51
|
Keshari KR, Kurhanewicz J, Macdonald JM, Wilson DM. Generating contrast in hyperpolarized 13C MRI using ligand-receptor interactions. Analyst 2012; 137:3427-9. [PMID: 22655289 DOI: 10.1039/c2an35406c] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report the imaging of β-cyclodextrin-benzoic acid binding at 14T using hyperpolarized (13)C magnetic resonance (MR). Benzoic acid was polarized using a dynamic nuclear polarization (DNP) approach and combined with β-cyclodextrin in aqueous solution. As anticipated, decreases in the spin-lattice relaxation constant (T(1)) were observed with decreases in the ligand-receptor ratio. The calculated log K was approximately 1.7, similar to previously reported binding constants. Hyperpolarized [1-(13)C] benzoic acid was used to interrogate solutions of variable β-cyclodextrin concentrations, with the mixtures imaged at 14T using a 3D frequency-selective MR sequence. Differences in β-cyclodextrin concentration were easily visualized. These results suggest that hyperpolarized (13)C MR could be used in vivo to determine the presence and density of receptors for a given ligand-receptor pair.
Collapse
Affiliation(s)
- Kayvan R Keshari
- Department of Radiology, University of California San Francisco, San Francisco, USA
| | | | | | | |
Collapse
|
52
|
Jeffries RE, Macdonald JM. New advances in MR-compatible bioartificial liver. NMR IN BIOMEDICINE 2012; 25:427-42. [PMID: 22351642 PMCID: PMC4332620 DOI: 10.1002/nbm.1633] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 08/23/2010] [Accepted: 10/05/2010] [Indexed: 05/31/2023]
Abstract
MR-compatible bioartificial liver (BAL) studies have been performed for 30 years and are reviewed. There are two types of study: (i) metabolism and drug studies using multinuclear MRS; primarily short-term (< 8 h) studies; (ii) the use of multinuclear MRS and MRI to noninvasively define the features and functions of BAL systems for long-term liver tissue engineering. In the latter, these systems often undergo not only modification of the perfusion system, but also the construction of MR radiofrequency probes around the bioreactor. We present novel MR-compatible BALs and the use of multinuclear MRS ((13)C, (19)F, (31)P) for the noninvasive monitoring of their growth, metabolism and viability, as well as (1)H MRI methods for the determination of flow profiles, diffusion, cell distribution, quality assurance and bioreactor integrity. Finally, a simple flexible coil design and circuit, and life support system, are described that can make almost any BAL MR-compatible.
Collapse
Affiliation(s)
- Rex E Jeffries
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7575, USA
| | | |
Collapse
|
53
|
Analysis of cancer metabolism by imaging hyperpolarized nuclei: prospects for translation to clinical research. Neoplasia 2011; 13:81-97. [PMID: 21403835 DOI: 10.1593/neo.101102] [Citation(s) in RCA: 563] [Impact Index Per Article: 43.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 10/18/2010] [Accepted: 10/22/2010] [Indexed: 12/13/2022] Open
Abstract
A major challenge in cancer biology is to monitor and understand cancer metabolism in vivo with the goal of improved diagnosis and perhaps therapy. Because of the complexity of biochemical pathways, tracer methods are required for detecting specific enzyme-catalyzed reactions. Stable isotopes such as (13)C or (15)N with detection by nuclear magnetic resonance provide the necessary information about tissue biochemistry, but the crucial metabolites are present in low concentration and therefore are beyond the detection threshold of traditional magnetic resonance methods. A solution is to improve sensitivity by a factor of 10,000 or more by temporarily redistributing the populations of nuclear spins in a magnetic field, a process termed hyperpolarization. Although this effect is short-lived, hyperpolarized molecules can be generated in an aqueous solution and infused in vivo where metabolism generates products that can be imaged. This discovery lifts the primary constraint on magnetic resonance imaging for monitoring metabolism-poor sensitivity-while preserving the advantage of biochemical information. The purpose of this report was to briefly summarize the known abnormalities in cancer metabolism, the value and limitations of current imaging methods for metabolism, and the principles of hyperpolarization. Recent preclinical applications are described. Hyperpolarization technology is still in its infancy, and current polarizer equipment and methods are suboptimal. Nevertheless, there are no fundamental barriers to rapid translation of this exciting technology to clinical research and perhaps clinical care.
Collapse
|
54
|
Brindle KM, Bohndiek SE, Gallagher FA, Kettunen MI. Tumor imaging using hyperpolarized 13C magnetic resonance spectroscopy. Magn Reson Med 2011; 66:505-19. [PMID: 21661043 DOI: 10.1002/mrm.22999] [Citation(s) in RCA: 210] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 04/14/2011] [Accepted: 04/16/2011] [Indexed: 02/06/2023]
Abstract
Dynamic nuclear polarization is an emerging technique for increasing the sensitivity of magnetic resonance imaging and spectroscopy, particularly for low-γ nuclei. The technique has been applied recently to a number of 13C-labeled cell metabolites in biological systems: the increase in signal-to-noise allows the spatial distribution of an injected molecule to be imaged as well as its metabolic product or products. This review highlights the most significant molecules investigated to date in preclinical cancer models, either in terms of their demonstrated metabolism in vivo or the biological processes that they can probe. In particular, label exchange between hyperpolarized 13C-labeled pyruvate and lactate, catalyzed by lactate dehydrogenase, has been shown to have a number of potential applications. Finally, techniques to image these molecules are also discussed as well as methods that may extend the lifetime of the hyperpolarized signal. Hyperpolarized magnetic resonance imaging and magnetic resonance spectroscopic imaging have shown great promise for the imaging of cancer in preclinical work, both for diagnosis and for monitoring therapy response. If the challenges in translating this technique to human imaging can be overcome, then it has the potential to significantly alter the management of cancer patients.
Collapse
Affiliation(s)
- Kevin M Brindle
- Cancer Research UK, Cambridge Research Institute, and Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom.
| | | | | | | |
Collapse
|
55
|
NMR spectroscopy as a tool to close the gap on metabolite characterization under MIST. Bioanalysis 2011; 2:1263-76. [PMID: 21083239 DOI: 10.4155/bio.10.77] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Withdrawals from the market due to unforeseen adverse events have triggered changes in the way therapeutics are discovered and developed. This has resulted in an emphasis on truly understanding the efficacy and toxicity profile of new chemical entities (NCE) and the contributions of their metabolites to on-target pharmacology and off-target receptor-mediated toxicology. Members of the pharmaceutical industry, scientific community and regulatory agencies have held dialogues with respect to metabolites in safety testing (MIST); and both the US FDA and International Conference on Harmonisation have issued guidances with respect to when and how to characterize metabolites for human safety testing. This review provides a brief overview of NMR spectroscopy as applied to the structure elucidation and quantification of drug metabolites within the drug discovery and development process. It covers advances in this technique, including cryogenic cooling of detection circuitry for enhanced sensitivity, hyphenated LC-NMR techniques, improved dynamic range through new solvent-suppression pulse sequences and quantitation. These applications add to the already diverse NMR toolkit and further anchor NMR as a technique that is directly applicable to meeting the requirements of MIST guidelines.
Collapse
|
56
|
Lumata L, Kovacs Z, Malloy C, Sherry AD, Merritt M. The effect of 13C enrichment in the glassing matrix on dynamic nuclear polarization of [1-13C]pyruvate. Phys Med Biol 2011; 56:N85-92. [PMID: 21285486 PMCID: PMC3144154 DOI: 10.1088/0031-9155/56/5/n01] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Dimethyl sulfoxide (DMSO) can effectively form a glassy matrix necessary for dynamic nuclear polarization (DNP) experiments. We tested the effects of (13)C enrichment in DMSO on DNP of [1-(13)C]pyruvate doped with trityl radical OX063Me. We found that the polarization build-up time τ of pyruvate in (13)C-labeled DMSO glassing solution is twice as fast as the unenriched DMSO while the nuclear magnetic resonance enhancement was unchanged. This indicates that (13)C-(13)C spin diffusion is a limiting factor in the kinetics of DNP in this system, but it has a minimal effect on the absolute value of polarization achievable for the target.
Collapse
Affiliation(s)
- Lloyd Lumata
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390 USA
| | - Zoltan Kovacs
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390 USA
| | - Craig Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390 USA
| | - A. Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390 USA
- Department of Chemistry, University of Texas at Dallas, Richardson, Texas 75080 USA
| | - Matthew Merritt
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390 USA
| |
Collapse
|
57
|
Tikunov AP, Johnson CB, Lee H, Stoskopf MK, Macdonald JM. Metabolomic investigations of American oysters using H-NMR spectroscopy. Mar Drugs 2010; 8:2578-96. [PMID: 21116407 PMCID: PMC2992993 DOI: 10.3390/md8102578] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Revised: 09/22/2010] [Accepted: 09/30/2010] [Indexed: 02/02/2023] Open
Abstract
The Eastern oyster (Crassostrea virginica) is a useful, robust model marine organism for tissue metabolism studies. Its relatively few organs are easily delineated and there is sufficient understanding of their functions based on classical assays to support interpretation of advanced spectroscopic approaches. Here we apply high-resolution proton nuclear magnetic resonance ((1)H NMR)-based metabolomic analysis to C. virginica to investigate the differences in the metabolic profile of different organ groups, and magnetic resonance imaging (MRI) to non-invasively identify the well separated organs. Metabolites were identified in perchloric acid extracts of three portions of the oyster containing: (1) adductor muscle, (2) stomach and digestive gland, and (3) mantle and gills. Osmolytes dominated the metabolome in all three organ blocks with decreasing concentration as follows: betaine > taurine > proline > glycine > ß-alanine > hypotaurine. Mitochondrial metabolism appeared most pronounced in the adductor muscle with elevated levels of carnitine facilitating ß-oxidation, and ATP, and phosphoarginine synthesis, while glycogen was elevated in the mantle/gills and stomach/digestive gland. A biochemical schematic is presented that relates metabolites to biochemical pathways correlated with physiological organ functions. This study identifies metabolites and corresponding (1)H NMR peak assignments for future NMR-based metabolomic studies in oysters.
Collapse
Affiliation(s)
- Andrey P. Tikunov
- Joint Department of Biomedical Engineering, NC State University and UNC Chapel Hill, Chapel Hill, NC 27599, USA; E-Mail: (H.L.)
- Environmental Medicine Consortium, NC State University, 4700 Hillsborough St., Raleigh, NC 27606, USA; E-Mail: (J.M.M.)
| | - Christopher B. Johnson
- Department of Surgery, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC 29425, USA; E-Mail:
| | - Haakil Lee
- Joint Department of Biomedical Engineering, NC State University and UNC Chapel Hill, Chapel Hill, NC 27599, USA; E-Mail: (H.L.)
- Environmental Medicine Consortium, NC State University, 4700 Hillsborough St., Raleigh, NC 27606, USA; E-Mail: (J.M.M.)
| | - Michael K. Stoskopf
- Joint Department of Biomedical Engineering, NC State University and UNC Chapel Hill, Chapel Hill, NC 27599, USA; E-Mail: (H.L.)
- Environmental Medicine Consortium, NC State University, 4700 Hillsborough St., Raleigh, NC 27606, USA; E-Mail: (J.M.M.)
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 4700 Hillsborough St., Raleigh, NC 27606, USA; E-Mail:
| | - Jeffrey M. Macdonald
- Joint Department of Biomedical Engineering, NC State University and UNC Chapel Hill, Chapel Hill, NC 27599, USA; E-Mail: (H.L.)
- Environmental Medicine Consortium, NC State University, 4700 Hillsborough St., Raleigh, NC 27606, USA; E-Mail: (J.M.M.)
| |
Collapse
|
58
|
Dewar BJ, Keshari K, Jeffries R, Dzeja P, Graves LM, Macdonald JM. Metabolic assessment of a novel chronic myelogenous leukemic cell line and an imatinib resistant subline by H NMR spectroscopy. Metabolomics 2010; 6:439-450. [PMID: 20676217 PMCID: PMC2899017 DOI: 10.1007/s11306-010-0204-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2009] [Accepted: 03/04/2010] [Indexed: 11/07/2022]
Abstract
The goal of this study was to examine metabolic differences between a novel chronic myelogenous leukemic (CML) cell line, MyL, and a sub-clone, MyL-R, which displays enhanced resistance to the targeted Bcr-Abl tyrosine kinase inhibitor imatinib. (1)H nuclear magnetic resonance (NMR) spectroscopy was carried out on cell extracts and conditioned media from each cell type. Both principal component analysis (PCA) and specific metabolite identification and quantification were used to examine metabolic differences between the cell types. MyL cells showed enhanced glucose removal from the media compared to MyL-R cells with significant differences in production rates of the glycolytic end-products, lactate and alanine. Interestingly, the total intracellular creatine pool (creatine + phosphocreatine) was significantly elevated in MyL-R compared to MyL cells. We further demonstrated that the MyL-R cells converted the creatine to phosphocreatine using non-invasive monitoring of perfused alginate-encapsulated MyL-R and MyL cells by in vivo (31)P NMR spectroscopy and subsequent HPLC analysis of extracts. Our data demonstrated a clear difference in the metabolite profiles of drug-resistant and sensitive cells, with the biggest difference being an elevation of creatine metabolites in the imatinib-resistant MyL-R cells.
Collapse
Affiliation(s)
- Brian J. Dewar
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, CB# 7575, 152 MacNider Hall, Chapel Hill, NC 27599-7575 USA
| | - Kayvan Keshari
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, CB# 7575, 152 MacNider Hall, Chapel Hill, NC 27599-7575 USA
| | - Rex Jeffries
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, CB# 7575, 152 MacNider Hall, Chapel Hill, NC 27599-7575 USA
| | - Petras Dzeja
- Division of Cardiovascular Diseases, Departments of Medicine, Molecular Pharmacology, and Experimental Therapeutics, Mayo Clinic, Rochester, MN 55905 USA
| | - Lee M. Graves
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
| | - Jeffrey M. Macdonald
- Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599 USA
- Department of Biomedical Engineering, University of North Carolina at Chapel Hill, CB# 7575, 152 MacNider Hall, Chapel Hill, NC 27599-7575 USA
| |
Collapse
|