Silencing of frataxin gene expression triggers p53-dependent apoptosis in human neuron-like cells

Hum. Mol. Genet. (2011) doi: 10.1093/hmg/ddr187

Gloria M. Palomo 1,2, Toñi Cerrato 1,2, Ricardo Gargini1 and Javier Díaz-Nido 1,2

1 Departamento de Biología Molecular and Centro de Biología Molecular “Severo Ochoa” (UAM-CSIC), C/ Nicolás Cabrera, 1. Campus de Cantoblanco. Universidad Autónoma de Madrid. 28049 Madrid, Spain
2 CIBER de Enfermedades Raras (CIBERER). 28049 Madrid, Spain

Keywords: Friedreich’s ataxia, frataxin, neuronal cells, lentiviral vectors, minigenes, frataxin-specific shRNAs, human neuroblastoma SH-SY5Y cells, p53, PUMA, Bax, caspase-3, autophagy, useful cell model, neurodegeneration.

European regulation on orphan medicinal products: 10 years of experience and future perspectives

Nature Reviews Drug Discovery 10, 341-349 (May 2011) | doi:10.1038/nrd3445

The Committee for Orphan Medicinal Products and the European Medicines Agency. Scientific Secretariat ¹

  

Keywords: orphan medicinal products,  European Union,  rare conditions,  orphan drug designations, Committee for Orphan Medicinal Products (COMP),  marketing authorization in Europe.

Special issue of Nature Reviews on Gene-Based Therapies

State-of-the-art gene-based therapies: the road ahead
Nature Reviews Genetics 12, 316-328 (May 2011) | doi:10.1038/nrg2971

(If you want to see some full texts in Nature you can register for free!)

Los vectores herpesvirales portadores de genes completos aseguran la persistencia de la expresión génica a largo plazo en ensayos de terapia génica en modelos animales.

Los vectores herpesvirales portadores de genes completos aseguran la persistencia de la expresión génica a largo plazo en ensayos de terapia génica en modelos animales.

Algunas enfermedades hereditarias están causadas por mutaciones, denominadas “recesivas”, que causan una menor producción de una proteína o la producción de una proteína defectuosa, incapaz de realizar correctamente su función. La terapia génica pretende curar este tipo de enfermedades mediante la introducción de los genes “sanos” que así pueden sustituir la función de los genes “defectuosos”. Para introducir dichos genes sanos en las células afectadas por la enfermedad se necesitan vehículos adecuados, los denominados “vectores”, que, en la mayoría de los casos son virus desprovistos de sus componentes más patogénicos.

El éxito de este tipo de terapia génica depende de una adecuada distribución del gen sano a un número suficiente de células afectadas así como de asegurar la persistencia de la expresión del gen “sano” en estas células. Esto último ha resultado ser particularmente más difícil de lo que en principio cabía esperar. Así pues, en numerosas ocasiones, el gen “sano” que se había introducido en una célula, al cabo del tiempo, se quedaba “silencioso”, es decir, dejaba de dar las instrucciones para la correcta producción de la proteína, con lo que la enfermedad nuevamente regresaba. Se cree que este “silenciamiento” puede deberse a la utilización de una serie de elementos “artificiales”: en primer lugar, no se utilizaba el gen de verdad sino una versión simplificada del mismo, el llamado cDNA, que contiene la información codificante de la proteína pero carece de muchos elementos requeridos para la regulación de su producción, y, en segundo lugar, se utilizaba un “promotor” de origen viral para asegurar la expresión de dicho gen. Parece ser que en el organismo, al cabo del tiempo, estos elementos son de alguna manera reconocidos como “extraños” y se produce su “silenciamiento”. Como alternativa a la utilización de estos elementos cabe recurrir a la versión natural del gen, en toda su amplitud. Esto es técnicamente más complicado, ya que los genes son normalmente muy grandes, y no caben en la mayoría de los vectores virales que son utilizados normalmente en los ensayos de terapia génica (como adenovirus, retrovirus y lentivirus). Una excepción interesante son los vectores herpesvirales, derivados del virus herpes simplex (HSV-1), capaces de acomodar hasta 150 kb de material genético.

Los grupos de Javier Diaz-Nido y Filip Lim, de la Universidad Autónoma de Madrid, en colaboración con el grupo de Richard Wade-Martins, de la Universidad de Oxford en el Reino Unido, hemos estado explorando la posibilidad de utilizar este tipo de vectores herpesvirales para la terapia génica de la ataxia de Friedreich (una enfermedad causada por la deficiencia de una proteína denominada frataxina, y que se caracteriza por la degeneración de ciertas neuronas en el sistema nervioso central, así como por otras alteraciones en el corazón y en el páncreas).

En un estudio publicado en 2007 demostramos que un vector herpesviral portador del gen completo de la frataxina era capaz de suplir las deficiencias funcionales encontradas en las células de la piel de los pacientes con ataxia de Friedreich (1).

Ahora, en un trabajo que se acaba de publicar “online” en la revista “Gene Therapy” (2) hemos podido comprobar que los vectores portadores del gen completo de la frataxina permiten una expresión persistente “in vivo” después de ser inyectados en el cerebelo de ratones. Estos resultados refuerzan la hipótesis de que los vectores portadores de genes completos no son silenciados y, en consecuencia, pueden ser muy útiles para una terapia génica a largo plazo. Otra ventaja de este tipo de vectores es que persisten como episomas estables en los núcleos de las células, no integrándose en ningún cromosoma, de manera que no causan alteraciones en el genoma de dichas células (a diferencia de lo que sucede con otros vectores). A la vista de estos datos, consideramos que los vectores herpesvirales portadores de genes completos pueden ser una herramienta muy segura y eficaz para la terapia de las enfermedades hereditarias causadas por mutaciones recesivas (como la ataxia de Friedreich).


1.- Gomez-Sebastian S, Gimenez-Cassina A, Diaz-Nido J, Lim F, Wade-Martins R.
Infectious delivery and expression of a 135 kb human FRDA genomic DNA locus complements Friedreich's ataxia deficiency in human cells.
Mol Ther. 2007 Feb;15(2):248-54.
http://www.ncbi.nlm.nih.gov/pubmed/17235301
http://www.nature.com/mt/journal/v15/n2/full/6300021a.html

2.- Gimenez-Cassina A, Wade-Martins R, Gomez-Sebastian S, Corona JC, Lim F, Diaz-Nido J.
Infectious delivery and long-term persistence of transgene expression in the brain by a 135-kb iBAC-FXN genomic DNA expression vector.
Gene Ther. 2011 Apr 14. doi:10.1038/gt.2011.45 [Epub ahead of print]
http://www.ncbi.nlm.nih.gov/pubmed/21490681
http://www.nature.com/gt/journal/vaop/ncurrent/full/gt201145a.html

Herpes viral vectors carrying complete genes ensure long-term gene expression persistence in animal models of gene therapy trials.

Press release: Herpes viral vectors carrying complete genes ensure long-term gene expression persistence in animal models of gene therapy trials.

Some hereditary diseases are caused by "recessive" mutations which cause either a decrease in the amount of a protein or the production of a defective protein, which is unable to properly perform its function. Gene therapy aims to cure such diseases through the introduction of "healthy" genes allowing the functional replacement of the "defective" genes. In order to introduce such healthy genes into the cells affected by the disease, it is necessary to use appropriate carriers, known as "vectors", which, in most cases are viruses devoid of their more pathogenic components.

The success of this type of gene therapy depends on both the proper distribution of the healthy gene to a sufficient number of affected cells and the persistence of the expression of the "healthy" gene in these cells. To ensure a long-term expression of the “healthy” gene has been a goal more difficult to attain than was anticipated. Thus, on many occasions, the "healthy" gene that had been introduced into a cell, as time went by, became "silent", i.e., it failed to give the instructions for the proper production of the protein, so the disease returned again. It is believed that this "silencing" may be due to the use of a number of "artificial" elements: first, the complete gene was not really used but a simplified version, the so-called cDNA, which contains the protein-coding information but lacks many elements required for the regulation of its production, and, second, a "promoter" of viral origin was used to ensure the expression of this gene. It seems that in the body, over time, these elements are in some way recognized as "foreign” and its “silencing” is triggered. As an alternative to the use of these elements, one could resort to the natural version of the gene, in all its length. This is technically more complicated because the genes are normally very large and do not fit into most viral vectors which are normally used in gene therapy trials (such as adenoviruses , retroviruses and lentiviruses). An interesting exception are herpes viral vectors, derived from herpes virus simplex (HSV-1), which are capable of accommodating up to 150 kb of genetic material.
Javier Diaz-Nido and Filip Lim Groups , at the Universidad Autónoma de Madrid in Spain, in collaboration with the Group of Richard Wade-Martins, of the University of Oxford in the United Kingdom, have been exploring the possibility of using this type of Herpes viral vectors for Friedreich's ataxia gene therapy (a disease caused by the deficiency of one protein called frataxin, and that is characterized by the degeneration of certain neurons in the central and peripheral nervous systems, as well as other alterations in the heart and the pancreas).

In a paper published in 2007 they showed that a herpes viral vector carrying the complete frataxin gene was able to make up for the functional deficiencies that were found in cultured skin cells of patients with Friedreich's ataxia (1).

Now, in a paper just published "online" in the "Gene Therapy" magazine (2) they have been able to demonstrate that vectors carrying the full frataxin gene allow a persistent expression "in vivo" after being injected into the mouse cerebellum. These results reinforce the view that vectors carrying complete genes are not silenced and may therefore be very useful for long term gene therapy. Another advantage of this type of herpes viral vectors is that they persist as stable “episomes” in the nuclei of cells, not integrated into any chromosome, and so they do not cause any alterations in the genome of these cells (unlike what happens with other vectors). Furthermore, herpes viral vectors are well known for their effective targeting of neuronal cells. In view of these data, it appears that herpes viral vectors carrying complete genes may be a safe and effective tool for the therapy of neurological hereditary diseases which are caused by recessive mutations (such as Friedreich's ataxia).

1.-Gomez-Sebastian S, Gimenez-Cassina A, Diaz-Nido J, Lim F, Wade-Martins R.
Infectious delivery and expression of 135 KB FRDA human genomic DNA locus complements Friedreich's ataxia deficiency in human cells.
MOL Ther. 2007 Feb; 15 (2): 248-54.
http://www.ncbi.NLM.NIH.gov/PubMed/17235301
http://www.nature.com/MT/journal/V15/N2/full/6300021a.html
2.-Gimenez-Cassina A, Wade-Martins R, Gomez-Sebastian S, Corona JC, Lim F, Diaz-Nido J.
Infectious delivery and long-term persistence of transgene expression in the brain by a 135-kb iBAC-FXN genomic DNA expression vector.
Gene Ther. 2011 Apr 14. DOI:10.1038/gt.2011.45 [Epub ahead of print]
http://www.ncbi.NLM.NIH.gov/PubMed/21490681
http://www.nature.com/gt/journal/vaop/ncurrent/full/gt201145a.html

Mitochondrial aconitase knockdown attenuates paraquat-induced dopaminergic cell death via decreased cellular metabolism and release of iron and H2O2*

Journal of Neurochemistry, 2011, DOI: 10.1111/j.1471-4159.2011.07290.x Accepted Article (Accepted, unedited articles published online for future issues)

David Cantu 1,3, Ruth E. Fulton 2, Derek A. Drechsel 2, Manisha Patel 1,2

1 Graduate Program in Neuroscience, 2 Department of Pharmaceutical Sciences, University of Colorado, 3 Department of Neuroscience, Tufts University School of Medicine

Keywords: mitochondrial aconitase, oxidative stress, paraquat, neurotoxicity, hydrogen peroxide, iron, cellular metabolism

Compositions And Methods For Treatment Of Mitochondrial Diseases Patent 7915233

Patent 7915233, Mar.,29, 2011

In page 10 :

An Open Label Clinical Pilot Study of Resveratrol as Treatment for Friedreich Ataxia

Sponsor: Murdoch Childrens Research Institute
Collaborator: Friedreich Ataxia Research Alliance
Principal Investigator: Martin Delatycki, MBBS PhD, Murdoch Childrens Research Institute
ClinicalTrials.gov Identifier: NCT01339884


"The purpose of this study is to determine the effect of two doses of resveratrol taken for a 12 week period, on frataxin levels in individuals with Friedreich ataxia. This study will also measure the effect of resveratrol on markers of oxidative stress, clinical measures of ataxia, and cardiac parameters."

Excellent in-depth explanation of Friedreich Ataxia for all public

In the CAFA - Claude St-Jean Foundation website can find this diaporama where Dr. Jacques P. Tremblay, Ph.D., professor in the Department of Molecular Medicine of Laval University in Quebec and main investigator at the Research Centre of Quebec city (CHUL) makes an excellent explanation of the genetic and molecular basis of disease, in addition to a review of current major research directions.
It is difficult for an expert explain biological mechanisms as a layman, but Dr Tremblay gets a high-level explanation that can be understood by everyone without having much knowledge in life sciences.

Download the diaporama (20 Mb)

Spinocerebellar degenerations.

Handb Clin Neurol. 2011;100:113-40.

Perlman SL.

Keywords: spinocerebellar ataxias (SCA), cerebellum, hyperkinetic movements, dominant ataxias, recessive ataxias, ataxia telangiectasia, Friedreich's ataxia, Fragile X tremor-ataxia syndrome (FXTAS), multiple-system atrophy, presence of a secondary factor.

A Boolean probabilistic model of metabolic adaptation to oxygen in relation to iron homeostasis and oxidative stress

BMC Systems Biology 2011, 5:51doi:10.1186/1752-0509-5-51

Fiona Achcar, Jean-Michel Camadro and Denis Mestivier

Interesting tool, could be helpful to understand better the role of frataxin in the iron homeostasis in Friedreich's ataxia. It could also provide some light to try to explain the great individual differences between genotype - phenotype.

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Sirt1 acts in association with PPARα to protect the heart from hypertrophy, metabolic dysregulation, and inflammation

Cardiovasc Res (2011) 90 (2): 276-284. doi: 10.1093/cvr/cvq376

Ana Planavila1,2,*, Roser Iglesias1,2, Marta Giralt1,2 and Francesc Villarroya1,2

1Departament de Bioquímica i Biologia Molecular, Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Avda Diagonal 645, Barcelona E-08028, Spain
2CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Barcelona, Spain

"Collectively, these findings reveal a major involvement of the Sirt1–PPARα interaction in the protective role of Sirt1 against cardiac hypertrophy."

Friedreich's ataxia: Past, present and future

doi:10.1016/j.brainresrev.2011.04.001

Daniele Marmolino,
Laboratoire de Neurologie experimentale, Universite Libre de Bruxeles (ULB), Route de Lennik 808, Campus Erasme - 1070 Bruxelles, Belgium

Keywords: Friedreich's ataxia; Frataxin; GAA; Iron; Fe-S clusters; Oxidative stress; FRDA pathogenesis; frataxin function; new treatments; animal and cellular models.

Project title: Characterising gait and upper limb disorder in Friedreich ataxia

Monash University will launch a new study about Friedreich's ataxia

"This project will enable both clinical and quantified gait and upper limb kinematic assessment and may provide a sensitive measure of functional change in FRDA against which the efficacy of novel interventions can be tested down the track".

Infectious delivery and long-term persistence of transgene expression in the brain by a 135-kb iBAC-FXN genomic DNA expression vector.

Gene Therapy, 14 April 2011; doi:10.1038/gt.2011.45.

Gimenez-Cassina A, Wade-Martins R, Gomez-Sebastian S, Corona JC, Lim F, Diaz-Nido J.

Department of Molecular Neurobiology, Centro de Biología Molecular Severo Ochoa, Cantoblanco, Spain.

Keywords: FRDA, gene-based therapies, long-term persistent transgene expression, entire 135 kb FXN genomic DNA locus, bacterial artificial chromosome (iBAC), herpes simplex virus type 1 (HSV-1), -based vector.

Intellect Neurosciences Files Orphan Drug Application in the United States for Its Clinical Candidate OX1 for the Treatment of Friedreich's Ataxia

NEW YORK, April 12, 2011 (GLOBE NEWSWIRE) -- Intellect Neurosciences, Inc. announced today that it has filed an orphan drug application with the Office of Orphan Products Development of the United States Food and Drug Administration (FDA) to have Orphan Drug Designation granted to its clinical stage drug candidate, OX1 (OXIGON™) for the treatment of Friedreich's Ataxia ("FA").

Mitochondria as a Therapeutic Target for Aging and Neurodegenerative Diseases

Curr Alzheimer Res. 2011 Apr 6.

Reddy PH, Reddy TP.
Neurogenetics Laboratory, Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University

Keywors: Mitochondria, postmortem brain studies, clinical studies, aging, neurodegenerative diseases, phosphorylation, mitochondrial DNA defects, mitochondrial fragmentation, decreased mitochondrial fusion.

New Method Delivers Drug to the Brain

Deliver complex drug into the the CNS is a challenge, the CNS is strongly protected by the BBB, and many substances with therapeutic high potential, frataxin, or even gene therapy, are not useful if they can not reach their therapeutic targets. It is very important to have methods to achieve this goal.

New Method Delivers Alzheimer’s Drug to the Brain
ScienceDaily (Apr. 5, 2011) — Oxford University scientists have developed a new method for delivering complex drugs directly to the brain, a necessary step for treating diseases like Alzheimer's, Parkinson's, Motor Neuron Disease and Muscular Dystrophy. read more...

Original paper: Delivery of siRNA to the mouse brain by systemic injection of targeted exosomes., Nature Biotechnology, 2011; DOI: 10.1038/nbt.1807
Lydia Alvarez-Erviti, Yiqi Seow, HaiFang Yin, Corinne Betts, Samira Lakhal & Matthew J A Wood.
Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.

Mitochondria regulate autophagy by conserved signalling pathways

The EMBO Journal advance online publication 5 April 2011; doi:10.1038/emboj.2011.104

Martin Graef and Jodi Nunnari,
Department of Molecular and Cellular Biology, Davis University of California, USA

Keywords: autophagy regulation, mitochondria, protein kinase A, TOR, cellular homeostasis, mitochondrial respiratory deficiency, autophagy gene induction, neurodegeneration.

Modern Surgery For Scoliosis Has Good Long-Term Outcomes

Medical News Today, Article Date: 05 Apr 2011,

Teenagers who undergo spine fusion for scoliosis using the newest surgical techniques can expect to be doing well 10 years after surgery, according to a Hospital for Special Surgery study published online ahead of print in the TK issue of the journal Spine. Read more...

Could thiazolidinediones increase the risk of heart failure in Friedreich's ataxia patients?

Movement Disorders, 26: n/a. doi: 10.1002/mds.23711

García-Giménez, J. L., Sanchis-Gomar, F. and Pallardó, F. V.

CIBERER, Biomedical Network Research Centre on Rare Diseases, Valencia, Spain
Department of Physiology, Faculty of Medicine, University of Valencia, Valencia, Spain
Fundación del Hospital Clínico Universitario de Valencia. FIHCUV-INCLIVA, Valencia, Spain

Keywords: Friedreich's ataxia; rare disease; neurological symptoms; hypertrophic cardiomyopathy; rosiglitazone; pioglitazone; heart failure; peroxisome proliferator-activated receptor-gamma coactivator-1α.

Patient's Own Cells May Hold Therapeutic Promise After Reprogramming, Gene Correction

ScienceDaily (Apr. 4, 2011) — Scientists from the Morgridge Institute for Research, the University of Wisconsin-Madison, the University of California and the WiCell Research Institute moved gene therapy one step closer to clinical reality by determining that the process of correcting a genetic defect does not substantially increase the number of potentially cancer-causing mutations in induced pluripotent stem cells.

Read more

Younger Cardiac Patients Benefit From Hypothermia Therapy

Medical News Today, 04 Apr 2011

Young adult patients with genetic heart diseases, such as hypertrophic cardiomyopathy (HCM), substantially benefitted from therapeutic hypothermia, which could further extend the role for this treatment strategy in new patient populations. read more....
(Source: Minneapolis Heart Institute Foundation)

MHC Mismatch Inhibits Neurogenesis and Neuron Maturation in Stem Cell Allografts

Chen Z, Phillips LK, Gould E, Campisi J, Lee SW, et al. 2011 MHC Mismatch Inhibits Neurogenesis and Neuron Maturation in Stem Cell Allografts. PLoS ONE 6(3): e14787. doi:10.1371/journal.pone.0014787

The role of histocompatibility and immune recognition in stem cell transplant therapy has been controversial, with many reports arguing that undifferentiated stem cells are protected from immune recognition due to the absence of major histocompatibility complex (MHC) markers. This argument is even more persuasive in transplantation into the central nervous system (CNS) where the graft rejection response is minimal.

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Efficient mining of haplotype patterns for linkage disequilibrium mapping.

J Bioinform Comput Biol. 2010, Volume: 8, Supplementary Issue 1(2010) pp. 127-146 DOI: 10.1142/S0219720010005142

Lin L, Wong L, Leong TY, Lai PS (*).
School of Computing, National University of Singapore, Singapore.
(*) Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore

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3.2. Friedreich ataxia
Friedreich ataxia is an autosomal recessive degenerative disease that involves the
central and peripheral nervous system and the heart. The friedreich ataxia dataset
was first reported by Liu et al. for linkage disequilibrium mapping. This dataset
contains 58 disease haplotypes and 69 control haplotypes with 12 microsatellite
markers. The gene is located between the fifth and sixth markers, approximately
9.8125cM away from the leftmost marker. The total region size in this study
is 15 cM.
.../...

Mitochondrial iron trafficking and the integration of iron metabolism between the mitochondrion and cytosol

This presentation is interesting because makes a short review and shows an overview of the various current theories on the possible functions of frataxin and its relationship with the FA