51
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Ma Z, Guo X, Liu J. Translocator protein mediates olfactory repulsion. FASEB J 2020; 34:513-524. [PMID: 31914587 DOI: 10.1096/fj.201900528rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 10/14/2019] [Accepted: 10/21/2019] [Indexed: 11/11/2022]
Abstract
Translocator protein (TSPO, 18kDa), which was previously known as a peripheral-type benzodiazepine receptor, is associated with psychiatric disorders and acts as a neuroimaging biomarker. However, its function and mechanism in modulating behaviors are less well-known. Herein, we found that TSPO in migratory locusts shows conserved protein traits and is expressed at high levels in the brains. The expression levels of tspo mRNA and protein were higher in brains of solitary locusts than those in gregarious locusts, whereas the mRNA and protein expression levels remained stable during crowding and isolation, suggesting that the expression level of TSPO is potentially associated with behavioral phenotype of solitary locusts. Moreover, tspo RNAi knockdown in the brains of solitary locusts decreased their olfactory repulsion. After RNAi knockdown of tyramine receptor (TyR) in the brains of solitary locusts, RNA-seq analysis identified that a functional class of receptors, which included tspo, was downregulated significantly. Moreover, tspo mRNA and protein expression levels were downregulated and upregulated after TyR RNAi knockdown and activation, respectively. tspo RNAi knockdown in the brains of solitary locusts induced the attractive response and inhibited the function of tyramine (TA)-TyR in inducing olfactory repulsion. In gregarious locusts, tspo RNAi knockdown inhibited the function of TA-TyR inducing olfactory repulsion. This study confirms that TSPO acts as a crucial effector protein in TA-TyR signaling to modulate olfactory repulsion. Furthermore, this study provides a novel mechanism by which TSPO functionally connects a G-protein-coupled receptor and a mitochondria membrane protein in modulating olfactory repulsion.
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Affiliation(s)
- Zongyuan Ma
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Xiaojiao Guo
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
| | - Jipeng Liu
- Beijing Institutes of Life Science, Chinese Academy of Sciences, Beijing, China
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52
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Isaac-Lam MF, Hammonds DM. Synthesis and Photodynamic Activity of Vitamin-Chlorin Conjugates at Nanomolar Concentrations against Prostate Cancer Cells. ACS OMEGA 2019; 4:21712-21723. [PMID: 31891050 PMCID: PMC6933591 DOI: 10.1021/acsomega.9b02394] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 11/06/2019] [Indexed: 05/11/2023]
Abstract
Phototoxicity response of synthesized vitamin-chlorin conjugates and their zinc and indium complexes was determined in the human PC-3 prostate cancer cell line, which was previously demonstrated to overexpress vitamin receptors on the cell surface. Pantothenic acid (Vit B5) and lipoic acid (or thioctic acid) were covalently linked to methyl pheophorbide (a chlorophyll derivative) and subsequently metallated with zinc and indium. Cell survival assay indicated that the vitamin-chlorin conjugates have better photodynamic activity against the PC-3 prostate cancer line at the nanomolar concentration range than the commercially available starting precursor methyl pheophorbide. Fluorescence and transmission electron microscopy studies indicated some formation of apoptotic cells and cytoplasmic vacuoles of photosensitized prostatic cells. Targeting vitamin receptors in prostatic cancer cells can be utilized to enhance specificity of photosensitizers for photodynamic therapy applications.
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Affiliation(s)
- Meden F. Isaac-Lam
- Department of Chemistry and Physics, Purdue University Northwest, 1401 S US Hwy 421, Westville, Indiana 46391, United
States
| | - Dewana M. Hammonds
- Department of Chemistry and Physics, Purdue University Northwest, 1401 S US Hwy 421, Westville, Indiana 46391, United
States
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53
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Fantin SM, Parson KF, Niu S, Liu J, Polasky DA, Dixit SM, Ferguson-Miller SM, Ruotolo BT. Collision Induced Unfolding Classifies Ligands Bound to the Integral Membrane Translocator Protein. Anal Chem 2019; 91:15469-15476. [PMID: 31743004 DOI: 10.1021/acs.analchem.9b03208] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Membrane proteins represent most current therapeutic targets, yet remain understudied due to their insolubility in aqueous solvents and generally low yields during purification and expression. Ion mobility-mass spectrometry and collision induced unfolding experiments have recently garnered attention as methods capable of directly detecting and quantifying ligand binding within a wide range of membrane protein systems. Despite prior success, ionized surfactant often creates chemical noise patterns resulting in significant challenges surrounding the study of small membrane protein-ligand complexes. Here, we present a new data analysis workflow that overcomes such chemical noise and then utilize this approach to quantify and classify ligand binding associated with the 36 kDa dimer of translocator protein (TSPO). Following our denoising protocol, we detect separate gas-phase unfolding signatures for lipid and protoporphyrin TSPO binders, molecular classes that likely interact with separate regions of the protein surface. Further, a detailed classification analysis reveals that lipid alkyl chain saturation levels can be detected within our gas-phase protein unfolding data. We combine these data and classification schemes with mass spectra acquired directly from liquid-liquid extracts to propose an identity for a previously unknown endogenous TSPO ligand.
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Affiliation(s)
- Sarah M Fantin
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Kristine F Parson
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Shuai Niu
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Jian Liu
- Department of Biochemistry and Molecular Biology , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Daniel A Polasky
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Sugyan M Dixit
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
| | - Shelagh M Ferguson-Miller
- Department of Biochemistry and Molecular Biology , Michigan State University , East Lansing , Michigan 48824 , United States
| | - Brandon T Ruotolo
- Department of Chemistry , University of Michigan , Ann Arbor , Michigan 48109 , United States
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54
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Characterisation of the ligand binding sites in the translocator protein TSPO using the chimeric bacterial-mammalian constructs. Protein Expr Purif 2019; 164:105456. [DOI: 10.1016/j.pep.2019.105456] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/18/2019] [Accepted: 07/12/2019] [Indexed: 01/18/2023]
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55
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Dias IH, Borah K, Amin B, Griffiths HR, Sassi K, Lizard G, Iriondo A, Martinez-Lage P. Localisation of oxysterols at the sub-cellular level and in biological fluids. J Steroid Biochem Mol Biol 2019; 193:105426. [PMID: 31301352 DOI: 10.1016/j.jsbmb.2019.105426] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/25/2019] [Accepted: 07/09/2019] [Indexed: 12/16/2022]
Abstract
Oxysterols are oxidized derivatives of cholesterol that are formed enzymatically or via reactive oxygen species or both. Cholesterol or oxysterols ingested as food are absorbed and packed into lipoproteins that are taken up by hepatic cells. Within hepatic cells, excess cholesterol is metabolised to form bile acids. The endoplasmic reticulum acts as the main organelle in the bile acid synthesis pathway. Metabolised sterols originating from this pathway are distributed within other organelles and in the cell membrane. The alterations to membrane oxysterol:sterol ratio affects the integrity of the cell membrane. The presence of oxysterols changes membrane fluidity and receptor orientation. It is well documented that hydroxylase enzymes located in mitochondria facilitate oxysterol production via an acidic pathway. More recently, the presence of oxysterols was also reported in lysosomes. Peroxisomal deficiencies favour intracellular oxysterols accumulation. Despite the low abundance of oxysterols compared to cholesterol, the biological actions of oxysterols are numerous and important. Oxysterol levels are implicated in the pathogenesis of multiple diseases ranging from chronic inflammatory diseases (atherosclerosis, Alzheimer's disease and bowel disease), cancer and numerous neurodegenerative diseases. In this article, we review the distribution of oxysterols in sub-cellular organelles and in biological fluids.
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Affiliation(s)
- Irundika Hk Dias
- Aston Medical Research Institute, Aston Medical School, Aston University, Birmingham, B4 7ET, UK.
| | - Khushboo Borah
- Faculty of Health and Medical Sciences, University of Surrey, Stag Hill, Guildford, GU2 7XH, UK
| | - Berivan Amin
- Aston Medical Research Institute, Aston Medical School, Aston University, Birmingham, B4 7ET, UK
| | - Helen R Griffiths
- Aston Medical Research Institute, Aston Medical School, Aston University, Birmingham, B4 7ET, UK; Faculty of Health and Medical Sciences, University of Surrey, Stag Hill, Guildford, GU2 7XH, UK
| | - Khouloud Sassi
- Team Bio-PeroxIL, Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism (EA7270)/University Bourgogne Franche-Comté/Inserm, 21000 Dijon, France; Univ. Tunis El Manar, Laboratory of Onco-Hematology (LR05ES05), Faculty of Medicine, Tunis, Tunisia
| | - Gérard Lizard
- Team Bio-PeroxIL, Biochemistry of the Peroxisome, Inflammation and Lipid Metabolism (EA7270)/University Bourgogne Franche-Comté/Inserm, 21000 Dijon, France
| | - Ane Iriondo
- Department of Neurology, Center for Research and Advanced Therapies, CITA-Alzheimer Foundation, San Sebastian, Spain
| | - Pablo Martinez-Lage
- Department of Neurology, Center for Research and Advanced Therapies, CITA-Alzheimer Foundation, San Sebastian, Spain
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56
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Leung MCK, Meyer JN. Mitochondria as a target of organophosphate and carbamate pesticides: Revisiting common mechanisms of action with new approach methodologies. Reprod Toxicol 2019; 89:83-92. [PMID: 31315019 PMCID: PMC6766410 DOI: 10.1016/j.reprotox.2019.07.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 06/19/2019] [Accepted: 07/09/2019] [Indexed: 01/01/2023]
Abstract
Mitochondrial toxicity has been proposed as a potential cause of developmental defects in humans. We evaluated 51 organophosphate and carbamate pesticides using the U.S. EPA ToxCast and Tox21 databases. Only a small number of them bind directly to cholinesterases in the parent form. The hydrophobicity of organophosphate pesticides is correlated significantly to TSPO binding affinity, mitochondrial membrane potential reduction in HepG2 cells, and developmental toxicity in Caenorhabditis elegans and Danio rerio (p < 0.05). Structural analysis suggests that in some cases the Krebs cycle is a potential target of organophosphate and carbamate exposure at early life stages. The results support the hypothesis that mitochondrial effects of some organophosphate pesticides-particularly those that require enzymatic activation to the oxon form-may augment the documented effects of disruption of acetylcholine signaling. This study provides a proof of concept for applying new approach methodologies to interrogate mechanisms of action for cumulative risk assessment.
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Affiliation(s)
- Maxwell C K Leung
- Department of Environmental Toxicology, University of California, Davis, CA, United States; Nicholas School of the Environment, Duke University, Durham, NC, United States.
| | - Joel N Meyer
- Nicholas School of the Environment, Duke University, Durham, NC, United States
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57
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Bruno A, Barresi E, Simola N, Da Pozzo E, Costa B, Novellino E, Da Settimo F, Martini C, Taliani S, Cosconati S. Unbinding of Translocator Protein 18 kDa (TSPO) Ligands: From in Vitro Residence Time to in Vivo Efficacy via in Silico Simulations. ACS Chem Neurosci 2019; 10:3805-3814. [PMID: 31268683 DOI: 10.1021/acschemneuro.9b00300] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Translocator protein 18 kDa (TSPO) is a validated pharmacological target for the development of new treatments for neurological disorders. N,N-Dialkyl-2-phenylindol-3-ylglyoxylamides (PIGAs) are effective TSPO modulators and potentially useful therapeutics for the treatment of anxiety, central nervous system pathologies featuring astrocyte loss, and inflammatory-based neuropathologies. For this class of compounds, no correlation exists between the TSPO binding affinity and the corresponding functional efficacy. Rather, their biological effectiveness correlates with the kinetics of the unbinding events and more specifically with the residence time (RT). So far, the structural reasons for the different recorded RT of congeneric PIGAs remain elusive. Here, to understand the different kinetics of PIGAs, their unbinding paths were studied by employing enhanced-sampling molecular dynamics simulations. Results of these studies revealed how subtle structural differences between PIGAs have a substantial effect on the unbinding energetics. In particular, during the egress from the TSPO binding site, slow-dissociating PIGAs find tight interactions with the protein LP1 region thereby determining a long RT. Further support to these findings was achieved by in vivo studies, which demonstrated how the anxiolytic effect observed for the inspected PIGAs correlated with their RT to TSPO.
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Affiliation(s)
- Agostino Bruno
- Department of Pharmacy, University Federico II of Naples, Via D. Montesano 49, 80131 Naples, Italy
| | - Elisabetta Barresi
- Department of Pharmacy, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Nicola Simola
- Department of Biomedical Sciences, University of Cagliari, Monserrato University Campus, 09042 Monserrato, Italy
| | - Eleonora Da Pozzo
- Department of Pharmacy, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Barbara Costa
- Department of Pharmacy, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Ettore Novellino
- Department of Pharmacy, University Federico II of Naples, Via D. Montesano 49, 80131 Naples, Italy
| | - Federico Da Settimo
- Department of Pharmacy, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Claudia Martini
- Department of Pharmacy, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Sabrina Taliani
- Department of Pharmacy, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Sandro Cosconati
- DiSTABiF, University of Campania “Luigi Vanvitelli”, Via Vivaldi 43, 81100 Caserta, Italy
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58
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Shoshan-Barmatz V, Pittala S, Mizrachi D. VDAC1 and the TSPO: Expression, Interactions, and Associated Functions in Health and Disease States. Int J Mol Sci 2019; 20:ijms20133348. [PMID: 31288390 PMCID: PMC6651789 DOI: 10.3390/ijms20133348] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 12/12/2022] Open
Abstract
The translocator protein (TSPO), located at the outer mitochondrial membrane (OMM), serves multiple functions and contributes to numerous processes, including cholesterol import, mitochondrial metabolism, apoptosis, cell proliferation, Ca2+ signaling, oxidative stress, and inflammation. TSPO forms a complex with the voltage-dependent anion channel (VDAC), a protein that mediates the flux of ions, including Ca2+, nucleotides, and metabolites across the OMM, controls metabolism and apoptosis and interacts with many proteins. This review focuses on the two OMM proteins TSPO and VDAC1, addressing their structural interaction and associated functions. TSPO appears to be involved in the generation of reactive oxygen species, proposed to represent the link between TSPO activation and VDAC, thus playing a role in apoptotic cell death. In addition, expression of the two proteins in healthy brains and diseased states is considered, as is the relationship between TSPO and VDAC1 expression. Both proteins are over-expressed in in brains from Alzheimer’s disease patients. Finally, TSPO expression levels were proposed as a biomarker of some neuropathological settings, while TSPO-interacting ligands have been considered as a potential basis for drug development.
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Affiliation(s)
- Varda Shoshan-Barmatz
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
| | - Srinivas Pittala
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Dario Mizrachi
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602, USA
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59
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Tyler RE, Kim SW, Guo M, Jang YJ, Damadzic R, Stodden T, Vendruscolo LF, Koob GF, Wang GJ, Wiers CE, Volkow ND. Detecting neuroinflammation in the brain following chronic alcohol exposure in rats: A comparison between in vivo and in vitro TSPO radioligand binding. Eur J Neurosci 2019; 50:1831-1842. [PMID: 30803059 PMCID: PMC10714130 DOI: 10.1111/ejn.14392] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 01/17/2019] [Accepted: 02/08/2019] [Indexed: 12/18/2022]
Abstract
Excessive alcohol consumption is associated with neuroinflammation, which likely contributes to alcohol-related pathology. However, positron emission tomography (PET) studies using radioligands for the 18-kDa translocator protein (TSPO), which is considered a biomarker of neuroinflammation, reported decreased binding in alcohol use disorder (AUD) participants compared to controls. In contrast, autoradiographic findings in alcohol exposed rats reported increases in TSPO radioligand binding. To assess if these discrepancies reflected differences between in vitro and in vivo methodologies, we compared in vitro autoradiography (using [3 H]PBR28 and [3 H]PK11195) with in vivo PET (using [11 C]PBR28) in male, Wistar rats exposed to chronic alcohol-vapor (dependent n = 10) and in rats exposed to air-vapor (nondependent n = 10). PET scans were obtained with [11 C]PBR28, after which rats were euthanized and the brains were harvested for autoradiography with [3 H]PBR28 and [3 H]PK11195 (n = 7 dependent and n = 7 nondependent), and binding quantified in hippocampus, thalamus, and parietal cortex. Autoradiography revealed significantly higher binding in alcohol-dependent rats for both radioligands in thalamus and hippocampus (trend level for [3 H]PBR28) compared to nondependent rats, and these group differences were stronger for [3 H]PK11195 than [3 H]PBR28. In contrast, PET measures obtained in the same rats showed no group difference in [11 C]PBR28 binding. Our in vitro data are consistent with neuroinflammation associated with chronic alcohol exposure. Failure to observe similar increases in [11 C]PBR28 binding in vivo suggests the possibility that a mechanism mediated by chronic alcohol exposure interferes with [11 C]PBR28 binding to TSPO in vivo. These data question the sensitivity of PBR28 PET as a methodology to assess neuroinflammation in AUD.
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Affiliation(s)
- Ryan E. Tyler
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
| | - Sung Won Kim
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
| | - Min Guo
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
| | - Yeon Joo Jang
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
| | - Ruslan Damadzic
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
| | - Tyler Stodden
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
| | - Leandro F. Vendruscolo
- National Institute on Drug Abuse, National Institutes of Health, NIH, Baltimore, Maryland
| | - George F. Koob
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
- National Institute on Drug Abuse, National Institutes of Health, NIH, Baltimore, Maryland
| | - Gene-Jack Wang
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
| | - Corinde E. Wiers
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
| | - Nora D. Volkow
- National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, Maryland
- National Institute on Drug Abuse, National Institutes of Health, NIH, Baltimore, Maryland
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60
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Investigating targets for neuropharmacological intervention by molecular dynamics simulations. Biochem Soc Trans 2019; 47:909-918. [PMID: 31085614 DOI: 10.1042/bst20190048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 04/11/2019] [Accepted: 04/23/2019] [Indexed: 01/09/2023]
Abstract
Medical research has identified over 500 brain disorders. Among these, there are still only very few neuropathologies whose causes are fully understood and, consequently, very few drugs whose mechanism of action is known. No FDA drug has been identified for major neurodegenerative diseases, such as Alzheimer's and Parkinson's. We still lack effective treatments and strategies for modulating progression or even early neurodegenerative disease onset diagnostic tools. A great support toward the highly needed identification of neuroactive drugs comes from computer simulation methods and, in particular, from molecular dynamics (MD). This provides insight into structure-function relationship of a target and predicts structure, dynamics and energetics of ligand/target complexes under biologically relevant conditions like temperature and physiological saline concentration. Here, we present examples of the predictive power of MD for neuroactive ligands/target complexes. This brief survey from our own research shows the usefulness of partnerships between academia and industry, and from joint efforts between experimental and theoretical groups.
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Inhibitory Effects of the Two Novel TSPO Ligands 2-Cl-MGV-1 and MGV-1 on LPS-induced Microglial Activation. Cells 2019; 8:cells8050486. [PMID: 31121852 PMCID: PMC6562711 DOI: 10.3390/cells8050486] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2019] [Revised: 05/16/2019] [Accepted: 05/17/2019] [Indexed: 02/06/2023] Open
Abstract
The 18 kDa translocator protein (TSPO) ligands 2-Cl-MGV-1 and MGV-1 can attenuate cell death of astrocyte-like cells (U118MG) and induce differentiation of neuronal progenitor cells (PC-12). Lipopolysaccharide (LPS) is a bacterial membrane endotoxin that activates cellular inflammatory pathways by releasing pro-inflammatory molecules, including cytokines and chemokines. The aim of the present study was to assess the immuno-modulatory effect of TSPO ligands in activated microglial cells. We demonstrated that the TSPO ligands 2-Cl-MGV-1 and MGV-1 can prevent LPS-induced activation of microglia (BV-2 cell line). Co-treatment of LPS (100 ng/mL) with these TSPO ligands (final concentration- 25 µM) reduces significantly the LPS-induced release of interleukin-6 (IL-6) from 16.9-fold to 2.5-fold, IL-β from 8.3-fold to 1.6-fold, interferon-γ from 16.0-fold to 2.2-fold, and tumor necrosis factor-α from 16.4-fold to 1.8-fold. This anti-inflammatory activity seems to be achieved by inhibition of NF-κB p65 activation. Assessment of initiation of ROS generation and cell metabolism shows significant protective effects of these two novel TSPO ligands. The IL-10 and IL-13 levels were not affected by any of the TSPO ligands. Thus, it appears that the ligands suppress the LPS-induced activation of some inflammatory responses of microglia. Such immunomodulatory effects may be relevant to the pharmacotherapy of neuro-inflammatory diseases.
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62
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Mitochondria in Neuroprotection by Phytochemicals: Bioactive Polyphenols Modulate Mitochondrial Apoptosis System, Function and Structure. Int J Mol Sci 2019; 20:ijms20102451. [PMID: 31108962 PMCID: PMC6566187 DOI: 10.3390/ijms20102451] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 05/11/2019] [Accepted: 05/15/2019] [Indexed: 12/15/2022] Open
Abstract
In aging and neurodegenerative diseases, loss of distinct type of neurons characterizes disease-specific pathological and clinical features, and mitochondria play a pivotal role in neuronal survival and death. Mitochondria are now considered as the organelle to modulate cellular signal pathways and functions, not only to produce energy and reactive oxygen species. Oxidative stress, deficit of neurotrophic factors, and multiple other factors impair mitochondrial function and induce cell death. Multi-functional plant polyphenols, major groups of phytochemicals, are proposed as one of most promising mitochondria-targeting medicine to preserve the activity and structure of mitochondria and neurons. Polyphenols can scavenge reactive oxygen and nitrogen species and activate redox-responsible transcription factors to regulate expression of genes, coding antioxidants, anti-apoptotic Bcl-2 protein family, and pro-survival neurotrophic factors. In mitochondria, polyphenols can directly regulate the mitochondrial apoptosis system either in preventing or promoting way. Polyphenols also modulate mitochondrial biogenesis, dynamics (fission and fusion), and autophagic degradation to keep the quality and number. This review presents the role of polyphenols in regulation of mitochondrial redox state, death signal system, and homeostasis. The dualistic redox properties of polyphenols are associated with controversial regulation of mitochondrial apoptosis system involved in the neuroprotective and anti-carcinogenic functions. Mitochondria-targeted phytochemical derivatives were synthesized based on the phenolic structure to develop a novel series of neuroprotective and anticancer compounds, which promote the bioavailability and effectiveness. Phytochemicals have shown the multiple beneficial effects in mitochondria, but further investigation is required for the clinical application.
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63
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Winkel BM, de Korne CM, van Oosterom MN, Staphorst D, Bunschoten A, Langenberg MC, Chevalley-Maurel SC, Janse CJ, Franke-Fayard B, van Leeuwen FW, Roestenberg M. A tracer-based method enables tracking of Plasmodium falciparum malaria parasites during human skin infection. Theranostics 2019; 9:2768-2778. [PMID: 31244921 PMCID: PMC6568182 DOI: 10.7150/thno.33467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 02/22/2019] [Indexed: 11/10/2022] Open
Abstract
Introduction: The skin stage of malaria is a vital and vulnerable migratory life stage of the parasite. It has been characterised in rodent models, but remains wholly uninvestigated for human malaria parasites. To enable in depth analysis of not genetically modified (non-GMO) Plasmodium falciparum (Pf) sporozoite behaviour in human skin, we devised a labelling technology (Cy5M2, targeting the sporozoite mitochondrion) that supports tracking of individual non-GMO sporozoites in human skin. Methods: Sporozoite labelling with Cy5M2 was performed in vitro as well as via the feed of infected Anopheles mosquitos. Labelling was validated using confocal microscopy and flow cytometry and the fitness of labelled sporozoites was determined by analysis of infectivity to human hepatocytes in vitro, and in vivo in a rodent infection model. Using confocal video microscopy and custom software, single-sporozoite tracking studies in human skin-explants were performed. Results: Both in vitro and in mosquito labelling strategies yielded brightly fluorescent sporozoites of three different Plasmodium species. Cy5M2 uptake colocalized with MitoTracker® green and could be blocked using the known Translocator protein (TSPO)-inhibitor PK11195. This method supported the visualization and subsequent quantitative analysis of the migration patterns of individual non-GMO Pf sporozoites in human skin and did not affect the fitness of sporozoites. Conclusions: The ability to label and image non-GMO Plasmodium sporozoites provides the basis for detailed studies on the human skin stage of malaria with potential for in vivo translation. As such, it is an important tool for development of vaccines based on attenuated sporozoites and their route of administration.
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Affiliation(s)
- Béatrice M.F. Winkel
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Clarize M. de Korne
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Matthias N. van Oosterom
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Diego Staphorst
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Anton Bunschoten
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Laboratory of BioNanoTechnology Wageningen University and Research, Droevendaalsesteeg 4, 6708 PB Wageningen, The Netherlands
| | - Marijke C.C. Langenberg
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | | | - Chris J. Janse
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Blandine Franke-Fayard
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Fijs W.B. van Leeuwen
- Interventional Molecular Imaging laboratory, Department of Radiology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Meta Roestenberg
- Department of Parasitology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
- Department of Infectious Diseases, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
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Antkowiak B, Rammes G. GABA(A) receptor-targeted drug development -New perspectives in perioperative anesthesia. Expert Opin Drug Discov 2019; 14:683-699. [DOI: 10.1080/17460441.2019.1599356] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Bernd Antkowiak
- Department of Anesthesiology and Intensive Care, Experimental Anesthesiology Section, Eberhard-Karls-University,
Tübingen, Germany
- Department of Anaesthesiology and Intensive Care, Experimental Anaesthesiology Section, Werner Reichardt Center for Integrative Neuroscience, Tübingen,
Germany
| | - Gerhard Rammes
- University Hospital rechts der Isar, Department of Anesthesiology, München,
Germany
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Kapanadze T, Bankstahl JP, Wittneben A, Koestner W, Ballmaier M, Gamrekelashvili J, Krishnasamy K, Limbourg A, Ross TL, Meyer GJ, Haller H, Bengel FM, Limbourg FP. Multimodal and Multiscale Analysis Reveals Distinct Vascular, Metabolic and Inflammatory Components of the Tissue Response to Limb Ischemia. Am J Cancer Res 2019; 9:152-166. [PMID: 30662559 PMCID: PMC6332799 DOI: 10.7150/thno.27175] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 11/12/2018] [Indexed: 12/12/2022] Open
Abstract
Ischemia triggers a complex tissue response involving vascular, metabolic and inflammatory changes. Methods: We combined hybrid SPECT/CT or PET/CT nuclear imaging studies of perfusion, metabolism and inflammation with multicolor flow cytometry-based cell population analysis to comprehensively analyze the ischemic tissue response and to elucidate the cellular substrate of noninvasive molecular imaging techniques in a mouse model of hind limb ischemia. Results: Comparative analysis of tissue perfusion with [99mTc]-Sestamibi and arterial influx with [99mTc]-labeled albumin microspheres by SPECT/CT revealed a distinct pattern of response to vascular occlusion: an early ischemic period of matched suppression of tissue perfusion and arterial influx, a subacute ischemic period of normalized arterial influx but impaired tissue perfusion, and a protracted post-ischemic period of hyperdynamic arterial and normalized tissue perfusion, indicating coordination of macrovascular and microvascular responses. In addition, the subacute period showed increased glucose uptake by [18F]-FDG PET/CT scanning as the metabolic response of viable tissue to hypoperfusion. This was associated with robust macrophage infiltration by flow cytometry, and glucose uptake studies identified macrophages as major contributors to glucose utilization in ischemic tissue. Furthermore, imaging with the TSPO ligand [18F]-GE180 showed a peaked response during the subacute phase due to preferential labeling of monocytes and macrophages, while imaging with [68Ga]-RGD, an integrin ligand, showed prolonged post-ischemic upregulation, which was attributed to labeling of macrophages and endothelial cells by flow cytometry. Conclusion: Combined nuclear imaging and cell population analysis reveals distinct components of the ischemic tissue response and associated cell subsets, which could be targeted for therapeutic interventions.
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66
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Willson C. The clinical toxicology of caffeine: A review and case study. Toxicol Rep 2018; 5:1140-1152. [PMID: 30505695 PMCID: PMC6247400 DOI: 10.1016/j.toxrep.2018.11.002] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Revised: 10/09/2018] [Accepted: 11/01/2018] [Indexed: 02/08/2023] Open
Abstract
Caffeine is a widely recognized psychostimulant compound with a long history of consumption by humans. While it has received a significant amount of attention there is still much to be learned with respect to its toxicology in humans, especially in cases of overdose. A review of the history of consumption and the clinical toxicology of caffeine including clinical features, pharmacokinetics, toxicokinetics, a thorough examination of mechanism of action and management/treatment strategies are undertaken. While higher (i.e., several grams) quantities of caffeine are known to cause toxicity and potentially lethality, cases of mainly younger individuals who have experienced severe side effects and death despite consuming doses not otherwise known to cause such harm is troubling and deserves further study. An attempted case reconstruction is performed in an effort to shed light on this issue with a focus on the pharmacokinetics and pharmacodynamics of caffeine.
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67
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Tosh D, Ciancetta A, Mannes P, Warnick E, Janowsky A, Eshleman AJ, Gizewski E, Brust TF, Bohn LM, Auchampach JA, Gao ZG, Jacobson KA. Repurposing of a Nucleoside Scaffold from Adenosine Receptor Agonists to Opioid Receptor Antagonists. ACS OMEGA 2018; 3:12658-12678. [PMID: 30411015 PMCID: PMC6210068 DOI: 10.1021/acsomega.8b01237] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 09/19/2018] [Indexed: 06/08/2023]
Abstract
While screening off-target effects of rigid (N)-methanocarba-adenosine 5'-methylamides as A3 adenosine receptor (AR) agonists, we discovered μM binding hits at the δ-opioid receptor (DOR) and translocator protein (TSPO). In an effort to increase OR and decrease AR affinity by structure activity analysis of this series, antagonist activity at κ-(K)OR appeared in 5'-esters (ethyl 24 and propyl 30), which retained TSPO interaction (μM). 7-Deaza modification of C2-(arylethynyl)-5'-esters but not 4'-truncation enhanced KOR affinity (MRS7299 28 and 29, K i ≈ 40 nM), revealed μ-OR and DOR binding, and reduced AR affinity. Molecular docking and dynamics simulations located a putative KOR binding mode consistent with the observed affinities, placing C7 in a hydrophobic region. 3-Deaza modification permitted TSPO but not OR binding, and 1-deaza was permissive to both; ribose-restored analogues were inactive at both. Thus, we have repurposed a known AR nucleoside scaffold for OR antagonism, with a detailed hypothesis for KOR recognition.
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Affiliation(s)
- Dilip
K. Tosh
- Molecular
Recognition Section, Laboratory of Bioorganic Chemistry, National
Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Antonella Ciancetta
- Molecular
Recognition Section, Laboratory of Bioorganic Chemistry, National
Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Philip Mannes
- Molecular
Recognition Section, Laboratory of Bioorganic Chemistry, National
Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Eugene Warnick
- Molecular
Recognition Section, Laboratory of Bioorganic Chemistry, National
Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Aaron Janowsky
- VA
Portland Health Care System, Research Service (R&D-22), and Departments
of Psychiatry and Behavioral Neuroscience, Oregon Health and Science University, 3710 S.W. U.S. Veterans Hospital Blvd., Portland, Oregon 97239, United States
| | - Amy J. Eshleman
- VA
Portland Health Care System, Research Service (R&D-22), and Departments
of Psychiatry and Behavioral Neuroscience, Oregon Health and Science University, 3710 S.W. U.S. Veterans Hospital Blvd., Portland, Oregon 97239, United States
| | - Elizabeth Gizewski
- Department
of Pharmacology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Tarsis F. Brust
- Departments
of Molecular Medicine and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United
States
| | - Laura M. Bohn
- Departments
of Molecular Medicine and Neuroscience, The Scripps Research Institute, 130 Scripps Way, Jupiter, Florida 33458, United
States
| | - John A. Auchampach
- Department
of Pharmacology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226, United States
| | - Zhan-Guo Gao
- Molecular
Recognition Section, Laboratory of Bioorganic Chemistry, National
Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
| | - Kenneth A. Jacobson
- Molecular
Recognition Section, Laboratory of Bioorganic Chemistry, National
Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda, Maryland 20892, United States
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68
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Jurkiewicz P, Melser S, Maucourt M, Ayeb H, Veljanovski V, Maneta-Peyret L, Hooks M, Rolin D, Moreau P, Batoko H. The multistress-induced Translocator protein (TSPO) differentially modulates storage lipids metabolism in seeds and seedlings. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 96:274-286. [PMID: 30003614 DOI: 10.1111/tpj.14028] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 06/28/2018] [Accepted: 07/03/2018] [Indexed: 05/11/2023]
Abstract
Translocator proteins (TSPO) are conserved membrane proteins extensively studied in mammals, but their function is still unclear. Angiosperm TSPO are transiently induced by abiotic stresses in vegetative tissues. We showed previously that constitutive expression of the Arabidopsis TSPO (AtTSPO) could be detrimental to the cell. Degradation of AtTSPO requires an active autophagy pathway. We show here that genetic modifications of TSPO expression in plant and yeast cells reduce the levels of cytoplasmic lipid droplets (LD). Transgenic Arabidopsis seedlings overexpressing AtTSPO contain less LD as compared with wild type (WT). LD levels were increased in Arabidopsis AtTSPO knockout (KO) seedlings. Deletion of the Schizosaccharomyces pombe TSPO resulted in an increase in LD level in the cell. As compared with the WT, the mutant strain was more sensitive to cerulenin, an inhibitor of fatty acids and sterol biosynthesis. We found that in contrast with seedlings, overexpression of AtTSPO (OE) resulted in an up to 50% increase in seeds fatty acids as compared with WT. A time course experiment revealed that after 4 days of seed imbibition, the levels of triacylglycerol (TAG) was still higher in the OE seeds as compared with WT or KO seeds. However, the de novo synthesis of phospholipids and TAG after 24 h of imbibition was substantially reduced in OE seeds as compared with WT or KO seeds. Our findings support a plant TSPO role in energy homeostasis in a tissue-specific manner, enhancing fatty acids and LD accumulation in mature seeds and limiting LD levels in seedlings.
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Affiliation(s)
- Pawel Jurkiewicz
- Louvain Institute of Biomolecular Science and Technology (LIBST), UCLouvain, Croix du Sud 4-5, L7.07.14, 1348, Louvain-la-Neuve, Belgium
| | - Su Melser
- UMR 5200 Membrane Biogenesis Laboratory, CNRS-University of Bordeaux, INRA Bordeaux Aquitaine, 33140, Villenave d'Ornon, France
| | - Mickaël Maucourt
- Plateforme Métabolome Bordeaux, MetaboHUB, Bordeaux Functional Genomic Center, IBVM, CS 20032 F-33140, Villenave d'Ornon, France
| | - Haitham Ayeb
- Louvain Institute of Biomolecular Science and Technology (LIBST), UCLouvain, Croix du Sud 4-5, L7.07.14, 1348, Louvain-la-Neuve, Belgium
| | - Vasko Veljanovski
- Louvain Institute of Biomolecular Science and Technology (LIBST), UCLouvain, Croix du Sud 4-5, L7.07.14, 1348, Louvain-la-Neuve, Belgium
| | - Lilly Maneta-Peyret
- UMR 5200 Membrane Biogenesis Laboratory, CNRS-University of Bordeaux, INRA Bordeaux Aquitaine, 33140, Villenave d'Ornon, France
| | - Mark Hooks
- Plateforme Métabolome Bordeaux, MetaboHUB, Bordeaux Functional Genomic Center, IBVM, CS 20032 F-33140, Villenave d'Ornon, France
| | - Dominique Rolin
- Plateforme Métabolome Bordeaux, MetaboHUB, Bordeaux Functional Genomic Center, IBVM, CS 20032 F-33140, Villenave d'Ornon, France
| | - Patrick Moreau
- UMR 5200 Membrane Biogenesis Laboratory, CNRS-University of Bordeaux, INRA Bordeaux Aquitaine, 33140, Villenave d'Ornon, France
- Bordeaux Imaging Center, UMS 3420 CNRS, US4 INSERM, University of Bordeaux, 33000, Bordeaux, France
| | - Henri Batoko
- Louvain Institute of Biomolecular Science and Technology (LIBST), UCLouvain, Croix du Sud 4-5, L7.07.14, 1348, Louvain-la-Neuve, Belgium
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69
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Singh A, Kendall SL, Campanella M. Common Traits Spark the Mitophagy/Xenophagy Interplay. Front Physiol 2018; 9:1172. [PMID: 30294276 PMCID: PMC6158333 DOI: 10.3389/fphys.2018.01172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/03/2018] [Indexed: 12/16/2022] Open
Abstract
Selective autophagy contributes to the wellbeing of eukaryotic cells by recycling cellular components, disposing damaged organelles, and removing pathogens, amongst others. Both the quality control process of selective mitochondrial autophagy (Mitophagy) and the defensive process of intracellular pathogen-engulfment (Xenophagy) are facilitated via protein assemblies which have shared molecules, a prime example being the Tank-Binding Kinase 1 (TBK1). TBK1 plays a central role in the immunity response driven by Xenophagy and was recently shown to be an amplifying mechanism in Mitophagy, bring to attention the potential cross talk between the two processes. Here we draw parallels between Xenophagy and Mitophagy, speculating on the inhibitory mechanisms of specific proteins (e.g., the 18 kDa protein TSPO), how the preferential sequestering toward one of the two pathways may undermine the other, and in this way impair cellular response to pathogens and cellular immunity. We believe that an in depth understanding of the commonalities may present an opportunity to design novel therapeutic strategies targeted at both the autonomous and non-autonomous processes of selective autophagy.
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Affiliation(s)
- Aarti Singh
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom
| | - Sharon L Kendall
- Department of Pathology and Pathogen Biology, Royal Veterinary College, Hertfordshire, United Kingdom
| | - Michelangelo Campanella
- Department of Comparative Biomedical Sciences, Royal Veterinary College, London, United Kingdom.,UCL Consortium for Mitochondrial Research, London, United Kingdom
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Zeng J, Guareschi R, Damre M, Cao R, Kless A, Neumaier B, Bauer A, Giorgetti A, Carloni P, Rossetti G. Structural Prediction of the Dimeric Form of the Mammalian Translocator Membrane Protein TSPO: A Key Target for Brain Diagnostics. Int J Mol Sci 2018; 19:E2588. [PMID: 30200318 PMCID: PMC6165245 DOI: 10.3390/ijms19092588] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/21/2018] [Accepted: 08/28/2018] [Indexed: 11/17/2022] Open
Abstract
Positron emission tomography (PET) radioligands targeting the human translocator membrane protein (TSPO) are broadly used for the investigations of neuroinflammatory conditions associated with neurological disorders. Structural information on the mammalian protein homodimers-the suggested functional state of the protein-is limited to a solid-state nuclear magnetic resonance (NMR) study and to a model based on the previously-deposited solution NMR structure of the monomeric mouse protein. Computational studies performed here suggest that the NMR-solved structure in the presence of detergents is not prone to dimer formation and is furthermore unstable in its native membrane environment. We, therefore, propose a new model of the functionally-relevant dimeric form of the mouse protein, based on a prokaryotic homologue. The model, fully consistent with solid-state NMR data, is very different from the previous predictions. Hence, it provides, for the first time, structural insights into this pharmaceutically-important target which are fully consistent with experimental data.
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Affiliation(s)
- Juan Zeng
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
- Laboratory of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, 518055 Shenzhen, China.
| | - Riccardo Guareschi
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
| | - Mangesh Damre
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
- Neurobiology, International School for Advanced Studies (SISSA), 34136 Trieste, Italy.
| | - Ruyin Cao
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
| | - Achim Kless
- Grünenthal Innovation, Translational Science & Intelligence, Grünenthal GmbH, 52078 Aachen, Germany.
| | - Bernd Neumaier
- Institute for Neuroscience and Medicine (INM)-5, Forschungszentrum Jülich, 52428 Jülich, Germany.
| | - Andreas Bauer
- Institute for Neuroscience and Medicine (INM)-2, Forschungszentrum Jülich, 52428 Jülich, Germany.
| | - Alejandro Giorgetti
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134 Verona, Italy.
| | - Paolo Carloni
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
- RWTH Aachen University, Department of Physics, 52078 Aachen, Germany.
| | - Giulia Rossetti
- Institute for Advanced Simulations (IAS)-5/Institute for Neuroscience and Medicine (INM)-9, Forschungszentrum Jülich, 52428 Jülich, Germany.
- Jülich Supercomputing Center (JSC), Forschungszentrum Jülich, 52428 Jülich, Germany.
- University Hospital Aachen, RWTH Aachen University, 52078 Aachen, Germany.
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71
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Bhoola NH, Mbita Z, Hull R, Dlamini Z. Translocator Protein (TSPO) as a Potential Biomarker in Human Cancers. Int J Mol Sci 2018; 19:ijms19082176. [PMID: 30044440 PMCID: PMC6121633 DOI: 10.3390/ijms19082176] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 06/21/2018] [Accepted: 06/24/2018] [Indexed: 11/17/2022] Open
Abstract
TSPO is a receptor involved in the regulation of cellular proliferation, apoptosis and mitochondrial functions. Previous studies showed that the expression of TSPO protein correlated positively with tumour malignancy and negatively with patient survival. The aim of this study was to determine the transcription of Tspo mRNA in various types of normal and cancer tissues. In situ hybridization was performed to localise the Tspo mRNA in various human normal and cancer tissues. The relative level of Tspo mRNA was quantified using fluorescent intensity and visual estimation of colorimetric staining. RT-PCR was used to confirm these mRNA levels in normal lung, lung cancer, liver cancer, and cervical cancer cell lines. There was a significant increase in the level of transcription in liver, prostate, kidney, and brain cancers while a significant decrease was observed in cancers of the colon and lung. Quantitative RT-PCR confirmed that the mRNA levels of Tspo are higher in a normal lung cell line than in a lung cancer cell line. An increase in the expression levels of Tspo mRNA is not necessarily a good diagnostic biomarker in most cancers with changes not being large enough to be significantly different when detected by in situ hybridisation.
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Affiliation(s)
- Nimisha H Bhoola
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg 2193, South Africa.
| | - Zukile Mbita
- Department of Biochemistry, Microbiology and Biotechnology, University of Limpopo, Private Bag X1106, Sovenga 0727, South Africa.
| | - Rodney Hull
- Research, Innovation & Engagements Portfolio, Mangosuthu University of Technology, Durban 4031, South Africa.
| | - Zodwa Dlamini
- Research, Innovation & Engagements Portfolio, Mangosuthu University of Technology, Durban 4031, South Africa.
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72
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Expression and purification of the mammalian translocator protein for structural studies. PLoS One 2018; 13:e0198832. [PMID: 29897975 PMCID: PMC5999236 DOI: 10.1371/journal.pone.0198832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 05/26/2018] [Indexed: 11/19/2022] Open
Abstract
The translocator protein (TSPO) is an 18 kDa polytopic membrane protein of the outer mitochondrial membrane, abundantly present in the steroid-synthesising cells. TSPO has been linked to a number of disorders, and it is recognised as a promising drug target with a range of potential medical applications. Structural and biochemical characterisation of a mammalian TSPO requires expression and purification of the protein of high quality in sufficiently large quantities. Here we describe detailed procedures for heterologous expression and purification of mammalian TSPO in HEK293 cells. We demonstrate that the established procedures can be used for untagged TSPO as well as for C-terminally fused TSPO constructs. Our protocol can be routinely used to generate high-quality TSPO preparations for biochemical and structural studies.
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73
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Vignal N, Cisternino S, Rizzo-Padoin N, San C, Hontonnou F, Gelé T, Declèves X, Sarda-Mantel L, Hosten B. [ 18F]FEPPA a TSPO Radioligand: Optimized Radiosynthesis and Evaluation as a PET Radiotracer for Brain Inflammation in a Peripheral LPS-Injected Mouse Model. Molecules 2018; 23:molecules23061375. [PMID: 29875332 PMCID: PMC6099542 DOI: 10.3390/molecules23061375] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/25/2018] [Accepted: 06/04/2018] [Indexed: 01/17/2023] Open
Abstract
[18F]FEPPA is a specific ligand for the translocator protein of 18 kDa (TSPO) used as a positron emission tomography (PET) biomarker for glial activation and neuroinflammation. [18F]FEPPA radiosynthesis was optimized to assess in a mouse model the cerebral inflammation induced by an intraperitoneal injection of Salmonella enterica serovar Typhimurium lipopolysaccharides (LPS; 5 mg/kg) 24 h before PET imaging. [18F]FEPPA was synthesized by nucleophilic substitution (90 °C, 10 min) with tosylated precursor, followed by improved semi-preparative HPLC purification (retention time 14 min). [18F]FEPPA radiosynthesis were carried out in 55 min (from EOB). The non-decay corrected radiochemical yield were 34 ± 2% (n = 17), and the radiochemical purity greater than 99%, with a molar activity of 198 ± 125 GBq/µmol at the end of synthesis. Western blot analysis demonstrated a 2.2-fold increase in TSPO brain expression in the LPS treated mice compared to controls. This was consistent with the significant increase of [18F]FEPPA brain total volume of distribution (VT) estimated with pharmacokinetic modelling. In conclusion, [18F]FEPPA radiosynthesis was implemented with high yields. The new purification/formulation with only class 3 solvents is more suitable for in vivo studies.
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Affiliation(s)
- Nicolas Vignal
- Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Louis, Unité Claude Kellershohn, 75010 Paris, France.
- Inserm UMR-S 1144, Faculté de Pharmacie de Paris, Université Paris Descartes, 75006 Paris, France.
| | - Salvatore Cisternino
- Inserm UMR-S 1144, Faculté de Pharmacie de Paris, Université Paris Descartes, 75006 Paris, France.
- Assistance Publique-Hôpitaux de Paris, Hôpital Universitaire Necker-Enfants Malades, 75015 Paris, France.
| | - Nathalie Rizzo-Padoin
- Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Louis, Unité Claude Kellershohn, 75010 Paris, France.
- Inserm UMR-S 1144, Faculté de Pharmacie de Paris, Université Paris Descartes, 75006 Paris, France.
| | - Carine San
- Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Louis, Unité Claude Kellershohn, 75010 Paris, France.
| | - Fortune Hontonnou
- Institut Universitaire d'Hématologie, Université Paris Diderot, 75013 Paris, France.
| | - Thibaut Gelé
- Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Louis, Unité Claude Kellershohn, 75010 Paris, France.
| | - Xavier Declèves
- Inserm UMR-S 1144, Faculté de Pharmacie de Paris, Université Paris Descartes, 75006 Paris, France.
- Assistance Publique-Hôpitaux de Paris, Hôpital Cochin, 75014 Paris, France.
| | - Laure Sarda-Mantel
- Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Louis, Unité Claude Kellershohn, 75010 Paris, France.
- Assistance Publique-Hôpitaux de Paris, Hôpital Lariboisière, Médecine Nucléaire, 75010 Paris, France.
- Inserm UMR-S 942, Université Paris Diderot, 75013 Paris, France.
| | - Benoît Hosten
- Assistance Publique-Hôpitaux de Paris, Hôpital Saint-Louis, Unité Claude Kellershohn, 75010 Paris, France.
- Inserm UMR-S 1144, Faculté de Pharmacie de Paris, Université Paris Descartes, 75006 Paris, France.
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Lee YJ, Kim M, Lee JY, Jung SH, Jeon HY, Lee SA, Kang S, Han ET, Park WS, Hong SH, Kim YM, Ha KS. The benzodiazepine anesthetic midazolam prevents hyperglycemia-induced microvascular leakage in the retinas of diabetic mice. FASEB J 2018; 32:fj201800014RR. [PMID: 29782207 DOI: 10.1096/fj.201800014rr] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We investigated the beneficial effects of midazolam against vascular endothelial growth factor (VEGF)-induced vascular leakage and its molecular mechanism of action in human retinal endothelial cells (HRECs) and the retinas of diabetic mice. Midazolam inhibited VEGF-induced elevation of intracellular Ca2+, generation of reactive oxygen species (ROS), and transglutaminase activation in HRECs; these effects were reversed by the GABA, type A (GABAA) receptor antagonist flumazenil but not by the translocator protein antagonist PK11195. Midazolam also prevented VEGF-induced disassembly of adherens junctions and in vitro permeability. Intravitreal injection of midazolam prevented hyperglycemia-induced ROS generation, transglutaminase activation, and subsequent vascular leakage in the retinas of diabetic mice, and those effects were reversed by flumazenil. The roles of flumazenil were further supported by identifying GABAA receptors in mouse retinas. Thus, midazolam prevents hyperglycemia-induced vascular leakage by inhibiting VEGF-induced intracellular events in the retinas of diabetic mice.-Lee, Y.-J., Kim, M., Lee, J.-Y., Jung, S.-H., Jeon, H.-Y., Lee, S.-A., Kang, S., Han, E.-T., Park, W. S., Hong, S.-H., Kim, Y.-M., Ha, K.-S. The benzodiazepine anesthetic midazolam prevents hyperglycemia-induced microvascular leakage in the retinas of diabetic mice.
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Affiliation(s)
- Yeon-Ju Lee
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Minsoo Kim
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, Korea
- Department of Anesthesiology, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Jee-Yeon Lee
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Se-Hui Jung
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Hye-Yoon Jeon
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Seung Ah Lee
- Department of Anesthesiology, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Seongsik Kang
- Department of Anesthesiology, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Won Sun Park
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, Korea; and
| | - Seok-Ho Hong
- Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Young-Myeong Kim
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, Korea
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Translocator protein (18kDa TSPO) binding, a marker of microglia, is reduced in major depression during cognitive-behavioral therapy. Prog Neuropsychopharmacol Biol Psychiatry 2018; 83:1-7. [PMID: 29269262 DOI: 10.1016/j.pnpbp.2017.12.011] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 11/27/2017] [Accepted: 12/18/2017] [Indexed: 12/27/2022]
Abstract
Prior studies indicated that neuroinflammation might play a role in the pathophysiology of major depressive disorder (MDD). The purpose of this study was to examine changes in a microglial marker in the brain of patients with MDD during cognitive-behavioral therapy (CBT) and supportive psychotherapy (SPT). Participants were newly diagnosed patients with MDD receiving CBT (n=20) or SPT (n=20) who were compared with 20 healthy control subjects. We used [18F]-FEPPA positron emission tomography (PET) to examine translocator protein total distribution volume (TSPO VT), a marker of microglial density and inflammation. Patients were scanned before and after CBT and SPT. Before therapy, TSPO VT was significantly elevated in neocortical grey matter, frontal cortex, temporal cortex, and hippocampus in MDD relative to the control subjects. In the CBT group, but not in the SPT group, TSPO VT was significantly reduced during the treatment period. Reductions in TSPO VT were correlated with the amelioration of depressive symptoms. This correlation was consistent in the hippocampus in both CBT and SPT groups. In conclusion, CBT, when it reduced symptoms, also decreased TSPO VT. Efficient psychosocial interventions were accompanied by the normalization of a glial marker in the brain of patients with MDD, which may indicate reduced pro-inflammatory activity.
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76
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Biswas L, Zhou X, Dhillon B, Graham A, Shu X. Retinal pigment epithelium cholesterol efflux mediated by the 18 kDa translocator protein, TSPO, a potential target for treating age-related macular degeneration. Hum Mol Genet 2018; 26:4327-4339. [PMID: 28973423 DOI: 10.1093/hmg/ddx319] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 08/06/2017] [Indexed: 12/13/2022] Open
Abstract
Cholesterol accumulation beneath the retinal pigment epithelium (RPE) cells is supposed to contribute the pathogenesis of age-related macular degeneration (AMD). Cholesterol efflux genes (APOE and ABCA1) were identified as risk factors for AMD, although how cholesterol efflux influences accumulation of this lipid in sub-RPE deposits remains elusive. The 18 kDa translocator protein, TSPO, is a cholesterol-binding protein implicated in mitochondrial cholesterol transport. Here, we investigate the function of TSPO in cholesterol efflux from the RPE cells. We demonstrate in RPE cells that TSPO specific ligands promoted cholesterol efflux to acceptor (apo)lipoprotein and human serum, while loss of TSPO resulted in impaired cholesterol efflux. TSPO-/- RPE cells also had significantly increased production of reactive oxygen species (ROS) and upregulated expression of proinflammatory cytokines (IL-1β and TNFα). Cholesterol (oxidized LDL) uptake and accumulation were markedly increased in TSPO-/- RPE cells. Finally, in aged RPE cells, TSPO expression was reduced and cholesterol efflux impaired. These findings provide a new pharmacological concept to treat early AMD patients by stimulating cellular cholesterol removal with TSPO specific ligands or by overexpression of TSPO in RPE cells.
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Affiliation(s)
- Lincoln Biswas
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4?0BA, UK
| | - Xinzhi Zhou
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4?0BA, UK
| | - Baljean Dhillon
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16?4SB, UK
| | - Annette Graham
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4?0BA, UK
| | - Xinhua Shu
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4?0BA, UK
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77
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Chen YC, Wu KC, Huang BM, So EC, Wang YK. Midazolam inhibits chondrogenesis via peripheral benzodiazepine receptor in human mesenchymal stem cells. J Cell Mol Med 2018. [PMID: 29516686 PMCID: PMC5908119 DOI: 10.1111/jcmm.13584] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Midazolam, a benzodiazepine derivative, is widely used for sedation and surgery. However, previous studies have demonstrated that Midazolam is associated with increased risks of congenital malformations, such as dwarfism, when used during early pregnancy. Recent studies have also demonstrated that Midazolam suppresses osteogenesis of mesenchymal stem cells (MSCs). Given that hypertrophic chondrocytes can differentiate into osteoblast and osteocytes and contribute to endochondral bone formation, the effect of Midazolam on chondrogenesis remains unclear. In this study, we applied a human MSC line, the KP cell, to serve as an in vitro model to study the effect of Midazolam on chondrogenesis. We first successfully established an in vitro chondrogenic model in a micromass culture or a 2D high‐density culture performed with TGF‐β‐driven chondrogenic induction medium. Treatment of the Midazolam dose‐dependently inhibited chondrogenesis, examined using Alcian blue‐stained glycosaminoglycans and the expression of chondrogenic markers, such as SOX9 and type II collagen. Inhibition of Midazolam by peripheral benzodiazepine receptor (PBR) antagonist PK11195 or small interfering RNA rescued the inhibitory effects of Midazolam on chondrogenesis. In addition, Midazolam suppressed transforming growth factor‐β‐induced Smad3 phosphorylation, and this inhibitory effect could be rescued using PBR antagonist PK11195. This study provides a possible explanation for Midazolam‐induced congenital malformations of the musculoskeletal system through PBR.
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Affiliation(s)
- Yung-Ching Chen
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - King-Chuen Wu
- Department of Nursing, Chang Gung University of Science and Technology, Chia-Yi County, Taiwan.,Department of Anesthesiology, Chang Gung Memorial Hospital, Chiayi County, Taiwan
| | - Bu-Miin Huang
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Edmund Cheung So
- Department of Anesthesiology, An-Nan Hospital, China Medical University, Tainan, Taiwan.,Department of Medicine, China Medical University, Taichung, Taiwan
| | - Yang-Kao Wang
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan, Taiwan
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78
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Prossin AR, Chandler M, Ryan KA, Saunders EF, Kamali M, Papadopoulos V, Zöllner S, Dantzer R, McInnis MG. Functional TSPO polymorphism predicts variance in the diurnal cortisol rhythm in bipolar disorder. Psychoneuroendocrinology 2018; 89:194-202. [PMID: 29414032 PMCID: PMC6048960 DOI: 10.1016/j.psyneuen.2018.01.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 01/11/2018] [Accepted: 01/17/2018] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Psychosocial stress contributes to onset/exacerbation of mood episodes and alcohol use, suggesting dysregulated diurnal cortisol rhythms underlie episodic exacerbations in Bipolar Disorder (BD). However, mechanisms underlying dysregulated HPA rhythms in BD and alcohol use disorders (AUD) are understudied. Knowledge of associated variance factors have great clinical translational potential by facilitating development of strategies to reduce stress-related relapse in BD and AUD. Evidence suggests structural changes to mitochondrial translocator protein (TSPO) (a regulator of steroid synthesis) due to the single nucleotide polymorphism rs6971, may explain much of this variance. However, whether rs6971 is associated with abnormal HPA rhythms and clinical exacerbation in humans is unknown. METHODS To show this common TSPO polymorphism impacts HPA rhythms in BD, we tested whether rs6971 (dichotomized: presence/absence of polymorphism) predicted variance in diurnal cortisol rhythm (saliva: morning and evening for 3 days) in 107 BD (50 with and 57 without AUD) and 28 healthy volunteers of similar age and ethno-demographic distribution. RESULTS Repeated measures ANOVA confirmed effects BD (F5,525 = 3.0, p = 0.010) and AUD (F5,525 = 2.9, p = 0.012), but not TSPO polymorphism (p > 0.05). Interactions were confirmed for TSPO × BD (F5,525 = 3.9, p = 0.002) and for TSPO × AUD (F5,525 = 2.8, p = 0.017). DISCUSSION We identified differences in diurnal cortisol rhythm depending on presence/absence of common TSPO polymorphism in BD volunteers with or without AUD and healthy volunteers. These results have wide ranging implications but further validation is needed prior to optimal clinical translation.
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Affiliation(s)
- Alan R Prossin
- Department of Psychiatry, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA; Houston Methodist Research Institute, Houston, TX, USA.
| | - Matthew Chandler
- Department of Psychiatry, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Kelly A Ryan
- Department of Psychiatry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Erika F Saunders
- Department of Psychiatry, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Psychiatry, Medical School, Penn State College of Medicine and the Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Masoud Kamali
- Department of Psychiatry, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | | | - Sebastian Zöllner
- Department of Psychiatry, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Robert Dantzer
- Department of Symptom Research, Division of Internal Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Melvin G McInnis
- Department of Psychiatry, University of Michigan Medical School, Ann Arbor, MI, USA
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79
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Papadopoulos V, Fan J, Zirkin B. Translocator protein (18 kDa): an update on its function in steroidogenesis. J Neuroendocrinol 2018; 30:10.1111/jne.12500. [PMID: 28667781 PMCID: PMC5748373 DOI: 10.1111/jne.12500] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 12/15/2022]
Abstract
Translocator protein (18 kDa) (TSPO) is a ubiquitous mitochondrial protein. Studies of its responses to drug and endogenous ligands have shown TSPO to be involved either directly or indirectly in numerous biological functions, including mitochondrial cholesterol transport and steroid hormone biosynthesis, porphyrin transport and heme synthesis, apoptosis, cell proliferation, and anion transport. Localised to the outer mitochondrial membrane of steroidogenic cells, TSPO has been shown to associate with cytosolic and mitochondrial proteins as part of a large multiprotein complex involved in mitochondrial cholesterol transport, the rate-limiting step in steroidogenesis. There is general agreement as to the structure and pharmacology of TSPO. Stimulation of TSPO has been shown to have therapeutic use as anxiolytics by inducing allopregnanolone production in the brain, and also potentially for re-establishing androgen levels in hypogonadal ageing animals. Until recently, there has been general agreement regarding the role of TSPO in steroidogenesis. However, recent studies involving genetic depletion of TSPO in mice have created controversy about the role of this protein in steroid and heme synthesis. We review the data on the structure and function of TSPO, as well as the recent results obtained using various genetic animal models. Taken together, these studies suggest that TSPO is a unique mitochondrial pharmacological target for diseases that involve increased mitochondrial activity, including steroidogenesis. Although there is no known mammalian species that lacks TSPO, it is likely that, because of the importance of this ancient protein in evolution and mitochondrial function, redundant mechanisms may exist to replace it under circumstances when it is removed.
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Affiliation(s)
- Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089
- Research Institute of the McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Jinjiang Fan
- Research Institute of the McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Barry Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
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80
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Waters L, Manchester KR, Maskell PD, Haegeman C, Haider S. The use of a quantitative structure-activity relationship (QSAR) model to predict GABA-A receptor binding of newly emerging benzodiazepines. Sci Justice 2017; 58:219-225. [PMID: 29685303 DOI: 10.1016/j.scijus.2017.12.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/13/2017] [Accepted: 12/16/2017] [Indexed: 02/06/2023]
Abstract
The illicit market for new psychoactive substances is forever expanding. Benzodiazepines and their derivatives are one of a number of groups of these substances and thus far their number has grown year upon year. For both forensic and clinical purposes it is important to be able to rapidly understand these emerging substances. However as a consequence of the illicit nature of these compounds, there is a deficiency in the pharmacological data available for these 'new' benzodiazepines. In order to further understand the pharmacology of 'new' benzodiazepines we utilised a quantitative structure-activity relationship (QSAR) approach. A set of 69 benzodiazepine-based compounds was analysed to develop a QSAR training set with respect to published binding values to GABAA receptors. The QSAR model returned an R2 value of 0.90. The most influential factors were found to be the positioning of two H-bond acceptors, two aromatic rings and a hydrophobic group. A test set of nine random compounds was then selected for internal validation to determine the predictive ability of the model and gave an R2 value of 0.86 when comparing the binding values with their experimental data. The QSAR model was then used to predict the binding for 22 benzodiazepines that are classed as new psychoactive substances. This model will allow rapid prediction of the binding activity of emerging benzodiazepines in a rapid and economic way, compared with lengthy and expensive in vitro/in vivo analysis. This will enable forensic chemists and toxicologists to better understand both recently developed compounds and prediction of substances likely to emerge in the future.
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Affiliation(s)
- Laura Waters
- School of Applied Sciences, University of Huddersfield, Huddersfield, UK.
| | | | - Peter D Maskell
- School of Science, Engineering and Technology, Abertay University, Dundee, UK
| | | | - Shozeb Haider
- School of Pharmacy, University College London, London, UK
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81
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Regulation of Mitochondrial, Cellular, and Organismal Functions by TSPO. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 82:103-136. [PMID: 29413517 DOI: 10.1016/bs.apha.2017.09.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In 1999, the enigma of the 18kDa mitochondrial translocator protein (TSPO), also known as the peripheral-type benzodiazepine receptor, was the seeming disparity of the many functions attributed to TSPO, ranging from the potential of TSPO acting as a housekeeping gene at molecular biological levels to adaptations to stress, and even involvement in higher emotional and cognitive functioning, such as anxiety and depression. In the years since then, knowledge regarding the many functions modulated by TSPO has expanded, and understanding has deepened. In addition, new functions could be firmly associated with TSPO, such as regulation of programmed cell death and modulation of gene expression. Interestingly, control by the mitochondrial TSPO over both of these life and death functions appears to include Ca++ homeostasis, generation of reactive oxygen species (ROS), and ATP production. Other mitochondrial functions under TSPO control are considered to be steroidogenesis and tetrapyrrole metabolism. As TSPO effects on gene expression and on programmed cell death can be related to the wide range of functions that can be associated with TSPO, several of these five elements of Ca++, ROS, ATP, steroids, and tetrapyrroles may indeed form the basis of TSPO's capability to operate as a multifunctional housekeeping gene to maintain homeostasis of the cell and of the whole multicellular organism.
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82
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Chen K, Wang L, Yang W, Wang C, Hu G, Mo Z. Profiling of differentially expressed genes in adipose tissues of multiple symmetric lipomatosis. Mol Med Rep 2017; 16:6570-6579. [PMID: 28901441 PMCID: PMC5865826 DOI: 10.3892/mmr.2017.7437] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 07/04/2017] [Indexed: 12/15/2022] Open
Abstract
Multiple symmetric lipomatosis (MSL) is a rare disorder characterized by aberrant multiple and symmetric subcutaneous adipose tissue accumulation in the face, neck, shoulders, back, chest and abdomen, severely affecting the quality of life of patients. At present, precise MSL etiology and pathogenesis remain to be elucidated. The present study first utilized a digital gene expression technique with a next‑generation sequencing platform to profile differentially expressed genes in three cases of MSL vs. normal control tissue. cDNA libraries from these tissue specimens were constructed and DNA sequenced for identification of differentially expressed genes, which underwent bioinformatic analysis using the Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein‑protein interaction (PPI) network analyses. As a result, a total of 859 differentially expressed genes were identified, including 308 upregulated genes (C19orf80, Apelin, C21orf33, FAM166B and HSD11B2 were mostly upregulated 6.984‑, 4.670‑, 4.412‑, 3.693‑ and 3.561‑fold, respectively) and 551 downregulated genes [FosB proto‑oncogene, AP‑1 transcription factor subunit (FOSB), selectin (SEL) E, RAR related orphan receptor (ROR) B, salt inducible kinase (SIK)1 and epidermal growth factor‑like protein (EGFL)6 were mostly downregulated ‑9.845, ‑8.243, ‑8.123, ‑7.702 and ‑7.664 fold, respectively). The GO functional enrichment analysis demonstrated these differentially expressed genes were predominantly involved in biological processes and cellular components, while the KEGG pathway enrichment analysis demonstrated that ribosome, non‑alcoholic fatty liver disease, human T‑lymphotropic virus type 1 (HTLV‑I) infection and Alzheimer's disease pathways were altered in MSL. The PPI network data demonstrated ubiquitin C (UBC), translocator protein (TSPO), Jun Proto‑Oncogene, AP‑1 Transcription Factor (JUN) and FOS were among these differentially expressed genes that participated in regulation of adipocyte differentiation, although no previous study has linked them to MSL. In conclusion, the present study profiled differentially expressed genes in MSL and identified gene pathways that may be associated with MSL development and progression.
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Affiliation(s)
- Ke Chen
- Department of Endocrinology, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
| | - Linghao Wang
- Department of Endocrinology, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
| | - Wenjun Yang
- Department of Endocrinology, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
| | - Changfa Wang
- Department of General Surgery, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
| | - Gui Hu
- Department of General Surgery, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
| | - Zhaohui Mo
- Department of Endocrinology, The Third Xiangya Hospital of Central South University, Changsha, Hunan 410013, P.R. China
- Correspondence to: Professor Zhaohui Mo, Department of Endocrinology, The Third Xiangya Hospital of Central South University, 138 Tong Zi Po Road, Changsha, Hunan 410013, P.R. China, E-mail:
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83
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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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84
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TSPO PET Imaging: From Microglial Activation to Peripheral Sterile Inflammatory Diseases? CONTRAST MEDIA & MOLECULAR IMAGING 2017; 2017:6592139. [PMID: 29114179 PMCID: PMC5632884 DOI: 10.1155/2017/6592139] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 08/01/2017] [Accepted: 08/07/2017] [Indexed: 02/07/2023]
Abstract
Peripheral sterile inflammatory diseases (PSIDs) are a heterogeneous group of disorders that gathers several chronic insults involving the cardiovascular, respiratory, gastrointestinal, or musculoskeletal system and wherein inflammation is the cornerstone of the pathophysiology. In PSID, timely characterization and localization of inflammatory foci are crucial for an adequate care for patients. In brain diseases, in vivo positron emission tomography (PET) exploration of inflammation has matured over the last 20 years, through the development of radiopharmaceuticals targeting the translocator protein-18 kDa (TSPO) as molecular biomarkers of activated microglia. Recently, TSPO has been introduced as a possible molecular target for PSIDs PET imaging, making this protein a potential biomarker to address disease heterogeneity, to assist in patient stratification, and to contribute to predicting treatment response. In this review, we summarized the major research advances recently made in the field of TSPO PET imaging in PSIDs. Promising preliminary results have been reported in bowel, cardiovascular, and rheumatic inflammatory diseases, consolidated by preclinical studies. Limitations of TSPO PET imaging in PSIDs, regarding both its large expression in healthy peripheral tissues, unlike in central nervous system, and the production of peripheral radiolabeled metabolites, are also discussed, regarding their possible consequences on TSPO PET signal's quantification.
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85
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Milite C, Barresi E, Da Pozzo E, Costa B, Viviano M, Porta A, Messere A, Sbardella G, Da Settimo F, Novellino E, Cosconati S, Castellano S, Taliani S, Martini C. Exploiting the 4-Phenylquinazoline Scaffold for the Development of High Affinity Fluorescent Probes for the Translocator Protein (TSPO). J Med Chem 2017; 60:7897-7909. [DOI: 10.1021/acs.jmedchem.7b01031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Ciro Milite
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
| | - Elisabetta Barresi
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Eleonora Da Pozzo
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Barbara Costa
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Monica Viviano
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
| | - Amalia Porta
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
| | - Anna Messere
- DiSTABiF, University of Campania Luigi Vanvitelli, 81100 Caserta, Italy
| | - Gianluca Sbardella
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
| | - Federico Da Settimo
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Ettore Novellino
- Dipartimento
di Farmacia, Università di Napoli “Federico II”, Via D. Montesano 49, 80131 Napoli, Italy
| | - Sandro Cosconati
- DiSTABiF, University of Campania Luigi Vanvitelli, 81100 Caserta, Italy
| | - Sabrina Castellano
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
- Dipartimento
di Medicina, Chirurgia e Odontoiatria “Scuola Medica Salernitana”, Università di Salerno, Via Salvador Allende, I-84081 Baronissi, Salerno, Italy
| | - Sabrina Taliani
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Claudia Martini
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
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86
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Owen DR, Narayan N, Wells L, Healy L, Smyth E, Rabiner EA, Galloway D, Williams JB, Lehr J, Mandhair H, Peferoen LA, Taylor PC, Amor S, Antel JP, Matthews PM, Moore CS. Pro-inflammatory activation of primary microglia and macrophages increases 18 kDa translocator protein expression in rodents but not humans. J Cereb Blood Flow Metab 2017; 37:2679-2690. [PMID: 28530125 PMCID: PMC5536262 DOI: 10.1177/0271678x17710182] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The 18kDa Translocator Protein (TSPO) is the most commonly used tissue-specific marker of inflammation in positron emission tomography (PET) studies. It is expressed in myeloid cells such as microglia and macrophages, and in rodent myeloid cells expression increases with cellular activation. We assessed the effect of myeloid cell activation on TSPO gene expression in both primary human and rodent microglia and macrophages in vitro, and also measured TSPO radioligand binding with 3H-PBR28 in primary human macrophages. As observed previously, we found that TSPO expression increases (∼9-fold) in rodent-derived macrophages and microglia upon pro-inflammatory stimulation. However, TSPO expression does not increase with classical pro-inflammatory activation in primary human microglia (fold change 0.85 [95% CI 0.58-1.12], p = 0.47). In contrast, pro-inflammatory activation of human monocyte-derived macrophages is associated with a reduction of both TSPO gene expression (fold change 0.60 [95% CI 0.45-0.74], p = 0.02) and TSPO binding site abundance (fold change 0.61 [95% CI 0.49-0.73], p < 0.0001). These findings have important implications for understanding the biology of TSPO in activated macrophages and microglia in humans. They are also clinically relevant for the interpretation of PET studies using TSPO targeting radioligands, as they suggest changes in TSPO expression may reflect microglial and macrophage density rather than activation phenotype.
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Affiliation(s)
- David R Owen
- 1 Division of Brain Sciences, Department of Medicine Hammersmith Hospital, Imperial College London, London, UK
| | - Nehal Narayan
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Lisa Wells
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK
| | - Luke Healy
- 4 Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Erica Smyth
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK
| | - Eugenii A Rabiner
- 3 Imanova Centre for Imaging Science, Hammersmith Hospital, London, UK.,5 Centre for Neuroimaging Sciences, King's College, London, UK
| | - Dylan Galloway
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - John B Williams
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - Joshua Lehr
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
| | - Harpreet Mandhair
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Laura An Peferoen
- 7 Pathology Department, VU Medical Centre, VU University of Amsterdam, The Netherlands
| | - Peter C Taylor
- 2 Nuffield Department of Orthopaedics, Rheumatology & Musculoskeletal Sciences, Botnar Research Centre, University of Oxford, Oxford, UK
| | - Sandra Amor
- 7 Pathology Department, VU Medical Centre, VU University of Amsterdam, The Netherlands.,8 Neuroimmunology Unit, Blizard Institute, Barts and the London School of medicine & Dentistry Queen Mary University of London, UK
| | - Jack P Antel
- 4 Neuroimmunology Unit, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Paul M Matthews
- 1 Division of Brain Sciences, Department of Medicine Hammersmith Hospital, Imperial College London, London, UK.,9 UK Dementia Research Institute, Imperial College London, London, UK
| | - Craig S Moore
- 6 Division of Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland
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87
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Classical and Novel TSPO Ligands for the Mitochondrial TSPO Can Modulate Nuclear Gene Expression: Implications for Mitochondrial Retrograde Signaling. Int J Mol Sci 2017; 18:ijms18040786. [PMID: 28387723 PMCID: PMC5412370 DOI: 10.3390/ijms18040786] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2017] [Revised: 03/24/2017] [Accepted: 03/27/2017] [Indexed: 12/22/2022] Open
Abstract
It is known that knockdown of the mitochondrial 18 kDa translocator protein (TSPO) as well as TSPO ligands modulate various functions, including functions related to cancer. To study the ability of TSPO to regulate gene expression regarding such functions, we applied microarray analysis of gene expression to U118MG glioblastoma cells. Within 15 min, the classical TSPO ligand PK 11195 induced changes in expression of immediate early genes and transcription factors. These changes also included gene products that are part of the canonical pathway serving to modulate general gene expression. These changes are in accord with real-time, reverse transcriptase (RT) PCR. At the time points of 15, 30, 45, and 60 min, as well as 3 and 24 h of PK 11195 exposure, the functions associated with the changes in gene expression in these glioblastoma cells covered well known TSPO functions. These functions included cell viability, proliferation, differentiation, adhesion, migration, tumorigenesis, and angiogenesis. This was corroborated microscopically for cell migration, cell accumulation, adhesion, and neuronal differentiation. Changes in gene expression at 24 h of PK 11195 exposure were related to downregulation of tumorigenesis and upregulation of programmed cell death. In the vehicle treated as well as PK 11195 exposed cell cultures, our triple labeling showed intense TSPO labeling in the mitochondria but no TSPO signal in the cell nuclei. Thus, mitochondrial TSPO appears to be part of the mitochondria-to-nucleus signaling pathway for modulation of nuclear gene expression. The novel TSPO ligand 2-Cl-MGV-1 appeared to be very specific regarding modulation of gene expression of immediate early genes and transcription factors.
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88
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Dupont AC, Largeau B, Santiago Ribeiro MJ, Guilloteau D, Tronel C, Arlicot N. Translocator Protein-18 kDa (TSPO) Positron Emission Tomography (PET) Imaging and Its Clinical Impact in Neurodegenerative Diseases. Int J Mol Sci 2017; 18:ijms18040785. [PMID: 28387722 PMCID: PMC5412369 DOI: 10.3390/ijms18040785] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/31/2017] [Accepted: 04/04/2017] [Indexed: 02/06/2023] Open
Abstract
In vivo exploration of activated microglia in neurodegenerative diseases is achievable by Positron Emission Tomography (PET) imaging, using dedicated radiopharmaceuticals targeting the translocator protein-18 kDa (TSPO). In this review, we emphasized the major advances made over the last 20 years, thanks to TSPO PET imaging, to define the pathophysiological implication of microglia activation and neuroinflammation in neurodegenerative diseases, including Parkinson’s disease, Huntington’s disease, dementia, amyotrophic lateral sclerosis, multiple sclerosis, and also in psychiatric disorders. The extent and upregulation of TSPO as a molecular biomarker of activated microglia in the human brain is now widely documented in these pathologies, but its significance, and especially its protective or deleterious action regarding the disease’s stage, remains under debate. Thus, we exposed new and plausible suggestions to enhance the contribution of TSPO PET imaging for biomedical research by exploring microglia’s role and interactions with other cells in brain parenchyma. Multiplex approaches, associating TSPO PET radiopharmaceuticals with other biomarkers (PET imaging of cellular metabolism, neurotransmission or abnormal protein aggregates, but also other imaging modalities, and peripheral cytokine levels measurement and/or metabolomics analysis) was considered. Finally, the actual clinical impact of TSPO PET imaging as a routine biomarker of neuroinflammation was put into perspective regarding the current development of diagnostic and therapeutic strategies for neurodegenerative diseases.
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Affiliation(s)
- Anne-Claire Dupont
- CHRU Tours, 2 Boulevard Tonnellé, 37044 Tours, France.
- Institut National de la Santé et de la Recherche Médicale U930, 10 Boulevard Tonnellé, 37032 Tours, France.
| | | | - Maria Joao Santiago Ribeiro
- CHRU Tours, 2 Boulevard Tonnellé, 37044 Tours, France.
- Institut National de la Santé et de la Recherche Médicale U930, 10 Boulevard Tonnellé, 37032 Tours, France.
| | - Denis Guilloteau
- CHRU Tours, 2 Boulevard Tonnellé, 37044 Tours, France.
- Institut National de la Santé et de la Recherche Médicale U930, 10 Boulevard Tonnellé, 37032 Tours, France.
| | - Claire Tronel
- Institut National de la Santé et de la Recherche Médicale U930, 10 Boulevard Tonnellé, 37032 Tours, France.
| | - Nicolas Arlicot
- CHRU Tours, 2 Boulevard Tonnellé, 37044 Tours, France.
- Institut National de la Santé et de la Recherche Médicale U930, 10 Boulevard Tonnellé, 37032 Tours, France.
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89
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Isokpehi RD, Simmons SS, Johnson MO, Payton M. Genomic Evidence for Bacterial Determinants Influencing Obesity Development. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14040345. [PMID: 28346358 PMCID: PMC5409546 DOI: 10.3390/ijerph14040345] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 03/09/2017] [Accepted: 03/14/2017] [Indexed: 12/11/2022]
Abstract
Obesity is a major global public health problem requiring multifaceted interventional approaches including dietary interventions with probiotic bacteria. High-throughput genome sequencing of microbial communities in the mammalian gastrointestinal system continues to present diverse protein function information to understand the bacterial determinants that influence obesity development. The goal of the research reported in this article was to identify biological processes in probiotic bacteria that could influence the mechanisms for the extraction of energy from diet in the human gastrointestinal system. Our research strategy of combining bioinformatics and visual analytics methods was based on the identification of operon gene arrangements in genomes of Lactobacillus species and Akkermansiamuciniphila that include at least a gene for a universal stress protein. The two major findings from this research study are related to Lactobacillus plantarum and Akkermansia muciniphila bacteria species which are associated with weight-loss. The first finding is that Lactobacillus plantarum strains have a two-gene operon that encodes a universal stress protein for stress response and the membrane translocator protein (TSPO), known to function in mitochondrial fatty acid oxidation in humans. The second finding is the presence of a three-gene operon in Akkermansia muciniphila that includes a gene whose human mitochondrial homolog is associated with waist-hip ratio and fat distribution. From a public health perspective, elucidation of the bacterial determinants influencing obesity will help in educating the public on optimal probiotic use for anti-obesity effects.
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Affiliation(s)
- Raphael D Isokpehi
- College of Science, Engineering and Mathematics, Bethune-Cookman University, Daytona Beach, FL 32114, USA.
| | - Shaneka S Simmons
- Division of Arts and Sciences, Jarvis Christian College, Hawkins, TX 75765, USA.
- Center of Excellence in Minority Health and Health Disparities, Jackson State University, Jackson, MS 39217, USA.
| | - Matilda O Johnson
- Petrock College of Health Sciences, Bethune-Cookman University, Daytona Beach, FL 32114, USA.
| | - Marinelle Payton
- Center of Excellence in Minority Health and Health Disparities, Jackson State University, Jackson, MS 39217, USA.
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90
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Busch AWU, Montgomery BL. Distinct light-, stress-, and nutrient-dependent regulation of multiple tryptophan-rich sensory protein (TSPO) genes in the cyanobacterium Fremyella diplosiphon. PLANT SIGNALING & BEHAVIOR 2017; 12:e1293221. [PMID: 28277971 PMCID: PMC5399897 DOI: 10.1080/15592324.2017.1293221] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 01/30/2017] [Accepted: 02/04/2017] [Indexed: 06/06/2023]
Abstract
The cyanobacterium Fremyella diplosiphon possesses 3 genes encoding homologs of the tryptophan-rich sensory protein (TSPO). TSPO proteins are membrane proteins implicated in stress responses across a range of organisms from bacteria to humans. Diverse TSPO proteins appear to generally bind tetrapyrrole ligands. Previously, we reported that one of these homologs, FdTSPO1, is involved in salt-, osmotic- and oxidative stress responses in F. diplosiphon. Here, we show distinct regulation of cellular mRNA levels of all 3 FdTSPO homologs by different abiotic stresses. Given the prior finding that all 3 FdTSPO proteins are capable of binding tetrapyrroles of functional relevance in F. diplosiphon and the observation of a ligand-dependent functional role for FdTSPO1 in vivo, FdTSPO1, FdTSPO2, and FdTSPO3 appear to have distinct, yet overlapping, roles in vivo. We propose that these proteins regulate tetrapyrrole homeostasis and/or tetrapyrrole-modulated functions in F. diplosiphon in response to multiple environmental stresses.
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Affiliation(s)
- Andrea W. U. Busch
- Department of Energy — Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Beronda L. Montgomery
- Department of Energy — Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
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91
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Scott G, Mahmud M, Owen DR, Johnson MR. Microglial positron emission tomography (PET) imaging in epilepsy: Applications, opportunities and pitfalls. Seizure 2017; 44:42-47. [DOI: 10.1016/j.seizure.2016.10.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 10/27/2016] [Indexed: 10/20/2022] Open
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92
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Busch AWU, WareJoncas Z, Montgomery BL. Tryptophan-Rich Sensory Protein/Translocator Protein (TSPO) from Cyanobacterium Fremyella diplosiphon Binds a Broad Range of Functionally Relevant Tetrapyrroles. Biochemistry 2016; 56:73-84. [PMID: 27990801 DOI: 10.1021/acs.biochem.6b01019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Tryptophan-rich sensory protein/translocator protein (TSPO) is a membrane protein involved in stress adaptation in the cyanobacterium Fremyella diplosiphon. Characterized mammalian and proteobacterial TSPO homologues bind tetrapyrroles and cholesterol ligands. We investigated the ligand binding properties of TSPO from F. diplosiphon (FdTSPO1), which was functionally characterized in prior genetic studies. Two additional TSPO proteins (FdTSPO2 and FdTSPO3) are present in F. diplosiphon; they are similar in size to reported bacterial TSPOs and smaller than FdTSPO1. The longer cyanobacterial TSPO1 is found almost exclusively in filamentous cyanobacteria and has a relatively low degree of homology to bacterial and mammalian TSPO homologues with confirmed tetrapyrrole binding. To probe distinctions of long-form TSPOs, we tested the binding of porphyrin and bilin to FdTSPO1 and measured binding affinities in the low micromolar range, with the highest binding affinity detected for heme. Although tetrapyrrole ligands bound FdTSPO1 with affinities similar to those previously reported for proteobacterial TSPO, binding of cholesterol to FdTSPO1 was particularly poor and was not improved by introducing an amino acid motif known to enhance cholesterol binding in other bacterial TSPO homologues. Additionally, we detected limited binding of bacterial hopanoids to FdTSPO1. Cyanobacterial TSPO1 from the oxygenic photosynthetic F. diplosiphon, thus, binds a range of tetrapyrroles of functional relevance with efficiencies similar to those of mammalian and proteobacterial homologues, but the level of cholesterol binding is greatly reduced compared to that of mammalian TSPO. Furthermore, the ΔFdTSPO1 mutant exhibits altered growth in the presence of biliverdin compared to that of wild-type cells under green light. Together, these results suggest that TSPO molecules may play roles in bilin homeostasis or trafficking in cyanobacteria.
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Affiliation(s)
- Andrea W U Busch
- Plant Research Laboratory, Department of Energy, Michigan State University , East Lansing, Michigan 48824, United States
| | - Zachary WareJoncas
- Plant Research Laboratory, Department of Energy, Michigan State University , East Lansing, Michigan 48824, United States
| | - Beronda L Montgomery
- Plant Research Laboratory, Department of Energy, Michigan State University , East Lansing, Michigan 48824, United States.,Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States.,Department of Microbiology & Molecular Genetics, Michigan State University , East Lansing, Michigan 48824, United States
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93
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Guo CH, Bai L, Wu HH, Yang J, Cai GH, Zeng SX, Wang X, Wu SX, Ma W. Midazolam and ropivacaine act synergistically to inhibit bone cancer pain with different mechanisms in rats. Oncol Rep 2016; 37:249-258. [PMID: 27841001 DOI: 10.3892/or.2016.5241] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 10/24/2016] [Indexed: 11/06/2022] Open
Abstract
Analgesic strategy of a single drug analgesia in bone cancer pain (BCP) has shifted to combined analgesia with different drugs which have different mechanism. After tumor cell inculation, the activation of signal transducer and activator of transcription (STAT3) and extracellular signal-regulated kinase (ERK) signaling pathway are involved in the development and maintenance of BCP, whereas a decrease in the expression of spinal STAT3 and ERK through using their specific blocker, lead to attenuation of BCP. Hence, in this study, we clarified that intrathecal (i.t.) injection of midazolam (MZL) and ropivacaine (Ropi) induces synergistic analgesia on BCP and is accompanied with different mechanisms of these analgesic effect. Hargreaves heat test was used to detect the analgesic effect of single dose of i.t. MZL, Ropi and their combination on the BCP rats. At consecutive daily administration experiment, thermal hyperalgesia was recorded, and immunohistochemical staining was used to detect the expression of c-Fos, spinal glial fibrillary acidic protein (GFAP) and ionized calcium binding adapter molecule-1 (IBA-1). Then, western blot analysis was used to examine spinal TSPO, GFAP, IBA-1, pERK/ERK and pSTAT3/STAT3 levels on day 14 after tumor cell inoculation. i.t. MZL or Ropi showed a short-term analgesia dose-dependently, and MZL displayed better effect on inhibition of pSTAT3 expression than pERK, but Ropi was just the reverse, then consecutive daily administrations of their combination acted synergistically to attenuate thermal hyperalgesia with downregulated spinal 'neuron-astrocytic activation' in the BCP rats. i.t. co-delivery of MZL and Ropi shows synergistic analgesia on the BCP with the inhibition of spinal 'neuron-astrocytic activation'. Spinal different signaling pathway inhibition for MZL and Ropi may be involved in this process.
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Affiliation(s)
- Chi-Hua Guo
- Department of Orthopedics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Lu Bai
- Department of Medical Imaging, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Huang-Hui Wu
- Department of Anesthesiology, Fuzhou General Hospital of Nanjing Military Region, Fuzhou, Fujian 350025, P.R. China
| | - Jing Yang
- Institute of Neuroscience, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, P.R. China
| | - Guo-Hong Cai
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Si-Xiang Zeng
- Department of Orthopedics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
| | - Xin Wang
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Sheng-Xi Wu
- Department of Neurobiology and Collaborative Innovation Center for Brain Science, Fourth Military Medical University, Xi'an, Shaanxi 710032, P.R. China
| | - Wei Ma
- Department of Orthopedics, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, P.R. China
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