1
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Firth W, Robb JL, Stewart D, Pye KR, Bamford R, Oguro-Ando A, Beall C, Ellacott KLJ. Regulation of astrocyte metabolism by mitochondrial translocator protein 18 kDa. J Neurochem 2024. [PMID: 38482552 DOI: 10.1111/jnc.16089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 02/15/2024] [Accepted: 02/17/2024] [Indexed: 03/26/2024]
Abstract
The mitochondrial translocator protein 18 kDa (TSPO) has been linked to functions from steroidogenesis to regulation of cellular metabolism and is an attractive therapeutic target for chronic CNS inflammation. Studies in Leydig cells and microglia indicate that TSPO function may vary between cells depending on their specialized roles. Astrocytes are critical for providing trophic and metabolic support in the brain. Recent work has highlighted that TSPO expression increases in astrocytes under inflamed conditions and may drive astrocyte reactivity. Relatively little is known about the role TSPO plays in regulating astrocyte metabolism and whether this protein is involved in immunometabolic processes in these cells. Using TSPO-deficient (TSPO-/- ) mouse primary astrocytes in vitro (MPAs) and a human astrocytoma cell line (U373 cells), we performed extracellular metabolic flux analyses. We found that TSPO deficiency reduced basal cellular respiration and attenuated the bioenergetic response to glucopenia. Fatty acid oxidation was increased, and lactate production was reduced in TSPO-/- MPAs and U373 cells. Co-immunoprecipitation studies revealed that TSPO forms a complex with carnitine palmitoyltransferase 1a in U373 and MPAs, presenting a mechanism wherein TSPO may regulate FAO in these cells. Compared to TSPO+/+ cells, in TSPO-/- MPAs we observed attenuated tumor necrosis factor release following 3 h lipopolysaccharide (LPS) stimulation, which was enhanced at 24 h post-LPS stimulation. Together these data suggest that while TSPO acts as a regulator of metabolic flexibility, TSPO deficiency does not appear to modulate the metabolic response of MPAs to inflammation, at least in response to the model used in this study.
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Affiliation(s)
- Wyn Firth
- Department of Clinical and Biomedical Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Josephine L Robb
- Department of Clinical and Biomedical Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Daisy Stewart
- Department of Clinical and Biomedical Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Katherine R Pye
- Department of Clinical and Biomedical Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Rosemary Bamford
- Department of Clinical and Biomedical Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Asami Oguro-Ando
- Department of Clinical and Biomedical Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Craig Beall
- Department of Clinical and Biomedical Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Kate L J Ellacott
- Department of Clinical and Biomedical Sciences, University of Exeter Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
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2
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Twitto-Greenberg R, Liraz-Zaltsman S, Michaelson DM, Liraz O, Lubitz I, Atrakchi-Baranes D, Shemesh C, Ashery U, Cooper I, Harari A, Harats D, Schnaider-Beeri M, Shaish A. 9-cis beta-carotene-enriched diet significantly improved cognition and decreased Alzheimer's disease neuropathology and neuroinflammation in Alzheimer's disease-like mouse models. Neurobiol Aging 2024; 133:16-27. [PMID: 38381472 DOI: 10.1016/j.neurobiolaging.2023.09.005] [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: 02/16/2023] [Revised: 09/10/2023] [Accepted: 09/17/2023] [Indexed: 02/22/2024]
Abstract
A significant progressive decline in beta-carotene (βC) levels in the brain is associated with cognitive impairment and a higher prevalence of Alzheimer's disease (AD). In this study, we investigated whether the administration of 9-cis beta-carotene (9CBC)-rich powder of the alga Dunaliella bardawil, the best-known source of βC in nature, inhibits the development of AD-like neuropathology and cognitive deficits. We demonstrated that in 3 AD mouse models, Tg2576, 5xFAD, and apoE4, 9CBC treatment improved long- and short-term memory, decreased neuroinflammation, and reduced the prevalence of β-amyloid plaques and tau hyperphosphorylation. These findings suggest that 9CBC has the potential to be an effective preventive and symptomatic AD therapy.
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Affiliation(s)
- Rachel Twitto-Greenberg
- The Bert W. Strassburger Metabolic Center, Sheba Medical Center, Ramat-Gan, Israel; The Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel; The Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat-Gan, Israel
| | - Sigal Liraz-Zaltsman
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat-Gan, Israel; Department of Pharmacology, Institute for Drug Research, Hebrew University, Jerusalem, Israel; Institutes for Health and Medical Professions, Department of Sports Therapy, Ono Academic College, Kyrat-Ono, Israel
| | - Daniel M Michaelson
- The Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Ori Liraz
- The Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Irit Lubitz
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat-Gan, Israel
| | | | - Chen Shemesh
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat-Gan, Israel
| | - Uri Ashery
- The Department of Neurobiology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Itzik Cooper
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Ramat-Gan, Israel; Institutes for Health and Medical Professions, Department of Sports Therapy, Ono Academic College, Kyrat-Ono, Israel
| | - Ayelet Harari
- The Bert W. Strassburger Metabolic Center, Sheba Medical Center, Ramat-Gan, Israel
| | - Dror Harats
- The Bert W. Strassburger Metabolic Center, Sheba Medical Center, Ramat-Gan, Israel; The Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | | | - Aviv Shaish
- The Bert W. Strassburger Metabolic Center, Sheba Medical Center, Ramat-Gan, Israel; Department of Life Sciences, Achva Academic College, Be'er-Tuvia Regional Council, Israel.
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3
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Wu Z, Chen X, Wu S, Liu Z, Li H, Mai K, Peng Y, Zhang H, Zhang X, Zheng Z, Fu Z, Chen D. Transcriptome analysis reveals the impact of NETs activation on airway epithelial cell EMT and inflammation in bronchiolitis obliterans. Sci Rep 2023; 13:19226. [PMID: 37932341 PMCID: PMC10628238 DOI: 10.1038/s41598-023-45617-y] [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: 06/09/2023] [Accepted: 10/21/2023] [Indexed: 11/08/2023] Open
Abstract
Bronchiolitis obliterans (BO) is a chronic airway disease that was often indicated by the pathological presentation of narrowed and irreversible airways. However, the molecular mechanisms of BO pathogenesis remain unknown. Although neutrophil extracellular traps (NETs) can contribute to inflammatory disorders, their involvement in BO is unclear. This study aims to identify potential signaling pathways in BO by exploring the correlations between NETs and BO. GSE52761 and GSE137169 datasets were downloaded from gene expression omnibus (GEO) database. A series of bioinformatics analyses such as differential expression analysis, gene ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and gene set enrichment analysis (GSEA) were performed on GSE52761 and GSE137169 datasets to identify BO potential signaling pathways. Two different types of BO mouse models were constructed to verify NETs involvements in BO. Additional experiments and bioinformatics analysis using human small airway epithelial cells (SAECs) were also performed to further elucidate differential genes enrichment with their respective signaling pathways in BO. Our study identified 115 differentially expressed genes (DEGs) that were found up-regulated in BO. Pathway enrichment analysis revealed that these genes were primarily involved in inflammatory signaling processes. Besides, we found that neutrophil extracellular traps (NETs) were formed and activated during BO. Our western blot analysis on lung tissue from BO mice further confirmed NETs activation in BO, where neutrophil elastase (NE) and myeloperoxidase (MPO) expression were found significantly elevated. Transcriptomic and bioinformatics analysis of NETs treated-SAECs also revealed that NETs-DEGs were primarily associated through inflammatory and epithelial-to-mesenchymal transition (EMT) -related pathways. Our study provides novel clues towards the understanding of BO pathogenesis, in which NETs contribute to BO pathogenesis through the activation of inflammatory and EMT associated pathways. The completion of our study will provide the basis for potential novel therapeutic targets in BO treatment.
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Affiliation(s)
- Zhongji Wu
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Xiaowen Chen
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Shangzhi Wu
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Zhenwei Liu
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Hongwei Li
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Kailin Mai
- Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Yinghui Peng
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Haidi Zhang
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Xiaodie Zhang
- Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Zhaocong Zheng
- Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Zian Fu
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, People's Republic of China
| | - Dehui Chen
- The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, 510000, People's Republic of China.
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Firth W, Robb JL, Stewart D, Pye KR, Bamford R, Oguro-Ando A, Beall C, Ellacott KLJ. Regulation of astrocyte metabolism by mitochondrial translocator protein 18kDa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.29.560159. [PMID: 37873215 PMCID: PMC10592862 DOI: 10.1101/2023.09.29.560159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The mitochondrial translocator protein 18kDa (TSPO) has been linked to a variety of functions from steroidogenesis to regulation of cellular metabolism and is an attractive therapeutic target for chronic CNS inflammation. Studies in the periphery using Leydig cells and hepatocytes, as well as work in microglia, indicate that the function of TSPO may vary between cells depending on their specialised roles. Astrocytes are critical for providing trophic and metabolic support in the brain as part of their role in maintaining brain homeostasis. Recent work has highlighted that TSPO expression increases in astrocytes under inflamed conditions and may drive astrocyte reactivity. However, relatively little is known about the role TSPO plays in regulating astrocyte metabolism and whether this protein is involved in immunometabolic processes in these cells. Using TSPO-deficient (TSPO-/-) mouse primary astrocytes in vitro (MPAs) and a human astrocytoma cell line (U373 cells), we performed metabolic flux analyses. We found that loss of TSPO reduced basal astrocyte respiration and increased the bioenergetic response to glucose reintroduction following glucopenia, while increasing fatty acid oxidation (FAO). Lactate production was significantly reduced in TSPO-/- astrocytes. Co-immunoprecipitation studies in U373 cells revealed that TSPO forms a complex with carnitine palmitoyltransferase 1a, which presents a mechanism wherein TSPO may regulate FAO in astrocytes. Compared to TSPO+/+ cells, inflammation induced by 3h lipopolysaccharide (LPS) stimulation of TSPO-/- MPAs revealed attenuated tumour necrosis factor release, which was enhanced in TSPO-/- MPAs at 24h LPS stimulation. Together these data suggest that while TSPO acts as a regulator of metabolic flexibility in astrocytes, loss of TSPO does not appear to modulate the metabolic response of astrocytes to inflammation, at least in response to the stimulus/time course used in this study.
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Affiliation(s)
- Wyn Firth
- University of Exeter Medical School, Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Josephine L Robb
- University of Exeter Medical School, Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Daisy Stewart
- University of Exeter Medical School, Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Katherine R Pye
- University of Exeter Medical School, Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Rosemary Bamford
- University of Exeter Medical School, Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Asami Oguro-Ando
- University of Exeter Medical School, Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Craig Beall
- University of Exeter Medical School, Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Kate LJ Ellacott
- University of Exeter Medical School, Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
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5
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Amara R, Zeineh N, Monga S, Weizman A, Gavish M. The Effect of the Classical TSPO Ligand PK 11195 on In Vitro Cobalt Chloride Model of Hypoxia-like Condition in Lung and Brain Cell Lines. Biomolecules 2022; 12:1397. [PMID: 36291606 PMCID: PMC9599342 DOI: 10.3390/biom12101397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/24/2022] [Accepted: 09/27/2022] [Indexed: 11/18/2022] Open
Abstract
The mitochondrial translocator protein (TSPO) is a modulator of the apoptotic pathway involving reactive oxygen species (ROS) generation, mitochondrial membrane potential (Δψm) collapse, activation of caspases, and eventually initiation of the apoptotic process. In this in vitro study, H1299 lung cells and BV-2 microglial cells were exposed to the hypoxia-like effect of CoCl2 with or without PK 11195. Exposing the H1299 cells to 0.5 mM CoCl2 for 24 h resulted in decreases in cell viability (63%, p < 0.05), elevation of cardiolipin peroxidation levels (38%, p < 0.05), mitochondrial membrane potential depolarization (13%, p < 0.001), and apoptotic cell death (117%, p < 0.05). Pretreatment with PK 11195 (25 µM) exhibited significant protective capacity on CoCl2-induced alterations in the mentioned processes. Exposure of BV-2 cells to increasing concentrations of CoCl2 (0.3, 0.5, 0.7 mM) for 4 h resulted in alterations in the same cellular processes. These alterations were obtained in a dose-dependent manner, except the changes in caspases 3 and 9. The novel ligands as well as PK 1195 attenuated the in vitro hypoxia-like effects of CoCl2. It appears that the TSPO ligand PK 11195 can prevent CoCl2-induced cellular damage in both non-neuronal and brain cell lines, and they may offer a novel approach to the treatment of hypoxia-related lung and brain diseases in some cases that fail to respond to conventional therapies.
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Affiliation(s)
- Rula Amara
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Nidal Zeineh
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Sheelu Monga
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
| | - Abraham Weizman
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Research Unit, Geha Mental Health Center and Felsenstein Medical Research Center, Petah Tikva 4910002, Israel
| | - Moshe Gavish
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel
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6
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Liu Q, Huang Y, Duan M, Yang Q, Ren B, Tang F. Microglia as Therapeutic Target for Radiation-Induced Brain Injury. Int J Mol Sci 2022; 23:ijms23158286. [PMID: 35955439 PMCID: PMC9368164 DOI: 10.3390/ijms23158286] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 12/10/2022] Open
Abstract
Radiation-induced brain injury (RIBI) after radiotherapy has become an increasingly important factor affecting the prognosis of patients with head and neck tumor. With the delivery of high doses of radiation to brain tissue, microglia rapidly transit to a pro-inflammatory phenotype, upregulate phagocytic machinery, and reduce the release of neurotrophic factors. Persistently activated microglia mediate the progression of chronic neuroinflammation, which may inhibit brain neurogenesis leading to the occurrence of neurocognitive disorders at the advanced stage of RIBI. Fully understanding the microglial pathophysiology and cellular and molecular mechanisms after irradiation may facilitate the development of novel therapy by targeting microglia to prevent RIBI and subsequent neurological and neuropsychiatric disorders.
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Affiliation(s)
- Qun Liu
- The School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou 434023, China; (Q.L.); (Y.H.)
| | - Yan Huang
- The School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou 434023, China; (Q.L.); (Y.H.)
| | - Mengyun Duan
- Department of Pharmacology, School of Medicine, Yangtze University, Jingzhou 434023, China; (M.D.); (Q.Y.)
| | - Qun Yang
- Department of Pharmacology, School of Medicine, Yangtze University, Jingzhou 434023, China; (M.D.); (Q.Y.)
| | - Boxu Ren
- The School of Basic Medicine, Health Science Center, Yangtze University, Jingzhou 434023, China; (Q.L.); (Y.H.)
- Correspondence: (B.R.); (F.T.)
| | - Fengru Tang
- Radiation Physiology Laboratory, Singapore Nuclear Research and Safety Initiative, National University of Singapore, Singapore 138602, Singapore
- Correspondence: (B.R.); (F.T.)
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7
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The mitochondrial translocator protein (TSPO): a key multifunctional molecule in the nervous system. Biochem J 2022; 479:1455-1466. [PMID: 35819398 DOI: 10.1042/bcj20220050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 12/12/2022]
Abstract
Translocator protein (TSPO, 18 kDa), formerly known as peripheral benzodiazepine receptor, is an evolutionary well-conserved protein located on the outer mitochondrial membrane. TSPO is involved in a variety of fundamental physiological functions and cellular processes. Its expression levels are regulated under many pathological conditions, therefore, TSPO has been proposed as a tool for diagnostic imaging and an attractive therapeutic drug target in the nervous system. Several synthetic TSPO ligands have thus been explored as agonists and antagonists for innovative treatments as neuroprotective and regenerative agents. In this review, we provide state-of-the-art knowledge of TSPO functions in the brain and peripheral nervous system. Particular emphasis is placed on its contribution to important physiological functions such as mitochondrial homeostasis, energy metabolism and steroidogenesis. We also report how it is involved in neuroinflammation, brain injury and diseases of the nervous system.
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8
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Monga S, Fares B, Yashaev R, Melamed D, Kahana M, Fares F, Weizman A, Gavish M. The Effect of Natural-Based Formulation (NBF) on the Response of RAW264.7 Macrophages to LPS as an In Vitro Model of Inflammation. J Fungi (Basel) 2022; 8:jof8030321. [PMID: 35330323 PMCID: PMC8955716 DOI: 10.3390/jof8030321] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 12/12/2022] Open
Abstract
Macrophages are some of the most important immune cells in the organism and are responsible for creating an inflammatory immune response in order to inhibit the passage of microscopic foreign bodies into the blood stream. Sometimes, their activation can be responsible for chronic inflammatory diseases such as asthma, tuberculosis, hepatitis, sinusitis, inflammatory bowel disease, and viral infections. Prolonged inflammation can damage the organs or may lead to death in serious conditions. In the present study, RAW264.7 macrophages were exposed to lipopolysaccharide (LPS; 20 ng/mL) and simultaneously treated with 20 µg/mL of natural-based formulation (NBF), mushroom–cannabidiol extract). Pro-inflammatory cytokines, chemokines, and other inflammatory markers were analyzed. The elevations in the presence of interleukin-6 (IL-6), cycloxygenase-2 (COX-2), C-C motif ligand-5 (CCL5), and nitrite response, following exposure to LPS, were completely inhibited by NBF administration. IL-1β and tumor necrosis factor alpha (TNF-α) release were inhibited by 3.9-fold and 1.5-fold, respectively. No toxic effect of NBF, as assessed by lactate dehydrogenase (LDH) release, was observed. Treatment of the cells with NBF significantly increased the mRNA levels of TLR2, and TLR4, but not NF-κB. Thus, it appears that the NBF possesses anti-inflammatory and immunomodulatory effects which can attenuate the release of pro-inflammatory markers. NBF may be a candidate for the treatment of acute and chronic inflammatory diseases and deserves further investigation.
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Affiliation(s)
- Sheelu Monga
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel; (S.M.); (F.F.)
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel; (R.Y.); (M.K.)
| | - Basem Fares
- Cannabotech Ltd., 3 Arik Einstein St., Herzliya 4659071, Israel; (B.F.); (D.M.)
| | - Rami Yashaev
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel; (R.Y.); (M.K.)
| | - Dov Melamed
- Cannabotech Ltd., 3 Arik Einstein St., Herzliya 4659071, Israel; (B.F.); (D.M.)
| | - Meygal Kahana
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel; (R.Y.); (M.K.)
| | - Fuad Fares
- Department of Human Biology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel; (S.M.); (F.F.)
| | - Abraham Weizman
- Sackler Faculty of Medicine, Felsenstein Medical Research Center, Tel Aviv University, Tel Aviv 6997801, Israel;
- Research Unit, Geha Mental Health Center, Petah Tikva 4910002, Israel
| | - Moshe Gavish
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel; (R.Y.); (M.K.)
- Correspondence:
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9
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Tsetlin V, Haufe Y, Safronova V, Serov D, Shadamarshan P, Son L, Shelukhina I, Kudryavtsev D, Kryukova E, Kasheverov I, Nicke A, Utkin Y. Interaction of α9α10 Nicotinic Receptors With Peptides and Proteins From Animal Venoms. Front Cell Neurosci 2022; 15:765541. [PMID: 35002625 PMCID: PMC8732759 DOI: 10.3389/fncel.2021.765541] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/15/2021] [Indexed: 12/13/2022] Open
Abstract
Unlike most neuronal nicotinic acetylcholine receptor (nAChR) subunits, α7, α9, and α10 subunits are able to form functional homo- or heteromeric receptors without any β subunits. While the α7 subtype is widely distributed in the mammalian brain and several peripheral tissues, α9 and α9α10 nAChRs are mainly found in the cochlea and immune cells. α-Conotoxins that specifically block the α9α10 receptor showed anti-nociceptive and anti-hyperalgesic effects in animal models. Hence, this subtype is considered a drug target for analgesics. In contrast to the α9α10-selective α-conotoxins, the three-finger toxin α-bungarotoxin inhibits muscle-type and α7 nAChRs in addition to α9α10 nAChRs. However, the selectivity of α-neurotoxins at the α9α10 subtype was less intensively investigated. Here, we compared the potencies of α-conotoxins and α-neurotoxins at the human α9α10 nAChR by two-electrode voltage clamp analysis upon expression in Xenopus oocytes. In addition, we analyzed effects of several α9α10-selective α-conotoxins on mouse granulocytes from bone marrow to identify possible physiological functions of the α9α10 nAChR subtype in these cells. The α-conotoxin-induced IL-10 release was measured upon LPS-stimulation. We found that α-conotoxins RgIA, PeIA, and Vc1.1 enhance the IL-10 expression in granulocytes which might explain the known anti-inflammatory and associated analgesic activities of α9α10-selective α-conotoxins. Furthermore, we show that two long-chain α-neurotoxins from the cobra Naja melanoleuca venom that were earlier shown to bind to muscle-type and α7 nAChRs, also inhibit the α9α10 subtype at nanomolar concentrations with one of them showing a significantly slower dissociation from this receptor than α-bungarotoxin.
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Affiliation(s)
- Victor Tsetlin
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Yves Haufe
- Faculty of Medicine, Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Valentina Safronova
- Laboratory of Cellular Neurobiology, Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - Dmitriy Serov
- Laboratory of Cellular Neurobiology, Institute of Cell Biophysics, Russian Academy of Sciences, Pushchino, Russia
| | - PranavKumar Shadamarshan
- Faculty of Medicine, Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Lina Son
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Irina Shelukhina
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Denis Kudryavtsev
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Elena Kryukova
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Igor Kasheverov
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Annette Nicke
- Faculty of Medicine, Walther Straub Institute of Pharmacology and Toxicology, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Yuri Utkin
- Department of Molecular Neuroimmune Signaling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
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10
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The Neuro-Protective Effects of the TSPO Ligands CB86 and CB204 on 6-OHDA-Induced PC12 Cell Death as an In Vitro Model for Parkinson’s Disease. BIOLOGY 2021; 10:biology10111183. [PMID: 34827176 PMCID: PMC8615274 DOI: 10.3390/biology10111183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/09/2021] [Accepted: 11/11/2021] [Indexed: 11/21/2022]
Abstract
Simple Summary Aims and objectives: For this study, we hypothesized that the two TSPO ligands CB86 and CB204 can inhibit cellular apoptosis and necrosis by in in vitro cellular PD model of undifferentiated PC12 cells exposed to 6-hydroxydopamine (6-OHDA, 80 µM). The two TSPO ligands CB86 and CB204 seem to suppress cell death of PC12 induced by 6-OHDA. The results may be relevant to the use of these two TSPO ligands as therapeutic options for neurodegenerative diseases like Parkinson disease (PD). Results: The two ligands normalized significantly (57% and 52%, respectively, from 44%; whereas the control was 68%) cell proliferation at different time points from 0–24 h. As compared to control, the red count was increased up to 57-fold whereas CB86 and CB204 inhibited to 2.7-fold and 3.2-fold, respectively. CB86 and CB204 inhibited also normalized the cell viability up to 1.8-fold after the exposure to 6-OHDA, as assessed by XTT assay. The two TSPO ligands also inhibited apoptosis significantly (1.3-fold for both) as assessed by apopxin green staining. Conclusion: It appears that CB86, CB204, and maybe other TSPO ligands are able to slow the progression of neurodegenerative diseases like PD. Abstract Parkinson’s disease (PD) is a progressive neurodegenerative disorder which is characterized by the degeneration of dopaminergic neurons in substantia nigra (SN). Oxidative stress or reactive oxygen species (ROS) generation was suggested to play a role in this specific type of neurodegeneration. Therapeutic options which can target and counteract ROS generation may be of benefit. TSPO ligands are known to counteract with neuro-inflammation, ROS generation, apoptosis, and necrosis. In the current study, we investigated an in vitro cellular PD model by the assessment of 6-hydroxydopamine (6-OHDA, 80 µM)-induced PC12 neurotoxicity. Simultaneously to the exposure of the cells to 6-OHDA, we added the TSPO ligands CB86 and CB204 (25 µM each) and assessed the impact on several markers of cell death. The two ligands normalized significantly (57% and 52% respectively, from 44%; whereas the control was 68%) cell proliferation at different time points from 0–24 h. Additionally, we evaluated the effect of these two TSPO ligands on necrosis using propidium iodide (PI) staining and found that the ligands inhibited significantly the 6-OHDA-induced necrosis. As compared to control, the red count was increased up to 57-fold whereas CB86 and CB204 inhibited to 2.7-fold and 3.2-fold respectively. Necrosis was also analyzed by LDH assay which showed significant effect. Both assays demonstrated similar potent anti-necrotic effect of the two TSPO ligands. Reactive oxygen species (ROS) generation induced by 6-OHDA was also inhibited by the two TSPO ligand up to 1.3 and 1.5-fold respectively, as compared to 6-OHDA group. CB86 and CB204 inhibited also normalized the cell viability up to 1.8-fold after the exposure to 6-OHDA, as assessed by XTT assay. The two TSPO ligands also inhibited apoptosis significantly (1.3-fold for both) as assessed by apopxin green staining. In summary, it appears that the two TSPO ligands CB86 and CB204 can suppress cell death of PC12 induced by 6-OHDA. The results may be relevant to the use of these two TSPO ligands as therapeutic option neurodegenerative diseases like PD.
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Boyd A, Byrne S, Middleton RJ, Banati RB, Liu GJ. Control of Neuroinflammation through Radiation-Induced Microglial Changes. Cells 2021; 10:2381. [PMID: 34572030 PMCID: PMC8468704 DOI: 10.3390/cells10092381] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/02/2021] [Accepted: 09/02/2021] [Indexed: 12/15/2022] Open
Abstract
Microglia, the innate immune cells of the central nervous system, play a pivotal role in the modulation of neuroinflammation. Neuroinflammation has been implicated in many diseases of the CNS, including Alzheimer's disease and Parkinson's disease. It is well documented that microglial activation, initiated by a variety of stressors, can trigger a potentially destructive neuroinflammatory response via the release of pro-inflammatory molecules, and reactive oxygen and nitrogen species. However, the potential anti-inflammatory and neuroprotective effects that microglia are also thought to exhibit have been under-investigated. The application of ionising radiation at different doses and dose schedules may reveal novel methods for the control of microglial response to stressors, potentially highlighting avenues for treatment of neuroinflammation associated CNS disorders, such as Alzheimer's disease and Parkinson's disease. There remains a need to characterise the response of microglia to radiation, particularly low dose ionising radiation.
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Affiliation(s)
- Alexandra Boyd
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia; (A.B.); (S.B.); (R.J.M.); (R.B.B.)
| | - Sarah Byrne
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia; (A.B.); (S.B.); (R.J.M.); (R.B.B.)
| | - Ryan J. Middleton
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia; (A.B.); (S.B.); (R.J.M.); (R.B.B.)
| | - Richard B. Banati
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia; (A.B.); (S.B.); (R.J.M.); (R.B.B.)
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, Sydney, NSW 2050, Australia
| | - Guo-Jun Liu
- Australian Nuclear Science and Technology Organisation, Sydney, NSW 2234, Australia; (A.B.); (S.B.); (R.J.M.); (R.B.B.)
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, Sydney, NSW 2050, Australia
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Fei M, Li Z, Cao Y, Jiang C, Lin H, Chen Z. MicroRNA-182 improves spinal cord injury in mice by modulating apoptosis and the inflammatory response via IKKβ/NF-κB. J Transl Med 2021; 101:1238-1253. [PMID: 34059758 PMCID: PMC8367816 DOI: 10.1038/s41374-021-00606-5] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 01/14/2023] Open
Abstract
Spinal cord injury (SCI) is one common neurological condition which involves primary injury and secondary injury. Neuron inflammation and apoptosis after SCI is the most important pathological process of this disease. Here, we tried to explore the influence and mechanism of miRNAs on the neuron inflammatory response and apoptosis after SCI. First, by re-analysis of Gene Expression Omnibus dataset (accession GSE19890), miR-182 was selected for further study because of its suppressive effects on the inflammatory response in the various types of injuries. Functional experiments demonstrated that miR-182 overexpression promoted functional recovery, reduced histopathological changes, and alleviated spinal cord edema in mice. It was also observed that miR-182 overexpression reduced apoptosis and attenuated the inflammatory response in spinal cord tissue, as evidenced by the reduction of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β, and the induction of IL-10. Using a lipopolysaccharide (LPS)-induced SCI model in BV-2 cells, we found that miR-182 was downregulated in the BV-2 cells following LPS stimulation, and upregulation of miR-182 improved LPS-induced cell damage, as reflected by the inhibition of apoptosis and the inflammatory response. IκB kinase β (IKKβ), an upstream target of the NF-κB pathway, was directly targeted by miR-182 and miR-182 suppressed its translation. Further experiments revealed that overexpression of IKKβ reversed the anti-apoptosis and anti-inflammatory effects of miR-182 in LPS stimulated BV-2 cells. Finally, we found that miR-182 overexpression blocked the activation of the NF-κB signaling pathway in vitro and in vivo, as demonstrated by the downregulation of phosphorylated (p‑) IκB-α and nuclear p-p65. Taken together, these data indicate that miR-182 improved SCI-induced secondary injury through inhibiting apoptosis and the inflammatory response by blocking the IKKβ/NF-κB pathway. Our findings suggest that upregulation of miR-182 may be a novel therapeutic target for SCI.
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Affiliation(s)
- Min Fei
- Department of Anesthesiology, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zheng Li
- Department of Orthopedics, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yuanwu Cao
- Department of Orthopedics, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Chang Jiang
- Department of Orthopedics, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Haodong Lin
- Department of Orthopedic Surgery, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
| | - Zixian Chen
- Department of Orthopedics, Zhongshan Hospital, Fudan University, Shanghai, China.
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Réus GZ, Giridharan VV, de Moura AB, Borba LA, Botelho MEM, Behenck JP, Generoso JS, Selvaraj S, Bhatti G, Barichello T, Quevedo J. The impact of early life stress and immune challenge on behavior and glia cells alteration in late adolescent rats. Int J Dev Neurosci 2021; 81:407-415. [PMID: 33788296 DOI: 10.1002/jdn.10108] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/08/2021] [Accepted: 03/25/2021] [Indexed: 01/06/2023] Open
Abstract
Maternal deprivation (MD) is known to be related to long-term changes that could influence the onset of psychiatric disorders. Studies have demonstrated that early life stress makes the cells in the brain more susceptible to subsequent stressors. To test it, we used an animal model of MD conducted from postnatal day (PND) 1 to 10. Deprived and non-deprived rats (control) were randomized to receive or not lipopolysaccharide (LPS) at 5 mg/kg on PND 50. The behavior and glial cells activation were evaluated in all groups from 51 to 53 PND. There was an increase in the immobility time in the MD and MD+LPS groups. The spontaneous locomotor activity was not changed between groups. We found elevated ionized calcium-binding adapter molecule 1 (Iba-1)-positive cells levels in the control+LPS and MD+LPS groups. In the MD+LPS group, it was found an increase in Iba-positive cells compared to the MD+sal group. The glial fibrillary acidic protein (GFAP)-positive cells were also increased in the MD+LPS, compared to control+sal, control+LPS, and MD+sal groups. Immune challenge by LPS in late adolescence, which was subjected to MD, did not influence the depressive-like behavior but exerted a pronounced effect in the microglial activation and astrocyte atrophy.
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Affiliation(s)
- Gislaine Z Réus
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Vijayasree V Giridharan
- Translational Psychiatry Program, Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
| | - Airam B de Moura
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Laura A Borba
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Maria Eduarda M Botelho
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - João Paulo Behenck
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Jaqueline S Generoso
- Laboratory of Experimental Microbiology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - Sudhakar Selvaraj
- Louis Faillace, MD, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Gursimrat Bhatti
- Translational Psychiatry Program, Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
| | - Tatiana Barichello
- Translational Psychiatry Program, Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
- Laboratory of Experimental Microbiology, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
| | - João Quevedo
- Translational Psychiatry Laboratory, Graduate Program in Health Sciences, University of Southern Santa Catarina (UNESC), Criciúma, Brazil
- Translational Psychiatry Program, Faillace Department of Psychiatry and Behavioral Sciences, McGovern Medical School, University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
- Center of Excellence on Mood Disorders, Department of Psychiatry and Behavioral Sciences, McGovern Medical School, The University of Texas Health Science Center at Houston (UTHealth), Houston, TX, USA
- Neuroscience Graduate Program, The University of Texas Graduate School of Biomedical Sciences at Houston, Houston, TX, USA
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Naloxone Protects against Lipopolysaccharide-Induced Neuroinflammation and Microglial Activation via Inhibiting ATP-Sensitive Potassium Channel. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2021; 2021:7731528. [PMID: 34373698 PMCID: PMC8349287 DOI: 10.1155/2021/7731528] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 06/27/2021] [Accepted: 07/12/2021] [Indexed: 01/10/2023]
Abstract
Aim The aim of this study was to evaluate the anti-inflammatory effects and underlying mechanism of naloxone on lipopolysaccharide- (LPS-) induced neuronal inflammation and microglial activation. Methods LPS-treated microglial BV-2 cells and mice were used to investigate the anti-inflammatory effects of naloxone. Results The results showed that naloxone dose-dependently promoted cell proliferation in LPS-induced BV-2 cells, downregulated the expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and proinflammatory enzymes iNOS and COX-2 as well as the expression of free radical molecule NO, and reduced the expression of Iba-1-positive microglia in LPS-stimulated BV-2 cells and mouse brain. Moreover, naloxone improved LPS-induced behavior degeneration in mice. Mechanically, naloxone inhibited LPS-induced activation in the ATP-sensitive potassium (KATP) channel. However, the presence of glibenclamide (Glib), an antagonist of KATP channel, ameliorated the suppressive effects of naloxone on inflammation and microglial activation. Conclusion Naloxone prevented LPS-induced neuroinflammation and microglial activation partially through the KATP channel. These findings might highlight the potential of naloxone in neuroinflammation therapy.
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MicroRNA-129-5p alleviates spinal cord injury in mice via suppressing the apoptosis and inflammatory response through HMGB1/TLR4/NF-κB pathway. Biosci Rep 2021; 40:222205. [PMID: 32096822 PMCID: PMC7069919 DOI: 10.1042/bsr20193315] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 02/15/2020] [Accepted: 02/17/2020] [Indexed: 12/15/2022] Open
Abstract
Secondary injury after spinal cord injury (SCI) is one reversible pathological change mainly involving excessive inflammatory response and neuro-apoptosis. Since in recent years, microRNAs (miRNAs) have been proposed as novel regulators of inflammation in different disease conditions. However, the role of miRNAs in the inflammatory response and apoptosis of secondary injury after SCI remains to be fully elucidated. Here, we tried to explore the influence and mechanism of miRNAs on the neuron inflammatory response and apoptosis after SCI. The expression profiles of miRNA were examined using miRNA microarray, and among the candidate miRNAs, miR-129-5p was found to be the most down-regulated miRNA in spinal tissues. Overexpression of miR-129-5p using agomir-miR-129-5p promoted injury mice functional recovery, suppressed the apoptosis and alleviated inflammatory response in spinal tissues. Using LPS-induced BV-2 cell model, we found miR-129-5p was also proved in protecting inflammatory response and cell apoptosis in vitro. High-mobility group protein B1 (HMGB1), a well-known inflammatory mediator, was found to be directly targeted by miR-129-5p and it was associated with the inhibitory effect of miR-129-5p on the activation of toll-like receptor (TLR)-4 (TLR4)/ nuclear factor-κB (NF-κB) pathway in vitro and in vivo. Further experiments revealed that the anti-apoptosis and anti-inflammatory effects of miR-129-5p were reversed by HMGB1 overexpression in BV-2 cells. Collectively, these data revealed that miR-129-5p alleviated SCI in mice via suppressing the apoptosis and inflammatory response through HMGB1//TLR4/NF-κB pathway. Our data suggest that up-regulation of miR-129-5p may be a novel therapeutic target for SCI.
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De novo Neurosteroidogenesis in Human Microglia: Involvement of the 18 kDa Translocator Protein. Int J Mol Sci 2021; 22:ijms22063115. [PMID: 33803741 PMCID: PMC8003294 DOI: 10.3390/ijms22063115] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/06/2021] [Accepted: 03/15/2021] [Indexed: 12/14/2022] Open
Abstract
Neuroactive steroids are potent modulators of microglial functions and are capable of counteracting their excessive reactivity. This action has mainly been ascribed to neuroactive steroids released from other sources, as microglia have been defined unable to produce neurosteroids de novo. Unexpectedly, immortalized murine microglia recently exhibited this de novo biosynthesis; herein, de novo neurosteroidogenesis was characterized in immortalized human microglia. The results demonstrated that C20 and HMC3 microglial cells constitutively express members of the neurosteroidogenesis multiprotein machinery-in particular, the transduceosome members StAR and TSPO, and the enzyme CYP11A1. Moreover, both cell lines produce pregnenolone and transcriptionally express the enzymes involved in neurosteroidogenesis. The high TSPO expression levels observed in microglia prompted us to assess its role in de novo neurosteroidogenesis. TSPO siRNA and TSPO synthetic ligand treatments were used to reduce and prompt TSPO function, respectively. The TSPO expression downregulation compromised the de novo neurosteroidogenesis and led to an increase in StAR expression, probably as a compensatory mechanism. The pharmacological TSPO stimulation the de novo neurosteroidogenesis improved in turn the neurosteroid-mediated release of Brain-Derived Neurotrophic Factor. In conclusion, these results demonstrated that de novo neurosteroidogenesis occurs in human microglia, unravelling a new mechanism potentially useful for future therapeutic purposes.
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Chang CW, Chiu CH, Lin MH, Wu HM, Yu TH, Wang PY, Kuo YY, Huang YY, Shiue CY, Huang WS, Yeh SHH. GMP-compliant fully automated radiosynthesis of [ 18F]FEPPA for PET/MRI imaging of regional brain TSPO expression. EJNMMI Res 2021; 11:26. [PMID: 33725191 PMCID: PMC7966678 DOI: 10.1186/s13550-021-00768-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 03/03/2021] [Indexed: 12/02/2022] Open
Abstract
Background Expression of translocator protein (TSPO) on the outer mitochondrial membrane of activated microglia is strongly associated with neuroinflammation. The second-generation PET ligand [18F]FEPPA specifically binds TSPO to enable in vivo visualization and quantification of neuroinflammation. We optimized a fully automated radiosynthesis method and evaluated the utility of [18F]FEPPA, the second-generation PET ligand specifically binds TSPO, in a mouse model of systemic LPS challenge to detect TSPO-associated signals of central and peripheral inflammation. In vivo dynamic PET/MR imaging was performed in LPS-induced and control mice after [18F]FEPPA administration. The relationship between the [18F]FEPPA signal and the dose of LPS was assessed. The cytokine levels (i.e., TNF-α, Il-1β, Il-6) in LPS-induced mice were measured by RT-PCR. Standard uptake value (SUV), total volume of distribution (VT) and area under the curve (AUC) were determined based on the metabolite-uncorrected plasma input function. Western blotting and immunostaining were used to measure TSPO expression in the brain. Results The fully automated [18F]FEPPA radiosynthesis produced an uncorrected radiochemical yield of 30 ± 2% within 80 min, with a radiochemical purity greater than 99% and specific activity of 148.9‒216.8 GBq/µmol. Significant differences were observed in the brain after [18F]FEPPA administration: SUV, VT and AUC were 1.61 ± 0.1, 1.25 ± 0.12 and 1.58 ± 0.09-fold higher in LPS-injected mice than controls. TNF-α, Il-1β and Il-6 mRNA levels were also elevated in the brains of LPS-injected mice. Western blotting revealed TSPO (p < 0.05) and Iba-1 (p < 0.01) were upregulated in the brain after LPS administration. In LPS-injected mice, TSPO immunoactivity colocalized with Iba-1 in the cerebrum and TSPO was significantly overexpressed in the hippocampus and cerebellum. The peripheral organs (heart, lung) of LPS-injected mice had higher [18F]FEPPA signal-to-noise ratios than control mice. Conclusions Based on the current data on ligand specificity and selectivity in central tissues using 7 T PET/MR imaging, we demonstrate that [18F]FEPPA accumulations significant increased in the specific brain regions of systemic LPS-induced neuroinflammation (5 mg/kg). Future investigations are needed to determine the sensitivity of [18F]FEPPA as a biomarker of neuroinflammation as well as the correlation between the PET signal intensity and the expression levels of TSPO. Supplementary Information The online version contains supplementary material available at 10.1186/s13550-021-00768-9.
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Affiliation(s)
- Chi-Wei Chang
- Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Medical Imaging and Radiological Technology, The Institute of Radiological Sciences, Tzu Chi University of Science and Technology, Hualien City, Taiwan.,Department of Biomedical Engineering and Environmental Sciences, National Tsinghua University, Hsinchu, Taiwan
| | - Chuang-Hsin Chiu
- Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan
| | - Ming-Hsien Lin
- Department of Nuclear Medicine, Cheng Hsin General Hospital, Taipei, Taiwan.,Department of Nuclear Medicine, Camillian Saint Mary's Hospital Luodong, Yilan, Taiwan
| | - Hung-Ming Wu
- Department of Neurology, Changhua Christian Hospital, Changhua, Taiwan
| | - Tsung-Hsun Yu
- Brain Research Center, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong Street, Taipei, 112, Taiwan
| | - Pao-Yeh Wang
- Brain Research Center, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong Street, Taipei, 112, Taiwan
| | - Yu-Yeh Kuo
- Brain Research Center, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong Street, Taipei, 112, Taiwan
| | - Ya-Yao Huang
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, 100, Taiwan.,Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Chyng-Yann Shiue
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan.,PET Center, Department of Nuclear Medicine, Tri-Service General Hospital, Taipei, Taiwan
| | - Wen-Sheng Huang
- Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.,Department of Nuclear Medicine, Taipei Medical University Hospital, Taipei, Taiwan
| | - Skye Hsin-Hsien Yeh
- Brain Research Center, National Yang Ming Chiao Tung University, No. 155, Sec. 2, Linong Street, Taipei, 112, Taiwan.
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Monga S, Weizman A, Gavish M. The Efficacy of the Novel TSPO Ligands 2-Cl-MGV-1 and 2,4-Di-Cl-MGV-1 Compared to the Classical TSPO Ligand PK 11195 to Counteract the Release of Chemokines from LPS-Stimulated BV-2 Microglial Cells. BIOLOGY 2020; 9:E291. [PMID: 32938018 PMCID: PMC7565396 DOI: 10.3390/biology9090291] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/08/2020] [Accepted: 09/10/2020] [Indexed: 12/15/2022]
Abstract
The impact of ligands of the 18 kDa translocator protein (TSPO) on the release of chemokines is not vastly investigated. In the present study, we assessed the effect of our novel TSPO ligands 2-Cl-MGV-1 and 2,4-Di-Cl-MGV-1 compared to the classical TSPO ligand PK 11195 on chemokine release in LPS-stimulated BV-2 microglial cells. As per the effect of 2-Cl-MGV-1, CCL2, CCL3, and CCL5 were inhibited by 90%, CCL8 by 97%, and IL-2 by 77% (p < 0.05 for all). 2,4-Di-Cl-MGV-1 inhibited CCL2 release by 92%, CCL3 by 91%, CCL5 by 90%, CCL8 by 89%, and IL-2 by 80% (p < 0.05 for all). PK 11195 exhibited weaker inhibitory effects: CCL2 by 22%, CCL3 by 83%, CCL5 by 34%, CCL8 by 41%, and the cytokine IL-2 by 14% (p < 0.05 for all). Thus, it appears that the novel TSPO ligands are potent suppressors of LPS-stimulated BV-2 microglial cells, and their inhibitory effect is larger than that of PK 11195. Such immunomodulatory effects on microglial cells may be relevant to the treatment of neurodegenerative and neuroinflammatory diseases.
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Affiliation(s)
- Sheelu Monga
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel;
| | - Abraham Weizman
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel;
- Research Unit, Geha Mental Health Center and Felsenstein Medical Research Center, Petah Tikva 4910002, Israel
| | - Moshe Gavish
- Ruth and Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel;
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IRF5 Signaling in Phagocytes Is Detrimental to Neonatal Hypoxic Ischemic Encephalopathy. Transl Stroke Res 2020; 12:602-614. [PMID: 32761315 DOI: 10.1007/s12975-020-00832-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 06/10/2020] [Accepted: 07/01/2020] [Indexed: 01/20/2023]
Abstract
Immune responses to neonatal hypoxic ischemic encephalopathy (HIE) exacerbate brain injury. Phagocytes, including microglia, play a central role in the immune response, but how the activation of phagocytes is regulated remains elusive. Previously, we have reported that interferon regulatory factor 5 (IRF5) signaling is closely correlated with a pro-inflammatory microglial phenotype in adult mice after stroke. The present study investigated IRF5's regulatory role in post-HIE inflammation. Male IRF5 conditional knockout (CKO) and IRF5fl/fl postnatal day 10 (P10) pups were subjected to the Rice-Vannucci model (RVM) to induce HIE. Outcomes including morphological and neurobehavioral changes were evaluated at day 7 after HIE. Microglia/macrophage phenotypes and inflammatory responses were evaluated by flow cytometry (FC), RT-PCR, and multiplex cytokine assays. Lenti-IRF5 virus was administered in microglia-neuron co-cultures to evaluate the effects of microglial IRF5 upregulation in ischemic neurons exposed to oxygen-glucose deprivation (OGD). Deletion of phagocytic IRF5 resulted in significantly decreased IRF5 expression, attenuated pro-inflammatory and enhanced anti-inflammatory responses to HIE, and improved outcomes compared with IRF5fl/fl control pups. In vitro lentivirus transfection experiments revealed that overexpression of IRF5 in microglia amplified pro-inflammatory signals and exacerbated OGD-induced neuronal apoptosis and neurite fragmentation. IRF5 signaling mediates microglial pro-inflammatory activation and also affects anti-inflammatory responses. Phagocytic IRF5 signaling is detrimental in HIE and is a potential therapeutic target for post-ischemic inflammation.
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Abstract
Alzheimer’s disease (AD) is a multifactorial neurodegenerative disease and has become a major socioeconomic issue in many developed countries. Currently available therapeutic agents for AD provide only symptomatic treatments, mainly because the complete mechanism of the AD pathogenesis is still unclear. Although several different hypotheses have been proposed, mitochondrial dysfunction has gathered interest because of its profound effect on brain bioenergetics and neuronal survival in the pathophysiology of AD. Various therapeutic agents targeting the mitochondrial pathways associated with AD have been developed over the past decade. Although most of these agents are still early in the clinical development process, they are used to restore mitochondrial function, which provides an alternative therapeutic strategy that is likely to slow the progression of the disease. In this mini review, we will survey the AD-related mitochondrial pathways and their small-molecule modulators that have therapeutic potential. We will focus on recently reported examples, and also overview the current challenges and future perspectives of ongoing research.
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Affiliation(s)
- Ji Woong Lim
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Jiyoun Lee
- Department of Global Medical Science, Sungshin University, Seoul 01133, Korea
| | - Ae Nim Pae
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology, Seoul 02792; Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Korea
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21
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18-kDa translocator protein association complexes in the brain: From structure to function. Biochem Pharmacol 2020; 177:114015. [PMID: 32387458 DOI: 10.1016/j.bcp.2020.114015] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/04/2020] [Indexed: 12/14/2022]
Abstract
The outer mitochondrial membrane 18-kDa translocator protein (TSPO) is highly conserved in organisms of different species and ubiquitously expressed throughout tissues, including the nervous system. In the healthy adult brain, TSPO expression levels are low and promptly modulated under different pathological conditions, such as cancer, inflammatory states, and neurological and psychiatric disorders. Not surprisingly, several endogenous and synthetic molecules capable of binding TSPO have been proposed as drugs or diagnostic tools for brain diseases. The most studied biochemical function of TSPO is cholesterol translocation into mitochondria, which in turn affects the synthesis of steroids in the periphery and neurosteroids in the brain. In the last 30 years, roles for TSPO have also been suggested in other cellular processes, such as heme synthesis, apoptosis, autophagy, calcium signalling and reactive oxygen species production. Herein, we provide an overview of TSPO associations with different proteins, focusing particular attention on their related functions. Furthermore, recent TSPO-targeted therapeutic interventions are explored and discussed as prospect for innovative treatments in mental and brain diseases.
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22
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Monga S, Denora N, Laquintana V, Franco M, Marek I, Singh S, Nagler R, Weizman A, Gavish M. The protective effect of the TSPO ligands 2,4-Di-Cl-MGV-1, CB86, and CB204 against LPS-induced M1 pro-inflammatory activation of microglia. Brain Behav Immun Health 2020; 5:100083. [PMID: 34589858 PMCID: PMC8474401 DOI: 10.1016/j.bbih.2020.100083] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 05/14/2020] [Accepted: 05/16/2020] [Indexed: 01/20/2023] Open
Abstract
We have shown previously, that the 18 kDa translocator protein (TSPO) synthetic ligands quinazoline derivatives (2-Cl-MGV-1 and MGV-1) can inhibit activation of in BV-2 microglial cells. In the present study we assessed the impact of novel TSPO ligands on lipopolysaccharide (LPS)-induced microglial activation as expressed by release of pro-inflammatory molecules, including cytokines [interleukin-6 (IL-6), IL-1β, interferon- γ (IFN-γ)] nitric oxide (NO), CD8, and cyclo-oxygenase-2 (COX-2). The TSPO ligands 2,4-Di-Cl-MGV-1, CB86, and CB204 counteracted with the LPS-induced microglial activation. Exposure to LPS along with the TSPO ligand 2,4-Di-Cl-MGV-1 (25 μM) reduced significantly the release of NO by 24-, IL-6 by 14-, IL-β by 14-, IFN- γ by 6-, and TNF-α by 29-folds, respectively. In contrast to the anti-neuroinflammatory effect of the TSPO ligands, the effect of diclofenac sodium (DS; 25 μM) did not reach statistical significance. No alterations in IL-10 and IL-13 were detected (M2 anti-inflammatory pathway) during the inhibition of M1 pro-inflammatory pathway.
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Affiliation(s)
- Sheelu Monga
- Technion- Israel Institute of Technology, Ruth and Bruce Rappaport Faculty of Medicine, Israel
| | - Nunzio Denora
- Dipartimento di Farmacia – Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Italy
| | - Valentino Laquintana
- Dipartimento di Farmacia – Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Italy
| | - Massimo Franco
- Dipartimento di Farmacia – Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Italy
| | - Ilan Marek
- Technion- Israel Institute of Technology, Schulich Faculty of Chemistry, Israel
| | - Sukhdev Singh
- Technion- Israel Institute of Technology, Schulich Faculty of Chemistry, Israel
| | - Rafi Nagler
- Technion- Israel Institute of Technology, Ruth and Bruce Rappaport Faculty of Medicine, Israel
| | - Abraham Weizman
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Research Unit, Geha Mental Health Center and Felsenstein Medical Research Center, Petah Tikva, Israel
| | - Moshe Gavish
- Technion- Israel Institute of Technology, Ruth and Bruce Rappaport Faculty of Medicine, Israel
- Corresponding author.
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23
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Dimitrova-Shumkovska J, Krstanoski L, Veenman L. Diagnostic and Therapeutic Potential of TSPO Studies Regarding Neurodegenerative Diseases, Psychiatric Disorders, Alcohol Use Disorders, Traumatic Brain Injury, and Stroke: An Update. Cells 2020; 9:cells9040870. [PMID: 32252470 PMCID: PMC7226777 DOI: 10.3390/cells9040870] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 03/29/2020] [Accepted: 03/30/2020] [Indexed: 02/08/2023] Open
Abstract
Neuroinflammation and cell death are among the common symptoms of many central nervous system diseases and injuries. Neuroinflammation and programmed cell death of the various cell types in the brain appear to be part of these disorders, and characteristic for each cell type, including neurons and glia cells. Concerning the effects of 18-kDa translocator protein (TSPO) on glial activation, as well as being associated with neuronal cell death, as a response mechanism to oxidative stress, the changes of its expression assayed with the aid of TSPO-specific positron emission tomography (PET) tracers' uptake could also offer evidence for following the pathogenesis of these disorders. This could potentially increase the number of diagnostic tests to accurately establish the stadium and development of the disease in question. Nonetheless, the differences in results regarding TSPO PET signals of first and second generations of tracers measured in patients with neurological disorders versus healthy controls indicate that we still have to understand more regarding TSPO characteristics. Expanding on investigations regarding the neuroprotective and healing effects of TSPO ligands could also contribute to a better understanding of the therapeutic potential of TSPO activity for brain damage due to brain injury and disease. Studies so far have directed attention to the effects on neurons and glia, and processes, such as death, inflammation, and regeneration. It is definitely worthwhile to drive such studies forward. From recent research it also appears that TSPO ligands, such as PK11195, Etifoxine, Emapunil, and 2-Cl-MGV-1, demonstrate the potential of targeting TSPO for treatments of brain diseases and disorders.
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Affiliation(s)
- Jasmina Dimitrova-Shumkovska
- Department of Experimental Biochemistry, Institute of Biology, Faculty of Natural Sciences and Mathematics, University Ss Cyril and Methodius, Arhimedova 3, P.O. Box 162, 1000 Skopje, Republic of North Macedonia;
- Correspondence: (J.D.-S.); (L.V.)
| | - Ljupcho Krstanoski
- Department of Experimental Biochemistry, Institute of Biology, Faculty of Natural Sciences and Mathematics, University Ss Cyril and Methodius, Arhimedova 3, P.O. Box 162, 1000 Skopje, Republic of North Macedonia;
| | - Leo Veenman
- Technion-Israel Institute of Technology, Faculty of Medicine, Rappaport Institute of Medical Research, 1 Efron Street, P.O. Box 9697, Haifa 31096, Israel
- Correspondence: (J.D.-S.); (L.V.)
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24
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Nagler R, Zeineh N, Azrad M, Yassin N, Weizman A, Gavish M. 18-kDa Translocator Protein Ligands Protect H9C2 Cardiomyocytes from Cigarette Smoke-induced Cell Death: In Vitro Study. In Vivo 2020; 34:549-556. [PMID: 32111753 PMCID: PMC7157870 DOI: 10.21873/invivo.11807] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 12/30/2019] [Accepted: 01/02/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Cigarette smoke (CS) can induce cellular damage via alterations in 18 kDa translocator protein (TSPO)-related functions, leading to cardiovascular diseases. The current study focused on the possible protective effect of TSPO ligands against CS-induced damage to cardiac cells. MATERIALS AND METHODS H9C2 Cardiomyocyte cell line of rat origin was pre-treated with TSPO ligands. Cell death, TSPO binding, and TSPO protein expression levels were assessed following 30-min CS exposure with/without TSPO ligands. RESULTS CS exposure of H9C2 cells significantly incensed cell death (by 26%, p<0.001). Pre-treatment with TSPO ligands at two concentrations prevented cell death. Neither CS nor ligands affected TSPO protein expression in H9C2 cells. CS led to increased cell death and reduced TSPO binding. CONCLUSION Reduced TSPO binding may have a role in CS-induced cell death, and TSPO ligand MGV-1 can prevent suppression of TSPO binding and corresponding cell death. These results may be relevant to treatment of cardiovascular diseases associated with CS.
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Affiliation(s)
- Rafael Nagler
- Department of Neuroscience, Faculty of Medicine, Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Nidal Zeineh
- Department of Neuroscience, Faculty of Medicine, Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Maya Azrad
- Department of Neuroscience, Faculty of Medicine, Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Nasra Yassin
- Department of Neuroscience, Faculty of Medicine, Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
| | - Abraham Weizman
- Research Unit at Geha Mental Health Center and Laboratory of Biological Psychiatry at Felsenstein Medical Research Center, Petah Tikva, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moshe Gavish
- Department of Neuroscience, Faculty of Medicine, Rappaport Family Institute for Research in the Medical Sciences, Technion - Israel Institute of Technology, Haifa, Israel
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25
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Betlazar C, Middleton RJ, Banati R, Liu GJ. The Translocator Protein (TSPO) in Mitochondrial Bioenergetics and Immune Processes. Cells 2020; 9:cells9020512. [PMID: 32102369 PMCID: PMC7072813 DOI: 10.3390/cells9020512] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/19/2020] [Accepted: 02/19/2020] [Indexed: 12/11/2022] Open
Abstract
The translocator protein (TSPO) is an outer mitochondrial membrane protein that is widely used as a biomarker of neuroinflammation, being markedly upregulated in activated microglia in a range of brain pathologies. Despite its extensive use as a target in molecular imaging studies, the exact cellular functions of this protein remain in question. The long-held view that TSPO plays a fundamental role in the translocation of cholesterol through the mitochondrial membranes, and thus, steroidogenesis, has been disputed by several groups with the advent of TSPO knockout mouse models. Instead, much evidence is emerging that TSPO plays a fundamental role in cellular bioenergetics and associated mitochondrial functions, also part of a greater role in the innate immune processes of microglia. In this review, we examine the more direct experimental literature surrounding the immunomodulatory effects of TSPO. We also review studies which highlight a more central role for TSPO in mitochondrial processes, from energy metabolism, to the propagation of inflammatory responses through reactive oxygen species (ROS) modulation. In this way, we highlight a paradigm shift in approaches to TSPO functioning.
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Affiliation(s)
- Calina Betlazar
- Human Health, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia; (R.J.M.); (R.B.)
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia
- Correspondence: (C.B.); (G-J.L.)
| | - Ryan J. Middleton
- Human Health, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia; (R.J.M.); (R.B.)
| | - Richard Banati
- Human Health, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia; (R.J.M.); (R.B.)
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia
| | - Guo-Jun Liu
- Human Health, Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights, NSW 2234, Australia; (R.J.M.); (R.B.)
- Discipline of Medical Imaging & Radiation Sciences, Faculty of Medicine and Health, Brain and Mind Centre, University of Sydney, 94 Mallett Street, Camperdown, NSW 2050, Australia
- Correspondence: (C.B.); (G-J.L.)
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Lim JW, Lee J, Pae AN. Mitochondrial dysfunction and Alzheimer's disease: prospects for therapeutic intervention. BMB Rep 2020; 53:47-55. [PMID: 31818365 PMCID: PMC6999825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Indexed: 03/29/2024] Open
Abstract
Alzheimer's disease (AD) is a multifactorial neurodegenerative disease and has become a major socioeconomic issue in many developed countries. Currently available therapeutic agents for AD provide only symptomatic treatments, mainly because the complete mechanism of the AD pathogenesis is still unclear. Although several different hypotheses have been proposed, mitochondrial dysfunction has gathered interest because of its profound effect on brain bioenergetics and neuronal survival in the pathophysiology of AD. Various therapeutic agents targeting the mitochondrial pathways associated with AD have been developed over the past decade. Although most of these agents are still early in the clinical development process, they are used to restore mitochondrial function, which provides an alternative therapeutic strategy that is likely to slow the progression of the disease. In this mini review, we will survey the AD-related mitochondrial pathways and their small-molecule modulators that have therapeutic potential. We will focus on recently reported examples, and also overview the current challenges and future perspectives of ongoing research. [BMB Reports 2020; 53(1): 47-55].
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Affiliation(s)
- Ji Woong Lim
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology, Seoul 02792,
Korea
| | - Jiyoun Lee
- Department of Global Medical Science, Sungshin University, Seoul 01133,
Korea
| | - Ae Nim Pae
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology, Seoul 02792,
Korea
- Division of Bio-Medical Science & Technology, KIST School, Korea University of Science and Technology, Seoul 02792,
Korea
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Microglial IRF5-IRF4 regulatory axis regulates neuroinflammation after cerebral ischemia and impacts stroke outcomes. Proc Natl Acad Sci U S A 2019; 117:1742-1752. [PMID: 31892541 DOI: 10.1073/pnas.1914742117] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Microglial activation plays a central role in poststroke inflammation and causes secondary neuronal damage; however, it also contributes in debris clearance and chronic recovery. Microglial pro- and antiinflammatory responses (or so-called M1-M2 phenotypes) coexist and antagonize each other throughout the disease progress. As a result of this balance, poststroke immune responses alter stroke outcomes. Our previous study found microglial expression of interferon regulatory factor 5 (IRF5) and IRF4 was related to pro- and antiinflammatory responses, respectively. In the present study, we genetically modified the IRF5 and IRF4 signaling to explore their roles in stroke. Both in vitro and in vivo assays were utilized; IRF5 or IRF4 small interfering RNA (siRNA), lentivirus, and conditional knockout (CKO) techniques were employed to modulate IRF5 or IRF4 expression in microglia. We used a transient middle cerebral artery occlusion model to induce stroke and examined both acute and chronic stroke outcomes. Poststroke inflammation was evaluated with flow cytometry, RT-PCR, MultiPlex, and immunofluorescence staining. An oscillating pattern of the IRF5-IRF4 regulatory axis function was revealed. Down-regulation of IRF5 signaling by siRNA or CKO resulted in increased IRF4 expression, enhanced M2 activation, quenched proinflammatory responses, and improved stroke outcomes, whereas down-regulation of IRF4 led to increased IRF5 expression, enhanced M1 activation, exacerbated proinflammatory responses, and worse functional recovery. Up-regulation of IRF4 or IRF5 by lentivirus induced similar results. We conclude that the IRF5-IRF4 regulatory axis is a key determinant in microglial activation. The IRF5-IRF4 regulatory axis is a potential therapeutic target for neuroinflammation and ischemic stroke.
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