1
|
Cereso N, Pequignot MO, Robert L, Becker F, De Luca V, Nabholz N, Rigau V, De Vos J, Hamel CP, Kalatzis V. Proof of concept for AAV2/5-mediated gene therapy in iPSC-derived retinal pigment epithelium of a choroideremia patient. Mol Ther Methods Clin Dev 2014; 1:14011. [PMID: 26015956 PMCID: PMC4362346 DOI: 10.1038/mtm.2014.11] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 02/24/2014] [Indexed: 02/06/2023]
Abstract
Inherited retinal dystrophies (IRDs) comprise a large group of genetically and clinically heterogeneous diseases that lead to progressive vision loss, for which a paucity of disease-mimicking animal models renders preclinical studies difficult. We sought to develop pertinent human cellular IRD models, beginning with choroideremia, caused by mutations in the CHM gene encoding Rab escort protein 1 (REP1). We reprogrammed REP1-deficient fibroblasts from a CHM-/y patient into induced pluripotent stem cells (iPSCs), which we differentiated into retinal pigment epithelium (RPE). This iPSC-derived RPE is a polarized monolayer with a classic morphology, expresses characteristic markers, is functional for fluid transport and phagocytosis, and mimics the biochemical phenotype of patients. We assayed a panel of adeno-associated virus (AAV) vector serotypes and showed that AAV2/5 is the most efficient at transducing the iPSC-derived RPE and that CHM gene transfer normalizes the biochemical phenotype. The high, and unmatched, in vitro transduction efficiency is likely aided by phagocytosis and mimics the scenario that an AAV vector encounters in vivo in the subretinal space. We demonstrate the superiority of AAV2/5 in the human RPE and address the potential of patient iPSC–derived RPE to provide a proof-of-concept model for gene replacement in the absence of an appropriate animal model.
Collapse
Affiliation(s)
- Nicolas Cereso
- Inserm U1051, Institute for Neurosciences of Montpellier , Montpellier, France ; University of Montpellier 1 , Montpellier, France ; University of Montpellier 2 , Montpellier, France
| | - Marie O Pequignot
- Inserm U1051, Institute for Neurosciences of Montpellier , Montpellier, France ; University of Montpellier 1 , Montpellier, France ; University of Montpellier 2 , Montpellier, France
| | - Lorenne Robert
- Inserm U1051, Institute for Neurosciences of Montpellier , Montpellier, France ; University of Montpellier 1 , Montpellier, France ; University of Montpellier 2 , Montpellier, France
| | - Fabienne Becker
- Inserm U1040, Institute for Research in Biotherapy , Montpellier, France
| | - Valerie De Luca
- Inserm U1051, Institute for Neurosciences of Montpellier , Montpellier, France ; University of Montpellier 1 , Montpellier, France ; University of Montpellier 2 , Montpellier, France
| | - Nicolas Nabholz
- Inserm U1051, Institute for Neurosciences of Montpellier , Montpellier, France ; University of Montpellier 1 , Montpellier, France ; University of Montpellier 2 , Montpellier, France ; Department of Ophthalmology, CHRU , Montpellier, France
| | - Valerie Rigau
- Department of Anatomy and Pathological Cytology, CHRU , Montpellier, France
| | - John De Vos
- University of Montpellier 1 , Montpellier, France ; University of Montpellier 2 , Montpellier, France ; Inserm U1040, Institute for Research in Biotherapy , Montpellier, France ; Cellular Therapy Unit, CHRU , Montpellier, France
| | - Christian P Hamel
- Inserm U1051, Institute for Neurosciences of Montpellier , Montpellier, France ; University of Montpellier 1 , Montpellier, France ; University of Montpellier 2 , Montpellier, France ; Department of Ophthalmology, CHRU , Montpellier, France ; Centre of Reference for Genetic Sensory Diseases, CHRU , Montpellier, France
| | - Vasiliki Kalatzis
- Inserm U1051, Institute for Neurosciences of Montpellier , Montpellier, France ; University of Montpellier 1 , Montpellier, France ; University of Montpellier 2 , Montpellier, France
| |
Collapse
|
2
|
Chekroud K, Guillou L, Grégoire S, Ducharme G, Brun E, Cazevieille C, Bretillon L, Hamel CP, Brabet P, Pequignot MO. Fatp1 deficiency affects retinal light response and dark adaptation, and induces age-related alterations. PLoS One 2012; 7:e50231. [PMID: 23166839 PMCID: PMC3500375 DOI: 10.1371/journal.pone.0050231] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 10/19/2012] [Indexed: 11/19/2022] Open
Abstract
FATP1 is involved in lipid transport into cells and in intracellular lipid metabolism. We showed previously that this protein interacts with and inhibits the limiting-step isomerase of the visual cycle RPE65. Here, we aimed to analyze the effect of Fatp1-deficiency in vivo on the visual cycle, structure and function, and on retinal aging. Among the Fatp family members, we observed that only Fatp1 and 4 are expressed in the control retina, in both the neuroretina and the retinal pigment epithelium. In the neuroretina, Fatp1 is mostly expressed in photoreceptors. In young adult Fatp1−/− mice, Fatp4 expression was unchanged in retinal pigment epithelium and reduced two-fold in the neuroretina as compared to Fatp1+/+ mice. The Fatp1−/− mice had a preserved retinal structure but a decreased electroretinogram response to light. These mice also displayed a delayed recovery of the b-wave amplitude after bleaching, however, visual cycle speed was unchanged, and both retinal pigment epithelium and photoreceptors presented the same fatty acid pattern compared to controls. In 2 year-old Fatp1−/− mice, transmission electron microscopy studies showed specific abnormalities in the retinas comprising choroid vascularization anomalies and thickening of the Bruch membrane with material deposits, and sometimes local disorganization of the photoreceptor outer segments. These anomalies lead us to speculate that the absence of FATP1 accelerates the aging process.
Collapse
Affiliation(s)
- Karim Chekroud
- Inserm U1051, Institute for Neurosciences of Montpellier, CHU St Eloi, Montpellier, France
| | - Laurent Guillou
- Inserm U1051, Institute for Neurosciences of Montpellier, CHU St Eloi, Montpellier, France
| | | | - Gilles Ducharme
- CNRS UMR5149, Institut de Mathématiques et de Modélisation de Montpellier, France
| | - Emilie Brun
- Inserm U1051, Institute for Neurosciences of Montpellier, CHU St Eloi, Montpellier, France
| | | | | | - Christian P. Hamel
- Inserm U1051, Institute for Neurosciences of Montpellier, CHU St Eloi, Montpellier, France
| | - Philippe Brabet
- Inserm U1051, Institute for Neurosciences of Montpellier, CHU St Eloi, Montpellier, France
- * E-mail: (MOP); (PB)
| | - Marie O. Pequignot
- Inserm U1051, Institute for Neurosciences of Montpellier, CHU St Eloi, Montpellier, France
- * E-mail: (MOP); (PB)
| |
Collapse
|
3
|
Chekroud K, Arndt C, Basset D, Hamel CP, Brabet P, Pequignot MO. Simple and efficient: validation of a cotton wick electrode for animal electroretinography. Ophthalmic Res 2010; 45:174-9. [PMID: 21051915 DOI: 10.1159/000321118] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 09/16/2010] [Indexed: 11/19/2022]
Abstract
PURPOSE Electroretinography (ERG) is a widely used technique to test retinal function in humans and animals. Recordings are particularly dependent on the type of electrodes used, with the best electrodes often being expensive and not always easy to use. The need of a simple and effective electrode type has led us to search the efficacy of different types of electrodes used in practice and compare them with the modified cotton wick electrode. MATERIAL AND METHODS A modified type of electrode made of a cotton wick and impregnated with NaCl is described, and the ERG results were compared with other types of electrodes. RESULTS Compared with standard metal wire loop electrodes, the cotton wick electrode results in obtaining higher amplitudes, a better inter-eye correlation in the same animal and a better reproducibility of the recordings over time. CONCLUSION This cotton electrode is simple to make and easy to place. It provides reliable recordings during the entire life span of the animal and reliable comparisons between contralateral eyes, thus providing a powerful tool for ERG studies.
Collapse
Affiliation(s)
- Karim Chekroud
- Inserm U583, Institute for Neurosciences of Montpellier, CHU Saint-Eloi, Montpellier, France
| | | | | | | | | | | |
Collapse
|
4
|
Guignard TJP, Jin M, Pequignot MO, Li S, Chassigneux Y, Chekroud K, Guillou L, Richard E, Hamel CP, Brabet P. FATP1 inhibits 11-cis retinol formation via interaction with the visual cycle retinoid isomerase RPE65 and lecithin:retinol acyltransferase. J Biol Chem 2010; 285:18759-68. [PMID: 20356843 PMCID: PMC2881799 DOI: 10.1074/jbc.m109.064329] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 03/30/2010] [Indexed: 12/16/2022] Open
Abstract
The isomerization of all-trans retinol (vitamin A) to 11-cis retinol in the retinal pigment epithelium (RPE) is a key step in the visual process for the regeneration of the visual pigment chromophore, 11-cis retinal. LRAT and RPE65 are recognized as the minimal isomerase catalytic components. However, regulators of this rate-limiting step are not fully identified and could account for the phenotypic variability associated with inherited retinal degeneration (RD) caused by mutations in the RPE65 gene. To identify new RPE65 partners, we screened a porcine RPE mRNA library using a yeast two-hybrid assay with full-length human RPE65. One identified clone (here named FATP1c), containing the cytosolic C-terminal sequence from the fatty acid transport protein 1 (FATP1 or SLC27A1, solute carrier family 27 member 1), was demonstrated to interact dose-dependently with the native RPE65 and with LRAT. Furthermore, these interacting proteins colocalize in the RPE. Cellular reconstitution of human interacting proteins shows that FATP1 markedly inhibits 11-cis retinol production by acting on the production of all-trans retinyl esters and the isomerase activity of RPE65. The identification of this new visual cycle inhibitory component in RPE may contribute to further understanding of retinal pathogenesis.
Collapse
Affiliation(s)
- Thomas J. P. Guignard
- From the Inserm U583, Institut des Neurosciences de Montpellier, Montpellier, 34091 France
| | - Minghao Jin
- the Department of Ophthalmology, Neuroscience Center, Louisiana State University School of Medicine, New Orleans, Louisiana 70112, and
| | - Marie O. Pequignot
- From the Inserm U583, Institut des Neurosciences de Montpellier, Montpellier, 34091 France
| | - Songhua Li
- the Department of Ophthalmology, Neuroscience Center, Louisiana State University School of Medicine, New Orleans, Louisiana 70112, and
| | - Yolaine Chassigneux
- From the Inserm U583, Institut des Neurosciences de Montpellier, Montpellier, 34091 France
| | - Karim Chekroud
- From the Inserm U583, Institut des Neurosciences de Montpellier, Montpellier, 34091 France
| | - Laurent Guillou
- From the Inserm U583, Institut des Neurosciences de Montpellier, Montpellier, 34091 France
| | - Eric Richard
- the Centre de Biochimie Structurale CNRS UMR 5048-UM1-Inserm UMR 554, 29 rue de Navacelles, Montpellier, 34090 France
| | - Christian P. Hamel
- From the Inserm U583, Institut des Neurosciences de Montpellier, Montpellier, 34091 France
| | - Philippe Brabet
- From the Inserm U583, Institut des Neurosciences de Montpellier, Montpellier, 34091 France
- the University Montpellier 1, Montpellier, 34967 France
- the University Montpellier 2, Montpellier, 34095 France
| |
Collapse
|
5
|
Coquelle A, Mouhamad S, Pequignot MO, Braun T, Carvalho G, Vivet S, Métivier D, Castedo M, Kroemer G. Enrichment of non-synchronized cells in the G1, S and G2 phases of the cell cycle for the study of apoptosis. Biochem Pharmacol 2006; 72:1396-404. [PMID: 16765323 DOI: 10.1016/j.bcp.2006.04.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Revised: 03/30/2006] [Accepted: 04/11/2006] [Indexed: 11/16/2022]
Abstract
The susceptibility of cells to apoptosis induction is deeply influenced by their position in the cell cycle. Unfortunately, however, current methods for the enrichment of cells in defined phases of the cell cycle are mostly based on the synchronization of cells by agents or conditions that are intrinsically toxic and induce apoptosis on their own. We developed a novel procedure for the purification of cells in distinct phases of the cell cycle. This method is based on the stable transfection of cells with a chimeric protein made up by histone H2B and green fluorescent protein (GFP). Cytofluorometric purification of cells defined by their size and their H2B-GFP-dependent fluorescence (which reflects chromatin and hence DNA content) allowed for the efficient separation of diploid and tetraploid cells in the fluorescence-activated cell sorter (FACS). Moreover, when applied to diploid cells, this method allowed for the enrichment of live, functional cells in the G1, S and G2 phases of the cell cycle. FACS-purified cells were viable and readily resumed the cell cycle upon reculture. While staurosporine was equally toxic for cells in any phase of the cell cycle, camptothecin was particularly toxic for cells in the S phase. Moreover, BAY11-7082, a specific inhibitor of the IKK complex required for NF-kappaB activation, exhibited a particular cell cycle-specific profile of toxicity (G2>S>G1). These results delineate a novel procedure for studying the intersection between cell cycle regulation and cell death mechanisms.
Collapse
Affiliation(s)
- Arnaud Coquelle
- Centre National de la Recherche Scientifique, UMR8125, Institut Gustave Roussy, 39 rue Camille-Desmoulins, F-94805 Villejuif, France
| | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Coquelle A, Mouhamad S, Pequignot MO, Braun T, Carvalho G, Vivet S, Métivier D, Castedo M, Kroemer G. Cell cycle-dependent cytotoxic and cytostatic effects of bortezomib on colon carcinoma cells. Cell Death Differ 2006; 13:873-5. [PMID: 16498456 DOI: 10.1038/sj.cdd.4401881] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|
7
|
Castedo M, Coquelle A, Vivet S, Vitale I, Kauffmann A, Dessen P, Pequignot MO, Casares N, Valent A, Mouhamad S, Schmitt E, Modjtahedi N, Vainchenker W, Zitvogel L, Lazar V, Garrido C, Kroemer G. Apoptosis regulation in tetraploid cancer cells. EMBO J 2006; 25:2584-95. [PMID: 16675948 PMCID: PMC1478174 DOI: 10.1038/sj.emboj.7601127] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Accepted: 04/11/2006] [Indexed: 12/13/2022] Open
Abstract
Tetraploidy can result in cancer-associated aneuploidy. As shown here, freshly generated tetraploid cells arising due to mitotic slippage or failed cytokinesis are prone to undergo Bax-dependent mitochondrial membrane permeabilization and subsequent apoptosis. Knockout of Bax or overexpression of Bcl-2 facilitated the survival of tetraploid cells at least as efficiently as the p53 or p21 knockout. When tetraploid cells were derived from diploid p53 and Bax-proficient precursors, such cells exhibited an enhanced transcription of p53 target genes. Tetraploid cells exhibited an enhanced rate of spontaneous apoptosis that could be suppressed by inhibition of p53 or by knockdown of proapoptotic p53 target genes such as BBC3/Puma, GADD45A and ferredoxin reductase. Unexpectedly, tetraploid cells were more resistant to DNA damaging agents (cisplatin, oxaliplatin and camptothecin) than their diploid counterparts, and this difference disappeared upon inhibition of p53 or knockdown of p53-inducible ribonucleotide reductase. Tetraploid cells were also more resistant against UVC and gamma-irradiation. These data indicate the existence of p53-dependent alterations in apoptosis regulation in tetraploid cells.
Collapse
Affiliation(s)
- Maria Castedo
- CNRS, UMR8125, Institut Gustave Roussy, Villejuif, France
| | | | - Sonia Vivet
- CNRS, UMR8125, Institut Gustave Roussy, Villejuif, France
| | - Ilio Vitale
- CNRS, UMR8125, Institut Gustave Roussy, Villejuif, France
| | | | | | | | - Noelia Casares
- CNRS, UMR8125, Institut Gustave Roussy, Villejuif, France
| | - Alexandre Valent
- Unité de Génomique Fonctionnelle, Institut Gustave Roussy, Villejuif, France
| | | | - Elise Schmitt
- INSERM U-517, Faculty of Medicine and Pharmacy, Dijon, France
| | | | | | | | - Vladimir Lazar
- Unité de Génomique Fonctionnelle, Institut Gustave Roussy, Villejuif, France
| | - Carmen Garrido
- INSERM U-517, Faculty of Medicine and Pharmacy, Dijon, France
| | - Guido Kroemer
- CNRS, UMR8125, Institut Gustave Roussy, Villejuif, France
| |
Collapse
|
8
|
Casares N, Pequignot MO, Tesniere A, Ghiringhelli F, Roux S, Chaput N, Schmitt E, Hamai A, Hervas-Stubbs S, Obeid M, Coutant F, Métivier D, Pichard E, Aucouturier P, Pierron G, Garrido C, Zitvogel L, Kroemer G. Caspase-dependent immunogenicity of doxorubicin-induced tumor cell death. ACTA ACUST UNITED AC 2006; 202:1691-701. [PMID: 16365148 PMCID: PMC2212968 DOI: 10.1084/jem.20050915] [Citation(s) in RCA: 1063] [Impact Index Per Article: 59.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Systemic anticancer chemotherapy is immunosuppressive and mostly induces nonimmunogenic tumor cell death. Here, we show that even in the absence of any adjuvant, tumor cells dying in response to anthracyclins can elicit an effective antitumor immune response that suppresses the growth of inoculated tumors or leads to the regression of established neoplasia. Although both antracyclins and mitomycin C induced apoptosis with caspase activation, only anthracyclin-induced immunogenic cell death was immunogenic. Caspase inhibition by Z-VAD-fmk or transfection with the baculovirus inhibitor p35 did not inhibit doxorubicin (DX)-induced cell death, yet suppressed the immunogenicity of dying tumor cells in several rodent models of neoplasia. Depletion of dendritic cells (DCs) or CD8+T cells abolished the immune response against DX-treated apoptotic tumor cells in vivo. Caspase inhibition suppressed the capacity of DX-killed cells to be phagocytosed by DCs, yet had no effect on their capacity to elicit DC maturation. Freshly excised tumors became immunogenic upon DX treatment in vitro, and intratumoral inoculation of DX could trigger the regression of established tumors in immunocompetent mice. These results delineate a procedure for the generation of cancer vaccines and the stimulation of anti-neoplastic immune responses in vivo.
Collapse
Affiliation(s)
- Noelia Casares
- Centre National de la Recherche Scientifique UMR8125, Institut Gustave Roussy, F-94805 Villejuif, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Vahsen N, Candé C, Brière JJ, Bénit P, Joza N, Larochette N, Mastroberardino PG, Pequignot MO, Casares N, Lazar V, Feraud O, Debili N, Wissing S, Engelhardt S, Madeo F, Piacentini M, Penninger JM, Schägger H, Rustin P, Kroemer G. AIF deficiency compromises oxidative phosphorylation. EMBO J 2004; 23:4679-89. [PMID: 15526035 PMCID: PMC533047 DOI: 10.1038/sj.emboj.7600461] [Citation(s) in RCA: 475] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2004] [Accepted: 10/05/2004] [Indexed: 12/20/2022] Open
Abstract
Apoptosis-inducing factor (AIF) is a mitochondrial flavoprotein that, after apoptosis induction, translocates to the nucleus where it participates in apoptotic chromatinolysis. Here, we show that human or mouse cells lacking AIF as a result of homologous recombination or small interfering RNA exhibit high lactate production and enhanced dependency on glycolytic ATP generation, due to severe reduction of respiratory chain complex I activity. Although AIF itself is not a part of complex I, AIF-deficient cells exhibit a reduced content of complex I and of its components, pointing to a role of AIF in the biogenesis and/or maintenance of this polyprotein complex. Harlequin mice with reduced AIF expression due to a retroviral insertion into the AIF gene also manifest a reduced oxidative phosphorylation (OXPHOS) in the retina and in the brain, correlating with reduced expression of complex I subunits, retinal degeneration, and neuronal defects. Altogether, these data point to a role of AIF in OXPHOS and emphasize the dual role of AIF in life and death.
Collapse
Affiliation(s)
- Nicola Vahsen
- CNRS-UMR8125, Institut Gustave Roussy, Villejuif, France
| | - Céline Candé
- CNRS-UMR8125, Institut Gustave Roussy, Villejuif, France
| | | | - Paule Bénit
- INSERM U393, Service de Génétique, Hôpital Necker-Enfants Malades, France
| | - Nicholas Joza
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | | | | | | | - Noelia Casares
- CNRS-UMR8125, Institut Gustave Roussy, Villejuif, France
| | - Vladimir Lazar
- Unité de Génomique Fonctionelle, Institut Gustave Roussy, Villejuif, France
| | | | - Najet Debili
- INSERM U362, Institut Gustave Roussy, Villejuif, France
| | - Silke Wissing
- Physiologisch-chemisches Institut, Tübingen, Germany
| | | | - Frank Madeo
- Physiologisch-chemisches Institut, Tübingen, Germany
| | - Mauro Piacentini
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Josef M Penninger
- IMBA, Institute of Molecular Biotechnology of the Austrian Academy of Sciences, Vienna, Austria
| | - Hermann Schägger
- Institut für Biochemie I, Universitätsklinikum Frankfurt, Frankfurt am Main, Germany
- These authors share senior co-authorship
| | - Pierre Rustin
- INSERM U393, Service de Génétique, Hôpital Necker-Enfants Malades, France
- These authors share senior co-authorship
| | - Guido Kroemer
- CNRS-UMR8125, Institut Gustave Roussy, Villejuif, France
- These authors share senior co-authorship
| |
Collapse
|
10
|
Cherqui S, Sevin C, Hamard G, Kalatzis V, Sich M, Pequignot MO, Gogat K, Abitbol M, Broyer M, Gubler MC, Antignac C. Intralysosomal cystine accumulation in mice lacking cystinosin, the protein defective in cystinosis. Mol Cell Biol 2002; 22:7622-32. [PMID: 12370309 PMCID: PMC135682 DOI: 10.1128/mcb.22.21.7622-7632.2002] [Citation(s) in RCA: 136] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cystinosis is an autosomal recessive disorder characterized by an accumulation of intralysosomal cystine. The causative gene, CTNS, encodes cystinosin, a seven-transmembrane-domain protein, which we recently showed to be a lysosomal cystine transporter. The most severe and frequent form of cystinosis, the infantile form, appears around 6 to 12 months, with a proximal tubulopathy (de Toni-Debré-Fanconi syndrome) and ocular damage. End-stage renal failure is reached by 10 years of age. Accumulation of cystine in all tissues eventually leads to multisystemic disease. Treatment with cysteamine, which reduces the concentration of intracellular cystine, delays disease progression but has undesirable side effects. We report the first Ctns knockout mouse model generated using a promoter trap approach. We replaced the last four Ctns exons by an internal ribosome entry site-betagal-neo cassette and showed that the truncated protein was mislocalized and nonfunctional. Ctns(-/-) mice accumulated cystine in all organs tested, and cystine crystals, pathognomonic of cystinosis, were observed. Ctns(-/-) mice developed ocular changes similar to those observed in affected individuals, bone defects and behavioral anomalies. Interestingly, Ctns(-/-) mice did not develop signs of a proximal tubulopathy, or renal failure. A preliminary therapeutic trial using an oral administration of cysteamine was carried out and demonstrated the efficiency of this treatment for cystine clearance in Ctns(-/-) mice. This animal model will prove an invaluable and unique tool for testing emerging therapeutics for cystinosis.
Collapse
|
11
|
Pequignot MO, Desguerre I, Dey R, Tartari M, Zeviani M, Agostino A, Benelli C, Fouque F, Prip-Buus C, Marchant D, Abitbol M, Marsac C. New splicing-site mutations in the SURF1 gene in Leigh syndrome patients. J Biol Chem 2001; 276:15326-9. [PMID: 11279059 DOI: 10.1074/jbc.m100388200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The gene SURF1 encodes a factor involved in the biogenesis of cytochrome c oxidase, the last complex in the respiratory chain. Mutations of the SURF1 gene result in Leigh syndrome and severe cytochrome c oxidase deficiency. Analysis of seven unrelated patients with cytochrome c oxidase deficiency and typical Leigh syndrome revealed different SURF1 mutations in four of them. Only these four cases had associated demyelinating neuropathy. Three mutations were novel splicing-site mutations that lead to the excision of exon 6. Two different novel heterozygous mutations were found at the same guanine residue at the donor splice site of intron 6; one was a deletion, whereas the other was a transition [588+1G>A]. The third novel splicing-site mutation was a homozygous [516-2_516-1delAG] in intron 5. One patient only had a homozygous polymorphism in the middle of the intron 8 [835+25C>T]. Western blot analysis showed that Surf1 protein was absent in all four patients harboring mutations. Our studies confirm that the SURF1 gene is an important nuclear gene involved in the cytochrome c oxidase deficiency. We also show that Surf1 protein is not implicated in the assembly of other respiratory chain complexes or the pyruvate dehydrogenase complex.
Collapse
Affiliation(s)
- M O Pequignot
- Laboratoire CERTO, Faculté de Médecine Necker, 156 rue de Vaugirard, 75015 Paris, France
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|