Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New gene transfer strategy shows promise for limb girdle and other muscular dystrophies

09.07.2012
The challenge of treating patients with genetic disorders in which a single mutated gene is simply too large to be replaced using traditional gene therapy techniques may soon be a thing of the past.

A Nationwide Children's Hospital study describes a new gene therapy approach capable of delivering full-length versions of large genes and improving skeletal muscle function. The strategy may hold new hope for treating dysferlinopathies and other muscular dystrophies.

A group of untreatable muscle disorders known as dysferlinopathies are caused by mutations in the dysferlin gene. Patients with these disorders, including limb girdle muscular dystrophy type 2B, are typically diagnosed in their early twenties. Approximately one-third will become wheelchair dependent by their mid-30s.

Gene therapy using adeno-associated virus (AAV) to deliver genes to cells has been pursued as an option for some patients with muscular dystrophy. However, AAV's packaging limitations have served as obstacles in using gene therapy to deliver large genes like dysferlin. Scientists in the past have attempted to work around AAV's packaging limitations by inserting a small version of large genes into the viral vector to induce gene expression. Some have also used more than one viral vector at a time to deliver a large gene. However, micro and mini versions of large genes don't always have the power of full-length gene expression and an increased viral load can lead to negative side effects.

"We have had success in the clinic using AAV gene therapy with limb girdle muscular dystrophy type 2D, which is caused by mutations in the alpha-sarcoglycan gene," said Louise Rodino-Klapac, PhD, principal investigator in the Center for Gene Therapy at The Research Institute of Nationwide Children's Hospital. "However, the dysferlin gene is very large, about six times larger than the alpha-sarcoglycan gene and can't fit into a traditional AAV vector."

A 2008 study identified AAV5, an AAV serotype that could package large transcripts. "This made us wonder whether it could be used for gene replacement requiring inserts as large as the dysferlin gene," said Dr. Rodino-Klapac.

In their 2012 study appearing in PLoS ONE, Dr. Rodino-Klapac's team used AAV5 to package a full-length, intact dysferlin gene and directly deliver it to the diaphragm of dysferlin-deficient mice. They also injected the leg muscles of dysferlin-deficient mice using both intramuscular and vascular approaches to further evaluate whether the gene delivery could improve skeletal muscle function.

They found that both the intravascular and intramuscular delivery approaches led to full-length, intact dysferlin gene expression in the leg and diaphragm muscle cells of the mice. More importantly, they saw that the newly-restored dysferlin repaired membrane deficits previously seen in the dysferlin-deficient mice.

"Our findings demonstrate highly favorable results with full restoration of dysferlin without compromise in function," said Dr. Rodino-Klapac. "With regard to neuromuscular diseases, these studies provide new perspective for conditions caused by mutations of large genes. Duchenne muscular dystrophy is the most common severe childhood muscular dystrophy and would seem to benefit from expression of the larger transcripts than mini- and micro-dystrophins that only partially restore physiologic function in mouse models of the disease."

Dr. Rodino-Klapac and her team are currently defining a path for a dysferlin clinical gene therapy trial. "We have shown that AAV5-dysferlin delivery is a very promising therapeutic approach that could restore functional deficits in dysferlinopathy patients," she says.

Grose WE, Clark KR, Griffin D, Malik V, Shontz KM, Montgomery CL, Lewis S, Brown RH Jr, Janssen PM, Mendell JR, Rodino-Klapac LR. Homologous Recombination Mediates Functional Recovery of Dysferlin Deficiency following AAV5 Gene Transfer. PLoS One. 2012;7(6):e39233. Epub 2012 Jun 15.

For more information on the Center for Gene Therapy, visit http://www.nationwidechildrens.org/center-for-gene-therapy
For more information on The Research Institute, visit http://www.nationwidechildrens.org/pediatric-research

For more information on Dr. Louise Rodino-Klapac, visit http://www.nationwidechildrens.org/louise-rodino-klapac

Erin Pope | EurekAlert!
Further information:
http://www.nationwidechildrens.org

More articles from Life Sciences:

nachricht Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel

nachricht Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Powerful IT security for the car of the future – research alliance develops new approaches

The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.

Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...

Im Focus: Molecular switch will facilitate the development of pioneering electro-optical devices

A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.

The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

In focus: Climate adapted plants

25.05.2018 | Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

 
Latest News

In focus: Climate adapted plants

25.05.2018 | Event News

Flow probes from the 3D printer

25.05.2018 | Machine Engineering

Less is more? Gene switch for healthy aging found

25.05.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>