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Guillemain G, Khemtemourian L, Brehat J, Morin D, Movassat J, Tourrel-Cuzin C, Lacapere JJ. TSPO in pancreatic beta cells and its possible involvement in type 2 diabetes. Biochimie 2024:S0300-9084(24)00143-3. [PMID: 38908539 DOI: 10.1016/j.biochi.2024.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 06/24/2024]
Abstract
Amyloidosis forms a large family of pathologies associated with amyloid deposit generated by the formation of amyloid fibrils or plaques. The amyloidogenic proteins and peptides involved in these processes are targeted against almost all organs. In brain they are associated with neurodegenerative disease, and the Translocator Protein (TSPO), overexpressed in these inflammatory conditions, is one of the target for the diagnostic. Moreover, TSPO ligands have been described as promising therapeutic drugs for neurodegenerative diseases. Type 2 diabetes, another amyloidosis, is due to a beta cell mass decrease that has been linked to hIAPP (human islet amyloid polypeptide) fibril formation, leading to the reduction of insulin production. In the present study, in a first approach, we link overexpression of TSPO and inflammation in potentially prediabetic patients. In a second approach, we observed that TSPO deficient rats have higher level of insulin secretion in basal conditions and more IAPP fibrils formation compared with wild type animals. In a third approach, we show that diabetogenic conditions also increase TSPO overexpression and IAPP fibril formation in rat beta pancreatic cell line (INS-1E). These data open the way for further studies in the field of type 2 diabetes treatment or prevention.
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Affiliation(s)
- Ghislaine Guillemain
- Sorbonne Université, Institut Hospitalo-Universitaire, INSERM UMR_S938, Institute of Cardiometabolism and Nutrition (ICAN), Centre de recherche de St-Antoine (CRSA), 27 rue de Chaligny, 75012 Paris, France.
| | | | - Juliette Brehat
- INSERM, U955, IMRB, équipe Ghaleh, Faculté de Médecine, UPEC, 94010 Créteil, France
| | - Didier Morin
- INSERM, U955, IMRB, équipe Ghaleh, Faculté de Médecine, UPEC, 94010 Créteil, France
| | - Jamileh Movassat
- Université Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Team "Biologie et Pathologie du Pancréas Endocrine", Paris, France
| | - Cécile Tourrel-Cuzin
- Université Paris Cité, Unité de Biologie Fonctionnelle et Adaptative, CNRS UMR 8251, Team "Biologie et Pathologie du Pancréas Endocrine", Paris, France
| | - Jean-Jacques Lacapere
- Sorbonne Université, Ecole normale supérieure, PSL University, CNRS, Laboratoire des Biomolécules, LBM, 75005 Paris, France.
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2
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Bréhat J, Issop L, Morin D. History of Tspo deletion and induction in vivo: Phenotypic outcomes under physiological and pathological situations. Biochimie 2024:S0300-9084(24)00051-8. [PMID: 38432291 DOI: 10.1016/j.biochi.2024.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/23/2024] [Accepted: 03/01/2024] [Indexed: 03/05/2024]
Abstract
The mitochondrial translocator protein (TSPO) is an outer mitochondrial protein membrane with high affinity for cholesterol. It is expressed in most tissues but is more particularly enriched in steroidogenic tissues. TSPO is involved in various biological mechanisms and TSPO regulation has been related to several diseases. However, despite a considerable number of published studies interested in TSPO over the past forty years, the precise function of the protein remains obscure. Most of the functions attributed to TSPO have been identified using pharmacological ligands of this protein, leading to much debate about the accuracy of these findings. In addition, research on the physiological role of TSPO has been hampered by the lack of in vivo deletion models. Studies to perform genetic deletion of Tspo in animal models have long been unsuccessful, which led to the conclusions that the deletion was deleterious and the gene essential to life. During the last decades, thanks to the significant technical advances allowing genome modification, several models of animal genetically modified for TSPO have been developed. These models have modified our view regarding TSPO and profoundly improved our fundamental knowledge on this protein. However, to date, they did not allow to elucidate the precise molecular function of TSPO and numerous questions persist concerning the physiological role of TSPO and its future as a therapeutic target. This article chronologically reviews the development of deletion and induction models of TSPO.
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Affiliation(s)
- Juliette Bréhat
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France
| | - Leeyah Issop
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France
| | - Didier Morin
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France.
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3
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Wongso H, Kurniawan A, Setiadi Y, Kusumaningrum CE, Widyasari EM, Wibawa TH, Mahendra I, Febrian MB, Sriyani ME, Halimah I, Daruwati I, Gunawan R, Achmad A, Nugraha DH, Lesmana R, Nugraha AS. Translocator Protein 18 kDa (TSPO): A Promising Molecular Target for Image-Guided Surgery of Solid Cancers. Adv Pharm Bull 2024; 14:86-104. [PMID: 38585455 PMCID: PMC10997928 DOI: 10.34172/apb.2024.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 08/26/2023] [Accepted: 10/08/2023] [Indexed: 04/09/2024] Open
Abstract
The translocator protein 18-kDa (TSPO) is a mitochondrial membrane protein that is previously identified as the peripheral benzodiazepine receptor (PBR). Furthermore, it plays a significant role in a diverse range of biochemical processes, including steroidogenesis, mitochondrial cholesterol transport, cell survival and death, cell proliferation, and carcinogenesis. Several investigations also reported its roles in various types of cancers, including colorectal, brain, breast, prostate, and lung cancers, as well as melanoma. According to a previous study, the expression of TSPO was upregulated in cancer cells, which corresponds to an aggressive phenotype and/or poor prognosis. Consequently, the potential for crafting diagnostic and prognostic tools with a focus on TSPO holds great potential. In this context, several radioligands designed to target this protein have been identified, and some of the candidates have advanced to clinical trials. In recent years, the use of hybrid probes with radioactive and fluorescence molecules for image-guided surgery has exhibited promising results in animal and human studies. This indicates that the approach can serve as a valuable surgical navigator during cancer surgery. The current hybrid probes are built from various molecular platforms, including small molecules, nanoparticles, and antibodies. Although several TSPO-targeted imaging probes have been developed, their development for image-guided surgery of cancers is still limited. Therefore, this review aims to highlight recent findings on the involvement of TSPO in carcinogenesis, as well as provide a new perspective on the potential application of TSPO-targeted hybrid probes for image-guided surgery.
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Affiliation(s)
- Hendris Wongso
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency, Jl. Ir. Soekarno KM 21, Jatinangor 45363, Indonesia
| | - Ahmad Kurniawan
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
| | - Yanuar Setiadi
- Research Center for Environmental and Clean Technology, Research Organization for Life Sciences and Environment, National Research and Innovation Agency, Puspiptek, Banten 15314, Indonesia
| | - Crhisterra E. Kusumaningrum
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
| | - Eva M. Widyasari
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
| | - Teguh H.A. Wibawa
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
| | - Isa Mahendra
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency, Jl. Ir. Soekarno KM 21, Jatinangor 45363, Indonesia
| | - Muhamad B. Febrian
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
| | - Maula E. Sriyani
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
| | - Iim Halimah
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
| | - Isti Daruwati
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency, Jl. Ir. Soekarno KM 21, Jatinangor 45363, Indonesia
- Department of Pharmaceutical Analysis and Medicinal Chemistry, Faculty of Pharmacy, Universitas Padjadjaran, Jl. Ir. Soekarno KM 21, Jatinangor 45363, Indonesia
| | - Rudi Gunawan
- Research Center for Radioisotope, Radiopharmaceutical, and Biodosimetry Technology, Research Organization for Nuclear Energy, National Research and Innovation Agency Republic of Indonesia, Puspiptek, Banten 15314, Indonesia
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency, Jl. Ir. Soekarno KM 21, Jatinangor 45363, Indonesia
- Department of Pharmaceutical Analysis and Medicinal Chemistry, Faculty of Pharmacy, Universitas Padjadjaran, Jl. Ir. Soekarno KM 21, Jatinangor 45363, Indonesia
| | - Arifudin Achmad
- Research Collaboration Center for Theranostic Radiopharmaceuticals, National Research and Innovation Agency, Jl. Ir. Soekarno KM 21, Jatinangor 45363, Indonesia
- Department of Nuclear Medicine and Molecular Theranostics, Faculty of Medicine, Universitas Padjadjaran, Bandung 40161
- Oncology and Stem Cells Working Group, Faculty of Medicine, Universitas Padjadjaran, Bandung 40161
| | | | - Ronny Lesmana
- Department of Biomedical Science, Faculty of Medicine, Universitas Padjadjaran, Jatinangor 45363, Indonesia
- Physiology Molecular, Division of Biological Activity, Central Laboratory, Universitas Padjadjaran, Jatinangor 45363, Indonesia
- Laboratory of Sciences, Graduate School, Universitas Padjadjaran, Bandung, Indonesia
| | - Ari S. Nugraha
- Drug Utilisation and Discovery Research Group, Faculty of Pharmacy, Universitas Jember, Jember 68121, Indonesia
- School of Chemistry and Molecular Biosciences, Molecular Horizons, University of Wollongong, Wollongong, New South Wales, 2522, Australia
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Sánchez-Quintero MJ, Rodríguez-Díaz C, Rodríguez-González FJ, Fernández-Castañer A, García-Fuentes E, López-Gómez C. Role of Mitochondria in Inflammatory Bowel Diseases: A Systematic Review. Int J Mol Sci 2023; 24:17124. [PMID: 38069446 PMCID: PMC10707203 DOI: 10.3390/ijms242317124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Revised: 11/27/2023] [Accepted: 11/30/2023] [Indexed: 12/18/2023] Open
Abstract
Mitochondria are key cellular organelles whose main function is maintaining cell bioenergetics by producing ATP through oxidative phosphorylation. However, mitochondria are involved in a much higher number of cellular processes. Mitochondria are the home of key metabolic pathways like the tricarboxylic acid cycle and β-oxidation of fatty acids, as well as biosynthetic pathways of key products like nucleotides and amino acids, the control of the redox balance of the cell and detoxifying the cell from H2S and NH3. This plethora of critical functions within the cell is the reason mitochondrial function is involved in several complex disorders (apart from pure mitochondrial disorders), among them inflammatory bowel diseases (IBD). IBD are a group of chronic, inflammatory disorders of the gut, mainly composed of ulcerative colitis and Crohn's disease. In this review, we present the current knowledge regarding the impact of mitochondrial dysfunction in the context of IBD. The role of mitochondria in both intestinal mucosa and immune cell populations are discussed, as well as the role of mitochondrial function in mechanisms like mucosal repair, the microbiota- and brain-gut axes and the development of colitis-associated colorectal cancer.
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Affiliation(s)
- María José Sánchez-Quintero
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, 29590 Málaga, Spain; (M.J.S.-Q.); (C.R.-D.); (A.F.-C.)
- Unidad de Gestión Clínica Cardiología y Cirugía Cardiovascular, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Cristina Rodríguez-Díaz
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, 29590 Málaga, Spain; (M.J.S.-Q.); (C.R.-D.); (A.F.-C.)
- Unidad de Gestión Clínica de Aparato Digestivo, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
| | - Francisco J. Rodríguez-González
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, 29590 Málaga, Spain; (M.J.S.-Q.); (C.R.-D.); (A.F.-C.)
- Unidad de Gestión Clínica de Aparato Digestivo, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
| | - Alejandra Fernández-Castañer
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, 29590 Málaga, Spain; (M.J.S.-Q.); (C.R.-D.); (A.F.-C.)
- Unidad de Gestión Clínica de Aparato Digestivo, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
| | - Eduardo García-Fuentes
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, 29590 Málaga, Spain; (M.J.S.-Q.); (C.R.-D.); (A.F.-C.)
- Unidad de Gestión Clínica de Aparato Digestivo, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBEREHD), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Carlos López-Gómez
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina-IBIMA Plataforma BIONAND, 29590 Málaga, Spain; (M.J.S.-Q.); (C.R.-D.); (A.F.-C.)
- Unidad de Gestión Clínica de Aparato Digestivo, Hospital Universitario Virgen de la Victoria, 29010 Málaga, Spain
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5
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Rezazadeh F, Kilcline AP, Viola NT. Imaging Agents for PET of Inflammatory Bowel Disease: A Review. J Nucl Med 2023; 64:1858-1864. [PMID: 37918865 PMCID: PMC10690123 DOI: 10.2967/jnumed.123.265935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/27/2023] [Indexed: 11/04/2023] Open
Abstract
Inflammatory bowel disease (IBD), which encompasses ulcerative colitis and Crohn disease, is a chronic inflammatory disorder resulting from an aberrant immune response, though its exact cause is unknown. The current mainstay standard of care for the diagnosis and surveillance of IBD is endoscopy. However, this methodology is invasive and images only superficial tissue structures, revealing very little about the molecular drivers of inflammation. Accordingly, there is an unmet need for noninvasive imaging tools that provide reliable and quantitative visualization of intestinal inflammation with high spatial and molecular specificity. In recent years, several PET agents for imaging IBD have been reported. Such agents allow noninvasive visualization and quantification of dynamic molecular inflammatory processes in vivo. This review focuses on recent advancements in the development of PET tracers for imaging biomarkers of interest in IBD pathogenesis, such as cell-surface molecules that are overexpressed on immune cells and cytokines that perpetuate inflammatory signaling.
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Affiliation(s)
- Farzaneh Rezazadeh
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, Michigan
| | - Aidan P Kilcline
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, Michigan
| | - Nerissa T Viola
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, Michigan
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6
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Liu S, Xia Y, Ji F. Advances in macrophage-targeting nanoparticles for the diagnosis and treatment of inflammatory bowel disease. Zhejiang Da Xue Xue Bao Yi Xue Ban 2023; 52:785-794. [PMID: 37986666 PMCID: PMC10764192 DOI: 10.3724/zdxbyxb-2023-0289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 09/20/2023] [Indexed: 11/22/2023]
Abstract
The pathogenesis of inflammatory bowel disease (IBD) is not fully elucidated. However, it has been considered that inflammatory macrophages may be involved in the imbalance of the intestinal mucosal immunity to regulate several signaling pathways, leading to IBD progression. The ratio of M1 to M2 subtypes of activated macrophages tends to increase in the inflamed intestinal section. There are challenges in the diagnosis and treatment of IBD, such as unsatisfactory specificity of imaging findings, low drug accumulation in the intestinal lesions, unstable therapeutic efficacy, and drug-related systemic toxicity. Recently developed nanoparticles may provide a new approach for the diagnosis and treatment of IBD. Nanoparticles targeted to macrophages can be used as contrast agents to improve the imaging quality or used as a drug delivery vector to increase the therapeutic efficiency of IBD. This article reviews the research progress on macrophage-targeting nanoparticles for the diagnosis and treatment of IBD to provide a reference for further research and clinical application.
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Affiliation(s)
- Sha Liu
- Department of Anesthesiology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
| | - Yi Xia
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Feng Ji
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
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7
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Scott AP, Henden A, Kennedy GA, Tey SK. PET assessment of acute gastrointestinal graft versus host disease. Bone Marrow Transplant 2023; 58:973-979. [PMID: 37537245 PMCID: PMC10471499 DOI: 10.1038/s41409-023-02038-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Revised: 06/29/2023] [Accepted: 07/07/2023] [Indexed: 08/05/2023]
Abstract
Acute gastrointestinal graft versus host disease (GI-GVHD) is a common complication following allogeneic haematopoietic cell transplantation (HCT), and is characterised by severe morbidity, frequent treatment-refractoriness, and high mortality. Early, accurate identification of GI-GVHD could allow for therapeutic interventions to ameliorate its severity, improve response rates and survival; however, standard endoscopic biopsy is inadequately informative in terms of diagnostic sensitivity or outcome prediction. In an era where rapid technological and laboratory advances have dramatically expanded our understanding of GI-GVHD biology and potential therapeutic targets, there is substantial scope for novel investigations that can precisely guide GI-GVHD management. In particular, the combination of tissue-based biomarker assessment (plasma cytokines, faecal microbiome) and molecular imaging by positron emission tomography (PET) offers the potential for non-invasive, real-time in vivo assessment of donor:recipient immune activity within the GI tract for GI-GVHD prediction or diagnosis. In this article, we review the evidence regarding GI-GVHD diagnosis, and examine the potential roles and translational opportunities posed by these novel diagnostic tools, with a focus on the evolving role of PET.
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Affiliation(s)
- Ashleigh P Scott
- Department of Haematology and Bone Marrow Transplant, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia.
- School of Medicine, The University of Queensland, Brisbane, QLD, Australia.
| | - Andrea Henden
- Department of Haematology and Bone Marrow Transplant, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- School of Medicine, The University of Queensland, Brisbane, QLD, Australia
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Glen A Kennedy
- Department of Haematology and Bone Marrow Transplant, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- School of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Siok-Keen Tey
- Department of Haematology and Bone Marrow Transplant, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
- School of Medicine, The University of Queensland, Brisbane, QLD, Australia
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
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8
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Duma L, Senicourt L, Rigaud B, Papadopoulos V, Lacapère JJ. Solid-state NMR study of structural heterogeneity of the apo WT mouse TSPO reconstituted in liposomes. Biochimie 2023; 205:73-85. [PMID: 36029902 DOI: 10.1016/j.biochi.2022.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/08/2022] [Accepted: 08/18/2022] [Indexed: 11/02/2022]
Abstract
In the last decades, ligand binding to human TSPO has been largely used in clinical neuroimaging, but little is known about the interaction mechanism. Protein conformational mobility plays a key role in the ligand recognition and both, ligand-free and ligand-bound structures, are mandatory for characterizing the molecular binding mechanism. In the absence of crystals for mammalian TSPO, we have exploited solid-state nuclear magnetic resonance (ssNMR) spectroscopy under magic-angle spinning (MAS) to study the apo form of recombinant mouse TSPO (mTSPO) reconstituted in lipids. This environment has been previously described to permit binding of its high-affinity drug ligand PK11195 and appears therefore favourable for the study of molecular dynamics. We have optimized the physical conditions to get the best resolution for MAS ssNMR spectra of the ligand-free mTSPO. We have compared and combined various ssNMR spectra to get dynamical information either for the lipids or for the mTSPO. Partial assignment of residue types suggests few agreements with the published solution NMR assignment of the PK11195-bound mTSPO in DPC detergent. Moreover, we were able to observe some lateral chains of aromatic residues that were not assigned in solution. 13C double-quantum NMR spectroscopy shows remarkable dynamics for ligand-free mTSPO in lipids which may have significant implications on the recognition of the ligand and/or other protein partners.
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Affiliation(s)
- Luminita Duma
- Champagne-Ardenne University, CNRS, ICMR UMR, 7312, Reims, France.
| | - Lucile Senicourt
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 4 Place Jussieu, F-75005, Paris, France
| | - Baptiste Rigaud
- CNRS Institut des Matériaux de Paris Centre (FR2482), 4 Place Jussieu, 75005, Paris, France
| | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, 90089, USA
| | - Jean-Jacques Lacapère
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), 4 Place Jussieu, F-75005, Paris, France
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9
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Jimenez IA, Stilin AP, Morohaku K, Hussein MH, Koganti PP, Selvaraj V. Mitochondrial translocator protein deficiency exacerbates pathology in acute experimental ulcerative colitis. Front Physiol 2022; 13:896951. [PMID: 36060674 PMCID: PMC9437295 DOI: 10.3389/fphys.2022.896951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 07/26/2022] [Indexed: 11/13/2022] Open
Abstract
In human patients and animal models of ulcerative colitis (UC), upregulation of the mitochondrial translocator protein (TSPO) in the colon is consistent with inflammation. Although the molecular function for TSPO remains unclear, it has been investigated as a therapeutic target for ameliorating UC pathology. In this study, we examined the susceptibility of Tspo gene-deleted (Tspo -/- ) mice to insults as provided by the dextran sodium sulfate (DSS)-induced acute UC model. Our results show that UC clinical signs and pathology were severely exacerbated in Tspo -/- mice compared to control Tspo fl/fl cohorts. Histopathology showed extensive inflammation and epithelial loss in Tspo -/- mice that caused an aggravated disease. Colonic gene expression in UC uncovered an etiology linked to precipitous loss of epithelial integrity and disproportionate mast cell activation assessed by tryptase levels in Tspo -/- colons. Evaluation of baseline homeostatic shifts in Tspo -/- colons revealed gene expression changes noted in elevated epithelial Cdx2, mast cell Cd36 and Mcp6, with general indicators of lower proliferation capacity and elevated mitochondrial fatty acid oxidation. These findings demonstrate that intact physiological TSPO function serves to limit inflammation in acute UC, and provide a systemic basis for investigating TSPO-targeting mechanistic therapeutics.
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Affiliation(s)
- Isabel A. Jimenez
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States,Department of Molecular and Comparative Pathobiology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Allison P. Stilin
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Kanako Morohaku
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States,School of Science and Technology, Institute of Agriculture, Shinshu University, Nagano, Japan
| | - Mahmoud H. Hussein
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Prasanthi P. Koganti
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States,*Correspondence: Vimal Selvaraj,
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[18F]GE-180 PET/CT assessment of enterocytic translocator protein (TSPO) over-expression: a pilot study in gastrointestinal GVHD. Bone Marrow Transplant 2022; 57:517-519. [DOI: 10.1038/s41409-022-01571-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 12/19/2021] [Accepted: 01/07/2022] [Indexed: 12/12/2022]
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11
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Tournier BB, Tsartsalis S, Ceyzériat K, Fraser BH, Grégoire MC, Kövari E, Millet P. Astrocytic TSPO Upregulation Appears Before Microglial TSPO in Alzheimer's Disease. J Alzheimers Dis 2021; 77:1043-1056. [PMID: 32804124 PMCID: PMC7683091 DOI: 10.3233/jad-200136] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Background: In vivo PET/SPECT imaging of neuroinflammation is primarily based on the estimation of the 18 kDa-translocator-protein (TSPO). However, TSPO is expressed by different cell types which complicates the interpretation. Objective: The present study evaluates the cellular origin of TSPO alterations in Alzheimer’s disease (AD). Methods: The TSPO cell origin was evaluated by combining radioactive imaging approaches using the TSPO radiotracer [125I]CLINDE and fluorescence-activated cell sorting, in a rat model of AD (TgF344-AD) and in AD subjects. Results: In the hippocampus of TgF344-AD rats, TSPO overexpression not only concerns glial cells but the increase is visible at 12 and 24 months in astrocytes and only at 24 months in microglia. In the temporal cortex of AD subjects, TSPO upregulation involved only glial cells. However, the mechanism of this upregulation appears different with an increase in the number of TSPO binding sites per cell without cell proliferation in the rat, and a microglial cell population expansion with a constant number of binding sites per cell in human AD. Conclusion: These data indicate an earlier astrocyte intervention than microglia and that TSPO in AD probably is an exclusive marker of glial activity without interference from other TSPO-expressing cells. This observation indicates that the interpretation of TSPO imaging depends on the stage of the pathology, and highlights the particular role of astrocytes.
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Affiliation(s)
- Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Switzerland
| | - Stergios Tsartsalis
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Switzerland
| | - Kelly Ceyzériat
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Switzerland.,Division of Nuclear medicine, University Hospitals of Geneva, Switzerland
| | - Ben H Fraser
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Sydney, NSW, Australia
| | - Marie-Claude Grégoire
- ANSTO LifeSciences, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Sydney, NSW, Australia
| | - Enikö Kövari
- Division of Geriatric Psychiatry, Department of Mental Health and Psychiatry, University Hospitals of Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Switzerland
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Switzerland.,Department of Psychiatry, University of Geneva, Switzerland
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12
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Hiser C, Montgomery BL, Ferguson-Miller S. TSPO protein binding partners in bacteria, animals, and plants. J Bioenerg Biomembr 2021; 53:463-487. [PMID: 34191248 PMCID: PMC8243069 DOI: 10.1007/s10863-021-09905-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 06/12/2021] [Indexed: 12/11/2022]
Abstract
The ancient membrane protein TSPO is phylogenetically widespread from archaea and bacteria to insects, vertebrates, plants, and fungi. TSPO’s primary amino acid sequence is only modestly conserved between diverse species, although its five transmembrane helical structure appears mainly conserved. Its cellular location and orientation in membranes have been reported to vary between species and tissues, with implications for potential diverse binding partners and function. Most TSPO functions relate to stress-induced changes in metabolism, but in many cases it is unclear how TSPO itself functions—whether as a receptor, a sensor, a transporter, or a translocator. Much evidence suggests that TSPO acts indirectly by association with various protein binding partners or with endogenous or exogenous ligands. In this review, we focus on proteins that have most commonly been invoked as TSPO binding partners. We suggest that TSPO was originally a bacterial receptor/stress sensor associated with porphyrin binding as its most ancestral function and that it later developed additional stress-related roles in eukaryotes as its ability to bind new partners evolved.
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Affiliation(s)
- Carrie Hiser
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA. .,Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA.
| | - Beronda L Montgomery
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA.,Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Shelagh Ferguson-Miller
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
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13
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Lv Q, Xu D, Ma J, Wang Y, Yang X, Zhao P, Ma L, Li Z, Yang W, Liu X, Yang G, Xing S. Uric acid drives intestinal barrier dysfunction through TSPO-mediated NLRP3 inflammasome activation. Inflamm Res 2021; 70:127-137. [PMID: 33074353 DOI: 10.1007/s00011-020-01409-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2020] [Revised: 09/28/2020] [Accepted: 10/01/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND AIM Intestinal epithelial dysfunction is the foundation of various intestinal and extra-intestinal diseases, while the effects and mechanism of uric acid on the intestinal barrier are little known. TSPO has been shown to be related to the generation of ROS and is involved in regulating inflammation, whether uric acid drives intestinal epithelial dysfunction through TSPO-mediated NLRP3 inflammasome activation is unknown. METHODS UOX gene knockout mouse (UOX-/-) were used for models of hyperuricemia. Fluorescein isothiocyanate (FITC)-labeled dextran was used to assess in vivo intestinal permeability. Serum lipopolysaccharide (LPS) and culture supernatants IL-1β were measured using ELISA Kit. IEC-6 exposed to different concentrations of uric acid was used for in vitro experiment. Protein content and mRNA were assessed using Western blotting and Q-PCR, respectively. Intracellular ROS was determined using flow cytometry and fluorescence microscope. Mitochondrial membrane potential was detected on an immunofluorescence. Small interfering RNA transfection was used to assess the interaction between translocator protein (TSPO) and NLRP3 inflammasome. N-acetyl-L-cysteine (NAC) was used as ROS scavenger. RESULTS Our results showed that hyperuricemia mice were characteristic by increased intestinal permeability. Hyperuricemia upregulated TSPO, increased production of ROS and activated NLRP3 inflammasome, which resulted in lower expression of occludin and claudin-1. In vitro, we showed that soluble uric acid alone increased the expression of TSPO, depolarized mitochondrial membrane potential, increased ROS release and activated NLRP3 inflammasome, which further reduced the expression of occludin and claudin-1. Silencing TSPO suppressed NLRP3 inflammasome activation and increased expression of claudin-1 and occludin, which was accompanied by lower levels of ROS. Scavenging ROS also significantly inhibited NLRP3 inflammasome activation without change of TSPO, indicating that TSPO-mediated NLRP3 inflammasome activation was dependent on ROS. CONCLUSIONS In conclusion, uric acid drives intestinal barrier dysfunction through TSPO-mediated NLRP3 inflammasome.
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Affiliation(s)
- Qiulan Lv
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Daxing Xu
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Jinfeng Ma
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Yan Wang
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Xiaomin Yang
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Peng Zhao
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Liang Ma
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Zhiyuan Li
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Wan Yang
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Xiu Liu
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China
| | - Guanpin Yang
- The Key Laboratory of Mariculture of Chinese Ministry of Education, Ocean University of China, Qingdao, 266003, People's Republic of China
| | - Shichao Xing
- Medical Research Center, Affiliated Hospital of Qingdao University, No. 167, Wutai Mountain Road, Qingdao, 266003, People's Republic of China.
- School of Cardiovascular Medicine and Science, King's College London, BHF Centre, London, SE5 9NU, UK.
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14
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Sharma A, Liaw K, Sharma R, Thomas AG, Slusher BS, Kannan S, Kannan RM. Targeting Mitochondria in Tumor-Associated Macrophages using a Dendrimer-Conjugated TSPO Ligand that Stimulates Antitumor Signaling in Glioblastoma. Biomacromolecules 2020; 21:3909-3922. [PMID: 32786523 PMCID: PMC8022998 DOI: 10.1021/acs.biomac.0c01033] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Mitochondria mediate critical cellular processes, including proliferation, apoptosis, and immune responses; as such, their dysfunction is pathogenic in many neurodegenerative disorders and cancers. In glioblastoma, targeted delivery of mitochondria-focused anticancer therapies has failed to translate into clinical success due to the nonspecific cellular localization, heterogeneity of receptor expression across patients, poor transport across biological barriers to reach the brain, tumor, and mitochondria, and systemic side effects. Strategies that can overcome brain and solid tumor barriers and selectively target mitochondria within specific cell types may lead to improvements in glioblastoma treatment. Developments in dendrimer-mediated nanomedicines have shown promise targeting tumor-associated macrophages (TAMs) in glioblastoma, following systemic administration. Here, we present a novel dendrimer conjugated to the translocator protein (18 kDa) (TSPO) ligand 5,7-dimethylpyrazolo[1,5-α]pyrimidin-3-ylacetamide (DPA). We developed a clickable DPA for conjugation on the dendrimer surface and demonstrated in vitro that the dendrimer-DPA conjugate (D-DPA) significantly increases dendrimer colocalization with mitochondria. Compared to free TSPO ligand PK11195, D-DPA stimulates greater antitumor immune signaling. In vivo, we show that D-DPA targets mitochondria specifically within TAMs following systemic administration. Our results demonstrate that dendrimers can achieve TAM-specific targeting in glioblastoma and can be further modified to target specific intracellular compartments for organelle-specific drug delivery.
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15
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Qiu ZK, Liu X, Chen Y, Wu RJ, Guan SF, Pan YY, Wang QB, Tang D, Zhu T, Chen JS. Translocator protein 18 kDa: a potential therapeutic biomarker for post traumatic stress disorder. Metab Brain Dis 2020; 35:695-707. [PMID: 32172519 DOI: 10.1007/s11011-020-00548-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 02/10/2020] [Indexed: 11/11/2022]
Abstract
Post traumatic stress disorder (PTSD) is widely regarded as a stress-related and trauma disorder. The symptoms of PTSD are characterized as a spectrum of vulnerabilities after the exposure to an extremely traumatic stressor. Considering as one of complex mental disorders, little progress has been made toward its diagnostic biomarkers, despite the involvement of PTSD has been studied. Many studies into the underlying neurobiology of PTSD implicated the dysfunction of neurosteroids biosynthesis and neuorinflammatory processes. Translocator protein 18 kDa (TSPO) has been considered as one of the promising therapeutic biomarkers for neurological stress disorders (like PTSD, depression, anxiety, et al) without the benzodiazepine-like side effects. This protein participates in the formation of neurosteroids and modulation of neuroinflammation. The review outlines current knowledge involving the role of TSPO in the neuropathology of PTSD and the anti-PTSD-like effects of TSPO ligands.
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Affiliation(s)
- Zhi-Kun Qiu
- Pharmaceutical Department of The First Affiliated Hospital of Guangdong Pharmaceutical University, Clinical Pharmacy Department of Guangdong Pharmaceutical University, Guangzhou, 510080, People's Republic of China
| | - Xu Liu
- Pharmacy Department of Medical Supplies Center of General Hospital of Chinese People's Armed Police Forces, Beijing, 100039, People's Republic of China
| | - Yong Chen
- Pharmaceutical Department of The First Affiliated Hospital of Guangdong Pharmaceutical University, Clinical Pharmacy Department of Guangdong Pharmaceutical University, Guangzhou, 510080, People's Republic of China
| | - Rong-Jia Wu
- Pharmaceutical Department of The First Affiliated Hospital of Guangdong Pharmaceutical University, Clinical Pharmacy Department of Guangdong Pharmaceutical University, Guangzhou, 510080, People's Republic of China
| | - Shi-Feng Guan
- Pharmaceutical Department of The First Affiliated Hospital of Guangdong Pharmaceutical University, Clinical Pharmacy Department of Guangdong Pharmaceutical University, Guangzhou, 510080, People's Republic of China
| | - Yun-Yun Pan
- Pharmaceutical Department of The First Affiliated Hospital of Guangdong Pharmaceutical University, Clinical Pharmacy Department of Guangdong Pharmaceutical University, Guangzhou, 510080, People's Republic of China
| | - Qian-Bo Wang
- Pharmaceutical Department of The First Affiliated Hospital of Guangdong Pharmaceutical University, Clinical Pharmacy Department of Guangdong Pharmaceutical University, Guangzhou, 510080, People's Republic of China
| | - Dan Tang
- Guangdong Provincial Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou, 510632, People's Republic of China
| | - Tao Zhu
- Guangdong Provincial Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou, 510632, People's Republic of China
| | - Ji-Sheng Chen
- Pharmaceutical Department of The First Affiliated Hospital of Guangdong Pharmaceutical University, Clinical Pharmacy Department of Guangdong Pharmaceutical University, Guangzhou, 510080, People's Republic of China.
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16
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Abstract
Redox signalling in the gastrointestinal mucosa is held in an intricate balance. Potent microbicidal mechanisms can be used by infiltrating immune cells, such as neutrophils, to protect compromised mucosae from microbial infection through the generation of reactive oxygen species. Unchecked, collateral damage to the surrounding tissue from neutrophil-derived reactive oxygen species can be detrimental; thus, maintenance and restitution of a breached intestinal mucosal barrier are paramount to host survival. Redox reactions and redox signalling have been studied for decades with a primary focus on contributions to disease processes. Within the past decade, an upsurge of exciting findings have implicated subtoxic levels of oxidative stress in processes such as maintenance of mucosal homeostasis, the control of protective inflammation and even regulation of tissue wound healing. Resident gut microbial communities have been shown to trigger redox signalling within the mucosa, which expresses similar but distinct enzymes to phagocytes. At the fulcrum of this delicate balance is the colonic mucosal epithelium, and emerging evidence suggests that precise control of redox signalling by these barrier-forming cells may dictate the outcome of an inflammatory event. This Review will address both the spectrum and intensity of redox activity pertaining to host-immune and host-microbiota crosstalk during homeostasis and disease processes in the gastrointestinal tract.
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17
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The Mitochondrial Genes BAK1, FIS1 and SFN are Linked with Alterations in Mitochondrial Membrane Potential in Barrett's Esophagus. Int J Mol Sci 2018; 19:ijms19113483. [PMID: 30404157 PMCID: PMC6275077 DOI: 10.3390/ijms19113483] [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: 10/08/2018] [Revised: 10/27/2018] [Accepted: 11/03/2018] [Indexed: 01/20/2023] Open
Abstract
Barrett's esophagus and esophageal cancer lack prognostic markers that allow the tailoring of personalized medicine and biomarkers with potential to provide insight into treatment response. This study aims to characterize mitochondrial function across the metaplasia-dysplasia-adenocarcinoma disease sequence in Barrett's esophagus and examines the functional effect of manipulating mitochondrial genes. Mitochondrial genes of interest were validated in in vitro cell lines across the metaplasia (QH), dysplasia (GO) and adenocarcinoma (OE33) sequence and in in vivo patient tissue samples. These genes were subsequently knocked down in QH and OE33 cells and the functional effect of siRNA-induced knockdown on reactive oxygen species production, mitochondrial mass, mitochondrial membrane potential and cellular metabolism was investigated. Three global mitochondrial genes (BAK1, FIS1 and SFN) were differentially altered across the in vivo Barrett's disease sequence. We also demonstrate that knockdown of BAK1, FIS1 and SFN in vitro resulted in significant alterations in mitochondrial membrane potential; however, no differences in reactive oxygen species or mitochondrial mass were observed. Furthermore, knockdown of these genes in esophageal adenocarcinoma cells significantly altered cellular metabolism. In conclusion, we found that differential expression of BAK1, FIS1, and SFN were altered across the Barrett's disease sequence and manipulation of these genes elicited significant effects on mitochondrial membrane potential.
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18
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Kawahara Y, Mitsui K, Niwa T, Morimoto N, Kawaharada S, Katsumata S. Translocator protein 18kDa antagonist ameliorates stress-induced stool abnormality and abdominal pain in rodent stress models. Neurogastroenterol Motil 2018; 30:e13425. [PMID: 30069991 DOI: 10.1111/nmo.13425] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 06/18/2018] [Indexed: 12/17/2022]
Abstract
BACKGROUND Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder characterized by abdominal pain and abnormal bowel habits, both of which are exacerbated by psychological stress. The translocator protein 18kDa (TSPO) is a marker of reactive gliosis in a number of central nervous system (CNS) diseases and responsible for many cellular functions, including neurosteroidogenesis. Although it has been reported that psychological stress disturbs neurosteroids levels, the pathophysiological relevance of TSPO in IBS is poorly understood. METHODS We examined the effects of a TSPO antagonist, ONO-2952, on stress-induced stool abnormality and abdominal pain in rats, and on anxiety-related behavior induced by cholecystokinin. KEY RESULTS Oral administration of ONO-2952 attenuated stress-induced defecation and rectal hyperalgesia in rats with an efficacy equivalent to that of a 5-HT3 receptor antagonist. In addition, ONO-2952 suppressed cholecystokinin-induced anxiety-like behavior with an efficacy equivalent to that of psychotropic drugs. On the other hand, ONO-2952 did not affect spontaneous defecation, gastrointestinal transit, visceral nociceptive threshold, and neurosteroid production in non-stressed rats even at a dose 10 times higher than its effective dose in the stress models. CONCLUSIONS AND INFERENCES These results suggest that TSPO antagonism results in antistress action, and that ONO-2952 is a promising candidate for IBS without side effects associated with current treatment.
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Affiliation(s)
- Y Kawahara
- Discovery Research Laboratories I, ONO Pharmaceutical Co., Ltd., Osaka, Japan
| | - K Mitsui
- Discovery Research Laboratories I, ONO Pharmaceutical Co., Ltd., Osaka, Japan
| | - T Niwa
- Discovery Research Laboratories I, ONO Pharmaceutical Co., Ltd., Osaka, Japan
| | - N Morimoto
- Discovery Research Laboratories I, ONO Pharmaceutical Co., Ltd., Osaka, Japan
| | - S Kawaharada
- Discovery Research Laboratories I, ONO Pharmaceutical Co., Ltd., Osaka, Japan
| | - S Katsumata
- Discovery Research Laboratories I, ONO Pharmaceutical Co., Ltd., Osaka, Japan
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19
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McNeela AM, Bernick C, Hines RM, Hines DJ. TSPO regulation in reactive gliotic diseases. J Neurosci Res 2018; 96:978-988. [PMID: 29315754 DOI: 10.1002/jnr.24212] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 11/29/2017] [Accepted: 12/06/2017] [Indexed: 12/19/2022]
Abstract
The brain is the most metabolically active organ in the body. This high metabolic demand is apparent in that 60% of the brain is comprised of mitochondria-enriched cells. A disruption of the brain's ability to meet this immense metabolic demand is central to the pathogenesis of a multitude of neurological disorders, which range from depression to Alzheimer's disease. Central to these pathologies are glial signaling and energy metabolism cascades regulating apoptosis and inflammation. Thus, diseases causing inflammation and disruption of metabolism can be correlated with glial reactivity. Acutely, reactive gliosis provides a mechanism for limiting the progression of a disease. Following chronic activation, the ability of reactive gliosis to limit disease progression decreases and, in some cases, transitions into a harmful state. The necessity for a noninvasive biomarker of disease in the brain has linked reactive gliosis with an upregulation of translocator protein (TSPO). TSPO is an 18kDa protein that is both a therapeutic target for multiple acute and chronic neuroinflammatory diseases and the leading biomarker for Alzheimer's disease. Although a central function of TSPO is not well known, the protein was named for its ability to translocate cholesterol. Increased TSPO expression is an indicator of disrupted metabolic activity and increased reactive oxygen production. The changes in TSPO expression levels both temporally and spatially relate to the pathogenesis of stroke, Alzheimer's disease, traumatic brain injury, and depression. Therefore, research into the basic function and potential therapeutics targeting TSPO will have broad implications for many diseases of the brain.
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Affiliation(s)
- Adam M McNeela
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV
| | - Charles Bernick
- Cleveland Clinic Lou Ruvo Center for Brain Health, Las Vegas, NV
| | - Rochelle M Hines
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV
| | - Dustin J Hines
- Department of Psychology, University of Nevada Las Vegas, Las Vegas, NV
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Choi BM. Characteristics of electroencephalogram signatures in sedated patients induced by various anesthetic agents. J Dent Anesth Pain Med 2017; 17:241-251. [PMID: 29349346 PMCID: PMC5766087 DOI: 10.17245/jdapm.2017.17.4.241] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 12/04/2017] [Accepted: 12/07/2017] [Indexed: 11/21/2022] Open
Abstract
Devices that monitor the depth of hypnosis based on the electroencephalogram (EEG) have long been commercialized, and clinicians use these to titrate the dosage of hypnotic agents. However, these have not yet been accepted as standard monitoring devices for anesthesiology. The primary reason is that the use of these monitoring devices does not completely prevent awareness during surgery, and the development of these devices has not taken into account the neurophysiological mechanisms of hypnotic agents, thus making it possible to show different levels of unconsciousness in the same brain status. An alternative is to monitor EEGs that are not signal processed with numerical values presented by these monitoring devices. Several studies have reported that power spectral analysis alone can distinguish the effects of different hypnotic agents on consciousness changes. This paper introduces the basic concept of power spectral analysis and introduces the EEG characteristics of various hypnotic agents that are used in sedation.
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Affiliation(s)
- Byung-Moon Choi
- Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea
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21
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Evaluating [ 11C]PBR28 PET for Monitoring Gut and Brain Inflammation in a Rat Model of Chemically Induced Colitis. Mol Imaging Biol 2017; 19:68-76. [PMID: 27402092 PMCID: PMC5209392 DOI: 10.1007/s11307-016-0979-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Purpose Ulcerative colitis (UC) is a chronic inflammatory disease of the colon that affects an increasing number of patients. High comorbidity is observed between UC and other diseases in which inflammation may be involved, including brain diseases such as cognitive impairment, mental disorders, anxiety, and depression. To investigate the increased occurrence of these brain diseases in patients with UC, non-invasive methods for monitoring peripheral and central inflammation could be applied. Therefore, the goal of this study is to assess the feasibility of monitoring gut and brain inflammation in a rat model of chemically induced colitis by positron emission tomography (PET) with [11C]PBR28, a tracer targeting the translocator protein (TSPO), which is upregulated when microglia and macrophages are activated. Procedures Colitis was induced in rats by intra-rectal injection of 2,4,6-trinitrobenzenesulfonic acid (TNBS). Rats with colitis and healthy control animals were subjected to [11C]PBR28 PET of the abdomen followed by ex vivo biodistribution in order to assess whether inflammation in the gut could be detected. Another group of rats with colitis underwent repetitive [11C]PBR28 PET imaging of the brain to investigate the development of neuroinflammation. Results Eleven days after TNBS injection, ex vivo biodistribution studies demonstrated increased [11C]PBR28 uptake in the inflamed cecum and colon of rats with colitis as compared to healthy controls, whereas PET imaging did not show any difference between groups at any time. Similarly, repetitive PET imaging of the brain did not reveal any neuroinflammation induced by the TNBS administration in the colon. In contrast, significantly increased [11C]PBR28 uptake in cerebellum could be detected in ex vivo biodistribution studies on day 11. Conclusion Inflammation in both the gut and the brain of rats with chemically induced colitis was observed by ex vivo biodistribution. However, these effects could not be detected by [11C]PBR28 PET imaging in our colitis model, which is likely due to spill-over effects and insufficient resolution of the PET camera.
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TSPO PET Imaging: From Microglial Activation to Peripheral Sterile Inflammatory Diseases? CONTRAST MEDIA & MOLECULAR IMAGING 2017; 2017:6592139. [PMID: 29114179 PMCID: PMC5632884 DOI: 10.1155/2017/6592139] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 08/01/2017] [Accepted: 08/07/2017] [Indexed: 02/07/2023]
Abstract
Peripheral sterile inflammatory diseases (PSIDs) are a heterogeneous group of disorders that gathers several chronic insults involving the cardiovascular, respiratory, gastrointestinal, or musculoskeletal system and wherein inflammation is the cornerstone of the pathophysiology. In PSID, timely characterization and localization of inflammatory foci are crucial for an adequate care for patients. In brain diseases, in vivo positron emission tomography (PET) exploration of inflammation has matured over the last 20 years, through the development of radiopharmaceuticals targeting the translocator protein-18 kDa (TSPO) as molecular biomarkers of activated microglia. Recently, TSPO has been introduced as a possible molecular target for PSIDs PET imaging, making this protein a potential biomarker to address disease heterogeneity, to assist in patient stratification, and to contribute to predicting treatment response. In this review, we summarized the major research advances recently made in the field of TSPO PET imaging in PSIDs. Promising preliminary results have been reported in bowel, cardiovascular, and rheumatic inflammatory diseases, consolidated by preclinical studies. Limitations of TSPO PET imaging in PSIDs, regarding both its large expression in healthy peripheral tissues, unlike in central nervous system, and the production of peripheral radiolabeled metabolites, are also discussed, regarding their possible consequences on TSPO PET signal's quantification.
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Caobelli F, Evangelista L, Quartuccio N, Familiari D, Altini C, Castello A, Cucinotta M, Di Dato R, Ferrari C, Kokomani A, Laghai I, Laudicella R, Migliari S, Orsini F, Pignata SA, Popescu C, Puta E, Ricci M, Seghezzi S, Sindoni A, Sollini M, Sturiale L, Svyridenka A, Vergura V, Alongi P, Young AIMN Working Group. Role of molecular imaging in the management of patients affected by inflammatory bowel disease: State-of-the-art. World J Radiol 2016; 8:829-845. [PMID: 27843542 PMCID: PMC5084061 DOI: 10.4329/wjr.v8.i10.829] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 06/30/2016] [Accepted: 08/29/2016] [Indexed: 02/06/2023] Open
Abstract
AIM To present the current state-of-the art of molecular imaging in the management of patients affected by inflammatory bowel disease (IBD).
METHODS A systematic review of the literature was performed in order to find important original articles on the role of molecular imaging in the management of patients affected by IBD. The search was updated until February 2016 and limited to articles in English.
RESULTS Fifty-five original articles were included in this review, highlighting the role of single photon emission tomography and positron emission tomography.
CONCLUSION To date, molecular imaging represents a useful tool to detect active disease in IBD. However, the available data need to be validated in prospective multicenter studies on larger patient samples.
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Glover LE, Lee JS, Colgan SP. Oxygen metabolism and barrier regulation in the intestinal mucosa. J Clin Invest 2016; 126:3680-3688. [PMID: 27500494 DOI: 10.1172/jci84429] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Mucosal surfaces are lined by epithelial cells and provide an important barrier to the flux of antigens from the outside. This barrier is provided at a number of levels, including epithelial junctional complexes, mucus production, and mucosa-derived antimicrobials. Tissue metabolism is central to the maintenance of homeostasis in the mucosa. In the intestine, for example, baseline pO2 levels are uniquely low due to counter-current blood flow and the presence of large numbers of bacteria. As such, hypoxia and HIF signaling predominates normal intestinal metabolism and barrier regulation during both homeostasis and active inflammation. Contributing factors that elicit important adaptive responses within the mucosa include the transcriptional regulation of tight junction proteins, metabolic regulation of barrier components, and changes in autophagic flux. Here, we review recent literature around the topic of hypoxia and barrier function in health and during disease.
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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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Issop L, Ostuni MA, Lee S, Laforge M, Péranzi G, Rustin P, Benoist JF, Estaquier J, Papadopoulos V, Lacapère JJ. Translocator Protein-Mediated Stabilization of Mitochondrial Architecture during Inflammation Stress in Colonic Cells. PLoS One 2016; 11:e0152919. [PMID: 27054921 PMCID: PMC4824355 DOI: 10.1371/journal.pone.0152919] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/21/2016] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Chronic inflammation of the gastrointestinal tract increasing the risk of cancer has been described to be linked to the high expression of the mitochondrial translocator protein (18 kDa; TSPO). Accordingly, TSPO drug ligands have been shown to regulate cytokine production and to improve tissue reconstruction. We used HT-29 human colon carcinoma cells to evaluate the role of TSPO and its drug ligands in tumor necrosis factor (TNF)-induced inflammation. TNF-induced interleukin (IL)-8 expression, coupled to reactive oxygen species (ROS) production, was followed by TSPO overexpression. TNF also destabilized mitochondrial ultrastructure, inducing cell death by apoptosis. Treatment with the TSPO drug ligand PK 11195 maintained the mitochondrial ultrastructure, reducing IL-8 and ROS production and cell death. TSPO silencing and overexpression studies demonstrated that the presence of TSPO is essential to control IL-8 and ROS production, so as to maintain mitochondrial ultrastructure and to prevent cell death. Taken together, our data indicate that inflammation results in the disruption of mitochondrial complexes containing TSPO, leading to cell death and epithelia disruption. SIGNIFICANCE This work implicates TSPO in the maintenance of mitochondrial membrane integrity and in the control of mitochondrial ROS production, ultimately favoring tissue regeneration.
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Affiliation(s)
- Leeyah Issop
- Sorbonne Universités – Université Pierre et Marie Curie Université de Paris VI, École Normale Supérieure – PSL Research University, Département de Chimie, CNRS UMR 7203 LBM, 4 Place Jussieu, F-75005, Paris, France
- The Research Institute of the McGill University Health Center and the Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Mariano A. Ostuni
- INSERM UMRS 1134, Institut National de la Transfusion Sanguine, 6 rue Alexandre Cabanel, Université Paris 7 Denis Diderot, F-75015 Paris, France
| | - Sunghoon Lee
- The Research Institute of the McGill University Health Center and the Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | | | - Gabriel Péranzi
- Sorbonne Universités – Université Pierre et Marie Curie Université de Paris VI, École Normale Supérieure – PSL Research University, Département de Chimie, CNRS UMR 7203 LBM, 4 Place Jussieu, F-75005, Paris, France
| | - Pierre Rustin
- INSERM UMR 1141, Hôpital Robert Debré, and Université Paris 7 Denis Diderot, F-75019, Paris, France
| | - Jean-François Benoist
- INSERM UMR 1141, Hôpital Robert Debré, and Université Paris 7 Denis Diderot, F-75019, Paris, France
| | - Jérome Estaquier
- CNRS FR 3636, Université Paris Descartes, Paris, France
- Université Laval, Faculté de Médecine, Département de microbiologie-infectiologie et d’immunologie, Quebec City, Quebec, G1V06A, Canada
| | - Vassilios Papadopoulos
- The Research Institute of the McGill University Health Center and the Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Jean-Jacques Lacapère
- Sorbonne Universités – Université Pierre et Marie Curie Université de Paris VI, École Normale Supérieure – PSL Research University, Département de Chimie, CNRS UMR 7203 LBM, 4 Place Jussieu, F-75005, Paris, France
- * E-mail:
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Bernards N, Pottier G, Thézé B, Dollé F, Boisgard R. In vivo evaluation of inflammatory bowel disease with the aid of μPET and the translocator protein 18 kDa radioligand [18F]DPA-714. Mol Imaging Biol 2015; 17:67-75. [PMID: 25015387 PMCID: PMC4544644 DOI: 10.1007/s11307-014-0765-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Purpose The purpose of the study was to validate [18F]DPA-714, a translocator protein (TSPO) 18 kDa radioligand, as a probe to non-invasively quantify the inflammatory state in inflammatory bowel disease (IBD) animal models. Procedures Quantitative positron emission tomography (PET) imaging of intestinal inflammation was conducted with 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) a glucose metabolism surrogate marker and [18F]DPA-714 a ligand of the 18 kDa TSPO, on two IBD models. The first model was induced using dextran sodium sulfate (DSS), creating global inflammation in the colon. The second model was induced by rectally administering trinitrobenzenesulfonic acid (TNBS), creating local and acute inflammation. Results The level of inflammation was analyzed using PET imaging on days 7 and 8. The analysis obtained with [18F]DPA-714, yielded a significant difference between the DSS treated (0.50 ± 0.17%ID/cc) and non-treated rats (0.35 ± 0.15%ID/cc). [18F]FDG on the other hand did not yield a significant difference. We did observe a mean glucose consumption in the colon increase from 0.40 ± 0.11 %ID/cc to 0.54 ± 0.17 %ID/cc. In the TNBS model, the uptake level of [18 F]DPA-714 increased significantly from 0.46 ± 0.23%ID/cc for the non-treated group, to 1.30 ± 0.62%ID/cc for those treated. PET signal was correlated with increased TSPO expression at cellular level. Conclusions Results indicate that [18F]DPA-714 is suitable for studying inflammation in IBD models. [18F]DPA-714 could be a good molecular probe to non-invasively evaluate the level and localization of inflammation. Moreover, in vivo imaging using this TSPO ligand is potentially a powerful tool to stage and certainly to follow the evolution and therapeutic efficiency at molecular level within this disease family.
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Wu Y, Briley K, Tao X. Nanoparticle-based imaging of inflammatory bowel disease. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2015; 8:300-15. [PMID: 26371464 DOI: 10.1002/wnan.1357] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 05/11/2015] [Accepted: 05/23/2015] [Indexed: 12/16/2022]
Affiliation(s)
- Yingwei Wu
- Department of Radiology; Shanghai Ninth People's Hospital, Shanghai Jiaotong University, School of Medicine; Shanghai China
- Department of Radiology; Shanghai East Hospital, Tongji University, School of Medicine; Shanghai China
| | - Karen Briley
- Department of Radiology, Wright Center of Innovation and Biomedical Imaging; The Ohio State University; Columbus OH USA
| | - Xiaofeng Tao
- Department of Radiology; Shanghai Ninth People's Hospital, Shanghai Jiaotong University, School of Medicine; Shanghai China
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Lin R, Angelin A, Da Settimo F, Martini C, Taliani S, Zhu S, Wallace DC. Genetic analysis of dTSPO, an outer mitochondrial membrane protein, reveals its functions in apoptosis, longevity, and Ab42-induced neurodegeneration. Aging Cell 2014; 13:507-18. [PMID: 24977274 PMCID: PMC4076708 DOI: 10.1111/acel.12200] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The outer mitochondrial membrane (OMM) protein, the translocator protein 18 kDa (TSPO), formerly named the peripheral benzodiazepine receptor (PBR), has been proposed to participate in the pathogenesis of neurodegenerative diseases. To clarify the TSPO function, we identified the Drosophila homolog, CG2789/dTSPO, and studied the effects of its inactivation by P-element insertion, RNAi knockdown, and inhibition by ligands (PK11195, Ro5-4864). Inhibition of dTSPO inhibited wing disk apoptosis in response to γ-irradiation or H2O2 exposure, as well as extended male fly lifespan and inhibited Aβ42-induced neurodegeneration in association with decreased caspase activation. Therefore, dTSPO is an essential mediator of apoptosis in Drosophila and plays a central role in controlling longevity and neurodegenerative disease, making it a promising drug target.
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Affiliation(s)
- Ran Lin
- Department of Physiology and Pathophysiology School of Basic Medical Sciences Health Science Center Peking University Beijing 100191China
- Center for Mitochondrial and Epigenomic Medicine Children's Hospital of Philadelphia Research Institute Philadelphia PA 19104USA
| | - Alessia Angelin
- Center for Mitochondrial and Epigenomic Medicine Children's Hospital of Philadelphia Research Institute Philadelphia PA 19104USA
| | | | - Claudia Martini
- Dipartimento di Farmacia Università di Pisa via Bonanno 656126Pisa Italy
| | - Sabrina Taliani
- Dipartimento di Farmacia Università di Pisa via Bonanno 656126Pisa Italy
| | - Shigong Zhu
- Department of Physiology and Pathophysiology School of Basic Medical Sciences Health Science Center Peking University Beijing 100191China
| | - Douglas C. Wallace
- Center for Mitochondrial and Epigenomic Medicine Children's Hospital of Philadelphia Research Institute Philadelphia PA 19104USA
- Department of Pathology and Laboratory Medicine Perelman School of Medicine University of Pennsylvania Philadelphia PA 19104USA
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Translocator protein 18 kDa negatively regulates inflammation in microglia. J Neuroimmune Pharmacol 2014; 9:424-37. [PMID: 24687172 DOI: 10.1007/s11481-014-9540-6] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2013] [Accepted: 03/10/2014] [Indexed: 12/22/2022]
Abstract
Translocator protein 18 kDa (TSPO) is a mitochondrial outer membrane protein. Although TSPO expression is up-regulated during neuroinflammation, the role of TSPO and its signaling mechanisms in regulation of neuroinflammation remains to be elucidated at the molecular level. Here we demonstrate that TSPO is a negative regulator of neuroinflammation in microglia. Over-expression of TSPO decreased production of pro-inflammatory cytokines upon lipopolysaccharide treatment while TSPO knock-down had the opposite effect. Anti-inflammatory activity of TSPO is also supported by increased expression of alternatively activated M2 stage-related genes. These data suggest that up-regulation of TSPO level during neuroinflammation may be an adaptive response mechanism. We also provide the evidence that the repressive activity of TSPO is at least partially mediated by the attenuation of NF-κB activation. Neurodegenerative diseases are characterized by loss of specific subsets of neurons at the particular anatomical regions of the central nervous system. Cause of neuronal death is still largely unknown, but it is becoming clear that neuroinflammation plays a significant role in the pathophysiology of neurodegenerative diseases. Understanding the mechanisms underlying the inhibitory effects of TSPO on neuroinflammation can contribute to the therapeutic design for neurodegenerative diseases.
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Gatliff J, East D, Crosby J, Abeti R, Harvey R, Craigen W, Parker P, Campanella M. TSPO interacts with VDAC1 and triggers a ROS-mediated inhibition of mitochondrial quality control. Autophagy 2014; 10:2279-96. [PMID: 25470454 PMCID: PMC4502750 DOI: 10.4161/15548627.2014.991665] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 09/17/2014] [Accepted: 09/22/2014] [Indexed: 01/03/2023] Open
Abstract
The 18-kDa TSPO (translocator protein) localizes on the outer mitochondrial membrane (OMM) and participates in cholesterol transport. Here, we report that TSPO inhibits mitochondrial autophagy downstream of the PINK1-PARK2 pathway, preventing essential ubiquitination of proteins. TSPO abolishes mitochondrial relocation of SQSTM1/p62 (sequestosome 1), and consequently that of the autophagic marker LC3 (microtubule-associated protein 1 light chain 3), thus leading to an accumulation of dysfunctional mitochondria, altering the appearance of the network. Independent of cholesterol regulation, the modulation of mitophagy by TSPO is instead dependent on VDAC1 (voltage-dependent anion channel 1), to which TSPO binds, reducing mitochondrial coupling and promoting an overproduction of reactive oxygen species (ROS) that counteracts PARK2-mediated ubiquitination of proteins. These data identify TSPO as a novel element in the regulation of mitochondrial quality control by autophagy, and demonstrate the importance for cell homeostasis of its expression ratio with VDAC1.
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Key Words
- ATP5B, ATP synthase, H+ transporting, mitochondrial F1 complex, β subunit
- DAPI, 4’, 6-diamidino-2-phenylindole
- DHE, dihydroethidium
- DNM1L, dynamin 1-like
- FCCP, carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone
- GAPDH, glyceraldehyde-3-phosphate dehydrogenase
- GSH, glutathione
- MAP1LC3/LC3, microtubule-associated protein 1 light chain 3
- MCB, monochlorobimane
- MEFs, mouse embryonic fibroblasts
- MnTBAP, manganese [III] tetrakis (4-benzoic acid) porphyrin
- MβCD, methyl-β-cyclodextrin
- NRF1, nuclear respiratory factor 1
- OMM, outer mitochondrial membrane
- PARK2
- PBS, phosphate-buffered saline
- PINK1, PTEN-induced putative kinase 1
- PRKCE, protein kinase C, epsilon
- RM, recording medium
- ROS
- ROS, reactive oxygen species
- RT, room temperature
- SQSTM1, sequestosome 1
- TFAM, transcription factor A, mitochondrial
- TMRM, tetramethylrhodamine methyl ester
- TSPO
- TSPO, translocator protein
- VDAC1, voltage-dependent anion channel 1
- YFP, yellow fluorescent protein
- mitochondria
- mitophagy
- mtRFP, mitochondrially targeted red fluorescent protein
- nsc, nonsilencing control
- siRNA, small interfering ribonucleic acid
- ubiquitin
- Δψm, mitochondrial membrane potential
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Affiliation(s)
- Jemma Gatliff
- Department of Comparative Biomedical Sciences; The Royal Veterinary College; University of London; London, UK
| | - Daniel East
- Department of Comparative Biomedical Sciences; The Royal Veterinary College; University of London; London, UK
| | - James Crosby
- Department of Comparative Biomedical Sciences; The Royal Veterinary College; University of London; London, UK
| | | | - Robert Harvey
- Department of Pharmacology; UCL School of Pharmacy; London, UK
| | - William Craigen
- Department of Molecular and Human Genetics; Baylor College of Medicine; Houston, TX USA
| | - Peter Parker
- London Research Institute; Lincoln's Inn Fields Laboratories; London, UK
- Division of Cancer Studies; King's College; London, UK
| | - Michelangelo Campanella
- Department of Comparative Biomedical Sciences; The Royal Veterinary College; University of London; London, UK
- University College London Consortium for Mitochondrial Research; London, UK
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Abstract
BACKGROUND Mucosal healing (MH) decreases the relapse risk in patients with inflammatory bowel disease, but the role of dietary supplementation in this process has been poorly investigated. Here, we investigated the effect of an amino acid mixture supplement on rat MH. METHODS Colitis was induced using 5% of dextran sodium sulfate for 6 days. Then, rats received a mixture of threonine (0.50 g/d), methionine (0.31 g/d), and monosodium glutamate (0.57 g/d) or an isonitrogenous amount of alanine (control group). Colons were recovered after colitis induction and after dietary supplementation for measuring colon characteristics, myeloperoxidase, cytokine gene expression, glutathione content, protein synthesis rate, and for histological analysis. Short-chain fatty acids were measured in the colonic content. RESULTS Colitis induction resulted in anorexia, thickening and shortening of the colon, and ulceration. Colonic cytokine expression and neutrophil infiltration were increased. An increased amount of water and a decreased amount of butyrate, propionate, and acetate were measured in the colonic content. Supplementation with the amino acid mixture coincided with a reduced protein synthesis rate in the colon compatible with the observed increased colonic MH. Mucosal regeneration/re-epithelialization was visible within 3 days after colitis induction at a time when mucosal inflammation was severe. Histological analysis revealed an increased regeneration/re-epithelialization after 10-day supplementation. In contrast, the spontaneous resolution of inflammation was not affected by the supplementation. CONCLUSIONS Amino acid supplementation ameliorates colonic MH but not mucosal inflammatory status. Our data sustain the use of adjuvant dietary intervention on initiated intestinal MH.
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Boone DL, Teitell MA. The other genome: mitochondrial DNA and protection from experimental colitis. Gastroenterology 2013; 145:933-5. [PMID: 24063944 DOI: 10.1053/j.gastro.2013.09.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Affiliation(s)
- David L Boone
- Section of Gastroenterology, Department of Medicine, University of Chicago, Chicago, Illinois.
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Wang HJ, Fan J, Papadopoulos V. Translocator protein (Tspo) gene promoter-driven green fluorescent protein synthesis in transgenic mice: an in vivo model to study Tspo transcription. Cell Tissue Res 2012; 350:261-75. [PMID: 22868914 DOI: 10.1007/s00441-012-1478-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 06/26/2012] [Indexed: 12/11/2022]
Abstract
Translocator protein (TSPO), previously known as the peripheral-type benzodiazepine receptor, is a ubiquitous drug- and cholesterol-binding protein primarily found in the outer mitochondrial membrane as part of a mitochondrial cholesterol transport complex. TSPO is present at higher levels in steroid-synthesizing and rapidly proliferating tissues and its biological role has been mainly linked to mitochondrial function, steroidogenesis and cell proliferation/apoptosis. Aberrant TSPO levels have been linked to multiple diseases, including cancer, endocrine disorders, brain injury, neurodegeneration, ischemia-reperfusion injury and inflammatory diseases. Investigation of the functions of this protein in vitro and in vivo have been mainly carried out using high-affinity drug ligands, such as isoquinoline carboxamides and benzodiazepines and more recently, gene silencing methods. To establish a model to study the regulation of Tspo transcription in vivo, we generated a transgenic mouse model expressing green fluorescent protein (GFP) from Aequorea coerulescens under control of the Tspo promoter region (Tspo-AcGFP). The expression profiles of Tspo-AcGFP, endogenous TSPO and Tspo mRNA were found to be well-correlated. Tspo-AcGFP synthesis in the transgenic mice was seen in almost every tissue examined and as with TSPO in wild-type mice, Tspo-AcGFP was highly expressed in steroidogenic cells of the endocrine and reproductive systems, epithelial cells of the digestive system, skeletal muscle and other organs. In summary, this transgenic Tspo-AcGFP mouse model recapitulates endogenous Tspo expression patterns and could be a useful, tractable tool for monitoring the transcriptional regulation and function of Tspo in live animal experiments.
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Affiliation(s)
- Hui-Jie Wang
- The Research Institute of the McGill University Health Center, McGill University, Montréal, Québec, H3A 1A4, Canada
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