Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Silence the gene, save the cell: RNA interference as promising therapy for ALS

14.03.2005


Scientists at the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland have used RNA interference in transgenic mice to silence a mutated gene that causes inherited cases of amytrophic lateral sclerosis (ALS), substantially delaying both the onset and the progression rate of the fatal motor neuron disease. Their results will be published in the April issue of Nature Medicine, and in the journal’s advanced online publication March 13.



In addition to silencing the mutated gene that causes ALS, the EPFL researchers were able to simultaneously deliver a normal version of the gene to motor neuron cells using a single delivery mechanism. "This is the first proof of principle in the human form of a disease of the nervous system in which you can silence the gene and at the same time produce another normal form of the protein," notes Patrick Aebischer, EPFL President and a co-author of the study.

ALS is a progressive neurological disease that attacks the motor neurons controlling muscles. Although its victims retain all their mental faculties, they experience gradual paralysis and eventually lose all motor function, becoming unable to speak, swallow or breathe. Known also as Lou Gehrig’s disease, from the baseball player who succumbed to it, this harrowing disease has no cure and its pathogenesis is not very well understood.


An estimated 5,000 Americans are diagnosed with ALS every year, and most of these cases are "sporadic", with no identifiable cause. About 5-10% of ALS cases are inherited. Of these, 20% have been linked to any of more than 100 mutations in the gene that expresses the superoxide dismutase enzyme (SOD1).

These SOD1 mutations are "toxic gain-of-function mutations," meaning that the protein expressed by the mutated gene has, in addition to all its normal cellular functions, some additional function that makes it toxic to the cell. "Any mutation to the SOD1 gene is fatal to motor neuron cells," Aebischer notes. Recent research also indicates that mutant SOD1 gene expression in neighboring glial cells is also implicated in motor neuron death.

Lead author Cedric Raoul and colleagues targeted the cause of the disease by using RNA interference to silence the defective gene, preventing it from expressing the SOD1 protein.

RNA interference is part of a complex cellular housekeeping process that protects cells from invading viruses or other genetic threats. It works by interrupting messenger RNA as it transfers the genetic code for a protein from the nucleus to the site in the cell where the protein is synthesized.

To trigger RNA interference and silence a gene, short bits of double-stranded RNA are introduced in the cell, where they bind with matching sections of messenger RNA. The cell identifies the resulting messenger RNA strand as faulty and chops it up. As a result, the genetic blueprint isn’t delivered and the protein never gets made. "Gene silencing is an example of using "molecular scissors" at its most advanced level," Raoul explains.

Raoul and colleagues used RNA interference to reduce levels of mutant SOD1 protein in the spinal cords of transgenic ALS mice (mice bred to express the human SOD1 gene). Short strands of RNA that targeted multiple mutated and normal forms of the human SOD1 gene were delivered in a specially engineered lentivirus. Expression of the SOD1 protein was knocked down in the affected motor neurons and neighboring glial cells, and both the onset and the rate of progression of the disease in the treated mice were substantially reduced. In addition, the mice showed a significant improvement in neuromuscular function. "This is the first demonstration of therapeutic efficacy in vivo of RNA interference-mediated gene silencing in an ALS model," notes Raoul.

Because the normal form of the SOD1 protein may be necessary for the survival or function of adult human motor neurons, the Swiss researchers designed a gene replacement technology that allows the knock-down of all mutant SOD1 forms while permitting the expression of a normal type SOD1 protein that is resistant to RNA interference-based silencing. Both these effects are expressed long-term via delivery by a single lentiviral vector.

Aebischer is optimistic about the future of gene silencing as a potential therapy, particularly in incurable progressive neurological diseases such as ALS. "I would not be surprised to see, in the next ten years, this technology used for treating diseases of the nervous system, particularly diseases that involve toxic gain-of-function, such as inherited forms of Parkinson’s disease or Huntington’s disease," notes Aebischer. "But it’s important to note that the safety of delivering lentiviral vectors to the nervous system will have to be carefully examined prior to treating patients."

Mary Parlange | EurekAlert!
Further information:
http://www.epfl.ch

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>