Movement Disorders, Article first published online: 24 AUG 2010, DOI: 10.1002/mds.23222
Winfried Ilg PhD1, Doris Brötz PT2, 3. Susanne Burkard PT3, Martin A. Giese PhD1, Ludger Schöls MD4,*, Matthis Synofzik MD4.
Wednesday, August 25, 2010
Tuesday, August 24, 2010
Prospects for the Use of Artificial Chromosomes and Minichromosome-Like Episomes in Gene Therapy
Journal of Biomedicine and Biotechnology, Volume 2010 (2010), Article ID 642804, 16 pages, doi:10.1155/2010/642804
Sara Pérez-Luz1,2,3 and Javier Díaz-Nido1,2,3
1Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
2Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), C/Nicolás Cabrera 1, Universidad Autónoma de Madrid, 28049 Madrid, Spain
3U-748, Area de Neurogenética, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain
OPEN ACCESS
Abstract
Artificial chromosomes and minichromosome-like episomes are large DNA molecules capable of containing whole genomic loci, and be maintained as nonintegrating, replicating molecules in proliferating human somatic cells. Authentic human artificial chromosomes are very difficult to engineer because of the difficulties associated with centromere structure, so they are not widely used for gene-therapy applications. However, OriP/EBNA1-based episomes, which they lack true centromeres, can be maintained stably in dividing cells as they bind to mitotic chromosomes and segregate into daughter cells. These episomes are more easily engineered than true human artificial chromosomes and can carry entire genes along with all their regulatory sequences. Thus, these constructs may facilitate the long-term persistence and physiological regulation of the expression of therapeutic genes, which is crucial for some gene therapy applications. In particular, they are promising vectors for gene therapy in inherited diseases that are caused by recessive mutations, for example haemophilia A and Friedreich's ataxia. Interestingly, the episome carrying the frataxin gene (deficient in Friedreich's ataxia) has been demonstrated to rescue the susceptibility to oxidative stress which is typical of fibroblasts from Friedreich's ataxia patients. This provides evidence of their potential to treat genetic diseases linked to recessive mutations through gene therapy.
FULLTEXT PDF
Sara Pérez-Luz1,2,3 and Javier Díaz-Nido1,2,3
1Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain
2Centro de Biología Molecular “Severo Ochoa” (CSIC-UAM), C/Nicolás Cabrera 1, Universidad Autónoma de Madrid, 28049 Madrid, Spain
3U-748, Area de Neurogenética, Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Spain
OPEN ACCESS
Abstract
Artificial chromosomes and minichromosome-like episomes are large DNA molecules capable of containing whole genomic loci, and be maintained as nonintegrating, replicating molecules in proliferating human somatic cells. Authentic human artificial chromosomes are very difficult to engineer because of the difficulties associated with centromere structure, so they are not widely used for gene-therapy applications. However, OriP/EBNA1-based episomes, which they lack true centromeres, can be maintained stably in dividing cells as they bind to mitotic chromosomes and segregate into daughter cells. These episomes are more easily engineered than true human artificial chromosomes and can carry entire genes along with all their regulatory sequences. Thus, these constructs may facilitate the long-term persistence and physiological regulation of the expression of therapeutic genes, which is crucial for some gene therapy applications. In particular, they are promising vectors for gene therapy in inherited diseases that are caused by recessive mutations, for example haemophilia A and Friedreich's ataxia. Interestingly, the episome carrying the frataxin gene (deficient in Friedreich's ataxia) has been demonstrated to rescue the susceptibility to oxidative stress which is typical of fibroblasts from Friedreich's ataxia patients. This provides evidence of their potential to treat genetic diseases linked to recessive mutations through gene therapy.
Section: "4.4. Gene Therapy for Friedreich’s Ataxia"
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Mitochondrial protein import: from proteomics to functional mechanisms
Nature Reviews Molecular Cell Biology 11, 655–667 (1 September 2010) | doi:10.1038/nrm2959
Oliver Schmidt , Nikolaus Pfanner & Chris Meisinger
Keywords: Mitochondria, proteins, cytosol, import pathways, protein translocases.
Oliver Schmidt , Nikolaus Pfanner & Chris Meisinger
Keywords: Mitochondria, proteins, cytosol, import pathways, protein translocases.
Sunday, August 22, 2010
Cytosolic Iron-Sulfur Cluster Assembly (CIA) System: Factors, Mechanism, and Relevance to Cellular Iron Regulation
J. Biol. Chem. 2010 285: 26745-26751. doi:10.1074/jbc.R110.122218
Anil K Sharma, Leif J Pallesen, Robert J Spang and William E Walden*
University of Illinois at Chicago, United States
KEYWORDS: Iron sulfur (FeS) cluster biogenesis, cellular iron homeostasis.
Anil K Sharma, Leif J Pallesen, Robert J Spang and William E Walden*
University of Illinois at Chicago, United States
KEYWORDS: Iron sulfur (FeS) cluster biogenesis, cellular iron homeostasis.
Friday, August 20, 2010
Expression of Human Frataxin Is Regulated by Transcription Factors SRF and TFAP2
Li K, Singh A, Crooks DR, Dai X, Cong Z, et al. 2010 . PLoS ONE 5(8): e12286. doi:10.1371/journal.pone.0012286
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Abstract
Background
Friedreich ataxia is an autosomal recessive neurodegenerative disease caused by reduced expression levels of the frataxin gene (FXN) due to expansion of triplet nucleotide GAA repeats in the first intron of FXN. Augmentation of frataxin expression levels in affected Friedreich ataxia patient tissues might substantially slow disease progression.
Methodology/Principal Findings
We utilized bioinformatic tools in conjunction with chromatin immunoprecipitation and electrophoretic mobility shift assays to identify transcription factors that influence transcription of the FXN gene. We found that the transcription factors SRF and TFAP2 bind directly to FXN promoter sequences. SRF and TFAP2 binding sequences in the FXN promoter enhanced transcription from luciferase constructs, while mutagenesis of the predicted SRF or TFAP2 binding sites significantly decreased FXN promoter activity. Further analysis demonstrated that robust SRF- and TFAP2-mediated transcriptional activity was dependent on a regulatory element, located immediately downstream of the first FXN exon. Finally, over-expression of either SRF or TFAP2 significantly increased frataxin mRNA and protein levels in HEK293 cells, and frataxin mRNA levels were also elevated in SH-SY5Y cells and in Friedreich ataxia patient lymphoblasts transfected with SRF or TFAP2.
Conclusions/Significance
We identified two transcription factors, SRF and TFAP2, as well as an intronic element encompassing EGR3-like sequence, that work together to regulate expression of the FXN gene. By providing new mechanistic insights into the molecular factors influencing frataxin expression, our results should aid in the discovery of new therapeutic targets for the treatment of Friedreich ataxia.
FULL TEXT PDF
OPEN ACCESS
Abstract
Background
Friedreich ataxia is an autosomal recessive neurodegenerative disease caused by reduced expression levels of the frataxin gene (FXN) due to expansion of triplet nucleotide GAA repeats in the first intron of FXN. Augmentation of frataxin expression levels in affected Friedreich ataxia patient tissues might substantially slow disease progression.
Methodology/Principal Findings
We utilized bioinformatic tools in conjunction with chromatin immunoprecipitation and electrophoretic mobility shift assays to identify transcription factors that influence transcription of the FXN gene. We found that the transcription factors SRF and TFAP2 bind directly to FXN promoter sequences. SRF and TFAP2 binding sequences in the FXN promoter enhanced transcription from luciferase constructs, while mutagenesis of the predicted SRF or TFAP2 binding sites significantly decreased FXN promoter activity. Further analysis demonstrated that robust SRF- and TFAP2-mediated transcriptional activity was dependent on a regulatory element, located immediately downstream of the first FXN exon. Finally, over-expression of either SRF or TFAP2 significantly increased frataxin mRNA and protein levels in HEK293 cells, and frataxin mRNA levels were also elevated in SH-SY5Y cells and in Friedreich ataxia patient lymphoblasts transfected with SRF or TFAP2.
Conclusions/Significance
We identified two transcription factors, SRF and TFAP2, as well as an intronic element encompassing EGR3-like sequence, that work together to regulate expression of the FXN gene. By providing new mechanistic insights into the molecular factors influencing frataxin expression, our results should aid in the discovery of new therapeutic targets for the treatment of Friedreich ataxia.
FULL TEXT PDF
Wednesday, August 18, 2010
H MR Spectroscopy in Friedreich's Ataxia and Ataxia with Oculomotor Apraxia Type 2.
Brain Res. 2010 Aug 13. [Epub ahead of print]
Iltis I, Hutter D, Bushara KO, Clark HB, Gross M, Eberly LE, Gomez CM, Oz G.
Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, U.S.A.
Keywords: Friedreich's ataxia (FRDA, ataxia with oculomotor apraxia type 2 (AOA2), brain metabolism, biomarker of the disease progression, Friedreich's Ataxia Rating Scale (FARS), monitor disease progression.
Iltis I, Hutter D, Bushara KO, Clark HB, Gross M, Eberly LE, Gomez CM, Oz G.
Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, U.S.A.
Keywords: Friedreich's ataxia (FRDA, ataxia with oculomotor apraxia type 2 (AOA2), brain metabolism, biomarker of the disease progression, Friedreich's Ataxia Rating Scale (FARS), monitor disease progression.
Saturday, August 14, 2010
First half report 2010 - Lundbeck
Lu AA24493 is in clinical phase II in the treatment of Friedreich's ataxia and
in clinical phase I in the treatment of acute ischaemic stroke. Ongoing studies
in both programmes are expected to be concluded in the second half of 2010.
in clinical phase I in the treatment of acute ischaemic stroke. Ongoing studies
in both programmes are expected to be concluded in the second half of 2010.
Santhera Obtains European Patent for Use of Catena®/Sovrima®
Liestal, Switzerland, August 13, 2010 - Santhera Pharmaceuticals (SIX: SANN)
announced today that the European Patent Office granted patent protection for
the use of idebenone (brand name Catena®/Sovrima®) in the treatment of Duchenne
Muscular Dystrophy and other muscular dystrophies.
announced today that the European Patent Office granted patent protection for
the use of idebenone (brand name Catena®/Sovrima®) in the treatment of Duchenne
Muscular Dystrophy and other muscular dystrophies.
Wednesday, August 11, 2010
Friedreich’s Ataxia Induced Pluripotent Stem Cells Recapitulate GAA•TTC Triplet-Repeat Instability
NCBI, Public on Jul 02, 2010
Experiment type: Expression profiling by array
Keywords: Friedreich’s ataxia (FRDA), GAA•TTC trinucleotide repeats, FXN gene, induced pluripotent stem cells (iPSCs), fibroblasts, retroviral transduction, Msh2, repeat instability.
Experiment type: Expression profiling by array
Keywords: Friedreich’s ataxia (FRDA), GAA•TTC trinucleotide repeats, FXN gene, induced pluripotent stem cells (iPSCs), fibroblasts, retroviral transduction, Msh2, repeat instability.
A Phase 3, Double-blind, Placebo-Controlled Trial of Idebenone in Friedreich Ataxia
Arch Neurol. 2010;67(8):941-947. doi:10.1001/archneurol.2010.168
David R. Lynch, MD, PhD ; Susan L. Perlman, MD ; Thomas Meier, PhD
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