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Chen DL, Agapov E, Wu K, Engle JT, Solingapuram Sai KK, Arentson E, Spayd KJ, Moreland KT, Toth K, Byers DE, Pierce RA, Atkinson JJ, Laforest R, Gelman AE, Holtzman MJ. Selective Imaging of Lung Macrophages Using [ 11C]PBR28-Based Positron Emission Tomography. Mol Imaging Biol 2021; 23:905-913. [PMID: 34137002 DOI: 10.1007/s11307-021-01617-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 01/17/2023]
Abstract
PURPOSE We tested whether the translocator protein (TSPO)-targeted positron emission tomography (PET) tracer, N-acetyl-N-(2-[11C]methoxybenzyl)-2-phenoxy-5-pyridinamine ([11C]PBR28), could distinguish macrophage dominant from neutrophilic inflammation better than 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) in mouse models of lung inflammation and assessed TSPO association with macrophages in lung tissue from the mouse models and in patients with chronic obstructive pulmonary disease (COPD). PROCEDURES MicroPET imaging quantified [11C]PBR28 and [18F]FDG lung uptake in wild-type (Wt) C57BL/6J or heterozygous transgenic monocyte-deficient Wt/opT mice at 49 days after Sendai virus (SeV) infection, during macrophage-dominant inflammation, and in Wt mice at 3 days after SeV infection or 24 h after endotoxin instillation during neutrophilic inflammation. Immunohistochemical staining for TSPO in macrophages and neutrophils was performed using Mac3 and Ly6G for cell identification in mouse lung sections and CD68 and neutrophil elastase (NE) in human lung sections taken from explanted lungs from patients with COPD undergoing lung transplantation and donor lungs rejected for transplantation. Differences in tracer uptake among SeV-infected, endotoxin-treated, and uninfected/untreated control mice and in TSPO staining between neutrophils and macrophage populations in human lung sections were tested using analysis of variance. RESULTS In Wt mice, [11C]PBR28 uptake (% injected dose/ml lung tissue) increased significantly with macrophage-dominant inflammation at 49 days (D49) after SeV infection compared to controls (p = <0.001) but not at 3 days (D49) after SeV infection (p = 0.167). [11C]PBR28 uptake was unchanged at 24 h after endotoxin instillation (p = 0.958). [18F]FDG uptake increased to a similar degree in D3 and D49 SeV-infected and endotoxin-treated Wt mice compared to controls with no significant difference in the degree of increase among the tested conditions. [11C]PBR28 but not [18F]FDG lung uptake at D49 post-SeV infection was attenuated in Wt/opT mice compared to Wt mice. TSPO localized predominantly to macrophages in mouse lung tissue by immunostaining, and TSPO staining intensity was significantly higher in CD68+ cells compared to neutrophils in the human lung sections. CONCLUSIONS PET imaging with [11C]PBR28 can specifically detect macrophages versus neutrophils during lung inflammation and may be a useful biomarker of macrophage accumulation in lung disease.
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Affiliation(s)
- Delphine L Chen
- Division of Radiological Sciences and Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA. .,Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA. .,Department of Radiology, University of Washington, Seattle Cancer Care Alliance, 1144 Eastlake Ave E, # LG2-200, Seattle, WA, 98109, USA.
| | - Eugene Agapov
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Kangyun Wu
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Jacquelyn T Engle
- Division of Radiological Sciences and Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | | | - Elizabeth Arentson
- Division of Radiological Sciences and Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Katherine J Spayd
- Division of Radiological Sciences and Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kirby T Moreland
- Division of Radiological Sciences and Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Kelsey Toth
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - Derek E Byers
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Richard A Pierce
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Jeffrey J Atkinson
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Richard Laforest
- Division of Radiological Sciences and Nuclear Medicine, Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Andrew E Gelman
- Division of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine, St. Louis, MO, USA
| | - Michael J Holtzman
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Washington University School of Medicine, St. Louis, MO, USA
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Wu CY, Chen YY, Lin JJ, Li JP, Chen JK, Hsieh TC, Kao CH. Development of a novel radioligand for imaging 18-kD translocator protein (TSPO) in a rat model of Parkinson's disease. BMC Med Imaging 2019; 19:78. [PMID: 31533645 PMCID: PMC6751751 DOI: 10.1186/s12880-019-0375-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 08/18/2019] [Indexed: 01/24/2023] Open
Abstract
Purpose The inflammation reaction in the brain may stimulate damage repair or possibly lead to secondary brain injury. It is often associated with activated microglia, which would overexpress 18-kDa translocator protein (TSPO). In this study, we successfully developed a new TSPO radioligand, [18F]-2-(4-fluoro-2-(p-tolyloxy)phenyl)-1,2-dihydroisoquinolin-3(4H)-one ([18F]FTPQ), and evaluate its potential to noninvasively detect brain changes in a rat model of Parkinson’s disease (PD). Procedures The precursor (8) for [18F]FTPQ preparation was synthesized via six steps. Radiofluorination was carried out in the presence of a copper catalyst, and the crude product was purified by high-performance liquid chromatography (HPLC) to give the desired [18F]FTPQ. The rat model of PD was established by the injection of 6-OHDA into the right hemisphere of male 8-week-old Sprague-Dawley rats. MicroPET/CT imaging and immunohistochemistry (IHC) were performed to characterize the biological properties of [18F]FTPQ. Results The overall chemical yield for the precursor (8) was around 14% after multi-step synthesis. The radiofluorination efficiency of [18F]FTPQ was 60 ± 5%. After HPLC purification, the radiochemical purity was higher than 98%. The overall radiochemical yield was approximately 19%. The microPET/CT images demonstrated apparent striatum accumulation in the brains of PD rats at the first 30 min after intravenous injection of [18F]FTPQ. Besides, longitudinal imaging found the uptake of [18F]FTPQ in the brain may reflect the severity of PD. The radioactivity accumulated in the ipsilateral hemisphere of PD rats at 1, 2, and 3 weeks after 6-OHDA administration was 1.84 ± 0.26, 3.43 ± 0.45, and 5.58 ± 0.72%ID/mL, respectively. IHC revealed that an accumulation of microglia/macrophages and astrocytes in the 6-OHDA-injected hemisphere. Conclusions In this study, we have successfully synthesized [18F]FTPQ with acceptable radiochemical yield and demonstrated the feasibility of [18F]FTPQ as a TSPO radioligand for the noninvasive monitoring the disease progression of PD. Electronic supplementary material The online version of this article (10.1186/s12880-019-0375-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chun-Yi Wu
- Department of Biomedical Imaging and Radiological Science, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402.,Master Program for Biomedical Engineering, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402
| | - Yang-Yi Chen
- Department of Biomedical Imaging and Radiological Sciences, National Yang-Ming University, No.155, Sec.2, Linong Street, Taipei, Taiwan, 11221
| | - Jia-Jia Lin
- Department of Biomedical Imaging and Radiological Science, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402
| | - Jui-Ping Li
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County, Taiwan, 35053
| | - Jen-Kun Chen
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County, Taiwan, 35053
| | - Te-Chun Hsieh
- Department of Biomedical Imaging and Radiological Science, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402. .,Graduate Institute of Biomedical Sciences and School of Medicine, College of Medicine, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402.
| | - Chia-Hung Kao
- Graduate Institute of Biomedical Sciences and School of Medicine, College of Medicine, China Medical University, No.91, Hsueh-Shih Road, Taichung, Taiwan, 40402. .,Department of Nuclear Medicine and PET Center, and Center of Augmented Intelligence in Healthcare, China Medical University Hospital, No. 2, Yude Road, North District, Taichung City, Taiwan, 40447. .,Department of Bioinformatics and Medical Engineering, Asia University, 500, Lioufeng Rd., Wufeng, Taichung, Taiwan, 41354.
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Guedes CES, Dias BRS, Petersen ALDOA, Cruz KP, Almeida NDJ, Andrade DR, Menezes JPBD, Borges VDM, Veras PST. In vitro evaluation of the anti-leishmanial activity and toxicity of PK11195. Mem Inst Oswaldo Cruz 2018; 113:e170345. [PMID: 29412342 PMCID: PMC5851033 DOI: 10.1590/0074-02760170345] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/30/2017] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Leishmaniasis, one of the most neglected diseases, is a serious public health problem in many countries, including Brazil. Currently available treatments require long-term use and have serious side effects, necessitating the development of new therapeutic interventions. Because translocator protein (TSPO) levels are reduced in Leishmania amazonensis-infected cells and because this protein participates in apoptosis and immunomodulation, TSPO represents a potential target for Leishmania chemotherapy. The present study evaluated PK11195, a ligand of this protein, as an anti-leishmanial agent. OBJECTIVE To evaluate the leishmanicidal activity of PK11195 against L. amazonensis in infected CBA mouse macrophages in vitro. METHODS The viability of axenic L. amazonensis, Leishmania major, and Leishmania braziliensis promastigotes was assessed after 48 h treatment with PK11195 (0.2-400 µM). Additionally, intracellular parasite viability was evaluated to determine IC50 values and the number of viable parasites in infected macrophages treated with PK11195 (50-100 µM). Infected macrophages were then treated with PK11195 (25-100 µM) to determine the percentage of L. amazonensis-infected cells and the number of parasites per infected cell. Electron microscopy was used to investigate morphological changes caused by PK11195. The production of free oxygen radicals, nitric oxide, and pro-inflammatory cytokines was also evaluated in infected macrophages treated with PK11195 and primed or not primed with IFN-γ. FINDINGS Median IC50 values for PK11195 were 14.2 µM for L. amazonensis, 8.2 µM for L. major, and 3.5 µM for L. braziliensis. The selective index value for L. amazonensis was 13.7, indicating the safety of PK11195 for future testing in mammals. Time- and dose-dependent reductions in the percentage of infected macrophages, the number of parasites per infected macrophage, and the number of viable intracellular parasites were observed. Electron microscopy revealed some morphological alterations suggestive of autophagy. Interestingly, MCP-1 and superoxide levels were reduced in L. amazonensis-infected macrophages treated with PK11195. MAIN CONCLUSIONS PK11195 causes the killing of amastigotes in vitro by mechanisms independent of inflammatory mediators and causes morphological alterations within Leishmania parasites, suggestive of autophagy, at doses that are non-toxic to macrophages. Thus, this molecule has demonstrated potential as an anti-leishmanial agent.
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Affiliation(s)
- Carlos Eduardo Sampaio Guedes
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | - Beatriz Rocha Simões Dias
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | | | - Kercia Pinheiro Cruz
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | - Niara de Jesus Almeida
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
| | - Daniela Rodrigues Andrade
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório Integrado de Microbiologia e Imunoregulação, Salvador, BA, Brasil
| | | | - Valéria de Matos Borges
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório Integrado de Microbiologia e Imunoregulação, Salvador, BA, Brasil
| | - Patricia Sampaio Tavares Veras
- Fundação Oswaldo Cruz-Fiocruz, Centro de Pesquisas Gonçalo Moniz, Laboratório de Patologia e Biointervenção, Salvador, BA, Brasil
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Barichello T, Simões LR, Collodel A, Giridharan VV, Dal-Pizzol F, Macedo D, Quevedo J. The translocator protein (18 kDa) and its role in neuropsychiatric disorders. Neurosci Biobehav Rev 2017; 83:183-199. [DOI: 10.1016/j.neubiorev.2017.10.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 09/20/2017] [Accepted: 10/10/2017] [Indexed: 02/08/2023]
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5
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Owen DR, Narayan N, Wells L, Healy L, Smyth E, Rabiner EA, Galloway D, Williams JB, Lehr J, Mandhair H, Peferoen LA, Taylor PC, Amor S, Antel JP, Matthews PM, Moore CS. Pro-inflammatory activation of primary microglia and macrophages increases 18 kDa translocator protein expression in rodents but not humans. J Cereb Blood Flow Metab 2017; 37:2679-2690. [PMID: 28530125 PMCID: PMC5536262 DOI: 10.1177/0271678x17710182] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The 18kDa Translocator Protein (TSPO) is the most commonly used tissue-specific marker of inflammation in positron emission tomography (PET) studies. It is expressed in myeloid cells such as microglia and macrophages, and in rodent myeloid cells expression increases with cellular activation. We assessed the effect of myeloid cell activation on TSPO gene expression in both primary human and rodent microglia and macrophages in vitro, and also measured TSPO radioligand binding with 3H-PBR28 in primary human macrophages. As observed previously, we found that TSPO expression increases (∼9-fold) in rodent-derived macrophages and microglia upon pro-inflammatory stimulation. However, TSPO expression does not increase with classical pro-inflammatory activation in primary human microglia (fold change 0.85 [95% CI 0.58-1.12], p = 0.47). In contrast, pro-inflammatory activation of human monocyte-derived macrophages is associated with a reduction of both TSPO gene expression (fold change 0.60 [95% CI 0.45-0.74], p = 0.02) and TSPO binding site abundance (fold change 0.61 [95% CI 0.49-0.73], p < 0.0001). These findings have important implications for understanding the biology of TSPO in activated macrophages and microglia in humans. They are also clinically relevant for the interpretation of PET studies using TSPO targeting radioligands, as they suggest changes in TSPO expression may reflect microglial and macrophage density rather than activation phenotype.
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Affiliation(s)
- David R Owen
- 1 Division of Brain Sciences, Department of Medicine Hammersmith Hospital, Imperial College London, London, UK
| | - Nehal Narayan
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Lisa Wells
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK
| | - Luke Healy
- 4 Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Erica Smyth
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK
| | - Eugenii A Rabiner
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK.,5 Centre for Neuroimaging Sciences, King's College, London, UK
| | - Dylan Galloway
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - John B Williams
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - Joshua Lehr
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - Harpreet Mandhair
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Laura An Peferoen
- 7 Pathology Department, VU Medical Centre, VU University of Amsterdam, The Netherlands
| | - Peter C Taylor
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Sandra Amor
- 7 Pathology Department, VU Medical Centre, VU University of Amsterdam, The Netherlands.,8 Neuroimmunology Unit, Blizard Institute, Barts and the London School of medicine & Dentistry Queen Mary University of London, UK
| | - Jack P Antel
- 4 Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Paul M Matthews
- 1 Division of Brain Sciences, Department of Medicine Hammersmith Hospital, Imperial College London, London, UK.,9 UK Dementia Research Institute, Imperial College London, London, UK
| | - Craig S Moore
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
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6
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Kim T, Pae AN. Translocator protein (TSPO) ligands for the diagnosis or treatment of neurodegenerative diseases: a patent review (2010 – 2015; part 2). Expert Opin Ther Pat 2016; 26:1353-1366. [DOI: 10.1080/13543776.2016.1230605] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- TaeHun Kim
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology, Seoul, Republic of Korea
- Biological Chemistry, Korea University of Science and Technology, Daejon, Republic of Korea
| | - Ae Nim Pae
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology, Seoul, Republic of Korea
- Biological Chemistry, Korea University of Science and Technology, Daejon, Republic of Korea
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TSPO: kaleidoscopic 18-kDa amid biochemical pharmacology, control and targeting of mitochondria. Biochem J 2016; 473:107-21. [PMID: 26733718 DOI: 10.1042/bj20150899] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The 18-kDa translocator protein (TSPO) localizes in the outer mitochondrial membrane (OMM) of cells and is readily up-regulated under various pathological conditions such as cancer, inflammation, mechanical lesions and neurological diseases. Able to bind with high affinity synthetic and endogenous ligands, its core biochemical function resides in the translocation of cholesterol into the mitochondria influencing the subsequent steps of (neuro-)steroid synthesis and systemic endocrine regulation. Over the years, however, TSPO has also been linked to core cellular processes such as apoptosis and autophagy. It interacts and forms complexes with other mitochondrial proteins such as the voltage-dependent anion channel (VDAC) via which signalling and regulatory transduction of these core cellular events may be influenced. Despite nearly 40 years of study, the precise functional role of TSPO beyond cholesterol trafficking remains elusive even though the recent breakthroughs on its high-resolution crystal structure and contribution to quality-control signalling of mitochondria. All this along with a captivating pharmacological profile provides novel opportunities to investigate and understand the significance of this highly conserved protein as well as contribute the development of specific therapeutics as presented and discussed in the present review.
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Cheung YY, Nickels ML, Tang D, Buck JR, Manning HC. Facile synthesis of SSR180575 and discovery of 7-chloro-N,N,5-trimethyl-4-oxo-3(6-[(18)F]fluoropyridin-2-yl)-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide, a potent pyridazinoindole ligand for PET imaging of TSPO in cancer. Bioorg Med Chem Lett 2014; 24:4466-4471. [PMID: 25172419 PMCID: PMC4163096 DOI: 10.1016/j.bmcl.2014.07.091] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 10/24/2022]
Abstract
A novel synthesis of the translocator protein (TSPO) ligand 7-chloro-N,N,5-trimethyl-4-oxo-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide (SSR180575, 3) was achieved in four steps from commercially available starting materials. Focused structure-activity relationship development about the pyridazinoindole ring at the N3 position led to the discovery of 7-chloro-N,N,5-trimethyl-4-oxo-3(6-fluoropyridin-2-yl)-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide (14), a novel ligand of comparable affinity. Radiolabeling with fluorine-18 ((18)F) yielded 7-chloro-N,N,5-trimethyl-4-oxo-3(6-[(18)F]fluoropyridin-2-yl)-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide ([(18)F]-14) in high radiochemical yield and specific activity. In vivo studies of [(18)F]-14 revealed this agent as a promising probe for molecular imaging of glioma.
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Affiliation(s)
- Yiu-Yin Cheung
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States
| | - Michael L Nickels
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, United States
| | - Dewei Tang
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, United States
| | - Jason R Buck
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, United States
| | - H Charles Manning
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Program in Chemical and Physical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, United States; Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN 37232, United States
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9
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Kaynar G, Yurdakan G, Comert F, Yilmaz-Sipahi E. Effects of peripheral benzodiazepine receptor ligand Ro5-4864 in four animal models of acute lung injury. J Surg Res 2012; 182:277-84. [PMID: 23127280 DOI: 10.1016/j.jss.2012.10.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 10/01/2012] [Accepted: 10/12/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Acute lung injury (ALI) is a syndrome of inflammation and increased permeability of the blood-gas barrier. It is associated with high morbidity and mortality. Despite intensive research, treatments remain limited. The aim of the present study was to investigate the protective efficacy of a specific peripheral benzodiazepine receptor ligand, Ro5-4864, in experimental models of ALI in rats. METHODS ALI was generated by four different methods: (1) intravenous (tail vein) injection of Escherichia coli (0111:B4) lipopolysaccaride (LPS), (2) cecal ligation and puncture (CLP), (3) mesenteric ischemia/reperfusion, and (4) intraperitoneal injection of α-naphthylthiourea (ANTU). Ro5-4864 was administered to rats intraperitoneally 30 min before ANTU and LPS administration or intravenously 15 min before reperfusion and CLP. The levels of pulmonary edema (lung weight/body weight ratio) and pleural effusion were measured, and the severity of ALI was scored (0-3). RESULTS Ro5-4864 showed a dose-dependent and significant prophylactic effect on the ANTU-induced lung weight/body weight and pleural effusion/body weight ratios and histopathologic scores. Ro5-4864 also showed significant prophylactic effects against the LPS-induced lung weight/body weight ratio and histopathologic scores. Ro5-4864 significantly decreased the intra-alveolar edema and perialveolar hemorrhage scores in the CLP group. However, we found no prophylactic effect of Ro5-4864 on mesenteric ischemia/reperfusion-induced ALI at the dose used (2 mg/kg intraperitoneally). CONCLUSIONS These results have demonstrated, for the first time, a protective effect of Ro5-4864 on experimental ALI induced by ANTU, LPS, and CLP. Ro5-4864 might be a useful therapeutic agent for lung diseases, including ALI, in intensive care patients.
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Affiliation(s)
- Gulcan Kaynar
- Department of Pharmacology, Health Science Institute, Bulent Ecevit University, Kozlu, Zonguldak, Turkey
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In vivo imaging and quantitative analysis of TSPO in rat peripheral tissues using small-animal PET with [18F]FEDAC. Nucl Med Biol 2010; 37:853-60. [DOI: 10.1016/j.nucmedbio.2010.04.183] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 04/19/2010] [Accepted: 04/19/2010] [Indexed: 11/23/2022]
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11
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Ostuni MA, Issop L, Péranzi G, Walker F, Fasseu M, Elbim C, Papadopoulos V, Lacapere JJ. Overexpression of translocator protein in inflammatory bowel disease: potential diagnostic and treatment value. Inflamm Bowel Dis 2010; 16:1476-87. [PMID: 20222126 PMCID: PMC2930116 DOI: 10.1002/ibd.21250] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Inflammatory bowel diseases (IBDs), such as ulcerative colitis and Crohn's disease, are chronic inflammatory disorders that increase the risk for colorectal cancer. The mitochondrial translocator protein (TSPO) is a high-affinity drug- and cholesterol-binding protein expressed in the colon and its expression is increased in colon cancers. The aim of this study was to investigate TSPO expression in IBD biopsies and to establish an animal model of IBD to examine the role of TSPO. In addition, we evaluated the potential use of TSPO drug ligands in diagnosing and treating IBD. METHODS TSPO expression in IBD biopsies was evaluated using immunohistochemistry. IBD was induced in a rat experimental model via treatment with dextran sodium sulfate (DSS). Colon morphology, TSPO expression, and proinflammatory cytokine production were evaluated in addition to the effect of TSPO drug ligands on disease pathology. RESULTS TSPO protein levels were elevated in the enterocytes of IBD biopsies. TSPO expression was localized to the enterocyte mitochondria. DSS treatment induced a time-dependent phenotype mimicking IBD with tissue injury and subsequent tissue regeneration. Coadministration of DSS and the TSPO drug ligands PK 11195 or Ro5-4864 increased both the rate of colon ulceration and regeneration, whereas administration of the TSPO drug ligand flunitrazepam partially prevented this pathology. These data correlated with changes in proinflammatory cytokine plasma levels, as well as increased cytokine production and secretion from the colon. CONCLUSIONS TSPO may serve as a marker of the IBD repair process, and TSPO drug ligands should be further evaluated for IBD treatment.
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Affiliation(s)
- Mariano A Ostuni
- Unité INSERM U773, Centre de Recherche Biomédicale Bichat Beaujon CRB3, Université Paris 7 Denis Diderot, Paris, France.
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Synthesis, fluorine-18 radiolabeling, and in vitro characterization of 1-iodophenyl-N-methyl-N-fluoroalkyl-3-isoquinoline carboxamide derivatives as potential PET radioligands for imaging peripheral benzodiazepine receptor. Bioorg Med Chem 2008; 16:6145-55. [DOI: 10.1016/j.bmc.2008.04.046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 04/15/2008] [Accepted: 04/16/2008] [Indexed: 10/22/2022]
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Veiga S, Carrero P, Pernia O, Azcoitia I, Garcia-Segura LM. Translocator protein 18 kDa is involved in the regulation of reactive gliosis. Glia 2007; 55:1426-36. [PMID: 17674368 DOI: 10.1002/glia.20558] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Translocator protein (18 kDa) (TSPO), previously known as peripheral-type benzodiazepine receptor, is a critical component of the mitochondrial permeability transition pore. Brain inflammation results in the induction of the expression of TSPO in glial cells and some TSPO ligands decrease reactive gliosis after brain injury. However, since some TSPO ligands are neuroprotective, their effects on reactive gliosis may be the consequence of a reduced neurodegeneration. To assess whether TSPO ligands can modulate reactive gliosis in absence of neuronal death, we have tested their effects on the inflammatory response induced in the hippocampus of male rats by the intracerebroventricular infusion of lipopolysaccharide (LPS). LPS treatment did not induce neuronal death, assessed by Fluoro jade-B staining, but increased the number of cells immunoreactive for vimentin and MHC-II, used as markers of reactive astrocytes and reactive microglia, respectively. Furthermore, LPS produced an increase in the number of proliferating microglia. The TSPO ligand PK11195 reduced the number of MHC-II immunoreactive cells and the proliferation of microglia in LPS treated rats. In contrast, another TSPO ligand, Ro5-4864, did not significantly affect the response of microglia to LPS. Neither PK11195 nor Ro5-4864 affected the LPS-mediated increase in the number of vimentin-immunoreactive astrocytes at the time point studied, although PK11195 reduced vimentin immunoreactivity. These findings identify TSPO as a potential target for controlling neural inflammation, showing that the TSPO ligand PK11195 may reduce microglia activation by a mechanism that is independent of the regulation of neuronal survival.
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Green ML, Singh AV, Zhang Y, Nemeth KA, Sulik KK, Knudsen TB. Reprogramming of genetic networks during initiation of the Fetal Alcohol Syndrome. Dev Dyn 2007; 236:613-31. [PMID: 17200951 DOI: 10.1002/dvdy.21048] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Fetal Alcohol Spectrum Disorders (FASD) are birth defects that result from maternal alcohol use. We used a non a priori approach to prioritize candidate pathways during alcohol-induced teratogenicity in early mouse embryos. Two C57BL/6 substrains (B6J, B6N) served as the basis for study. Dosing pregnant dams with alcohol (2x 2.9 g/kg ethanol spaced 4 hr on day 8) induced FASD in B6J at a higher incidence than B6N embryos. Counter-exposure to PK11195 (4 mg/kg) significantly protected B6J embryos but slightly promoted FASD in B6N embryos. Microarray transcript profiling was performed on the embryonic headfold 3 hr after the first maternal alcohol injection (GEO data series accession GSE1074). This analysis revealed metabolic and cellular reprogramming that was substrain-specific and/or PK11195-dependent. Mapping ethanol-responsive KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways revealed down-regulation of ribosomal proteins and proteasome, and up-regulation of glycolysis and pentose phosphate pathway in B6N embryos; and significant up-regulation of tight junction, focal adhesion, adherens junction, and regulation of the actin cytoskeleton (and near-significant up-regulation of Wnt signaling and apoptosis) pathways in both substrains. Expression networks constructed computationally from these altered genes identified entry points for EtOH at several hubs (MAPK1, ALDH3A2, CD14, PFKM, TNFRSF1A, RPS6, IGF1, EGFR, PTEN) and for PK11195 at AKT1. Our findings are consistent with the growing view that developmental exposure to alcohol alters common signaling pathways linking receptor activation to cytoskeletal reorganization. The programmatic shift in cell motility and metabolic capacity further implies cell signals and responses that are integrated by the mitochondrial recognition site for PK11195.
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Affiliation(s)
- Maia L Green
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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15
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Sakai M, Fonseca ESM, Oloris SCS, Matsuzaki P, Otake AH, Leite KRM, Massoco CO, Dagli MLZ, Palermo-Neto J. Effects of peripheral-type benzodiazepine receptor ligands on Ehrlich tumor cell proliferation. Eur J Pharmacol 2006; 550:8-14. [PMID: 17027961 DOI: 10.1016/j.ejphar.2006.07.057] [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] [Received: 11/10/2005] [Revised: 07/11/2006] [Accepted: 07/26/2006] [Indexed: 11/18/2022]
Abstract
Peripheral-type benzodiazepine receptors have been found throughout the body, and particularly, in high numbers, in neoplastic tissues such as the ovary, liver, colon, breast, prostate and brain cancer. Peripheral-type benzodiazepine receptor expression has been associated with tumor malignity, and its subcellular localization is important to define its function in tumor cells. We investigated the presence of peripheral-type benzodiazepine receptors in Ehrlich tumor cells, and the in vitro effects of peripheral-type benzodiazepine receptors ligands on tumor cell proliferation. Our results demonstrate the presence of peripheral-type benzodiazepine receptor in the nucleus of Ehrlich tumor cells (85.53+/-12.60%). They also show that diazepam and Ro5-4864 (peripheral-type benzodiazepine receptor agonists) but not clonazepam (a molecule with low affinity for the peripheral-type benzodiazepine receptor) decreased the percentage of tumor cells in G0-G1 phases and increased that of cells in S-G2-M phases. The effects of those agonists were prevented by PK11195 (a peripheral-type benzodiazepine receptor antagonist) that did not produce effects by itself. Altogether, these data suggest that the presence of peripheral-type benzodiazepine receptor within the nucleus of Ehrlich tumor cells is associated with tumor malignity and proliferation capacity.
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Affiliation(s)
- Mônica Sakai
- Laboratory of Applied Pharmacology and Toxicology, School of Veterinary Medicine, University of São Paulo, São Paulo, SP, Brazil
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Ryu JK, Choi HB, McLarnon JG. Peripheral benzodiazepine receptor ligand PK11195 reduces microglial activation and neuronal death in quinolinic acid-injected rat striatum. Neurobiol Dis 2006; 20:550-61. [PMID: 15916899 DOI: 10.1016/j.nbd.2005.04.010] [Citation(s) in RCA: 263] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2005] [Revised: 03/18/2005] [Accepted: 04/08/2005] [Indexed: 11/24/2022] Open
Abstract
The effects of the peripheral benzodiazepine receptor (PBR) ligand, PK11195, were investigated in the rat striatum following the administration of quinolinic acid (QUIN). Intrastriatal QUIN injection caused an increase of PBR expression in the lesioned striatum as demonstrated by immunohistochemical analysis. Double immunofluorescent staining indicated PBR was primarily expressed in ED1-immunoreactive microglia but not in GFAP-immunoreactive astrocytes or NeuN-immunoreactive neurons. PK11195 treatment significantly reduced the level of microglial activation and the expression of pro-inflammatory cytokines and iNOS in QUIN-injected striatum. Oxidative-mediated striatal QUIN damage, characterized by increased expression of markers for lipid peroxidation (4-HNE) and oxidative DNA damage (8-OHdG), was significantly diminished by PK11195 administration. Furthermore, intrastriatal injection of PK11195 with QUIN significantly reduced striatal lesions induced by the excitatory amino acid and diminished QUIN-mediated caspase-3 activation in striatal neurons. These results suggest that inflammatory responses from activated microglia are damaging to striatal neurons and pharmacological targeting of PBR in microglia may be an effective strategy in protecting neurons in neurological disorders such as Huntington's disease.
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Affiliation(s)
- Jae K Ryu
- Department of Pharmacology and Therapeutics, Faculty of Medicine, 2176 Health Sciences Mall, The University of British Columbia, Vancouver, BC, Canada V6T 1Z3
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Knudsen TB, Green ML. Response characteristics of the mitochondrial DNA genome in developmental health and disease. ACTA ACUST UNITED AC 2005; 72:313-29. [PMID: 15662705 DOI: 10.1002/bdrc.20028] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This review focuses on mitochondrial biology in mammalian development; specifically, the dynamics of information transfer from nucleus to mitochondrion in the regulation of mitochondrial DNA genomic expression, and the reverse signaling of mitochondrion to nucleus as an adaptive response to the environment. Data from recent studies suggest that the capacity of embryonic cells to react to oxygenation involves a tradeoff between factors that influence prenatal growth/development and postnatal growth/function. For example, mitochondrial DNA replication and metabolic set points in nematodes may be determined by mitochondrial activity early in life. The mitochondrial drug PK11195, a ligand of the peripheral benzodiazepine receptor, has antiteratogenic and antidisease action in several developmental contexts in mice. Protein malnutrition during early life in rats can program mitochondrial DNA levels in adult tissues and, in humans, epidemiological data suggest an association between impaired fetal growth and insulin resistance. Taken together, these findings raise the provocative hypothesis that environmental programming of mitochondrial status during early life may be linked with diseases that manifest during adulthood. Genetic defects that affect mitochondrial function may involve the mitochondrial DNA genome directly (maternal inheritance) or indirectly (Mendelian inheritance) through nuclear-coded mitochondrial proteins. In a growing number of cases, the depletion of, or deletion in, mitochondrial DNA is seen to be secondary to mutation of key nuclear-coded mitochondrial proteins that affect mitochondrial DNA replication, expression, or stability. These defects of intergenomic regulation may disrupt the normal cross-talk or structural compartmentation of signals that ultimately regulate mitochondrial DNA integrity and copy number, leading to depletion of mitochondrial DNA.
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Affiliation(s)
- Thomas B Knudsen
- Department of Molecular, Cellular and Craniofacial Biology, School of Dentistry, Birth Defects Center, University of Louisville, Louisville, Kentucky 40202, USA.
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