1
|
Takakusagi Y, Kobayashi R, Saito K, Kishimoto S, Krishna MC, Murugesan R, Matsumoto KI. EPR and Related Magnetic Resonance Imaging Techniques in Cancer Research. Metabolites 2023; 13:metabo13010069. [PMID: 36676994 PMCID: PMC9862119 DOI: 10.3390/metabo13010069] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/04/2023] Open
Abstract
Imaging tumor microenvironments such as hypoxia, oxygenation, redox status, and/or glycolytic metabolism in tissues/cells is useful for diagnostic and prognostic purposes. New imaging modalities are under development for imaging various aspects of tumor microenvironments. Electron Paramagnetic Resonance Imaging (EPRI) though similar to NMR/MRI is unique in its ability to provide quantitative images of pO2 in vivo. The short electron spin relaxation times have been posing formidable challenge to the technology development for clinical application. With the availability of the narrow line width trityl compounds, pulsed EPR imaging techniques were developed for pO2 imaging. EPRI visualizes the exogenously administered spin probes/contrast agents and hence lacks the complementary morphological information. Dynamic nuclear polarization (DNP), a phenomenon that transfers the high electron spin polarization to the surrounding nuclear spins (1H and 13C) opened new capabilities in molecular imaging. DNP of 13C nuclei is utilized in metabolic imaging of 13C-labeled compounds by imaging specific enzyme kinetics. In this article, imaging strategies mapping physiologic and metabolic aspects in vivo are reviewed within the framework of their application in cancer research, highlighting the potential and challenges of each of them.
Collapse
Affiliation(s)
- Yoichi Takakusagi
- Quantum Hyperpolarized MRI Research Team, Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba 263-8555, Japan
- Department of Quantum Life Science, Graduate School of Science, Chiba University, Chiba 265-8522, Japan
- Correspondence: (Y.T.); (K.-i.M.); Tel.: +81-43-382-4297 (Y.T.); +81-43-206-3123 (K.-i.M.)
| | - Ryoma Kobayashi
- Quantum Hyperpolarized MRI Research Team, Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba 263-8555, Japan
| | - Keita Saito
- Quantum Hyperpolarized MRI Research Team, Institute for Quantum Life Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba 263-8555, Japan
| | - Shun Kishimoto
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1002, USA
| | - Murali C. Krishna
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-1002, USA
| | - Ramachandran Murugesan
- Karpaga Vinayaga Institute of Medical Sciences and Research Center, Palayanoor (PO), Chengalpattu 603308, India
| | - Ken-ichiro Matsumoto
- Quantitative RedOx Sensing Group, Department of Radiation Regulatory Science Research, National Institute of Radiological Sciences, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-Ku, Chiba 263-8555, Japan
- Correspondence: (Y.T.); (K.-i.M.); Tel.: +81-43-382-4297 (Y.T.); +81-43-206-3123 (K.-i.M.)
| |
Collapse
|
2
|
Affiliation(s)
- Kazuyuki Ishii
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan
| |
Collapse
|
3
|
Yasukawa K, Shigemi R, Kanbe T, Mutsumoto Y, Oda F, Ichikawa K, Yamada KI, Tun X, Utsumi H. In Vivo Imaging of the Intra- and Extracellular Redox Status in Rat Stomach with Indomethacin-Induced Gastric Ulcers Using Overhauser-Enhanced Magnetic Resonance Imaging. Antioxid Redox Signal 2019; 30:1147-1161. [PMID: 29631421 DOI: 10.1089/ars.2017.7336] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
AIMS Repeated use of nonsteroidal anti-inflammatory drugs can induce changes in the redox status, including production of reactive oxygen species (ROS), but the specific details of these changes remain unknown. Overhauser-enhanced magnetic resonance imaging (OMRI) has been used in vivo to monitor the redox status in several diseases and map tissue oxygen concentrations. We monitored the intra- and extracellular redox status in the stomach of rats with indomethacin-induced gastric ulcers using OMRI and investigated the relationship with gastric mucosal damage. RESULTS One hour after oral administration of indomethacin (30 mg/kg), OMRI measurements in the stomach were made following nitroxyl probe administration. OMRI with the membrane-permeable nitroxyl probe, 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPOL), demonstrated a redox change toward oxidation, which was reversed by a membrane-permeable antioxidant. Conversely, imaging with the impermeable probe, 4-trimethylammonium-2,2,6,6-tetramethyl-piperidine-1-oxyl (CAT-1), demonstrated little redox change. Redox imbalance imaging of a live rat stomach with indomethacin-induced gastric ulcers was produced by dual imaging of 15N-labeled TEMPOL and 14N-labeled CAT-1, in addition to imaging with another membrane-permeable 15N-labeled probe, 3-methoxycarbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL), and 14N-labeled CAT-1. Pretreatment with MC-PROXYL suppressed gastric mucosal damage, whereas pretreatment with CAT-1 did not suppress ulcer formation. INNOVATION OMRI combined with a dual probe is a less invasive imaging technique for evaluation of intracellular ROS production contributing to the formation of gastric ulcers in the stomach of indomethacin-treated rats, which cannot be done with other methods. CONCLUSION This method may be a very powerful tool for characterizing the pathogenesis of various diseases and may have medical applications.
Collapse
Affiliation(s)
- Keiji Yasukawa
- 1 Laboratory of Advanced Pharmacology, Daiichi University of Pharmacy, Fukuoka, Japan.,2 Physical Chemistry for Life Science Laboratory, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.,3 Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan
| | - Ryota Shigemi
- 2 Physical Chemistry for Life Science Laboratory, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Tomomi Kanbe
- 2 Physical Chemistry for Life Science Laboratory, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Yusaku Mutsumoto
- 2 Physical Chemistry for Life Science Laboratory, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Fumiko Oda
- 2 Physical Chemistry for Life Science Laboratory, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Kazuhiro Ichikawa
- 3 Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan
| | - Ken-Ichi Yamada
- 2 Physical Chemistry for Life Science Laboratory, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | - Xin Tun
- 4 Division of Host Defense, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Hideo Utsumi
- 5 School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan
| |
Collapse
|
4
|
Bonnitcha P, Grieve S, Figtree G. Clinical imaging of hypoxia: Current status and future directions. Free Radic Biol Med 2018; 126:296-312. [PMID: 30130569 DOI: 10.1016/j.freeradbiomed.2018.08.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 07/30/2018] [Accepted: 08/14/2018] [Indexed: 12/20/2022]
Abstract
Tissue hypoxia is a key feature of many important causes of morbidity and mortality. In pathologies such as stroke, peripheral vascular disease and ischaemic heart disease, hypoxia is largely a consequence of low blood flow induced ischaemia, hence perfusion imaging is often used as a surrogate for hypoxia to guide clinical diagnosis and treatment. Importantly, ischaemia and hypoxia are not synonymous conditions as it is not universally true that well perfused tissues are normoxic or that poorly perfused tissues are hypoxic. In pathologies such as cancer, for instance, perfusion imaging and oxygen concentration are less well correlated, and oxygen concentration is independently correlated to radiotherapy response and overall treatment outcomes. In addition, the progression of many diseases is intricately related to maladaptive responses to the hypoxia itself. Thus there is potentially great clinical and scientific utility in direct measurements of tissue oxygenation. Despite this, imaging assessment of hypoxia in patients is rarely performed in clinical settings. This review summarises some of the current methods used to clinically evaluate hypoxia, the barriers to the routine use of these methods and the newer agents and techniques being explored for the assessment of hypoxia in pathological processes.
Collapse
Affiliation(s)
- Paul Bonnitcha
- Northern and Central Clinical Schools, Faculty of Medicine, Sydney University, Sydney, NSW 2006, Australia; Chemical Pathology Department, NSW Health Pathology, Royal Prince Alfred Hospital, Camperdown, NSW 2050, Australia; Kolling Institute of Medical Research, University of Sydney, St Leonards, New South Wales 2065, Australia.
| | - Stuart Grieve
- Sydney Translational Imaging Laboratory, Heart Research Institute, Charles Perkins Centre and Sydney Medical School, University of Sydney, NSW 2050, Australia
| | - Gemma Figtree
- Kolling Institute of Medical Research, University of Sydney, St Leonards, New South Wales 2065, Australia; Cardiology Department, Royal North Shore Hospital, St Leonards, New South Wales 2065, Australia
| |
Collapse
|
5
|
Yokoi T, Ishii K. Dependence of phthalocyanine-based fluorescence on albumin structure: A fluorescent probe for ascorbic acid. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2018.05.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
6
|
In vivo fluorescence bioimaging of ascorbic acid in mice: Development of an efficient probe consisting of phthalocyanine, TEMPO, and albumin. Sci Rep 2018; 8:1560. [PMID: 29367703 PMCID: PMC5784034 DOI: 10.1038/s41598-018-19762-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 01/09/2018] [Indexed: 01/08/2023] Open
Abstract
After a groundbreaking study demonstrated that a high dose of ascorbic acid selectively kills cancer cells, the compound has been tested in the clinic against various forms of cancers, with some success. However, in vivo tracing of intravenously injected ascorbic acid has not been achieved. Herein, we successfully imaged ascorbic acid intravenously injected into mice based on the discovery of a novel, highly sensitive, and appropriately selective fluorescent probe consisting of silicon phthalocyanine (SiPc) and two 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) radicals, i.e., R2c. The radicals in this R2c were encapsulated in dimeric bovine serum albumin, and the sensitivity was >100-fold higher than those of other R2c-based probes. Ascorbic acid intravenously injected into mice was efficiently transported to the liver, heart, lung, and cholecyst. The present results provide opportunities to advance the use of ascorbic acid as cancer therapy.
Collapse
|
7
|
Utsumi H, Hyodo F. Free Radical Imaging Using In Vivo Dynamic Nuclear Polarization-MRI. Methods Enzymol 2015; 564:553-71. [DOI: 10.1016/bs.mie.2015.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
8
|
Hyodo F, Ito S, Yasukawa K, Kobayashi R, Utsumi H. Simultaneous and spectroscopic redox molecular imaging of multiple free radical intermediates using dynamic nuclear polarization-magnetic resonance imaging. Anal Chem 2014; 86:7234-8. [PMID: 25036767 DOI: 10.1021/ac502150x] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Redox reactions that generate free radical intermediates are essential to metabolic processes. However, their intermediates can produce reactive oxygen species, which may promote diseases related to oxidative stress. We report here the use of dynamic nuclear polarization-magnetic resonance imaging (DNP-MRI) to conduct redox molecular imaging. Using DNP-MRI, we obtained simultaneous images of free radical intermediates generated from the coenzyme Q10 (CoQ10), flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD) involved in the mitochondrial electron transport chain as well as the radicals derived from vitamins E and K1. Each of these free radicals was imaged in real time in a phantom comprising a mixture of free radicals localized in either lipophilic or aqueous environments. Changing the frequency of electron spin resonance (ESR) irradiation also allowed each of the radical species to be distinguished in the spectroscopic images. This study is the first to report the spectroscopic DNP-MRI imaging of free radical intermediates that are derived from endogenous species involved in metabolic processes.
Collapse
Affiliation(s)
- Fuminori Hyodo
- Innovation Center for Medical Redox Navigation, Kyushu University , 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | | | | | | | | |
Collapse
|
9
|
Utsumi H. Novel Redox Molecular Imaging “ReMI” with Dual Magnetic Resonance. YAKUGAKU ZASSHI 2013; 133:803-14. [DOI: 10.1248/yakushi.13-00139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hideo Utsumi
- Innovation Center for Medical Redox Navigation, Kyushu University
| |
Collapse
|
10
|
Elas M, Ichikawa K, Halpern HJ. Oxidative stress imaging in live animals with techniques based on electron paramagnetic resonance. Radiat Res 2012; 177:514-23. [PMID: 22348251 DOI: 10.1667/rr2668.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Oxidative stress has been the object of considerable biological and biochemical investigation. Quantification has been difficult although the quantitative level of products of biological oxidations in tissues and tissue products has emerged as a widely used technique. The relationship between these products and the amount of oxidative stress is less clear. Imaging oxidative stress with electron paramagnetic resonance related magnetic resonance imaging, while not addressing the specific issue of quantification of initiating events, focuses on the anatomic specific location of the oxidative stress. Moreover, the relative quantification of oxidative stress of one location against another is possible, sharpening our understanding of oxidative stress. This promises to improve our understanding of oxidative stress and its deleterious consequences and enhance our understanding of the effectiveness of interventions to modulate oxidative stress and its consequences.
Collapse
Affiliation(s)
- Martyna Elas
- Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois, USA
| | | | | |
Collapse
|
11
|
Ishii K, Kubo K, Sakurada T, Komori K, Sakai Y. Phthalocyanine-based fluorescence probes for detecting ascorbic acid: phthalocyaninatosilicon covalently linked to TEMPO radicals. Chem Commun (Camb) 2011; 47:4932-4. [DOI: 10.1039/c1cc10817d] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
12
|
Duca G, Secara N, Duca D. Physical Methods of Fast Reactions Investigation. CHEMISTRY JOURNAL OF MOLDOVA 2008. [DOI: 10.19261/cjm.2008.03(1).15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
This review presents the basic concepts of the methods used for investigation of fast reactions kinetics, such as: flow methods, with particular emphasis on the stopped-flow approach, NMR, ESR, electrochemical methods, with particular emphasis on the time resolved Fourier Transform electrochemical impedance spectroscopy, flash photolysis, and several others. It offers a brief description of fast reactions commonly encountered in chemical systems, providing an insight into the possibilities of performing kinetic investigations of such reaction systems.
Collapse
|
13
|
Czechowski T, Krzyminiewski R, Jurga J, Chlewicki W. Two-dimensional imaging of two types of radicals by the CW-EPR method. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2008; 190:52-59. [PMID: 17977763 DOI: 10.1016/j.jmr.2007.09.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2007] [Revised: 09/24/2007] [Accepted: 09/27/2007] [Indexed: 05/25/2023]
Abstract
The CW-EPR method of image reconstruction is based on sample rotation in a magnetic field with a constant gradient (50 G/cm). In order to obtain a projection (radical density distribution) along a given direction, the EPR spectra are recorded with and without the gradient. Deconvolution, then gives the distribution of the spin density. Projection at 36 different angles gives the information that is necessary for reconstruction of the radical distribution. The problem becomes more complex when there are at least two types of radicals in the sample, because the deconvolution procedure does not give satisfactory results. We propose a method to calculate the projections for each radical, based on iterative procedures. The images of density distribution for each radical obtained by our procedure have proved that the method of deconvolution, in combination with iterative fitting, provides correct results. The test was performed on a sample of polymer PPS Br 111 (p-phenylene sulphide) with glass fibres and minerals. The results indicated a heterogeneous distribution of radicals in the sample volume. The images obtained were in agreement with the known shape of the sample.
Collapse
Affiliation(s)
- Tomasz Czechowski
- Medical Physics Department, Institute of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan, Poland.
| | | | | | | |
Collapse
|
14
|
Matsumoto KI, Subramanian S, Murugesan R, Mitchell JB, Krishna MC. Spatially resolved biologic information from in vivo EPRI, OMRI, and MRI. Antioxid Redox Signal 2007; 9:1125-41. [PMID: 17571957 DOI: 10.1089/ars.2007.1638] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
EPR spectroscopy can give biologically important information, such as tissue redox status, pO2, pH, and microviscosity, based on variation of EPR spectral characteristics (i.e., intensity, linewidth, hyperfine splitting, and spectral shape of free radical probes. EPR imaging (EPRI) can obtain 1D-3D spatial distribution of such spectral components using several combinations of magnetic field gradients. Overhauser enhanced MRI (OMRI) is a double-resonance technique of electron and nuclear spins. Because the Overhauser enhancement depends on transverse relaxation rate of the electron spin, OMRI can provide pO2 information indirectly, along with a high-resolution MR image. MRI can also indirectly detect paramagnetic behaviors of free radical contrast agents. Imaging techniques and applications relating to paramagnetic species (i.e., EPRI, OMRI, and MRI) have the potential to obtain maximally 5D information (i.e., 3D spatial + 1D spectral + 1D temporal dimensions, theoretically). To obtain suitable dimensionality, several factors, such as the EPR spectral information, spatial resolution, temporal resolution, will have to be taken into account. For this review, the EPRI, OMRI, and MRI applications for the study biological systems were evaluated for researchers to apply the method of choice and the mode of measurements to specific experimental systems.
Collapse
Affiliation(s)
- Ken-ichiro Matsumoto
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | | | | | | | | |
Collapse
|
15
|
Matsumoto KI, Narazaki M, Ikehira H, Anzai K, Ikota N. Comparisons of EPR imaging and T1-weighted MRI for efficient imaging of nitroxyl contrast agents. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2007; 187:155-62. [PMID: 17433743 DOI: 10.1016/j.jmr.2007.03.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 01/12/2007] [Accepted: 03/03/2007] [Indexed: 05/14/2023]
Abstract
The resolution and signal to noise ratio of EPR imaging and T(1)-weighted MRI were compared using an identical phantom. Several solutions of nitroxyl contrast agents with different EPR spectral shapes were tested. The feasibility of T(1)-weighted MRI to detect nitroxyl contrast agents was described. T(1)-weighted MRI can detect nitroxyl contrast agents with a complicated EPR spectrum easier and quicker; however, T(1)-weighted MRI has less quantitative ability especially for lipophilic nitroxyl contrast agents, because T(1)-relaxivity, i.e. accessibility to water, is affected by the hydrophilic/hydrophobic micro-environment of a nitroxyl contrast agent. The less quantitative ability of T(1)-weighted MRI may not be a disadvantage of redox imaging, which obtains reduction rate of a nitroxyl contrast. Therefore, T(1)-weighted MRI has a great advantage to check the pharmacokinetics of newly modified and/or designed nitroxyl contrast agents.
Collapse
Affiliation(s)
- Ken-ichiro Matsumoto
- Radiation Modifier Research Team, Heavy-Ion Radiobiology Research Group, Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555, Japan.
| | | | | | | | | |
Collapse
|
16
|
Matsumoto S, Yamada K, Hirata H, Yasukawa K, Hyodo F, Ichikawa K, Utsumi H. Advantageous application of a surface coil to EPR irradiation in overhauser-enhanced MRI. Magn Reson Med 2007; 57:806-11. [PMID: 17390363 DOI: 10.1002/mrm.21198] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The present study describes the advantageous application of a surface coil to electron paramagnetic resonance (EPR) irradiation in Overhauser-enhanced MRI (OMRI). OMRI is a double-resonance method for imaging free radicals based on the Overhauser effect. Proton NMR images are recorded without and with EPR irradiation of the free radical resonance, which results in a difference proton image that shows signal enhancement in spatial regions that contain the free radical. To obtain good signal enhancement in OMRI, very high RF power and a long EPR irradiation time are required. To improve sensitivity and shorten the image acquisition time, especially for localized (and topical) applications, we developed and tested a surface-coil-type EPR irradiation coil. Theoretical calculations and experimental data showed that EPR irradiation through the surface coil could ameliorate the localized Overhauser enhancement, which was related to the ratio of B(1) surface coil/B(1) volume coil in the region of interest (ROI), as expected. The increased sensitivity could also be converted into a shortened EPR irradiation time, resulting in fast data acquisition. For biomedical applications, the use of a surface coil (as opposed to a conventional volume coil) could decrease the total RF power deposition in the sample required to obtain the same Overhauser enhancement in the ROI.
Collapse
Affiliation(s)
- Shingo Matsumoto
- Department of Biofunctional Science, Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | | | | | | | | | | | | |
Collapse
|
17
|
|
18
|
Matsumoto KI, Kawai S, Chignell CF, Utsumi H. Location of anthralin radical generation in mouse skin by UV-A irradiation: An estimation using microscopic EPR spectral-spatial imaging. Magn Reson Med 2006; 55:738-42. [PMID: 16528709 DOI: 10.1002/mrm.20862] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In vivo location of the anthralin radical generated in mouse skin by ultraviolet A (UV-A) irradiation was estimated by microscopic electron paramagnetic resonance (EPR) spectral-spatial imaging. An X-band EPR spectrometer equipped with specially designed high-power imaging coils and a TE-mode cavity was employed. The maximum field gradient used in this study was 6.77 mT/mm. Anthralin was applied to the dorsal skin of live mice, which were then exposed to UV-A irradiation. A broad singlet EPR spectrum (peak-to-peak line width = 0.6 mT and g = 2.004) was obtained. Microscopic EPR spectral-spatial imaging of the skin tissue showed that the anthralin radical was located mainly in the epidermis (27 microm from the skin surface). This result was consistent with the finding that the proportions of the radical in the dermis and epidermis were about 15% and 85%, respectively.
Collapse
Affiliation(s)
- Ken-ichiro Matsumoto
- Department of Biofunction Science, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
| | | | | | | |
Collapse
|
19
|
Sonta T, Inoguchi T, Matsumoto S, Yasukawa K, Inuo M, Tsubouchi H, Sonoda N, Kobayashi K, Utsumi H, Nawata H. In vivo imaging of oxidative stress in the kidney of diabetic mice and its normalization by angiotensin II type 1 receptor blocker. Biochem Biophys Res Commun 2005; 330:415-22. [PMID: 15796899 DOI: 10.1016/j.bbrc.2005.02.174] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2005] [Indexed: 11/18/2022]
Abstract
This study was undertaken to evaluate oxidative stress in the kidney of diabetic mice by electron spin resonance (ESR) imaging technique. Oxidative stress in the kidney was evaluated as organ-specific reducing activity with the signal decay rates of carbamoyl-PROXYL probe using ESR imaging. The signal decay rates were significantly faster in corresponding image pixels of the kidneys of streptozotocin-induced diabetic mice than in those of controls. This technique further demonstrated that administration of angiotensin II type 1 receptor blocker (ARB), olmesartan (5 mg/kg), completely restored the signal decay rates in the diabetic kidneys to control values. In conclusion, this study provided for the first time the in vivo evidence for increased oxidative stress in the kidneys of diabetic mice and its normalization by ARB as evaluated by ESR imaging. This technique would be useful as a means of further elucidating the role of oxidative stress in diabetic nephropathy.
Collapse
Affiliation(s)
- Toshiyo Sonta
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Ishii K, Takayanagi A, Shimizu S, Abe H, Sogawa K, Kobayashi N. In vitro photodynamic effects of phthalocyaninatosilicon covalently linked to 2,2,6,6-tetramethyl-1-piperidinyloxy radicals on cancer cells. Free Radic Biol Med 2005; 38:920-7. [PMID: 15749388 DOI: 10.1016/j.freeradbiomed.2004.12.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2004] [Revised: 10/15/2004] [Accepted: 12/10/2004] [Indexed: 11/18/2022]
Abstract
In this paper, we have investigated the ability to sensitize the phototoxicity toward HeLa cells in vitro, of tetra-tert-butylphthalocyaninatosilicon (SiPc) covalently linked to one or two 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) radicals (R1c or R2c), which are shown as photosensitizers efficiently producing singlet oxygen (1Delta(g)). Addition of R1c or R2c encapsulated in liposomes to cultures, followed by irradiation with a 680-nm dye laser, resulted in a highly significant phototoxicity toward HeLa cells, in contrast to negligible phototoxicity observed with (dihydroxy)SiPc (R0). EPR measurements indicate that R1c and R2c exist in some degree as nitroxide radicals even in HeLa cells. Electronic absorption spectra indicate that the degree of aggregation increases in the order R2c<R1c<R0. Thus, the high phototoxicity of R1c and R2c toward HeLa cells is reasonably interpreted by both the large singlet oxygen yield and the inhibition of aggregation due to the bulky TEMPO radicals. This increase in photodynamic effect on HeLa cells is an unusual and important example for increasing the photobiological reaction yields using paramagnetic radicals.
Collapse
Affiliation(s)
- Kazuyuki Ishii
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | | | | | | | | | | |
Collapse
|
21
|
Matsumoto KI, Yahiro T, Yamada KI, Utsumi H. In vivo EPR spectroscopic imaging for a liposomal drug delivery system. Magn Reson Med 2005; 53:1158-65. [PMID: 15844139 DOI: 10.1002/mrm.20460] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We used the membrane-impermeable nitroxyl radical 4-trimethylammonium-2,2,6,6-tetramethylpiperidine-1-oxyliodide (CAT-1) as a model drug encapsulated in liposomes in order to separately map the 2D distribution of both liposomal-encapsulated CAT-1 and free CAT-1. Phantoms were prepared with a CAT-1 solution and a liposomal CAT-1 suspension. Spectral-spatial images were obtained along several polar-arranged spatial axes through the phantom. The 1D spatial distributions (projections) of each signal component, reflecting the concentration of CAT-1, were then extracted from the spectral-spatial images. 2D EPR images of liposomal-encapsulated CAT-1 and free CAT-1 were separately reconstructed from the resulting projection data sets. 2D mapping of each component exhibited good agreement with respect to the phantom. Separate maps were generated from separate injections of free CAT-1 and liposomal CAT-1 injected into the femoral muscle of a living mouse. The EPR signal of the free CAT-1 gradually decreased during data acquisition. Because of this decay, we calibrated the image intensity by extrapolating the signal intensity to that detected at the beginning of data sampling. Both the position and size of the individual images were in very good agreement with those of the mouse thigh obtained by MRI.
Collapse
Affiliation(s)
- Ken-ichiro Matsumoto
- Department of Biofunction Science, Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan
| | | | | | | |
Collapse
|
22
|
Matsumoto KI, Chandrika B, Lohman JAB, Mitchell JB, Krishna MC, Subramanian S. Application of continuous-wave EPR spectral-spatial image reconstruction techniques for in vivo oxymetry: Comparison of projection reconstruction and constant-time modalities. Magn Reson Med 2003; 50:865-74. [PMID: 14523974 DOI: 10.1002/mrm.10594] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In this study we report the application of continuous-wave (CW) electron paramagnetic resonance (EPR) constant-time spectral spatial imaging (CTSSI) for in vivo oxymetry. 2D and 3D SSI studies of a phantom and live mice were carried out using projection reconstruction (PR) and constant-time (CT) modalities using a CW-EPR spectrometer/imager operating at 300 MHz frequency. Distortion of line shape, which is inherent in the PR method, was minimized by the CTSSI modality. It was also found that CTSSI offers improved noise reduction, restores a smoother line shape, and gives high convergence of estimated values. Spatial resolution was also improved by CTSSI, although fundamental spectral line-width broadening was observed. Although additional corrections are required for accurate estimations of spectral line width, CTSSI was able to demonstrate distinct differences in oxygen tension between a tumor and the normal legs of a C3H mouse. The PR method, on the other hand, was unable to make such a distinction unequivocally with the triarylmethyl spin probes. CTSSI promises to be a more suitable method for quantitative in vivo oxymetric studies using radiofrequency EPR imaging (EPRI).
Collapse
Affiliation(s)
- Ken-ichiro Matsumoto
- Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | | | | | | | | | |
Collapse
|
23
|
In vivo electron spin resonance-computed tomography/nitroxyl probe technique for non-invasive analysis of oxidative injuries. Arch Biochem Biophys 2003; 416:1-8. [PMID: 12859975 DOI: 10.1016/s0003-9861(03)00285-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Free radicals are widely recognized as harmful chemical species in oxidative tissue injury. However, there have been no satisfying methods to visualize free radicals in vivo non-invasively with information of their localization and amount. In vivo electron spin resonance (ESR) spectroscopy was recently developed to measure free radicals generated in rodents. Several kinds of stable nitroxyl radicals were used as spin probes to detect free radicals. ESR signal intensities reflecting the accumulation of nitroxyl probes in each organ decreases time-dependently and reduction decay rates are increased in the presence of free radicals. Such increase in signal decay rates is suppressed by prior administration of antioxidants or antioxidant enzymes. Thus, in vivo ESR techniques are useful in estimating not only in vivo free radical reactions but also the effects of antioxidants, and furthermore, in combination with other tomographic techniques, permits non-invasive localization of free radicals. Application of this technique to animal models will be described.
Collapse
|
24
|
Abstract
A growing number of studies suggest a key role of nitric oxide (NO) derived from the inducible NO synthase (iNOS) isoform as a signalling molecule leading to acute organ transplant rejection. Current theory suggests that NO targets certain tissue proteins for nitrosylation or nitration leading to inhibition of enzyme/protein function and to cell death via apoptosis. Gene expression of iNOS and formation of nitrotyrosine residues have been confirmed in biopsies of rejecting grafts in humans. Experimental attempts to delay graft rejection by treatment with iNOS enzyme inhibitors have yielded conflicting results. An alternative strategy to alter rejection mediated by NO is to scavenge and/or neutralise the actions of excess NO, thereby by-passing the inhibition of iNOS enzyme activity. This review summarises recent laboratory evidence that new experimental NO scavengers/neutralisers have potential value to prolong graft survival. To date, various metal-based NO scavenging/neutralising compounds have been shown to enhance cardiac allograft survival in the absence of immunosuppression. When used in combination with low-dose cyclosporin, these agents produce a synergistic action to enhance graft survival or even to produce "permanent graft survival" under certain prolonged drug regimens. A portion of this benefit may be accounted for by the property of some of these compounds to display immunosuppressant and anti-inflammatory activity in vivo. These properties are based on findings including the following: (i) attenuating cell infiltration into the graft; (ii) attenuating activation of NFkappaB (a transcription factor important for upregulation of various inflammatory genes); (iii) attenuating cyclin D3 gene expression (a marker of cell proliferation; (iv) antagonising autoimmune activation (as determined by attenuated cytokine gene expression in splenocytes isolated from treated animals but stimulated for several days ex vivo in mixed lymphocyte cultures).
Collapse
Affiliation(s)
- Galen M Pieper
- Division of Transplant Surgery, Medical College of Wisconsin, 9200 West Wisconsin Avenue, Milwaukee, WI 53226, USA.
| | | | | |
Collapse
|
25
|
Utsumi H, Sano H, Naruse M, Matsumoto KI, Ichikawa K, Oi T. Nitroxyl probes for brain research and their application to brain imaging. Methods Enzymol 2002; 352:494-506. [PMID: 12125374 DOI: 10.1016/s0076-6879(02)52043-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- Hideo Utsumi
- Laboratory of Biofunction Analysis, Graduate School of Pharmaceutical Sciences, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan
| | | | | | | | | | | |
Collapse
|
26
|
Affiliation(s)
- Tetsuo Nagano
- Graduate School of Pharmacological Sciences, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | | |
Collapse
|