1
|
Van Camp N, Lavisse S, Roost P, Gubinelli F, Hillmer A, Boutin H. TSPO imaging in animal models of brain diseases. Eur J Nucl Med Mol Imaging 2021; 49:77-109. [PMID: 34245328 PMCID: PMC8712305 DOI: 10.1007/s00259-021-05379-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/25/2021] [Indexed: 12/19/2022]
Abstract
Over the last 30 years, the 18-kDa TSPO protein has been considered as the PET imaging biomarker of reference to measure increased neuroinflammation. Generally assumed to image activated microglia, TSPO has also been detected in endothelial cells and activated astrocytes. Here, we provide an exhaustive overview of the recent literature on the TSPO-PET imaging (i) in the search and development of new TSPO tracers and (ii) in the understanding of acute and chronic neuroinflammation in animal models of neurological disorders. Generally, studies testing new TSPO radiotracers against the prototypic [11C]-R-PK11195 or more recent competitors use models of acute focal neuroinflammation (e.g. stroke or lipopolysaccharide injection). These studies have led to the development of over 60 new tracers during the last 15 years. These studies highlighted that interpretation of TSPO-PET is easier in acute models of focal lesions, whereas in chronic models with lower or diffuse microglial activation, such as models of Alzheimer's disease or Parkinson's disease, TSPO quantification for detection of neuroinflammation is more challenging, mirroring what is observed in clinic. Moreover, technical limitations of preclinical scanners provide a drawback when studying modest neuroinflammation in small brains (e.g. in mice). Overall, this review underlines the value of TSPO imaging to study the time course or response to treatment of neuroinflammation in acute or chronic models of diseases. As such, TSPO remains the gold standard biomarker reference for neuroinflammation, waiting for new radioligands for other, more specific targets for neuroinflammatory processes and/or immune cells to emerge.
Collapse
Affiliation(s)
- Nadja Van Camp
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Sonia Lavisse
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Pauline Roost
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Francesco Gubinelli
- Université Paris-Saclay, CEA, CNRS, MIRCen, Laboratoire des Maladies Neurodégénératives, 92265, Fontenay-aux-Roses, France
| | - Ansel Hillmer
- Department of Psychiatry, Yale School of Medicine, New Haven, CT, USA
- Department of Radiology & Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
- Department of Biomedical Engineering, Yale School of Engineering & Applied Science, New Haven, CT, USA
| | - Hervé Boutin
- Division of Neuroscience and Experimental Psychology, School of Biological Sciences, Faculty of Brain and Mental Health, University of Manchester, M13 9PL, Manchester, UK.
- Wolfson Molecular Imaging Centre, University of Manchester, 27 Palatine Road, M20 3LJ, Manchester, UK.
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre, Northern Care Alliance & University of Manchester, Manchester, UK.
| |
Collapse
|
2
|
Nomura M, Toyama H, Suzuki H, Yamada T, Hatano K, Wilson AA, Ito K, Sawada M. Peripheral benzodiazepine receptor/18 kDa translocator protein positron emission tomography imaging in a rat model of acute brain injury. Ann Nucl Med 2021; 35:8-16. [PMID: 32989663 DOI: 10.1007/s12149-020-01530-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 09/16/2020] [Indexed: 01/28/2023]
Abstract
OBJECTIVE The activation of microglia in various brain pathologies is accompanied by an increase in the expression of peripheral benzodiazepine receptor/18 kDa translocator protein (PBR/TSPO). However, whether activated microglia have a neuroprotective or neurotoxic effect on neurons in the brain is yet to be determined. In this study, we investigated the ability of the novel PBR/TSPO ligand FEPPA to detect activated microglia in an animal model of primary neurotoxic microglia activation. METHODS [18F] FEPPA positron emission tomography (PET) imaging was performed before and after intraperitoneal administration of lipopolysaccharide (LPS) (LPS group) or saline (control group) in a unilateral 6-hydroxydopamine (6-OHDA) lesion rat model of Parkinson's disease. Images were compared between these groups. After imaging, the brains were collected, and the activated microglia at the disease sites were analyzed by the expression of inflammatory cytokines and immunohistochemistry staining. These results were then comparatively examined with those obtained by PET imaging. RESULTS In the unilateral 6-OHDA lesion rat model, the PBR/TSPO PET signal was significantly increased in the LPS group compared with the saline group. As the increased signal was observed 4 h after the injection, we considered it an acute response to brain injury. In the post-imaging pathological examination, activated microglia were found to be abundant at the site where strong signals were detected, and the expression of the inflammatory cytokines TNF-α and IL-1β was increased. Intraperitoneal LPS administration further increased the expression of inflammatory cytokines, and the PBR/TSPO PET signal increased concurrently. The increase in inflammatory cytokine expression correlated with enhanced signal intensity. CONCLUSIONS PET signal enhancement by PBR/TSPO at the site of brain injury correlated with the activation of microglia and production of inflammatory cytokines. Furthermore, because FEPPA enables the detection of neurotoxic microglia on PET images, we successfully constructed a novel PET detection system that can monitor neurodegenerative diseases.
Collapse
Affiliation(s)
- Masahiko Nomura
- Department of Radiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan.
| | - Hiroshi Toyama
- Department of Radiology, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi, 470-1192, Japan
| | - Hiromi Suzuki
- Department of Brain Function, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| | - Takashi Yamada
- Department of Management Nutrition, Faculty of Human Life Science, Nagoya University of Economics, 6-11 Uchikubo, Inuyama, Aichi, Japan
| | - Kentaro Hatano
- Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Alan A Wilson
- PET Centre, Centre for Addiction and Mental Health, Toronto, ON, M5T 1R8, Canada
| | - Kengo Ito
- Department of Clinical and Experimental Neuroimaging, National Center for Geriatrics and Gerontology, 7-430 Morioka-cho, Obu, Aichi, 474-8511, Japan
- Department of Radiology, National Center for Geriatrics and Gerontology, 7-430 Morioka-cho, Obu, Aichi, 474-8511, Japan
| | - Makoto Sawada
- Department of Brain Function, Research Institute of Environmental Medicine, Nagoya University, Nagoya, Japan
| |
Collapse
|
3
|
Dimitrova-Shumkovska J, Krstanoski L, Veenman L. Diagnostic and Therapeutic Potential of TSPO Studies Regarding Neurodegenerative Diseases, Psychiatric Disorders, Alcohol Use Disorders, Traumatic Brain Injury, and Stroke: An Update. Cells 2020; 9:cells9040870. [PMID: 32252470 PMCID: PMC7226777 DOI: 10.3390/cells9040870] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/29/2020] [Accepted: 03/30/2020] [Indexed: 02/08/2023] Open
Abstract
Neuroinflammation and cell death are among the common symptoms of many central nervous system diseases and injuries. Neuroinflammation and programmed cell death of the various cell types in the brain appear to be part of these disorders, and characteristic for each cell type, including neurons and glia cells. Concerning the effects of 18-kDa translocator protein (TSPO) on glial activation, as well as being associated with neuronal cell death, as a response mechanism to oxidative stress, the changes of its expression assayed with the aid of TSPO-specific positron emission tomography (PET) tracers' uptake could also offer evidence for following the pathogenesis of these disorders. This could potentially increase the number of diagnostic tests to accurately establish the stadium and development of the disease in question. Nonetheless, the differences in results regarding TSPO PET signals of first and second generations of tracers measured in patients with neurological disorders versus healthy controls indicate that we still have to understand more regarding TSPO characteristics. Expanding on investigations regarding the neuroprotective and healing effects of TSPO ligands could also contribute to a better understanding of the therapeutic potential of TSPO activity for brain damage due to brain injury and disease. Studies so far have directed attention to the effects on neurons and glia, and processes, such as death, inflammation, and regeneration. It is definitely worthwhile to drive such studies forward. From recent research it also appears that TSPO ligands, such as PK11195, Etifoxine, Emapunil, and 2-Cl-MGV-1, demonstrate the potential of targeting TSPO for treatments of brain diseases and disorders.
Collapse
Affiliation(s)
- Jasmina Dimitrova-Shumkovska
- Department of Experimental Biochemistry, Institute of Biology, Faculty of Natural Sciences and Mathematics, University Ss Cyril and Methodius, Arhimedova 3, P.O. Box 162, 1000 Skopje, Republic of North Macedonia;
- Correspondence: (J.D.-S.); (L.V.)
| | - Ljupcho Krstanoski
- Department of Experimental Biochemistry, Institute of Biology, Faculty of Natural Sciences and Mathematics, University Ss Cyril and Methodius, Arhimedova 3, P.O. Box 162, 1000 Skopje, Republic of North Macedonia;
| | - Leo Veenman
- Technion-Israel Institute of Technology, Faculty of Medicine, Rappaport Institute of Medical Research, 1 Efron Street, P.O. Box 9697, Haifa 31096, Israel
- Correspondence: (J.D.-S.); (L.V.)
| |
Collapse
|
4
|
Zhang X, Yin Q, Berridge M, Wang C. Application of molecular imaging technology in neurotoxicology research. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2018; 36:113-124. [PMID: 30199343 DOI: 10.1080/10590501.2018.1492200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Molecular imaging has been widely applied in preclinical research. Among these new molecular imaging modalities, microPET imaging can be utilized as a very powerful tool that can obtain the measurements of multiple biological processes in various organs repeatedly in a same subject. This review discusses how this new approach provides noninvasive biomarker for neurotoxicology research and summarizes microPET findings with multiple radiotracers on the variety of neurotoxicity induced by toxic agents in both the rodent and the nonhuman primate brain.
Collapse
Affiliation(s)
- Xuan Zhang
- a Division of Neurotoxicology , U.S. Food and Drug Administration, National Center for Toxicological Research , Jefferson , Arkansas , USA
| | - Qi Yin
- a Division of Neurotoxicology , U.S. Food and Drug Administration, National Center for Toxicological Research , Jefferson , Arkansas , USA
| | - Marc Berridge
- b 3D Imaging, LLC, University of Arkansas for Medical Sciences , Little Rock , Arkansas , USA
| | - Che Wang
- a Division of Neurotoxicology , U.S. Food and Drug Administration, National Center for Toxicological Research , Jefferson , Arkansas , USA
| |
Collapse
|
5
|
Zhang X, Liu F, Slikker W, Wang C, Paule MG. Minimally invasive biomarkers of general anesthetic-induced developmental neurotoxicity. Neurotoxicol Teratol 2016; 60:95-101. [PMID: 27784630 DOI: 10.1016/j.ntt.2016.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/29/2016] [Accepted: 10/21/2016] [Indexed: 12/22/2022]
Abstract
The association of general anesthesia with developmental neurotoxicity, while nearly impossible to study in pediatric populations, is clearly demonstrable in a variety of animal models from rodents to nonhuman primates. Nearly all general anesthetics tested have been shown to cause abnormal brain cell death in animals when administered during periods of rapid brain growth. The ability to repeatedly assess in the same subjects adverse effects induced by general anesthetics provides significant power to address the time course of important events associated with exposures. Minimally-invasive procedures provide the opportunity to bridge the preclinical/clinical gap by providing the means to more easily translate findings from the animal laboratory to the human clinic. Positron Emission Tomography or PET is a tool with great promise for realizing this goal. PET for small animals (microPET) is providing valuable data on the life cycle of general anesthetic induced neurotoxicity. PET radioligands (annexin V and DFNSH) targeting apoptotic processes have demonstrated that a single bout of general anesthesia effected during a vulnerable period of CNS development can result in prolonged apoptotic signals lasting for several weeks in the rat. A marker of cellular proliferation (FLT) has demonstrated in rodents that general anesthesia-induced inhibition of neural progenitor cell proliferation is evident when assessed a full 2weeks after exposure. Activated glia express Translocator Protein (TSPO) which can be used as a marker of presumed neuroinflammatory processes and a PET ligand for the TSPO (FEPPA) has been used to track this process in both rat and nonhuman primate models. It has been shown that single bouts of general anesthesia can result in elevated TSPO expression lasting for over a week. These examples demonstrate the utility of specific PET tracers to inform, in a minimally-invasive fashion, processes associated with general anesthesia-induced developmental neurotoxicity. The fact that PET procedures are also used clinically suggests an opportunity to confirm in humans what has been repeatedly observed in animals.
Collapse
|
6
|
In Vivo Monitoring of Sevoflurane-induced Adverse Effects in Neonatal Nonhuman Primates Using Small-animal Positron Emission Tomography. Anesthesiology 2016; 125:133-46. [DOI: 10.1097/aln.0000000000001154] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Abstract
Background
Animals exposed to sevoflurane during development sustain neuronal cell death in their developing brains. In vivo micro-positron emission tomography (PET)/computed tomography imaging has been utilized as a minimally invasive method to detect anesthetic-induced neuronal adverse effects in animal studies.
Methods
Neonatal rhesus monkeys (postnatal day 5 or 6, 3 to 6 per group) were exposed for 8 h to 2.5% sevoflurane with or without acetyl-l-carnitine (ALC). Control monkeys were exposed to room air with or without ALC. Physiologic status was monitored throughout exposures. Depth of anesthesia was monitored using quantitative electroencephalography. After the exposure, microPET/computed tomography scans using 18F-labeled fluoroethoxybenzyl-N-(4-phenoxypyridin-3-yl) acetamide (FEPPA) were performed repeatedly on day 1, 1 and 3 weeks, and 2 and 6 months after exposure.
Results
Critical physiologic metrics in neonatal monkeys remained within the normal range during anesthetic exposures. The uptake of [18F]-FEPPA in the frontal and temporal lobes was increased significantly 1 day or 1 week after exposure, respectively. Analyses of microPET images recorded 1 day after exposure showed that sevoflurane exposure increased [18F]-FEPPA uptake in the frontal lobe from 0.927 ± 0.04 to 1.146 ± 0.04, and in the temporal lobe from 0.859 ± 0.05 to 1.046 ± 0.04 (mean ± SE, P < 0.05). Coadministration of ALC effectively blocked the increase in FEPPA uptake. Sevoflurane-induced adverse effects were confirmed by histopathologic evidence as well.
Conclusions
Sevoflurane-induced general anesthesia during development increases glial activation, which may serve as a surrogate for neurotoxicity in the nonhuman primate brain. ALC is a potential protective agent against some of the adverse effects associated with such exposures.
Collapse
|
7
|
Jawaid A, Krajewska J, Pawliczak F, Kandra V, Schulz PE. A Macro Role for Microglia in Poststroke Depression. J Am Geriatr Soc 2016; 64:459-61. [DOI: 10.1111/jgs.13974] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ali Jawaid
- Brain Research Institute; Swiss Federal Institute of Technology; University of Zurich; Zurich Switzerland
| | | | | | | | - Paul E. Schulz
- Department of Neurology; University of Texas Health Science Center at Houston; Houston Texas
| |
Collapse
|
8
|
Walker MD, Dinelle K, Kornelsen R, Lee NV, Miao Q, Adam M, Takhar C, Mak E, Schulzer M, Farrer MJ, Sossi V. [11C]PBR28 PET imaging is sensitive to neuroinflammation in the aged rat. J Cereb Blood Flow Metab 2015; 35:1331-8. [PMID: 25833342 PMCID: PMC4528008 DOI: 10.1038/jcbfm.2015.54] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Revised: 01/28/2015] [Accepted: 03/09/2015] [Indexed: 11/09/2022]
Abstract
Neuroinflammation in the aging rat brain was investigated using [(11)C]PBR28 microPET (positron emission tomography) imaging. Normal rats were studied alongside LRRK2 p.G2019S transgenic rats; this mutation increases the risk of Parkinson's disease in humans. Seventy [(11)C]PBR28 PET scans were acquired. Arterial blood sampling enabled tracer kinetic modeling and estimation of VT. In vitro autoradiography was also performed. PBR28 uptake increased with age, without differences between nontransgenic and transgenic rats. In 12 months of aging (4 to 16 months), standard uptake value (SUV) increased by 56% from 0.44 to 0.69 g/mL, whereas VT increased by 91% from 30 to 57 mL/cm(3). Standard uptake value and VT were strongly correlated (r = 0.52, 95% confidence interval (CI) = 0.31 to 0.69, n = 37). The plasma free fraction, fp, was 0.21 ± 0.03 (mean ± standard deviation, n = 53). In vitro binding increased by 19% in 16 months of aging (4 to 20 months). The SUV was less variable across rats than VT; coefficients of variation were 13% (n = 27) and 29% (n = 12). The intraclass correlation coefficient for SUV was 0.53, but was effectively zero for VT. These data show that [(11)C]PBR28 brain uptake increases with age, implying increased microglial activation in the aged brain.
Collapse
Affiliation(s)
- Matthew D Walker
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| | - Katherine Dinelle
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Rick Kornelsen
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nathan V Lee
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Qing Miao
- TRIUMF, Vancouver, British Columbia, Canada
| | - Mike Adam
- TRIUMF, Vancouver, British Columbia, Canada
| | | | - Edwin Mak
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael Schulzer
- Pacific Parkinson's Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Matthew J Farrer
- Department of Medical Genetics, Centre for Applied Neurogenetics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Vesna Sossi
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
9
|
Hatano K, Sekimata K, Yamada T, Abe J, Ito K, Ogawa M, Magata Y, Toyohara J, Ishiwata K, Biggio G, Serra M, Laquintana V, Denora N, Latrofa A, Trapani G, Liso G, Suzuki H, Sawada M, Nomura M, Toyama H. Radiosynthesis and in vivo evaluation of two imidazopyridineacetamides, [(11)C]CB184 and [ (11)C]CB190, as a PET tracer for 18 kDa translocator protein: direct comparison with [ (11)C](R)-PK11195. Ann Nucl Med 2015; 29:325-35. [PMID: 25616581 PMCID: PMC4835529 DOI: 10.1007/s12149-015-0948-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 01/14/2015] [Indexed: 10/31/2022]
Abstract
OBJECTIVE We report synthesis of two carbon-11 labeled imidazopyridines TSPO ligands, [(11)C]CB184 and [(11)C]CB190, for PET imaging of inflammatory process along with neurodegeneration, ischemia or brain tumor. Biodistribution of these compounds was compared with that of [(11)C]CB148 and [(11)C](R)-PK11195. METHODS Both [(11)C]CB184 and [(11)C]CB190 having (11)C-methoxyl group on an aromatic ring were readily prepared using [(11)C]methyl triflate. Biodistribution and metabolism of the compounds were examined with normal mice. An animal PET study using 6-hydroxydopamine treated rats as a model of neurodegeneration was pursued for proper estimation of feasibility of the radioligands to determine neuroinflammation process. RESULTS [(11)C]CB184 and [(11)C]CB190 were obtained via O-methylation of corresponding desmethyl precursor using [(11)C]methyl triflate in radiochemical yield of 73 % (decay-corrected). In vivo validation as a TSPO radioligand was carried out using normal mice and lesioned rats. In mice, [(11)C]CB184 showed more uptake and specific binding than [(11)C]CB190. Metabolism studies showed that 36 % and 25 % of radioactivity in plasma remained unchanged 30 min after intravenous injection of [(11)C]CB184 and [(11)C]CB190, respectively. In the PET study using rats, lesioned side of the brain showed significantly higher uptake than contralateral side after i.v. injection of either [(11)C]CB184 or [(11)C](R)-PK11195. Indirect Logan plot analysis revealed distribution volume ratio (DVR) between the two sides which might indicate lesion-related elevation of TSPO binding. The DVR was 1.15 ± 0.10 for [(11)C](R)-PK11195 and was 1.15 ± 0.09 for [(11)C]CB184. CONCLUSION The sensitivity to detect neuroinflammation activity was similar for [(11)C]CB184 and [(11)C](R)-PK11195.
Collapse
Affiliation(s)
- Kentaro Hatano
- Department of Clinical and Experimental Neuroimaging, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, 474-8522, Japan,
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Zhang X, Paule MG, Wang C, Slikker W. Application of microPET imaging approaches in the study of pediatric anesthetic-induced neuronal toxicity. J Appl Toxicol 2013; 33:861-8. [DOI: 10.1002/jat.2857] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 12/13/2012] [Accepted: 12/14/2012] [Indexed: 12/14/2022]
Affiliation(s)
- Xuan Zhang
- Division of Neurotoxicology; National Center for Toxicological Research (NCTR)/FDA; Jefferson; AR; USA
| | - Merle G. Paule
- Division of Neurotoxicology; National Center for Toxicological Research (NCTR)/FDA; Jefferson; AR; USA
| | - Cheng Wang
- Division of Neurotoxicology; National Center for Toxicological Research (NCTR)/FDA; Jefferson; AR; USA
| | - William Slikker
- Office of the Director; National Center for Toxicological Research (NCTR)/FDA; Jefferson; AR; USA
| |
Collapse
|
11
|
Mattner F, Staykova M, Berghofer P, Wong HJ, Fordham S, Callaghan P, Jackson T, Pham T, Gregoire MC, Zahra D, Rahardjo G, Linares D, Katsifis A. Central nervous system expression and PET imaging of the translocator protein in relapsing-remitting experimental autoimmune encephalomyelitis. J Nucl Med 2013; 54:291-8. [PMID: 23321458 DOI: 10.2967/jnumed.112.108894] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED Glial neuroinflammation is associated with the development and progression of multiple sclerosis. PET imaging offers a unique opportunity to evaluate neuroinflammatory processes longitudinally in a noninvasive and clinically translational manner. (18)F-PBR111 is a newly developed PET radiopharmaceutical with high affinity and selectivity for the translocator protein (TSPO), expressed on activated glia. This study aimed to investigate neuroinflammation at different phases of relapsing-remitting (RR) experimental autoimmune encephalomyelitis (EAE) in the brains of SJL/J mice by postmortem histologic analysis and in vivo by PET imaging with (18)F-PBR111. METHODS RR EAE was induced by immunization with PLP(139-151) peptide in complete Freund's adjuvant. Naive female SJL/J mice and mice immunized with saline-complete Freund's adjuvant were used as controls. The biodistribution of (18)F-PBR111 was measured in 13 areas of the central nervous system and compared with PET imaging results during different phases of RR EAE. The extents of TSPO expression and glial activation were assessed with immunohistochemistry, immunofluorescence, and a real-time polymerase chain reaction. RESULTS There was significant TSPO expression in all of the central nervous system areas studied at the peak of the first clinical episode and, importantly, at the preclinical stage. In contrast, only a few TSPO-positive cells were observed at the second episode. At the third episode, there was again an increase in TSPO expression. TSPO expression was associated with microglial cells or macrophages without obvious astrocyte labeling. The dynamics of (18)F-PBR111 uptake in the brain, as measured by in vivo PET imaging and biodistribution, followed the pattern of TSPO expression during RR EAE. CONCLUSION PET imaging with the TSPO ligand (18)F-PBR111 clearly reflected the dynamics of microglial activation in the SJL/J mouse model of RR EAE. The results are the first to highlight the discrepancy between the clinical symptoms of EAE and TSPO expression in the brain, as measured by PET imaging at the peaks of various EAE episodes. The results suggest a significant role for PET imaging investigations of neuroinflammation in multiple sclerosis and allow for in vivo follow-up of antiinflammatory treatment strategies.
Collapse
Affiliation(s)
- Filomena Mattner
- Life Sciences Division, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales, Australia.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Zhang X, Paule MG, Newport GD, Liu F, Callicott R, Liu S, Berridge MS, Apana SM, Slikker W, Wang C. MicroPET/CT Imaging of [18F]-FEPPA in the Nonhuman Primate: A Potential Biomarker of Pathogenic Processes Associated with Anesthetic-Induced Neurotoxicity. ACTA ACUST UNITED AC 2012. [DOI: 10.5402/2012/261640] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Background. The inhalation anesthetics nitrous oxide (N2O) and isoflurane (ISO) are used in surgical procedures for human infants. Injury to the central nervous system is often accompanied by localization of activated microglia or astrocytosis at the site of injury. The tracer that targets to the peripheral benzodiazepine receptor (PBR), [18F]N-2-(2-fluoroethoxy)benzyl)-N-(4-phenoxypyridin-3-yl)acetamide ([18F]-FEPPA), has been reported as a sensitive biomarker for the detection of neuronal damage/inflammation. Methods. On postnatal day (PND) 5 or 6 rhesus monkey neonates were exposed to a mixture of N2O/oxygen and ISO for 8 hours and control monkeys were exposed to room air. MicroPET/CT images with [18F]-FEPPA were obtained for each monkey 1 day, one week, three weeks, and 6 months after the anesthetic exposure. Results. The radiotracer quickly distributed into the brains of both treated and control monkeys on all scan days. One day after anesthetic exposure, the uptake of [18F]-FEPPA was significantly increased in the temporal lobe. One week after exposure, the uptake of [18F]-FEPPA in the frontal lobe of treated animals was significantly greater than that in controls. Conclusions. These findings suggest that microPET imaging is capable of dynamic detection of inhaled anesthetic-induced brain damage in different brain regions of the nonhuman primate.
Collapse
Affiliation(s)
- Xuan Zhang
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA
| | - Merle G. Paule
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA
| | - Glenn D. Newport
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA
| | - Fang Liu
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA
| | - Ralph Callicott
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA
| | - Shuliang Liu
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA
| | - Marc S. Berridge
- 3D Imaging, LLC, Little Rock, AR 72113, USA
- University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Scott M. Apana
- 3D Imaging, LLC, Little Rock, AR 72113, USA
- University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - William Slikker
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA
| | - Cheng Wang
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA
| |
Collapse
|
13
|
Ungersboeck J, Philippe C, Haeusler D, Mitterhauser M, Lanzenberger R, Dudczak R, Wadsak W. Optimization of [11C]DASB-synthesis: vessel-based and flow-through microreactor methods. Appl Radiat Isot 2012; 70:2615-20. [PMID: 22940416 DOI: 10.1016/j.apradiso.2012.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 07/24/2012] [Accepted: 08/02/2012] [Indexed: 11/25/2022]
Abstract
The intention for the present study was to implement a microfluidic set-up for N-(11)C-methylations in a flow-through microreactor device with [(11)C]DASB as model-compound and [(11)C]CH(3)I and [(11)C]CH(3)OTf, respectively, as (11)C-methylation agents. Due to an observed "aging" effect of the (11)C-methylation agents' solution, this goal was not achieved. Nevertheless, based on these observations, the time consumption for the vessel-based routine production of [(11)C]DASB was reduced (34±1 min) and RCY was increased to 45.1±4.6% (EOB; 5.2±0.95 GBq EOS).
Collapse
Affiliation(s)
- Johanna Ungersboeck
- Radiochemistry and Biomarker Development Unit, Department of Nuclear Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | | | | | | | | | | | | |
Collapse
|
14
|
Liu F, Zhang X, A. Patterson T, Liu S, Ali SF, Paule MG, Slikker W, Wang C. Assessment of Potential Neuronal Toxicity of Inhaled Anesthetics in the Developing Nonhuman Primate. ACTA ACUST UNITED AC 2012. [DOI: 10.4303/jdar/235607] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
15
|
|
16
|
Folkersma H, Foster Dingley JC, van Berckel BNM, Rozemuller A, Boellaard R, Huisman MC, Lammertsma AA, Vandertop WP, Molthoff CFM. Increased cerebral (R)-[(11)C]PK11195 uptake and glutamate release in a rat model of traumatic brain injury: a longitudinal pilot study. J Neuroinflammation 2011; 8:67. [PMID: 21672189 PMCID: PMC3132713 DOI: 10.1186/1742-2094-8-67] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Accepted: 06/14/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The aim of the present study was to investigate microglia activation over time following traumatic brain injury (TBI) and to relate these findings to glutamate release. PROCEDURES Sequential dynamic (R)-[(11)C]PK11195 PET scans were performed in rats 24 hours before (baseline), and one and ten days after TBI using controlled cortical impact, or a sham procedure. Extracellular fluid (ECF) glutamate concentrations were measured using cerebral microdialysis. Brains were processed for histopathology and (immuno)-histochemistry. RESULTS Ten days after TBI, (R)-[(11)C]PK11195 binding was significantly increased in TBI rats compared with both baseline values and sham controls (p < 0.05). ECF glutamate values were increased immediately after TBI (27.6 ± 14.0 μmol·L(-1)) as compared with the sham procedure (6.4 ± 3.6 μmol·L(-1)). Significant differences were found between TBI and sham for ED-1, OX-6, GFAP, Perl's, and Fluoro-Jade B. CONCLUSIONS Increased cerebral uptake of (R)-[(11)C]PK11195 ten days after TBI points to prolonged and ongoing activation of microglia. This activation followed a significant acute posttraumatic increase in ECF glutamate levels.
Collapse
Affiliation(s)
- Hedy Folkersma
- Neurosurgical Center Amsterdam, VU University Medical Center, De Boelelaan 1117, NL-1081 HV Amsterdam, The Netherlands.
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Tufekci KU, Genc S, Genc K. The endotoxin-induced neuroinflammation model of Parkinson's disease. PARKINSON'S DISEASE 2011; 2011:487450. [PMID: 21331154 PMCID: PMC3034925 DOI: 10.4061/2011/487450] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Revised: 11/18/2010] [Accepted: 12/16/2010] [Indexed: 01/22/2023]
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the progressive loss of dopaminergic (DA) neurons in the substantia nigra. Although the exact cause of the dopaminergic neurodegeneration remains elusive, recent postmortem and experimental studies have revealed an essential role for neuroinflammation that is initiated and driven by activated microglial and infiltrated peripheral immune cells and their neurotoxic products (such as proinflammatory cytokines, reactive oxygen species, and nitric oxide) in the pathogenesis of PD. A bacterial endotoxin-based experimental model of PD has been established, representing a purely inflammation-driven animal model for the induction of nigrostriatal dopaminergic neurodegeneration. This model, by itself or together with genetic and toxin-based animal models, provides an important tool to delineate the precise mechanisms of neuroinflammation-mediated dopaminergic neuron loss. Here, we review the characteristics of this model and the contribution of neuroinflammatory processes, induced by the in vivo administration of bacterial endotoxin, to neurodegeneration. Furthermore, we summarize the recent experimental therapeutic strategies targeting endotoxin-induced neuroinflammation to elicit neuroprotection in the nigrostriatal dopaminergic system. The potential of the endotoxin-based PD model in the development of an early-stage specific diagnostic biomarker is also emphasized.
Collapse
Affiliation(s)
- Kemal Ugur Tufekci
- Department of Neuroscience, Health Science Institute, Dokuz Eylul University, Inciralti, 35340 Izmir, Turkey
| | - Sermin Genc
- Department of Neuroscience, Health Science Institute, Dokuz Eylul University, Inciralti, 35340 Izmir, Turkey
| | - Kursad Genc
- Department of Neuroscience, Health Science Institute, Dokuz Eylul University, Inciralti, 35340 Izmir, Turkey
| |
Collapse
|
18
|
Ono K, Suzuki H, Sawada M. Delayed neural damage is induced by iNOS-expressing microglia in a brain injury model. Neurosci Lett 2010; 473:146-50. [DOI: 10.1016/j.neulet.2010.02.041] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2010] [Revised: 02/12/2010] [Accepted: 02/13/2010] [Indexed: 11/25/2022]
|