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Bréhat J, Issop L, Morin D. History of Tspo deletion and induction in vivo: Phenotypic outcomes under physiological and pathological situations. Biochimie 2024; 224:80-90. [PMID: 38432291 DOI: 10.1016/j.biochi.2024.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/23/2024] [Accepted: 03/01/2024] [Indexed: 03/05/2024]
Abstract
The mitochondrial translocator protein (TSPO) is an outer mitochondrial protein membrane with high affinity for cholesterol. It is expressed in most tissues but is more particularly enriched in steroidogenic tissues. TSPO is involved in various biological mechanisms and TSPO regulation has been related to several diseases. However, despite a considerable number of published studies interested in TSPO over the past forty years, the precise function of the protein remains obscure. Most of the functions attributed to TSPO have been identified using pharmacological ligands of this protein, leading to much debate about the accuracy of these findings. In addition, research on the physiological role of TSPO has been hampered by the lack of in vivo deletion models. Studies to perform genetic deletion of Tspo in animal models have long been unsuccessful, which led to the conclusions that the deletion was deleterious and the gene essential to life. During the last decades, thanks to the significant technical advances allowing genome modification, several models of animal genetically modified for TSPO have been developed. These models have modified our view regarding TSPO and profoundly improved our fundamental knowledge on this protein. However, to date, they did not allow to elucidate the precise molecular function of TSPO and numerous questions persist concerning the physiological role of TSPO and its future as a therapeutic target. This article chronologically reviews the development of deletion and induction models of TSPO.
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Affiliation(s)
- Juliette Bréhat
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France
| | - Leeyah Issop
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France
| | - Didier Morin
- INSERM U955-IMRB, Team Ghaleh, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France.
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2
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Riebel M, Brunner LM, Nothdurfter C, Wein S, Schwarzbach J, Liere P, Schumacher M, Rupprecht R. Neurosteroids and translocator protein 18 kDa (TSPO) ligands as novel treatment options in depression. Eur Arch Psychiatry Clin Neurosci 2024:10.1007/s00406-024-01843-7. [PMID: 38976049 DOI: 10.1007/s00406-024-01843-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 06/06/2024] [Indexed: 07/09/2024]
Abstract
Recently, the gamma-aminobutyric acid (GABA) system has come into focus for the treatment of anxiety, postpartum depression, and major depressive disorder. Endogenous 3α-reduced steroids such as allopregnanolone are potent positive allosteric modulators of GABAA receptors and have been known for decades. Current industry developments and first approvals by the U.S. food and drug administration (FDA) for the treatment of postpartum depression with exogenous analogues of these steroids represent a major step forward in the field. 3α-reduced steroids target both synaptic and extrasynaptic GABAA receptors, unlike benzodiazepines, which bind to synaptic receptors. The first FDA-approved 3α-reduced steroid for postpartum depression is brexanolone, an intravenous formulation of allopregnanolone. It has been shown to provide rapid relief of depressive symptoms. An orally available 3α-reduced steroid is zuranolone, which also received FDA approval in 2023 for the treatment of postpartum depression. Although a number of studies have been conducted, the efficacy data were not sufficient to achieve approval of zuranolone in major depressive disorder by the FDA in 2023. The most prominent side effects of these 3α-reduced steroids are somnolence, dizziness and headache. In addition to the issue of efficacy, it should be noted that current data limit the use of these compounds to two weeks. An alternative to exogenous 3α-reduced steroids may be the use of substances that induce endogenous neurosteroidogenesis, such as the translocator protein 18 kDa (TSPO) ligand etifoxine. TSPO has been extensively studied for its role in steroidogenesis, in addition to other functions such as anti-inflammatory and neuroregenerative properties. Currently, etifoxine is the only clinically available TSPO ligand in France for the treatment of anxiety disorders. Studies are underway to evaluate its antidepressant potential. Hopefully, neurosteroid research will lead to the development of fast-acting antidepressants.
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Affiliation(s)
- Marco Riebel
- Department of Psychiatry and Psychotherapy, University Regensburg, Universitätsstrasse 84, 93053, Regensburg, Germany.
| | - Lisa-Marie Brunner
- Department of Psychiatry and Psychotherapy, University Regensburg, Universitätsstrasse 84, 93053, Regensburg, Germany
| | - Caroline Nothdurfter
- Department of Psychiatry and Psychotherapy, University Regensburg, Universitätsstrasse 84, 93053, Regensburg, Germany
| | - Simon Wein
- Department of Psychiatry and Psychotherapy, University Regensburg, Universitätsstrasse 84, 93053, Regensburg, Germany
| | - Jens Schwarzbach
- Department of Psychiatry and Psychotherapy, University Regensburg, Universitätsstrasse 84, 93053, Regensburg, Germany
| | - Philippe Liere
- U1195 Inserm and University Paris-Saclay, Le Kremlin-Bicêtre, Paris, 94276, France
| | - Michael Schumacher
- U1195 Inserm and University Paris-Saclay, Le Kremlin-Bicêtre, Paris, 94276, France
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University Regensburg, Universitätsstrasse 84, 93053, Regensburg, Germany
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El Chemali L, Boutary S, Liu S, Liu GJ, Middleton RJ, Banati RB, Bahrenberg G, Rupprecht R, Schumacher M, Massaad-Massade L. GRT-X Stimulates Dorsal Root Ganglia Axonal Growth in Culture via TSPO and Kv7.2/3 Potassium Channel Activation. Int J Mol Sci 2024; 25:7327. [PMID: 39000434 PMCID: PMC11242890 DOI: 10.3390/ijms25137327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2024] [Revised: 06/27/2024] [Accepted: 06/30/2024] [Indexed: 07/16/2024] Open
Abstract
GRT-X, which targets both the mitochondrial translocator protein (TSPO) and the Kv7.2/3 (KCNQ2/3) potassium channels, has been shown to efficiently promote recovery from cervical spine injury. In the present work, we investigate the role of GRT-X and its two targets in the axonal growth of dorsal root ganglion (DRG) neurons. Neurite outgrowth was quantified in DRG explant cultures prepared from wild-type C57BL6/J and TSPO-KO mice. TSPO was pharmacologically targeted with the agonist XBD173 and the Kv7 channels with the activator ICA-27243 and the inhibitor XE991. GRT-X efficiently stimulated DRG axonal growth at 4 and 8 days after its single administration. XBD173 also promoted axonal elongation, but only after 8 days and its repeated administration. In contrast, both ICA27243 and XE991 tended to decrease axonal elongation. In dissociated DRG neuron/Schwann cell co-cultures, GRT-X upregulated the expression of genes associated with axonal growth and myelination. In the TSPO-KO DRG cultures, the stimulatory effect of GRT-X on axonal growth was completely lost. However, GRT-X and XBD173 activated neuronal and Schwann cell gene expression after TSPO knockout, indicating the presence of additional targets warranting further investigation. These findings uncover a key role of the dual mode of action of GRT-X in the axonal elongation of DRG neurons.
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Affiliation(s)
- Léa El Chemali
- Maladies et Hormones du Système Nerveux, Inserm, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France
| | - Suzan Boutary
- Maladies et Hormones du Système Nerveux, Inserm, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France
| | - Song Liu
- Maladies et Hormones du Système Nerveux, Inserm, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France
| | - Guo-Jun Liu
- Australian Nuclear Science and Technology Organisation (ANSTO), Kirrawee, NSW 2232, Australia
- Faculty of Medicine and Health, University of Sydney, Camperdown, NSW 2006, Australia
| | - Ryan J Middleton
- Australian Nuclear Science and Technology Organisation (ANSTO), Kirrawee, NSW 2232, Australia
| | - Richard B Banati
- Faculty of Medicine and Health, University of Sydney, Camperdown, NSW 2006, Australia
| | - Gregor Bahrenberg
- Global Preclinical R&D, Grünenthal Innovation, Grünenthal GmbH, Zieglerstraße 6, D-52078 Aachen, Germany
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, D-93053 Regensburg, Germany
| | - Michael Schumacher
- Maladies et Hormones du Système Nerveux, Inserm, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France
| | - Liliane Massaad-Massade
- Maladies et Hormones du Système Nerveux, Inserm, Université Paris-Saclay, 94276 Le Kremlin-Bicêtre, France
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Kalakh S, Mouihate A. The Effects of Neuroactive Steroids on Myelin in Health and Disease. Med Princ Pract 2024; 33:198-214. [PMID: 38350432 PMCID: PMC11175611 DOI: 10.1159/000537794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 02/12/2024] [Indexed: 02/15/2024] Open
Abstract
Myelin plays a pivotal role in the efficient transmission of nerve impulses. Disruptions in myelin integrity are associated with numerous neurological disorders, including multiple sclerosis. In the central nervous system (CNS), myelin is formed by oligodendrocytes. Remyelination refers to the re-formation of the damaged myelin sheath by newly formed oligodendrocytes. Steroids have gained attention for their potential modulatory effects on myelin in both health and disease. Steroids are traditionally associated with endocrine functions, but their local synthesis within the nervous system has generated significant interest. The term "neuroactive steroids" refers to steroids that can act on cells of the nervous system. In the healthy state, neuroactive steroids promote myelin formation, maintenance, and repair by enhancing oligodendrocyte differentiation and maturation. In pathological conditions, such as demyelination injury, multiple neuroactive steroids have shown promise in promoting remyelination. Understanding the effects of neuroactive steroids on myelin could lead to novel therapeutic approaches for demyelinating diseases and neurodegenerative disorders. This review highlights the potential therapeutic significance of neuroactive steroids in myelin-related health and diseases. We review the synthesis of steroids by neurons and glial cells and discuss the roles of neuroactive steroids on myelin structure and function in health and disease. We emphasize the potential promyelinating effects of the varying levels of neuroactive steroids during different female physiological states such as the menstrual cycle, pregnancy, lactation, and postmenopause.
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Affiliation(s)
- Samah Kalakh
- Department of Physiology, College of Medicine, Kuwait University, Kuwait City, Kuwait
- School of Engineering and Computing, American International University, Kuwait City, Kuwait
| | - Abdeslam Mouihate
- Department of Physiology, College of Medicine, Kuwait University, Kuwait City, Kuwait
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Vallée M. Advances in steroid research from the pioneering neurosteroid concept to metabolomics: New insights into pregnenolone function. Front Neuroendocrinol 2024; 72:101113. [PMID: 37993022 DOI: 10.1016/j.yfrne.2023.101113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 11/13/2023] [Accepted: 11/19/2023] [Indexed: 11/24/2023]
Abstract
Advances in neuroendocrinology have led to major discoveries since the 19th century, identifying adaptive loops for maintaining homeostasis. One of the most remarkable discoveries was the concept of neurosteroids, according to which the brain is not only a target but also a source of steroid production. The identification of new membrane steroid targets now underpins the neuromodulatory effects of neurosteroids such as pregnenolone, which is involved in functions mediated by the GPCR CB1 receptor. Structural analysis of steroids is a key feature of their interactions with the phospholipid membrane, receptors and resulting activity. Therefore, mass spectrometry-based methods have been developed to elucidate the metabolic pathways of steroids, the ultimate approach being metabolomics, which allows the identification of a large number of metabolites in a single sample. This approach should enable us to make progress in understanding the role of neurosteroids in the functioning of physiological and pathological processes.
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Affiliation(s)
- Monique Vallée
- University Bordeaux, INSERM, Neurocentre Magendie, U1215, F-33000 Bordeaux, France.
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Tuominen S, Nissi L, Kukkula A, Routila J, Huusko T, Leivo I, Minn H, Irjala H, Löyttyniemi E, Ventelä S, Sundvall M, Grönroos TJ. TSPO is a potential independent prognostic factor associated with cellular respiration and p16 in head and neck squamous cell carcinoma. Front Oncol 2023; 13:1298333. [PMID: 38162485 PMCID: PMC10755888 DOI: 10.3389/fonc.2023.1298333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 11/27/2023] [Indexed: 01/03/2024] Open
Abstract
Background Treatment resistance and relapse are common problems in head and neck squamous cell carcinoma (HNSCC). Except for p16, no clinically accepted prognostic biomarkers are available for HNSCC. New biomarkers predictive of recurrence and survival are crucial for optimal treatment planning and patient outcome. High translocator protein (TSPO) levels have been associated with poor survival in cancer, but the role of TSPO has not been extensively evaluated in HNSCC. Materials and methods TSPO expression was determined in a large population-based tissue microarray cohort including 611 patients with HNSCC and evaluated for survival in several clinicopathological subgroups. A TCGA HNSCC cohort was used to further analyze the role of TSPO in HNSCC. Results TSPO expression was downregulated in more aggressive tumors. Low TSPO expression associated with worse 5-year survival and was an independent prognostic factor for disease-specific survival. Subgroup analyses showed that low TSPO expression associated with worse survival particularly in p16-positive oropharyngeal cancer. In silico analyses supported the prognostic role of TSPO. Cellular respiration had the highest significance in pathway analyses for genes expressed positively with TSPO. Conclusion Decreased TSPO expression associates with poor prognosis in HNSCC. TSPO is a prognostic biomarker in HNSCC to potentially guide treatment stratification especially in p16-positive oropharyngeal cancer.
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Affiliation(s)
- Sanni Tuominen
- Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Turku, Finland
- Cancer Research Unit, Institute of Biomedicine, University of Turku, Turku, Finland
- FICAN West Cancer Research Laboratory, Turku University Hospital and University of Turku, Turku, Finland
- Medicity Research Laboratory, Faculty of Medicine, University of Turku, Turku, Finland
| | - Linda Nissi
- Department of Clinical Oncology, Turku University Hospital and University of Turku, Turku, Finland
| | - Antti Kukkula
- Cancer Research Unit, Institute of Biomedicine, University of Turku, Turku, Finland
- FICAN West Cancer Research Laboratory, Turku University Hospital and University of Turku, Turku, Finland
| | - Johannes Routila
- Department of Otorhinolaryngology – Head and Neck Surgery, Turku University Hospital and University of Turku, Turku, Finland
| | - Teemu Huusko
- Department of Otorhinolaryngology – Head and Neck Surgery, Turku University Hospital and University of Turku, Turku, Finland
| | - Ilmo Leivo
- Department of Pathology, Turku University Hospital and University of Turku, Turku, Finland
| | - Heikki Minn
- Department of Clinical Oncology, Turku University Hospital and University of Turku, Turku, Finland
| | - Heikki Irjala
- Department of Otorhinolaryngology – Head and Neck Surgery, Turku University Hospital and University of Turku, Turku, Finland
| | - Eliisa Löyttyniemi
- Department of Biostatistics, Turku University Hospital and University of Turku, Turku, Finland
| | - Sami Ventelä
- Department of Otorhinolaryngology – Head and Neck Surgery, Turku University Hospital and University of Turku, Turku, Finland
| | - Maria Sundvall
- Cancer Research Unit, Institute of Biomedicine, University of Turku, Turku, Finland
- FICAN West Cancer Research Laboratory, Turku University Hospital and University of Turku, Turku, Finland
- Department of Clinical Oncology, Turku University Hospital and University of Turku, Turku, Finland
| | - Tove J. Grönroos
- Preclinical Imaging Laboratory, Turku PET Centre, University of Turku, Turku, Finland
- Medicity Research Laboratory, Faculty of Medicine, University of Turku, Turku, Finland
- Department of Clinical Oncology, Turku University Hospital and University of Turku, Turku, Finland
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Rodriguez-Lopez A, Torres-Paniagua AM, Acero G, Díaz G, Gevorkian G. Increased TSPO expression, pyroglutamate-modified amyloid beta (AβN3(pE)) accumulation and transient clustering of microglia in the thalamus of Tg-SwDI mice. J Neuroimmunol 2023; 382:578150. [PMID: 37467699 DOI: 10.1016/j.jneuroim.2023.578150] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/07/2023] [Accepted: 07/09/2023] [Indexed: 07/21/2023]
Abstract
Epidemiological studies showed that Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA) frequently co-occur; however, the precise mechanism is not well understood. A unique animal model (Tg-SwDI mice) was developed to investigate the early-onset and robust accumulation of both parenchymal and vascular Aβ in the brain. Tg-SwDI mice have been extensively used to study the mechanisms of cerebrovascular dysfunction, neuroinflammation, neurodegeneration, and cognitive decline observed in AD/CAA patients and to design biomarkers and therapeutic strategies. In the present study, we documented interesting new features in the thalamus of Tg-SwDI mice: 1) a sharp increase in the expression of ionized calcium-binding adapter molecule 1 (Iba-1) in microglia in 6-month-old animals; 2) microglia clustering at six months that disappeared in old animals; 3) N-truncated/modified AβN3(pE) peptide in 9-month-old female and 12-month-old male mice; 4) an age-dependent increase in translocator protein (TSPO) expression. These findings reinforce the versatility of this model for studying multiple pathological issues involved in AD and CAA.
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Affiliation(s)
- Adrian Rodriguez-Lopez
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70228, Cuidad Universitaria, CDMX, CP 04510, Mexico
| | - Alicia M Torres-Paniagua
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70228, Cuidad Universitaria, CDMX, CP 04510, Mexico
| | - Gonzalo Acero
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70228, Cuidad Universitaria, CDMX, CP 04510, Mexico
| | - Georgina Díaz
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70228, Cuidad Universitaria, CDMX, CP 04510, Mexico
| | - Goar Gevorkian
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), Apartado Postal 70228, Cuidad Universitaria, CDMX, CP 04510, Mexico.
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Sidhu SK, Mishra S. A cholesterol-centric outlook on steroidogenesis. VITAMINS AND HORMONES 2023; 124:405-428. [PMID: 38408806 DOI: 10.1016/bs.vh.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Cholesterol, an essential and versatile lipid, is the precursor substrate for the biosynthesis of steroid hormones, and a key structural and functional component of organelle membranes in eukaryotic cells. Consequently, the framework of steroidogenesis across main steroidogenic cell types is built around cholesterol, including its cellular uptake, mobilization from intracellular storage, and finally, its transport to the mitochondria where steroidogenesis begins. This setup, which is controlled by different trophic hormones in their respective target tissues, allows steroidogenic cells to meet their steroidogenic need of cholesterol effectively without impinging on the basic need for organelle membranes and their functions. However, our understanding of the basal steroidogenesis (i.e., independent of trophic hormone stimulation), which is a cell-intrinsic trait, remains poor. Particularly, the role that cholesterol itself plays in the regulation of steroidogenic factors and events in steroid hormone-producing cells remains largely unexplored. This is likely because of challenges in selectively targeting the steroidogenic intracellular cholesterol pool in studies. New evidence suggests that cholesterol plays a role in steroidogenesis. These new findings have created new opportunities to advance our understanding in this field. In this book chapter, we will provide a cholesterol-centric view on steroidogenesis and emphasize the importance of the interplay between cholesterol and the mitochondria in steroidogenic cells. Moreover, we will discuss a novel mitochondrial player, prohibitin-1, in this context. The overall goal is to provide a stimulating perspective on cholesterol as an important regulator of steroidogenesis (i.e., more than just a substrate for steroid hormones) and present the mitochondria as a potential cell-intrinsic factor in regulating steroidogenic cholesterol homeostasis.
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Affiliation(s)
- Simarjit Kaur Sidhu
- Department of Physiology & Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Suresh Mishra
- Department of Physiology & Pathophysiology, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada; Department of Internal Medicine, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada.
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