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Hamilton KE, Bouwer MF, Louters LL, Looyenga BD. Cellular binding and uptake of fluorescent glucose analogs 2-NBDG and 6-NBDG occurs independent of membrane glucose transporters. Biochimie 2021; 190:1-11. [PMID: 34224807 DOI: 10.1016/j.biochi.2021.06.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 06/16/2021] [Accepted: 06/30/2021] [Indexed: 02/05/2023]
Abstract
The classical methods for determining glucose uptake rates in living cells involve the use of isotopically labeled 2-deoxy-d-glucose or 3-O-methyl-d-glucose, which enter cells via well-characterized membrane transporters of the SLC2A and SLC5A families, respectively. These classical methods, however, are increasingly being displaced by high-throughput assays that utilize fluorescent analogs of glucose. Among the most commonly used of these analogs are 2-NBDG and 6-NBDG, which contain a bulky 7-nitro-2,1,3-benzoxadiazol-4-yl-amino moiety in place of a hydroxy group on d-glucose. This fluorescent group significantly alters both the size and shape of these molecules compared to glucose, calling into question whether they actually enter cells by the same transport mechanisms. In this study, we took advantage of the well-defined glucose uptake mechanism of L929 murine fibroblasts, which rely exclusively on the Glut1/Slc2a1 membrane transporter. We demonstrate that neither pharmacologic inhibition of Glut1 nor genetic manipulation of its expression has a significant impact on the binding or uptake of 2-NBDG or 6-NBDG by L929 cells, though both approaches significantly impact [3H]-2-deoxyglucose uptake rates. Together these data indicate that 2-NBDG and 6-NBDG can bind and enter mammalian cells by transporter-independent mechanisms, which calls into question their utility as an accurate proxy for glucose transport.
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Affiliation(s)
- Kathryn E Hamilton
- Calvin University, Department of Chemistry & Biochemistry, 1726 Knollcrest Circle SE, Grand Rapids, MI 49546, USA
| | - Miranda F Bouwer
- Calvin University, Department of Chemistry & Biochemistry, 1726 Knollcrest Circle SE, Grand Rapids, MI 49546, USA
| | - Larry L Louters
- Calvin University, Department of Chemistry & Biochemistry, 1726 Knollcrest Circle SE, Grand Rapids, MI 49546, USA
| | - Brendan D Looyenga
- Calvin University, Department of Chemistry & Biochemistry, 1726 Knollcrest Circle SE, Grand Rapids, MI 49546, USA.
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Zhang X, Zhu S, Li Y, Zhan Y, Chen X, Kang F, Wang J, Cao X. Gamma rays excited radioluminescence tomographic imaging. Biomed Eng Online 2018; 17:45. [PMID: 29690883 PMCID: PMC5916826 DOI: 10.1186/s12938-018-0480-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 04/18/2018] [Indexed: 11/26/2022] Open
Abstract
Background Radionuclide-excited luminescence imaging is an optical radionuclide imaging strategy to reveal the distributions of radioluminescent nanophosphors (RLNPs) inside small animals, which uses radioluminescence emitted from RLNPs when excited by high energy rays such as gamma rays generated during the decay of radiotracers used in clinical nuclear medicine imaging. Currently, there is no report of tomographic imaging based on radioluminescence. Methods In this paper, we proposed a gamma rays excited radioluminescence tomography (GRLT) to reveal three-dimensional distributions of RLNPs inside a small animal using radioluminescence through image reconstruction from surface measurements of radioluminescent photons using an inverse algorithm. The diffusion equation was employed to model propagations of radioluminescent photons in biological tissues with highly scattering and low absorption characteristics. Results Phantom and artificial source-implanted mouse model experiments were employed to test the feasibility of GRLT, and the results demonstrated that the ability of GRLT to reveal the distribution of RLNPs such as Gd2O2S:Tb using the radioluminescent signals when excited by gamma rays produced from 99mTc. Conclusions With the emerging of targeted RLNPs, GRLT can provide new possibilities for in vivo and noninvasive examination of biological processes at cellular levels. Especially, combining with Cerenkov luminescence imaging, GRLT can achieve dual molecular information of RLNPs and nuclides using single optical imaging technology.
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Affiliation(s)
- Xuanxuan Zhang
- Engineering Research Center of Molecular and Neuro Imaging of the Ministry of Education & School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China
| | - Shouping Zhu
- Engineering Research Center of Molecular and Neuro Imaging of the Ministry of Education & School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China
| | - Yang Li
- Engineering Research Center of Molecular and Neuro Imaging of the Ministry of Education & School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China
| | - Yonghua Zhan
- Engineering Research Center of Molecular and Neuro Imaging of the Ministry of Education & School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China
| | - Xueli Chen
- Engineering Research Center of Molecular and Neuro Imaging of the Ministry of Education & School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China
| | - Fei Kang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Jing Wang
- Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, Shaanxi, China
| | - Xu Cao
- Engineering Research Center of Molecular and Neuro Imaging of the Ministry of Education & School of Life Science and Technology, Xidian University, Xi'an, 710071, Shaanxi, China.
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Guo S, Yang Y, Yang Z, You H, Shi Y, Hu Z, Meng Z, Xiao J. Improving myocardial fractional flow reserve in coronary atherosclerosis via CX37 gene silence: a preclinical validation study in pigs. Interact Cardiovasc Thorac Surg 2018; 26:139-145. [PMID: 29049831 DOI: 10.1093/icvts/ivx218] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 05/30/2017] [Indexed: 12/16/2023] Open
Abstract
OBJECTIVES The purpose of this study was to evaluate the effect of CX37 gene silence on myocardial fractional flow reserve (FFR). METHODS A total of 90 male pigs were randomly divided into saline, mock and 3 different doses (5, 10 and 20 µl) of CX37 viral suspension groups that could induce coronary plaque formation with high-fat diet. After performing myocardial FFR by intravascular ultrasound, different doses of CX37 viral suspension, saline and mock small interfering RNA (siRNA) were transfected into the related coronary. The FFR, the myocardial enzymes and the cardiac structures and functions of the pigs were detected at baseline, 4th, 8th and 12th week after transfection, respectively. RESULTS Repeated measures analysis of variance comparison showed that the difference in the FFR among the 5 groups was statistically significant (F = 27.0, P < 0.01). Post hoc analysis showed that FFR were highest in the siRNA CX37 group (20 µl), followed by the siRNA CX37 group (10 µl) and the siRNA CX37 group (5 µl), and lowest in the mock and saline groups. Left ventricular end-diastolic diameter was significantly smaller and ejection fraction was obviously higher in the 3 siRNA CX37 groups compared with the untreated groups. CONCLUSIONS Our study showed that FFR levels increased along with decreased doses of siRNA CX37 lentivirus, indicating that siRNA CX37 lentivirus may reduce the risk of coronary atherosclerosis and provide a potential approach to treat coronary heart disease.
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Affiliation(s)
- Suxia Guo
- Department of Cardiology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Ying Yang
- Department of Cardiology, Affiliated People's Hospital of Nanjing Medical University in Wuxi and People's Hospital of Wuxi City, Wuxi, Jiangsu, China
| | - Zhenyu Yang
- Department of Cardiology, Affiliated People's Hospital of Nanjing Medical University in Wuxi and People's Hospital of Wuxi City, Wuxi, Jiangsu, China
| | - Huayan You
- Department of Cardiology, Affiliated People's Hospital of Nanjing Medical University in Wuxi and People's Hospital of Wuxi City, Wuxi, Jiangsu, China
| | - Yunke Shi
- Department of Cardiology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Zhao Hu
- Department of Cardiology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Zhaohui Meng
- Department of Cardiology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
| | - Jianming Xiao
- Department of Cardiology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan, China
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King MT, Jenkins CH, Sun C, Carpenter CM, Ma X, Cheng K, Le QT, Sunwoo JB, Cheng Z, Pratx G, Xing L. Flexible radioluminescence imaging for FDG-guided surgery. Med Phys 2017; 43:5298. [PMID: 27782732 DOI: 10.1118/1.4961745] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
PURPOSE Flexible radioluminescence imaging (Flex-RLI) is an optical method for imaging 18F-fluorodeoxyglucose (FDG)-avid tumors. The authors hypothesize that a gadolinium oxysulfide: terbium (GOS:Tb) flexible scintillator, which loosely conforms to the body contour, can enhance tumor signal-to-background ratio (SBR) compared with RLI, which utilizes a flat scintillator. The purpose of this paper is to characterize flex-RLI with respect to alternative modalities including RLI, beta-RLI (RLI with gamma rejection), and Cerenkov luminescence imaging (CLI). METHODS The photon sensitivity, spatial resolution, and signal linearity of flex-RLI were characterized with in vitro phantoms. In vivo experiments utilizing 13 nude mice inoculated with the head and neck (UMSCC1-Luc) cell line were then conducted in accordance with the institutional Administrative Panel on Laboratory Animal Care. After intravenous injection of 18F-FDG, the tumor SBR values for flex-RLI were compared to those for RLI, beta-RLI, and CLI using the Wilcoxon signed rank test. RESULTS With respect to photon sensitivity, RLI, beta-RLI, and flex-RLI produced 1216.2, 407.0, and 98.6 times more radiance per second than CLI. Respective full-width half maximum values across a 0.5 mm capillary tube were 6.9, 6.4, 2.2, and 1.5 mm, respectively. Flex-RLI demonstrated a near perfect correlation with 18F activity (r = 0.99). Signal uniformity for flex-RLI improved after more aggressive homogenization of the GOS powder with the silicone elastomer during formulation. In vivo, the SBR value for flex-RLI (median 1.29; interquartile range 1.18-1.36) was statistically greater than that for RLI (1.08; 1.02-1.14; p < 0.01) by 26%. However, there was no statistically significant difference in SBR values between flex-RLI and beta-RLI (p = 0.92). Furthermore, there was no statistically significant difference in SBR values between flex-RLI and CLI (p = 0.11) in a more limited dataset. CONCLUSIONS Flex-RLI provides high quality images with SBRs comparable to those from CLI and beta-RLI in a single 10 s acquisition.
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Affiliation(s)
- Martin T King
- Department of Radiation Oncology, Stanford University, Stanford, California 94305
| | - Cesare H Jenkins
- Department of Radiation Oncology, Stanford University, Stanford, California 94305
| | - Conroy Sun
- College of Pharmacy, Oregon State University, Corvallis, Oregon 97331
| | | | - Xiaowei Ma
- Department of Radiology, Stanford University, Stanford, California 94305 and Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Kai Cheng
- Department of Radiation Oncology, Stanford University, Stanford, California 94305
| | - Quynh-Thu Le
- Department of Radiation Oncology, Stanford University, Stanford, California 94305
| | - John B Sunwoo
- Department of Otolaryngology, Stanford University, Stanford, California 94305
| | - Zhen Cheng
- Department of Radiology, Stanford University, Stanford, California 94305
| | - Guillem Pratx
- Department of Radiation Oncology, Stanford University, Stanford, California 94305
| | - Lei Xing
- Department of Radiation Oncology, Stanford University, Stanford, California 94305
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Imaging inflammation and neovascularization in atherosclerosis: clinical and translational molecular and structural imaging targets. Curr Opin Cardiol 2016; 30:671-80. [PMID: 26398413 DOI: 10.1097/hco.0000000000000226] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
PURPOSE OF REVIEW The purpose of this study is to showcase advances in molecular imaging of atheroma biology in living individuals. RECENT FINDINGS F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) continues to be the predominant molecular imaging approach for clinical applications, particularly in the large arterial beds. Recently, there has been significant progress in imaging of neovascularization and inflammation to delineate high-risk atheroma and to evaluate drug efficacy. In addition, new hardware detection technology and imaging agents are enabling in-vivo imaging of new targets on diverse imaging platforms. SUMMARY In this review, we present recent exciting developments in molecular and structural imaging of atherosclerotic plaque inflammation and neovascularization. Building upon prior studies, these advances develop key technology that will play an important role in propelling new diagnostic and therapeutic strategies identifying high-risk plaque phenotypes and assessing new plaque stabilization therapies in clinical trials.
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Adamson PD, Dweck MR, Newby DE. The vulnerable atherosclerotic plaque: in vivo identification and potential therapeutic avenues. Heart 2015; 101:1755-66. [DOI: 10.1136/heartjnl-2014-307099] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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King MT, Carpenter CM, Sun C, Ma X, Le QT, Sunwoo JB, Cheng Z, Pratx G, Xing L. β-Radioluminescence Imaging: A Comparative Evaluation with Cerenkov Luminescence Imaging. J Nucl Med 2015. [PMID: 26205301 DOI: 10.2967/jnumed.115.158337] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
UNLABELLED Cerenkov luminescence imaging (CLI) can provide high-resolution images of (18)F-FDG-avid tumors but requires prolonged acquisition times because of low photon sensitivity. In this study, we proposed a new modality, termed β-radioluminescence imaging (β-RLI), which incorporates a scintillator with a γ-rejection strategy for imaging β particles. We performed a comparative evaluation of β-RLI with CLI in both in vitro and in vivo systems. METHODS Using in vitro phantoms, we characterized the photon sensitivity and resolution of CLI and β-RLI. We also conducted a series of in vivo experiments with xenograft mouse models using both amelanotic (A375, UMSCC1-Luc) and melanotic (B16F10-Luc) cell lines. The B16F10 and UMSCC1 cell lines were transfected with the luciferase gene (Luc). CLI was acquired over 300 s, and β-RLI was acquired using two 10-s acquisitions. We correlated (18)F -: FDG activities, as assessed by PET, with tumor radiances for both β-RLI and CLI. We also compared tumor signal-to-background ratios (SBRs) between these modalities for amelanotic and melanotic tumors. RESULTS For in vitro experiments, the photon sensitivity for β-RLI was 560-fold greater than that for CLI. However, the spatial resolution for β-RLI (4.4 mm) was inferior to that of CLI (1.0 mm). For in vivo experiments, correlations between (18)F-FDG activity and tumor radiance were 0.52 (P < 0.01) for β-RLI, 0.81 (P = 0.01) for amelanotic lesions with CLI, and -0.08 (negative contrast; P = 0.80) for melanotic lesions with CLI. Nine of 13 melanotic lesions had an SBR less than 1 for CLI, despite an SBR greater than 1 among all lesions for β-RLI. CONCLUSION β-RLI can produce functional images of both amelanotic and melanotic tumors in a shorter time frame than CLI. Further engineering developments are needed to realize the full clinical potential of this modality.
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Affiliation(s)
- Martin T King
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Colin M Carpenter
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Conroy Sun
- College of Pharmacy, Oregon State University, Portland, Oregon
| | - Xiaowei Ma
- Department of Radiology, Stanford University, Stanford, California Department of Nuclear Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China; and
| | - Quynh-Thu Le
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - John B Sunwoo
- Department of Otolaryngology, Stanford University, Stanford, California
| | - Zhen Cheng
- Department of Radiology, Stanford University, Stanford, California
| | - Guillem Pratx
- Department of Radiation Oncology, Stanford University, Stanford, California
| | - Lei Xing
- Department of Radiation Oncology, Stanford University, Stanford, California
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Zaman RT, Kosuge H, Carpenter C, Sun C, McConnell MV, Xing L. Scintillating balloon-enabled fiber-optic system for radionuclide imaging of atherosclerotic plaques. J Nucl Med 2015; 56:771-7. [PMID: 25858046 DOI: 10.2967/jnumed.114.153239] [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: 12/16/2014] [Accepted: 03/18/2015] [Indexed: 01/28/2023] Open
Abstract
UNLABELLED Atherosclerosis underlies coronary artery disease, the leading cause of death in the United States and worldwide. Detection of coronary plaque inflammation remains challenging. In this study, we developed a scintillating balloon-enabled fiber-optic radionuclide imaging (SBRI) system to improve the sensitivity and resolution of plaque imaging using (18)F-FDG, a marker of vascular inflammation, and tested it in a murine model. METHODS The fiber-optic system uses a Complementary Metal-Oxide Silicon (CMOS) camera with a distal ferrule terminated with a wide-angle lens. The novelty of this system is a scintillating balloon in the front of the wide-angle lens to image light from the decay of (18)F-FDG emission signal. To identify the optimal scintillating materials with respect to resolution, we calculated the modulation transfer function of yttrium-aluminum-garnet doped with cerium, anthracene, and calcium fluoride doped with europium (CaF2:Eu) phosphors using an edge pattern and a thin-line optical phantom. The scintillating balloon was then fabricated from 10 mL of silicone RTV catalyst mixed with 1 mL of base and 50 mg of CaF2:Eu per mL. The addition of a lutetium oxyorthosilicate scintillating crystal (500 μm thick) to the balloon was also investigated. The SBRI system was tested in a murine atherosclerosis model: carotid-ligated mice (n = 5) were injected with (18)F-FDG, followed by ex vivo imaging of the macrophage-rich carotid plaques and nonligated controls. Confirmatory imaging of carotid plaques and controls was also performed by an external optical imaging system and autoradiography. RESULTS Analyses of the different phosphors showed that CaF2:Eu enabled the best resolution of 1.2 μm. The SBRI system detected almost a 4-fold-higher radioluminescence signal from the ligated left carotid artery than the nonligated right carotid: 1.63 × 10(2) ± 4.01 × 10(1) vs. 4.21 × 10(1) ± 2.09 × 10(0) (photon counts), P = 0.006. We found no significant benefit to adding a scintillating crystal to the balloon: 1.65 × 10(2) ± 4.07 × 10(1) vs. 4.44 × 10(1) ± 2.17 × 10(0) (photon counts), P = 0.005. Both external optical imaging and autoradiography confirmed the high signal from the (18)F-FDG in carotid plaques versus controls. CONCLUSION This SBRI system provides high-resolution and sensitive detection of (18)F-FDG uptake by murine atherosclerotic plaques.
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Affiliation(s)
- Raiyan T Zaman
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California Division of Radiation Physics, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; and
| | - Hisanori Kosuge
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | | | - Conroy Sun
- Division of Radiation Physics, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; and
| | - Michael V McConnell
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, California
| | - Lei Xing
- Division of Radiation Physics, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; and
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