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Moras M, Hattab C, Gonzalez-Menendez P, Martino S, Larghero J, Le Van Kim C, Kinet S, Taylor N, Lefevre SD, Ostuni MA. Downregulation of Mitochondrial TSPO Inhibits Mitophagy and Reduces Enucleation during Human Terminal Erythropoiesis. Int J Mol Sci 2020; 21:ijms21239066. [PMID: 33260618 PMCID: PMC7730461 DOI: 10.3390/ijms21239066] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 12/13/2022] Open
Abstract
Translocator protein (TSPO) and voltage dependent anion channels (VDAC) are two proteins forming a macromolecular complex in the outer mitochondrial membrane that is involved in pleiotropic functions. Specifically, these proteins were described to regulate the clearance of damaged mitochondria by selective mitophagy in non-erythroid immortalized cell lines. Although it is well established that erythroblast maturation in mammals depends on organelle clearance, less is known about mechanisms regulating this clearance throughout terminal erythropoiesis. Here, we studied the effect of TSPO1 downregulation and the action of Ro5-4864, a drug ligand known to bind to the TSPO/VDAC complex interface, in ex vivo human terminal erythropoiesis. We found that both treatments delay mitochondrial clearance, a process associated with reduced levels of the PINK1 protein, which is a key protein triggering canonical mitophagy. We also observed that TSPO1 downregulation blocks erythroblast maturation at the orthochromatic stage, decreases the enucleation rate, and increases cell death. Interestingly, TSPO1 downregulation does not modify reactive oxygen species (ROS) production nor intracellular adenosine triphosphate (ATP) levels. Ro5-4864 treatment recapitulates these phenotypes, strongly suggesting an active role of the TSPO/VDAC complex in selective mitophagy throughout human erythropoiesis. The present study links the function of the TSPO/VDAC complex to the PINK1/Parkin-dependent mitophagy induction during terminal erythropoiesis, leading to the proper completion of erythroid maturation.
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Affiliation(s)
- Martina Moras
- Inserm, BIGR, UMR_S1134, Université de Paris, F-75015 Paris, France; (M.M.); (C.H.); (S.M.); (C.L.V.K.); (S.D.L.)
- Institut National de Transfusion Sanguine, F-75015 Paris, France
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, F-34293 Montpellier, France; (P.G.-M.); (S.K.); (N.T.)
| | - Claude Hattab
- Inserm, BIGR, UMR_S1134, Université de Paris, F-75015 Paris, France; (M.M.); (C.H.); (S.M.); (C.L.V.K.); (S.D.L.)
- Institut National de Transfusion Sanguine, F-75015 Paris, France
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, F-34293 Montpellier, France; (P.G.-M.); (S.K.); (N.T.)
| | - Pedro Gonzalez-Menendez
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, F-34293 Montpellier, France; (P.G.-M.); (S.K.); (N.T.)
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France
| | - Suella Martino
- Inserm, BIGR, UMR_S1134, Université de Paris, F-75015 Paris, France; (M.M.); (C.H.); (S.M.); (C.L.V.K.); (S.D.L.)
- Institut National de Transfusion Sanguine, F-75015 Paris, France
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, F-34293 Montpellier, France; (P.G.-M.); (S.K.); (N.T.)
| | - Jerome Larghero
- Unité de Thérapie cellulaire, AP-HP, Hôpital Saint-Louis, F-75010 Paris, France;
| | - Caroline Le Van Kim
- Inserm, BIGR, UMR_S1134, Université de Paris, F-75015 Paris, France; (M.M.); (C.H.); (S.M.); (C.L.V.K.); (S.D.L.)
- Institut National de Transfusion Sanguine, F-75015 Paris, France
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, F-34293 Montpellier, France; (P.G.-M.); (S.K.); (N.T.)
| | - Sandrina Kinet
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, F-34293 Montpellier, France; (P.G.-M.); (S.K.); (N.T.)
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France
| | - Naomi Taylor
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, F-34293 Montpellier, France; (P.G.-M.); (S.K.); (N.T.)
- Laboratoire d’Excellence GR-Ex, F-75015 Paris, France
- Pediatric Oncology Branch, Center for Cancer Research (CCR), National Cancer Institute (NCI), National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Sophie D. Lefevre
- Inserm, BIGR, UMR_S1134, Université de Paris, F-75015 Paris, France; (M.M.); (C.H.); (S.M.); (C.L.V.K.); (S.D.L.)
- Institut National de Transfusion Sanguine, F-75015 Paris, France
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, F-34293 Montpellier, France; (P.G.-M.); (S.K.); (N.T.)
| | - Mariano A. Ostuni
- Inserm, BIGR, UMR_S1134, Université de Paris, F-75015 Paris, France; (M.M.); (C.H.); (S.M.); (C.L.V.K.); (S.D.L.)
- Institut National de Transfusion Sanguine, F-75015 Paris, France
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, F-34293 Montpellier, France; (P.G.-M.); (S.K.); (N.T.)
- Correspondence: ; Tel.: +33‐1‐4449‐3135
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Manceau H, Lefevre SD, Mirmiran A, Hattab C, Sugier HR, Schmitt C, Peoc'h K, Puy H, Ostuni MA, Gouya L, Lacapere JJ. TSPO2 translocates 5-aminolevulinic acid into human erythroleukemia cells. Biol Cell 2020; 112:113-126. [PMID: 31989647 DOI: 10.1111/boc.201900098] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND 5-Aminolevulinic acid (ALA) is the first precursor of heme biosynthesis pathway. The exogenous addition of ALA to cells leads to protoporphyrin IX (PPIX) accumulation that has been exploited in photodynamic diagnostic and photodynamic therapy. Several types of ALA transporters have been described depending on the cell type, but there was no clear entry pathway for erythroid cells. The 18 kDa translocator protein (TSPO) has been proposed to be involved in the transport of porphyrins and heme analogs. RESULTS ALA-induced PPIX accumulation in erythroleukemia cells (UT-7 and K562) was impaired by PK 11195, a competitive inhibitor of both transmembrane proteins TSPO (1 and 2). PK 11195 did not modify the activity of the enzymes of heme biosynthesis, suggesting that ALA entry at the plasma membrane was the limiting factor. In contrast, porphobilinogen (PBG)-induced PPIX accumulation was not affected by PK 11195, suggesting that plasma membrane TSPO2 is a selective transporter of ALA. Overexpression of TSPO2 at the plasma membrane of erythroleukemia cells increased ALA-induced PPIX accumulation, confirming the role of TSPO2 in the import of ALA into the cells. CONCLUSIONS ALA-induced PPIX accumulation in erythroid cells involves TSPO2 as a selective translocator through the plasma membrane. SIGNIFICANCE This is the first characterisation of molecular mechanisms involving a new actor in ALA transport in ALA-induced PPIX accumulation in erythroleukemia cells, which could be inhibited by specific drug ligands.
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Affiliation(s)
- Hana Manceau
- Centre de recherche sur l'inflammation, INSERM U1149, Université de Paris, F-75018, Paris, France
- Laboratoire de Biochimie, Hôpital Beaujon, Assistance Publique-Hôpitaux de Paris, DHU Unity, 92110, Clichy, France
| | - Sophie D Lefevre
- UMR_S1134, Integrated Biology of Red Blood Cell, INSERM, Université de Paris, F-75015, Paris, France
- Institut National de Transfusion Sanguine, F-75015, Paris, France
| | - Arienne Mirmiran
- Centre de recherche sur l'inflammation, INSERM U1149, Université de Paris, F-75018, Paris, France
| | - Claude Hattab
- UMR_S1134, Integrated Biology of Red Blood Cell, INSERM, Université de Paris, F-75015, Paris, France
- Institut National de Transfusion Sanguine, F-75015, Paris, France
| | - Hugo R Sugier
- Institut National de Transfusion Sanguine, F-75015, Paris, France
- Université de Paris, UMR_S1134, Integrated Biology of Red Blood Cell, INSERM, F-75015, Paris, France
| | - Caroline Schmitt
- Centre de recherche sur l'inflammation, INSERM U1149, Université de Paris, F-75018, Paris, France
- Centre Français des Porphyries, Hôpital Louis Mourier, Assistance Publique-Hôpitaux de Paris, 92701, Colombes, France
| | - Katell Peoc'h
- Centre de recherche sur l'inflammation, INSERM U1149, Université de Paris, F-75018, Paris, France
- Laboratoire de Biochimie, Hôpital Beaujon, Assistance Publique-Hôpitaux de Paris, DHU Unity, 92110, Clichy, France
| | - Hervé Puy
- Centre de recherche sur l'inflammation, INSERM U1149, Université de Paris, F-75018, Paris, France
- Centre Français des Porphyries, Hôpital Louis Mourier, Assistance Publique-Hôpitaux de Paris, 92701, Colombes, France
| | - Mariano A Ostuni
- UMR_S1134, Integrated Biology of Red Blood Cell, INSERM, Université de Paris, F-75015, Paris, France
- Institut National de Transfusion Sanguine, F-75015, Paris, France
| | - Laurent Gouya
- Centre de recherche sur l'inflammation, INSERM U1149, Université de Paris, F-75018, Paris, France
- Centre Français des Porphyries, Hôpital Louis Mourier, Assistance Publique-Hôpitaux de Paris, 92701, Colombes, France
| | - Jean-Jacques Lacapere
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS, Laboratoire des Biomolécules (LBM), F-75005, Paris, France
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Tonon MC, Vaudry H, Chuquet J, Guillebaud F, Fan J, Masmoudi-Kouki O, Vaudry D, Lanfray D, Morin F, Prevot V, Papadopoulos V, Troadec JD, Leprince J. Endozepines and their receptors: Structure, functions and pathophysiological significance. Pharmacol Ther 2020; 208:107386. [DOI: 10.1016/j.pharmthera.2019.06.008] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 06/20/2019] [Indexed: 02/06/2023]
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Marginedas-Freixa I, Alvarez CL, Moras M, Hattab C, Bouyer G, Chene A, Lefevre SD, Le Van Kim C, Bihel F, Schwarzbaum PJ, Ostuni MA. Induction of ATP Release, PPIX Transport, and Cholesterol Uptake by Human Red Blood Cells Using a New Family of TSPO Ligands. Int J Mol Sci 2018; 19:ijms19103098. [PMID: 30308949 PMCID: PMC6213633 DOI: 10.3390/ijms19103098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/05/2018] [Accepted: 10/07/2018] [Indexed: 02/07/2023] Open
Abstract
Two main isoforms of the Translocator Protein (TSPO) have been identified. TSPO1 is ubiquitous and is mainly present at the outer mitochondrial membrane of most eukaryotic cells, whereas, TSPO2 is specific to the erythroid lineage, located at the plasma membrane, the nucleus, and the endoplasmic reticulum. The design of specific tools is necessary to determine the molecular associations and functions of TSPO, which remain controversial nowadays. We recently demonstrated that TSPO2 is involved in a supramolecular complex of the erythrocyte membrane, where micromolar doses of the classical TSPO ligands induce ATP release and zinc protoporphyrin (ZnPPIX) transport. In this work, three newly-designed ligands (NCS1016, NCS1018, and NCS1026) were assessed for their ability to modulate the functions of various erythrocyte's and compare them to the TSPO classical ligands. The three new ligands were effective in reducing intraerythrocytic Plasmodium growth, without compromising erythrocyte survival. While NCS1016 and NCS1018 were the most effective ligands in delaying sorbitol-induced hemolysis, NCS1016 induced the highest uptake of ZnPPIX and NCS1026 was the only ligand inhibiting the cholesterol uptake. Differential effects of ligands are probably due, not only, to ligand features, but also to the dynamic interaction of TSPO with various partners at the cell membrane. Further studies are necessary to fully understand the mechanisms of the TSPO's complex activation.
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Affiliation(s)
- Irene Marginedas-Freixa
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Cora L Alvarez
- Instituto de Química y Fisico-Química Biológicas "Prof. Alejandro C. Paladini", UBA, CONICET, Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina.
- Departamento de Biodiversidad y Biología Experimental, Facultad Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1113AAD Buenos Aires, Argentina.
| | - Martina Moras
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Claude Hattab
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Guillaume Bouyer
- UMR 8227 LBI2M, Comparative Erythrocyte's Physiology, CNRS, Sorbonne Université, Laboratoire d'Excellence GR-Ex, F-29680 Roscoff, France.
| | - Arnaud Chene
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Sophie D Lefevre
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Caroline Le Van Kim
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
| | - Frederic Bihel
- UMR7200, Laboratoire d'Innovation Thérapeutique, Faculty of Pharmacy, University of Strasbourg, CNRS, F-67400 Illkirch Graffenstaden, France.
| | - Pablo J Schwarzbaum
- Instituto de Química y Fisico-Química Biológicas "Prof. Alejandro C. Paladini", UBA, CONICET, Facultad de Farmacia y Bioquímica, Junín 956, C1113AAD Buenos Aires, Argentina.
- Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, C1113AAD Buenos Aires, Argentina.
| | - Mariano A Ostuni
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015 Paris, France.
- Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015 Paris, France.
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Marginedas-Freixa I, Alvarez CL, Moras M, Leal Denis MF, Hattab C, Halle F, Bihel F, Mouro-Chanteloup I, Lefevre SD, Le Van Kim C, Schwarzbaum PJ, Ostuni MA. Human erythrocytes release ATP by a novel pathway involving VDAC oligomerization independent of pannexin-1. Sci Rep 2018; 8:11384. [PMID: 30061676 PMCID: PMC6065367 DOI: 10.1038/s41598-018-29885-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 07/20/2018] [Indexed: 12/14/2022] Open
Abstract
We previously demonstrated that the translocase protein TSPO2 together with the voltage-dependent anion channel (VDAC) and adenine nucleotide transporter (ANT) were involved in a membrane transport complex in human red blood cells (RBCs). Because VDAC was proposed as a channel mediating ATP release in RBCs, we used TSPO ligands together with VDAC and ANT inhibitors to test this hypothesis. ATP release was activated by TSPO ligands, and blocked by inhibitors of VDAC and ANT, while it was insensitive to pannexin-1 blockers. TSPO ligand increased extracellular ATP (ATPe) concentration by 24–59% over the basal values, displaying an acute increase in [ATPe] to a maximal value, which remained constant thereafter. ATPe kinetics were compatible with VDAC mediating a fast but transient ATP efflux. ATP release was strongly inhibited by PKC and PKA inhibitors as well as by depleting intracellular cAMP or extracellular Ca2+, suggesting a mechanism involving protein kinases. TSPO ligands favoured VDAC polymerization yielding significantly higher densities of oligomeric bands than in unstimulated cells. Polymerization was partially inhibited by decreasing Ca2+ and cAMP contents. The present results show that TSPO ligands induce polymerization of VDAC, coupled to activation of ATP release by a supramolecular complex involving VDAC, TSPO2 and ANT.
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Affiliation(s)
- Irene Marginedas-Freixa
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015, Paris, France
| | - Cora Lilia Alvarez
- Instituto de Química y Fisico-Química Biológicas "Prof. Alejandro C. Paladini", UBA, CONICET, Facultad de Farmacia y Bioquímica, Junín 956, Buenos Aires, Argentina.,Universidad de Buenos Aires. Facultad Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
| | - Martina Moras
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015, Paris, France
| | - María Florencia Leal Denis
- Instituto de Química y Fisico-Química Biológicas "Prof. Alejandro C. Paladini", UBA, CONICET, Facultad de Farmacia y Bioquímica, Junín 956, Buenos Aires, Argentina.,Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Analítica y Fisicoquímica, Cátedra de Química Analítica, Buenos Aires, Argentina
| | - Claude Hattab
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015, Paris, France
| | - François Halle
- UMR7200, Laboratoire d'Innovation Thérapeutique, Faculty of Pharmacy, University of Strasbourg, CNRS, 67400, Illkirch Graffenstaden, France
| | - Frédéric Bihel
- UMR7200, Laboratoire d'Innovation Thérapeutique, Faculty of Pharmacy, University of Strasbourg, CNRS, 67400, Illkirch Graffenstaden, France
| | - Isabelle Mouro-Chanteloup
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015, Paris, France
| | - Sophie Denise Lefevre
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015, Paris, France
| | - Caroline Le Van Kim
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015, Paris, France.,Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015, Paris, France
| | - Pablo Julio Schwarzbaum
- Instituto de Química y Fisico-Química Biológicas "Prof. Alejandro C. Paladini", UBA, CONICET, Facultad de Farmacia y Bioquímica, Junín 956, Buenos Aires, Argentina.,Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica. Cátedra de Química Biológica Superior, Buenos Aires, Argentina
| | - Mariano Anibal Ostuni
- UMR-S1134, Integrated Biology of Red Blood Cells, INSERM, Université Paris Diderot, Sorbonne Paris Cité, Université de la Réunion, Université des Antilles, F-75015, Paris, France. .,Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, F-75015, Paris, France.
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Okazaki Y, Glass J. Protoporphyrin IX regulates peripheral benzodiazepine receptor associated protein 7 (PAP7) and divalent metal transporter 1 (DMT1) in K562 cells. Biochem Biophys Rep 2017; 10:26-31. [PMID: 28955733 PMCID: PMC5614651 DOI: 10.1016/j.bbrep.2017.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 02/17/2017] [Accepted: 02/25/2017] [Indexed: 11/28/2022] Open
Abstract
Background Protoporphyrin IX (PP IX), the immediate precursor to heme, combines with ferrous iron to make this product. The effects of exogenous PP IX on iron metabolism remain to be elucidated. Peripheral-type benzodiazepine receptor (PBR) is implicated in the transport of coproporphyrinogen into the mitochondria for conversion to PP IX. We have demonstrated that PBR-Associated Protein 7 (PAP7) bound to the Iron Responsive Element (IRE) isoform of divalent metal transporter 1 (DMT1). PP IX and PAP7 are ligands for PBR, thus, we hypothesized that PAP7 interact with PP IX via PBR. Methods We have examined in K562 cells, which can be induced to undergo erythroid differentiation by PP IX and hemin, the effects of PP IX on the expression of PAP7 and other proteins involved in cellular iron metabolism, transferrin receptor 1 (TfR1), DMT1, ferritin heavy chain (FTH), c-Myc and C/EBPα by western blot and quantitative real time PCR analyses. Results PP IX significantly decreased mRNA levels of DMT1 (IRE) and (non-IRE) from 4 h. PP IX markedly decreased protein levels of C/EBPα, PAP7 and DMT1. In contrast, hemin, which like PP IX also induces K562 cell differentiation, had no effect on PAP7 or DMT1 expression. Conclusion We hypothesize that PP IX binds to PBR displacing PAP7 protein, which is then degraded, decreasing the interaction of PAP7 with DMT1 (IRE) and resulting in increased turnover of DMT1. General significance These results suggest that exogenous PP IX disrupts iron metabolism by decreasing the protein expression levels of PAP7, DMT1 and C/EBPα. Protoporphyrin IX (PP IX) decreased protein levels of PAP7 and DMT1 in K562. PP IX decreased mRNA levels of DMT1 (IRE) and (non-IRE) isoforms in K562. PP IX decreased protein level of C/EBPα, which transcribes DMT1 mRNA, in K562.
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Affiliation(s)
- Yasumasa Okazaki
- Feist-Weiller Cancer Center and the Department of Medicine, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71130, USA
| | - Jonathan Glass
- Feist-Weiller Cancer Center and the Department of Medicine, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA 71130, USA
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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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Tremoleda JL, Thau-Zuchman O, Davies M, Foster J, Khan I, Vadivelu KC, Yip PK, Sosabowski J, Trigg W, Michael-Titus AT. In vivo PET imaging of the neuroinflammatory response in rat spinal cord injury using the TSPO tracer [(18)F]GE-180 and effect of docosahexaenoic acid. Eur J Nucl Med Mol Imaging 2016; 43:1710-22. [PMID: 27154521 PMCID: PMC4932147 DOI: 10.1007/s00259-016-3391-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/04/2016] [Indexed: 12/30/2022]
Abstract
Purpose Traumatic spinal cord injury (SCI) is a devastating condition which affects millions of people worldwide causing major disability and substantial socioeconomic burden. There are currently no effective treatments. Modulating the neuroinflammatory (NI) response after SCI has evolved as a major therapeutic strategy. PET can be used to detect the upregulation of the 18-kDa translocator protein (TSPO), a hallmark of activated microglia in the CNS. We investigated whether PET imaging using the novel TSPO tracer [18F]GE-180 can be used as a clinically relevant biomarker for NI in a contusion SCI rat model, and we present data on the modulation of NI by the lipid docosahexaenoic acid (DHA). Methods A total of 22 adult male Wistar rats were subjected to controlled spinal cord contusion at the T10 spinal cord level. Six non-injured and ten T10 laminectomy only (LAM) animals were used as controls. A subset of six SCI animals were treated with a single intravenous dose of 250 nmol/kg DHA (SCI-DHA group) 30 min after injury; a saline-injected group of six animals was used as an injection control. PET and CT imaging was carried out 7 days after injury using the [18F]GE-180 radiotracer. After imaging, the animals were killed and the spinal cord dissected out for biodistribution and autoradiography studies. In vivo data were correlated with ex vivo immunohistochemistry for TSPO. Results In vivo dynamic PET imaging revealed an increase in tracer uptake in the spinal cord of the SCI animals compared with the non-injured and LAM animals from 35 min after injection (P < 0.0001; SCI vs. LAM vs. non-injured). Biodistribution and autoradiography studies confirmed the high affinity and specific [18F]GE-180 binding in the injured spinal cord compared with the binding in the control groups. Furthermore, they also showed decreased tracer uptake in the T10 SCI area in relation to the non-injured remainder of the spinal cord in the SCI-DHA group compared with the SCI-saline group (P < 0.05), supporting a NI modulatory effect of DHA. Immunohistochemistry showed a high level of TSPO expression (38 %) at the T10 injury site in SCI animals compared with that in the non-injured animals (6 %). Conclusion [18F]GE-180 PET imaging can reveal areas of increased TSPO expression that can be visualized and quantified in vivo after SCI, offering a minimally invasive approach to the monitoring of NI in SCI models and providing a translatable clinical readout for the testing of new therapies. Electronic supplementary material The online version of this article (doi:10.1007/s00259-016-3391-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- J L Tremoleda
- Centre for Trauma Sciences, The Blizard Institute, London, UK.
| | - O Thau-Zuchman
- Centre for Trauma Sciences, The Blizard Institute, London, UK
| | - M Davies
- Centre for Trauma Sciences, The Blizard Institute, London, UK
| | - J Foster
- Barts Cancer Institute, Queen Mary University London, London, UK
| | - I Khan
- GE Healthcare Ltd, Amersham, UK
| | - K C Vadivelu
- Centre for Trauma Sciences, The Blizard Institute, London, UK
| | - P K Yip
- Centre for Trauma Sciences, The Blizard Institute, London, UK
| | - J Sosabowski
- Barts Cancer Institute, Queen Mary University London, London, UK
| | - W Trigg
- GE Healthcare Ltd, Amersham, UK
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9
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Aghazadeh Y, Zirkin BR, Papadopoulos V. Pharmacological regulation of the cholesterol transport machinery in steroidogenic cells of the testis. VITAMINS AND HORMONES 2015; 98:189-227. [PMID: 25817870 DOI: 10.1016/bs.vh.2014.12.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Reduced serum testosterone (T), or hypogonadism, is estimated to affect about 5 million American men, including both aging and young men. Low serum T has been linked to mood changes, worsening cognition, fatigue, depression, decreased lean body mass and bone mineral density, increased visceral fat, metabolic syndrome, decreased libido, and sexual dysfunction. Administering exogenous T, known as T-replacement therapy (TRT), reverses many of the symptoms of low T levels. However, this treatment can result in luteinizing hormone suppression which, in turn, can lead to reduced sperm numbers and infertility, making TRT inappropriate for men who wish to father children. Additionally, TRT may result in supraphysiologic T levels, skin irritation, and T transfer to others upon contact; and there may be increased risk of prostate cancer and cardiovascular disease, particularly in aging men. Therefore, the development of alternate therapies for treating hypogonadism would be highly desirable. To do so requires greater understanding of the series of steps leading to T formation and how they are regulated, and the identification of key steps that are amenable to pharmacological modulation so as to induce T production. We review herein our current understanding of mechanisms underlying the pharmacological induction of T formation in hypogonadal testis.
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Affiliation(s)
- Yasaman Aghazadeh
- The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada
| | - Barry R Zirkin
- Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Vassilios Papadopoulos
- The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada; Department of Medicine, McGill University, Montreal, Quebec, Canada; Department of Biochemistry, McGill University, Montreal, Quebec, Canada; Department of Pharmacology & Therapeutics, McGill University, Montreal, Quebec, Canada.
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Hinsen K, Vaitinadapoule A, Ostuni MA, Etchebest C, Lacapere JJ. Construction and validation of an atomic model for bacterial TSPO from electron microscopy density, evolutionary constraints, and biochemical and biophysical data. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:568-80. [PMID: 25450341 DOI: 10.1016/j.bbamem.2014.10.028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/01/2014] [Accepted: 10/20/2014] [Indexed: 11/30/2022]
Abstract
The 18 kDa protein TSPO is a highly conserved transmembrane protein found in bacteria, yeast, animals and plants. TSPO is involved in a wide range of physiological functions, among which the transport of several molecules. The atomic structure of monomeric ligand-bound mouse TSPO in detergent has been published recently. A previously published low-resolution structure of Rhodobacter sphaeroides TSPO, obtained from tubular crystals with lipids and observed in cryo-electron microscopy, revealed an oligomeric structure without any ligand. We analyze this electron microscopy density in view of available biochemical and biophysical data, building a matching atomic model for the monomer and then the entire crystal. We compare its intra- and inter-molecular contacts with those predicted by amino acid covariation in TSPO proteins from evolutionary sequence analysis. The arrangement of the five transmembrane helices in a monomer of our model is different from that observed for the mouse TSPO. We analyze possible ligand binding sites for protoporphyrin, for the high-affinity ligand PK 11195, and for cholesterol in TSPO monomers and/or oligomers, and we discuss possible functional implications.
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Affiliation(s)
- Konrad Hinsen
- Centre de Biophysique Moléculaire (CNRS), Rue Charles Sadron, 45071 Orléans Cedex, France; Synchrotron SOLEIL, Division Expériences, Saint Aubin, B.P. 48, 91192 Gif-sur-Yvette Cedex, France.
| | - Aurore Vaitinadapoule
- INSERM, UMR-S1134, 6 rue Alexandre Cabanel, Université Paris 7 Denis Diderot, F-75015 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut National de la Transfusion Sanguine (INTS), Paris, France; GR-Ex, Laboratoire d'Excellence, Paris, France; National Centre for Biological Sciences (NCBS), Tata Institute for Fundamental Research, GKVK Campus, Bangalore, Karnataka, India; Dynamique des Structures et des Interactions des des Macromolécules Biologiques, France.
| | - Mariano A Ostuni
- INSERM, UMR-S1134, 6 rue Alexandre Cabanel, Université Paris 7 Denis Diderot, F-75015 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut National de la Transfusion Sanguine (INTS), Paris, France; GR-Ex, Laboratoire d'Excellence, Paris, France.
| | - Catherine Etchebest
- INSERM, UMR-S1134, 6 rue Alexandre Cabanel, Université Paris 7 Denis Diderot, F-75015 Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France; Institut National de la Transfusion Sanguine (INTS), Paris, France; GR-Ex, Laboratoire d'Excellence, Paris, France; Dynamique des Structures et des Interactions des des Macromolécules Biologiques, France.
| | - Jean-Jacques Lacapere
- Sorbonne Universités, UPMC Univ Paris 06, Laboratoire de Biomolécules (LBM), 4 Place Jussieu, F-75005 Paris, France; Ecole Normale Supérieure - PSL Research University, Département de Chimie, 24, rue Lhomond, 75005 Paris, France; CNRS, UMR 7203 LBM, F-75005 Paris, France.
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11
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Wang HJ, Fan J, Papadopoulos V. Translocator protein (Tspo) gene promoter-driven green fluorescent protein synthesis in transgenic mice: an in vivo model to study Tspo transcription. Cell Tissue Res 2012; 350:261-75. [PMID: 22868914 DOI: 10.1007/s00441-012-1478-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 06/26/2012] [Indexed: 12/11/2022]
Abstract
Translocator protein (TSPO), previously known as the peripheral-type benzodiazepine receptor, is a ubiquitous drug- and cholesterol-binding protein primarily found in the outer mitochondrial membrane as part of a mitochondrial cholesterol transport complex. TSPO is present at higher levels in steroid-synthesizing and rapidly proliferating tissues and its biological role has been mainly linked to mitochondrial function, steroidogenesis and cell proliferation/apoptosis. Aberrant TSPO levels have been linked to multiple diseases, including cancer, endocrine disorders, brain injury, neurodegeneration, ischemia-reperfusion injury and inflammatory diseases. Investigation of the functions of this protein in vitro and in vivo have been mainly carried out using high-affinity drug ligands, such as isoquinoline carboxamides and benzodiazepines and more recently, gene silencing methods. To establish a model to study the regulation of Tspo transcription in vivo, we generated a transgenic mouse model expressing green fluorescent protein (GFP) from Aequorea coerulescens under control of the Tspo promoter region (Tspo-AcGFP). The expression profiles of Tspo-AcGFP, endogenous TSPO and Tspo mRNA were found to be well-correlated. Tspo-AcGFP synthesis in the transgenic mice was seen in almost every tissue examined and as with TSPO in wild-type mice, Tspo-AcGFP was highly expressed in steroidogenic cells of the endocrine and reproductive systems, epithelial cells of the digestive system, skeletal muscle and other organs. In summary, this transgenic Tspo-AcGFP mouse model recapitulates endogenous Tspo expression patterns and could be a useful, tractable tool for monitoring the transcriptional regulation and function of Tspo in live animal experiments.
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Affiliation(s)
- Hui-Jie Wang
- The Research Institute of the McGill University Health Center, McGill University, Montréal, Québec, H3A 1A4, Canada
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12
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Teboul D, Beaufils S, Taveau JC, Iatmanen-Harbi S, Renault A, Venien-Bryan C, Vie V, Lacapere JJ. Mouse TSPO in a lipid environment interacting with a functionalized monolayer. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:2791-800. [PMID: 22771765 DOI: 10.1016/j.bbamem.2012.06.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 06/11/2012] [Accepted: 06/26/2012] [Indexed: 12/28/2022]
Abstract
Translocator protein TSPO is a membrane protein highly conserved in evolution which does not belong to any structural known family. TSPO is involved in physiological functions among which transport of molecules such as cholesterol to form steroids and bile salts in mammalian cells. Membrane protein structure determination remains a difficult task and needs concomitant approaches (for instance X-ray- or Electron-crystallography and NMR). Electron microscopy and two-dimensional crystallization under functionalized monolayers have been successfully developed for recombinant tagged proteins. The difficulty comes from the detergent carried by membrane proteins that disrupt the lipid monolayer. We identified the best conditions for injecting the histidine tagged recombinant TSPO in detergent in the subphase and to keep the protein stable. Reconstituted recombinant protein into a lipid bilayer favors its adsorption to functionalized monolayers and limits the disruption of the monolayer by reducing the amount of detergent. Finally, we obtained the first transmission electron microscopy images of recombinant mouse TSPO negatively stained bound to the lipid monolayer after injection into the subphase of pre-reconstituted TSPO in lipids. Image analysis reveals that circular objects could correspond to an association of at least four monomers of mouse TSPO. The different amino acid compositions and the location of the polyhistidine tag between bacterial and mouse TSPO could account for the formation of dimer versus tetramer, respectively. The difference in the loop between the first and second putative transmembrane domain may contribute to distinct monomer interaction, this is supported by differences in ligand binding parameters and biological functions of both proteins.
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Lauffer S, Mäbert K, Czupalla C, Pursche T, Hoflack B, Rödel G, Krause-Buchholz U. Saccharomyces cerevisiae porin pore forms complexes with mitochondrial outer membrane proteins Om14p and Om45p. J Biol Chem 2012; 287:17447-17458. [PMID: 22461620 DOI: 10.1074/jbc.m111.328328] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Numerous transport processes occur between the two mitochondrial (mt) membranes due to the diverse functions and metabolic processes of the mt organelle. The metabolite and ion transport through the mt outer membrane (OM) is widely assumed to be mediated by the porin pore, whereas in the mt inner membrane (IM) specific carriers are responsible for transport processes. Here, we provide evidence by means of Blue Native (BN)-PAGE analysis, co-immunoprecipitation, and tandem affinity purification that the two mt OM proteins Om14p and Om45p associate with the porin pore. Porin molecules seem to assemble independently to build the core unit. A subpopulation of these core units interacts with Om14p and Om45p. With preparative tandem affinity purification followed by MS analysis, we could identify interaction partners of this OM complex, which are mainly localized within the mt IM and function as carriers for diverse molecules. We propose a model for the role of the two OM proteins in addressing the porin pore to bind to specific channels in the mt IM to facilitate transport of metabolites.
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Affiliation(s)
- Susann Lauffer
- Institute of Genetics, Technische Universität Dresden, 01062 Dresden and.
| | - Katrin Mäbert
- Institute of Genetics, Technische Universität Dresden, 01062 Dresden and
| | - Cornelia Czupalla
- Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Theresia Pursche
- Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Bernard Hoflack
- Biotechnology Center, Technische Universität Dresden, Tatzberg 47/49, 01307 Dresden, Germany
| | - Gerhard Rödel
- Institute of Genetics, Technische Universität Dresden, 01062 Dresden and
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Papadopoulos V, Lecanu L. Caprospinol: discovery of a steroid drug candidate to treat Alzheimer's disease based on 22R-hydroxycholesterol structure and properties. J Neuroendocrinol 2012; 24:93-101. [PMID: 21623958 DOI: 10.1111/j.1365-2826.2011.02167.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The overall ability of the brain to synthesise neuroactive steroids led us to the identification of compounds that would reproduce aspects of neurosteroid pharmacology. The rate-determining step in neurosteroid biosynthesis is the import of the substrate cholesterol into the mitochondria, where it is metabolised into pregnenolone via the intermediate 22R-hydroxycholesterol. The levels of translocator protein 18-kDa, mediating the import of cholesterol into mitochondria, correlated with increased pregnenolone formation and reduced levels of 22R-hydroxycholesterol in biopsies from Alzheimer's disease (AD), but not age-matched control, brains. 22R-hydroxycholesterol was shown to protect against β-amyloid (Aβ(42) )-induced neurotoxicity. In search of 22R-hydroxycholesterol stable analogues, we identified the naturally occurring heterospirostenol, (22R,25R)-20α-spirost-5-en-3β-yl hexanoate (caprospinol) and derivatives that protect neuronal cells against Aβ(1-42) neurotoxicity. The neuroprotective effect of caprospinol is the result of a combination of overlapping properties, including: (i) the ability to bind to Aβ(42) and reduce plaque formation in the brain in vivo; (ii) interaction with components of the mitochondria respiratory chain resulting in an anti-uncoupling effect; (iii) the capacity to scavenge Aβ(42) monomers present in mitochondria; and (iv) the property of being a sigma-1 receptor ligand. In vivo, caprospinol crosses the blood-brain barrier, accumulates in the brain, and restores cognitive impairment in a pharmacological rat model of AD. Caprospinol is stable, does not bind to known steroid receptors, is devoid of mutagenic and genotoxic properties, and is devoid of acute toxicity in rodents. The pharmacokinetics and pharmacodynamics of caprospinol were studied, and long-term toxicity studies are under investigation, aiming to develop this compound as a disease-modifying drug for the treatment of AD.
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Affiliation(s)
- V Papadopoulos
- The Research Institute of the McGill University Health Centre and Department of Medicine, McGill University, Montreal, Canada.
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15
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Ostuni MA, Issop L, Péranzi G, Walker F, Fasseu M, Elbim C, Papadopoulos V, Lacapere JJ. Overexpression of translocator protein in inflammatory bowel disease: potential diagnostic and treatment value. Inflamm Bowel Dis 2010; 16:1476-87. [PMID: 20222126 PMCID: PMC2930116 DOI: 10.1002/ibd.21250] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Inflammatory bowel diseases (IBDs), such as ulcerative colitis and Crohn's disease, are chronic inflammatory disorders that increase the risk for colorectal cancer. The mitochondrial translocator protein (TSPO) is a high-affinity drug- and cholesterol-binding protein expressed in the colon and its expression is increased in colon cancers. The aim of this study was to investigate TSPO expression in IBD biopsies and to establish an animal model of IBD to examine the role of TSPO. In addition, we evaluated the potential use of TSPO drug ligands in diagnosing and treating IBD. METHODS TSPO expression in IBD biopsies was evaluated using immunohistochemistry. IBD was induced in a rat experimental model via treatment with dextran sodium sulfate (DSS). Colon morphology, TSPO expression, and proinflammatory cytokine production were evaluated in addition to the effect of TSPO drug ligands on disease pathology. RESULTS TSPO protein levels were elevated in the enterocytes of IBD biopsies. TSPO expression was localized to the enterocyte mitochondria. DSS treatment induced a time-dependent phenotype mimicking IBD with tissue injury and subsequent tissue regeneration. Coadministration of DSS and the TSPO drug ligands PK 11195 or Ro5-4864 increased both the rate of colon ulceration and regeneration, whereas administration of the TSPO drug ligand flunitrazepam partially prevented this pathology. These data correlated with changes in proinflammatory cytokine plasma levels, as well as increased cytokine production and secretion from the colon. CONCLUSIONS TSPO may serve as a marker of the IBD repair process, and TSPO drug ligands should be further evaluated for IBD treatment.
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Affiliation(s)
- Mariano A Ostuni
- Unité INSERM U773, Centre de Recherche Biomédicale Bichat Beaujon CRB3, Université Paris 7 Denis Diderot, Paris, France.
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