of NMR spectroscopy to systems biochemistry. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2016; 92-93:18-53. [PMID: 26952191 PMCID: PMC4850081 DOI: 10.1016/j.pnmrs.2016.01.005] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Revised: 01/26/2016] [Accepted: 01/28/2016] [Indexed: 05/05/2023]
Abstract
The past decades of advancements in NMR have made it a very powerful tool for metabolic research. Despite its limitations in sensitivity relative to mass spectrometric techniques, NMR has a number of unparalleled advantages for metabolic studies, most notably the rigor and versatility in structure elucidation, isotope-filtered selection of molecules, and analysis of positional isotopomer distributions in complex mixtures afforded by multinuclear and multidimensional experiments. In addition, NMR has the capacity for spatially selective in vivo imaging and dynamical analysis of metabolism in tissues of living organisms. In conjunction with the use of stable isotope tracers, NMR is a method of choice for exploring the dynamics and compartmentation of metabolic pathways and networks, for which our current understanding is grossly insufficient. In this review, we describe how various direct and isotope-edited 1D and 2D NMR methods can be employed to profile metabolites and their isotopomer distributions by stable isotope-resolved metabolomic (SIRM) analysis. We also highlight the importance of sample preparation methods including rapid cryoquenching, efficient extraction, and chemoselective derivatization to facilitate robust and reproducible NMR-based metabolomic analysis. We further illustrate how NMR has been applied in vitro, ex vivo, or in vivo in various stable isotope tracer-based metabolic studies, to gain systematic and novel metabolic insights in different biological systems, including human subjects. The pathway and network knowledge generated from NMR- and MS-based tracing of isotopically enriched substrates will be invaluable for directing functional analysis of other 'omics data to achieve understanding of regulation of biochemical systems, as demonstrated in a case study. Future developments in NMR technologies and reagents to enhance both detection sensitivity and resolution should further empower NMR in systems biochemical research.
Collapse
Affiliation(s)
- Teresa W-M Fan
- Department of Toxicology and Cancer Biology, University of Kentucky, 789 S. Limestone St., Lexington, KY 40536, United States.
| | - Andrew N Lane
- Department of Toxicology and Cancer Biology, University of Kentucky, 789 S. Limestone St., Lexington, KY 40536, United States.
| |
Collapse
|
24
|
Ko H, Gong G, Jeong G, Choi I, Seo H, Lee Y. Hyperpolarization: Sensitivity Boost in Magnetic Resonance Spectroscopy and Imaging. JOURNAL OF THE KOREAN MAGNETIC RESONANCE SOCIETY 2015. [DOI: 10.6564/jkmrs.2015.19.3.124] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
25
|
Chaumeil MM, Najac C, Ronen SM. Studies of Metabolism Using (13)C MRS of Hyperpolarized Probes. Methods Enzymol 2015; 561:1-71. [PMID: 26358901 DOI: 10.1016/bs.mie.2015.04.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
First described in 2003, the dissolution dynamic nuclear polarization (DNP) technique, combined with (13)C magnetic resonance spectroscopy (MRS), has since been used in numerous metabolic studies and has become a valuable metabolic imaging method. DNP dramatically increases the level of polarization of (13)C-labeled compounds resulting in an increase in the signal-to-noise ratio (SNR) of over 50,000 fold for the MRS spectrum of hyperpolarized compounds. The high SNR enables rapid real-time detection of metabolism in cells, tissues, and in vivo. This chapter will present a comprehensive review of the DNP approaches that have been used to monitor metabolism in living systems. First, the list of (13)C DNP probes developed to date will be presented, with a particular focus on the most commonly used probe, namely [1-(13)C] pyruvate. In the next four sections, we will then describe the different factors that need to be considered when designing (13)C DNP probes for metabolic studies, conducting in vitro or in vivo hyperpolarized experiments, as well as acquiring, analyzing, and modeling hyperpolarized (13)C data.
Collapse
Affiliation(s)
- Myriam M Chaumeil
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Chloé Najac
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA
| | - Sabrina M Ronen
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, California, USA.
| |
Collapse
|
26
|
Purmal C, Kucejova B, Sherry AD, Burgess SC, Malloy CR, Merritt ME. Propionate stimulates pyruvate oxidation in the presence of acetate. Am J Physiol Heart Circ Physiol 2014; 307:H1134-41. [PMID: 25320331 DOI: 10.1152/ajpheart.00407.2014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Flux through pyruvate dehydrogenase (PDH) in the heart may be reduced by various forms of injury to the myocardium, or by oxidation of alternative substrates in normal heart tissue. It is important to distinguish these two mechanisms because imaging of flux through PDH based on the appearance of hyperpolarized (HP) [(13)C]bicarbonate derived from HP [1-(13)C]pyruvate has been proposed as a method for identifying viable myocardium. The efficacy of propionate for increasing PDH flux in the setting of PDH inhibition by an alternative substrate was studied using isotopomer analysis paired with exams using HP [1-(13)C]pyruvate. Hearts from C57/bl6 mice were supplied with acetate (2 mM) and glucose (8.25 mM). (13)C NMR spectra were acquired in a cryogenically cooled probe at 14.1 Tesla. After addition of hyperpolarized [1-(13)C]pyruvate, (13)C NMR signals from lactate, alanine, malate, and aspartate were easily detected, in addition to small signals from bicarbonate and CO2. The addition of propionate (2 mM) increased appearance of HP [(13)C]bicarbonate >30-fold without change in O2 consumption. Isotopomer analysis of extracts from the freeze-clamped hearts indicated that acetate was the preferred substrate for energy production, glucose contribution to energy production was minimal, and anaplerosis was stimulated in the presence of propionate. Under conditions where production of acetyl-CoA is dominated by the availability of an alternative substrate, acetate, propionate markedly stimulated PDH flux as detected by the appearance of hyperpolarized [(13)C]bicarbonate from metabolism of hyperpolarized [1-(13)C]pyruvate.
Collapse
Affiliation(s)
- Colin Purmal
- School of Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Blanka Kucejova
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas
| | - A Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Chemistry, University of Texas at Dallas, Richardson, Texas; and
| | - Shawn C Burgess
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Craig R Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas; Veterans Affairs North Texas Healthcare System, Dallas, Texas
| | - Matthew E Merritt
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas; Department of Chemistry, University of Texas at Dallas, Richardson, Texas; and
| |
Collapse
|
27
|
Lerche MH, Jensen PR, Karlsson M, Meier S. NMR insights into the inner workings of living cells. Anal Chem 2014; 87:119-32. [PMID: 25084065 DOI: 10.1021/ac501467x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Mathilde H Lerche
- Albeda Research , Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark
| | | | | | | |
Collapse
|
28
|
Ramirez MS, Lee J, Walker CM, Chen Y, Kingsley CV, De La Cerda J, Maldonado KL, Lai SY, Bankson JA. Feasibility of multianimal hyperpolarized (13) C MRS. Magn Reson Med 2014; 73:1726-32. [PMID: 24903532 DOI: 10.1002/mrm.25307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 04/18/2014] [Accepted: 05/11/2014] [Indexed: 11/10/2022]
Abstract
PURPOSE There is great potential for real-time investigation of metabolism with MRS and hyperpolarized (HP) (13) C agents. Unfortunately, HP technology has high associated costs and efficiency limitations that may constrain in vivo studies involving many animals. To improve the throughput of preclinical investigations, we evaluate the feasibility of performing HP MRS on multiple animals simultaneously. METHODS Simulations helped assess the viability of a dual-coil strategy for spatially localized multivolume MRS. A dual-mouse system was assembled and characterized with bench- and scanner-based experiments. Enzyme phantoms mixed with HP [1-(13) C] pyruvate emulated real-time metabolism and offered a controlled mechanism for evaluating system performance. Finally, a normal mouse and a mouse bearing a subcutaneous xenograft of colon cancer were simultaneously scanned in vivo using an agent containing HP [1-(13) C] pyruvate. RESULTS Geometric separation/rotation, active decoupling, and use of low input impedance preamplifiers permitted an encode-by-channel approach for spatially localized MRS. A precalibrated shim allowed straightforward metabolite differentiation in enzyme phantom and in vivo experiments at 7 Tesla, with performance similar to conventional acquisitions. CONCLUSION The initial feasibility of multi-animal HP (13) C MRS was established. Throughput scales with the number of simultaneously scanned animals, demonstrating the potential for significant improvements in study efficiency.
Collapse
Affiliation(s)
- Marc S Ramirez
- The Department of Imaging Physics, The University of Texas M.D. Anderson Cancer Center, Houston, Texas, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Stimulation of mitochondrial embryo metabolism by dichloroacetic acid in an aged mouse model improves embryo development and viability. Fertil Steril 2014; 101:1458-66. [DOI: 10.1016/j.fertnstert.2013.12.057] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Revised: 12/05/2013] [Accepted: 12/26/2013] [Indexed: 01/25/2023]
|
30
|
Keshari KR, Wilson DM. Chemistry and biochemistry of 13C hyperpolarized magnetic resonance using dynamic nuclear polarization. Chem Soc Rev 2013; 43:1627-59. [PMID: 24363044 DOI: 10.1039/c3cs60124b] [Citation(s) in RCA: 262] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The study of transient chemical phenomena by conventional NMR has proved elusive, particularly for non-(1)H nuclei. For (13)C, hyperpolarization using the dynamic nuclear polarization (DNP) technique has emerged as a powerful means to improve SNR. The recent development of rapid dissolution DNP methods has facilitated previously impossible in vitro and in vivo study of small molecules. This review presents the basics of the DNP technique, identification of appropriate DNP substrates, and approaches to increase hyperpolarized signal lifetimes. Also addressed are the biochemical events to which DNP-NMR has been applied, with descriptions of several probes that have met with in vivo success.
Collapse
Affiliation(s)
- Kayvan R Keshari
- Department of Radiology, Memorial Sloan-Kettering Cancer Center (MSKCC), New York, NY 10065, USA
| | | |
Collapse
|
31
|
Carpenter KLH, Jalloh I, Gallagher CN, Grice P, Howe DJ, Mason A, Timofeev I, Helmy A, Murphy MP, Menon DK, Kirkpatrick PJ, Carpenter TA, Sutherland GR, Pickard JD, Hutchinson PJ. (13)C-labelled microdialysis studies of cerebral metabolism in TBI patients. Eur J Pharm Sci 2013; 57:87-97. [PMID: 24361470 PMCID: PMC4013834 DOI: 10.1016/j.ejps.2013.12.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 12/07/2013] [Indexed: 12/23/2022]
Abstract
Human brain chemistry is incompletely understood and better methodologies are needed. Traumatic brain injury (TBI) causes metabolic perturbations, one result of which includes increased brain lactate levels. Attention has largely focussed on glycolysis, whereby glucose is converted to pyruvate and lactate, and is proposed to act as an energy source by feeding into neurons’ tricarboxylic acid (TCA) cycle, generating ATP. Also reportedly upregulated by TBI is the pentose phosphate pathway (PPP) that does not generate ATP but produces various molecules that are putatively neuroprotective, antioxidant and reparative, in addition to lactate among the end products. We have developed a novel combination of 13C-labelled cerebral microdialysis both to deliver 13C-labelled substrates into brains of TBI patients and recover the 13C-labelled metabolites, with high-resolution 13C NMR analysis of the microdialysates. This methodology has enabled us to achieve the first direct demonstration in humans that the brain can utilise lactate via the TCA cycle. We are currently using this methodology to make the first direct comparison of glycolysis and the PPP in human brain. In this article, we consider the application of 13C-labelled cerebral microdialysis for studying brain energy metabolism in patients. We set this methodology within the context of metabolic pathways in the brain, and 13C research modalities addressing them.
Collapse
Affiliation(s)
- Keri L H Carpenter
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, UK; Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, UK.
| | - Ibrahim Jalloh
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, UK
| | - Clare N Gallagher
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, UK; Division of Neurosurgery, Department of Clinical Neurosciences, University of Calgary, Canada
| | - Peter Grice
- Department of Chemistry, University of Cambridge, UK
| | - Duncan J Howe
- Department of Chemistry, University of Cambridge, UK
| | - Andrew Mason
- Department of Chemistry, University of Cambridge, UK
| | - Ivan Timofeev
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, UK
| | - Adel Helmy
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, UK
| | | | - David K Menon
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, UK; Division of Anaesthesia, Department of Medicine, University of Cambridge, UK
| | - Peter J Kirkpatrick
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, UK
| | - T Adrian Carpenter
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, UK
| | - Garnette R Sutherland
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Calgary, Canada
| | - John D Pickard
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, UK; Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, UK
| | - Peter J Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, UK; Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, UK
| |
Collapse
|
32
|
Josan S, Park JM, Hurd R, Yen YF, Pfefferbaum A, Spielman D, Mayer D. In vivo investigation of cardiac metabolism in the rat using MRS of hyperpolarized [1-13C] and [2-13C]pyruvate. NMR IN BIOMEDICINE 2013; 26:1680-7. [PMID: 23904148 PMCID: PMC3838505 DOI: 10.1002/nbm.3003] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 04/30/2013] [Accepted: 06/23/2013] [Indexed: 05/23/2023]
Abstract
Hyperpolarized (13)C MRS allows the in vivo assessment of pyruvate dehydrogenase complex (PDC) flux, which converts pyruvate to acetyl-coenzyme A (acetyl-CoA). [1-(13)C]pyruvate has been used to measure changes in cardiac PDC flux, with demonstrated increase in (13)C-bicarbonate production after dichloroacetate (DCA) administration. With [1-(13)C]pyruvate, the (13)C label is released as (13 CO2 /(13)C-bicarbonate, and, hence, does not allow us to follow the fate of acetyl-CoA. Pyruvate labeled in the C2 position has been used to track the (13)C label into the TCA (tricarboxylic acid) cycle and measure [5-(13)C]glutamate as well as study changes in [1-(13)C]acetylcarnitine with DCA and dobutamine. This work investigates changes in the metabolic fate of acetyl-CoA in response to metabolic interventions of DCA-induced increased PDC flux in the fed and fasted state, and increased cardiac workload with dobutamine in vivo in rat heart at two different pyruvate doses. DCA led to a modest increase in the (13)C labeling of [5-(13)C]glutamate, and a considerable increase in [1-(13)C]acetylcarnitine and [1,3-(13)C]acetoacetate peaks. Dobutamine resulted in an increased labeling of [2-(13)C]lactate, [2-(13)C]alanine and [5-(13)C]glutamate. The change in glutamate with dobutamine was observed using a high pyruvate dose but not with a low dose. The relative changes in the different metabolic products provide information about the relationship between PDC-mediated oxidation of pyruvate and its subsequent incorporation into the TCA cycle compared with other metabolic pathways. Using a high dose of pyruvate may provide an improved ability to observe changes in glutamate.
Collapse
Affiliation(s)
- Sonal Josan
- SRI International, Neuroscience Program, 333 Ravenswood Ave., Menlo Park, CA 94025
- Stanford University, Department of Radiology, Lucas MRI Center, 1201 Welch Rd. Stanford, CA 94305
| | - Jae Mo Park
- Stanford University, Department of Radiology, Lucas MRI Center, 1201 Welch Rd. Stanford, CA 94305
- Stanford University, Department of Electrical Engineering, Stanford, CA 94305
| | - Ralph Hurd
- GE Healthcare Applied Sciences Laboratory, 333 Ravenswood Ave., Menlo Park, CA 94025
| | - Yi-Fen Yen
- Stanford University, Department of Radiology, Lucas MRI Center, 1201 Welch Rd. Stanford, CA 94305
| | - Adolf Pfefferbaum
- SRI International, Neuroscience Program, 333 Ravenswood Ave., Menlo Park, CA 94025
- Stanford University, Department of Psychiatry and Behavioral Sciences, 401 Quarry Rd., Stanford, CA 94305
| | - Daniel Spielman
- Stanford University, Department of Radiology, Lucas MRI Center, 1201 Welch Rd. Stanford, CA 94305
- Stanford University, Department of Electrical Engineering, Stanford, CA 94305
| | - Dirk Mayer
- SRI International, Neuroscience Program, 333 Ravenswood Ave., Menlo Park, CA 94025
- Stanford University, Department of Radiology, Lucas MRI Center, 1201 Welch Rd. Stanford, CA 94305
| |
Collapse
|
33
|
Josan S, Hurd R, Park JM, Yen YF, Watkins R, Pfefferbaum A, Spielman D, Mayer D. Dynamic metabolic imaging of hyperpolarized [2-(13) C]pyruvate using spiral chemical shift imaging with alternating spectral band excitation. Magn Reson Med 2013; 71:2051-8. [PMID: 23878057 DOI: 10.1002/mrm.24871] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 05/23/2013] [Accepted: 06/12/2013] [Indexed: 12/25/2022]
Abstract
PURPOSE In contrast to [1-(13) C]pyruvate, hyperpolarized [2-(13) C]pyruvate permits the ability to follow the (13) C label beyond flux through pyruvate dehydrogenase complex and investigate the incorporation of acetyl-coenzyme A into different metabolic pathways. However, chemical shift imaging (CSI) with [2-(13) C]pyruvate is challenging owing to the large spectral dispersion of the resonances, which also leads to severe chemical shift displacement artifacts for slice-selective acquisitions. METHODS This study introduces a sequence for three-dimensional CSI of [2-(13) C]pyruvate using spectrally selective excitation of limited frequency bands containing a subset of metabolites. Dynamic CSI data were acquired alternately from multiple frequency bands in phantoms for sequence testing and in vivo in rat heart. RESULTS Phantom experiments verified the radiofrequency pulse design and demonstrated that the signal behavior of each group of resonances was unaffected by excitation of the other frequency bands. Dynamic three-dimensional (13) C CSI data demonstrated the sequence capability to image pyruvate, lactate, acetylcarnitine, glutamate, and acetoacetate, enabling the analysis of organ-specific spectra and metabolite time courses. CONCLUSIONS The presented method allows CSI of widely separated resonances without chemical shift displacement artifact, acquiring multiple frequency bands alternately to obtain dynamic time-course information. This approach enables robust imaging of downstream metabolic products of acetyl-coenzyme A with hyperpolarized [2-(13) C]pyruvate.
Collapse
Affiliation(s)
- Sonal Josan
- SRI International, Neuroscience Program, Menlo Park, California, USA; Department of Radiology, Stanford University, Lucas MRI Center, Stanford, California, USA
| | | | | | | | | | | | | | | |
Collapse
|
34
|
Barb A, Hekmatyar S, Glushka J, Prestegard J. Probing alanine transaminase catalysis with hyperpolarized 13CD3-pyruvate. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 228:59-65. [PMID: 23357427 PMCID: PMC3654812 DOI: 10.1016/j.jmr.2012.12.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 12/19/2012] [Accepted: 12/21/2012] [Indexed: 05/05/2023]
Abstract
Hyperpolarized metabolites offer a tremendous sensitivity advantage (>10(4) fold) when measuring flux and enzyme activity in living tissues by magnetic resonance methods. These sensitivity gains can also be applied to mechanistic studies that impose time and metabolite concentration limitations. Here we explore the use of hyperpolarization by dissolution dynamic nuclear polarization (DNP) in mechanistic studies of alanine transaminase (ALT), a well-established biomarker of liver disease and cancer that converts pyruvate to alanine using glutamate as a nitrogen donor. A specific deuterated, (13)C-enriched analog of pyruvic acid, (13)C3D(3)-pyruvic acid, is demonstrated to have advantages in terms of detection by both direct (13)C observation and indirect observation through methyl protons introduced by ALT-catalyzed H-D exchange. Exchange on injecting hyperpolarized (13)C3D(3)-pyruvate into ALT dissolved in buffered (1)H(2)O, combined with an experimental approach to measure proton incorporation, provided information on mechanistic details of transaminase action on a 1.5s timescale. ALT introduced, on average, 0.8 new protons into the methyl group of the alanine produced, indicating the presence of an off-pathway enamine intermediate. The opportunities for exploiting mechanism-dependent molecular signatures as well as indirect detection of hyperpolarized (13)C3-pyruvate and products in imaging applications are discussed.
Collapse
Affiliation(s)
| | | | | | - J.H. Prestegard
- Corresponding author. Fax: +1 706 542 4412. (J.H. Prestegard)
| |
Collapse
|
35
|
Hu S, Larson PEZ, Vancriekinge M, Leach AM, Park I, Leon C, Zhou J, Shin PJ, Reed G, Keselman P, von Morze C, Yoshihara H, Bok RA, Nelson SJ, Kurhanewicz J, Vigneron DB. Rapid sequential injections of hyperpolarized [1-¹³C]pyruvate in vivo using a sub-kelvin, multi-sample DNP polarizer. Magn Reson Imaging 2012; 31:490-6. [PMID: 23107275 DOI: 10.1016/j.mri.2012.09.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 09/09/2012] [Accepted: 09/09/2012] [Indexed: 11/16/2022]
Abstract
The development of hyperpolarized technology utilizing dynamic nuclear polarization (DNP) has enabled the rapid measurement of (13)C metabolism in vivo with very high SNR. However, with traditional DNP equipment, consecutive injections of a hyperpolarized compound in an animal have been subject to a practical minimum time between injections governed by the polarization build-up time, which is on the order of an hour for [1-(13)C]pyruvate. This has precluded the monitoring of metabolic changes occurring on a faster time scale. In this study, we demonstrated the ability to acquire in vivo dynamic magnetic resonance spectroscopy (MRS) and 3D magnetic resonance spectroscopic imaging (MRSI) data in normal rats with a 5 min interval between injections of hyperpolarized [1-(13)C]pyruvate using a prototype, sub-Kelvin dynamic nuclear polarizer with the capability to simultaneously polarize up to 4 samples and dissolve them in rapid succession. There were minimal perturbations in the hyperpolarized spectra as a result of the multiple injections, suggesting that such an approach would not confound the investigation of metabolism occurring on this time scale. As an initial demonstration of the application of this technology and approach for monitoring rapid changes in metabolism as a result of a physiological intervention, we investigated the pharmacodynamics of the anti-cancer agent dichloroacetate (DCA), collecting hyperpolarized data before administration of DCA, 1 min after administration, and 6 min after administration. Dramatic increases in (13)C-bicarbonate were detected just 1 min (as well as 6 min) after DCA administration.
Collapse
Affiliation(s)
- Simon Hu
- Dept. of Radiology and Biomedical Imaging, Box 2512, University of California, San Francisco, 1700 4th St. QB3 Building, Suite 102, San Francisco, CA 94158-2512, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|