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Shen H, Tu X, Luan X, Zeng Y, He J, Tang W. Serum lipid profiles and post-stroke depression in acute ischemic stroke patients. Neuropsychiatr Dis Treat 2019; 15:1573-1583. [PMID: 31354274 PMCID: PMC6589522 DOI: 10.2147/ndt.s204791] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 05/13/2019] [Indexed: 01/18/2023] Open
Abstract
Purpose: Post-stroke depression (PSD) is a psychiatric complication after stroke that leads to poorer stroke outcomes. Recent observational studies have indicated that lipid profiles were associated with a higher risk of stroke and depression. This study aims to further explore the possible relationship between serum lipid profiles and the development of PSD. Methods: A total of 373 acute ischemic stroke patients were examined. Serum lipid profiles including high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), total cholesterol (TC), apolipoprotein A1 (Apo A1) and apolipoprotein B (Apo B) were measured within 24 hrs of admission. Depression symptoms were assessed by the 17-item Hamilton Depression Scale (HAMD-17) at the one-month follow-up, and HAMD scores ≥7 indicated a diagnosis of PSD. Results: A total of 114 patients were diagnosed with PSD at the one-month follow-up, for a percentage of 30.6%. There were significant differences in HDL-C levels (P<0.001), LDL-C levels (P=0.002) and the LDL/HDL ratio (P<0.001) between the PSD and non-PSD groups, but no differences were observed in TGs, TC, Apo A1 or Apo B. Low serum HDL-C levels (r = -0.157, P<0.001) and elevated LDL-C levels (r =0.139, P=0.002) and the LDL/HDL ratio (r =0.227, P<0.001) were associated with HAMD scores. After adjusting for the NIHSS score, BI score, mRS score and alcohol consumption in the logistic analysis, low HDL-C levels and the highest quartile (≥3.07) of the LDL/HDL ratio were independently associated with the development of PSD (OR =0.250, 95% CI, 0.077-0.813, P=0.021 and OR =1.874, 95% CI, 1.050-3.347, P=0.034, respectively). Conclusion: Decreased levels of HDL-C and elevated levels of LDL/HDL ratio are associated with PSD. HDL-C and the LDL/HDL ratio are independent predictors of PSD.
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Affiliation(s)
- Huiping Shen
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People's Republic of China.,First School of Clinical Medicie, Wenzhou Medical University, Wenzhou, 325000, People's Republic of China
| | - Xinjie Tu
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People's Republic of China
| | - Xiaoqian Luan
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People's Republic of China
| | - Yaying Zeng
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People's Republic of China.,First School of Clinical Medicie, Wenzhou Medical University, Wenzhou, 325000, People's Republic of China
| | - Jincai He
- Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, People's Republic of China
| | - Wenjie Tang
- First School of Clinical Medicie, Wenzhou Medical University, Wenzhou, 325000, People's Republic of China
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52
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Leicaj ML, Pasquini LA, Lima A, Gonzalez Deniselle MC, Pasquini JM, De Nicola AF, Garay LI. Changes in neurosteroidogenesis during demyelination and remyelination in cuprizone-treated mice. J Neuroendocrinol 2018; 30:e12649. [PMID: 30303567 DOI: 10.1111/jne.12649] [Citation(s) in RCA: 14] [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: 05/30/2018] [Revised: 09/20/2018] [Accepted: 10/01/2018] [Indexed: 12/28/2022]
Abstract
Changes of neurosteroids may be involved in the pathophysiology of multiple sclerosis (MS). The present study investigated whether changes of neurosteroidogenesis also occurred in the grey and white matter regions of the brain in mice subjected to cuprizone-induced demyelination. Accordingly, we compared the expression of neurosteroidogenic proteins, including steroidogenic acute regulatory protein (StAR), voltage-dependent anion channel (VDAC) and 18 kDa translocator protein (TSPO), as well as neurosteroidogenic enzymes, including the side chain cleavage enzyme (P450scc), 3β-hydroxysteroid dehydrogenase/isomerase and 5α-reductase (5α-R), during the demyelination and remyelination periods. Using immunohistochemistry and a quantitative polymerase chain reaction, we demonstrated a decreased expression of StAR, P450scc and 5α-R with respect to an increase astrocytic and microglial reaction and elevated levels of tumor necrosis factor (TNF)α during the cuprizone demyelination period in the hippocampus, cortex and corpus callosum. These parameters, as well as the glial reaction, were normalised after 2 weeks of spontaneous remyelination in regions containing grey matter. Conversely, persistent elevated levels of TNFα and low levels of StAR and P450scc were observed during remyelination in corpus callosum white matter. We conclude that neurosteroidogenesis/myelination status and glial reactivity are inversely related in the hippocampus and neocortex. Establishing a cause and effect relationship for the measured variables remains a future challenge for understanding the pathophysiology of MS.
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Affiliation(s)
- María L Leicaj
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
| | - Laura A Pasquini
- Department of Biological Chemistry, School of Pharmacy and Biochemistry, Institute of Chemistry and Biological Physicochemistry (IQUIFIB), University of Buenos Aires and National Research Council (CONICET), Buenos Aires, Argentina
| | - Analia Lima
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
| | - Maria C Gonzalez Deniselle
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
- Department of Physiological Sciences, University of Buenos Aires, Buenos Aires, Argentina
| | - Juana M Pasquini
- Department of Biological Chemistry, School of Pharmacy and Biochemistry, Institute of Chemistry and Biological Physicochemistry (IQUIFIB), University of Buenos Aires and National Research Council (CONICET), Buenos Aires, Argentina
| | - Alejandro F De Nicola
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
- Department of Human Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
| | - Laura I Garay
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental and National Research Council (CONICET), Buenos Aires, Argentina
- Department of Human Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
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53
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Selvaraj V, Stocco DM, Clark BJ. Current knowledge on the acute regulation of steroidogenesis. Biol Reprod 2018; 99:13-26. [PMID: 29718098 PMCID: PMC6044331 DOI: 10.1093/biolre/ioy102] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 02/23/2018] [Accepted: 04/26/2018] [Indexed: 12/31/2022] Open
Abstract
How rapid induction of steroid hormone biosynthesis occurs in response to trophic hormone stimulation of steroidogenic cells has been a subject of intensive investigation for approximately six decades. A key observation made very early was that acute regulation of steroid biosynthesis required swift and timely synthesis of a new protein whose role appeared to be involved in the delivery of the substrate for all steroid hormones, cholesterol, from the outer to the inner mitochondrial membrane where the process of steroidogenesis begins. It was quickly learned that this transfer of cholesterol to the inner mitochondrial membrane was the regulated and rate-limiting step in steroidogenesis. Following this observation, the quest for this putative regulator protein(s) began in earnest in the late 1950s. This review provides a history of this quest, the candidate proteins that arose over the years and facts surrounding their rise or decline. Only two have persisted-translocator protein (TSPO) and the steroidogenic acute regulatory protein (StAR). We present a detailed summary of the work that has been published for each of these two proteins, the specific data that has appeared in support of their role in cholesterol transport and steroidogenesis, and the ensuing observations that have arisen in recent years that have refuted the role of TSPO in this process. We believe that the only viable candidate that has been shown to be indispensable is the StAR protein. Lastly, we provide our view on what may be the most important questions concerning the acute regulation of steroidogenesis that need to be asked in future.
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Affiliation(s)
- Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York, USA
| | - Douglas M Stocco
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
| | - Barbara J Clark
- Department of Biochemistry and Molecular Genetics, University of Louisville, Louisville, Kentucky, USA
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54
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Rashid K, Wolf A, Langmann T. Microglia Activation and Immunomodulatory Therapies for Retinal Degenerations. Front Cell Neurosci 2018; 12:176. [PMID: 29977192 PMCID: PMC6021747 DOI: 10.3389/fncel.2018.00176] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/05/2018] [Indexed: 01/05/2023] Open
Abstract
A chronic pro-inflammatory environment is a hallmark of retinal degenerative diseases and neurological disorders that affect vision. Inflammatory responses during retinal pathophysiology are orchestrated by microglial cells which constitute the resident immune cell population. Following activation, microglia cells lose their ramified protrusions, proliferate and rapidly migrate to the damaged areas and resolve tissue damage. However, sustained presence of tissue stress primes microglia to become overreactive and results in the excessive production of pro-inflammatory mediators that favor retinal degenerative changes. Consequently, interventions aimed at overriding microglial pro-inflammatory and pro-oxidative properties may attenuate photoreceptor demise and preserve retinal integrity. We highlight the positive effects of ligands for the translocator protein 18 kDa (TSPO) and the cytokine interferon beta (IFN-β) in modulating microgliosis during retinal pathologies and discuss their plausible mechanisms of action.
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Affiliation(s)
- Khalid Rashid
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Anne Wolf
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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55
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Pantaleão L, Rocha GHO, Reutelingsperger C, Tiago M, Maria-Engler SS, Solito E, Farsky SP. Connections of annexin A1 and translocator protein-18 kDa on toll like receptor stimulated BV-2 cells. Exp Cell Res 2018; 367:282-290. [DOI: 10.1016/j.yexcr.2018.04.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 04/06/2018] [Accepted: 04/07/2018] [Indexed: 01/27/2023]
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56
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Biswas L, Zhou X, Dhillon B, Graham A, Shu X. Retinal pigment epithelium cholesterol efflux mediated by the 18 kDa translocator protein, TSPO, a potential target for treating age-related macular degeneration. Hum Mol Genet 2018; 26:4327-4339. [PMID: 28973423 DOI: 10.1093/hmg/ddx319] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 08/06/2017] [Indexed: 12/13/2022] Open
Abstract
Cholesterol accumulation beneath the retinal pigment epithelium (RPE) cells is supposed to contribute the pathogenesis of age-related macular degeneration (AMD). Cholesterol efflux genes (APOE and ABCA1) were identified as risk factors for AMD, although how cholesterol efflux influences accumulation of this lipid in sub-RPE deposits remains elusive. The 18 kDa translocator protein, TSPO, is a cholesterol-binding protein implicated in mitochondrial cholesterol transport. Here, we investigate the function of TSPO in cholesterol efflux from the RPE cells. We demonstrate in RPE cells that TSPO specific ligands promoted cholesterol efflux to acceptor (apo)lipoprotein and human serum, while loss of TSPO resulted in impaired cholesterol efflux. TSPO-/- RPE cells also had significantly increased production of reactive oxygen species (ROS) and upregulated expression of proinflammatory cytokines (IL-1β and TNFα). Cholesterol (oxidized LDL) uptake and accumulation were markedly increased in TSPO-/- RPE cells. Finally, in aged RPE cells, TSPO expression was reduced and cholesterol efflux impaired. These findings provide a new pharmacological concept to treat early AMD patients by stimulating cellular cholesterol removal with TSPO specific ligands or by overexpression of TSPO in RPE cells.
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Affiliation(s)
- Lincoln Biswas
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4?0BA, UK
| | - Xinzhi Zhou
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4?0BA, UK
| | - Baljean Dhillon
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16?4SB, UK
| | - Annette Graham
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4?0BA, UK
| | - Xinhua Shu
- Department of Life Sciences, Glasgow Caledonian University, Glasgow G4?0BA, UK
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57
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De Nicola AF, Garay LI, Meyer M, Guennoun R, Sitruk-Ware R, Schumacher M, Gonzalez Deniselle MC. Neurosteroidogenesis and progesterone anti-inflammatory/neuroprotective effects. J Neuroendocrinol 2018; 30. [PMID: 28675779 DOI: 10.1111/jne.12502] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 12/19/2022]
Abstract
Progesterone shows anti-inflammatory and promyelinating effects in mice with experimental autoimmune encephalomyelitis (EAE), a commonly used model for multiple sclerosis (MS). Because neurosteroids have been implicated as protective factors for MS and EAE, we analysed the expression of neurosteroidogenic enzymes in the compromised spinal cord of EAE mice. EAE was induced in female C57Bl6 mice, which were then killed on day 16 after induction. Progesterone was given by pellet implantation 1 week before EAE induction. Untreated EAE mice showed decreased mRNAs for the steroidogenic acute regulatory protein (Star), voltage-dependent anion channel (VDAC), cholesterol side-chain cleavage (P450scc), 5α-reductase, 3α-hydroxysteroid dehydrogenase (3α-HSOR) and aromatase, whereas changes of 3β-hydroxysteroid dehydrogenase (3β-HSD) were not significant. mRNA translocator protein (18 kDa) (TSPO) was elevated, concomitantly with a reactive microgliosis. EAE mice also showed abnormal mitochondrial ultrastructure in axons and neuronal bodies, as well as reduced expression of fission and fusion protein mRNAs. Progesterone pretreatment before EAE induction increased Star, VDAC, P450scc, 5α-reductase type I, 3α-HSOR and aromatase mRNAs and did not modify 3β-HSD. TSPO mRNA was decreased, possibly as a result of reversal of microgliosis. Progesterone pretreatment also improved mitochondrial ultrastructure and increased fission/fusion protein mRNAs. These mitochondrial effects may be part of the progesterone recovery of neurosteroidogenesis. The enzymes 3β-HSD, 3α-HSOR and 5α-reductase are also responsible for the formation of androgens. Because MS patients and EAE rodents show changes of central androgen levels, it is likely that, together with progestins and oestrogens, neuroandrogens afford neuroprotection for EAE and MS. The data reviewed suggest that enhanced synthesis of neurosteroids contributes in an auto/paracrine manner to reinforce the neuroprotective and anti-inflammatory effects of exogenous progesterone given to EAE mice.
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Affiliation(s)
- A F De Nicola
- Department of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina
- Instituto de Biologia y Medicina Experimental-CONICET, Buenos Aires, Argentina
| | - L I Garay
- Department of Human Biochemistry, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina
- Instituto de Biologia y Medicina Experimental-CONICET, Buenos Aires, Argentina
| | - M Meyer
- Instituto de Biologia y Medicina Experimental-CONICET, Buenos Aires, Argentina
| | - R Guennoun
- U1195 Inserm and Université Paris-Sud, Le Kremlin-Bicêtre, France
| | | | - M Schumacher
- U1195 Inserm and Université Paris-Sud, Le Kremlin-Bicêtre, France
| | - M C Gonzalez Deniselle
- The Population Council, New York, NY, USA
- Department of Physiology and Biophysics, Faculty of Medicine, University of Buenos Aires, Buenos Aires, Argentina
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58
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Fan J, Wang K, Zirkin B, Papadopoulos V. CRISPR/Cas9‒Mediated Tspo Gene Mutations Lead to Reduced Mitochondrial Membrane Potential and Steroid Formation in MA-10 Mouse Tumor Leydig Cells. Endocrinology 2018; 159:1130-1146. [PMID: 29300865 PMCID: PMC5793793 DOI: 10.1210/en.2017-03065] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/21/2017] [Indexed: 12/17/2022]
Abstract
The outer mitochondrial membrane translocator protein (TSPO) binds cholesterol with high affinity and is involved in mediating its delivery into mitochondria, the rate-limiting step in hormone-induced steroidogenesis. Specific ligand binding to TSPO has been shown to initiate steroid formation. However, recent studies of the genetic deletion of Tspo have provided conflicting results. Here, we address and extend previous studies by examining the effects of Tspo-specific mutations on steroid formation in hormone- and cyclic adenosine monophosphate (cAMP)-responsive MA-10 cells, using the CRISPR/Cas9 system. Two mutant subcell lines, nG1 and G2G, each carrying a Tspo exon2-specific genome modification, and two control subcell lines, G1 and HH, each carrying a wild-type Tspo, were produced. In response to dibutyryl cAMP, the nG1 and G2G cells produced progesterone at levels significantly lower than those produced by the corresponding control cells G1 and HH. Neutral lipid homeostasis, which provides free cholesterol for steroid biosynthesis, was altered significantly in the Tspo mutant cells. Interestingly, the mitochondrial membrane potential (ΔΨm) of the Tspo mutant cells was significantly reduced compared with that of the control cells, likely because of TSPO interactions with the voltage-dependent anion channel and tubulin at the outer mitochondrial membrane. Steroidogenic acute regulatory protein (STAR) expression was induced in nG1 cells, suggesting that reduced TSPO affected STAR synthesis and/or processing. Taken together, these results provide further evidence for the critical role of TSPO in steroid biosynthesis and suggest that it may function at least in part via its regulation of ΔΨm and effects on STAR.
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Affiliation(s)
- Jinjiang Fan
- Research Institute of the McGill University Health Centre and Department of Medicine, Faculty of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Kevin Wang
- Research Institute of the McGill University Health Centre and Department of Medicine, Faculty 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
| | - Vassilios Papadopoulos
- Research Institute of the McGill University Health Centre and Department of Medicine, Faculty of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
- Department of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, California 90089
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Tugaeva KV, Faletrov YV, Allakhverdiev ES, Shkumatov VM, Maksimov EG, Sluchanko NN. Effect of the NBD-group position on interaction of fluorescently-labeled cholesterol analogues with human steroidogenic acute regulatory protein STARD1. Biochem Biophys Res Commun 2018; 497:58-64. [DOI: 10.1016/j.bbrc.2018.02.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 02/02/2018] [Indexed: 10/18/2022]
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60
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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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61
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Steroidogenic abnormalities in translocator protein knockout mice and significance in the aging male. Biochem J 2018; 475:75-85. [PMID: 29127254 DOI: 10.1042/bcj20170645] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 11/07/2017] [Accepted: 11/09/2017] [Indexed: 11/17/2022]
Abstract
The translocator protein (TSPO) has been proposed to act as a key component in a complex important for mitochondrial cholesterol importation, which is the rate-limiting step in steroid hormone synthesis. However, TSPO function in steroidogenesis has recently been challenged by the development of TSPO knockout (TSPO-KO) mice, as they exhibit normal baseline gonadal testosterone and adrenal corticosteroid production. Here, we demonstrate that despite normal androgen levels in young male TSPO-KO mice, TSPO deficiency alters steroidogenic flux and results in reduced total steroidogenic output. Specific reductions in the levels of progesterone and corticosterone as well as age-dependent androgen deficiency were observed in both young and aged male TSPO-KO mice. Collectively, these findings indicate that while TSPO is not critical for achieving baseline testicular and adrenal steroidogenesis, either indirect effects of TSPO on steroidogenic processes, or compensatory mechanisms and functional redundancy, lead to subtle steroidogenic abnormalities which become exacerbated with aging.
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62
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Holmberg E, Sjöstedt J, Malinina E, Johansson M, Turkmen S, Ragagnin G, Lundqvist A, Löfgren M, Jaukkuri L, Bixo M, Bäckström T. Allopregnanolone involvement in feeding regulation, overeating and obesity. Front Neuroendocrinol 2018; 48:70-77. [PMID: 28694181 DOI: 10.1016/j.yfrne.2017.07.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 07/04/2017] [Accepted: 07/05/2017] [Indexed: 01/19/2023]
Abstract
Obesity is strongly associated with ill health, primarily caused by consumption of excessive calories, and promoted (inter alia) by gamma-amino-butyric-acid (GABA) stimulating food intake by activating GABAA receptors (primarily with α3 and α2 subunits) in the hypothalamic arcuate nucleus and paraventricular nucleus. Allopregnanolone is a potent positive GABAA receptor modulating steroid (GAMS). As reviewed here, elevated allopregnanolone levels are associated with increases in food intake, preferences for energy-rich food, and obesity in humans and other mammals. In women with polycystic ovarian disease, high serum allopregnanolone concentrations are linked to uncontrolled eating, and perturbed sensitivity to allopregnanolone. Increases in weight during pregnancy also correlate with increases in allopregnanolone levels. Moreover, Prader-Willis syndrome is associated with massive overeating, absence of a GABAA receptor (with compensatory >12-, >5- and >1.5-fold increases in α4, γ2, and α1, α3 subunits), and increases in the α4, βx, δ receptor subtype, which is highly sensitive to allopregnanolone. GABA and positive GABA-A receptor modulating steroids like allopregnanolone stimulates food intake and weight gain.
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Affiliation(s)
- E Holmberg
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - J Sjöstedt
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - E Malinina
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - M Johansson
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - S Turkmen
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - G Ragagnin
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - A Lundqvist
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - M Löfgren
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - L Jaukkuri
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - M Bixo
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden
| | - T Bäckström
- Umeå Neurosteroid Research Center, Department of Clinical Sciences, Obstetrics and Gynecology, Umeå University, SE-901 85 Umeå, Sweden.
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Gaignard P, Liere P, Thérond P, Schumacher M, Slama A, Guennoun R. Role of Sex Hormones on Brain Mitochondrial Function, with Special Reference to Aging and Neurodegenerative Diseases. Front Aging Neurosci 2017; 9:406. [PMID: 29270123 PMCID: PMC5725410 DOI: 10.3389/fnagi.2017.00406] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 11/24/2017] [Indexed: 01/18/2023] Open
Abstract
The mitochondria have a fundamental role in both cellular energy supply and oxidative stress regulation and are target of the effects of sex steroids, particularly the neuroprotective ones. Aging is associated with a decline in the levels of different steroid hormones, and this decrease may underline some neural dysfunctions. Besides, modifications in mitochondrial functions associated with aging processes are also well documented. In this review, we will discuss studies that describe the modifications of brain mitochondrial function and of steroid levels associated with physiological aging and with neurodegenerative diseases. A special emphasis will be placed on describing and discussing our recent findings concerning the concomitant study of mitochondrial function (oxidative phosphorylation, oxidative stress) and brain steroid levels in both young (3-month-old) and aged (20-month-old) male and female mice.
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Affiliation(s)
- Pauline Gaignard
- U1195 Inserm and University Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France
- Biochemistry Laboratory, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France
| | - Philippe Liere
- U1195 Inserm and University Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Patrice Thérond
- Biochemistry Laboratory, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France
| | - Michael Schumacher
- U1195 Inserm and University Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Abdelhamid Slama
- Biochemistry Laboratory, Bicêtre Hospital, Assistance Publique-Hôpitaux de Paris, Le Kremlin-Bicêtre, France
| | - Rachida Guennoun
- U1195 Inserm and University Paris-Sud and University Paris-Saclay, Le Kremlin-Bicêtre, France
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64
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Adrenal Oncocytic Neoplasm with Paradoxical Loss of Important Mitochondrial Steroidogenic Protein: The 18 kDA Translocator Protein. Case Rep Endocrinol 2017; 2017:6734695. [PMID: 29318061 PMCID: PMC5727653 DOI: 10.1155/2017/6734695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 10/20/2017] [Accepted: 10/31/2017] [Indexed: 12/04/2022] Open
Abstract
The adrenal glands produce a variety of hormones that play a key role in the regulation of blood pressure, electrolyte homeostasis, metabolism, immune system suppression, and the body's physiologic response to stress. Adrenal neoplasms can be asymptomatic or can overproduce certain hormones that lead to different clinical manifestations. Oncocytic adrenal neoplasms are infrequent tumors that arise from cells in the adrenal cortex and display a characteristic increase in the number of cytoplasmic mitochondria. Since the rate-limiting step in steroidogenesis includes the transport of cholesterol across the mitochondrial membranes, in part carried out by the 18-kDa translocator protein (TSPO), we assessed the expression of TSPO in a case of adrenal oncocytic neoplasm using residual adrenal gland of the patient as internal control. We observed a significant loss of TSPO immunofluorescence expression in the adrenal oncocytic tumor cells when compared to adjacent normal adrenal tissue. We further confirmed this finding by employing Western blot analysis to semiquantify TSPO expression in tumor and normal adrenal cells. Our findings could suggest a potential role of TSPO in the tumorigenesis of this case of adrenocortical oncocytic neoplasm.
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65
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TSPO mutations in rats and a human polymorphism impair the rate of steroid synthesis. Biochem J 2017; 474:3985-3999. [PMID: 29074640 PMCID: PMC5697202 DOI: 10.1042/bcj20170648] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/20/2017] [Accepted: 10/25/2017] [Indexed: 01/08/2023]
Abstract
The 18 kDa translocator protein (TSPO) is a ubiquitous conserved outer mitochondrial membrane protein implicated in numerous cell and tissue functions, including steroid hormone biosynthesis, respiration, cell proliferation, and apoptosis. TSPO binds with high affinity to cholesterol and numerous compounds, is expressed at high levels in steroid-synthesizing tissues, and mediates cholesterol import into mitochondria, which is the rate-limiting step in steroid formation. In humans, the rs6971 polymorphism on the TSPO gene leads to an amino acid substitution in the fifth transmembrane loop of the protein, which is where the cholesterol-binding domain of TSPO is located, and this polymorphism has been associated with anxiety-related disorders. However, recent knockout mouse models have provided inconsistent conclusions of whether TSPO is directly involved in steroid synthesis. In this report, we show that TSPO deletion mutations in rat and its corresponding rs6971 polymorphism in humans alter adrenocorticotropic hormone-induced plasma corticosteroid concentrations. Rat tissues examined show increased cholesteryl ester accumulation, and neurosteroid formation was undetectable in homozygous rats. These results also support a role for TSPO ligands in diseases with steroid-dependent stress and anxiety elements.
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66
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Regulation of Mitochondrial, Cellular, and Organismal Functions by TSPO. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 82:103-136. [PMID: 29413517 DOI: 10.1016/bs.apha.2017.09.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
In 1999, the enigma of the 18kDa mitochondrial translocator protein (TSPO), also known as the peripheral-type benzodiazepine receptor, was the seeming disparity of the many functions attributed to TSPO, ranging from the potential of TSPO acting as a housekeeping gene at molecular biological levels to adaptations to stress, and even involvement in higher emotional and cognitive functioning, such as anxiety and depression. In the years since then, knowledge regarding the many functions modulated by TSPO has expanded, and understanding has deepened. In addition, new functions could be firmly associated with TSPO, such as regulation of programmed cell death and modulation of gene expression. Interestingly, control by the mitochondrial TSPO over both of these life and death functions appears to include Ca++ homeostasis, generation of reactive oxygen species (ROS), and ATP production. Other mitochondrial functions under TSPO control are considered to be steroidogenesis and tetrapyrrole metabolism. As TSPO effects on gene expression and on programmed cell death can be related to the wide range of functions that can be associated with TSPO, several of these five elements of Ca++, ROS, ATP, steroids, and tetrapyrroles may indeed form the basis of TSPO's capability to operate as a multifunctional housekeeping gene to maintain homeostasis of the cell and of the whole multicellular organism.
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67
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Kreisl WC, Henter ID, Innis RB. Imaging Translocator Protein as a Biomarker of Neuroinflammation in Dementia. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 82:163-185. [PMID: 29413519 PMCID: PMC6190574 DOI: 10.1016/bs.apha.2017.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neuroinflammation has long been considered a potential contributor to neurodegenerative disorders that result in dementia. Accumulation of abnormal protein aggregates in Alzheimer's disease, frontotemporal dementia, and dementia with Lewy bodies is associated with the activation of microglia and astrocytes into proinflammatory states, and chronic low-level activation of glial cells likely contributes to the pathological changes observed in these and other neurodegenerative diseases. The 18kDa translocator protein (TSPO) is a key biomarker for measuring inflammation in the brain via positron emission tomography (PET). Increased TSPO density has been observed in brain tissue from patients with neurodegenerative diseases and colocalizes to activated microglia and reactive astrocytes. Several radioligands have been developed to measure TSPO density in vivo with PET, and these have been used in clinical studies of different dementia syndromes. However, TSPO radioligands have limitations, including low specific-to-nonspecific signal and differential affinity to a polymorphism on the TSPO gene, which must be taken into consideration in designing and interpreting human PET studies. Nonetheless, most PET studies have shown that increased TSPO binding is associated with various dementias, suggesting that TSPO has potential as a biomarker to further explore the role of neuroinflammation in dementia pathogenesis and may prove useful in monitoring disease progression.
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Affiliation(s)
- William C Kreisl
- Taub Institute, Columbia University Medical Center, New York, NY, United States.
| | - Ioline D Henter
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, United States
| | - Robert B Innis
- Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD, United States
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68
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Musman J, Paradis S, Panel M, Pons S, Barau C, Caccia C, Leoni V, Ghaleh B, Morin D. A TSPO ligand prevents mitochondrial sterol accumulation and dysfunction during myocardial ischemia-reperfusion in hypercholesterolemic rats. Biochem Pharmacol 2017. [DOI: 10.1016/j.bcp.2017.06.125] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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69
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Milite C, Barresi E, Da Pozzo E, Costa B, Viviano M, Porta A, Messere A, Sbardella G, Da Settimo F, Novellino E, Cosconati S, Castellano S, Taliani S, Martini C. Exploiting the 4-Phenylquinazoline Scaffold for the Development of High Affinity Fluorescent Probes for the Translocator Protein (TSPO). J Med Chem 2017; 60:7897-7909. [DOI: 10.1021/acs.jmedchem.7b01031] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Ciro Milite
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
| | - Elisabetta Barresi
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Eleonora Da Pozzo
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Barbara Costa
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Monica Viviano
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
| | - Amalia Porta
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
| | - Anna Messere
- DiSTABiF, University of Campania Luigi Vanvitelli, 81100 Caserta, Italy
| | - Gianluca Sbardella
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
| | - Federico Da Settimo
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Ettore Novellino
- Dipartimento
di Farmacia, Università di Napoli “Federico II”, Via D. Montesano 49, 80131 Napoli, Italy
| | - Sandro Cosconati
- DiSTABiF, University of Campania Luigi Vanvitelli, 81100 Caserta, Italy
| | - Sabrina Castellano
- Dipartimento
di Farmacia, Università di Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Salerno, Italy
- Dipartimento
di Medicina, Chirurgia e Odontoiatria “Scuola Medica Salernitana”, Università di Salerno, Via Salvador Allende, I-84081 Baronissi, Salerno, Italy
| | - Sabrina Taliani
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
| | - Claudia Martini
- Dipartimento
di Farmacia, Università di Pisa, Via Bonanno 6, 56126 Pisa, Italy
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70
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Leva G, Klein C, Benyounes J, Hallé F, Bihel F, Collongues N, De Seze J, Mensah-Nyagan AG, Patte-Mensah C. The translocator protein ligand XBD173 improves clinical symptoms and neuropathological markers in the SJL/J mouse model of multiple sclerosis. Biochim Biophys Acta Mol Basis Dis 2017; 1863:3016-3027. [PMID: 28899788 DOI: 10.1016/j.bbadis.2017.09.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 09/04/2017] [Accepted: 09/08/2017] [Indexed: 12/18/2022]
Abstract
Multiple sclerosis (MS) is a severe autoimmune disease characterized by inflammatory, demyelinating and neurodegenerative components causing motor, sensory, visual and/or cognitive symptoms. The relapsing-remitting MS affecting 85% of patients is reliably mimicked by the proteolipid-protein (PLP)-induced experimental autoimmune encephalomyelitis (EAE) SJL/J-mouse model. Significant progress was made for MS treatment but the development of effective therapies devoid of severe side-effects remains a great challenge. Here, we combine clinical, behavioral, histopathological, biochemical and molecular approaches to demonstrate that low and well tolerated doses (10-20mg/kg) of TSPO ligand XBD173 (Emapunil) efficiently ameliorate clinical signs and neuropathology of PLP-EAE mice. In addition to the conventional clinical scoring of symptoms, we applied the robust behavioral Catwalk-method to confirm that XBD173 (10mg/kg) increases the maximum contact area parameter at EAE-disease peak, indicating an improvement/recovery of motor functions. Consistently, histopathological studies coupled with microscope-cellSens quantification and RT-qPCR analyzes showed that XBD173 prevented demyelination by restoring normal protein and mRNA levels of myelin basic protein that was significantly repressed in PLP-EAE mice spinal cord and brain. Interestingly, ELISA-based measurement revealed that XBD173 increased allopregnanolone concentrations in PLP-EAE mice spinal and brain tissues. Furthermore, flow cytometry assessment demonstrated that XBD173 therapy decreased serum level of pro-inflammatory cytokines, including interleukin-17A, Interleukin-6 and tumor-necrosis-factor alpha in PLP-EAE mice. As the optimal XBD173 dosing exerting the maximal beneficial action in EAE mice is the lower 10mg/kg dose, the paper opens interesting perspectives for the development of efficient and safe therapies against MS with slight or no side-effects.
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Affiliation(s)
- Géraldine Leva
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67 000 Strasbourg, France
| | - Christian Klein
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67 000 Strasbourg, France
| | - Jérémie Benyounes
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67 000 Strasbourg, France
| | - François Hallé
- Laboratoire d'innovation thérapeutique (LIT) CNRS UMR 7200, Faculté de Pharmacie de Strasbourg, 74 route du Rhin, CS 60024, 67401 Illkirch Cedex, France
| | - Frédéric Bihel
- Laboratoire d'innovation thérapeutique (LIT) CNRS UMR 7200, Faculté de Pharmacie de Strasbourg, 74 route du Rhin, CS 60024, 67401 Illkirch Cedex, France
| | - Nicolas Collongues
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67 000 Strasbourg, France
| | - Jérôme De Seze
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67 000 Strasbourg, France
| | - Ayikoe-Guy Mensah-Nyagan
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67 000 Strasbourg, France.
| | - Christine Patte-Mensah
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment 3 de la Faculté de Médecine, 11 rue Humann, 67 000 Strasbourg, France.
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71
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Wang Y, Chen F, Ye L, Zirkin B, Chen H. Steroidogenesis in Leydig cells: effects of aging and environmental factors. Reproduction 2017; 154:R111-R122. [PMID: 28747539 DOI: 10.1530/rep-17-0064] [Citation(s) in RCA: 144] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 07/14/2017] [Accepted: 07/26/2017] [Indexed: 12/28/2022]
Abstract
Serum testosterone (TS) levels decrease with aging in both humans and rodents. Using the rat as a model system, it was found that age-related reductions in serum TS were not due to loss of Leydig cells, but rather to the reduced ability of the Leydig cells to produce TS in response to luteinizing hormone (LH). Detailed analyses of the steroidogenic pathway have suggested that two defects along the pathway, LH-stimulated cAMP production and cholesterol transport to and into the mitochondria, are of particular importance in age-related reductions in TS production. Although the mechanisms involved in these defects are far from certain, increasing oxidative stress appears to play a particularly important role. Interestingly, increased oxidative stress also appears to be involved in the suppressive effects of endocrine disruptors on Leydig cell TS production.
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Affiliation(s)
- Yiyan Wang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical UniversityWenzhou, Zhejiang, China.,Department of Biochemistry and Molecular BiologyJohns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Fenfen Chen
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical UniversityWenzhou, Zhejiang, China
| | - Leping Ye
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical UniversityWenzhou, Zhejiang, China
| | - Barry Zirkin
- Department of Biochemistry and Molecular BiologyJohns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Haolin Chen
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical UniversityWenzhou, Zhejiang, China .,Department of Biochemistry and Molecular BiologyJohns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
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72
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Schain M, Kreisl WC. Neuroinflammation in Neurodegenerative Disorders—a Review. Curr Neurol Neurosci Rep 2017; 17:25. [DOI: 10.1007/s11910-017-0733-2] [Citation(s) in RCA: 187] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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73
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Chien Y, Rosal K, Chung BC. Function of CYP11A1 in the mitochondria. Mol Cell Endocrinol 2017; 441:55-61. [PMID: 27815210 DOI: 10.1016/j.mce.2016.10.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 10/27/2016] [Accepted: 10/27/2016] [Indexed: 01/08/2023]
Abstract
Steroids are synthesized from the adrenal glands and gonads by enzymes of the cytochromes P450 and hydroxysteroid dehydrogenase in nature. These enzymes are located in the membrane of endoplasmic reticulum and mitochondria to catalyze redox reactions using electrons transported from the membrane. In the mitochondria, steroidogenic enzymes are inserted into the inner membrane with the bulk of the protein facing the matrix. They are not only important for steroid biosynthesis, their presence also affects mitochondrial morphology. Mitochondria undergo constant fission and fusion; they play important roles in energy production, apoptosis, and metabolism. Their defects often lead to human diseases. Mitochondrial cristae are usually lamellar in shape, but can also assume different shapes. Cristae in the mitochondria of steroidogenic cells are tubular-vesicular in shape. This cristae shape is also related to the degree of steroidogenic cell differentiation. Steroidogenic enzymes in the mitochondria appear to have a dual role in shaping the morphology of mitochondria and in steroid production.
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Affiliation(s)
- Yu Chien
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Karen Rosal
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Bon-Chu Chung
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.
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74
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Stocco DM, Zhao AH, Tu LN, Morohaku K, Selvaraj V. A brief history of the search for the protein(s) involved in the acute regulation of steroidogenesis. Mol Cell Endocrinol 2017; 441:7-16. [PMID: 27484452 PMCID: PMC5929480 DOI: 10.1016/j.mce.2016.07.036] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/26/2016] [Accepted: 07/26/2016] [Indexed: 12/14/2022]
Abstract
The synthesis of steroid hormones occurs in specific cells and tissues in the body in response to trophic hormones and other signals. In order to synthesize steroids de novo, cholesterol, the precursor of all steroid hormones, must be mobilized from cellular stores to the inner mitochondrial membrane (IMM) to be converted into the first steroid formed, pregnenolone. This delivery of cholesterol to the IMM is the rate-limiting step in this process, and has long been known to require the rapid synthesis of a new protein(s) in response to stimulation. Although several possibilities for this protein have arisen over the past few decades, most of the recent attention to fill this role has centered on the candidacies of the proteins the Translocator Protein (TSPO) and the Steroidogenic Acute Regulatory Protein (StAR). In this review, the process of regulating steroidogenesis is briefly described, the characteristics of the candidate proteins and the data supporting their candidacies summarized, and some recent findings that propose a serious challenge for the role of TSPO in this process are discussed.
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Affiliation(s)
- Douglas M Stocco
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA.
| | - Amy H Zhao
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Lan N Tu
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Kanako Morohaku
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Vimal Selvaraj
- Department of Animal Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
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75
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Garay L, Gonzalez Giqueaux P, Guennoun R, Schumacher M, Gonzalez Deniselle MC, De Nicola AF. Progesterone treatment modulates mRNA OF neurosteroidogenic enzymes in a murine model of multiple sclerosis. J Steroid Biochem Mol Biol 2017; 165:421-429. [PMID: 27597394 DOI: 10.1016/j.jsbmb.2016.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/29/2016] [Accepted: 09/01/2016] [Indexed: 11/20/2022]
Abstract
Previous studies of experimental autoimmune encephalomyelitis (EAE) have shown that progesterone decreases inflammatory cell infiltration and proinflammatory factors, increases myelination and attenuates clinical grade of EAE mice. To elucidate potential mediators of these effects, we analyzed the mRNA expression of neurosteroidogenic enzymes in the spinal cord, in view of the protective role of steroids in EAE. We also analyzed mitochondrial morphology and dynamics (fusion and fission proteins), considering the role of mitochondria in neurosteroidogenesis. EAE was induced in C57Bl6 mice using MOG40-54 and killed on day 16 after induction. Using qPCR, we found in steroid-untreated EAE mice decreased mRNAs for the steroidogenic acute regulatory protein (Star), voltage-dependent anion channel (VDAC), P450scc (cholesterol side-chain cleavage), 5α-reductase, 3α-hydroxysteroid dehydrogenase (3α-HSD) and aromatase, whereas levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) showed a large intra-group variance. We also found increased mRNA expression of 18Kd translocator protein (TSPO), which likely resulted from the reactive microgliosis in this model. EAE mice also showed pathological mitochondrial morphology and reduced expression of fission and fusion protein mRNAs. Most importantly, pretreatment with progesterone a week before EAE induction increased Star,VDAC, P450scc, 5α-reductase type I, 3α-HSD and aromatase mRNAs and did not modify 3β-HSD. TSPO mRNA was decreased, consequent with the inhibition of microgliosis. Mitochondrial morphology was improved and fission/fusion protein mRNAs were enhanced by progesterone treatment. Furthermore, progesterone protective effects on mitochondrial and endoplasmic reticulum may allow the recovery of neurosteroidogenesis. In this way, endogenously synthesized neurosteroids may reinforce the beneficial effects of exogenous progesterone previously shown in MS mice.
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Affiliation(s)
- Laura Garay
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Buenos Aires, Argentina; Dept. of Human Biochemistry(,) Faculty of Medicine, University of Buenos Aires, Argentina
| | - Paula Gonzalez Giqueaux
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Buenos Aires, Argentina
| | - Rachida Guennoun
- U1195 Inserm and University Paris-Sud and University Paris-Saclay, Kremlin-Bicêtre, France
| | - Michael Schumacher
- U1195 Inserm and University Paris-Sud and University Paris-Saclay, Kremlin-Bicêtre, France
| | - Maria Claudia Gonzalez Deniselle
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Buenos Aires, Argentina; Dept. of Human Physiology, Faculty of Medicine, University of Buenos Aires, Argentina
| | - Alejandro F De Nicola
- Laboratory of Neuroendocrine Biochemistry, Instituto de Biologia y Medicina Experimental, Buenos Aires, Argentina; Dept. of Human Biochemistry(,) Faculty of Medicine, University of Buenos Aires, Argentina.
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Abstract
Adrenocorticotropin hormone (ACTH) produced by the anterior pituitary stimulates glucocorticoid synthesis by the adrenal cortex. The first step in glucocorticoid synthesis is the delivery of cholesterol to the mitochondrial matrix where the first enzymatic reaction in the steroid hormone biosynthetic pathway occurs. A key response of adrenal cells to ACTH is activation of the cAMP-protein kinase A (PKA) signaling pathway. PKA activation results in an acute increase in expression and function of the Steroidogenic Acute Regulatory protein (StAR). StAR plays an essential role in steroidogenesis- it controls the hormone-dependent movement of cholesterol across the mitochondrial membranes. Currently StAR's mechanism of action remains a major unanswered question in the field. However, some insight may be gained from understanding the mechanism(s) controlling the PKA-dependent phosphorylation of StAR at S194/195 (mouse/human StAR), a modification that is required for function. This mini-review provides a background on StAR's biology with a focus on StAR phosphorylation. The model for StAR translation and phosphorylation at the outer mitochondrial membrane, the location for StAR function, is presented to highlight a unifying theme emerging from diverse studies.
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Affiliation(s)
- Barbara J Clark
- Department of Biochemistry and Molecular Genetics, University of Louisville Louisville, KY, USA
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77
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Selvaraj V, Tu LN. Current status and future perspectives: TSPO in steroid neuroendocrinology. J Endocrinol 2016; 231:R1-R30. [PMID: 27422254 DOI: 10.1530/joe-16-0241] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 07/15/2016] [Indexed: 12/21/2022]
Abstract
The mitochondrial translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor (PBR), has received significant attention both as a diagnostic biomarker and as a therapeutic target for different neuronal disease pathologies. Recently, its functional basis believed to be mediating mitochondrial cholesterol import for steroid hormone production has been refuted by studies examining both in vivo and in vitro genetic Tspo-deficient models. As a result, there now exists a fundamental gap in the understanding of TSPO function in the nervous system, and its putative pharmacology in neurosteroid production. In this review, we discuss several recent findings in steroidogenic cells that are in direct contradiction to previous studies, and necessitate a re-examination of the purported role for TSPO in de novo neurosteroid biosynthesis. We critically examine the pharmacological effects of different TSPO-binding drugs with particular focus on studies that measure neurosteroid levels. We highlight the basis of key misconceptions regarding TSPO that continue to pervade the literature, and the need for interpretation with caution to avoid negative impacts. We also summarize the emerging perspectives that point to new directions that need to be investigated for understanding the molecular function of TSPO, only after which the true potential of this therapeutic target in medicine may be realized.
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Affiliation(s)
- Vimal Selvaraj
- Department of Animal ScienceCornell University, Ithaca, New York, USA
| | - Lan N Tu
- Department of Animal ScienceCornell University, Ithaca, New York, USA
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78
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TSPO ligands stimulate ZnPPIX transport and ROS accumulation leading to the inhibition of P. falciparum growth in human blood. Sci Rep 2016; 6:33516. [PMID: 27641616 PMCID: PMC5027585 DOI: 10.1038/srep33516] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 08/30/2016] [Indexed: 11/08/2022] Open
Abstract
After invading red blood cells (RBCs), Plasmodium falciparum (Pf) can export its own proteins to the host membrane and activate endogenous channels that are present in the membrane of RBCs. This transport pathway involves the Voltage Dependent Anion Channel (VDAC). Moreover, ligands of the VDAC partner TranSlocator PrOtein (TSPO) were demonstrated to inhibit the growth of the parasite. We studied the expression of TSPO and VDAC isoforms in late erythroid precursors, examined the presence of these proteins in membranes of non-infected and infected human RBCs, and evaluated the efficiency of TSPO ligands in inhibiting plasmodium growth, transporting the haem analogue Zn-protoporphyrin-IX (ZnPPIX) and enhancing the accumulation of reactive oxygen species (ROS). TSPO and VDAC isoforms are differentially expressed on erythroid cells in late differentiation states. TSPO2 and VDAC are present in the membranes of mature RBCs in a unique protein complex that changes the affinity of TSPO ligands after Pf infection. TSPO ligands dose-dependently inhibited parasite growth, and this inhibition was correlated to ZnPPIX uptake and ROS accumulation in the infected RBCs. Our results demonstrate that TSPO ligands can induce Pf death by increasing the uptake of porphyrins through a TSPO2-VDAC complex, which leads to an accumulation of ROS.
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79
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Elustondo P, Martin LA, Karten B. Mitochondrial cholesterol import. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1862:90-101. [PMID: 27565112 DOI: 10.1016/j.bbalip.2016.08.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Revised: 08/15/2016] [Accepted: 08/19/2016] [Indexed: 02/06/2023]
Abstract
All animal subcellular membranes require cholesterol, which influences membrane fluidity and permeability, fission and fusion processes, and membrane protein function. The distribution of cholesterol among subcellular membranes is highly heterogeneous and the cholesterol content of each membrane must be carefully regulated. Compared to other subcellular membranes, mitochondrial membranes are cholesterol-poor, particularly the inner mitochondrial membrane (IMM). As a result, steroidogenesis can be controlled through the delivery of cholesterol to the IMM, where it is converted to pregnenolone. The low basal levels of cholesterol also make mitochondria sensitive to changes in cholesterol content, which can have a relatively large impact on the biophysical and functional characteristics of mitochondrial membranes. Increased mitochondrial cholesterol levels have been observed in diverse pathological conditions including cancer, steatohepatitis, Alzheimer disease and Niemann-Pick Type C1-deficiency, and are associated with increased oxidative stress, impaired oxidative phosphorylation, and changes in the susceptibility to apoptosis, among other alterations in mitochondrial function. Mitochondria are not included in the vesicular trafficking network; therefore, cholesterol transport to mitochondria is mostly achieved through the activity of lipid transfer proteins at membrane contact sites or by cytosolic, diffusible lipid transfer proteins. Here we will give an overview of the main mechanisms involved in mitochondrial cholesterol import, focusing on the steroidogenic acute regulatory protein StAR/STARD1 and other members of the StAR-related lipid transfer (START) domain protein family, and we will discuss how changes in mitochondrial cholesterol levels can arise and affect mitochondrial function. This article is part of a Special Issue entitled: Lipids of Mitochondria edited by Guenther Daum.
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Affiliation(s)
- Pia Elustondo
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Laura A Martin
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Barbara Karten
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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80
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Costa B, Da Pozzo E, Cavallini C, Taliani S, Da Settimo F, Martini C. Long Residence Time at the Neurosteroidogenic 18 kDa Translocator Protein Characterizes the Anxiolytic Ligand XBD173. ACS Chem Neurosci 2016; 7:1041-6. [PMID: 27385308 DOI: 10.1021/acschemneuro.6b00149] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Recent data have demonstrated a positive correlation between the residence time (RT) and neurosteroidogenic efficacy of a ligand at the translocator protein (TSPO), an attractive anxyolitic target. To explore the potential impact of RT on TSPO ligand anxiolytic activity, the RT and the steroidogenic activity of XBD173, a ligand exerting anxiolytic activity in humans, were retrospectively evaluated. To this aim, XBD173 association and dissociation rate constants were measured (1.23 × 10(7) M(-1) min(-1) and 0.0079 min(-1), respectively). XBD173 resulted to have a long RT (127 min) and to stimulate efficaciously neurosteroidogenesis, in terms of pregnenolone production. The present findings corroborate the importance of TSPO ligand RT to predict their effective neurosteroidogenic activity and promising anxiolytic action. These positive results prompted us to set up a fast and high-throughput kinetic method to improve the efficiency of RT-based TSPO drug-discovery process.
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Affiliation(s)
- Barbara Costa
- Department of Pharmacy, University of Pisa, via Bonanno, 6-56126 Pisa, Italy
| | - Eleonora Da Pozzo
- Department of Pharmacy, University of Pisa, via Bonanno, 6-56126 Pisa, Italy
| | - Chiara Cavallini
- 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
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81
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Tetrapyrroles as Endogenous TSPO Ligands in Eukaryotes and Prokaryotes: Comparisons with Synthetic Ligands. Int J Mol Sci 2016; 17:ijms17060880. [PMID: 27271616 PMCID: PMC4926414 DOI: 10.3390/ijms17060880] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 05/17/2016] [Accepted: 05/19/2016] [Indexed: 12/26/2022] Open
Abstract
The 18 kDa translocator protein (TSPO) is highly 0conserved in eukaryotes and prokaryotes. Since its discovery in 1977, numerous studies established the TSPO’s importance for life essential functions. For these studies, synthetic TSPO ligands typically are applied. Tetrapyrroles present endogenous ligands for the TSPO. Tetrapyrroles are also evolutionarily conserved and regulate multiple functions. TSPO and tetrapyrroles regulate each other. In animals TSPO-tetrapyrrole interactions range from effects on embryonic development to metabolism, programmed cell death, response to stress, injury and disease, and even to life span extension. In animals TSPOs are primarily located in mitochondria. In plants TSPOs are also present in plastids, the nuclear fraction, the endoplasmic reticulum, and Golgi stacks. This may contribute to translocation of tetrapyrrole intermediates across organelles’ membranes. As in animals, plant TSPO binds heme and protoporphyrin IX. TSPO-tetrapyrrole interactions in plants appear to relate to development as well as stress conditions, including salt tolerance, abscisic acid-induced stress, reactive oxygen species homeostasis, and finally cell death regulation. In bacteria, TSPO is important for switching from aerobic to anaerobic metabolism, including the regulation of photosynthesis. As in mitochondria, in bacteria TSPO is located in the outer membrane. TSPO-tetrapyrrole interactions may be part of the establishment of the bacterial-eukaryote relationships, i.e., mitochondrial-eukaryote and plastid-plant endosymbiotic relationships.
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82
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Li F, Liu J, Liu N, Kuhn LA, Garavito RM, Ferguson-Miller S. Translocator Protein 18 kDa (TSPO): An Old Protein with New Functions? Biochemistry 2016; 55:2821-31. [PMID: 27074410 DOI: 10.1021/acs.biochem.6b00142] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Translocator protein 18 kDa (TSPO) was previously known as the peripheral benzodiazepine receptor (PBR) in eukaryotes, where it is mainly localized to the mitochondrial outer membrane. Considerable evidence indicates that it plays regulatory roles in steroidogenesis and apoptosis and is involved in various human diseases, such as metastatic cancer, Alzheimer's and Parkinson's disease, inflammation, and anxiety disorders. Ligands of TSPO are widely used as diagnostic tools and treatment options, despite there being no clear understanding of the function of TSPO. An ortholog in the photosynthetic bacterium Rhodobacter was independently discovered as the tryptophan-rich sensory protein (TspO) and found to play a role in the response to changes in oxygen and light conditions that regulate photosynthesis and respiration. As part of this highly conserved protein family found in all three kingdoms, the rat TSPO is able to rescue the knockout phenotype in Rhodobacter, indicating functional as well as structural conservation. Recently, a major breakthrough in the field was achieved: the determination of atomic-resolution structures of TSPO from different species by several independent groups. This now allows us to reexamine the function of TSPO with a molecular perspective. In this review, we focus on recently determined structures of TSPO and their implications for potential functions of this ubiquitous multifaceted protein. We suggest that TSPO is an ancient bacterial receptor/stress sensor that has developed additional interactions, partners, and roles in its mitochondrial outer membrane environment in eukaryotes.
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Affiliation(s)
- Fei Li
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States
| | - Jian Liu
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States
| | - Nan Liu
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States.,Department of Computer Science and Engineering, Michigan State University , East Lansing, Michigan 48824-1319, United States.,Department of Chemistry, Michigan State University , East Lansing, Michigan 48824-1319, United States
| | - Leslie A Kuhn
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States.,Department of Computer Science and Engineering, Michigan State University , East Lansing, Michigan 48824-1319, United States
| | - R Michael Garavito
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States
| | - Shelagh Ferguson-Miller
- Department of Biochemistry and Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States
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83
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TSPO: kaleidoscopic 18-kDa amid biochemical pharmacology, control and targeting of mitochondria. Biochem J 2016; 473:107-21. [PMID: 26733718 DOI: 10.1042/bj20150899] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The 18-kDa translocator protein (TSPO) localizes in the outer mitochondrial membrane (OMM) of cells and is readily up-regulated under various pathological conditions such as cancer, inflammation, mechanical lesions and neurological diseases. Able to bind with high affinity synthetic and endogenous ligands, its core biochemical function resides in the translocation of cholesterol into the mitochondria influencing the subsequent steps of (neuro-)steroid synthesis and systemic endocrine regulation. Over the years, however, TSPO has also been linked to core cellular processes such as apoptosis and autophagy. It interacts and forms complexes with other mitochondrial proteins such as the voltage-dependent anion channel (VDAC) via which signalling and regulatory transduction of these core cellular events may be influenced. Despite nearly 40 years of study, the precise functional role of TSPO beyond cholesterol trafficking remains elusive even though the recent breakthroughs on its high-resolution crystal structure and contribution to quality-control signalling of mitochondria. All this along with a captivating pharmacological profile provides novel opportunities to investigate and understand the significance of this highly conserved protein as well as contribute the development of specific therapeutics as presented and discussed in the present review.
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84
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Guilarte TR, Loth MK, Guariglia SR. TSPO Finds NOX2 in Microglia for Redox Homeostasis. Trends Pharmacol Sci 2016; 37:334-343. [PMID: 27113160 DOI: 10.1016/j.tips.2016.02.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/22/2016] [Accepted: 02/25/2016] [Indexed: 10/21/2022]
Abstract
During the past decade, translocator protein 18 kDa (TSPO), previously named peripheral benzodiazepine receptor, has gained a great deal of attention based on its use as a clinical biomarker of neuroinflammation with therapeutic potential. However, there is a paucity of knowledge on the function(s) of TSPO in glial cells. Here, we identify a novel function of TSPO in microglia that is not associated with steroidogenesis. We propose that a TSPO interaction with NADPH oxidase (NOX2) links the generation of reactive oxygen species (ROS) to the induction of an antioxidant response to maintain redox homeostasis. This line of investigation may provide a greater understanding of TSPO glial cell biology, and the knowledge gained may prove beneficial in devising therapeutic strategies.
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Affiliation(s)
- Tomás R Guilarte
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA.
| | - Meredith K Loth
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
| | - Sara R Guariglia
- Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA
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85
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Santoro A, Mattace Raso G, Taliani S, Da Pozzo E, Simorini F, Costa B, Martini C, Laneri S, Sacchi A, Cosimelli B, Calignano A, Da Settimo F, Meli R. TSPO-ligands prevent oxidative damage and inflammatory response in C6 glioma cells by neurosteroid synthesis. Eur J Pharm Sci 2016; 88:124-31. [PMID: 27094781 DOI: 10.1016/j.ejps.2016.04.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/01/2016] [Accepted: 04/05/2016] [Indexed: 11/30/2022]
Abstract
Translocator protein 18kDa (TSPO) is predominantly located in the mitochondrial outer membrane, playing an important role in steroidogenesis, inflammation, cell survival and proliferation. Its expression in central nervous system, mainly in glial cells, has been found to be upregulated in neuropathology, and brain injury. In this study, we investigated the anti-oxidative and anti-inflammatory effects of a group of TSPO ligands from the N,N-dialkyl-2-phenylindol-3-ylglyoxylamide class (PIGAs), highlighting the involvement of neurosteroids in their pharmacological effects. To this aim we used a well-known in vitro model of neurosteroidogenesis: the astrocytic C6 glioma cell line, where TSPO expression and localization, as well as cell response to TSPO ligand treatment, have been established. All PIGAs reduced l-buthionine-(S,R)-sulfoximine (BSO)-driven cell cytotoxicity and lipid peroxidation. Moreover, an anti-inflammatory effect was observed due to the reduction of inducible nitric oxide synthase and cyclooxygenase-2 induction in LPS/IFNγ challenged cells. Both effects were blunted by aminoglutethimide (AMG), an inhibitor of pregnenolone synthesis, suggesting neurosteroids' involvement in PIGA protective mechanism. Finally, pregnenolone evaluation in PIGA exposed cells revealed an increase in its synthesis, which was prevented by AMG pre-treatment. These findings indicate that these TSPO ligands reduce oxidative stress and pro-inflammatory enzymes in glial cells through the de novo synthesis of neurosteroids, suggesting that these compounds could be potential new therapeutic tools for the treatment of inflammatory-based neuropathologies with beneficial effects possibly comparable to steroids, but potentially avoiding the negative side effects of long-term therapies with steroid hormones.
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Affiliation(s)
- Anna Santoro
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, University of Pisa, 56126 Pisa, Italy
| | - Giuseppina Mattace Raso
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, University of Pisa, 56126 Pisa, Italy
| | - Sabrina Taliani
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy
| | | | | | - Barbara Costa
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy
| | - Claudia Martini
- Department of Pharmacy, University of Pisa, 56126 Pisa, Italy
| | - Sonia Laneri
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, University of Pisa, 56126 Pisa, Italy
| | - Antonia Sacchi
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, University of Pisa, 56126 Pisa, Italy
| | - Barbara Cosimelli
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, University of Pisa, 56126 Pisa, Italy
| | - Antonio Calignano
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, University of Pisa, 56126 Pisa, Italy
| | | | - Rosaria Meli
- Department of Pharmacy, University of Naples Federico II, 80131 Naples, University of Pisa, 56126 Pisa, Italy.
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86
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Overexpression of PRL7D1 in Leydig Cells Causes Male Reproductive Dysfunction in Mice. Int J Mol Sci 2016; 17:ijms17010096. [PMID: 26771609 PMCID: PMC4730338 DOI: 10.3390/ijms17010096] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 01/03/2016] [Accepted: 01/06/2016] [Indexed: 01/02/2023] Open
Abstract
Prolactin family 7, subfamily d, member 1 (PRL7D1) is found in mouse placenta. Our recent work showed that PRL7D1 is also present in mouse testis Leydig cells, and the expression of PRL7D1 in the testis exhibits an age-related increase. In the present study, we generated transgenic mice with Leydig cell-specific PRL7D1 overexpression to explore its function during male reproduction. Prl7d1 male mice exhibited subfertility as reflected by reduced sperm counts and litter sizes. The testes from Prl7d1 transgenic mice appeared histologically normal, but the frequency of apoptotic germ cells was increased. Prl7d1 transgenic mice also had lower testosterone concentrations than wild-type mice. Mechanistic studies revealed that Prl7d1 transgenic mice have defects in the testicular expression of steroidogenic acute regulatory protein (STAR) and hydroxy-delta-5-steroid dehydrogenase, 3 beta- and steroid delta-isomerase cluster (HSD3B). Further studies revealed that PRL7D1 overexpression affected the expression of transferrin (TF) in Sertoli cells. These results suggest that PRL7D1 overexpression could lead to increased germ cell apoptosis and exert an inhibitory effect on testosterone production in Leydig cells by reducing the expression of certain steroidogenic-related genes. In addition, PRL7D1 appears to have important roles in the function of Sertoli cells, which, in turn, affects male fertility. We conclude that the expression level of PRL7D1 is associated with the reproductive function of male mice.
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87
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Costa B, Da Pozzo E, Giacomelli C, Barresi E, Taliani S, Da Settimo F, Martini C. TSPO ligand residence time: a new parameter to predict compound neurosteroidogenic efficacy. Sci Rep 2016; 6:18164. [PMID: 26750656 PMCID: PMC4707509 DOI: 10.1038/srep18164] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/13/2015] [Indexed: 12/19/2022] Open
Abstract
The pharmacological activation of the cholesterol-binding Translocator Protein (TSPO) leads to an increase of endogenous steroids and neurosteroids determining benefic pleiotropic effects in several pathological conditions, including anxiety disorders. The relatively poor relationship between TSPO ligand binding affinities and steroidogenic efficacies prompted us to investigate the time (Residence Time, RT) that a number of compounds with phenylindolylglyoxylamide structure (PIGAs) spends in contact with the target. Here, given the poor availability of TSPO ligand kinetic parameters, a kinetic radioligand binding assay was set up and validated for RT determination using a theoretical mathematical model successfully applied to other ligand-target systems. TSPO ligand RT was quantified and the obtained results showed a positive correlation between the period for which a drug interacts with TSPO and the compound ability to stimulate steroidogenesis. Specifically, the TSPO ligand RT significantly fitted both with steroidogenic efficacy (Emax) and with area under the dose-response curve, a parameter combining drug potency and efficacy. A positive relation between RT and anxiolytic activity of three compounds was evidenced. In conclusion, RT could be a relevant parameter to predict the steroidogenic efficacy and the in vivo anxiolytic action of new TSPO ligands.
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Affiliation(s)
- Barbara Costa
- Department of Pharmacy, University of Pisa, via Bonanno, 6-56126 Pisa, Italy
| | - Eleonora Da Pozzo
- Department of Pharmacy, University of Pisa, via Bonanno, 6-56126 Pisa, Italy
| | - Chiara Giacomelli
- Department of Pharmacy, University of Pisa, via Bonanno, 6-56126 Pisa, Italy
| | - Elisabetta Barresi
- 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
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88
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Morin D, Musman J, Pons S, Berdeaux A, Ghaleh B. Mitochondrial translocator protein (TSPO): From physiology to cardioprotection. Biochem Pharmacol 2015; 105:1-13. [PMID: 26688086 DOI: 10.1016/j.bcp.2015.12.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/04/2015] [Indexed: 01/08/2023]
Abstract
The mitochondrial translocator protein (TSPO) is a high affinity cholesterol binding protein which is primarily located in the outer mitochondrial membrane where it has been shown to interact with proteins implicated in mitochondrial permeability transition pore (mPTP) formation. TSPO is found in different species and is expressed at high levels in tissues that synthesize steroids but is also present in other peripheral tissues especially in the heart. TSPO has been involved in the import of cholesterol into mitochondria, a key step in steroidogenesis. This constitutes the main established function of the protein which was recently challenged by genetic studies. TSPO has also been associated directly or indirectly with a wide range of cellular functions such as apoptosis, cell proliferation, differentiation, regulation of mitochondrial function or porphyrin transport. In the heart the role of TSPO remains undefined but a growing body of evidence suggests that TSPO plays a critical role in regulating physiological cardiac function and that TSPO ligands may represent interesting drugs to protect the heart under pathological conditions. This article briefly reviews current knowledge regarding TSPO and discusses its role in the cardiovascular system under physiological and pathologic conditions. More particularly, it provides evidence that TSPO can represent an alternative strategy to develop new pharmacological agents to protect the myocardium against ischemia-reperfusion injury.
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Affiliation(s)
- Didier Morin
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
| | - Julien Musman
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
| | - Sandrine Pons
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
| | - Alain Berdeaux
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
| | - Bijan Ghaleh
- INSERM U955, Équipe 3, Créteil, France; Université Paris-Est, UMR_S955, DHU A-TVB, UPEC, Créteil, France.
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90
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Schumacher M, Guennoun R, Mattern C, Oudinet JP, Labombarda F, De Nicola AF, Liere P. Analytical challenges for measuring steroid responses to stress, neurodegeneration and injury in the central nervous system. Steroids 2015; 103:42-57. [PMID: 26301525 DOI: 10.1016/j.steroids.2015.08.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 08/17/2015] [Accepted: 08/19/2015] [Indexed: 12/22/2022]
Abstract
Levels of steroids in the adult central nervous system (CNS) show marked changes in response to stress, degenerative disorders and injury. However, their analysis in complex matrices such as fatty brain and spinal cord tissues, and even in plasma, requires accurate and precise analytical methods. Radioimmunoassays (RIA) and enzyme-linked immunosorbent assays, even with prepurification steps, do not provide sufficient specificity, and they are at the origin of many inconsistent results in the literature. The analysis of steroids by mass spectrometric methods has become the gold standard for accurate and sensitive steroid analysis. However, these technologies involve multiple purification steps prone to errors, and they only provide accurate reference values when combined with careful sample workup. In addition, the interpretation of changes in CNS steroid levels is not an easy task because of their multiple sources: the endocrine glands and the local synthesis by neural cells. In the CNS, decreased steroid levels may reflect alterations of their biosynthesis, as observed in the case of chronic stress, post-traumatic stress disorders or depressive episodes. In such cases, return to normalization by administering exogenous hormones or by stimulating their endogenous production may have beneficial effects. On the other hand, increases in CNS steroids in response to acute stress, degenerative processes or injury may be part of endogenous protective or rescue programs, contributing to the resistance of neural cells to stress and insults. The aim of this review is to encourage a more critical reading of the literature reporting steroid measures, and to draw attention to the absolute need for well-validated methods. We discuss reported findings concerning changing steroid levels in the nervous system by insisting on methodological issues. An important message is that even recent mass spectrometric methods have their limits, and they only become reliable tools if combined with careful sample preparation.
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Affiliation(s)
| | | | | | | | - Florencia Labombarda
- Instituto de Biologia y Medicina Experimental and University of Buenos Aires, Argentina
| | - Alejandro F De Nicola
- Instituto de Biologia y Medicina Experimental and University of Buenos Aires, Argentina
| | - Philippe Liere
- U1195 Inserm and University Paris-Sud, Kremlin-Bicêtre, France
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91
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Arbo BD, Benetti F, Garcia-Segura LM, Ribeiro MF. Therapeutic actions of translocator protein (18 kDa) ligands in experimental models of psychiatric disorders and neurodegenerative diseases. J Steroid Biochem Mol Biol 2015. [PMID: 26200949 DOI: 10.1016/j.jsbmb.2015.07.007] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Translocator protein (TSPO) is an 18kDa protein located at contact sites between the outer and the inner mitochondrial membrane. Numerous studies have associated TSPO with the translocation of cholesterol across the aqueous mitochondrial intermembrane space and the regulation of steroidogenesis, as well as with the control of some other mitochondrial functions, such as mitochondrial respiration, mitochondrial permeability transition pore opening, apoptosis and cell proliferation. In the brain, changes in TSPO expression occur in several neuropathological conditions including neurodegenerative diseases and psychiatric disorders. Furthermore, TSPO ligands have been shown to promote neuroprotection in animal models of brain pathology. At least in some cases, the mechanisms of neuroprotection are associated with modifications in brain steroidogenesis. In addition, regulation of neuroinflammation seems to be a common mechanism in the neuroprotective actions of TSPO ligands in different animal models of brain pathology.
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Affiliation(s)
- B D Arbo
- Laboratório de Interação Neuro-Humoral, Department of Physiology, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Sarmento Leite, 500, CEP 90050-170 Porto Alegre, RS, Brazil; Cajal Institute, CSIC, Avenida Doctor Arce, 37, 28002 Madrid, Spain.
| | - F Benetti
- Laboratório de Neurofisiologia Cognitiva e do Desenvolvimento, Department of Physiology, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Sarmento Leite, 500, CEP 90050-170 Porto Alegre, RS, Brazil
| | | | - M F Ribeiro
- Laboratório de Interação Neuro-Humoral, Department of Physiology, ICBS, Universidade Federal do Rio Grande do Sul (UFRGS), Rua Sarmento Leite, 500, CEP 90050-170 Porto Alegre, RS, Brazil
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Leneveu-Jenvrin C, Bouffartigues E, Maillot O, Cornelis P, Feuilloley MGJ, Connil N, Chevalier S. Expression of the translocator protein (TSPO) from Pseudomonas fluorescens Pf0-1 requires the stress regulatory sigma factors AlgU and RpoH. Front Microbiol 2015; 6:1023. [PMID: 26441945 PMCID: PMC4585239 DOI: 10.3389/fmicb.2015.01023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 09/08/2015] [Indexed: 11/19/2022] Open
Abstract
The translocator protein (TSPO), previously designated as peripheral-type benzodiazepine receptor, is an evolutionary conserved protein that is found in many Eukarya, Archae, and Bacteria, in which it plays several important functions including for example membrane biogenesis, signaling, and stress response. A tspo homolog gene has been identified in several members of the Pseudomonas genus, among which the soil bacterium P. fluorescens Pf0-1. In this bacterium, the tspo gene is located in the vicinity of a putative hybrid histidine kinase-encoding gene. Since tspo has been involved in water stress related response in plants, we explored the effects of hyperosmolarity and temperature on P. fluorescens Pf0-1 tspo expression using a strategy based on lux-reporter fusions. We show that the two genes Pfl01_2810 and tspo are co-transcribed forming a transcription unit. The expression of this operon is growth phase-dependent and is increased in response to high concentrations of NaCl, sucrose and to a D-cycloserine treatment, which are conditions leading to activity of the major cell wall stress responsive extracytoplasmic sigma factor AlgU. Interestingly, the promoter region activity is strongly lowered in a P. aeruginosa algU mutant, suggesting that AlgU may be involved at least partly in the molecular mechanism leading to Pfl01_2810-tspo expression. In silico analysis of this promoter region failed to detect an AlgU consensus binding site; however, a putative binding site for the heat shock response RpoH sigma factor was detected. Accordingly, the promoter activity of the region containing this sequence is increased in response to high growth temperature and slightly lowered in a P. aeruginosa rpoH mutant strain. Taken together, our data suggest that P. fluorescens tspo gene may belong at least partly to the cell wall stress response.
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Affiliation(s)
| | - Emeline Bouffartigues
- Laboratory of Microbiology Signals and Microenvironment, University of Rouen Evreux, France
| | - Olivier Maillot
- Laboratory of Microbiology Signals and Microenvironment, University of Rouen Evreux, France
| | - Pierre Cornelis
- Laboratory of Microbiology Signals and Microenvironment, University of Rouen Evreux, France
| | - Marc G J Feuilloley
- Laboratory of Microbiology Signals and Microenvironment, University of Rouen Evreux, France
| | - Nathalie Connil
- Laboratory of Microbiology Signals and Microenvironment, University of Rouen Evreux, France
| | - Sylvie Chevalier
- Laboratory of Microbiology Signals and Microenvironment, University of Rouen Evreux, France
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93
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Abstract
The translocator protein (TSPO; 18k Da) is an evolutionarily conserved outer mitochondrial membrane (OMM) protein highly expressed in steroid-synthesizing cells and found to possess a number of physiological and drug-binding partners. Extensive pharmacological, biochemical and cell biological research over the years has led to a model of TSPO involvement in mitochondrial cholesterol transport and promotion of steroid synthesis, a model guiding the design of drugs useful in stimulating neurosteroid synthesis and alleviating psychopathological symptoms. The involvement of TSPO in these processes has been called into question; however, with the publication of TSPO-deletion mouse models which saw no changes in steroid production. Here, we review work characterizing TSPO in steroidogenesis and offer perspective to research into TSPO pharmacology and its involvement in steroid biosynthesis.
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