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Cheung G, Lin YC, Papadopoulos V. Translocator protein in the rise and fall of central nervous system neurons. Front Cell Neurosci 2023; 17:1210205. [PMID: 37416505 PMCID: PMC10322222 DOI: 10.3389/fncel.2023.1210205] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 06/07/2023] [Indexed: 07/08/2023] Open
Abstract
Translocator protein (TSPO), a 18 kDa protein found in the outer mitochondrial membrane, has historically been associated with the transport of cholesterol in highly steroidogenic tissues though it is found in all cells throughout the mammalian body. TSPO has also been associated with molecular transport, oxidative stress, apoptosis, and energy metabolism. TSPO levels are typically low in the central nervous system (CNS), but a significant upregulation is observed in activated microglia during neuroinflammation. However, there are also a few specific regions that have been reported to have higher TSPO levels than the rest of the brain under normal conditions. These include the dentate gyrus of the hippocampus, the olfactory bulb, the subventricular zone, the choroid plexus, and the cerebellum. These areas are also all associated with adult neurogenesis, yet there is no explanation of TSPO's function in these cells. Current studies have investigated the role of TSPO in microglia during neuron degeneration, but TSPO's role in the rest of the neuron lifecycle remains to be elucidated. This review aims to discuss the known functions of TSPO and its potential role in the lifecycle of neurons within the CNS.
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Coppin E, Zhang X, Ohayon L, Johny E, Dasari A, Zheng KH, Stiekema L, Cifuentes-Pagano E, Pagano PJ, Chaparala S, Stroes ES, Dutta P. Peripheral Ischemia Imprints Epigenetic Changes in Hematopoietic Stem Cells to Propagate Inflammation and Atherosclerosis. Arterioscler Thromb Vasc Biol 2023; 43:889-906. [PMID: 36891902 PMCID: PMC10213134 DOI: 10.1161/atvbaha.123.318956] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 02/20/2023] [Indexed: 03/10/2023]
Abstract
BACKGROUND Peripheral ischemia caused by peripheral artery disease is associated with systemic inflammation, which may aggravate underlying comorbidities such as atherosclerosis and heart failure. However, the mechanisms of increased inflammation and inflammatory cell production in patients with peripheral artery disease remain poorly understood. METHODS We used peripheral blood collected from patients with peripheral artery disease and performed hind limb ischemia (HI) in Apoe-/- mice fed a Western diet and C57BL/6J mice with a standard laboratory diet. Bulk and single-cell RNA sequencing analysis, whole-mount microscopy, and flow cytometry were performed to analyze hematopoietic stem and progenitor cell (HSPC) proliferation, differentiation, and relocation. RESULTS We observed augmented numbers of leukocytes in the blood of patients with peripheral artery disease and Apoe-/- mice with HI. RNA sequencing and whole-mount imaging of the bone marrow revealed HSPC migration into the vascular niche from the osteoblastic niche and their exaggerated proliferation and differentiation. Single-cell RNA sequencing demonstrated alterations in the genes responsible for inflammation, myeloid cell mobilization, and HSPC differentiation after HI. Heightened inflammation in Apoe-/- mice after HI aggravated atherosclerosis. Surprisingly, bone marrow HSPCs expressed higher amounts of the receptors for IL (interleukin)-1 and IL-3 after HI. Concomitantly, the promoters of Il1r1 and Il3rb had augmented H3K4me3 and H3K27ac marks after HI. Genetic and pharmacological inhibition of these receptors resulted in suppressed HSPC proliferation, reduced leukocyte production, and ameliorated atherosclerosis. CONCLUSIONS Our findings demonstrate increased inflammation, HSPC abundance in the vascular niches of the bone marrow, and elevated IL-3Rb and IL-1R1 (IL-1 receptor 1) expression in HSPC following HI. Furthermore, the IL-3Rb and IL-1R1 signaling plays a pivotal role in HSPC proliferation, leukocyte abundance, and atherosclerosis aggravation after HI.
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Affiliation(s)
- Emilie Coppin
- Regeneration in Hematopoiesis, Institute for Immunology, TU Dresden, Dresden, Germany
- Immunology of Aging, Leibniz Institute on Aging – Fritz Lipmann Institute, Jena, Germany
| | - Xinyi Zhang
- Department of Cardiology, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou 310009, China
| | - Lee Ohayon
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Ebin Johny
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Ankush Dasari
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Kang H. Zheng
- Department of Vascular Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Lotte Stiekema
- Department of Vascular Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Eugenia Cifuentes-Pagano
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Patrick J. Pagano
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA
| | - Srilakshmi Chaparala
- Health Sciences Library System, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Erik S. Stroes
- Department of Vascular Medicine, Amsterdam Cardiovascular Sciences, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Partha Dutta
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Division of Cardiology, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Department of Immunology, University of Pittsburgh, Pittsburgh, PA 15213, USA
- Pittsburgh VA Medical Center-University Drive, University Drive C, Pittsburgh, PA, 15213
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3
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Angeloni E, Germelli L, Marchetti L, Da Pozzo E, Tremolanti C, Wetzel CH, Baglini E, Taliani S, Da Settimo F, Martini C, Costa B. The human microglial surveillant phenotype is preserved by de novo neurosteroidogenesis through the control of cholesterol homeostasis: Crucial role of 18 kDa Translocator Protein. Biochim Biophys Acta Mol Basis Dis 2023; 1869:166751. [PMID: 37169037 DOI: 10.1016/j.bbadis.2023.166751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/13/2023]
Abstract
Neurodegenerative disease-associated microglia commonly exhibit harmful cholesterol accumulation that impairs their ability to resolve the neuroinflammatory response, contributing to disease onset and progression. Neurosteroids, whose levels have been often found significantly altered in brain diseases, are the most potent endogenous anti-inflammatory molecules exerting beneficial effects on activities of brain cells, including microglia. For the first time, the impact of neurosteroidogenesis on cholesterol homeostasis for the immune surveillance phenotype maintenance was investigated in a human microglia in vitro model. To enhance and inhibit neurosteroidogenesis, pharmacological stimulation and knock-down of 18 kDa Translocator Protein (TSPO), which is involved in the neurosteroidogenesis rate-limiting step, were used as experimental approaches, respectively. The obtained results point to an essential autocrine control of neurosteroidogenesis in orchestrating cholesterol trafficking in human microglia. TSPO pharmacological stimulation ensured cholesterol turnover by strengthening cholesterol efflux systems and preserving healthy immune surveillant phenotype. Conversely, TSPO knock-down induced an impairment of the controlled interplay among cholesterol synthesis, efflux, and metabolism mechanisms, leading to an excessive cholesterol accumulation and acquisition of a chronically activated dysfunctional phenotype. In this model, the exogenous neurosteroid administration restored proper the cholesterol clearance. The TSPO ability in promoting native neurosteroidogenesis opens the way to restore cholesterol homeostasis, and thus to maintain microglia proper functionality for the treatment of neuroinflammation-related brain diseases.
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Affiliation(s)
- Elisa Angeloni
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy.
| | - Lorenzo Germelli
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy.
| | - Laura Marchetti
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy; Center for Instrument Sharing University of Pisa (CISUP), Lungarno Pacinotti, 43/44, 56126 Pisa, Italy.
| | - Eleonora Da Pozzo
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy; Center for Instrument Sharing University of Pisa (CISUP), Lungarno Pacinotti, 43/44, 56126 Pisa, Italy.
| | - Chiara Tremolanti
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy.
| | - Christian H Wetzel
- Department of Psychiatry and Psychotherapy, Molecular Neurosciences, University of Regensburg, 93059 Regensburg, Germany.
| | - Emma Baglini
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy.
| | - Sabrina Taliani
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy.
| | - Federico Da Settimo
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy.
| | - Claudia Martini
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy.
| | - Barbara Costa
- Department of Pharmacy, University of Pisa, via Bonanno 6, 56126 Pisa, Italy; Center for Instrument Sharing University of Pisa (CISUP), Lungarno Pacinotti, 43/44, 56126 Pisa, Italy.
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4
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Garza S, Chen L, Galano M, Cheung G, Sottas C, Li L, Li Y, Zirkin BR, Papadopoulos V. Mitochondrial dynamics, Leydig cell function, and age-related testosterone deficiency. FASEB J 2022; 36:e22637. [PMID: 36349989 DOI: 10.1096/fj.202201026r] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 10/04/2022] [Accepted: 10/20/2022] [Indexed: 11/11/2022]
Abstract
The mitochondrial translocator protein (18 kDa; TSPO) is a high-affinity cholesterol-binding protein that is an integral component of the cholesterol trafficking scaffold responsible for determining the rate of cholesterol import into the mitochondria for steroid biosynthesis. Previous studies have shown that TSPO declines in aging Leydig cells (LCs) and that its decline is associated with depressed circulating testosterone levels in aging rats. However, TSPO's role in the mechanistic decline in LC function is not fully understood. To address the role of TSPO depletion in LC function, we first examined mitochondrial quality in Tspo knockout mouse tumor MA-10 nG1 LCs compared to wild-type MA-10 cells. Tspo deletion caused a disruption in mitochondrial function and membrane dynamics. Increasing mitochondrial fusion via treatment with the mitochondrial fusion promoter M1 or by optic atrophy 1 (OPA1) overexpression resulted in the restoration of mitochondrial function and mitochondrial morphology as well as in steroid formation in TSPO-depleted nG1 LCs. LCs isolated from aged rats form less testosterone than LCs isolated from young rats. Treatment of aging LCs with M1 improved mitochondrial function and increased androgen formation, suggesting that aging LC dysfunction may stem from compromised mitochondrial dynamics caused by the age-dependent LC TSPO decline. These results, taken together, suggest that maintaining or enhancing mitochondrial fusion may provide therapeutic strategies to maintain or restore testosterone levels with aging.
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Affiliation(s)
- Samuel Garza
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Liting Chen
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Melanie Galano
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Garett Cheung
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Chantal Sottas
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Lu Li
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Yuchang Li
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
| | - Barry R Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
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5
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Yue YY, Wang YC, Liao ZX, Hu FY, Liu QY, Dong J, Zhong M, Chen MH, Pan YM, Zhong H, Shang J. Peripheral benzodiazepine receptor TSPO needs to be reconsidered before using as a drug target for a pigmentary disorder. FASEB J 2022; 36:e22454. [PMID: 35839067 DOI: 10.1096/fj.202101746rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 06/19/2022] [Accepted: 07/06/2022] [Indexed: 11/11/2022]
Abstract
The peripheral benzodiazepine receptor (TSPO/PBR) is highly conserved among different species but with perplexing biochemical functions. Multiple ligands of TSPO show commendable regulatory activities in lots of biological functions, such as neuro-protection, cholesterol transport, and so on. These researches support that TSPO may be a potential target for disease treatment and drug development. Previous studies have shown that its ligands benzodiazepines show a satisfactory effect on melanogenic promotion. However, the potential application of TSPO in drug development for pigmentary disorder needs further investigation. In this study, we confirmed the melanogenesis induction of TSPO ligand, Ro5-4864 in mouse melanoma cell lines, human skin tissue, and zebrafish embryos by inducing melanin synthesis and melanosome transport. Molecular genetics and pharmacological studies showed that TSPO deficiency did not affect melanin production in B16F10 cells and zebrafish embryos, nor did it affect the melanin promotion effect of Ro5-4864. Whether or not TSPO exists, the expression of lots of melanogenesis-related proteins, such as TYR, TRP-1, DCT, Mlph, and Rab27 was upregulated with the Ro5-4864 administration. These results indicated that Ro5-4864 induces melanogenesis in a TSPO-independent manner, which is inconsistent with previous research. This research is a reminder that we need to be very careful during target validation in drug development.
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Affiliation(s)
- Yun-Yun Yue
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Yi-Chuan Wang
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Zi-Xian Liao
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Fang-Yuan Hu
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Qiu-Yan Liu
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jing Dong
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Min Zhong
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Ming-Han Chen
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Yu-Min Pan
- School of Chemistry and Pharmacy, Guangxi Normal University, Guilin, China
| | - Hui Zhong
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jing Shang
- School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China.,State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China.,Jiangsu Key Laboratory of TCM Evaluation and Translational Research, China Pharmaceutical University, Nanjing, China.,NMPA Key Laboratory for Research and Evaluation of Cosmetics, National Institutes for Food and Drug Control, Beijing, China
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6
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Nutma E, Ceyzériat K, Amor S, Tsartsalis S, Millet P, Owen DR, Papadopoulos V, Tournier BB. Cellular sources of TSPO expression in healthy and diseased brain. Eur J Nucl Med Mol Imaging 2021; 49:146-163. [PMID: 33433698 PMCID: PMC8712293 DOI: 10.1007/s00259-020-05166-2] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 12/13/2020] [Indexed: 12/11/2022]
Abstract
The 18 kDa translocator protein (TSPO) is a highly conserved protein located in the outer mitochondrial membrane. TSPO binding, as measured with positron emission tomography (PET), is considered an in vivo marker of neuroinflammation. Indeed, TSPO expression is altered in neurodegenerative, neuroinflammatory, and neuropsychiatric diseases. In PET studies, the TSPO signal is often viewed as a marker of microglial cell activity. However, there is little evidence in support of a microglia-specific TSPO expression. This review describes the cellular sources and functions of TSPO in animal models of disease and human studies, in health, and in central nervous system diseases. A discussion of methods of analysis and of quantification of TSPO is also presented. Overall, it appears that the alterations of TSPO binding, their cellular underpinnings, and the functional significance of such alterations depend on many factors, notably the pathology or the animal model under study, the disease stage, and the involved brain regions. Thus, further studies are needed to fully determine how changes in TSPO binding occur at the cellular level with the ultimate goal of revealing potential therapeutic pathways.
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Affiliation(s)
- Erik Nutma
- Department of Pathology, Amsterdam UMC, VUmc, Amsterdam, The Netherlands
| | - Kelly Ceyzériat
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Avenue de la Roseraie, 64, 1206, Geneva, Switzerland
- Division of Nuclear medicine and Molecular Imaging, University Hospitals of Geneva, Geneva, Switzerland
- Division of Radiation Oncology, Department of Oncology, University Hospitals of Geneva, Geneva, Switzerland
| | - Sandra Amor
- Department of Pathology, Amsterdam UMC, VUmc, Amsterdam, The Netherlands
- Centre for Neuroscience and Trauma, Blizard Institute, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Stergios Tsartsalis
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Avenue de la Roseraie, 64, 1206, Geneva, Switzerland
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Philippe Millet
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Avenue de la Roseraie, 64, 1206, Geneva, Switzerland
- Department of Psychiatry, University of Geneva, Geneva, Switzerland
| | - David R Owen
- Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Benjamin B Tournier
- Division of Adult Psychiatry, Department of Psychiatry, University Hospitals of Geneva, Avenue de la Roseraie, 64, 1206, Geneva, Switzerland.
- Department of Psychiatry, University of Geneva, Geneva, Switzerland.
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7
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Nguyen HT, Najih M, Martin LJ. The AP-1 family of transcription factors are important regulators of gene expression within Leydig cells. Endocrine 2021; 74:498-507. [PMID: 34599696 DOI: 10.1007/s12020-021-02888-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/16/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Members of the AP-1 family of transcription factors are immediate early genes being modulated by different extracellular signals. The aim of this review is to highlight the important roles of AP-1 members in transcriptional regulation of genes important for testicular Leydig cell function and male testosterone production. METHODS A search of the relevant literature was performed in Google Scholar and NCBI Pubmed for AP-1 members and Leydig cells. Additional information was accessed from references of relevant articles. Only primary data from original peer-reviewed articles was considered for this review. RESULTS Different signaling pathways important for Leydig cells' functions are involved in the regulation of the activity of AP-1 members. These transcription factors participate in the regulation of genes related to different biological processes important for Leydig cells. CONCLUSIONS We conclude that members of the AP-1 family of transcription factors play critical roles in the regulation of Leydig cell proliferation, steroidogenesis, and cell-to-cell communication.
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Affiliation(s)
- Ha Tuyen Nguyen
- Biology Department, Université de Moncton, Moncton, NB, E1A 3E9, Canada
| | - Mustapha Najih
- Biology Department, Université de Moncton, Moncton, NB, E1A 3E9, Canada
| | - Luc J Martin
- Biology Department, Université de Moncton, Moncton, NB, E1A 3E9, Canada.
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8
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Morrissey NA, Beall C, Ellacott KLJ. Absence of the mitochondrial translocator protein 18 kDa in mice does not affect body weight or food intake responses to altered energy availability. J Neuroendocrinol 2021; 33:e13027. [PMID: 34423477 DOI: 10.1111/jne.13027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 07/21/2021] [Accepted: 08/05/2021] [Indexed: 11/29/2022]
Abstract
Changes in mitochondrial function in a variety of cells/tissues are critical for orchestrating systemic energy homeostasis and are linked to the development of obesity and many of its comorbidities. The mitochondrial translocator protein of 18 kDa (TSPO) is expressed in organs throughout the body, including the brain, liver, adipose tissue, gonads and adrenal glands, where it is implicated in regulating steroidogenesis and cellular metabolism. Prior work from our group and others has shown that, in rodents, TSPO levels are altered in adipose tissue by obesity and that modulation of TSPO activity may impact systemic glucose homeostasis. Furthermore, in vitro studies in a variety of cell types have implicated TSPO in mediating cellular energetics and substrate utilisation. Although mice with germline global TSPO deficiency (TSPO-/- ) have no reported changes in body weight under standard husbandry conditions, we hypothesised that, given the roles of TSPO in regulating mitochondrial function and cellular metabolic flexibility, these animals may have alterations in their systemic response to altered energy availability, either nutritional excess or insufficiency. In agreement with published work, compared to wild-type (TSPO+/+ ) littermates, TSPO-/- mice of both sexes did not exhibit differences in body weight on standard chow. Furthermore, following a 12-hour overnight fast, there was no difference in weight loss or compensatory food intake during re-feeding. Five weeks of feeding a high-fat diet (HFD) did not reveal any impact of the absence of TSPO on body weight gain in either male or female mice. Basal blood glucose levels and glucose clearance in a glucose tolerance test were influenced by feeding a HFD diet but not by genotype. In conclusion, in the paradigms examined, germline global deletion of TSPO did not change the physiological response to deviations in systemic energy availability at the whole organism level.
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Affiliation(s)
- Nicole A Morrissey
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, College of Medicine & Health, University of Exeter, Exeter, UK
| | - Craig Beall
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, College of Medicine & Health, University of Exeter, Exeter, UK
| | - Kate L J Ellacott
- Neuroendocrine Research Group, Institute of Biomedical & Clinical Sciences, College of Medicine & Health, University of Exeter, Exeter, UK
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9
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Hiser C, Montgomery BL, Ferguson-Miller S. TSPO protein binding partners in bacteria, animals, and plants. J Bioenerg Biomembr 2021; 53:463-487. [PMID: 34191248 PMCID: PMC8243069 DOI: 10.1007/s10863-021-09905-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 06/12/2021] [Indexed: 12/11/2022]
Abstract
The ancient membrane protein TSPO is phylogenetically widespread from archaea and bacteria to insects, vertebrates, plants, and fungi. TSPO’s primary amino acid sequence is only modestly conserved between diverse species, although its five transmembrane helical structure appears mainly conserved. Its cellular location and orientation in membranes have been reported to vary between species and tissues, with implications for potential diverse binding partners and function. Most TSPO functions relate to stress-induced changes in metabolism, but in many cases it is unclear how TSPO itself functions—whether as a receptor, a sensor, a transporter, or a translocator. Much evidence suggests that TSPO acts indirectly by association with various protein binding partners or with endogenous or exogenous ligands. In this review, we focus on proteins that have most commonly been invoked as TSPO binding partners. We suggest that TSPO was originally a bacterial receptor/stress sensor associated with porphyrin binding as its most ancestral function and that it later developed additional stress-related roles in eukaryotes as its ability to bind new partners evolved.
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Affiliation(s)
- Carrie Hiser
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA. .,Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA.
| | - Beronda L Montgomery
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA.,Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA.,Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Shelagh Ferguson-Miller
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
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10
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Chung JY, Brown S, Chen H, Liu J, Papadopoulos V, Zirkin B. Effects of pharmacologically induced Leydig cell testosterone production on intratesticular testosterone and spermatogenesis†. Biol Reprod 2021; 102:489-498. [PMID: 31504200 DOI: 10.1093/biolre/ioz174] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/30/2019] [Accepted: 08/26/2019] [Indexed: 12/13/2022] Open
Abstract
The Leydig cells of the mammalian testis produce testosterone (T) in response to luteinizing hormone (LH). In rats and men with reduced serum T levels, T replacement therapy (TRT) will raise T levels, but typically with suppressive effects on sperm formation. The rate-determining step in T formation is the translocation of cholesterol to the inner mitochondrial membrane, mediated by protein-protein interactions of cytosolic and outer mitochondrial membrane proteins. Among the involved proteins is cholesterol-binding translocator protein (TSPO) (18 kDa TSPO). We hypothesized that in contrast to TRT, the administration of the TSPO agonist N,N-dihexyl-2-(4-fluorophenyl)indole-3-acetamide (FGIN-1-27), by stimulating the ability of the Leydig cells to produce T, would result in the elevation of serum T levels while maintaining intratesticular T concentration and therefore without suppression of spermatogenesis. Age-related reductions in both serum and intratesticular T levels were seen in old Brown Norway rats. Both exogenous T and FGIN-1-27 increased serum T levels. With exogenous T, serum LH and Leydig cell T formation were suppressed, and intratesticular T was reduced to below the concentration required to maintain spermatogenesis quantitatively. In contrast, FGIN-1-27 stimulated Leydig cell T formation, resulting in increased serum T without reductions in intratesticular T concentrations or in testicular sperm numbers. FGIN-1-27 also significantly increased serum and intratesticular T levels in rats made LH-deficient by treatment with the gonadotropin-releasing hormone antagonist cetrorelix. These results point to a possible approach to increasing serum T without negative effects on spermatogenesis, based upon stimulating T production by the Leydig cells themselves rather than administering T exogenously.
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Affiliation(s)
- Jin-Yong Chung
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Sean Brown
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Haolin Chen
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Department of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - June Liu
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Barry Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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Deletion of Mitochondrial Translocator Protein (TSPO) Gene Decreases Oxidative Retinal Pigment Epithelial Cell Death via Modulation of TRPM2 Channel. BIOLOGY 2021; 10:biology10050382. [PMID: 33924902 PMCID: PMC8145237 DOI: 10.3390/biology10050382] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/03/2021] [Accepted: 04/20/2021] [Indexed: 01/11/2023]
Abstract
Simple Summary 18 kDa mitochondrial translocator protein (TSPO) is a mitochondria protein of the cellular outer membrane in the mitochondria of several cells, including ARPE19 is TSPO. Accumulating evince indicates that the presence of TSPO participated the modulations of Ca2+ homeostasis and mitochondrial free reactive oxygen species (fROS) generation. The deletion of TSPO gene provides to study the action of TSPO on the levels of apoptosis, ADP-ribose (ADPR), mitochondria-fROS (Mito-fROS), and apoptosis via the stimulation of Ca2+ permeable channels in the models of cell culture. The stimulations of oxidative stress and ADPR induce the activation of TRPM2 in the ARPE19. For clarifying the involvement of TSPO in retinal human diseases, we used the ARPE19 human cell culture model. The current results demonstrated that the deletion of TSPO induces the regulation of TRPM2 in the TSPO gene knockout ARPE19 (ARPE19-KO) In fact, the present results show that the presence of TSPO increased the upregulations of apoptosis and mitochondria oxidative cytotoxicity values via stimulation of TRPM2 in the ARPE19. Nevertheless, the blockages of PARP-1 (PJ34 and DPQ) and TRPM2 (2APB and ACA) downregulated the values of cell death and oxidative cytotoxicity in the ARPE19. In summary, present results clearly demonstrate that the deletion of TSPO decreases mitochondrial oxidative cytotoxicity-mediated cell death via the modulation of TRPM2 in the ARPE19. Abstract The current results indicated the possible protective actions of 18 kDa mitochondrial translocator protein (TSPO) deletion on TRPM2 stimulation, mitochondrial free ROS (Mito-fROS) and apoptotic harmful actions in the cells of adult retinal pigment epithelial19 (ARPE19). There was a direct relationship between TSPO and the disease of age-related macular degeneration. The nature of TSPO implicates upregulation of Mito-fROS and apoptosis via the activation of Ca2+ channels in ARPE19, although deletion of TSPO gene downregulates the activation. The decrease of oxidative cytotoxicity and apoptosis might induce in TSPO gene deleted cells by the inhibition of Mito-fROS and PARP-1 activation-induced TRPM2 cation channel activation. The ARPE19 cells were divided into two main groups as TSPO expressing (ARPE19) and non-expressing cells (ARPE19-KO). The levels of caspase -3 (Casp -3), caspase -9 (Casp -9), apoptosis, Mito-fROS, TRPM2 current and intracellular free Ca2+ were upregulated in the ARPE19 by the stimulations of H2O2 and ADP-ribose, although their levels were downregulated in the cells by the modulators of PARP-1 (DPQ and PJ34), TRPM2 (ACA and 2APB) and glutathione. However, the H2O2 and ADP-ribose-mediated increases were not observed in the ARPE19-KO. The expression levels of Bax, Casp -3, Casp -9 and PARP-1 were higher in the ARPE19 group as compared to the ARPE19-KO group. In summary, current results confirmed that TRPM2-mediated cell death and oxidative cytotoxicity in the ARPE19 cells were occurred by the presence of TSPO. The deletion of TSPO may be considered as a therapeutic way to TRPM2 activation-mediated retinal oxidative injury.
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De novo Neurosteroidogenesis in Human Microglia: Involvement of the 18 kDa Translocator Protein. Int J Mol Sci 2021; 22:ijms22063115. [PMID: 33803741 PMCID: PMC8003294 DOI: 10.3390/ijms22063115] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/06/2021] [Accepted: 03/15/2021] [Indexed: 12/14/2022] Open
Abstract
Neuroactive steroids are potent modulators of microglial functions and are capable of counteracting their excessive reactivity. This action has mainly been ascribed to neuroactive steroids released from other sources, as microglia have been defined unable to produce neurosteroids de novo. Unexpectedly, immortalized murine microglia recently exhibited this de novo biosynthesis; herein, de novo neurosteroidogenesis was characterized in immortalized human microglia. The results demonstrated that C20 and HMC3 microglial cells constitutively express members of the neurosteroidogenesis multiprotein machinery-in particular, the transduceosome members StAR and TSPO, and the enzyme CYP11A1. Moreover, both cell lines produce pregnenolone and transcriptionally express the enzymes involved in neurosteroidogenesis. The high TSPO expression levels observed in microglia prompted us to assess its role in de novo neurosteroidogenesis. TSPO siRNA and TSPO synthetic ligand treatments were used to reduce and prompt TSPO function, respectively. The TSPO expression downregulation compromised the de novo neurosteroidogenesis and led to an increase in StAR expression, probably as a compensatory mechanism. The pharmacological TSPO stimulation the de novo neurosteroidogenesis improved in turn the neurosteroid-mediated release of Brain-Derived Neurotrophic Factor. In conclusion, these results demonstrated that de novo neurosteroidogenesis occurs in human microglia, unravelling a new mechanism potentially useful for future therapeutic purposes.
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13
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Leydig cell aging: Molecular mechanisms and treatments. VITAMINS AND HORMONES 2021; 115:585-609. [PMID: 33706963 DOI: 10.1016/bs.vh.2020.12.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Late-onset hypogonadism, resulting from deficiency in serum testosterone (T), affects the health and quality of life of millions of aging men. T is synthesized by Leydig cells (LCs) in response to luteinizing hormone (LH). LH binds LC plasma membrane receptors, inducing the formation of a supramolecular complex of cytosolic and mitochondrial proteins, the Steroidogenic InteracTomE (SITE). SITE proteins are involved in targeting cholesterol to CYP11A1 in the mitochondria, the first enzyme of the steroidogenic cascade. Cholesterol translocation is the rate-determining step in T formation. With aging, LC defects occur that include changes in SITE, an increasingly oxidative intracellular environment, and reduced androgen formation and serum T levels. T replacement therapy (TRT) will restore T levels, but reported side effects make it desirable to develop additional strategies for increasing T. One approach is to target LC protein-protein interactions and thus increase T production by the hypofunctional Leydig cells themselves.
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Ge RS, Li X, Wang Y. Leydig Cell and Spermatogenesis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1288:111-129. [PMID: 34453734 DOI: 10.1007/978-3-030-77779-1_6] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Leydig cells of the testis have the capacity to synthesize androgen (mainly testosterone) from cholesterol. Adult Leydig cells are the cell type for the synthesis of testosterone, which is critical for spermatogenesis. At least four steroidogenic enzymes take part in testosterone synthesis: cytochrome P450 cholesterol side chain cleavage enzyme, 3β-hydroxysteroid dehydrogenase, cytochrome P450 17α-hydroxylase/17,20-lyase and 17β-hydroxysteroid dehydrogenase isoform 3. Testosterone metabolic enzyme steroid 5α-reductase 1 and 3α-hydroxysteroid dehydrogenase are expressed in some precursor Leydig cells. Androgen is transported by androgen-binding protein to Sertoli cells, where it binds to androgen receptor to regulate spermatogenesis.
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Affiliation(s)
- Ren-Shan Ge
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China.
| | - Xiaoheng Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
| | - Yiyan Wang
- The Second Affiliated Hospital and Yuying Children's Hospital, Wenzhou Medical University, Wenzhou, China
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15
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Fan J, Papadopoulos V. Mitochondrial TSPO Deficiency Triggers Retrograde Signaling in MA-10 Mouse Tumor Leydig Cells. Int J Mol Sci 2020; 22:ijms22010252. [PMID: 33383772 PMCID: PMC7795497 DOI: 10.3390/ijms22010252] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 12/10/2020] [Accepted: 12/22/2020] [Indexed: 12/13/2022] Open
Abstract
The mitochondrial translocator protein (TSPO) has been shown to bind cholesterol with high affinity and is involved in mediating its availability for steroidogenesis. We recently reported that targeted Tspo gene deletion in MA-10 mouse tumor Leydig cells resulted in reduced cAMP-stimulated steroid formation and significant reduction in the mitochondrial membrane potential (ΔΨm) compared to control cells. We hypothesized that ΔΨm reduction in the absence of TSPO probably reflects the dysregulation and/or maintenance failure of some basic mitochondrial function(s). To explore the consequences of TSPO depletion via CRISPR-Cas9-mediated deletion (indel) mutation in MA-10 cells, we assessed the transcriptome changes in TSPO-mutant versus wild-type (Wt) cells using RNA-seq. Gene expression profiles were validated using real-time PCR. We report herein that there are significant changes in nuclear gene expression in Tspo mutant versus Wt cells. The identified transcriptome changes were mapped to several signaling pathways including the regulation of membrane potential, calcium signaling, extracellular matrix, and phagocytosis. This is a retrograde signaling pathway from the mitochondria to the nucleus and is probably the result of changes in expression of several transcription factors, including key members of the NF-κB pathway. In conclusion, TSPO regulates nuclear gene expression through intracellular signaling. This is the first evidence of a compensatory response to the loss of TSPO with transcriptome changes at the cellular level.
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Affiliation(s)
- Jinjiang Fan
- The Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada;
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
| | - Vassilios Papadopoulos
- The Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada;
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089, USA
- Correspondence: ; Fax: +1-323-442-1681
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Fan J, Martinez-Arguelles DB, Papadopoulos V. Genome-wide expression analysis of a new class of lncRNAs driven by SINE B2. Gene 2020; 768:145332. [PMID: 33278552 DOI: 10.1016/j.gene.2020.145332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 09/13/2020] [Accepted: 11/27/2020] [Indexed: 12/30/2022]
Abstract
Repetitive short interspersed elements B2 (SINE B2) have been shown to possess two promoters: polymerase III promoter for producing short B2-S RNAs and polymerase II promoter for driving the expression of long non-coding RNA (B2-AS lncRNAs). Using a B2-antisense (B2-AS) transcript sequence from the SINE B2 resident in mitochondrial translocator protein gene (Tspo) locus, we constructed a B2-AS specific RNA library and identified 96,862 sequences encoding potential B2-mediated lncRNAs, of which 55,592 lncRNAs with more than 390 nt in length possess a feature of potential genomic locus-specific effect. In addition, small RNA-Northern hybridization showed that the new B2-AS lncRNAs are constantly degraded by the Dicer1 enzyme, a finding further confirmed by in vitro Dicer1 enzyme digestion. B2-AS lncRNAs regulate the expression of target genes in a different fashion than B2-S RNAs. Genome-wide cross-comparison with mRNA mapping showed a total of 904 mRNA loci directly targeted by B2-AS lncRNAs, suggesting a locus-specific effect of the B2-AS lncRNAs and a general effect of B2-S RNAs.
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Affiliation(s)
- Jinjiang Fan
- The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada
| | | | - Vassilios Papadopoulos
- The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada; Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States.
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17
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A systematic review of post-translational modifications in the mitochondrial permeability transition pore complex associated with cardiac diseases. Biochim Biophys Acta Mol Basis Dis 2020; 1867:165992. [PMID: 33091565 DOI: 10.1016/j.bbadis.2020.165992] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/23/2020] [Accepted: 10/08/2020] [Indexed: 12/28/2022]
Abstract
The mitochondrial permeability transition pore (mPTP) opening is involved in the pathophysiology of multiple cardiac diseases, such as ischemia/reperfusion injury and heart failure. A growing number of evidence provided by proteomic screening techniques has demonstrated the role of post-translational modifications (PTMs) in several key components of the pore in response to changes in the extra/intracellular environment and bioenergetic demand. This could lead to a fine, complex regulatory mechanism that, under pathological conditions, can shift the state of mitochondrial functions and, thus, the cell's fate. Understanding the complex relationship between these PTMs is still under investigation and can provide new, promising therapeutic targets and treatment approaches. This review, using a systematic review of the literature, presents the current knowledge on PTMs of the mPTP and their role in health and cardiac disease.
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18
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Ammer LM, Vollmann-Zwerenz A, Ruf V, Wetzel CH, Riemenschneider MJ, Albert NL, Beckhove P, Hau P. The Role of Translocator Protein TSPO in Hallmarks of Glioblastoma. Cancers (Basel) 2020; 12:cancers12102973. [PMID: 33066460 PMCID: PMC7602186 DOI: 10.3390/cancers12102973] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/09/2020] [Accepted: 10/09/2020] [Indexed: 12/18/2022] Open
Abstract
Simple Summary The translocator protein (TSPO) has been under extensive investigation as a specific marker in positron emission tomography (PET) to visualize brain lesions following injury or disease. In recent years, TSPO is increasingly appreciated as a potential novel therapeutic target in cancer. In Glioblastoma (GBM), the most malignant primary brain tumor, TSPO expression levels are strongly elevated and scientific evidence accumulates, hinting at a pivotal role of TSPO in tumorigenesis and glioma progression. The aim of this review is to summarize the current literature on TSPO with respect to its role both in diagnostics and especially with regard to the critical hallmarks of cancer postulated by Hanahan and Weinberg. Overall, our review contributes to a better understanding of the functional significance of TSPO in Glioblastoma and draws attention to TSPO as a potential modulator of treatment response and thus an important factor that may influence the clinical outcome of GBM. Abstract Glioblastoma (GBM) is the most fatal primary brain cancer in adults. Despite extensive treatment, tumors inevitably recur, leading to an average survival time shorter than 1.5 years. The 18 kDa translocator protein (TSPO) is abundantly expressed throughout the body including the central nervous system. The expression of TSPO increases in states of inflammation and brain injury due to microglia activation. Not least due to its location in the outer mitochondrial membrane, TSPO has been implicated with a broad spectrum of functions. These include the regulation of proliferation, apoptosis, migration, as well as mitochondrial functions such as mitochondrial respiration and oxidative stress regulation. TSPO is frequently overexpressed in GBM. Its expression level has been positively correlated to WHO grade, glioma cell proliferation, and poor prognosis of patients. Several lines of evidence indicate that TSPO plays a functional part in glioma hallmark features such as resistance to apoptosis, invasiveness, and proliferation. This review provides a critical overview of how TSPO could regulate several aspects of tumorigenesis in GBM, particularly in the context of the hallmarks of cancer proposed by Hanahan and Weinberg in 2011.
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Affiliation(s)
- Laura-Marie Ammer
- Wilhelm Sander-NeuroOncology Unit and Department of Neurology, University Hospital Regensburg, 93053 Regensburg, Germany; (L.-M.A.); (A.V.-Z.)
| | - Arabel Vollmann-Zwerenz
- Wilhelm Sander-NeuroOncology Unit and Department of Neurology, University Hospital Regensburg, 93053 Regensburg, Germany; (L.-M.A.); (A.V.-Z.)
| | - Viktoria Ruf
- Center for Neuropathology and Prion Research, Ludwig Maximilians University of Munich, 81377 Munich, Germany;
| | - Christian H. Wetzel
- Molecular Neurosciences, Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany;
| | | | - Nathalie L. Albert
- Department of Nuclear Medicine, Ludwig-Maximilians-University Munich, 81377 Munich, Germany;
| | - Philipp Beckhove
- Regensburg Center for Interventional Immunology (RCI) and Department Internal Medicine III, University Hospital Regensburg, 93053 Regensburg, Germany;
| | - Peter Hau
- Wilhelm Sander-NeuroOncology Unit and Department of Neurology, University Hospital Regensburg, 93053 Regensburg, Germany; (L.-M.A.); (A.V.-Z.)
- Correspondence:
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19
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Musicki B, Karakus S, La Favor JD, Chen H, Silva FH, Sturny M, Zirkin BR, Burnett AL. TSPO ligand FGIN-1-27 controls priapism in sickle cell mice via endogenous testosterone production. J Cell Physiol 2020; 236:3073-3082. [PMID: 32974910 DOI: 10.1002/jcp.30075] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 11/10/2022]
Abstract
Priapism, a prolonged penile erection in the absence of sexual arousal, is common among patients with sickle cell disease (SCD). Hypogonadism is also common in patients with SCD. While the administration of exogenous testosterone reverses hypogonadism, it is contraceptive. We hypothesized that the stimulation of endogenous testosterone production decreases priapism by normalizing molecular signaling involved in penile erection without decreasing intratesticular testosterone production, which would affect fertility. Treatment of SCD mice with FGIN-1-27, a ligand for translocator protein (TSPO) that mobilizes cholesterol to the inner mitochondrial membrane, resulted in eugonadal levels of serum testosterone without decreasing intratesticular testosterone production. Normalized testosterone levels, in turn, decreased priapism. At the molecular level, TSPO restored phosphodiesterase 5 activity and decreased NADPH oxidase-mediated oxidative stress in the penis, which are major molecular signaling molecules involved in penile erection and are dysregulated in SCD. These results indicate that pharmacologic activation of TSPO could be a novel, targetable pathway for treating hypogonadal men, particularly patients with SCD, without adverse effects on fertility.
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Affiliation(s)
- Biljana Musicki
- Department of Urology, The James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Serkan Karakus
- Department of Urology, The James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Justin D La Favor
- Department of Urology, The James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.,Department of Nutrition, Food and Exercise Sciences, Florida State University, Tallahassee, Florida, USA
| | - Haolin Chen
- Department of Biochemistry and Molecular Biology, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Fabio H Silva
- Department of Urology, The James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Mikael Sturny
- Department of Urology, The James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Barry R Zirkin
- Department of Biochemistry and Molecular Biology, The Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Arthur L Burnett
- Department of Urology, The James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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20
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Rao R, Diharce J, Dugué B, Ostuni MA, Cadet F, Etchebest C. Versatile Dimerisation Process of Translocator Protein (TSPO) Revealed by an Extensive Sampling Based on a Coarse-Grained Dynamics Study. J Chem Inf Model 2020; 60:3944-3957. [DOI: 10.1021/acs.jcim.0c00246] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Rajas Rao
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
| | - Julien Diharce
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
| | - Bérénice Dugué
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
| | - Mariano A. Ostuni
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
| | - Frédéric Cadet
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
- PEACCEL, Artificial Intelligence Department, 6 Square Albin Cachot, Box 42, 75013 Paris, France
| | - Catherine Etchebest
- Université de Paris, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, INSERM, F-75015, Paris, France
- Laboratoire d’Excellence GR-Ex, 75015 Paris, France
- Université de la Réunion, Biologie Intégrée du Globule Rouge, UMR_S1134, BIGR, Faculté des Sciences & Technologies Saint-Denis, F-97715 St. Denis, France
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21
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Chen F, Lu H, Chen P, Zhao X, Guan X, Liang Q, Zirkin BR, Ye L, Chen H. Acute effects of the translocator protein drug ligand FGIN-1-27 on serum testosterone and luteinizing hormone levels in male Sprague-Dawley rats†. Biol Reprod 2020; 100:824-832. [PMID: 30299464 DOI: 10.1093/biolre/ioy220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 08/24/2018] [Accepted: 10/05/2018] [Indexed: 12/12/2022] Open
Abstract
We reported that FGIN-1-27 (N,N-dihexyl-2-(4-fluorophenyl)indole-3-acetamide, FGIN), a synthetic ligand for translocator protein (TSPO, 18 kDa), increased serum testosterone levels in young and aged Brown Norway rats after its administration daily for 10 days. It is not known, however, how soon after treatment with FGIN serum testosterone rises, how long levels remain elevated after cessation of treatment, or whether the drug acts solely through TSPO. Adult Sprague-Dawley male rats received a single ip dose of FGIN (1 mg/kg BW). Serial blood samples were collected, and serum testosterone and luteinizing hormone (LH) were assessed hourly throughout 24 h. Testosterone concentration was maximal by 3 h, remained significantly higher than the controls at 10 h, and returned to the control level by 24 h. Consistent with the in vivo study, culturing isolated Leydig cells with either FGIN (40 μM) or LH (0.1 ng/ml) resulted in significantly increased testosterone production by 30 min, and the stimulatory effects persisted through 48 h. At a very early (15 min) treatment time, however, FGIN significantly increased testosterone production but LH had not yet done so. Surprisingly, in vivo treatment with FGIN not only increased serum testosterone but also serum LH concentration, raising the possibility that FGIN may increase serum testosterone concentration by dual mechanisms.
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Affiliation(s)
- Fenfen Chen
- Department of Gynaecology and Obstetrics, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.,Department of Anesthesiology, Perioperative Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Hemin Lu
- Department of Pediatrics, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Panpan Chen
- Department of Gynaecology and Obstetrics, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Xingxing Zhao
- Department of Anesthesiology, Perioperative Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.,Zhejiang Province Key Lab of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Xiaojui Guan
- Department of Anesthesiology, Perioperative Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.,Zhejiang Province Key Lab of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Qingquan Liang
- Department of Anesthesiology, Perioperative Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.,Zhejiang Province Key Lab of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Barry R Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Leping Ye
- Department of Pediatrics, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China
| | - Haolin Chen
- Department of Gynaecology and Obstetrics, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.,Department of Anesthesiology, Perioperative Medicine, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.,Zhejiang Province Key Lab of Anesthesiology, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325027, China.,Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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Tonon MC, Vaudry H, Chuquet J, Guillebaud F, Fan J, Masmoudi-Kouki O, Vaudry D, Lanfray D, Morin F, Prevot V, Papadopoulos V, Troadec JD, Leprince J. Endozepines and their receptors: Structure, functions and pathophysiological significance. Pharmacol Ther 2020; 208:107386. [DOI: 10.1016/j.pharmthera.2019.06.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/20/2019] [Indexed: 02/06/2023]
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23
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Shin JH, Lee G, Jeong MG, Kim HK, Won HY, Choi Y, Lee JH, Nam M, Choi CS, Hwang GS, Hwang ES. Transcriptional coactivator with PDZ-binding motif suppresses the expression of steroidogenic enzymes by nuclear receptor 4 A1 in Leydig cells. FASEB J 2020; 34:5332-5347. [PMID: 32067268 DOI: 10.1096/fj.201900695rrrr] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 01/20/2023]
Abstract
Transcriptional coactivator with PDZ-binding motif (TAZ) plays crucial role in maintaining testicular structure and function via regulation of senescence of spermatogenic cells. However, it remains unclear whether TAZ is involved in testosterone biosynthesis in testicular Leydig cells. We found that TAZ deficiency caused aberrant Leydig cell expansion and increased lipid droplet formation, which was significantly associated with increased lipogenic enzyme expression. Additionally, the expression of key steroidogenic enzymes, including steroidogenic acute regulatory protein, cytochrome P450 (CYP) 11A1, CYP17A1, and 3β-hydroxysteroid dehydrogenase, was greatly increased in TAZ-deficient testes and primary Leydig cells. Interestingly, the transcriptional activity of nuclear receptor 4 A1 (NR4A1) was dramatically suppressed by TAZ; however, the protein expression and the subcellular localization of NR4A1 were not affected by TAZ. TAZ directly associated with the N-terminal region of NR4A1 and substantially suppressed its DNA-binding and transcriptional activities. Stable expression of TAZ in the mouse Leydig TM3 cell line decreased the expression of key steroidogenic enzymes, whereas knockdown of endogenous TAZ in TM3 cells increased transcripts of steroidogenic genes induced by NR4A1. Consistently, testosterone production was enhanced within TAZ-deficient Leydig cells. However, TAZ deficiency resulted in decreased testosterone secretion caused by dysfunctional mitochondria and lysosomes. Therefore, TAZ plays essential role in NR4A1-induced steroidogenic enzyme expression and testosterone production in Leydig cells.
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Affiliation(s)
- Ji Hyun Shin
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Gibbeum Lee
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Mi Gyeong Jeong
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Hyo Kyeong Kim
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Hee Yeon Won
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Yujeong Choi
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Korea
| | - Ji-Hyeok Lee
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University School of Medicine, Incheon, Korea
| | - Miso Nam
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea
| | - Cheol Soo Choi
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University School of Medicine, Incheon, Korea
| | - Geum-Sook Hwang
- Integrated Metabolomics Research Group, Western Seoul Center, Korea Basic Science Institute, Seoul, Korea
| | - Eun Sook Hwang
- Graduate School of Pharmaceutical Sciences, College of Pharmacy, Ewha Womans University, Seoul, Korea
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Fan J, Campioli E, Sottas C, Zirkin B, Papadopoulos V. Amhr2-Cre-Mediated Global Tspo Knockout. J Endocr Soc 2020; 4:bvaa001. [PMID: 32099945 PMCID: PMC7031085 DOI: 10.1210/jendso/bvaa001] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 01/09/2020] [Indexed: 12/27/2022] Open
Abstract
Although the role of translocator protein (TSPO) in cholesterol transport in steroid-synthesizing cells has been studied extensively, recent studies of TSPO genetic depletion have questioned its role. Amhr2-Cre mice have been used to generate Leydig cell-specific Tspo conditional knockout (cKO) mice. Using the same Cre line, we were unable to generate Tspo cKO mice possibly because of genetic linkage between Tspo and Amhr2 and coexpression of Amhr2-Cre and Tspo in early embryonic development. We found that Amhr2-Cre is expressed during preimplantation stages, resulting in global heterozygous mice (gHE; Amhr2-Cre+/–,Tspo–/+). Two gHE mice were crossed, generating Amhr2-Cre–mediated Tspo global knockout (gKO; Tspo–/–) mice. We found that 33.3% of blastocysts at E3.5 to E4.5 showed normal morphology, whereas 66.7% showed delayed development, which correlates with the expected Mendelian proportions of Tspo+/+ (25%), Tspo–/– (25%), and Tspo+/– (50%) genotypes from crossing 2 Tspo–/+ mice. Adult Tspo gKO mice exhibited disturbances in neutral lipid homeostasis and reduced intratesticular and circulating testosterone levels, but no change in circulating basal corticosterone levels. RNA-sequencing data from mouse adrenal glands and lungs revealed transcriptome changes in response to the loss of TSPO, including changes in several cholesterol-binding and transfer proteins. This study demonstrates that Amhr2-Cre can be used to produce Tspo gKO mice instead of cKO, and can serve as a new global “Cre deleter.” Moreover, our results show that Tspo deletion causes delayed preimplantation embryonic development, alters neutral lipid storage and steroidogenesis, and leads to transcriptome changes that may reflect compensatory mechanisms in response to the loss of function of TSPO.
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Affiliation(s)
- Jinjiang Fan
- The Research Institute of the McGill University Health Centre.,Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Enrico Campioli
- The Research Institute of the McGill University Health Centre.,Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Chantal Sottas
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, US
| | - Barry Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, US
| | - Vassilios Papadopoulos
- The Research Institute of the McGill University Health Centre.,Department of Medicine, McGill University, Montreal, Quebec, Canada.,Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, US
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25
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Selvaraj V, Morohaku K, Koganti PP, Zhang J, He W, Quirk SM, Stocco DM. Commentary: Amhr2-Cre-Mediated Global Tspo Knockout. Front Endocrinol (Lausanne) 2020; 11:472. [PMID: 32793121 PMCID: PMC7393387 DOI: 10.3389/fendo.2020.00472] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/16/2020] [Indexed: 11/26/2022] Open
Affiliation(s)
- Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
- *Correspondence: Vimal Selvaraj
| | - Kanako Morohaku
- Division of Animal Science, School of Science and Technology, Institute of Agriculture, Shinshu University, Nagano, Japan
| | - Prasanthi P. Koganti
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Jianmin Zhang
- State Key Laboratory of Medical Molecular Biology, Department of Immunology, Research Center on Pediatric Development Diseases, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Wei He
- State Key Laboratory of Medical Molecular Biology, Department of Immunology, Research Center on Pediatric Development Diseases, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Susan M. Quirk
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY, United States
| | - Douglas M. Stocco
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX, United States
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26
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Chung JY, Chen H, Papadopoulos V, Zirkin B. Cholesterol accumulation, lipid droplet formation, and steroid production in Leydig cells: Role of translocator protein (18-kDa). Andrology 2019; 8:719-730. [PMID: 31738001 DOI: 10.1111/andr.12733] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2019] [Revised: 11/06/2019] [Accepted: 11/14/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND Cholesterol import into the mitochondria of steroid-producing cells is the rate-determining step in steroidogenesis. Numerous studies have provided evidence that the cholesterol-binding translocator protein (18 kDa TSPO) plays an important role in cholesterol translocation into mitochondria and that it also might act on cholesterol homeostasis. Several TSPO-specific ligands have been shown to increase steroid production in vitro and in vivo. OBJECTIVES The present study assessed the effects of the TSPO drug ligand FGIN-1-27 on cholesterol accumulation and lipid droplet formation in relationship to steroid formation. MATERIALS AND METHODS Using MA-10 and primary Leydig cells, immunocytochemical and molecular methods were used to examine cholesterol accumulation, the formation of lipid droplets, and steroid formation in response to LH and FGIN-1-27. Additionally, we determined the effects of Tspo knockout by CRISPR/Cas9, and of siRNA knockdowns of Tspo and Plin2 (Perilipin 2; also known as adipose differentiation-related protein, ADFP) on LH- and FGIN-1-27-induced steroidogenesis. RESULTS In response to LH and FGIN-1-27, cultured MA-10 cells and primary Leydig cells increased steroid formation, cholesterol accumulation, and lipid droplet formation. Cholesterol accumulation in the lipid droplets also was increased in Tspo knockout cells. Knockout of Tspo or its knockdown in MA-10 cells resulted in reduced progesterone formation in response to both LH and FGIN-1-27, as did knockdown of Plin2. Steroid production also was inhibited by the cholesteryl ester hydrolase inhibitor diethylumbelliferyl phosphate. DISCUSSION AND CONCLUSION These results support the conclusion that FGIN-1-27 stimulates steroid formation by increasing TSPO-mediated cholesterol translocation into the inner mitochondria for steroidogenesis, as well as into the cytosol for lipid droplet formation. FGIN-1-27 also increased steroid formation at least in part by inducing the conversion of cholesteryl ester located in lipid droplets to cholesterol, thus making available more substrate for steroid formation.
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Affiliation(s)
- Jin-Yong Chung
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Haolin Chen
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Department of Anesthesiology, the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Science, School of Pharmacy, University of Southern California, Los Angeles, CA, USA
| | - Barry Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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27
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Cao S, Sun Y, Wang W, Wang B, Zhang Q, Pan C, Yuan Q, Xu F, Wei S, Chen Y. Poly (ADP-ribose) polymerase inhibition protects against myocardial ischaemia/reperfusion injury via suppressing mitophagy. J Cell Mol Med 2019; 23:6897-6906. [PMID: 31379115 PMCID: PMC6787458 DOI: 10.1111/jcmm.14573] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Revised: 06/20/2019] [Accepted: 07/08/2019] [Indexed: 12/11/2022] Open
Abstract
Myocardial ischaemia/reperfusion (I/R) injury attenuates the beneficial effects of reperfusion therapy. Poly(ADP-ribose) polymerase (PARP) is overactivated during myocardial I/R injury. Mitophagy plays a critical role in the development of myocardial I/R injury. However, the effect of PARP activation on mitophagy in cardiomyocytes is unknown. In this study, we found that I/R induced PARP activation and mitophagy in mouse hearts. Poly(ADP-ribose) polymerase inhibition reduced the infarct size and suppressed mitophagy after myocardial I/R injury. In vitro, hypoxia/reoxygenation (H/R) activated PARP, promoted mitophagy and induced cell apoptosis in cardiomyocytes. Poly(ADP-ribose) polymerase inhibition suppressed H/R-induced mitophagy and cell apoptosis. Parkin knockdown with lentivirus vectors inhibited mitophagy and prevented cell apoptosis in H/R-treated cells. Poly(ADP-ribose) polymerase inhibition prevented the loss of the mitochondrial membrane potential (ΔΨm). Cyclosporin A maintained ΔΨm and suppressed mitophagy but FCCP reduced the effect of PARP inhibition on ΔΨm and promoted mitophagy, indicating the critical role of ΔΨm in H/R-induced mitophagy. Furthermore, reactive oxygen species (ROS) and poly(ADP-ribosylation) of CypD and TSPO might contribute to the regulation of ΔΨm by PARP. Our findings thus suggest that PARP inhibition protects against I/R-induced cell apoptosis by suppressing excessive mitophagy via the ΔΨm/Parkin pathway.
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Affiliation(s)
- Shengchuan Cao
- Department of Emergency and Chest Pain CenterQilu Hospital of Shandong UniversityJinanChina
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Institute of Emergency and Critical Care Medicine of Shandong UniversityQilu Hospital of Shandong UniversityJinanChina
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary‐Cerebral Resuscitation Research of Shandong ProvinceQilu Hospital of Shandong UniversityJinanChina
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineQilu Hospital of Shandong UniversityJinanChina
| | - Yiying Sun
- Department of Emergency and Chest Pain CenterQilu Hospital of Shandong UniversityJinanChina
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Institute of Emergency and Critical Care Medicine of Shandong UniversityQilu Hospital of Shandong UniversityJinanChina
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary‐Cerebral Resuscitation Research of Shandong ProvinceQilu Hospital of Shandong UniversityJinanChina
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineQilu Hospital of Shandong UniversityJinanChina
| | - Wenjun Wang
- Department of Emergency and Chest Pain CenterQilu Hospital of Shandong UniversityJinanChina
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Institute of Emergency and Critical Care Medicine of Shandong UniversityQilu Hospital of Shandong UniversityJinanChina
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary‐Cerebral Resuscitation Research of Shandong ProvinceQilu Hospital of Shandong UniversityJinanChina
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineQilu Hospital of Shandong UniversityJinanChina
| | - Bailu Wang
- Clinical Trial CenterQilu Hospital of Shandong UniversityJinanChina
| | - Qun Zhang
- Department of Emergency and Chest Pain CenterQilu Hospital of Shandong UniversityJinanChina
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Institute of Emergency and Critical Care Medicine of Shandong UniversityQilu Hospital of Shandong UniversityJinanChina
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary‐Cerebral Resuscitation Research of Shandong ProvinceQilu Hospital of Shandong UniversityJinanChina
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineQilu Hospital of Shandong UniversityJinanChina
| | - Chang Pan
- Department of Emergency and Chest Pain CenterQilu Hospital of Shandong UniversityJinanChina
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Institute of Emergency and Critical Care Medicine of Shandong UniversityQilu Hospital of Shandong UniversityJinanChina
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary‐Cerebral Resuscitation Research of Shandong ProvinceQilu Hospital of Shandong UniversityJinanChina
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineQilu Hospital of Shandong UniversityJinanChina
| | - Qiuhuan Yuan
- Department of Emergency and Chest Pain CenterQilu Hospital of Shandong UniversityJinanChina
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Institute of Emergency and Critical Care Medicine of Shandong UniversityQilu Hospital of Shandong UniversityJinanChina
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary‐Cerebral Resuscitation Research of Shandong ProvinceQilu Hospital of Shandong UniversityJinanChina
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineQilu Hospital of Shandong UniversityJinanChina
| | - Feng Xu
- Department of Emergency and Chest Pain CenterQilu Hospital of Shandong UniversityJinanChina
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Institute of Emergency and Critical Care Medicine of Shandong UniversityQilu Hospital of Shandong UniversityJinanChina
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary‐Cerebral Resuscitation Research of Shandong ProvinceQilu Hospital of Shandong UniversityJinanChina
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineQilu Hospital of Shandong UniversityJinanChina
| | - Shujian Wei
- Department of Emergency and Chest Pain CenterQilu Hospital of Shandong UniversityJinanChina
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Institute of Emergency and Critical Care Medicine of Shandong UniversityQilu Hospital of Shandong UniversityJinanChina
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary‐Cerebral Resuscitation Research of Shandong ProvinceQilu Hospital of Shandong UniversityJinanChina
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineQilu Hospital of Shandong UniversityJinanChina
| | - Yuguo Chen
- Department of Emergency and Chest Pain CenterQilu Hospital of Shandong UniversityJinanChina
- Clinical Research Center for Emergency and Critical Care Medicine of Shandong Province, Institute of Emergency and Critical Care Medicine of Shandong UniversityQilu Hospital of Shandong UniversityJinanChina
- Key Laboratory of Emergency and Critical Care Medicine of Shandong Province, Key Laboratory of Cardiopulmonary‐Cerebral Resuscitation Research of Shandong ProvinceQilu Hospital of Shandong UniversityJinanChina
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education, Chinese Ministry of Health and Chinese Academy of Medical Sciences, The State and Shandong Province Joint Key Laboratory of Translational Cardiovascular MedicineQilu Hospital of Shandong UniversityJinanChina
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Arbo B, Ribeiro M, Garcia-Segura L. Development of new treatments for Alzheimer's disease based on the modulation of translocator protein (TSPO). Ageing Res Rev 2019; 54:100943. [PMID: 31430564 DOI: 10.1016/j.arr.2019.100943] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 08/07/2019] [Accepted: 08/15/2019] [Indexed: 12/27/2022]
Abstract
The increase in life expectancy of the world population is associated with a higher prevalence of neurodegenerative diseases. Alzheimer's Disease (AD) is the most common neurodegenerative disease, affecting currently 43 million people over the world. To date, most of the pharmacological interventions in AD are intended for the alleviation of some of its symptoms, and there are no effective treatments to inhibit the progression of the disease. Translocator protein (TSPO) is present in contact points between the outer and the inner mitochondrial membranes and is involved in the control of steroidogenesis, inflammation and apoptosis. In the last decade, studies have shown that TSPO ligands present neuroprotective effects in different experimental models of AD, both in vitro and in vivo. The aim of this review is to analyze the data provided by these studies and to discuss if TSPO could be a viable therapeutic target for the development of new treatments for AD.
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29
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Zirkin BR, Papadopoulos V. Leydig cells: formation, function, and regulation. Biol Reprod 2019; 99:101-111. [PMID: 29566165 DOI: 10.1093/biolre/ioy059] [Citation(s) in RCA: 324] [Impact Index Per Article: 64.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 03/11/2018] [Indexed: 12/23/2022] Open
Abstract
Herein we summarize important discoveries made over many years about Leydig cell function and regulation. Fetal Leydig cells produce the high levels of androgen (testosterone or androstenedione, depending upon the species) required for differentiation of male genitalia and brain masculinization. Androgen production declines with loss of these cells, reaching a nadir at postpartum. Testosterone then gradually increases to high levels with adult Leydig cell development from stem cells. In the adult, luteinizing hormone (LH) binding to Leydig cell LH receptors stimulates cAMP production, increasing the rate of cholesterol translocation into the mitochondria. Cholesterol is metabolized to pregnenolone by the CYP11A1 enzyme at the inner mitochondrial membrane, and pregnenolone to testosterone by mitochondria and smooth endoplasmic reticulum enzymes. Cholesterol translocation to the inner mitochondrial membrane is mediated by a protein complex formed at mitochondrial contact sites that consists of the cholesterol binding translocator protein, voltage dependent anion channel, and other mitochondrial and cytosolic proteins. Steroidogenic acute regulatory protein acts at this complex to enhance cholesterol movement across the membranes and thus increase testosterone formation. The 14-3-3γ and ε adaptor proteins serve as negative regulators of steroidogenesis, controlling the maximal amount of steroid formed. Decline in testosterone production occurs in many aging and young men, resulting in metabolic and quality-of-life changes. Testosterone replacement therapy is widely used to elevate serum testosterone levels in hypogonadal men. With knowledge gained of the mechanisms involved in testosterone formation, it is also conceivable to use pharmacological means to increase serum testosterone by Leydig cell stimulation.
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Affiliation(s)
- Barry R Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California, USA
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30
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Milenkovic VM, Slim D, Bader S, Koch V, Heinl ES, Alvarez-Carbonell D, Nothdurfter C, Rupprecht R, Wetzel CH. CRISPR-Cas9 Mediated TSPO Gene Knockout alters Respiration and Cellular Metabolism in Human Primary Microglia Cells. Int J Mol Sci 2019; 20:ijms20133359. [PMID: 31323920 PMCID: PMC6651328 DOI: 10.3390/ijms20133359] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/04/2019] [Accepted: 07/07/2019] [Indexed: 02/06/2023] Open
Abstract
The 18 kDa translocator protein (TSPO) is an evolutionary conserved cholesterol binding protein localized in the outer mitochondrial membrane. It has been implicated in the regulation of various cellular processes including oxidative stress, proliferation, apoptosis, and steroid hormone biosynthesis. Since the expression of TSPO in activated microglia is upregulated in various neuroinflammatory and neurodegenerative disorders, we set out to examine the role of TSPO in an immortalized human microglia C20 cell line. To this end, we performed a dual approach and used (i) lentiviral shRNA silencing to reduce TSPO expression, and (ii) the CRISPR/Cas9 technology to generate complete TSPO knockout microglia cell lines. Functional characterization of control and TSPO knockdown as well as knockout cells, revealed only low de novo steroidogenesis in C20 cells, which was not dependent on the level of TSPO expression or influenced by the treatment with TSPO-specific ligands. In contrast to TSPO knockdown C20 cells, which did not show altered mitochondrial function, the TSPO deficient knockout cells displayed a significantly decreased mitochondrial membrane potential and cytosolic Ca2+ levels, as well as reduced respiratory function. Performing the rescue experiment by lentiviral overexpression of TSPO in knockout cells, increased oxygen consumption and restored respiratory function. Our study provides further evidence for a significant role of TSPO in cellular and mitochondrial metabolism and demonstrates that different phenotypes of mitochondrial function are dependent on the level of TSPO expression.
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Affiliation(s)
- Vladimir M Milenkovic
- Molecular Neurosciences, Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Dounia Slim
- Molecular Neurosciences, Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Stefanie Bader
- Molecular Neurosciences, Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Victoria Koch
- Molecular Neurosciences, Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Elena-Sofia Heinl
- Molecular Neurosciences, Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - David Alvarez-Carbonell
- Department of Molecular Biology and Microbiology, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Caroline Nothdurfter
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Rainer Rupprecht
- Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany
| | - Christian H Wetzel
- Molecular Neurosciences, Department of Psychiatry and Psychotherapy, University of Regensburg, 93053 Regensburg, Germany.
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Regulation of Leydig cell steroidogenesis: intriguing network of signaling pathways and mitochondrial signalosome. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.coemr.2019.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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32
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Manna PR, Ahmed AU, Yang S, Narasimhan M, Cohen-Tannoudji J, Slominski AT, Pruitt K. Genomic Profiling of the Steroidogenic Acute Regulatory Protein in Breast Cancer: In Silico Assessments and a Mechanistic Perspective. Cancers (Basel) 2019; 11:cancers11050623. [PMID: 31060224 PMCID: PMC6562549 DOI: 10.3390/cancers11050623] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 04/27/2019] [Accepted: 04/30/2019] [Indexed: 12/30/2022] Open
Abstract
Cancer is a multifactorial condition with aberrant growth of cells. A substantial number of cancers, breast in particular, are hormone sensitive and evolve due to malfunction in the steroidogenic machinery. Breast cancer, one of the most prevalent form of cancers in women, is primarily stimulated by estrogens. Steroid hormones are made from cholesterol, and regulation of steroid/estrogen biosynthesis is essentially influenced by the steroidogenic acute regulatory (StAR) protein. Although the impact of StAR in breast cancer remains a mystery, we recently reported that StAR protein is abundantly expressed in hormone sensitive breast cancer, but not in its non-cancerous counterpart. Herein, we analyzed genomic profiles, hormone receptor expression, mutation, and survival for StAR and steroidogenic enzyme genes in a variety of hormone sensitive cancers. These profiles were specifically assessed in breast cancer, exploiting The Cancer Genome Atlas (TCGA) datasets. Whereas StAR and key steroidogenic enzyme genes evaluated (CYP11A1, HSD3B, CYP17A1, CYP19A1, and HSD17B) were altered to varying levels in these hormone responsive cancers, amplification of the StAR gene was correlated with poor overall survival of patients afflicted with breast cancer. Amplification of the StAR gene and its correlation to survival was also verified in a number of breast cancer studies. Additionally, TCGA breast cancer tumors associated with aberrant high expression of StAR mRNA were found to be an unfavorable risk factor for survival of patients with breast cancer. Further analyses of tumors, nodal status, and metastases of breast cancer tumors expressing StAR mRNA displayed cancer deaths in stage specific manners. The majority of these tumors were found to express estrogen and progesterone receptors, signifying a link between StAR and luminal subtype breast cancer. Collectively, analyses of genomic and molecular profiles of key steroidogenic factors provide novel insights that StAR plays an important role in the biologic behavior and/or pathogenesis of hormone sensitive breast cancer.
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Affiliation(s)
- Pulak R Manna
- Departments of Immunology and Molecular Microbiology, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Ahsen U Ahmed
- Departments of Immunology and Molecular Microbiology, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Shengping Yang
- Internal Medicine, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Madhusudhanan Narasimhan
- Pharmacology and Neuroscience, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Joëlle Cohen-Tannoudji
- Physiologie de l'axe gonadotrope U1133, Institut National de la Santé et de la Recherche Médicale, CNRS, Biologie Fonctionnelle et Adaptative UMR 8251, Université Paris Diderot, 75205 Paris, France.
| | - Andrzej T Slominski
- Department of Dermatology and Laboratory Medicine, Comprehensive Cancer Center, Cancer Chemoprevention Program, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
- Veterans Administration Medical Center, Birmingham, AL 35294, USA.
| | - Kevin Pruitt
- Departments of Immunology and Molecular Microbiology, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
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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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Fan J, Campioli E, Papadopoulos V. Nr5a1-Cre-mediated Tspo conditional knockout mice with low growth rate and prediabetes symptoms - A mouse model of stress diabetes. Biochim Biophys Acta Mol Basis Dis 2018; 1865:56-62. [PMID: 30343141 DOI: 10.1016/j.bbadis.2018.10.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 10/10/2018] [Accepted: 10/16/2018] [Indexed: 12/16/2022]
Abstract
Translocator protein (TSPO) is a high-affinity cholesterol- and drug-binding mitochondrial protein. Nuclear receptor subfamily 5 group A member 1 or steroidogenic factor 1 (Nr5a1)-Cre mice were previously used to generate steroidogenic cell-specific Tspo gene conditional knockout (cKO) mice. TSPO-depleted homozygotes showed no response to adrenocorticotropic hormone (ACTH) in stimulating adrenal cortex corticosterone production but showed increased epinephrine synthesis in the medulla. No other phenotype was observed under normal growth conditions. During these studies, we noted that pairing two cKO mice resulted in the generation of small pups. These pups showed low growth rate at weaning, which has been linked to the development of type 2 diabetes (T2D) in adulthood. Experimental verification of T2D symptoms via blood testing of the adult mice, including glycated hemoglobin and insulin C-peptide measurements, showed that these Tspo cKO mice exhibited sustained hyperglycemia, a sign of prediabetes, likely due to the augmentation of hepatic glucose production mediated by the increased epinephrine. We also observed increased expression of the S100a8 gene, which is upregulated after chronic glucose stimulation. Taken together, the observed prediabetes phenotype and lack of response to ACTH indicate that Tspo cKO mice (Nr5a1-Cre+/-, Tspofl/fl) could provide a useful model to study the link between diabetes and stress.
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Affiliation(s)
- Jinjiang Fan
- The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Enrico Campioli
- The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Vassilios Papadopoulos
- The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada; Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA, United States.
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Fan J, Zirkin B, Papadopoulos V. Response to Letter to the Editor: "Dubious Conclusions on TSPO Function". Endocrinology 2018; 159:2530-2531. [PMID: 29757373 DOI: 10.1210/en.2018-00292] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 05/03/2018] [Indexed: 11/19/2022]
Affiliation(s)
- Jinjiang Fan
- Research Institute of the McGill University Health Centre and Department of Medicine, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Barry Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Vassilios Papadopoulos
- Research Institute of the McGill University Health Centre and Department of Medicine, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California
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Selvaraj V, Stocco DM. Letter to the Editor: Dubious Conclusions on TSPO Function. Endocrinology 2018; 159:2528-2529. [PMID: 29757419 PMCID: PMC6669408 DOI: 10.1210/en.2018-00052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2018] [Accepted: 03/16/2018] [Indexed: 01/08/2023]
Affiliation(s)
- Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York
- Correspondence: Vimal Selvaraj, PhD, Department of Animal Science, 204 Morrison Hall, Cornell University, Ithaca, New York 14853. E-mail:
| | - Douglas M Stocco
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas
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Translocator protein and steroidogenesis. Biochem J 2018; 475:901-904. [PMID: 29511094 DOI: 10.1042/bcj20170766] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 01/16/2018] [Accepted: 01/18/2018] [Indexed: 02/07/2023]
Abstract
Two interesting papers by Barren et al. and Owen et al. have been very recently published in Biochemical Journal, reporting the role of translocator protein (TSPO) in steroidogenesis. The involvement of TSPO in the steroid biosynthesis has been suggested by 30 years of researches, using biochemical, pharmacological and genetic experimental approaches. In the last 3 years, however, the TSPO involvement in steroidogenesis has been intensively and profoundly discussed. Using in vivo genetic manipulations aimed at deleting TSPO, some researchers have excluded its role in steroid production. Other research groups, using similar genetic manipulation techniques, have presented different results, corroborating the role of TSPO in steroidogenesis, in particular, when hormonal stimulation occurs. In this scenario, the publications by Barron et al. about 'Steroidogenic abnormalities in translocator protein knockout mice and significance in the aging male' and by Owen et al. about 'TSPO mutations in rats and a human polymorphism impair the rate of steroid synthesis' are part of this debate and provide further and more accurate information supporting the importance of TSPO as a steroidogenesis regulator.
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Papadopoulos V, Fan J, Zirkin B. Translocator protein (18 kDa): an update on its function in steroidogenesis. J Neuroendocrinol 2018; 30:10.1111/jne.12500. [PMID: 28667781 PMCID: PMC5748373 DOI: 10.1111/jne.12500] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Revised: 06/26/2017] [Accepted: 06/27/2017] [Indexed: 12/15/2022]
Abstract
Translocator protein (18 kDa) (TSPO) is a ubiquitous mitochondrial protein. Studies of its responses to drug and endogenous ligands have shown TSPO to be involved either directly or indirectly in numerous biological functions, including mitochondrial cholesterol transport and steroid hormone biosynthesis, porphyrin transport and heme synthesis, apoptosis, cell proliferation, and anion transport. Localised to the outer mitochondrial membrane of steroidogenic cells, TSPO has been shown to associate with cytosolic and mitochondrial proteins as part of a large multiprotein complex involved in mitochondrial cholesterol transport, the rate-limiting step in steroidogenesis. There is general agreement as to the structure and pharmacology of TSPO. Stimulation of TSPO has been shown to have therapeutic use as anxiolytics by inducing allopregnanolone production in the brain, and also potentially for re-establishing androgen levels in hypogonadal ageing animals. Until recently, there has been general agreement regarding the role of TSPO in steroidogenesis. However, recent studies involving genetic depletion of TSPO in mice have created controversy about the role of this protein in steroid and heme synthesis. We review the data on the structure and function of TSPO, as well as the recent results obtained using various genetic animal models. Taken together, these studies suggest that TSPO is a unique mitochondrial pharmacological target for diseases that involve increased mitochondrial activity, including steroidogenesis. Although there is no known mammalian species that lacks TSPO, it is likely that, because of the importance of this ancient protein in evolution and mitochondrial function, redundant mechanisms may exist to replace it under circumstances when it is removed.
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Affiliation(s)
- Vassilios Papadopoulos
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, CA 90089
- Research Institute of the McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Jinjiang Fan
- Research Institute of the McGill University Health Centre and Department of Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - Barry Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland 21205, USA
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