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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; 224:80-90. [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] [MESH Headings] [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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2
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Dong L, Gao L. JMJD3 and SNAI2 synergistically protect against Parkinson's disease by mediating the YAP/HIF1α signaling pathway in a mouse model. Hum Mol Genet 2023; 32:3040-3052. [PMID: 37453035 DOI: 10.1093/hmg/ddad115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 07/07/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023] Open
Abstract
This study aimed to characterize the functional relevance and mechanistic basis of the histone demethylase Jumonji domain-containing protein-3 (JMJD3) in preserving dopaminergic neuron survival in Parkinson's disease (PD). Mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced lesions and MN9D dopaminergic neuronal cell lines exposed to 6-OHDA, respectively, were used to simulate in vivo and in vitro PD-like environments. PD-related genes with differential expressions were identified using RNA sequencing of hippocampal tissues collected from MPTP-lesioned mice. A specific lentiviral shRNA vector was used to investigate the effects of JMJD3 on neuron activities in vitro and PD-like phenotypes in vivo. JMJD3 was found to up-regulate the expression of Snail family transcriptional repressor 2 (SNAI2) through the inhibition of H3 on lysine 27 (H3K27me3) enrichment in the SNAI2 promoter region. As a result, the viability of 6-OHDA-exposed MN9D cells was stimulated, and cell apoptosis was diminished. Knockdown of SNAI2 decreased the expression of yes-associated protein (YAP) and HIF1α while also reducing the viability of 6-OHDA-exposed MN9D cells and increasing cell apoptosis. The in vivo experiments demonstrated that JMJD3 activated the SNAI2/YAP/HIF1α signaling pathway, inhibiting PD-like phenotypes in MPTP-lesioned mice. Thus, the findings provide evidence that JMJD3 inhibits the enrichment of H3K27me3 at the SNAI2 promoter, leading to the upregulation of SNAI2 expression and activation of the YAP/HIF1α signaling pathway, ultimately exerting a protective effect on PD mice. This finding suggests that targeting the JMJD3-SNAI2 pathway could be a promising therapeutic strategy for PD. Further in-depth studies are needed to elucidate the underlying mechanisms and identify potential downstream targets of this pathway.
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Affiliation(s)
- Li Dong
- Department of Neurology, The Fourth Affiliated Hospital of China Medical University, Shenyang 110032, China
| | - Lianbo Gao
- Department of Neurology, The Fourth Affiliated Hospital of China Medical University, Shenyang 110032, China
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3
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Miura S, Oyanagi E, Watanabe C, Hamada H, Aoki T, Kremenik MJ, Yano H. Acetyl-L-carnitine attenuates Poly I: C- induced sickness behavior in mice. Biosci Biotechnol Biochem 2022; 86:1423-1430. [PMID: 35945649 DOI: 10.1093/bbb/zbac132] [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: 05/06/2022] [Accepted: 07/27/2022] [Indexed: 11/14/2022]
Abstract
Fatigue is accompanied by a decrease in physical activity or malaise, and might be reduced by acetyl-L-carnitine (ALC) administration. The purpose of this study was to investigate the preventive effects of ALC on Poly I: C-induced sickness behavior in mice. For the experiment, male C3H/HeN mice were used and treated with ALC for 5 days before Poly I: C administration. ALC administration attenuated the decrease in wheel behavior activity of mice at 24 h after Poly I: C administration, and ALC treated mice quickly recovered from the sickness behavior. The gene expression of brain-derived neurotrophic factor (BDNF) in the cerebrum and hippocampus, which is associated with physical activity, was higher in the ALC-treated group. Translocator protein 18kDa (TSPO), which has cytoprotective effects, was up-regulated in the cerebrum and hippocampus, suggesting that ALC suppressed the decrease in activity induced by Poly I: C treatment through enhancement of cytoprotective effects in the brain.
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Affiliation(s)
- Suzuka Miura
- Department of Health and Sports Science, Kawasaki University of Medical Welfare, Kurashiki, Okayama, 288 Matsushima, Kurashiki, Okayama, Japan
| | - Eri Oyanagi
- Department of Health and Sports Science, Kawasaki University of Medical Welfare, Kurashiki, Okayama, 288 Matsushima, Kurashiki, Okayama, Japan
| | - Chihiro Watanabe
- Department of Health and Sports Science, Kawasaki University of Medical Welfare, Kurashiki, Okayama, 288 Matsushima, Kurashiki, Okayama, Japan
| | - Hiroki Hamada
- Department of Health and Sports Science, Kawasaki University of Medical Welfare, Kurashiki, Okayama, 288 Matsushima, Kurashiki, Okayama, Japan
| | - Takafumi Aoki
- Department of Clinical Nutrition, Kawasaki University of Medical Welfare, Kurashiki, 288 Matsushima, Kurashiki, Okayama, Japan
| | - Michael J Kremenik
- Department of Health and Sports Science, Kawasaki University of Medical Welfare, Kurashiki, Okayama, 288 Matsushima, Kurashiki, Okayama, Japan
| | - Hiromi Yano
- Department of Health and Sports Science, Kawasaki University of Medical Welfare, Kurashiki, Okayama, 288 Matsushima, Kurashiki, Okayama, Japan
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Iliopoulou SM, Tsartsalis S, Kaiser S, Millet P, Tournier BB. Dopamine and Neuroinflammation in Schizophrenia - Interpreting the Findings from Translocator Protein (18kDa) PET Imaging. Neuropsychiatr Dis Treat 2021; 17:3345-3357. [PMID: 34819729 PMCID: PMC8608287 DOI: 10.2147/ndt.s334027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 10/09/2021] [Indexed: 12/22/2022] Open
Abstract
Schizophrenia is a complex disease whose pathophysiology is not yet fully understood. In addition to the long prevailing dopaminergic hypothesis, the evidence suggests that neuroinflammation plays a role in the pathophysiology of the disease. Recent studies using positron emission tomography (PET) that target a 18kDa translocator protein (TSPO) in activated microglial cells in an attempt to measure neuroinflammation in patients have shown a decrease or a lack of an increase in TSPO binding. Many biological and methodological considerations have been formulated to explain these findings. Although dopamine has been described as an immunomodulatory molecule, its potential role in neuroinflammation has not been explored in the aforementioned studies. In this review, we discuss the interactions between dopamine and neuroinflammation in psychotic states. Dopamine may inhibit neuroinflammation in activated microglia. Proinflammatory molecules released from microglia may decrease dopaminergic transmission. This could potentially explain why the levels of neuroinflammation in the brain of patients with schizophrenia seem to be unchanged or decreased compared to those in healthy subjects. However, most data are indirect and are derived from animal studies or from studies performed outside the field of schizophrenia. Further studies are needed to combine TSPO and dopamine imaging to study the association between microglial activation and dopamine system function.
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Affiliation(s)
- Sotiria Maria Iliopoulou
- Adult Psychiatry Division, Department of Psychiatry, Geneva University Hospitals (HUG), Geneva, 1225, Switzerland
| | | | - Stefan Kaiser
- Adult Psychiatry Division, Department of Psychiatry, Geneva University Hospitals (HUG), Geneva, 1225, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, 1204, Switzerland
| | - Philippe Millet
- Adult Psychiatry Division, Department of Psychiatry, Geneva University Hospitals (HUG), Geneva, 1225, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, 1204, Switzerland
| | - Benjamin B Tournier
- Adult Psychiatry Division, Department of Psychiatry, Geneva University Hospitals (HUG), Geneva, 1225, Switzerland.,Faculty of Medicine, University of Geneva, Geneva, 1204, Switzerland
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Savi FF, de Oliveira A, de Medeiros GF, Bozza FA, Michels M, Sharshar T, Dal-Pizzol F, Ritter C. What animal models can tell us about long-term cognitive dysfunction following sepsis: A systematic review. Neurosci Biobehav Rev 2020; 124:386-404. [PMID: 33309906 DOI: 10.1016/j.neubiorev.2020.12.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 01/28/2023]
Abstract
Survivors of sepsis often develop long-term cognitive impairments. This review aimed at exploring the results of the behavioral tools and tests which have been used to evaluate cognitive dysfunction in different animal models of sepsis. Two independent investigators searched for sepsis- and cognition-related keywords. 6323 publications were found, of which 355 were selected based on their title, and 226 of these were chosen based on manuscript review. LPS was used to induce sepsis in 171 studies, while CLP was used in 55 studies. Inhibitory avoidance was the most widely used method for assessing aversive memory, followed by fear conditioning and continuous multi-trial inhibitory avoidance. With regard to non-aversive memory, most studies used the water maze, open-field, object recognition, Y-maze, plus maze, and radial maze tests. Both CLP and LPS models of sepsis were effective in inducing short- and long-term behavioral impairment. Our findings help elucidate the mechanisms involved in the pathophysiology of sepsis-induced cognitive changes, as well as the available methods and tests used to study this in animal models.
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Affiliation(s)
- Felipe Figueredo Savi
- Laboratório de Fisiopatologia Experimental, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Brazil
| | - Alexandre de Oliveira
- Laboratório de Fisiopatologia Experimental, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Brazil
| | | | - Fernando Augusto Bozza
- Laboratório de Medicina Intensiva, Instituto Nacional de Infectologia Evandro Chagas (INI), Fundação Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, Brazil
| | - Monique Michels
- Laboratório de Fisiopatologia Experimental, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Brazil
| | - Tarek Sharshar
- Laboratoire de Neuropathologie Expérimentale, Institut Pasteur, Paris, France; Department of Neuro-Intensive Care Medicine, Sainte-Anne Hospital, Paris-Descartes University, Paris, France
| | - Felipe Dal-Pizzol
- Laboratório de Fisiopatologia Experimental, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Brazil; Laboratoire de Neuropathologie Expérimentale, Institut Pasteur, Paris, France
| | - Cristiane Ritter
- Laboratório de Fisiopatologia Experimental, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Brazil.
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Zhang H, Ma L, Guo WZ, Jiao LB, Zhao HY, Ma YQ, Hao XM. TSPO ligand etifoxine attenuates LPS-induced cognitive dysfunction in mice. Brain Res Bull 2020; 165:178-184. [PMID: 33075418 DOI: 10.1016/j.brainresbull.2020.10.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/14/2020] [Accepted: 10/09/2020] [Indexed: 12/19/2022]
Abstract
The translocator protein (TSPO), once known as peripheral-type benzodiazepine receptor, was reported to be related with several physiological functions. Etifoxine is a clinically available anxiolytic drug, and has recently shown neuroprotective effects as a TSPO ligand. The aim of the present study was to investigate the influence of etifoxine on LPS-induced neuroinflammation and cognitive dysfunction. C57/BL6 male mice were injected with etifoxine (50 mg/kg, i.p.) three days before lipopolysaccharide (LPS, 500 μg/kg, i.p.) administration. Etifoxine pretreatment alleviated hippocampal inflammation, increased brain levels of progesterone, allopregnanolone and attenuated cognitive dysfunction in LPS-injected mice. While LPS increased expression of caspase-3 and decreased p-Akt/Akt, etifoxine returned caspase-3 and p-Akt/Akt to control levels. Finasteride, a 5α-reductase inhibitor that blocked allopregnanolone production, partially reversed the effects of etifoxine. We concluded that etifoxine exerted neuroprotective effects in LPS-induced neuroinflammation and the neuroprotection may be related with increase of neurosteroids synthesis and decrease of apoptosis.
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Affiliation(s)
- Hui Zhang
- Department of Neurosurgery, Air Force Medical Center of the Chinese PLA, Beijing, 100142, China.
| | - Li Ma
- Department of Anesthesiology, 7th Medical Center of the Chinese PLA General Hospital, Beijing, 100700, China
| | - Wen-Zhi Guo
- Department of Anesthesiology, 7th Medical Center of the Chinese PLA General Hospital, Beijing, 100700, China
| | - Lin-Bo Jiao
- Department of Anesthesiology, Beijing Shouda E.E.N.T Hospital, Beijing, 100070, China
| | - Hong-Yu Zhao
- Department of Anesthesiology, 7th Medical Center of the Chinese PLA General Hospital, Beijing, 100700, China
| | - Ya-Qun Ma
- Department of Anesthesiology, 7th Medical Center of the Chinese PLA General Hospital, Beijing, 100700, China
| | - Xue-Mei Hao
- Operating Room, 7th Medical Center of the Chinese PLA General Hospital, Beijing, 100700, China.
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7
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In Vivo TSPO Signal and Neuroinflammation in Alzheimer's Disease. Cells 2020; 9:cells9091941. [PMID: 32839410 PMCID: PMC7565089 DOI: 10.3390/cells9091941] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 12/15/2022] Open
Abstract
In the last decade, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) in in vivo imaging has attempted to demonstrate the presence of neuroinflammatory reactions by measuring the 18 kDa translocator protein (TSPO) expression in many diseases of the central nervous system. We focus on two pathological conditions for which neuropathological studies have shown the presence of neuroinflammation, which translates in opposite in vivo expression of TSPO. Alzheimer's disease has been the most widely assessed with more than forty preclinical and clinical studies, showing overall that TSPO is upregulated in this condition, despite differences in the topography of this increase, its time-course and the associated cell types. In the case of schizophrenia, a reduction of TSPO has instead been observed, though the evidence remains scarce and contradictory. This review focuses on the key characteristics of TSPO as a biomarker of neuroinflammation in vivo, namely, on the cellular origin of the variations in its expression, on its possible biological/pathological role and on its variations across disease phases.
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Rivera-Escalera F, Pinney JJ, Owlett L, Ahmed H, Thakar J, Olschowka JA, Elliott MR, O’Banion MK. IL-1β-driven amyloid plaque clearance is associated with an expansion of transcriptionally reprogrammed microglia. J Neuroinflammation 2019; 16:261. [PMID: 31822279 PMCID: PMC6902486 DOI: 10.1186/s12974-019-1645-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 11/18/2019] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND Neuroinflammation is thought to contribute to the pathogenesis of Alzheimer's disease (AD), yet numerous studies have demonstrated a beneficial role for neuroinflammation in amyloid plaque clearance. We have previously shown that sustained expression of IL-1β in the hippocampus of APP/PS1 mice decreases amyloid plaque burden independent of recruited CCR2+ myeloid cells, suggesting resident microglia as the main phagocytic effectors of IL-1β-induced plaque clearance. To date, however, the mechanisms of IL-1β-induced plaque clearance remain poorly understood. METHODS To determine whether microglia are involved in IL-1β-induced plaque clearance, APP/PS1 mice induced to express mature human IL-1β in the hippocampus via adenoviral transduction were treated with the Aβ fluorescent probe methoxy-X04 (MX04) and microglial internalization of fibrillar Aβ (fAβ) was analyzed by flow cytometry and immunohistochemistry. To assess microglial proliferation, APP/PS1 mice transduced with IL-1β or control were injected intraperitoneally with BrdU and hippocampal tissue was analyzed by flow cytometry. RNAseq analysis was conducted on microglia FACS sorted from the hippocampus of control or IL-1β-treated APP/PS1 mice. These microglia were also sorted based on MX04 labeling (MX04+ and MX04- microglia). RESULTS Resident microglia (CD45loCD11b+) constituted > 70% of the MX04+ cells in both Phe- and IL-1β-treated conditions, and < 15% of MX04+ cells were recruited myeloid cells (CD45hiCD11b+). However, IL-1β treatment did not augment the percentage of MX04+ microglia nor the quantity of fAβ internalized by individual microglia. Instead, IL-1β increased the total number of MX04+ microglia in the hippocampus due to IL-1β-induced proliferation. In addition, transcriptomic analyses revealed that IL-1β treatment was associated with large-scale changes in the expression of genes related to immune responses, proliferation, and cytokine signaling. CONCLUSIONS These studies show that IL-1β overexpression early in amyloid pathogenesis induces a change in the microglial gene expression profile and an expansion of microglial cells that facilitates Aβ plaque clearance.
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Affiliation(s)
- Fátima Rivera-Escalera
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 603, Rochester, NY 14642 USA
- David H. Smith Center for Vaccine Biology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY USA
| | - Jonathan J. Pinney
- David H. Smith Center for Vaccine Biology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY USA
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY USA
| | - Laura Owlett
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 603, Rochester, NY 14642 USA
- Del Monte Neuroscience Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY USA
| | - Hoda Ahmed
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 603, Rochester, NY 14642 USA
| | - Juilee Thakar
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY USA
| | - John A. Olschowka
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 603, Rochester, NY 14642 USA
- Del Monte Neuroscience Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY USA
| | - Michael R. Elliott
- David H. Smith Center for Vaccine Biology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY USA
- Department of Microbiology and Immunology, University of Rochester School of Medicine and Dentistry, Rochester, NY USA
| | - M. Kerry O’Banion
- Department of Neuroscience, University of Rochester School of Medicine and Dentistry, 601 Elmwood Avenue, Box 603, Rochester, NY 14642 USA
- Del Monte Neuroscience Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY USA
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Mendell AL, MacLusky NJ. Neurosteroid Metabolites of Gonadal Steroid Hormones in Neuroprotection: Implications for Sex Differences in Neurodegenerative Disease. Front Mol Neurosci 2018; 11:359. [PMID: 30344476 PMCID: PMC6182082 DOI: 10.3389/fnmol.2018.00359] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 09/12/2018] [Indexed: 12/12/2022] Open
Abstract
Gonadal steroid hormones are neurotrophic and neuroprotective. These effects are modulated by local metabolism of the hormones within the brain. Such control is necessary to maintain normal function, as several signaling pathways that are activated by gonadal steroid hormones in the brain can also become dysregulated in disease. Metabolites of the gonadal steroid hormones—particularly 3α-hydroxy, 5α-reduced neurosteroids—are synthesized in the brain and can act through different mechanisms from their parent steroids. These metabolites may provide a mechanism for modulating the responses to their precursor hormones, thereby providing a regulatory influence on cellular responses. In addition, there is evidence that the 3α-hydroxy, 5α-reduced neurosteroids are neuroprotective in their own right, and therefore may contribute to the overall protection conferred by their precursors. In this review article, the rapidly growing body of evidence supporting a neuroprotective role for this class of neurosteroids will be considered, including a discussion of potential mechanisms that may be involved. In addition, we explore the hypothesis that differences between males and females in local neurosteroid production may contribute to sex differences in the development of neurodegenerative disease.
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Affiliation(s)
- Ari Loren Mendell
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Neil James MacLusky
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
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10
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Notter T, Coughlin JM, Gschwind T, Weber-Stadlbauer U, Wang Y, Kassiou M, Vernon AC, Benke D, Pomper MG, Sawa A, Meyer U. Translational evaluation of translocator protein as a marker of neuroinflammation in schizophrenia. Mol Psychiatry 2018; 23:323-334. [PMID: 28093569 DOI: 10.1038/mp.2016.248] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 10/14/2016] [Accepted: 11/28/2016] [Indexed: 02/08/2023]
Abstract
Positron emission tomography (PET) imaging with radiotracers that target translocator protein 18 kDa (TSPO) has become a popular approach to assess putative neuroinflammatory processes and associated microglia activation in psychotic illnesses. It remains unclear, however, whether TSPO imaging can accurately capture low-grade inflammatory processes such as those present in schizophrenia and related disorders. Therefore, we evaluated the validity of TSPO as a disease-relevant marker of inflammation using a translational approach, which combined neurodevelopmental and neurodegenerative mouse models with PET imaging in patients with recent-onset schizophrenia and matched controls. Using an infection-mediated neurodevelopmental mouse model, we show that schizophrenia-relevant behavioral abnormalities and increased inflammatory cytokine expression are associated with reduced prefrontal TSPO levels. On the other hand, TSPO was markedly upregulated in a mouse model of acute neurodegeneration and reactive gliosis, which was induced by intrahippocampal injection of kainic acid. In both models, the changes in TSPO levels were not restricted to microglia but emerged in various cell types, including microglia, astrocytes and vascular endothelial cells. Human PET imaging using the second-generation TSPO radiotracer [11C]DPA-713 revealed a strong trend towards reduced TSPO binding in the middle frontal gyrus of patients with recent-onset schizophrenia, who were previously shown to display increased levels of inflammatory cytokines in peripheral and central tissues. Together, our findings challenge the common assumption that central low-grade inflammation in schizophrenia is mirrored by increased TSPO expression or ligand binding. Our study further underscores the need to interpret altered TSPO binding in schizophrenia with caution, especially when measures of TSPO are not complemented with other markers of inflammation. Unless more selective microglial markers are available for PET imaging, quantification of cytokines and other inflammatory biomarkers, along with their molecular signaling pathways, may be more accurate in attempts to characterize inflammatory profiles in schizophrenia and other mental disorders that lack robust reactive gliosis.
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Affiliation(s)
- T Notter
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
| | - J M Coughlin
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - T Gschwind
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - U Weber-Stadlbauer
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
| | - Y Wang
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - M Kassiou
- School of Chemistry, The University of Sydney, Sydney, NSW, Australia
- Discipline of Medical Radiation Sciences, The University of Sydney, Sydney, NSW, Australia
| | - A C Vernon
- MRC Centre for Neurodevelopmental Disorders, King's College London, London, UK
- King's College London, Institute of Psychiatry Psychology and Neuroscience, Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, London, UK
| | - D Benke
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - M G Pomper
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - A Sawa
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Medical Institutions, Baltimore, MD, USA
| | - U Meyer
- Institute of Pharmacology and Toxicology, University of Zurich-Vetsuisse, Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, Zurich, Switzerland
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11
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Kupa LDVK, Drewes CC, Barioni ED, Neves CL, Sampaio SC, Farsky SHP. Role of Translocator 18 KDa Ligands in the Activation of Leukotriene B4 Activated G-Protein Coupled Receptor and Toll Like Receptor-4 Pathways in Neutrophils. Front Pharmacol 2017; 8:766. [PMID: 29163156 PMCID: PMC5664262 DOI: 10.3389/fphar.2017.00766] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 10/11/2017] [Indexed: 12/13/2022] Open
Abstract
TSPO (Translocator 18 KDa; tryptophan-rich sensory protein oxygen sensor) is a constitutive outer mitochondrial membrane protein overexpressed in inflammatory cells during local or systemic processes. Despite its expression is characterized, role of TSPO in inflammation remains elusive. For this study, we investigated the role of TSPO ligands on neutrophil functions elicited by two different inflammatory pathways. Peritoneal neutrophils were isolated from male Balb-C mice, treated with TSPO ligand diazepam, Ro5-4864 or PK11195 (1,100 or 1000 nM; 2 h) and further stimulated with lipopolysaccharide from Escherichia coli (LPS), a binding for Toll-Like Receptor-4 (TLR4), or leukotriene B4 (LTB4), a G-protein coupled receptor (GPCR) ligand. LPS treatment did not lead to overexpression of TSPO on neutrophils, and pre-treatment with any TSPO ligand did not alter cytokine expression, adhesion molecule expression, or the production of reactive oxygen and nitrogen species caused by LPS stimulation. Conversely, all TSPO ligands impaired LTB4’s actions, as visualized by reductions in L-selectin shedding, β2 integrin overexpression, neutrophil chemotaxis, and actin filament assembly. TSPO ligands showed distinct intracellular effects on LTB4-induced neutrophil locomotion, with diazepam enhancing cofilin but not modifying Arp2/3 expression, and Ro5-4864 and PK11195 reducing both cofilin and Arp2/3 expression. Taken together, our data exclude a direct role of TSPO ligands in TLR4-elicited pathways, and indicate that TSPO activation inhibits GPCR inflammatory pathways in neutrophils, with a relevant role in neutrophil influx into inflammatory sites.
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Affiliation(s)
- Léonard de Vinci Kanda Kupa
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Carine C Drewes
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Eric D Barioni
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
| | - Camila L Neves
- Laboratory of Pathophysiology, Institute Butantan, São Paulo, Brazil
| | | | - Sandra H P Farsky
- Department of Clinical and Toxicological Analyses, School of Pharmaceutical Sciences, University of São Paulo, São Paulo, Brazil
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Overexpression of the 18 kDa translocator protein (TSPO) in the hippocampal dentate gyrus produced anxiolytic and antidepressant-like behavioural effects. Neuropharmacology 2017; 125:117-128. [PMID: 28655607 DOI: 10.1016/j.neuropharm.2017.06.023] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 06/18/2017] [Accepted: 06/22/2017] [Indexed: 12/22/2022]
Abstract
The 18 kDa translocator protein (TSPO) is a five transmembrane domain protein that plays a crucial role in neurosteroid (e.g., allopregnanolone) synthesis by promoting the transport of cholesterol to the inner mitochondrial membrane. This protein is predominantly expressed in steroid-synthesizing tissues, including the central and peripheral nervous system, affecting stress-related disorders such as anxiety and depression. Recent studies have focused on the hippocampal dentate gyrus, which is very important for involvement of anxiety and depression. However, the exact role that TSPO plays in the pathophysiology of anxiety and depression and the involvement of the hippocampal dentate gyrus in regulating these behavioural effects remain elusive. This study used the lentiviral vectors mediating TPSO overexpression to assess the effects of TPSO overexpression in the hippocampal dentate gyrus on anxiolytic and antidepressant-like behavioural effects in mice. The expression of TSPO and the concentration of allopregnanolone in hippocampus tissues (3 mm in diameter around the injection site on both sides) were measured by Western blot and ELISA, respectively. The results indicated that microinjection of the LV-TSPO resulted in a significant increase in TSPO expression and allopregnanolone concentration in the hippocampus. Moreover, TSPO overexpression of the mouse hippocampal dentate gyrus generated significant anxiolytic and antidepressant-like behavioural effects in a series of behavioural models. These effects were completely blocked by the TSPO antagonist PK11195 (3 mg/kg, intraperitoneally) and the 5α-reductase inhibitor finasteride (5 mg/kg,intraperitoneally). Meanwhile, the increased allopregnanolone was also reversed by PK11195 and finasteride. In addition, neither PK11195 nor finasteride had an effect on the expression of TSPO. Overall, our results are the first to suggest that the overexpression of TSPO in the hippocampal dentate gyrus produced anxiolytic and antidepressant-like behavioural effects that are partially mediated by downstream allopregnanolone biosynthesis. Our results suggest that TSPO would be a potential anxiolytic and antidepressant therapeutic target.
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余 军, 赵 维, 杜 春, 张 娜, 张 卫, 晋 圣, 汪 海, 冯 泽. [Choline improves lipopolysaccharide-induced central nervous system inflammatory response and cognitive dysfunction in mice]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2017; 37:600-606. [PMID: 28539281 PMCID: PMC6780474 DOI: 10.3969/j.issn.1673-4254.2017.05.06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Indexed: 06/07/2023]
Abstract
OBJECTIVE To assess the effect of choline in ameliorating lipopolysaccharide (LPS)-induced central nervous system inflammation and cognitive deficits in mice and explore the underlying mechanism. METHODS Seventy-two mice were randomized into saline control group, LPS group, choline intervention group and choline control group. In the latter two groups, the mice received pretreatment with intraperitoneal injections of choline (40 mg/kg, 3 times daily for 3 consecutive days) prior to microinjection of LPS into the lateral cerebral ventricle to induce central nervous system inflammation; in saline and LPS groups, the mice were pretreated with saline in the same manner before intraventicular injection of artificial cerebrospinal fluid. Choline treatment was administered in the mice till the end of the experiment. The locomotor activity and spatial learning and memory capacity of the mice were examined. The expressions of Iba1 protein and proinflammatory cytokines (TNF-α and IL-β) I the hippocampal dentate gyrus, and the expressions of α 7nAchR, p38 MAPK and phosphorylated p38 MAPK in the hippocampus of the mice were detected. RESULTS Water maze test showed that compared with the saline control group, the mice in LPS group exhibited significantly reduced platform crossings (P<0.05), which was significantly increased by choline pretreatment (P<0.05). The mice pretreated with LPS expressed obviously increased levels of IBA-1 protein, TNF-α, and IL-1β in the hippocampus (P<0.01), and choline pretreatment significantly lowered the expressions of IBA-1 protein and IL-1β (P<0.05). The phosphorylation level of p38 MAPK increased significantly after LPS pretreatment (P<0.05), and was reduced by choline pretreatment (P<0.05); α 7nAchR expression increased significantly in choline intervention group as compared with that in the other 3 groups (P<0.05). CONCLUSION Choline can probably antagonize LPS-induced hippocampal p38 MAPK phosphorylation in mice via the α 7nAchR signaling pathway to protective against LPS-induced neuroinflammation and cognitive impairment in mice.
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Affiliation(s)
- 军 余
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 维星 赵
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 春彦 杜
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 娜 张
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 卫东 张
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
| | - 圣阳 晋
- 中国医学科学院北京协和医学院,北京 100730Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100730, China
| | - 海 汪
- 军事医学科学院卫生学环境医学研究所心血管药物研究中心,北京 100850Cardiovascular Drug Research Center, Institute of Hea1th and Environmental Medicine, Academy of Military Medical Sciences, Beijing 100850, China
| | - 泽国 冯
- 解放军总医院麻醉手术中心,北京 100853Department of Anesthesiology and Operation Center, General Hospital of PLA, Beijing 100853, China
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Kalk NJ, Guo Q, Owen D, Cherian R, Erritzoe D, Gilmour A, Ribeiro AS, McGonigle J, Waldman A, Matthews P, Cavanagh J, McInnes I, Dar K, Gunn R, Rabiner EA, Lingford-Hughes AR. Decreased hippocampal translocator protein (18 kDa) expression in alcohol dependence: a [ 11C]PBR28 PET study. Transl Psychiatry 2017; 7:e996. [PMID: 28072413 PMCID: PMC5545729 DOI: 10.1038/tp.2016.264] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 11/02/2016] [Accepted: 11/13/2016] [Indexed: 01/05/2023] Open
Abstract
Repeated withdrawal from alcohol is clinically associated with progressive cognitive impairment. Microglial activation occurring during pre-clinical models of alcohol withdrawal is associated with learning deficits. We investigated whether there was microglial activation in recently detoxified alcohol-dependent patients (ADP), using [11C]PBR28 positron emission tomography (PET), selective for the 18kDa translocator protein (TSPO) highly expressed in activated microglia and astrocytes. We investigated the relationship between microglial activation and cognitive performance. Twenty healthy control (HC) subjects (45±13; M:F 14:6) and nine ADP (45±6, M:F 9:0) were evaluated. Dynamic PET data were acquired for 90 min following an injection of 331±15 MBq [11C]PBR28. Regional volumes of distribution (VT) for regions of interest (ROIs) identified a priori were estimated using a two-tissue compartmental model with metabolite-corrected arterial plasma input function. ADP had an ~20% lower [11C]PBR28 VT, in the hippocampus (F(1,24) 5.694; P=0.025), but no difference in VT in other ROIs. Hippocampal [11C]PBR28 VT was positively correlated with verbal memory performance in a combined group of HC and ADP (r=0.720, P<0.001), an effect seen in HC alone (r=0.738; P=0.001) but not in ADP. We did not find evidence for increased microglial activation in ADP, as seen pre-clinically. Instead, our findings suggest lower glial density or an altered activation state with lower TSPO expression. The correlation between verbal memory and [11C]PBR28 VT, raises the possibility that abnormalities of glial function may contribute to cognitive impairment in ADP.
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Affiliation(s)
- N J Kalk
- National Addictions Centre, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, London, UK,National Addictions Centre, Institute of Psychiatry, Psychology and Neuroscience, Kings College London, 4 Windsor Walk, London SE5 8BB, UK. E-mail:
| | - Q Guo
- Neuroimaging Department, Kings College London, London, UK,Centre for Neuropsychopharmacology, Imperial College London, London, UK
| | - D Owen
- Division of Brain Sciences, Imperial College London, London, UK
| | - R Cherian
- West London Mental Health NHS Trust, London, UK
| | - D Erritzoe
- Centre for Neuropsychopharmacology, Imperial College London, London, UK
| | - A Gilmour
- Centre for Infection, Inflammation and Immunity, University of Glasgow, Glasgow, UK
| | - A S Ribeiro
- Centre for Neuropsychopharmacology, Imperial College London, London, UK
| | - J McGonigle
- Centre for Neuropsychopharmacology, Imperial College London, London, UK
| | - A Waldman
- Division of Brain Sciences, Imperial College London, London, UK
| | - P Matthews
- Division of Brain Sciences, Imperial College London, London, UK
| | - J Cavanagh
- Institute of Health and Well-being, University of Glasgow, Glasgow, UK
| | - I McInnes
- Centre for Infection, Inflammation and Immunity, University of Glasgow, Glasgow, UK
| | - K Dar
- Central and North West London NHS Trust, London, UK
| | - R Gunn
- Imanova Limited, London, UK
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