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A Proteomic Platform Unveils the Brain Glycogen Phosphorylase as a Potential Therapeutic Target for Glioblastoma Multiforme. Int J Mol Sci 2022; 23:ijms23158200. [PMID: 35897773 PMCID: PMC9331883 DOI: 10.3390/ijms23158200] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 11/22/2022] Open
Abstract
In the last few years, several efforts have been made to identify original strategies against glioblastoma multiforme (GBM): this requires a more detailed investigation of the molecular mechanism of GBM so that novel targets can be identified for new possible therapeutic agents. Here, using a combined biochemical and proteomic approach, we evaluated the ability of a blood–brain barrier-permeable 2,3-benzodiazepin-4-one, called 1g, to interfere with the activity and the expression of brain glycogen phosphorylase (PYGB) on U87MG cell line in parallel with the capability of this compound to inhibit the cell growth and cycle. Thus, our results highlighted PYGB as a potential therapeutic target in GBM prompting 1g as a capable anticancer drug thanks to its ability to negatively modulate the uptake and metabolism of glucose, the so-called “Warburg effect”, whose increase is considered a common feature of cancer cells in respect of their normal counterparts.
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2
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Juhász T, Quemé-Peña M, Kővágó B, Mihály J, Ricci M, Horváti K, Bősze S, Zsila F, Beke-Somfai T. Interplay between membrane active host defense peptides and heme modulates their assemblies and in vitro activity. Sci Rep 2021; 11:18328. [PMID: 34526616 PMCID: PMC8443738 DOI: 10.1038/s41598-021-97779-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/28/2021] [Indexed: 02/08/2023] Open
Abstract
In the emerging era of antimicrobial resistance, the susceptibility to co-infections of patients suffering from either acquired or inherited hemolytic disorders can lead to dramatic increase in mortality rates. Closely related, heme liberated during hemolysis is one of the major sources of iron, which is vital for both host and invading microorganisms. While recent intensive research in the field has demonstrated that heme exerts diverse local effects including impairment of immune cells functions, it is almost completely unknown how it may compromise key molecules of our innate immune system, such as antimicrobial host defense peptides (HDPs). Since HDPs hold great promise as natural therapeutic agents against antibiotic-resistant microbes, understanding the effects that may modulate their action in microbial infection is crucial. Here we explore how hemin can interact directly with selected HDPs and influence their structure and membrane activity. It is revealed that induced helical folding, large assembly formation, and altered membrane activity is promoted by hemin. However, these effects showed variations depending mainly on peptide selectivity toward charged lipids, and the affinity of the peptide and hemin to lipid bilayers. Hemin-peptide complexes are sought to form semi-folded co-assemblies, which are present even with model membranes resembling mammalian or bacterial lipid compositions. In vitro cell-based toxicity assays supported that toxic effects of HDPs could be attenuated due to their assembly formation. These results are in line with our previous findings on peptide-lipid-small molecule systems suggesting that small molecules present in the complex in vivo milieu can regulate HDP function. Inversely, diverse effects of endogenous compounds could also be manipulated by HDPs.
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Affiliation(s)
- Tünde Juhász
- grid.425578.90000 0004 0512 3755Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Mayra Quemé-Peña
- grid.425578.90000 0004 0512 3755Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest, Hungary ,grid.5591.80000 0001 2294 6276Hevesy György PhD School of Chemistry, Eötvös Loránd University, Budapest, Hungary
| | - Bence Kővágó
- grid.425578.90000 0004 0512 3755Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Judith Mihály
- grid.425578.90000 0004 0512 3755Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Maria Ricci
- grid.425578.90000 0004 0512 3755Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Kata Horváti
- grid.5591.80000 0001 2294 6276ELKH-ELTE Research Group of Peptide Chemistry, Eötvös Loránd University, Budapest, Hungary ,grid.5591.80000 0001 2294 6276Department of Organic Chemistry, Eötvös Loránd University, Budapest, Hungary
| | - Szilvia Bősze
- grid.5591.80000 0001 2294 6276ELKH-ELTE Research Group of Peptide Chemistry, Eötvös Loránd University, Budapest, Hungary
| | - Ferenc Zsila
- grid.425578.90000 0004 0512 3755Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
| | - Tamás Beke-Somfai
- grid.425578.90000 0004 0512 3755Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Budapest, Hungary
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3
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Loke YL, Chew MT, Ngeow YF, Lim WWD, Peh SC. Colon Carcinogenesis: The Interplay Between Diet and Gut Microbiota. Front Cell Infect Microbiol 2020; 10:603086. [PMID: 33364203 PMCID: PMC7753026 DOI: 10.3389/fcimb.2020.603086] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/28/2020] [Indexed: 12/24/2022] Open
Abstract
Colorectal cancer (CRC) incidence increases yearly, and is three to four times higher in developed countries compared to developing countries. The well-known risk factors have been attributed to low physical activity, overweight, obesity, dietary consumption including excessive consumption of red processed meats, alcohol, and low dietary fiber content. There is growing evidence of the interplay between diet and gut microbiota in CRC carcinogenesis. Although there appears to be a direct causal role for gut microbes in the development of CRC in some animal models, the link between diet, gut microbes, and colonic carcinogenesis has been established largely as an association rather than as a cause-and-effect relationship. This is especially true for human studies. As essential dietary factors influence CRC risk, the role of proteins, carbohydrates, fat, and their end products are considered as part of the interplay between diet and gut microbiota. The underlying molecular mechanisms of colon carcinogenesis mediated by gut microbiota are also discussed. Human biological responses such as inflammation, oxidative stress, deoxyribonucleic acid (DNA) damage can all influence dysbiosis and consequently CRC carcinogenesis. Dysbiosis could add to CRC risk by shifting the effect of dietary components toward promoting a colonic neoplasm together with interacting with gut microbiota. It follows that dietary intervention and gut microbiota modulation may play a vital role in reducing CRC risk.
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Affiliation(s)
- Yean Leng Loke
- Centre for Biomedical Physics, School of Healthcare and Medical Sciences, Sunway University, Petaling Jaya, Malaysia
| | - Ming Tsuey Chew
- Centre for Biomedical Physics, School of Healthcare and Medical Sciences, Sunway University, Petaling Jaya, Malaysia
| | - Yun Fong Ngeow
- Faculty of Medicine and Health Sciences, Universiti Tunku Abdul Rahman, Kajang, Malaysia.,Centre for Research on Communicable Diseases, Universiti Tunku Abdul Rahman, Kajang, Malaysia
| | - Wendy Wan Dee Lim
- Department of Gastroenterology, Sunway Medical Centre, Petaling Jaya, Malaysia
| | - Suat Cheng Peh
- Ageing Health and Well-Being Research Centre, Sunway University, Petaling Jaya, Malaysia.,Department of Medical Sciences, School of Healthcare and Medical Sciences, Sunway University, Petaling Jaya, Malaysia
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4
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Yagensky O, Kohansal-Nodehi M, Gunaseelan S, Rabe T, Zafar S, Zerr I, Härtig W, Urlaub H, Chua JJ. Increased expression of heme-binding protein 1 early in Alzheimer's disease is linked to neurotoxicity. eLife 2019; 8:47498. [PMID: 31453805 PMCID: PMC6739868 DOI: 10.7554/elife.47498] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/25/2019] [Indexed: 12/15/2022] Open
Abstract
Alzheimer’s disease is the most prevalent neurodegenerative disorder leading to progressive cognitive decline. Despite decades of research, understanding AD progression at the molecular level, especially at its early stages, remains elusive. Here, we identified several presymptomatic AD markers by investigating brain proteome changes over the course of neurodegeneration in a transgenic mouse model of AD (3×Tg-AD). We show that one of these markers, heme-binding protein 1 (Hebp1), is elevated in the brains of both 3×Tg-AD mice and patients affected by rapidly-progressing forms of AD. Hebp1, predominantly expressed in neurons, interacts with the mitochondrial contact site complex (MICOS) and exhibits a perimitochondrial localization. Strikingly, wildtype, but not Hebp1-deficient, neurons showed elevated cytotoxicity in response to heme-induced apoptosis. Increased survivability in Hebp1-deficient neurons is conferred by blocking the activation of the mitochondrial-associated caspase signaling pathway. Taken together, our data highlight a role of Hebp1 in progressive neuronal loss during AD progression.
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Affiliation(s)
- Oleksandr Yagensky
- Research Group Protein Trafficking in Synaptic Development and Function, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | | | - Saravanan Gunaseelan
- Interactomics and Intracellular Trafficking Laboratory, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Tamara Rabe
- Department of Genes and Behavior, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Saima Zafar
- Biomedical Engineering and Sciences Department, School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Islamabad, Pakistan.,Clinical Dementia Center, Department of Neurology, German Center for Neurodegenerative Diseases, University Medical Center Göttingen, Göttingen, Germany
| | - Inga Zerr
- Clinical Dementia Center, Department of Neurology, German Center for Neurodegenerative Diseases, University Medical Center Göttingen, Göttingen, Germany
| | - Wolfgang Härtig
- Paul Flechsig Institute for Brain Research, University of Leipzig, Leipzig, Germany
| | - Henning Urlaub
- Research Group Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Bioanalytics Group, Institute for Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - John Je Chua
- Research Group Protein Trafficking in Synaptic Development and Function, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.,Interactomics and Intracellular Trafficking Laboratory, Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,LSI Neurobiology Programme, National University of Singapore, Singapore, Singapore.,Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.,Institute for Health Innovation and Technology, National University of Singapore, Singapore, Singapore
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5
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Hemin-induced platelet activation and ferroptosis is mediated through ROS-driven proteasomal activity and inflammasome activation: Protection by Melatonin. Biochim Biophys Acta Mol Basis Dis 2019; 1865:2303-2316. [PMID: 31102787 DOI: 10.1016/j.bbadis.2019.05.009] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 01/08/2023]
Abstract
Reactive oxygen species (ROS) are capable of inducing cell death or apoptosis. Recently, we demonstrated that lipid-ROS can mediate ferroptosis and activation of human platelets. Ferroptosis is an intracellular iron-mediated cell death, distinct from classical apoptosis and necrosis, which is mediated through the accumulation of ROS, lipid peroxides and depletion of cellular GSH. Lately, we demonstrated that hemoglobin degradation product hemin induces ferroptosis in platelets via ROS and lipid peroxidation. In this study, we demonstrate that hemin-induced ferroptosis in platelets is mediated through ROS-driven proteasome activity and inflammasome activation, which were mitigated by Melatonin (MLT). Although inflammasome activation is linked with pyroptosis, it is still not clear whether ferroptosis is associated with inflammasome activation. Our study for the first time demonstrates an association of platelet activation/ferroptosis with proteasome activity and inflammasome activation. Although, high-throughput screening has recognized ferrostatin-1 (Fer-1) and liproxstatin-1 (Lip-1) as potent ferroptosis inhibitors, having an endogenous antioxidant such as MLT as ferroptosis inhibitor is of high interest. MLT is a well-known chronobiotic hormone that regulates the circadian rhythms in vertebrates. It also exhibits potent antioxidant and ROS quenching capabilities. MLT can regulate fundamental cellular functions by exhibiting cytoprotective, oncostatic, antiaging, anti-venom, and immunomodulatory activities. The ROS scavenging capacity of MLT is key for its cytoprotective and anti-apoptotic properties. Considering the anti-ferroptotic and anti-apoptotic potentials of MLT, it could be a promising clinical application to treat hemolytic, thrombotic and thrombocytopenic conditions. Therefore, we propose MLT as a pharmacological and therapeutic agent to inhibit ferroptosis and platelet activation.
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6
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Kim H, Yin K, Falcon DM, Xue X. The interaction of Hemin and Sestrin2 modulates oxidative stress and colon tumor growth. Toxicol Appl Pharmacol 2019; 374:77-85. [PMID: 31054940 DOI: 10.1016/j.taap.2019.04.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/25/2019] [Accepted: 04/30/2019] [Indexed: 01/01/2023]
Abstract
Several large epidemiological and animal studies demonstrate a direct correlation between dietary heme iron intake and/or systemic iron levels and cancer risk in several cancers including colorectal cancer (CRC). However, the precise mechanisms for how heme iron contributes to CRC and how cancer cells respond to heme iron-induced stress are still unclear. Previously we have shown that one of the stress-inducible proteins, Sestrin2 (SESN2), is a novel tumor suppressor in colon by limiting endoplasmic reticulum stress and mammalian target of rapamycin complex 1 (mTORC1) signaling and tumor growth. But the relationship between heme iron and SESN2, especially in the context of colon carcinogenesis, was not investigated previously. Here, we found that hemin dose-dependently increased SESN2 expression in an oxidative stress and nuclear factor (erythroid-derived 2)-like 2 (NFE2L2, NRF2)-dependent manner. Since SESN2 overexpression reduced hemin-induced oxidative stress, SESN2 could be an important target of NRF2 exerting antioxidant function. Indeed, expression of several oxidative stress responsive proteins such as NRF2 and its target genes was reduced by SESN2. Although we formerly reported that SESN2 expression was reduced after p53 mutation in colon tumors, mouse colon tumors, which have intact p53 and NRF2, induced SESN2 expression in response to iron stimulus. Although SESN2 overexpression decreased murine colon tumor cell growth both in vitro and in vivo, it rendered colon cancer cells more resistant to hemin-induced apoptosis and therefore promoted tumor growth during hemin treatment. Taken together, although SESN2 generally suppresses tumorigenesis, it can produce tumor-promoting role in iron-rich environment by suppressing oxidative stress-associated cancer cell death.
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Affiliation(s)
- Hyeoncheol Kim
- Department of Biochemistry and Molecular Biology, University of New Mexico, Albuquerque, NM 87131, United States of America
| | - Kunlun Yin
- Department of Biochemistry and Molecular Biology, University of New Mexico, Albuquerque, NM 87131, United States of America
| | - Daniel M Falcon
- Department of Biochemistry and Molecular Biology, University of New Mexico, Albuquerque, NM 87131, United States of America
| | - Xiang Xue
- Department of Biochemistry and Molecular Biology, University of New Mexico, Albuquerque, NM 87131, United States of America.
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7
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Gyongyosi A, Szoke K, Fenyvesi F, Fejes Z, Debreceni IB, Nagy B, Tosaki A, Lekli I. Inhibited autophagy may contribute to heme toxicity in cardiomyoblast cells. Biochem Biophys Res Commun 2019; 511:732-738. [DOI: 10.1016/j.bbrc.2019.02.140] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 02/25/2019] [Indexed: 10/27/2022]
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8
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Upregulation of Heme Oxygenase-1 by Hemin Alleviates Sepsis-Induced Muscle Wasting in Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8927104. [PMID: 30533176 PMCID: PMC6250022 DOI: 10.1155/2018/8927104] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 09/13/2018] [Accepted: 10/04/2018] [Indexed: 11/18/2022]
Abstract
Hemin, an inducer of heme oxygenase-1 (HO-1), can enhance the activation of HO-1. HO-1 exhibits a variety of activities, such as anti-inflammatory, antioxidative, and antiapoptotic functions. The objective of this study was to investigate the effects of hemin on sepsis-induced skeletal muscle wasting and to explore the mechanisms by which hemin exerts its effects. Cecal ligation and perforation (CLP) was performed to create a sepsis mouse model. Mice were randomly divided into four groups: control, CLP, CLP plus group, and CLP-hemin-ZnPP (a HO-1 inhibitor). The weight of the solei from the mice was measured, and histopathology was examined. Cytokines were measured by enzyme-linked immunosorbent assay (ELISA). Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blotting were used to assess the expression levels of HO-1 and atrogin-1. Furthermore, we investigated the antioxidative effects of HO-1 by detecting malondialdehyde (MDA) levels and superoxide dismutase (SOD) activity. CLP led to dramatic skeletal muscle weakness and atrophy, but pretreatment with hemin protected mice against CLP-mediated muscle atrophy. Hemin also induced high HO-1 expression, which resulted in suppressed proinflammatory cytokine and reactive oxygen species (ROS) production. The expression of MuRF1 and atrogin-1, two ubiquitin ligases of the ubiquitin-proteasome system- (UPS-) mediated proteolysis, was also inhibited by increased HO-1 levels. Hemin-mediated increases in HO-1 expression exert protective effects on sepsis-induced skeletal muscle atrophy at least partly by inhibiting the expression of proinflammatory cytokines, UPS-mediated proteolysis, and ROS activation. Therefore, hemin might be a new treatment target against sepsis-induced skeletal muscle atrophy.
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9
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Giri RP, Mukhopadhyay MK, Basak UK, Chakrabarti A, Sanyal MK, Runge B, Murphy BM. Continuous Uptake or Saturation—Investigation of Concentration and Surface-Packing-Specific Hemin Interaction with Lipid Membranes. J Phys Chem B 2018; 122:7547-7554. [DOI: 10.1021/acs.jpcb.8b03327] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- R. P. Giri
- Saha Institute of Nuclear Physics, HBNI, 1/AF Bidhannagar, Kolkata 700064, India
| | - M. K. Mukhopadhyay
- Saha Institute of Nuclear Physics, HBNI, 1/AF Bidhannagar, Kolkata 700064, India
| | - U. K. Basak
- Saha Institute of Nuclear Physics, HBNI, 1/AF Bidhannagar, Kolkata 700064, India
| | - A. Chakrabarti
- Saha Institute of Nuclear Physics, HBNI, 1/AF Bidhannagar, Kolkata 700064, India
| | - M. K. Sanyal
- Saha Institute of Nuclear Physics, HBNI, 1/AF Bidhannagar, Kolkata 700064, India
| | - B. Runge
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
| | - B. M. Murphy
- Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
- Ruprecht Haensel Laboratory, Christian-Albrechts-Universität zu Kiel, 24098 Kiel, Germany
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10
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Bonsack F, Sukumari-Ramesh S. TSPO: An Evolutionarily Conserved Protein with Elusive Functions. Int J Mol Sci 2018; 19:ijms19061694. [PMID: 29875327 PMCID: PMC6032217 DOI: 10.3390/ijms19061694] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 05/18/2018] [Indexed: 12/22/2022] Open
Abstract
TSPO (18 kDa translocator protein) was identified decades ago in a search for peripheral tissue binding sites for benzodiazepines, and was formerly called the peripheral benzodiazepine receptor. TSPO is a conserved protein throughout evolution and it is implicated in the regulation of many cellular processes, including inflammatory responses, oxidative stress, and mitochondrial homeostasis. TSPO, apart from its broad expression in peripheral tissues, is highly expressed in neuroinflammatory cells, such as activated microglia. In addition, emerging studies employing the ligands of TSPO suggest that TSPO plays an important role in neuropathological settings as a biomarker and therapeutic target. However, the precise molecular function of this protein in normal physiology and neuropathology remains enigmatic. This review provides an overview of recent advances in our understanding of this multifaceted molecule and identifies the knowledge gap in the field for future functional studies.
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Affiliation(s)
- Frederick Bonsack
- Department of Neurosurgery, Medical College of Georgia, Augusta University, 1120 15th Street, Augusta, GA 30912, USA.
| | - Sangeetha Sukumari-Ramesh
- Department of Neurosurgery, Medical College of Georgia, Augusta University, 1120 15th Street, Augusta, GA 30912, USA.
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11
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Cornejo-Corona I, Thapa HR, Browne DR, Devarenne TP, Lozoya-Gloria E. Stress responses of the oil-producing green microalga Botryococcus braunii Race B. PeerJ 2016; 4:e2748. [PMID: 27957393 PMCID: PMC5144741 DOI: 10.7717/peerj.2748] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/03/2016] [Indexed: 11/20/2022] Open
Abstract
Plants react to biotic and abiotic stresses with a variety of responses including the production of reactive oxygen species (ROS), which may result in programmed cell death (PCD). The mechanisms underlying ROS production and PCD have not been well studied in microalgae. Here, we analyzed ROS accumulation, biomass accumulation, and hydrocarbon production in the colony-forming green microalga Botryococcus braunii in response to several stress inducers such as NaCl, NaHCO3, salicylic acid (SA), methyl jasmonate, and acetic acid. We also identified and cloned a single cDNA for the B. braunii ortholog of the Arabidopsis gene defender against cell death 1 (DAD1), a gene that is directly involved in PCD regulation. The function of B. braunii DAD1 was assessed by a complementation assay of the yeast knockout line of the DAD1 ortholog, oligosaccharyl transferase 2. Additionally, we found that DAD1 transcription was induced in response to SA at short times. These results suggest that B. braunii responds to stresses by mechanisms similar to those in land plants and other organisms.
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Affiliation(s)
- Ivette Cornejo-Corona
- Genetic Engineering, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Irapuato , Irapuato , Guanajuato , Mexico
| | - Hem R Thapa
- Department of Biochemistry and Biophysics, Texas A&M University , College Station , TX , United States
| | - Daniel R Browne
- Department of Biochemistry and Biophysics, Texas A&M University , College Station , TX , United States
| | - Timothy P Devarenne
- Department of Biochemistry and Biophysics, Texas A&M University , College Station , TX , United States
| | - Edmundo Lozoya-Gloria
- Genetic Engineering, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Unidad Irapuato , Irapuato , Guanajuato , Mexico
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12
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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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Abstract
The mitochondrial 18-kDa translocator protein (TSPO) was originally discovered as a peripheral binding site of benzodiazepines to be later described as a core element of cholesterol trafficking between cytosol and mitochondria from which the current nomenclature originated. The high affinity it exhibits with chemicals (i.e. PK11195) has generated interest in the development of mitochondrial based TSPO-binding drugs for in vitro and in vivo analysis. Increased TSPO expression is observed in numerous pathologies such as cancer and inflammatory conditions of the central nervous system (CNS) that have been successfully exploited via protocols of positron emission tomography (PET) imaging. We endeavoured to dissect the molecular role of TSPO in mitochondrial cell biology and discovered a functional link with quality control mechanisms operated by selective autophagy. This review focuses on the current understanding of this pathway and focuses on the interplay with reactive oxygen species (ROS) and the voltage-dependent anion channel (VDAC), to which TSPO binds, in the regulation of cell mitophagy and hence homoeostasis of the mitochondrial network as a whole.
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Selvaraj V, Stocco DM. The changing landscape in translocator protein (TSPO) function. Trends Endocrinol Metab 2015; 26:341-8. [PMID: 25801473 PMCID: PMC7171652 DOI: 10.1016/j.tem.2015.02.007] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 02/11/2015] [Accepted: 02/18/2015] [Indexed: 11/25/2022]
Abstract
Translocator protein (TSPO), previously known as the peripheral benzodiazepine receptor (PBR), is an outer mitochondrial membrane protein. TSPO has been shown to cooperate with steroidogenic acute regulatory protein (StAR) and function in the transport of cholesterol into mitochondria. TSPO has also been considered as a structural component of the mitochondrial permeability transition pore (MPTP). However, recent advances have changed these views of TSPO's functions and have prompted a re-evaluation of established concepts. This review summarizes the history of TSPO, key elements of the debate, and functional experiments that have changed our understanding. Moving forward, we examine how this fundamental change impacts our understanding of TSPO and affects the future of TSPO as a therapeutic and diagnostic target.
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Affiliation(s)
- Vimal Selvaraj
- Department of Animal Science, Cornell University, Ithaca, NY 14853, USA.
| | - Douglas M Stocco
- Department of Cell Biology and Biochemistry, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
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