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Bréhat J, Leick S, Musman J, Su JB, Eychenne N, Giton F, Rivard M, Barel LA, Tropeano C, Vitarelli F, Caccia C, Leoni V, Ghaleh B, Pons S, Morin D. Identification of a mechanism promoting mitochondrial sterol accumulation during myocardial ischemia-reperfusion: role of TSPO and STAR. Basic Res Cardiol 2024; 119:481-503. [PMID: 38517482 DOI: 10.1007/s00395-024-01043-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 02/16/2024] [Accepted: 02/19/2024] [Indexed: 03/24/2024]
Abstract
Hypercholesterolemia is a major risk factor for coronary artery diseases and cardiac ischemic events. Cholesterol per se could also have negative effects on the myocardium, independently from hypercholesterolemia. Previously, we reported that myocardial ischemia-reperfusion induces a deleterious build-up of mitochondrial cholesterol and oxysterols, which is potentiated by hypercholesterolemia and prevented by translocator protein (TSPO) ligands. Here, we studied the mechanism by which sterols accumulate in cardiac mitochondria and promote mitochondrial dysfunction. We performed myocardial ischemia-reperfusion in rats to evaluate mitochondrial function, TSPO, and steroidogenic acute regulatory protein (STAR) levels and the related mitochondrial concentrations of sterols. Rats were treated with the cholesterol synthesis inhibitor pravastatin or the TSPO ligand 4'-chlorodiazepam. We used Tspo deleted rats, which were phenotypically characterized. Inhibition of cholesterol synthesis reduced mitochondrial sterol accumulation and protected mitochondria during myocardial ischemia-reperfusion. We found that cardiac mitochondrial sterol accumulation is the consequence of enhanced influx of cholesterol and not of the inhibition of its mitochondrial metabolism during ischemia-reperfusion. Mitochondrial cholesterol accumulation at reperfusion was related to an increase in mitochondrial STAR but not to changes in TSPO levels. 4'-Chlorodiazepam inhibited this mechanism and prevented mitochondrial sterol accumulation and mitochondrial ischemia-reperfusion injury, underlying the close cooperation between STAR and TSPO. Conversely, Tspo deletion, which did not alter cardiac phenotype, abolished the effects of 4'-chlorodiazepam. This study reveals a novel mitochondrial interaction between TSPO and STAR to promote cholesterol and deleterious sterol mitochondrial accumulation during myocardial ischemia-reperfusion. This interaction regulates mitochondrial homeostasis and plays a key role during mitochondrial injury.
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Affiliation(s)
- Juliette Bréhat
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Faculté de Santé, 8 rue du général Sarrail, 94000, Créteil, France
| | - Shirin Leick
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Faculté de Santé, 8 rue du général Sarrail, 94000, Créteil, France
| | - Julien Musman
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Faculté de Santé, 8 rue du général Sarrail, 94000, Créteil, France
| | - Jin Bo Su
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Faculté de Santé, 8 rue du général Sarrail, 94000, Créteil, France
| | | | - Frank Giton
- Pôle Biologie-Pathologie, IMRB U955, Hôpital Henri Mondor, Créteil, France
| | | | | | - Chiara Tropeano
- Laboratory of Clinical Chemistry, ASST-Brianza Department of Medicine and Surgery, Hospital Pio XI Desio, University of Milano Bicocca, Monza, Italy
| | - Frederica Vitarelli
- Laboratory of Clinical Chemistry, ASST-Brianza Department of Medicine and Surgery, Hospital Pio XI Desio, University of Milano Bicocca, Monza, Italy
| | - Claudio Caccia
- Unit of Medical Genetics and Neurogenetics, Istituto Neurologico Carlo Besta, Fondazione IRCCS, Milan, Italy
| | - Valerio Leoni
- Laboratory of Clinical Chemistry, ASST-Brianza Department of Medicine and Surgery, Hospital Pio XI Desio, University of Milano Bicocca, Monza, Italy
| | - Bijan Ghaleh
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Faculté de Santé, 8 rue du général Sarrail, 94000, Créteil, France
| | - Sandrine Pons
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Faculté de Santé, 8 rue du général Sarrail, 94000, Créteil, France
| | - Didier Morin
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Faculté de Santé, 8 rue du général Sarrail, 94000, Créteil, France.
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Yu M, Zhao S. Functional role of translocator protein and its ligands in ocular diseases (Review). Mol Med Rep 2024; 29:33. [PMID: 38186312 PMCID: PMC10804439 DOI: 10.3892/mmr.2024.13157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 12/08/2023] [Indexed: 01/09/2024] Open
Abstract
The 18 kDa translocator protein (TSPO) is an essential outer mitochondrial membrane protein that is responsible for mitochondrial transport, maintenance of mitochondrial homeostasis and normal physiological cell function. The role of TSPO in the pathogenesis of ocular diseases is a growing area of interest. More notably, TSPO exerts positive effects in regulating various pathophysiological processes, such as the inflammatory response, oxidative stress, steroid synthesis and modulation of microglial function, in combination with a variety of specific ligands such as 1‑(2‑chlorophenyl‑N‑methylpropyl)‑3‑isoquinolinecarboxamide, 4'‑chlorodiazepam and XBD173. In the present review, the expression of TSPO in ocular tissues and the functional role of TSPO and its ligands in diverse ocular diseases was discussed.
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Affiliation(s)
- Mingyi Yu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 30384, P.R. China
| | - Shaozhen Zhao
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 30384, P.R. China
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Baglini E, Poggetti V, Cavallini C, Petroni D, Forini F, Nicolini G, Barresi E, Salerno S, Costa B, Iozzo P, Neglia D, Menichetti L, Taliani S, Da Settimo F. Targeting the Translocator Protein (18 kDa) in Cardiac Diseases: State of the Art and Future Opportunities. J Med Chem 2024; 67:17-37. [PMID: 38113353 PMCID: PMC10911791 DOI: 10.1021/acs.jmedchem.3c01716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/16/2023] [Accepted: 11/24/2023] [Indexed: 12/21/2023]
Abstract
Mitochondria dysfunctions are typical hallmarks of cardiac disorders (CDs). The multiple tasks of this energy-producing organelle are well documented, but its pathophysiologic involvement in several manifestations of heart diseases, such as altered electromechanical coupling, excitability, and arrhythmias, is still under investigation. The human 18 kDa translocator protein (TSPO) is a protein located on the outer mitochondrial membrane whose expression is altered in different pathological conditions, including CDs, making it an attractive therapeutic and diagnostic target. Currently, only a few TSPO ligands are employed in CDs and cardiac imaging. In this Perspective, we report an overview of the emerging role of TSPO at the heart level, focusing on the recent literature concerning the development of TSPO ligands used for fighting and imaging heart-related disease conditions. Accordingly, targeting TSPO might represent a successful strategy to achieve novel therapeutic and diagnostic strategies to unravel the fundamental mechanisms and to provide solutions to still unanswered questions in CDs.
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Affiliation(s)
- Emma Baglini
- Institute
of Clinical Physiology, National Research Council of Italy, CNR Research Area, Via G. Moruzzi 1, Pisa 56124, Italy
| | - Valeria Poggetti
- Department
of Pharmacy, University of Pisa, Via Bonanno 6, Pisa 56126, Italy
| | - Chiara Cavallini
- Institute
of Clinical Physiology, National Research Council of Italy, CNR Research Area, Via G. Moruzzi 1, Pisa 56124, Italy
| | - Debora Petroni
- Institute
of Clinical Physiology, National Research Council of Italy, CNR Research Area, Via G. Moruzzi 1, Pisa 56124, Italy
| | - Francesca Forini
- Institute
of Clinical Physiology, National Research Council of Italy, CNR Research Area, Via G. Moruzzi 1, Pisa 56124, Italy
| | - Giuseppina Nicolini
- Institute
of Clinical Physiology, National Research Council of Italy, CNR Research Area, Via G. Moruzzi 1, Pisa 56124, Italy
| | - Elisabetta Barresi
- Department
of Pharmacy, University of Pisa, Via Bonanno 6, Pisa 56126, Italy
| | - Silvia Salerno
- Department
of Pharmacy, University of Pisa, Via Bonanno 6, Pisa 56126, Italy
| | - Barbara Costa
- Department
of Pharmacy, University of Pisa, Via Bonanno 6, Pisa 56126, Italy
| | - Patricia Iozzo
- Institute
of Clinical Physiology, National Research Council of Italy, CNR Research Area, Via G. Moruzzi 1, Pisa 56124, Italy
| | - Danilo Neglia
- Fondazione
CNR/Regione Toscana Gabriele Monasterio, Cardiovascular and Imaging
Departments, CNR Research Area, Via G. Moruzzi 1, Pisa 56124, Italy
| | - Luca Menichetti
- Institute
of Clinical Physiology, National Research Council of Italy, CNR Research Area, Via G. Moruzzi 1, Pisa 56124, Italy
| | - Sabrina Taliani
- Department
of Pharmacy, University of Pisa, Via Bonanno 6, Pisa 56126, Italy
| | - Federico Da Settimo
- Department
of Pharmacy, University of Pisa, Via Bonanno 6, Pisa 56126, Italy
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18F-Radiolabeled Translocator Protein (TSPO) PET Tracers: Recent Development of TSPO Radioligands and Their Application to PET Study. Pharmaceutics 2022; 14:pharmaceutics14112545. [PMID: 36432736 PMCID: PMC9697781 DOI: 10.3390/pharmaceutics14112545] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/16/2022] [Accepted: 11/17/2022] [Indexed: 11/23/2022] Open
Abstract
Translocator protein 18 kDa (TSPO) is a transmembrane protein in the mitochondrial membrane, which has been identified as a peripheral benzodiazepine receptor. TSPO is generally present at high concentrations in steroid-producing cells and plays an important role in steroid synthesis, apoptosis, and cell proliferation. In the central nervous system, TSPO expression is relatively modest under normal physiological circumstances. However, some pathological disorders can lead to changes in TSPO expression. Overexpression of TSPO is associated with several diseases, such as neurodegenerative diseases, neuroinflammation, brain injury, and cancers. TSPO has therefore become an effective biomarker of related diseases. Positron emission tomography (PET), a non-invasive molecular imaging technique used for the clinical diagnosis of numerous diseases, can detect diseases related to TSPO expression. Several radiolabeled TSPO ligands have been developed for PET. In this review, we describe recent advances in the development of TSPO ligands, and 18F-radiolabeled TSPO in particular, as PET tracers. This review covers pharmacokinetic studies, preclinical and clinical trials of 18F-labeled TSPO PET ligands, and the synthesis of TSPO ligands.
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Salazar-Ramírez F, Ramos-Mondragón R, García-Rivas G. Mitochondrial and Sarcoplasmic Reticulum Interconnection in Cardiac Arrhythmia. Front Cell Dev Biol 2021; 8:623381. [PMID: 33585462 PMCID: PMC7876262 DOI: 10.3389/fcell.2020.623381] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 12/30/2020] [Indexed: 12/31/2022] Open
Abstract
Ca2+ plays a pivotal role in mitochondrial energy production, contraction, and apoptosis. Mitochondrial Ca2+-targeted fluorescent probes have demonstrated that mitochondria Ca2+ transients are synchronized with Ca2+ fluxes occurring in the sarcoplasmic reticulum (SR). The presence of specialized proteins tethering SR to mitochondria ensures the local Ca2+ flux between these organelles. Furthermore, communication between SR and mitochondria impacts their functionality in a bidirectional manner. Mitochondrial Ca2+ uptake through the mitochondrial Ca2+ uniplex is essential for ATP production and controlled reactive oxygen species levels for proper cellular signaling. Conversely, mitochondrial ATP ensures the proper functioning of SR Ca2+-handling proteins, which ensures that mitochondria receive an adequate supply of Ca2+. Recent evidence suggests that altered SR Ca2+ proteins, such as ryanodine receptors and the sarco/endoplasmic reticulum Ca2+ ATPase pump, play an important role in maintaining proper cardiac membrane excitability, which may be initiated and potentiated when mitochondria are dysfunctional. This recognized mitochondrial role offers the opportunity to develop new therapeutic approaches aimed at preventing cardiac arrhythmias in cardiac disease.
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Affiliation(s)
- Felipe Salazar-Ramírez
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Cardiovascular, Monterrey, Mexico
| | - Roberto Ramos-Mondragón
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, United States.,Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
| | - Gerardo García-Rivas
- Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Cátedra de Cardiología y Medicina Cardiovascular, Monterrey, Mexico.,TecSalud, Centro de Investigación Biomédica, Hospital Zambrano-Hellion, San Pedro Garza García, Mexico.,TecSalud, Centro de Medicina Funcional, Hospital Zambrano-Hellion, San Pedro Garza García, Mexico
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Adameova A, Shah AK, Dhalla NS. Role of Oxidative Stress in the Genesis of Ventricular Arrhythmias. Int J Mol Sci 2020; 21:E4200. [PMID: 32545595 PMCID: PMC7349053 DOI: 10.3390/ijms21124200] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/05/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022] Open
Abstract
Ventricular arrhythmias, mainly lethal arrhythmias, such as ventricular tachycardia and fibrillation, may lead to sudden cardiac death. These are triggered as a result of cardiac injury due to chronic ischemia, acute myocardial infarction and various stressful conditions associated with increased levels of circulating catecholamines and angiotensin II. Several mechanisms have been proposed to underlie electrical instability of the heart promoting ventricular arrhythmias; however, oxidative stress which adversely affects ion homeostasis due to changes in the ion channel structure and function, seems to play a critical role in eliciting different types of ventricular arrhythmias. Prevention or mitigation of the severity of ventricular arrhythmias due to antioxidants has been indicated as the fundamental contribution in the field of preventive cardiology; however, novel interventions have to be developed for greater effectiveness and specificity in attenuating the adverse effects of oxidative stress. In this review, we have attempted to discuss proarrhythmic effects of oxidative stress differing in time and concentration dependence and highlight a molecular and cellular concept how it alters cardiac cell automaticity and conduction velocity sensitizing the probability of ventricular arrhythmias with resultant sudden cardiac death due to ischemic heart disease and other stressful situations. It is concluded that pharmacological approaches targeting multiple mechanisms besides oxidative stress might be more effective in the treatment of ventricular arrhythmias than current antiarrhythmic therapy.
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Affiliation(s)
- Adriana Adameova
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, and Center of Experimental Medicine, Slovak Academy of Sciences, Institute for Heart Research, Odbojarov 10, 83232 Bratislava, Slovakia
| | - Anureet K. Shah
- Department of Kinesiology, Nutrition and Food Science, California State University, Los Angeles, CA 90032, USA;
| | - Naranjan S. Dhalla
- Institute of Cardiovascular Sciences, St. Boniface Hospital Albrechtsen Research Centre, and Department of Physiology & Pathophysiology, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB R3E 0W2, Canada;
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7
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Da Pozzo E, Tremolanti C, Costa B, Giacomelli C, Milenkovic VM, Bader S, Wetzel CH, Rupprecht R, Taliani S, Da Settimo F, Martini C. Microglial Pro-Inflammatory and Anti-Inflammatory Phenotypes Are Modulated by Translocator Protein Activation. Int J Mol Sci 2019; 20:ijms20184467. [PMID: 31510070 PMCID: PMC6770267 DOI: 10.3390/ijms20184467] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/06/2019] [Accepted: 09/09/2019] [Indexed: 12/13/2022] Open
Abstract
A key role of the mitochondrial Translocator Protein 18 KDa (TSPO) in neuroinflammation has been recently proposed. However, little is known about TSPO-activated pathways underlying the modulation of reactive microglia. In the present work, the TSPO activation was explored in an in vitro human primary microglia model (immortalized C20 cells) under inflammatory stimulus. Two different approaches were used with the aim to (i) pharmacologically amplify or (ii) silence, by the lentiviral short hairpin RNA, the TSPO physiological function. In the TSPO pharmacological stimulation model, the synthetic steroidogenic selective ligand XBD-173 attenuated the activation of microglia. Indeed, it reduces and increases the release of pro-inflammatory and anti-inflammatory cytokines, respectively. Such ligand-induced effects were abolished when C20 cells were treated with the steroidogenesis inhibitor aminoglutethimide. This suggests a role for neurosteroids in modulating the interleukin production. The highly steroidogenic ligand XBD-173 attenuated the neuroinflammatory response more effectively than the poorly steroidogenic ones, which suggests that the observed modulation on the cytokine release may be influenced by the levels of produced neurosteroids. In the TSPO silencing model, the reduction of TSPO caused a more inflamed phenotype with respect to scrambled cells. Similarly, during the inflammatory response, the TSPO silencing increased and reduced the release of pro-inflammatory and anti-inflammatory cytokines, respectively. In conclusion, the obtained results are in favor of a homeostatic role for TSPO in the context of dynamic balance between anti-inflammatory and pro-inflammatory mediators in the human microglia-mediated inflammatory response. Interestingly, our preliminary results propose that the TSPO expression could be stimulated by NF-κB during activation of the inflammatory response.
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Affiliation(s)
- Eleonora Da Pozzo
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (E.D.P.); (C.T.); (C.G.); (S.T.); (F.D.S.); (C.M.)
| | - Chiara Tremolanti
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (E.D.P.); (C.T.); (C.G.); (S.T.); (F.D.S.); (C.M.)
| | - Barbara Costa
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (E.D.P.); (C.T.); (C.G.); (S.T.); (F.D.S.); (C.M.)
- Correspondence:
| | - Chiara Giacomelli
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (E.D.P.); (C.T.); (C.G.); (S.T.); (F.D.S.); (C.M.)
| | - Vladimir M. Milenkovic
- Department of Psychiatry and Psychotherapy, Molecular Neurosciences, University of Regensburg, 93059 Regensburg, Germany; (V.M.M.); (S.B.); (C.H.W.); (R.R.)
| | - Stefanie Bader
- Department of Psychiatry and Psychotherapy, Molecular Neurosciences, University of Regensburg, 93059 Regensburg, Germany; (V.M.M.); (S.B.); (C.H.W.); (R.R.)
| | - Christian H. Wetzel
- Department of Psychiatry and Psychotherapy, Molecular Neurosciences, University of Regensburg, 93059 Regensburg, Germany; (V.M.M.); (S.B.); (C.H.W.); (R.R.)
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, Molecular Neurosciences, University of Regensburg, 93059 Regensburg, Germany; (V.M.M.); (S.B.); (C.H.W.); (R.R.)
| | - Sabrina Taliani
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (E.D.P.); (C.T.); (C.G.); (S.T.); (F.D.S.); (C.M.)
| | - Federico Da Settimo
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (E.D.P.); (C.T.); (C.G.); (S.T.); (F.D.S.); (C.M.)
| | - Claudia Martini
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy; (E.D.P.); (C.T.); (C.G.); (S.T.); (F.D.S.); (C.M.)
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TSPO Ligands Promote Cholesterol Efflux and Suppress Oxidative Stress and Inflammation in Choroidal Endothelial Cells. Int J Mol Sci 2018; 19:ijms19123740. [PMID: 30477223 PMCID: PMC6321017 DOI: 10.3390/ijms19123740] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/16/2018] [Accepted: 11/21/2018] [Indexed: 02/06/2023] Open
Abstract
Choroidal endothelial cells supply oxygen and nutrients to retinal pigment epithelial (RPE) cells and photoreceptors, recycle metabolites, and dispose of metabolic waste through the choroidal blood circulation. Death of the endothelial cells of the choroid may cause abnormal deposits including unesterified and esterified cholesterol beneath RPE cells and within Bruch’s membrane that contribute to the progression of age-related macular degeneration (AMD), the most prevalent cause of blindness in older people. Translocator protein (TSPO) is a cholesterol-binding protein that is involved in mitochondrial cholesterol transport and other cellular functions. We have investigated the role of TSPO in choroidal endothelial cells. Immunocytochemistry showed that TSPO was localized to the mitochondria of choroidal endothelial cells. Choroidal endothelial cells exposed to TSPO ligands (Etifoxine or XBD-173) had significantly increased cholesterol efflux, higher expression of cholesterol homeostasis genes (LXRα, CYP27A1, CYP46A1, ABCA1 and ABCG1), and reduced biosynthesis of cholesterol and phospholipids from [14C]acetate, when compared to untreated controls. Treatment with TSPO ligands also resulted in reduced production of reactive oxygen species (ROS), increased antioxidant capacity, and reduced release of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and VEGF) induced by oxidized LDL. These data suggest TSPO ligands may offer promise for the treatment of AMD.
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Oyama Y, Bartman CM, Gile J, Sehrt D, Eckle T. The Circadian PER2 Enhancer Nobiletin Reverses the Deleterious Effects of Midazolam in Myocardial Ischemia and Reperfusion Injury. Curr Pharm Des 2018; 24:3376-3383. [PMID: 30246635 PMCID: PMC6318050 DOI: 10.2174/1381612824666180924102530] [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] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/10/2018] [Accepted: 09/16/2018] [Indexed: 01/01/2023]
Abstract
BACKGROUND Recently, we identified the circadian rhythm protein Period 2 (PER2) in robust cardioprotection from myocardial ischemia (MI). Based on findings that perioperative MI is the most common major cardiovascular complication and that anesthetics can alter the expression of PER2, we hypothesized that an anesthesia mediated downregulation of PER2 could be detrimental if myocardial ischemia and reperfusion (IR) would occur. METHODS AND RESULTS We exposed mice to pentobarbital, fentanyl, ketamine, propofol, midazolam or isoflurane and determined cardiac Per2 mRNA levels. Unexpectedly, only midazolam treatment resulted in an immediate and significant downregulation of Per2 transcript levels. Subsequent studies in mice pretreated with midazolam using an in-situ mouse model for myocardial (IR)-injury revealed a significant and dramatic increase in infarct sizes or Troponin-I serum levels in the midazolam treated group when compared to controls. Using the recently identified flavonoid, nobiletin, as a PER2 enhancer completely abolished the deleterious effects of midazolam during myocardial IR-injury. Moreover, nobiletin treatment alone significantly reduced infarct sizes or Troponin I levels in wildtype but not in Per2-/- mice. Pharmacological studies on nobiletin like flavonoids revealed that only nobiletin and tangeritin, both found to enhance PER2, were cardioprotective in our murine model for myocardial IR-injury. CONCLUSION We identified midazolam mediated downregulation of cardiac PER2 as an underlying mechanism for a deleterious effect of midazolam pretreatment in myocardial IR-injury. These findings highlight PER2 as a cardioprotective mechanism and suggest the PER2 enhancers nobiletin or tangeritin as a preventative therapy for myocardial IR-injury in the perioperative setting where midazolam pretreatment occurs frequently.
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Affiliation(s)
- Yoshimasa Oyama
- Department of Anesthesiology, University of Colorado Denver School of Medicine, Aurora, CO 80045, United States
| | - Colleen Marie Bartman
- Department of Anesthesiology, University of Colorado Denver School of Medicine, Aurora, CO 80045, United States
| | - Jennifer Gile
- Department of Anesthesiology, University of Colorado Denver School of Medicine, Aurora, CO 80045, United States
| | - Daniel Sehrt
- Department of Anesthesiology, University of Colorado Denver School of Medicine, Aurora, CO 80045, United States
| | - Tobias Eckle
- Department of Anesthesiology, University of Colorado Denver School of Medicine, Aurora, CO 80045, United States
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Silachev DN, Usatikova EA, Pevzner IB, Zorova LD, Babenko VA, Gulyaev MV, Pirogov YA, Plotnikov EY, Zorov DB. Effect of Anesthetics on Efficiency of Remote Ischemic Preconditioning. BIOCHEMISTRY (MOSCOW) 2017; 82:1006-1016. [PMID: 28988529 DOI: 10.1134/s0006297917090036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Remote ischemic preconditioning of hind limbs (RIPC) is an effective method for preventing brain injury resulting from ischemia. However, in numerous studies RIPC has been used on the background of administered anesthetics, which also could exhibit neuroprotective properties. Therefore, investigation of the signaling pathways triggered by RIPC and the effect of anesthetics is important. In this study, we explored the effect of anesthetics (chloral hydrate and Zoletil) on the ability of RIPC to protect the brain from injury caused by ischemia and reperfusion. We found that RIPC without anesthesia resulted in statistically significant decrease in neurological deficit 24 h after ischemia, but did not affect the volume of brain injury. Administration of chloral hydrate or Zoletil one day prior to brain ischemia produced a preconditioning effect by their own, decreasing the degree of neurological deficit and lowering the volume of infarct with the use of Zoletil. The protective effects observed after RIPC with chloral hydrate or Zoletil were similar to those observed when only the respective anesthetic was used. RIPC was accompanied by significant increase in the level of brain proteins associated with the induction of ischemic tolerance such as pGSK-3β, BDNF, and HSP70. However, Zoletil did not affect the level of these proteins 24 h after injection, and chloral hydrate caused increase of only pGSK-3β. We conclude that RIPC, chloral hydrate, and Zoletil produce a significant neuroprotective effect, but the simultaneous use of anesthetics with RIPC does not enhance the degree of neuroprotection.
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Affiliation(s)
- D N Silachev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119992, Russia.
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Gambardella J, Sorriento D, Ciccarelli M, Del Giudice C, Fiordelisi A, Napolitano L, Trimarco B, Iaccarino G, Santulli G. Functional Role of Mitochondria in Arrhythmogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 982:191-202. [PMID: 28551788 DOI: 10.1007/978-3-319-55330-6_10] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Growing evidence indicate that mitochondria play a functional role in arrhythmogenesis. We report here the molecular mechanisms underlying the action of these highly dynamic organelles in the regulation of cell metabolism, action potential and, overall, heart excitability. In particular, we examine the role of cardiac mitochondria in linking metabolism and cell excitability. The importance of the main mitochondrial channels is evaluated as well, including the recently identified calcium uniporter. Promises and pitfalls of potential therapeutic strategies targeting mitochondrial pathways are also assessed.
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Affiliation(s)
- Jessica Gambardella
- Columbia University Medical Center, New York, NY, USA.,Department of Medicine, Surgery and Dentistry, University of Salerno, Baronissi, Italy
| | - Daniela Sorriento
- Department of Advanced Biomedical Sciences, "Federico II" University, Naples, Italy
| | - Michele Ciccarelli
- Department of Medicine, Surgery and Dentistry, University of Salerno, Baronissi, Italy
| | - Carmine Del Giudice
- Department of Advanced Biomedical Sciences, "Federico II" University, Naples, Italy
| | - Antonella Fiordelisi
- Department of Advanced Biomedical Sciences, "Federico II" University, Naples, Italy
| | - Luigi Napolitano
- Department of Advanced Biomedical Sciences, "Federico II" University, Naples, Italy
| | - Bruno Trimarco
- Department of Advanced Biomedical Sciences, "Federico II" University, Naples, Italy
| | - Guido Iaccarino
- Department of Medicine, Surgery and Dentistry, University of Salerno, Baronissi, Italy
| | - Gaetano Santulli
- Dept. of Biomedical Advanced Sciences, Federico II University, Naples, Italy. .,Columbia University Medical Center, New York Presbyterian Hospital-Manhattan, New York, NY, USA.
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12
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Iacobazzi RM, Lopalco A, Cutrignelli A, Laquintana V, Lopedota A, Franco M, Denora N. Bridging Pharmaceutical Chemistry with Drug and Nanoparticle Targeting to Investigate the Role of the 18-kDa Translocator Protein TSPO. ChemMedChem 2017; 12:1261-1274. [PMID: 28771957 DOI: 10.1002/cmdc.201700322] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Revised: 07/06/2017] [Indexed: 11/10/2022]
Abstract
An interesting mitochondrial biomarker is the 18-kDa mitochondrial translocator protein (TSPO). Decades of study have shown that this protein plays an important role in a wide range of cellular functions, including opening of the mitochondrial permeability transition pore as well as programmed cell death and proliferation. Variations in TSPO expression have been correlated to different diseases, from tumors to endocrine and neurological disorders. TSPO has therefore become an appealing target for both early diagnosis and selective mitochondrial drug delivery. The number of structurally different TSPO ligands examined has increased over time, highlighting the scientific community's growing understanding of the roles of TSPO in normal and pathological conditions. However, only few TSPO ligands are characterized by the presence of groups that are potentially derivatizable; therefore only few such ligands are well suited for the preparation of targeted prodrugs or nanocarriers able to deliver therapeutics and/or diagnostic agents to mitochondria. This review provides an overview of the very few examples of drug delivery systems characterized by moieties that target TSPO.
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Affiliation(s)
| | - Antonio Lopalco
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Annalisa Cutrignelli
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Valentino Laquintana
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Angela Lopedota
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Massimo Franco
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
| | - Nunzio Denora
- Dipartimento di Farmacia-Scienze del Farmaco, Università degli Studi di Bari Aldo Moro, Via Orabona 4, 70125, Bari, Italy
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Kim T, Pae AN. Translocator protein (TSPO) ligands for the diagnosis or treatment of neurodegenerative diseases: a patent review (2010 – 2015; part 2). Expert Opin Ther Pat 2016; 26:1353-1366. [DOI: 10.1080/13543776.2016.1230605] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- TaeHun Kim
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology, Seoul, Republic of Korea
- Biological Chemistry, Korea University of Science and Technology, Daejon, Republic of Korea
| | - Ae Nim Pae
- Convergence Research Center for Diagnosis, Treatment and Care System of Dementia, Korea Institute of Science and Technology, Seoul, Republic of Korea
- Biological Chemistry, Korea University of Science and Technology, Daejon, Republic of Korea
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15
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Cardioprotective effects of intracoronary administration of 4-chlorodiazepam in small and large animal models of ischemia-reperfusion. Int J Cardiol 2016; 224:90-95. [PMID: 27643472 DOI: 10.1016/j.ijcard.2016.09.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/31/2016] [Accepted: 09/08/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND The Translocator Protein (TSPO) of the mitochondrial membrane has been recognized as a potential therapeutic target for mitigation of myocardial ischemia-reperfusion injury. Administration of 4-chlorodiazepam (4-CLD), a TSPO ligand, has been shown to confer acute cardioprotective effects in small animals; however, long-term studies and studies in clinically-relevant large animal models are lacking. In the present study we investigated a potential cardioprotective effect of intracoronary administration of 4-CLD in small and large animal models of ischemia-reperfusion. METHODS Acute myocardial infarction was induced in 38 Wistar rats and 29 farm pigs by ligation of the left anterior descending coronary artery, followed by reperfusion. Animals were randomized to undergo intracoronary infusion of 2μM 4-CLD or vehicle just prior (pigs) or immediately after (rats) reperfusion. Infarcted rats were euthanized either after 1h of reperfusion (for histological assessment of the "no reflow" area) or after 60days (for serial evaluation of cardiac function and structure by echocardiography and assessment of infarct size). Infarcted pigs were euthanized after 2h of reperfusion for histological assessment of infarct size and "no reflow" area. RESULTS In infarcted rats, intracoronary infusion of 4-CLD resulted in acute reduction of the "no reflow" area and conferred durable long-term structural and functional benefits (reduction in infarct size, attenuation of adverse remodeling, improvement in global systolic function). In infarcted pigs, intracoronary infusion of 4-CLD was well-tolerated from a hemodynamic standpoint and resulted in acute reduction in infarct size, reduction in "no reflow" area and more rapid resolution of ST-segment elevation. CONCLUSIONS In a rat model of myocardial infarction, intracoronary administration of 4-CLD attenuated the "no reflow" phenomenon and produced long-term structural and functional benefits. In a porcine model of myocardial infarction intracoronary administration of 4-CLD did not raise safety concerns and conferred acute cardioprotective effects.
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16
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Cacheux F, Médran-Navarrete V, Dollé F, Marguet F, Puech F, Damont A. Synthesis and in vitro characterization of novel fluorinated derivatives of the translocator protein 18 kDa ligand CfO-DPA-714. Eur J Med Chem 2016; 125:346-359. [PMID: 27688189 DOI: 10.1016/j.ejmech.2016.09.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/07/2016] [Accepted: 09/08/2016] [Indexed: 11/30/2022]
Abstract
The translocator protein 18 kDa (TSPO) is today a validated target for a number of therapeutic applications, but also a well-recognized diagnostic/imaging biomarker for the evaluation of inflammatory related-disease state and progression, prompting the development of specific and dedicated TSPO ligands worldwide. For this purpose, pyrazolo[1,5-a]pyrimidine acetamides constitute a unique class of high affinity and selectivity TSPO ligands; it includes DPA-714, a fluorine-containing derivative that has also been labelled with the positron-emitter fluorine-18, and is nowadays widely used as a Positron Emission Tomography imaging probe. Recently, to prevent defluorination issues encountered in vivo with this tracer, a first series of analogues was reported where the oxygen atom bridging the phenyl ring of the core structure and the fluorinated moiety was replaced with a more robust linkage. Among this new series, CfO-DPA-714 was discovered as a highly promising TSPO ligand. Herein, a novel series of fluorinated analogues of the latter molecule were synthesized and in vitro characterized, where the pharmacomodulation at the amide position of the molecule was explored. Thirteen compounds were thus prepared from a common key-ester intermediate (synthesized in 7 steps from 4-iodobenzoate - 11% overall yield) and a set of commercially available amines and obtained with moderate to good yields (23-81%) and high purities (>95%). With one exception, all derivatives displayed nanomolar to subnanomolar affinity for the TSPO and also high selectivity versus the CBR (Ki (CBR)/Ki (TSPO) > 103). Within this series, three compounds showed better Ki values (0.25, 0.26 and 0.30 nM) than that of DPA-714 (0.91 nM) and CfO-DPA-714 (0.37 nM), and favorable lipophilicity for brain penetration (3.6 < logD7.4 < 4.4). Among these three compounds, the N-methyl-N-propyl amide analogue (9) exhibited similar metabolic stability when compared to CfO-DPA-714 in mouse, rat and human microsomes. Therefore, the latter compound stands out as a promising candidate for drug development or for use as a PET probe, once fluorine-18-labelled, for in vivo neuroinflammation imaging.
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Affiliation(s)
- Fanny Cacheux
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France; Inserm/CEA/Université Paris Sud, UMR 1023, ERL 9218 CNRS, IMIV, Université Paris-Saclay, Orsay, France
| | - Vincent Médran-Navarrete
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France; Inserm/CEA/Université Paris Sud, UMR 1023, ERL 9218 CNRS, IMIV, Université Paris-Saclay, Orsay, France
| | - Frédéric Dollé
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France; Inserm/CEA/Université Paris Sud, UMR 1023, ERL 9218 CNRS, IMIV, Université Paris-Saclay, Orsay, France
| | | | | | - Annelaure Damont
- CEA, I2BM, Service Hospitalier Frédéric Joliot, Orsay, France; Inserm/CEA/Université Paris Sud, UMR 1023, ERL 9218 CNRS, IMIV, Université Paris-Saclay, Orsay, France.
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Shackebaei D, Feizollahi F, Hesari M, Bahrami G. The Effect of Diazepam on the Function of Hypertrophied Rats’ Hearts in Ischemia-Reperfusion Conditions. Int Cardiovasc Res J 2016. [DOI: 10.17795/icrj-10(2)89] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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18
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Morin D, Musman J, Pons S, Berdeaux A, Ghaleh B. Mitochondrial translocator protein (TSPO): From physiology to cardioprotection. Biochem Pharmacol 2015; 105:1-13. [PMID: 26688086 DOI: 10.1016/j.bcp.2015.12.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/04/2015] [Indexed: 01/08/2023]
Abstract
The mitochondrial translocator protein (TSPO) is a high affinity cholesterol binding protein which is primarily located in the outer mitochondrial membrane where it has been shown to interact with proteins implicated in mitochondrial permeability transition pore (mPTP) formation. TSPO is found in different species and is expressed at high levels in tissues that synthesize steroids but is also present in other peripheral tissues especially in the heart. TSPO has been involved in the import of cholesterol into mitochondria, a key step in steroidogenesis. This constitutes the main established function of the protein which was recently challenged by genetic studies. TSPO has also been associated directly or indirectly with a wide range of cellular functions such as apoptosis, cell proliferation, differentiation, regulation of mitochondrial function or porphyrin transport. In the heart the role of TSPO remains undefined but a growing body of evidence suggests that TSPO plays a critical role in regulating physiological cardiac function and that TSPO ligands may represent interesting drugs to protect the heart under pathological conditions. This article briefly reviews current knowledge regarding TSPO and discusses its role in the cardiovascular system under physiological and pathologic conditions. More particularly, it provides evidence that TSPO can represent an alternative strategy to develop new pharmacological agents to protect the myocardium against ischemia-reperfusion injury.
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Affiliation(s)
- Didier Morin
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
| | - Julien Musman
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
| | - Sandrine Pons
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
| | - Alain Berdeaux
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
| | - Bijan Ghaleh
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
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19
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Joo HK, Lee YR, Kang G, Choi S, Kim CS, Ryoo S, Park JB, Jeon BH. The 18-kDa Translocator Protein Inhibits Vascular Cell Adhesion Molecule-1 Expression via Inhibition of Mitochondrial Reactive Oxygen Species. Mol Cells 2015; 38:1064-70. [PMID: 26608360 PMCID: PMC4696997 DOI: 10.14348/molcells.2015.0165] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 09/25/2015] [Accepted: 09/30/2015] [Indexed: 12/31/2022] Open
Abstract
Translocator protein 18 kDa (TSPO) is a mitochondrial outer membrane protein and is abundantly expressed in a variety of organ and tissues. To date, the functional role of TSPO on vascular endothelial cell activation has yet to be fully elucidated. In the present study, the phorbol 12-myristate 13-acetate (PMA, 250 nM), an activator of protein kinase C (PKC), was used to induce vascular endothelial activation. Adenoviral TSPO overexpression (10-100 MOI) inhibited PMA-induced vascular cell adhesion molecule-1 (VCAM-1) and intracellular cell adhesion molecule-1 (ICAM-1) expression in a dose dependent manner. PMA-induced VCAM-1 expressions were inhibited by Mito-TEMPO (0.1-0.5 μM), a specific mitochondrial antioxidants, and cyclosporin A (1-5 μM), a mitochondrial permeability transition pore inhibitor, implying on an important role of mitochondrial reactive oxygen species (ROS) on the endothelial activation. Moreover, adenoviral TSPO overexpression inhibited mitochondrial ROS production and manganese superoxide dismutase expression. On contrasts, gene silencing of TSPO with siRNA increased PMA-induced VCAM-1 expression and mitochondrial ROS production. Midazolam (1-50 μM), TSPO ligands, inhibited PMA-induced VCAM-1 and mitochondrial ROS production in endothelial cells. These results suggest that mitochondrial TSPO can inhibit PMA-induced endothelial inflammation via suppression of VCAM-1 and mitochondrial ROS production in endothelial cells.
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Affiliation(s)
- Hee Kyoung Joo
- Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747,
Korea
| | - Yu Ran Lee
- Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747,
Korea
| | - Gun Kang
- Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747,
Korea
| | - Sunga Choi
- Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747,
Korea
| | - Cuk-Seong Kim
- Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747,
Korea
| | - Sungwoo Ryoo
- Department of Biological Sciences, College of Natural Sciences, Kangwon National University, Chunchon 200-701,
Korea
| | - Jin Bong Park
- Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747,
Korea
| | - Byeong Hwa Jeon
- Infectious Signaling Network Research Center and Research Institute for Medical Sciences, Department of Physiology, School of Medicine, Chungnam National University, Daejeon 301-747,
Korea
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TSPO ligand residence time influences human glioblastoma multiforme cell death/life balance. Apoptosis 2015; 20:383-98. [PMID: 25413799 DOI: 10.1007/s10495-014-1063-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ligands addressed to the mitochondrial Translocator Protein (TSPO) have been suggested as cell death/life and steroidogenesis modulators. Thus, TSPO ligands have been proposed as drug candidates in several diseases; nevertheless, a correlation between their binding affinity and in vitro efficacy has not been demonstrated yet, questioning the specificity of the observed effects. Since drug-target residence time is an emerging parameter able to influence drug pharmacological features, herein, the interaction between TSPO and irDE-MPIGA, a covalent TSPO ligand, was investigated in order to explore TSPO control on death/life processes in a standardized glioblastoma cell setting. After 90 min irDE-MPIGA cell treatment, 25 nM ligand concentration saturated irreversibly all TSPO binding sites; after 24 h, TSPO de-novo synthesis occurred and about 40 % TSPO binding sites resulted covalently bound to irDE-MPIGA. During cell culture treatments, several dynamic events were observed: (a) early apoptotic markers appeared, such as mitochondrial membrane potential collapse (at 3 h) and externalization of phosphatidylserine (at 6 h); (b) cell viability was reduced (at 6 h), without cell cycle arrest. After digitonin-permeabilized cell suspension treatment, a modulation of mitochondrial permeability transition pore was evidenced. Similar effects were elicited by the reversible TSPO ligand PIGA only when applied at micromolar dose. Interestingly, after 6 h, irDE-MPIGA cell exposure restored cell survival parameters. These results highlighted the ligand-target residence time and the cellular setting are crucial parameters that should be taken into account to understand the drug binding affinity and efficacy correlation and, above all, to translate efficiently cellular drug responses from bench to bedside.
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Habicht KL, Singh NS, Indig FE, Wainer IW, Moaddel R, Shimmo R. The development of mitochondrial membrane affinity chromatography columns for the study of mitochondrial transmembrane proteins. Anal Biochem 2015; 484:154-61. [PMID: 26049098 DOI: 10.1016/j.ab.2015.05.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/27/2015] [Accepted: 05/29/2015] [Indexed: 11/18/2022]
Abstract
Mitochondrial membrane fragments from U-87 MG (U87MG) and HEK-293 cells were successfully immobilized onto immobilized artificial membrane (IAM) chromatographic support and surface of activated open tubular (OT) silica capillary, resulting in mitochondrial membrane affinity chromatography (MMAC) columns. Translocator protein (TSPO), located in mitochondrial outer membrane as well as sulfonylurea and mitochondrial permeability transition pore (mPTP) receptors, localized to the inner membrane, were characterized. Frontal displacement experiments with multiple concentrations of dipyridamole (DIPY) and PK-11195 were run on MMAC (U87MG) column, and the binding affinities (Kd) determined were 1.08±0.49 and 0.0086±0.0006μM, respectively, consistent with previously reported values. Furthermore, binding affinities (Ki) for DIPY binding site were determined for TSPO ligands, PK-11195, mesoporphyrin IX, protoporphyrin IX, and rotenone. In addition, the relative ranking of these TSPO ligands based on single displacement studies using DIPY as marker on MMAC (U87MG) was consistent with the obtained Ki values. The immobilization of mitochondrial membrane fragments was also confirmed by confocal microscopy.
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Affiliation(s)
- K-L Habicht
- Department of Natural Sciences, Institute of Mathematics and Natural Sciences, Tallinn University, 10120 Tallinn, Estonia; Biomedical Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - N S Singh
- Biomedical Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - F E Indig
- Biomedical Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - I W Wainer
- Biomedical Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - R Moaddel
- Biomedical Research Center, National Institute on Aging, National Institutes of Health, Baltimore, MD 21224, USA
| | - R Shimmo
- Department of Natural Sciences, Institute of Mathematics and Natural Sciences, Tallinn University, 10120 Tallinn, Estonia.
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The mitochondrial translocator protein and arrhythmogenesis in ischemic heart disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:234104. [PMID: 25918579 PMCID: PMC4397036 DOI: 10.1155/2015/234104] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 03/18/2015] [Indexed: 12/19/2022]
Abstract
Mitochondrial dysfunction is a hallmark of multiple cardiovascular disorders, including ischemic heart disease. Although mitochondria are well recognized for their role in energy production and cell death, mechanisms by which they control excitation-contraction coupling, excitability, and arrhythmias are less clear. The translocator protein (TSPO) is an outer mitochondrial membrane protein that is expressed in multiple organ systems. The abundant expression of TSPO in macrophages has been leveraged to image the immune response of the heart to inflammatory processes. More recently, the recognition of TSPO as a regulator of energy-dissipating mitochondrial pathways has extended its utility from a diagnostic marker of inflammation to a therapeutic target influencing diverse pathophysiological processes. Here, we provide an overview of the emerging role of TSPO in ischemic heart disease. We highlight the importance of TSPO in the regenerative process of reactive oxygen species (ROS) induced ROS release through its effects on the inner membrane anion channel (IMAC) and the permeability transition pore (PTP). We discuss evidence implicating TSPO in arrhythmogenesis in the settings of acute ischemia-reperfusion injury and myocardial infarction.
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23
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Cheung YY, Nickels ML, Tang D, Buck JR, Manning HC. Facile synthesis of SSR180575 and discovery of 7-chloro-N,N,5-trimethyl-4-oxo-3(6-[(18)F]fluoropyridin-2-yl)-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide, a potent pyridazinoindole ligand for PET imaging of TSPO in cancer. Bioorg Med Chem Lett 2014; 24:4466-4471. [PMID: 25172419 PMCID: PMC4163096 DOI: 10.1016/j.bmcl.2014.07.091] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/29/2014] [Accepted: 07/31/2014] [Indexed: 10/24/2022]
Abstract
A novel synthesis of the translocator protein (TSPO) ligand 7-chloro-N,N,5-trimethyl-4-oxo-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide (SSR180575, 3) was achieved in four steps from commercially available starting materials. Focused structure-activity relationship development about the pyridazinoindole ring at the N3 position led to the discovery of 7-chloro-N,N,5-trimethyl-4-oxo-3(6-fluoropyridin-2-yl)-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide (14), a novel ligand of comparable affinity. Radiolabeling with fluorine-18 ((18)F) yielded 7-chloro-N,N,5-trimethyl-4-oxo-3(6-[(18)F]fluoropyridin-2-yl)-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide ([(18)F]-14) in high radiochemical yield and specific activity. In vivo studies of [(18)F]-14 revealed this agent as a promising probe for molecular imaging of glioma.
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Affiliation(s)
- Yiu-Yin Cheung
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States
| | - Michael L Nickels
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, United States
| | - Dewei Tang
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, United States
| | - Jason R Buck
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, United States
| | - H Charles Manning
- Vanderbilt University Institute of Imaging Science (VUIIS), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Program in Chemical and Physical Biology, Vanderbilt University Medical Center, Nashville, TN 37232, United States; Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University Medical Center, Nashville, TN 37232, United States; Department of Biomedical Engineering, Vanderbilt University, Nashville, TN 37232, United States; Department of Neurosurgery, Vanderbilt University Medical Center, Nashville, TN 37232, United States
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de Tassigny AD, Assaly R, Schaller S, Pruss RM, Berdeaux A, Morin D. Mitochondrial translocator protein (TSPO) ligands prevent doxorubicin-induced mechanical dysfunction and cell death in isolated cardiomyocytes. Mitochondrion 2013; 13:688-97. [PMID: 24121045 DOI: 10.1016/j.mito.2013.10.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 10/01/2013] [Accepted: 10/03/2013] [Indexed: 11/29/2022]
Abstract
Contractile dysfunction and subsequent development of cardiomyopathies are well known limiting factors in the treatment of cancer with doxorubicin and have been linked to mitochondrial dysfunction. Here, using adult isolated paced cardiomyocytes, we have demonstrated that ligands of translocator protein (TSPO) 4'-chlorodiazepam and TRO40303 prevented the doxorubicin-induced alterations in contractility and improved cardiomyocyte viability. This cardioprotective effect was closely associated with both a potent reduction in reactive oxygen species production and inhibition of mitochondrial permeability transition pore opening. Thus, preventive administration of TSPO ligands may represent a novel pharmacological strategy to protect the heart during doxorubicin treatment.
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Affiliation(s)
- Alexandra d'Anglemont de Tassigny
- INSERM U955, équipe 3, Créteil F-94010, France; Université Paris-Est, Faculté de Médecine, Créteil F-94010, France; Institut Supérieur des BioSciences, Faculté de Médecine, Créteil F-94010, France
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Connors NJ, Hoffman RS. Experimental Treatments for Cocaine Toxicity: A Difficult Transition to the Bedside. J Pharmacol Exp Ther 2013; 347:251-7. [DOI: 10.1124/jpet.113.206383] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Paradis S, Leoni V, Caccia C, Berdeaux A, Morin D. Cardioprotection by the TSPO ligand 4'-chlorodiazepam is associated with inhibition of mitochondrial accumulation of cholesterol at reperfusion. Cardiovasc Res 2013; 98:420-7. [PMID: 23554458 DOI: 10.1093/cvr/cvt079] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
AIMS The translocator protein (TSPO) is located on the outer mitochondrial membrane where it is responsible for the uptake of cholesterol into mitochondria of steroidogenic organs. TSPO is also present in the heart where its role remains uncertain. We recently showed that TSPO ligands reduced infarct size and improved mitochondrial functions after ischaemia-reperfusion. This study, thus, sought to determine whether cholesterol could play a role in the cardioprotective effect of TSPO ligands. METHODS AND RESULTS In a model of 30 min coronary occlusion/15 min reperfusion in Wistar rat, we showed that reperfusion induced lipid peroxidation as demonstrated by the increase in conjugated diene and thiobarbituric acid reactive substance formation and altered mitochondrial function (decrease in oxidative phosphorylation and increase in the sensitivity of mitochondrial permeability transition pore opening) in ex-vivo isolated mitochondria. This was associated with an increase in mitochondrial cholesterol uptake (89.5 ± 12.2 vs. 39.9 ± 3.51 nmol/mg protein in controls, P < 0.01) and a subsequent strong generation of auto-oxidized oxysterols, i.e. 7α- and 7β-hydroxycholesterol, 7-ketocholesterol, cholesterol-5α,6α-epoxide, and 5β,6β-epoxide (+173, +149, +165, +165, and +193% vs. controls, respectively; P < 0.01). Administration of the selective TSPO ligand 4'-chlorodiazepam inhibited oxidative stress, improved mitochondrial function, and abolished both mitochondrial cholesterol accumulation and oxysterol production. This was also observed with the new TSPO ligand TRO40303. CONCLUSION These data suggest that 4'-chlorodiazepam inhibits oxidative stress and oxysterol formation by reducing the accumulation of cholesterol in the mitochondrial matrix at reperfusion and prevents mitochondrial injury. This new and original mechanism may contribute to the cardioprotective properties of TSPO ligands.
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Affiliation(s)
- Stéphanie Paradis
- INSERM, U955, Equipe 3, 8 rue du Général Sarrail, Créteil Cedex 94000, France
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Inhibition of p38 MAPK During Ischemia, But Not Reperfusion, Effectively Attenuates Fatal Arrhythmia in Ischemia/Reperfusion Heart. J Cardiovasc Pharmacol 2013; 61:133-41. [DOI: 10.1097/fjc.0b013e318279b7b1] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Walters AM, Porter GA, Brookes PS. Mitochondria as a drug target in ischemic heart disease and cardiomyopathy. Circ Res 2013; 111:1222-36. [PMID: 23065345 DOI: 10.1161/circresaha.112.265660] [Citation(s) in RCA: 204] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ischemic heart disease is a significant cause of morbidity and mortality in Western society. Although interventions, such as thrombolysis and percutaneous coronary intervention, have proven efficacious in ischemia and reperfusion injury, the underlying pathological process of ischemic heart disease, laboratory studies suggest further protection is possible, and an expansive research effort is aimed at bringing new therapeutic options to the clinic. Mitochondrial dysfunction plays a key role in the pathogenesis of ischemia and reperfusion injury and cardiomyopathy. However, despite promising mitochondria-targeted drugs emerging from the laboratory, very few have successfully completed clinical trials. As such, the mitochondrion is a potential untapped target for new ischemic heart disease and cardiomyopathy therapies. Notably, there are a number of overlapping therapies for both these diseases, and as such novel therapeutic options for one condition may find use in the other. This review summarizes efforts to date in targeting mitochondria for ischemic heart disease and cardiomyopathy therapy and outlines emerging drug targets in this field.
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Affiliation(s)
- Andrew M Walters
- School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, NY 14642, USA
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Translocator protein (18 kDa): a promising therapeutic target and diagnostic tool for cardiovascular diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2012; 2012:162934. [PMID: 23251719 PMCID: PMC3516045 DOI: 10.1155/2012/162934] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 10/22/2012] [Accepted: 11/04/2012] [Indexed: 01/15/2023]
Abstract
The translocator protein (18 kDa) (TSPO) is a five transmembrane domain protein in mitochondria, abundantly expressed in a variety of organs and tissues. TSPO contributes to a wide range of biological processes, including cholesterol transportation, mitochondrial membrane potential and respiratory chain regulation, apoptosis, and oxidative stress. Recent studies have demonstrated that TSPO might also be involved in the physiological regulation of cardiac chronotropy and inotropy. Accordingly, TSPO ligands play significant roles in protecting the cardiovascular systems under pathological conditions through cardiac electrical activity retention, intracellular calcium maintenance, mitochondrial energy provision, mitochondrial membrane potential equilibrium, and reactive oxygen species inhibition. This paper focuses on the physiological and pathological characteristics of TSPO in the cardiovascular systems and also summarizes the properties of TSPO ligands. TSPO represents a potential therapeutic target and diagnostic tool for cardiovascular diseases including arrhythmia, myocardial infarction, cardiac hypertrophy, atherosclerosis, myocarditis, and large vessel vasculitis.
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Méndez-Cuesta LA, Márquez-Valadez B, Pérez-De La Cruz V, Escobar-Briones C, Galván-Arzate S, Alvarez-Ruiz Y, Maldonado PD, Santana RA, Santamaría A, Carrillo-Mora P. Diazepam blocks striatal lipid peroxidation and improves stereotyped activity in a rat model of acute stress. Basic Clin Pharmacol Toxicol 2011; 109:350-6. [PMID: 21645264 DOI: 10.1111/j.1742-7843.2011.00738.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In this work, the effect of a single dose of diazepam was tested on different markers of oxidative damage in the striatum of rats in an acute model of immobilization (restraint) stress. In addition, the locomotor activity was measured at the end of the restraint period. Immobilization was induced to animals for 24 hr, and then, lipid peroxidation, superoxide dismutase activity and content, and mitochondrial function were all estimated in striatal tissue samples. Corticosterone levels were measured in serum. Diazepam was given to rats as a pre-treatment (1 mg/kg, i.p.) 20 min. before the initiation of stress. Our results indicate that acute stress produced enhanced striatal levels of lipid peroxidation (73% above the control), decreased superoxide dismutase activity (54% below the control), reduced levels of mitochondrial function (35% below the control) and increased corticosterone serum levels (86% above the control). Pre-treatment of stressed rats with diazepam decreased the striatal lipid peroxidation levels (68% below the stress group) and improved mitochondrial function (18% above the stress group), but only mild preservation of superoxide dismutase activity was detected (17% above the stress group). In regard to the motor assessment, only the stereotyped activity was increased in the stress group with respect to control (46% above the control), and this effect was prevented by diazepam administration (30% below the stress group). The preventive actions of diazepam in this acute model of stress suggest that drugs exhibiting anxiolytic and antioxidant properties might be useful for the design of therapies against early acute phases of physic stress.
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Affiliation(s)
- Luis A Méndez-Cuesta
- Laboratorio de Aminoácidos Excitadores, Instituto Nacional de Neurología y Neurocirugía, México City, Mexico
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Li J, Xu J, Xiao J, Zhang H, Liang D, Liu Y, Zhang Y, Liu Y, Wen W, Hu Y, Yu Z, Yan B, Jiang B, Zhou ZN, Chen YH. Preservation of TSPO by chronic intermittent hypobaric hypoxia confers antiarrhythmic activity. J Cell Mol Med 2011; 15:134-40. [PMID: 19863695 PMCID: PMC3822500 DOI: 10.1111/j.1582-4934.2009.00949.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Abnormal activation of mitochondrial translocator protein (TSPO) contributes to arrhythmogenesis during cardiac metabolic compromise; however, its role in the antiarrhythmic activities of chronic hypoxia adaptation remains unclear. Our results demonstrated that 80% of normoxic rats developed ischaemic VF, whereas this condition was seldom observed in rats with 14 days of chronic intermittent hypobaric hypoxia (CIHH). TSPO stimulation or inhibition affected the arrhythmias incidence in normoxic rats, but did not change the CIHH-mediated antiarrhythmic effects. Abrupt and excessive elevation of TSPO activity was positively linked to ischaemic VF, and CIHH preserved TSPO activity during ischaemia. The preservation of TSPO activity by CIHH also contributed to the maintenance of intracellular Ca homeostasis. These results suggest that the blunt sensitivity of TSPO to ischaemic stress may be responsible for the antiarrhythmic effects by CIHH.
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Affiliation(s)
- Jun Li
- Key Laboratory of Arrhythmias, Ministry of Education of China, Shanghai, China
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Surinkaew S, Chattipakorn S, Chattipakorn N. Roles of mitochondrial benzodiazepine receptor in the heart. Can J Cardiol 2011; 27:262.e3 -13. [PMID: 21459278 DOI: 10.1016/j.cjca.2010.12.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 06/02/2010] [Indexed: 12/01/2022] Open
Abstract
Mitochondrial benzodiazepine receptor (mBzR) is a type of peripheral benzodiazepine receptor that is located in the outer membrane of mitochondria. It is an 18-kDa protein that can form a multimeric complex with voltage-dependent anion channel (32 kDa) and adenine nucleotide translocator (30 kDa). mBzR is found in various species and abundantly distributed in peripheral tissues, including the cardiovascular system. The mitochondria are well known as the site of energy production, and the heart is the organ that highly requires this energy supply. In the past decades, it has been shown that mBzR plays a critical role in regulating mitochondrial and heart functions. A growing body of evidence demonstrates that mBzR is associated with regulation of mitochondrial respiration, mitochondrial membrane potential, apoptosis, and reactive oxygen species production. Moreover, mBzR has been suggested to play a role in alteration of physiological effects in the heart such as contractility and heart rate. mBzR is involved in the pathologic condition such as ischemia/reperfusion injury, responses to stress, and changes in electrophysiological properties and arrhythmogenesis. In this review, evidence of the roles of mBzR in the heart under both physiological and pathologic conditions is presented. Clinical studies regarding the use of pharmacologic intervention involving mBzR in the heart are also discussed as a possible target for the treatment of electrical and mechanical dysfunction in the heart.
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Affiliation(s)
- Sirirat Surinkaew
- Department of Physiology, Chiang Mai University, Chiang Mai, Thailand
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Thominiaux C, Damont A, Kuhnast B, Demphel S, Le Helleix S, Boisnard S, Rivron L, Chauveau F, Boutin H, Van Camp N, Boisgard R, Roy S, Allen J, Rooney T, Benavides J, Hantraye P, Tavitian B, Dollé F. Radiosynthesis of 7-chloro-N,N-dimethyl-5-[11C]methyl-4-oxo-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide, [11C]SSR180575, a novel radioligand for imaging the TSPO (peripheral benzodiazepine receptor) with PET. J Labelled Comp Radiopharm 2010. [DOI: 10.1002/jlcr.1794] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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In vivo imaging of neuroinflammation in the rodent brain with [11C]SSR180575, a novel indoleacetamide radioligand of the translocator protein (18 kDa). Eur J Nucl Med Mol Imaging 2010; 38:509-14. [PMID: 20936410 DOI: 10.1007/s00259-010-1628-5] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Accepted: 09/09/2010] [Indexed: 10/19/2022]
Abstract
PURPOSE Neuroinflammation is involved in neurological disorders through the activation of microglial cells. Imaging of neuroinflammation with radioligands for the translocator protein (18 kDa) (TSPO) could prove to be an attractive biomarker for disease diagnosis and therapeutic evaluation. The indoleacetamide-derived 7-chloro-N,N,5-trimethyl-4-oxo-3-phenyl-3,5-dihydro-4H-pyridazino[4,5-b]indole-1-acetamide, SSR180575, is a selective high-affinity TSPO ligand in human and rodents with neuroprotective effects. METHODS Here we report the radiolabelling of SSR180575 with (11)C and in vitro and in vivo imaging in an acute model of neuroinflammation in rats. RESULTS The image contrast and the binding of [(11)C]SSR180575 are higher than that obtained with the isoquinoline-based TSPO radioligand, [(11)C]PK11195. Competition studies demonstrate that [(11)C]SSR180575 has high specific binding for the TSPO. CONCLUSION [(11)C]SSR180575 is the first PET radioligand for the TSPO based on an indoleacetamide scaffold designed for imaging neuroinflammation in animal models and in the clinic.
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In vivo imaging and quantitative analysis of TSPO in rat peripheral tissues using small-animal PET with [18F]FEDAC. Nucl Med Biol 2010; 37:853-60. [DOI: 10.1016/j.nucmedbio.2010.04.183] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 04/19/2010] [Accepted: 04/19/2010] [Indexed: 11/23/2022]
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Leducq-Alet N, Vin V, Savi P, Bono F. TNF-alpha induced PMN apoptosis in whole human blood: Protective effect of SSR180575, a potent and selective peripheral benzodiazepine ligand. Biochem Biophys Res Commun 2010; 399:475-9. [DOI: 10.1016/j.bbrc.2010.07.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2010] [Accepted: 07/03/2010] [Indexed: 10/19/2022]
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Jaiswal A, Kumar S, Enjamoori R, Seth S, Dinda AK, Maulik SK. Peripheral benzodiazepine receptor ligand Ro5-4864 inhibits isoprenaline-induced cardiac hypertrophy in rats. Eur J Pharmacol 2010; 644:146-53. [PMID: 20621082 DOI: 10.1016/j.ejphar.2010.06.058] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Revised: 06/03/2010] [Accepted: 06/24/2010] [Indexed: 01/04/2023]
Abstract
Oxidative stress plays a significant role in the pathogenesis of cardiac hypertrophy. Peripheral benzodiazepine receptors are ubiquitously expressed in various tissues, including the heart. Peripheral benzodiazepine receptors have been reported to be involved in the protection of cells against oxygen radical damage. The present study was designed to determine whether Ro5-4864 (a peripheral benzodiazepine receptor ligand) can inhibit isoprenaline-induced cardiac hypertrophy. Male Wistar rats (body weight 150-200g) were administered, isoprenaline (5mg/kg, body weight, subcutaneously) alone or along with Ro5-4864 (0.1 and 0.5mg/kg, body weight, intraperitoneally) once daily for 14days. Control rats received normal saline subcutaneously (1.0ml/kg). Isoprenaline-induced changes in heart weight to body weight ratio, left ventricular wall thickness (M-mode echocardiography and gross morphometry) and myocyte size were significantly prevented by both the doses of Ro5-4864. Ro5-4864 also attenuated isoprenaline-induced increase in interstitial fibrosis, lipid peroxidation and changes in endogenous antioxidants (glutathione, superoxide dismutase and catalase). Isoprenaline-induced cardiac hypertrophy was associated with increased expression of beta myosin heavy chain, which was also prevented by Ro5-4864. This is the first study to demonstrate a salutary effect of Ro5-4864 in experimental cardiac hypertrophy.
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Affiliation(s)
- Amardeep Jaiswal
- Department of Pharmacology, All India Institute of Medical Sciences, New Delhi-110029, India.
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Momosaki S, Imamoto N, Hosoi R, Sawada Y, Abe K, Zhang MR, Inoue O. PK11195 might selectively suppress the quinolinic acid-induced enhancement of anaerobic glycolysis in glial cells. Brain Res 2010; 1340:18-23. [PMID: 20435022 DOI: 10.1016/j.brainres.2010.04.063] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 04/22/2010] [Accepted: 04/23/2010] [Indexed: 01/01/2023]
Abstract
PK11195 was previously reported to attenuate the quinolinic acid (QUIN)-induced enhancement of glucose metabolism in rat brain. In the present study, the effect of PK11195 or anesthesia on [(14)C]2-deoxyglucose ([(14)C]DG) uptake was investigated in order to determine whether the QUIN-induced enhancement of glucose metabolism occurred in glial cells or neurons. We confirmed that the microinjection of QUIN caused a significant enhancement of [(14)C]DG uptake at 2h after the infusion, while the co-injection of PK11195 and QUIN almost completely suppressed this enhancement of [(14)C]DG uptake. No effect of chloral hydrate anesthesia on the QUIN-induced enhancement of [(14)C]DG uptake was observed. In contrast to rats treated with QUIN, PK11195 did not affect the enhancement of [(14)C]DG uptake induced by fluorocitrate (FC); however, chloral hydrate anesthesia completely suppressed the FC-induced increase in [(14)C]DG uptake. These results indicated that the enhancement of glucose metabolism induced by QUIN mainly occurred in glial cells, and the neuroprotective effect of PK11195 in rats injected with QUIN might be related to the suppression of anaerobic glycolysis in glial cells.
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Affiliation(s)
- Sotaro Momosaki
- Division of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamada-oka, Suita, Osaka 565-0871, Japan.
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Xiao J, Liang D, Zhang H, Liu Y, Li F, Chen YH. 4'-Chlorodiazepam, a translocator protein (18 kDa) antagonist, improves cardiac functional recovery during postischemia reperfusion in rats. Exp Biol Med (Maywood) 2010; 235:478-86. [PMID: 20407080 DOI: 10.1258/ebm.2009.009291] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inhibition of translocator protein (18 kDa) (TSPO) can effectively prevent reperfusion-induced arrhythmias and improve postischemic contractile performance. Mitochondrial permeability transition pore (mPTP) opening, mediated mainly through oxidative stress during ischemia/reperfusion (I/R), is a key event in reperfusion injury. 4'-Chlorodiazepam is a widely used TSPO antagonist. However, whether 4'-chlorodiazepam can improve cardiac functional recovery during postischemia reperfusion by affecting oxidative enzymes, reducing reactive oxygen species (ROS) and thereby inhibiting mPTP opening is still unknown. Cardiac function including heart rate, coronary flow rate, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP), maximal time derivatives of pressure (+/-dP/dt max) and the severity of ventricular arrhythmias were analyzed in isolated rat hearts during I/R. mPTP opening, ROS and oxidative enzyme activities were measured with fluorometric or spectrophotometric techniques. 4'-Chlorodiazepam did not affect heart rate and coronary flow rate, but abolished the increase in LVEDP, accelerated the recovery of LVDP and +/-dP/dt max, and reduced the severity of ventricular arrhythmias. The mPTP opening probability was reduced by 4'-chlorodiazepam, accompanied by a reduction in ROS level. In addition, the activities of mitochondrial electron transport chain complex I and complex III were increased, while those of xanthine oxidase and NADPH oxidase were reduced. Therefore, 4'-chlorodiazepam may improve cardiac functional recovery during reperfusion, potentially by affecting the activities of oxidative enzymes, reducing ROS and thereby inhibiting mPTP opening. The present study presents evidence that 4'-chlorodiazepam could be a novel adjunct to reperfusion.
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Affiliation(s)
- Junjie Xiao
- Department of Cardiology, Tongji Hospital, Tongji University School of Medicine, Shanghai 200092, China
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Schaller S, Paradis S, Ngoh GA, Assaly R, Buisson B, Drouot C, Ostuni MA, Lacapere JJ, Bassissi F, Bordet T, Berdeaux A, Jones SP, Morin D, Pruss RM. TRO40303, a New Cardioprotective Compound, Inhibits Mitochondrial Permeability Transition. J Pharmacol Exp Ther 2010; 333:696-706. [DOI: 10.1124/jpet.110.167486] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Mazurika C, Veenman L, Weizman R, Bidder M, Leschiner S, Golani I, Spanier I, Weisinger G, Gavish M. Estradiol modulates uterine 18 kDa translocator protein gene expression in uterus and kidney of rats. Mol Cell Endocrinol 2009; 307:43-9. [PMID: 19524125 DOI: 10.1016/j.mce.2009.04.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2008] [Revised: 03/30/2009] [Accepted: 04/02/2009] [Indexed: 11/19/2022]
Abstract
We examined the effect of ovariectomy, with and without estradiol treatment, on 18 kDa translocator protein (TSPO) gene expression and its binding density in the uterus and kidney of rats. Ovariectomy causes a significant decrease in uterine, but not renal TSPO binding density, while estradiol treatment of ovariectomized rats restored TSPO binding density in the uterus. These TSPO density levels did not correlate with steady state or new RNA transcription. Our in vivo study suggests that estradiol is responsible for the maintenance of uterine TSPO density via transcriptional mechanisms. Our in vivo study also suggests that in the kidney estradiol appears to operate via post-transcriptional mechanisms to maintain TSPO density.
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Affiliation(s)
- Caroline Mazurika
- Department of Molecular Pharmacology, the Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
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Zorov DB, Juhaszova M, Yaniv Y, Nuss HB, Wang S, Sollott SJ. Regulation and pharmacology of the mitochondrial permeability transition pore. Cardiovasc Res 2009; 83:213-25. [PMID: 19447775 PMCID: PMC2701724 DOI: 10.1093/cvr/cvp151] [Citation(s) in RCA: 185] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 05/04/2009] [Accepted: 05/10/2009] [Indexed: 12/18/2022] Open
Abstract
The 'mitochondrial permeability transition', characterized by a sudden induced change of the inner mitochondrial membrane permeability for water as well as for small substances (=1.5 kDa), has been known for three decades. Research interest in the entity responsible for this phenomenon, the 'mitochondrial permeability transition pore' (mPTP), has dramatically increased after demonstration that it plays a key role in the life and death decision in cells. Therefore, a better understanding of this phenomenon and its regulation by environmental stresses, kinase signalling, and pharmacological intervention is vital. The characterization of the molecular identity of the mPTP will allow identification of possible pharmacological targets and assist in drug design for its precise regulation. However, despite extensive research efforts, at this point the pore-forming core component(s) of the mPTP remain unidentified. Pivotal new genetic evidence has shown that components once believed to be core elements of the mPTP (namely mitochondrial adenine nucleotide translocator and cyclophilin D) are instead only mPTP regulators (or in the case of voltage-dependent anion channels, probably entirely dispensable). This review provides an update on the current state of knowledge regarding the regulation of the mPTP.
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Affiliation(s)
| | | | | | | | | | - Steven J. Sollott
- Laboratory of Cardiovascular Science, Gerontology Research Center, Box 13, Intramural Research Program, National Institute on Aging, NIH, 5600 Nathan Shock Drive, Baltimore, MD 21224-6825, USA
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Rosenthal RA, Huffman KD, Fisette LW, Damphousse CA, Callaway WB, Malfroy B, Doctrow SR. Orally available Mn porphyrins with superoxide dismutase and catalase activities. J Biol Inorg Chem 2009; 14:979-91. [PMID: 19504132 PMCID: PMC2716445 DOI: 10.1007/s00775-009-0550-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Accepted: 05/18/2009] [Indexed: 12/04/2022]
Abstract
Superoxide dismutase/catalase mimetics, such as salen Mn complexes and certain metalloporphyrins, catalytically neutralize reactive oxygen and nitrogen species, which have been implicated in the pathogenesis of many serious diseases. Both classes of mimetic are protective in animal models of oxidative stress. However, only AEOL11207 and EUK-418, two uncharged Mn porphyrins, have been shown to be orally bioavailable. In this study, EUK-418 and several new analogs (the EUK-400 series) were synthesized and shown to exhibit superoxide dismutase, catalase, and peroxidase activities in vitro. Some also protected PC12 cells against staurosporine-induced cell death. All EUK-400 compounds were stable in simulated gastric fluid, and most were substantially more lipophilic than the salen Mn complexes EUK-189 and EUK-207, which lack oral activity. Pharmacokinetics studies demonstrate the presence of all EUK-400 series compounds in the plasma of rats after oral administration. These EUK-400 series compounds are potential oral therapeutic agents for cellular damage caused by oxidative stress.
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Favreau F, Rossard L, Zhang K, Desurmont T, Manguy E, Belliard A, Fabre S, Liu J, Han Z, Thuillier R, Papadopoulos V, Hauet T. Expression and modulation of translocator protein and its partners by hypoxia reoxygenation or ischemia and reperfusion in porcine renal models. Am J Physiol Renal Physiol 2009; 297:F177-90. [PMID: 19386723 DOI: 10.1152/ajprenal.90422.2008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Translocator protein (TSPO), formerly known as the peripheral-type benzodiazepine receptor, is an 18-kDa drug- and cholesterol-binding protein localized to the outer mitochondrial membrane and implicated in a variety of cell and mitochondrial functions. To determine the role of TSPO in ischemia-reperfusion injury (IRI), we used both in vivo and in vitro porcine models: an in vivo renal ischemia model where different conservation modalities were tested and an in vitro model where TSPO-transfected porcine proximal tubule LLC-PK(1) cells were exposed to hypoxia and oxidative stress. The expression of TSPO and its partners in steroidogenic cells, steroidogenic acute regulatory protein (StAR) and cytochrome P-450 side chain cleavage CYP11A1, as well as the impact of TSPO overexpression and exposure to TSPO ligands in vitro in hypoxia-ischemia conditions were investigated. Hypoxia induced caspase activation, reduction of ATP content, and LLC-PK(1) cell death. Transfection and overexpression of TSPO rescued the cells from the detrimental effects of hypoxia and reoxygenation. Moreover, TSPO overexpression was accompanied by a reduction of H(2)O(2)-induced necrosis. TSPO drug ligands did not affect TSPO-mediated functions. In vivo, TSPO expression was modulated by IRI and during regeneration particularly in proximal tubule cells, which do not express this protein at the basal level. Under the same conditions, StAR and CYP11A1 protein and gene expression was reduced without apparent relation to TSPO changes. Pregnenolone was identified and measured in the pig kidney. Pregnenolone synthesis was not affected by the experimental conditions used. Taken together, these results indicate that changes in TSPO expression in kidney regenerating tissue could be important for renal protection and maintenance of kidney function.
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Affiliation(s)
- Frederic Favreau
- Inserm, U927, Faculté de Médecine, Université de Poitiers, 86021 Poitiers Cedex, France
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Bartosikova L, Necas J, Bartosik T, Frana P, Pavlik M. Changes in biomechanical parameters during heart perfusion and after midazolam pre-medication--experimental pilot study. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2008; 152:79-82. [PMID: 18795079 DOI: 10.5507/bp.2008.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Midazolam is a frequently used benzodiazepine in anaesthesiology and intensive care. AIM The aim of pilot study was to monitor its effect during heart perfusion in the laboratory rat. METHODS The same groups of animals (n = 10). The 1(st) group was treated with midazolam in a dose of 0.5mg/kg i.p. The 2(nd) group was a placebo. After i.p. administration of heparine injection of 500 IU dose, the hearts were excised and perfused (modified Langendorf's method). Working schedule: stabilization/ischaemia/reperfusion proceed at intervals of 20/30/60 min. Monitored parameters in isolated heart: left ventricle pressure (LVP), end-diastolic pressure (LVEDP), contractility (+dP/dt(max)). RESULTS The treated hearts showed improved postischemic recovery, reaching LVP values of 92 +/- 6 % at the end of the reperfusion, placebo only 61 +/- 7 %. In placebo hearts LVEDP rose from 10.0 +/- 0.5 mmHg to 43 +/- 4 mmHg after, in treated animals only about 25 mmHg. The treated hearts improved +dP/dt(max) recovery during reperfusion to 91 +/- 8 %. These values were significantly greater than those obtained from the placebo hearts. CONCLUSIONS Positive changes in monitored parameters were found in this experimental pilot study. We conclude that the administration of midazolam in laboratory rats has a cardioprotective potential against ischemia-reperfusion induced injury.
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Affiliation(s)
- Lenka Bartosikova
- Department of Physiology, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic.
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Brown DA, Aon MA, Akar FG, Liu T, Sorarrain N, O'Rourke B. Effects of 4'-chlorodiazepam on cellular excitation-contraction coupling and ischaemia-reperfusion injury in rabbit heart. Cardiovasc Res 2008; 79:141-9. [PMID: 18304929 DOI: 10.1093/cvr/cvn053] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
AIMS Recent evidence indicates that the activity of energy-dissipating ion channels in the mitochondria can influence the susceptibility of the heart to ischaemia-reperfusion injury. In this study, we describe the effects of 4'-chlorodiazepam (4-ClDzp), a well-known ligand of the mitochondrial benzodiazepine receptor, on the physiology of both isolated cardiomyocytes and intact hearts. METHODS AND RESULTS We used current- and voltage-clamp methods to determine the effects of 4-ClDzp on excitation-contraction coupling in isolated rabbit heart cells. At the level of the whole heart, we subjected rabbit hearts to ischaemia/reperfusion in order to determine how 4-ClDzp influenced the susceptibility to arrhythmias and contractile dysfunction. In isolated rabbit cardiomyocytes, 4-ClDzp evoked a significant reduction in the cardiac action potential that was associated with a decrease in calcium currents and peak intracellular calcium transients. In intact perfused normoxic rabbit hearts, 4-ClDzp mediated a dose-dependent negative inotropic response, consistent with the observation that 4-ClDzp was reducing calcium influx. Hearts that underwent 30 min of global ischaemia and 30 min of reperfusion were protected against reperfusion arrhythmias and post-ischaemic contractile impairment when 4-ClDzp (24 microM) was administered throughout the protocol or as a single bolus dose given at the onset of reperfusion. In contrast, hearts treated with cyclosporin-A, a classical blocker of the mitochondrial permeability transition pore, were not protected against reperfusion arrhythmias. CONCLUSION The findings indicate that the effects of 4-ClDzp on both mitochondrial and sarcolemmal ion channels contribute to protection against post-ischaemic cardiac dysfunction. Of clinical relevance, the compound is effective when given upon reperfusion, unlike other pre-conditioning agents.
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Affiliation(s)
- David A Brown
- Department of Medicine, Division of Cardiology, Institute of Molecular Cardiobiology, The Johns Hopkins University School of Medicine, 720 Rutland Avenue, 1059 Ross Building, Baltimore, MD 21205, USA
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Obame FN, Zini R, Souktani R, Berdeaux A, Morin D. Peripheral benzodiazepine receptor-induced myocardial protection is mediated by inhibition of mitochondrial membrane permeabilization. J Pharmacol Exp Ther 2007; 323:336-45. [PMID: 17640950 DOI: 10.1124/jpet.107.124255] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Opening of the permeability transition pore (PTP) is a key event in ischemia-reperfusion injury and several ligands of the peripheral benzodiazepine receptor (PBR), a mitochondrial outer membrane protein possibly associated with PTP, have been demonstrated as potent cardioprotective agents. Here, we investigated the mechanisms by which the specific PBR ligand 4'-chlorodiazepam (CDZ) protected the myocardium against ischemia-reperfusion. In either global or regional models of myocardial ischemia-reperfusion in rats, CDZ reduced infarct size in a dose-dependent manner (e.g., 11 +/- 1% of the area at risk at 10 mg/kg versus 31 +/- 3% in control; p < 0.05) and to a similar extent as ischemic or diazoxide-induced preconditioning. CDZ (10 mg/kg) reduced apoptosis (terminal deoxynucleotidyl transferase dUTP nick-end labeling staining), restored mitochondrial recovery, improved oxidative phosphorylation parameters, and reduced mitochondrial membrane permeabilization with inhibition of cytochrome c and apoptosis-inducing factor releases. CDZ increased the resistance of mitochondria to Ca2+-induced PTP opening. All these cardioprotective effects of CDZ were associated with an improved stabilization of the association of Bcl-2 with the mitochondrial membrane and inhibition of the association of a cytosolic fragment of Bax, occurring during ischemia-reperfusion, with the outer mitochondrial membrane. In addition, the PTP opener atractyloside (20 microM) and the Bcl-2 inhibitor ethyl-2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate (HA14-1) (20 microM) abrogated CDZ-induced reduction of infarct size. These results demonstrate that PBR occupancy by CDZ renders the heart more resistant to ischemia-reperfusion injury by limiting mitochondrial membrane permeabilization. This is due to a reorganization of the balance between pro- and antiapoptotic proteins of the Bcl-2 family proteins at the level of mitochondrial membranes.
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Affiliation(s)
- Fatou Nsoure Obame
- INSERM U841, équipe 3, Facultéde Médecine de Paris XII, 8 rue du Général Sarrail, F-94010, Créteil, France
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Li J, Wang J, Zeng Y. Peripheral benzodiazepine receptor ligand, PK11195 induces mitochondria cytochrome c release and dissipation of mitochondria potential via induction of mitochondria permeability transition. Eur J Pharmacol 2007; 560:117-22. [PMID: 17291492 DOI: 10.1016/j.ejphar.2006.12.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2006] [Revised: 12/12/2006] [Accepted: 12/18/2006] [Indexed: 10/23/2022]
Abstract
Mitochondrial permeability transition pore plays an important role in the processes of cell apoptosis and necrosis. The peripheral benzodiazepine receptor, a mitochondria outer-membrane protein, is involved in the regulation of mitochondrial permeability transition. In the present study, we test if PK11195, a peripheral benzodiazepine receptor ligand, can lead to the opening of mitochondrial permeability transition pores, and subsequently causes mitochondria cytochrome c loss and mitochondria uncoupling. In isolated cardiac mitochondria, PK11195 (50, 100, 200 microM) caused a dose-dependent mitochondrial swelling, cytochrome c loss, and the dissipation of mitochondrial potential. Cyclosporin A (0.2 microM), a specific inhibitor of mitochondrial permeability transition, completely prevented the mitochondrial swelling induced by PK11195, and maintained the cytochrome c content and membrane potential. These data suggest that peripheral benzodiazepine receptor ligand, PK11195 caused mitochondrial uncoupling and cytochrome c loss via induction of mitochondrial permeability transition.
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Affiliation(s)
- Jingyuan Li
- Department of Anesthesiology, the First Affiliated Hospital, China Medical University, Shenyang 110001, China.
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Ruffoli R, Carpi A, Giambelluca MA, Grasso L, Scavuzzo MC, Giannessi F F. Diazepam administration prevents testosterone decrease and lipofuscin accumulation in testis of mouse exposed to chronic noise stress. Andrologia 2006; 38:159-65. [PMID: 16961568 DOI: 10.1111/j.1439-0272.2006.00732.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Lipofuscin is an autofluorescent and undegradable material, which accumulates in tissues during ageing and under different types of stress. Among these, oxidative stress represents a major trigger for lipofuscin formation. However, prolonged noise exposure is also an effective stressful stimuli. Diazepam may inhibit lipofuscinogenesis in liver and prevent the noise-induced reduction of the steroidogenesis in the adrenal gland. The aim of the study was to ascertain whether chronic noise exposure causes lipofuscin accumulation in mouse testis, and to evaluate the effects of diazepam administration. Eight-week old mice were either exposed for 6 weeks (6 h day(-1)) to white-noise (group A), or received diazepam (3 mg kg(-1), i.p.) before noise exposures (group B), while a further group was used as control (group C). Light fluorescence and transmission electron microscopy revealed lipofuscin in large amounts in the Leydig cells in mice of group A, which concomitantly had low serum testosterone levels; pre-treatment with diazepam occluded both effects. The present study indicates that: (i) chronic noise exposure causes lipofuscin accumulation at the level of the Leydig cells and a decrease in testosterone; (ii) all these effects are suppressed by pre-treatment with diazepam. As the Leydig cells represent the only cellular type of the interstitial testicular tissue having peripheral benzodiazepine receptors, these results could be explained by the capacity of the peripheral benzodiazepine receptors to prevent reactive oxygen species damage and to increase the resistance of these cells to oxidative stress.
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Affiliation(s)
- R Ruffoli
- Dipartimento di Morfologia Umana e Biologia Applicata, Medicina del lavoro, Università di Pisa, Pisa, Italy.
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Brady NR, Hamacher-Brady A, Westerhoff HV, Gottlieb RA. A wave of reactive oxygen species (ROS)-induced ROS release in a sea of excitable mitochondria. Antioxid Redox Signal 2006; 8:1651-65. [PMID: 16987019 DOI: 10.1089/ars.2006.8.1651] [Citation(s) in RCA: 138] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Once considered simply as the main source of ATP, mitochondria are now implicated in the control of many additional aspects of cell physiology, such as calcium signaling, and pathology, as in injury incurred on ischemia and subsequent reperfusion (I/R). Mitochondrial respiration is ordinarily accompanied by low-level ROS production, but they can respond to elevated ROS concentrations by increasing their own ROS production, a phenomenon termed ROS-induced ROS release (RIRR). Two modes of RIRR have been described. In the first mode of RIRR, enhanced ROS leads to mitochondrial depolarization via activation of the MPTP, yielding a short-lived burst of ROS originating from the mitochondrial electron transport chain (ETC). The second mode of RIRR is MPTP independent but is regulated by the mitochondrial benzodiazepine receptor (mBzR). Increased ROS in the mitochondrion triggers opening of the inner mitochondrial membrane anion channel (IMAC), resulting in a brief increase in ETC-derived ROS. Both modes of RIRR have been shown to transmit localized mitochondrial perturbations throughout the cardiac cell in the form of oscillations or waves but are kinetically distinct and may involve different ROS that serve as second messengers. In this review, we discuss the mechanisms of these different modes of RIRR.
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Affiliation(s)
- Nathan R Brady
- Department of Molecular and Experimental Medicine, The Scripps Research Institute, La Jolla, California 92037, USA
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