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Zaidi M, Ma J, Thomas BP, Peña S, Harrison CE, Chen J, Lin SH, Derner KA, Baxter JD, Liticker J, Malloy CR, Bartnik-Olson B, Park JM. Functional activation of pyruvate dehydrogenase in human brain using hyperpolarized [1- 13 C]pyruvate. Magn Reson Med 2024; 91:1822-1833. [PMID: 38265104 PMCID: PMC10950523 DOI: 10.1002/mrm.30015] [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: 06/03/2023] [Revised: 12/28/2023] [Accepted: 12/29/2023] [Indexed: 01/25/2024]
Abstract
PURPOSE Pyruvate, produced from either glucose, glycogen, or lactate, is the dominant precursor of cerebral oxidative metabolism. Pyruvate dehydrogenase (PDH) flux is a direct measure of cerebral mitochondrial function and metabolism. Detection of [13 C]bicarbonate in the brain from hyperpolarized [1-13 C]pyruvate using carbon-13 (13 C) MRI provides a unique opportunity for assessing PDH flux in vivo. This study is to assess changes in cerebral PDH flux in response to visual stimuli using in vivo 13 C MRS with hyperpolarized [1-13 C]pyruvate. METHODS From seven sedentary adults in good general health, time-resolved [13 C]bicarbonate production was measured in the brain using 90° flip angles with minimal perturbation of its precursors, [1-13 C]pyruvate and [1-13 C]lactate, to test the hypothesis that the appearance of [13 C]bicarbonate signals in the brain reflects the metabolic changes associated with neuronal activation. With a separate group of healthy participants (n = 3), the likelihood of the bolus-injected [1-13 C]pyruvate being converted to [1-13 C]lactate prior to decarboxylation was investigated by measuring [13 C]bicarbonate production with and without [1-13 C]lactate saturation. RESULTS In the course of visual stimulation, the measured [13 C]bicarbonate signal normalized to the total 13 C signal in the visual cortex increased by 17.1% ± 15.9% (p = 0.017), whereas no significant change was detected in [1-13 C]lactate. Proton BOLD fMRI confirmed the regional activation in the visual cortex with the stimuli. Lactate saturation decreased bicarbonate-to-pyruvate ratio by 44.4% ± 9.3% (p < 0.01). CONCLUSION We demonstrated the utility of 13 C MRS with hyperpolarized [1-13 C]pyruvate for assessing the activation of cerebral PDH flux via the detection of [13 C]bicarbonate production.
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Affiliation(s)
- Maheen Zaidi
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Junjie Ma
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
- GE Precision Healthcare, Jersey City, New Jersey, USA 07302
| | - Binu P. Thomas
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Salvador Peña
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Crystal E. Harrison
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Jun Chen
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Sung-Han Lin
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Kelley A. Derner
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Jeannie D. Baxter
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Jeff Liticker
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Craig R. Malloy
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
| | - Brenda Bartnik-Olson
- Department of Radiology, Loma Linda University, Loma Linda, California, USA 92354
| | - Jae Mo Park
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
- Department of Biomedical Engineering, The University of Texas Southwestern Medical Center, Dallas, Texas, USA 75390
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Perolina E, Meissner S, Raos B, Harland B, Thakur S, Svirskis D. Translating ultrasound-mediated drug delivery technologies for CNS applications. Adv Drug Deliv Rev 2024; 208:115274. [PMID: 38452815 DOI: 10.1016/j.addr.2024.115274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 02/18/2024] [Accepted: 03/01/2024] [Indexed: 03/09/2024]
Abstract
Ultrasound enhances drug delivery into the central nervous system (CNS) by opening barriers between the blood and CNS and by triggering release of drugs from carriers. A key challenge in translating setups from in vitro to in vivo settings is achieving equivalent acoustic energy delivery. Multiple devices have now been demonstrated to focus ultrasound to the brain, with concepts emerging to also target the spinal cord. Clinical trials to date have used ultrasound to facilitate the opening of the blood-brain barrier. While most have focused on feasibility and safety considerations, therapeutic benefits are beginning to emerge. To advance translation of these technologies for CNS applications, researchers should standardise exposure protocol and fine-tune ultrasound parameters. Computational modelling should be increasingly used as a core component to develop both in vitro and in vivo setups for delivering accurate and reproducible ultrasound to the CNS. This field holds promise for transformative advancements in the management and pharmacological treatment of complex and challenging CNS disorders.
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Affiliation(s)
- Ederlyn Perolina
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Svenja Meissner
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Brad Raos
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Bruce Harland
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Sachin Thakur
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand
| | - Darren Svirskis
- School of Pharmacy, Faculty of Medical and Health Sciences, University of Auckland, 85 Park Road, Auckland 1023, New Zealand.
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Římal V, Bunyatova EI, Štěpánková H. Efficient Scavenging of TEMPOL Radical by Ascorbic Acid in Solution and Related Prolongation of 13C and 1H Nuclear Spin Relaxation Times of the Solute. Molecules 2024; 29:738. [PMID: 38338481 PMCID: PMC10856727 DOI: 10.3390/molecules29030738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/28/2024] [Accepted: 01/28/2024] [Indexed: 02/12/2024] Open
Abstract
Dynamic nuclear polarization for nuclear magnetic resonance (NMR) spectroscopy and imaging uses free radicals to strongly enhance the NMR signal of a compound under investigation. At the same time, the radicals shorten significantly its nuclear spin relaxation times which reduces the time window available for the experiments. Radical scavenging can overcome this drawback. Our work presents a detailed study of the reduction of the TEMPOL radical by ascorbic acid in solution by high-resolution NMR. Carbon-13 and hydrogen-1 nuclear spin relaxations are confirmed to be restored to their values without TEMPOL. Reaction mechanism, kinetics, and the influence of pD and viscosity are thoroughly discussed. The detailed investigation conducted in this work should help with choosing suitable concentrations in the samples for dynamic nuclear polarization and optimizing the measurement protocols.
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Affiliation(s)
- Václav Římal
- Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 18000 Prague 8, Czech Republic;
| | | | - Helena Štěpánková
- Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 18000 Prague 8, Czech Republic;
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Takahashi AM, Sharma J, Guarin DO, Miller J, Wakimoto H, Cahill DP, Yen YF. Inductively coupled, transmit-receive coils for proton MRI and X-nucleus MRI/MRS in small animals. JOURNAL OF MAGNETIC RESONANCE OPEN 2023; 16-17:100123. [PMID: 38046795 PMCID: PMC10691784 DOI: 10.1016/j.jmro.2023.100123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
We report several inductively coupled RF coil designs that are very easy to construct, produce high signal-to-noise ratio (SNR) and high spatial resolution while accommodating life support, anesthesia and monitoring in small animals. Inductively coupled surface coils were designed for hyperpolarized 13 C MR spectroscopic imaging (MRSI) of mouse brain, with emphases on the simplicity of the circuit design, ease of use, whole-brain coverage, and high SNR. The simplest form was a resonant loop designed to crown the mouse head for a snug fit to achieve full coverage of the brain with high sensitivity when inductively coupled to a broadband pick-up coil. Here, we demonstrated the coil's performance in hyperpolarized 13 C MRSI of a normal mouse and a glioblastoma mouse model at 4.7 T. High SNR exceeding 70:1 was obtained in the brain with good spatial resolution (1.53 mm × 1.53 mm). Similar inductively coupled loop for other X-nuclei can be made very easily in a few minutes and achieve high performance, as demonstrated in 31 P spectroscopy. Similar design concept was expanded to splitable, inductively coupled volume coils for high-resolution proton MRI of marmoset at 3T and 9.4T, to easily accommodate head restraint, vital-sign monitoring, and anesthesia delivery.
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Affiliation(s)
- Atsushi M. Takahashi
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, McGovern Institute for Brain Research, Cambridge, MA 02139, USA
| | - Jitendra Sharma
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, McGovern Institute for Brain Research, Cambridge, MA 02139, USA
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
- Stanley Center for Psychiatric Research, Broad Institute, MIT, Cambridge, MA 02139, USA
- Tan and Yang Center for Autism Research, McGovern Institute for Brain Research, MIT, Cambridge MA 02139, USA
| | - David O. Guarin
- Polarize ApS, Frederiksberg 1808, Denmark
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
| | - Julie Miller
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Hiroaki Wakimoto
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Daniel P. Cahill
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Yi-Fen Yen
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA 02129, USA
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Guglielmetti C, Cordano C, Najac C, Green AJ, Chaumeil MM. Imaging immunomodulatory treatment responses in a multiple sclerosis mouse model using hyperpolarized 13C metabolic MRI. COMMUNICATIONS MEDICINE 2023; 3:71. [PMID: 37217574 DOI: 10.1038/s43856-023-00300-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 05/03/2023] [Indexed: 05/24/2023] Open
Abstract
BACKGROUND In recent years, the ability of conventional magnetic resonance imaging (MRI), including T1 contrast-enhanced (CE) MRI, to monitor high-efficacy therapies and predict long-term disability in multiple sclerosis (MS) has been challenged. Therefore, non-invasive methods to improve MS lesions detection and monitor therapy response are needed. METHODS We studied the combined cuprizone and experimental autoimmune encephalomyelitis (CPZ-EAE) mouse model of MS, which presents inflammatory-mediated demyelinated lesions in the central nervous system as commonly seen in MS patients. Using hyperpolarized 13C MR spectroscopy (MRS) metabolic imaging, we measured cerebral metabolic fluxes in control, CPZ-EAE and CPZ-EAE mice treated with two clinically-relevant therapies, namely fingolimod and dimethyl fumarate. We also acquired conventional T1 CE MRI to detect active lesions, and performed ex vivo measurements of enzyme activities and immunofluorescence analyses of brain tissue. Last, we evaluated associations between imaging and ex vivo parameters. RESULTS We show that hyperpolarized [1-13C]pyruvate conversion to lactate is increased in the brain of untreated CPZ-EAE mice when compared to the control, reflecting immune cell activation. We further demonstrate that this metabolic conversion is significantly decreased in response to the two treatments. This reduction can be explained by increased pyruvate dehydrogenase activity and a decrease in immune cells. Importantly, we show that hyperpolarized 13C MRS detects dimethyl fumarate therapy, whereas conventional T1 CE MRI cannot. CONCLUSIONS In conclusion, hyperpolarized MRS metabolic imaging of [1-13C]pyruvate detects immunological responses to disease-modifying therapies in MS. This technique is complementary to conventional MRI and provides unique information on neuroinflammation and its modulation.
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Affiliation(s)
- Caroline Guglielmetti
- Department of Physical Therapy and Rehabilitation Science, University of California San Francisco, San Francisco, CA, USA.
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
| | - Christian Cordano
- Department of Neurology, Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, USA
| | - Chloé Najac
- Department of Radiology, C.J. Gorter MRI Center, Leiden University Medical Center, Leiden, The Netherlands
| | - Ari J Green
- Department of Neurology, Weill Institute for Neurosciences, University of California at San Francisco, San Francisco, CA, USA
- Department of Ophthalmology, University of California at San Francisco, CA, San Francisco, USA
| | - Myriam M Chaumeil
- Department of Physical Therapy and Rehabilitation Science, University of California San Francisco, San Francisco, CA, USA.
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
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Hyppönen V, Stenroos P, Nivajärvi R, Ardenkjaer-Larsen JH, Gröhn O, Paasonen J, Kettunen MI. Metabolism of hyperpolarised [1- 13 C]pyruvate in awake and anaesthetised rat brains. NMR IN BIOMEDICINE 2022; 35:e4635. [PMID: 34672399 DOI: 10.1002/nbm.4635] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 09/16/2021] [Accepted: 09/26/2021] [Indexed: 06/13/2023]
Abstract
The use of hyperpolarised 13 C pyruvate for nononcological neurological applications has not been widespread so far, possibly due to delivery issues limiting the visibility of metabolites. First proof-of-concept results have indicated that metabolism can be detected in human brain, and this may supersede the results obtained in preclinical settings. One major difference between the experimental setups is that preclinical MRI/MRS routinely uses anaesthesia, which alters both haemodynamics and metabolism. Here, we used hyperpolarised [1-13 C]pyruvate to compare brain metabolism in awake rats and under isoflurane, urethane or medetomidine anaesthesia. Spectroscopic [1-13 C]pyruvate time courses measured sequentially showed that pyruvate-to-bicarbonate and pyruvate-to-lactate labelling rates were lower in isoflurane animals than awake animals. An increased bicarbonate-to-lactate ratio was observed in the medetomidine group compared with other groups. The study shows that hyperpolarised [1-13 C]pyruvate experiments can be performed in awake rats, thus avoiding anaesthesia-related issues. The results suggest that haemodynamics probably dominate the observed pyruvate-to-metabolite labelling rates and area-under-time course ratios of referenced to pyruvate. On the other hand, the results obtained with medetomidine suggest that the ratios are also modulated by the underlying cerebral metabolism. However, the ratios between intracellular metabolites were unchanged in awake compared with isoflurane-anaesthetised rats.
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Affiliation(s)
- Viivi Hyppönen
- Kuopio Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Petteri Stenroos
- Kuopio Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Riikka Nivajärvi
- Kuopio Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jan Henrik Ardenkjaer-Larsen
- Center for Hyperpolarization in Magnetic Resonance, Department of Health Technology, Technical University of Denmark, Lyngby, Denmark
| | - Olli Gröhn
- Kuopio Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Jaakko Paasonen
- Kuopio Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Mikko I Kettunen
- Kuopio Biomedical Imaging Unit, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
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7
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19F MRI Imaging Strategies to Reduce Isoflurane Artifacts in In Vivo Images. Mol Imaging Biol 2021; 24:71-81. [PMID: 34671928 PMCID: PMC8760223 DOI: 10.1007/s11307-021-01653-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 11/20/2022]
Abstract
Purpose
Isoflurane (ISO) is the most commonly used preclinical inhalation anesthetic. This is a problem in 19F MRI of fluorine contrast agents, as ISO signals cause artifacts that interfere with unambiguous image interpretation and quantification; the two most attractive properties of heteronuclear MRI. We aimed to avoid these artifacts using MRI strategies that can be applied by any pre-clinical researcher. Procedures Three strategies to avoid ISO chemical shift displacement artifacts (CSDA) in 19F MRI are described and demonstrated with measurements of 19F-containing agents in phantoms and in vivo (n = 3 for all strategies). The success of these strategies is compared to a standard Rapid Acquisition with Relaxation Enhancement (RARE) sequence, with phantom and in vivo validation. ISO artifacts can successfully be avoided by (1) shifting them outside the region of interest using a narrow signal acquisition bandwidth, (2) suppression of ISO by planning a frequency-selective suppression pulse before signal acquisition or by (3) preventing ISO excitation with a 3D sequence with a narrow excitation bandwidth. Results All three strategies result in complete ISO signal avoidance (p < 0.0001 for all methods). Using a narrow acquisition bandwidth can result in loss of signal to noise ratio and distortion of the image, and a frequency-selective suppression pulse can be incomplete when B1-inhomogeneities are present. Preventing ISO excitation with a narrow excitation pulse in a 3D sequence yields the most robust results (relative SNR 151 ± 28% compared to 2D multislice methods, p = 0.006). Conclusion We optimized three easily implementable methods to avoid ISO signal artifacts and validated their performance in phantoms and in vivo. We make recommendation on the parameters that pre-clinical studies should report in their method section to make the used approach insightful.
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Hackett EP, Shah BR, Cheng B, LaGue E, Vemireddy V, Mendoza M, Bing C, Bachoo RM, Billingsley KL, Chopra R, Park JM. Probing Cerebral Metabolism with Hyperpolarized 13C Imaging after Opening the Blood-Brain Barrier with Focused Ultrasound. ACS Chem Neurosci 2021; 12:2820-2828. [PMID: 34291630 DOI: 10.1021/acschemneuro.1c00197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Transient disruption of the blood-brain barrier (BBB) with focused ultrasound (FUS) is an emerging clinical method to facilitate targeted drug delivery to the brain. The focal noninvasive disruption of the BBB can be applied to promote the local delivery of hyperpolarized substrates. In this study, we investigated the effects of FUS on imaging brain metabolism using two hyperpolarized 13C-labeled substrates in rodents: [1-13C]pyruvate and [1-13C]glycerate. The BBB is a rate-limiting factor for pyruvate delivery to the brain, and glycerate minimally passes through the BBB. First, cerebral imaging with hyperpolarized [1-13C]pyruvate resulted in an increase in total 13C signals (p = 0.05) after disrupting the BBB with FUS. Significantly higher levels of both [1-13C]lactate (lactate/total 13C signals, p = 0.01) and [13C]bicarbonate (p = 0.008) were detected in the FUS-applied brain region as compared to the contralateral FUS-unaffected normal-appearing brain region. The application of FUS without opening the BBB in a separate group of rodents resulted in comparable lactate and bicarbonate productions between the FUS-applied and the contralateral brain regions. Second, 13C imaging with hyperpolarized [1-13C]glycerate after opening the BBB showed increased [1-13C]glycerate delivery to the FUS-applied region (p = 0.04) relative to the contralateral side, and [1-13C]lactate production was consistently detected from the FUS-applied region. Our findings suggest that FUS accelerates the delivery of hyperpolarized molecules across the BBB and provides enhanced sensitivity to detect metabolic products in the brain; therefore, hyperpolarized 13C imaging with FUS may provide new opportunities to study cerebral metabolic pathways as well as various neurological pathologies.
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Affiliation(s)
- Edward P. Hackett
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Bhavya R. Shah
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Bingbing Cheng
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Radiology, The University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Evan LaGue
- Department of Chemistry and Biochemistry, California State University, Fullerton, Fullerton, California 92834, United States
| | - Vamsidihara Vemireddy
- Department of Internal Medicine, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Manuel Mendoza
- Department of Chemistry and Biochemistry, California State University, Fullerton, Fullerton, California 92834, United States
| | - Chenchen Bing
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Radiology, The University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Robert M. Bachoo
- Department of Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Harold C. Simmons Comprehensive Cancer Center, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Kelvin L. Billingsley
- Department of Chemistry and Biochemistry, California State University, Fullerton, Fullerton, California 92834, United States
| | - Rajiv Chopra
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
| | - Jae Mo Park
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Radiology, The University of Texas Southwestern Medical Center, Dallas, Texas 75390, United States
- Department of Electrical and Computer Engineering, The University of Texas at Dallas, Richardson, Texas 75080, United States
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In vivo detection of γ-glutamyl-transferase up-regulation in glioma using hyperpolarized γ-glutamyl-[1- 13C]glycine. Sci Rep 2020; 10:6244. [PMID: 32277103 PMCID: PMC7148357 DOI: 10.1038/s41598-020-63160-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 03/24/2020] [Indexed: 01/12/2023] Open
Abstract
Glutathione (GSH) is often upregulated in cancer, where it serves to mitigate oxidative stress. γ-glutamyl-transferase (GGT) is a key enzyme in GSH homeostasis, and compared to normal brain its expression is elevated in tumors, including in primary glioblastoma. GGT is therefore an attractive imaging target for detection of glioblastoma. The goal of our study was to assess the value of hyperpolarized (HP) γ-glutamyl-[1-13C]glycine for non-invasive imaging of glioblastoma. Nude rats bearing orthotopic U87 glioblastoma and healthy controls were investigated. Imaging was performed by injecting HP γ-glutamyl-[1-13C]glycine and acquiring dynamic 13C data on a preclinical 3T MR scanner. The signal-to-noise (SNR) ratios of γ-glutamyl-[1-13C]glycine and its product [1-13C]glycine were evaluated. Comparison of control and tumor-bearing rats showed no difference in γ-glutamyl-[1-13C]glycine SNR, pointing to similar delivery to tumor and normal brain. In contrast, [1-13C]glycine SNR was significantly higher in tumor-bearing rats compared to controls, and in tumor regions compared to normal-appearing brain. Importantly, higher [1-13C]glycine was associated with higher GGT expression and higher GSH levels in tumor tissue compared to normal brain. Collectively, this study demonstrates, to our knowledge for the first time, the feasibility of using HP γ-glutamyl-[1-13C]glycine to monitor GGT expression in the brain and thus to detect glioblastoma.
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Le Page LM, Guglielmetti C, Taglang C, Chaumeil MM. Imaging Brain Metabolism Using Hyperpolarized 13C Magnetic Resonance Spectroscopy. Trends Neurosci 2020; 43:343-354. [PMID: 32353337 DOI: 10.1016/j.tins.2020.03.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/28/2020] [Accepted: 03/08/2020] [Indexed: 12/28/2022]
Abstract
Aberrant metabolism is a key factor in many neurological disorders. The ability to measure such metabolic impairment could lead to improved detection of disease progression, and development and monitoring of new therapeutic approaches. Hyperpolarized 13C magnetic resonance spectroscopy (MRS) is a developing imaging technique that enables non-invasive measurement of enzymatic activity in real time in living organisms. Primarily applied in the fields of cancer and cardiac disease so far, this metabolic imaging method has recently been used to investigate neurological disorders. In this review, we summarize the preclinical research developments in this emerging field, and discuss future prospects for this exciting technology, which has the potential to change the clinical paradigm for patients with neurological disorders.
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Affiliation(s)
- Lydia M Le Page
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Caroline Guglielmetti
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Celine Taglang
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Myriam M Chaumeil
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA.
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