Featured Research

from universities, journals, and other organizations

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

Date:
July 9, 2012
Source:
Nationwide Children's Hospital
Summary:
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 new 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.

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.

Related Articles


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.


Story Source:

The above story is based on materials provided by Nationwide Children's Hospital. Note: Materials may be edited for content and length.


Journal Reference:

  1. William E. Grose, K. Reed Clark, Danielle Griffin, Vinod Malik, Kimberly M. Shontz, Chrystal L. Montgomery, Sarah Lewis, Robert H. Brown, Paul M. L. Janssen, Jerry R. Mendell, Louise R. Rodino-Klapac. Homologous Recombination Mediates Functional Recovery of Dysferlin Deficiency following AAV5 Gene Transfer. PLoS ONE, 2012; 7 (6): e39233 DOI: 10.1371/journal.pone.0039233

Cite This Page:

Nationwide Children's Hospital. "New gene transfer strategy shows promise for limb girdle and other muscular dystrophies." ScienceDaily. ScienceDaily, 9 July 2012. <www.sciencedaily.com/releases/2012/07/120709093223.htm>.
Nationwide Children's Hospital. (2012, July 9). New gene transfer strategy shows promise for limb girdle and other muscular dystrophies. ScienceDaily. Retrieved April 18, 2015 from www.sciencedaily.com/releases/2012/07/120709093223.htm
Nationwide Children's Hospital. "New gene transfer strategy shows promise for limb girdle and other muscular dystrophies." ScienceDaily. www.sciencedaily.com/releases/2012/07/120709093223.htm (accessed April 18, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, April 18, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Our Love Of Puppy Dog Eyes Explained By Science

Our Love Of Puppy Dog Eyes Explained By Science

Newsy (Apr. 17, 2015) Researchers found a spike in oxytocin occurs in both humans and dogs when they gaze into each other&apos;s eyes. Video provided by Newsy
Powered by NewsLook.com
Scientists Find Link Between Gestational Diabetes And Autism

Scientists Find Link Between Gestational Diabetes And Autism

Newsy (Apr. 17, 2015) Researchers who analyzed data from over 300,000 kids and their mothers say they&apos;ve found a link between gestational diabetes and autism. Video provided by Newsy
Powered by NewsLook.com
Video Messages Help Reassure Dementia Patients

Video Messages Help Reassure Dementia Patients

AP (Apr. 17, 2015) Family members are prerecording messages as part of a unique pilot program at the Hebrew Home in New York. The videos are trying to help victims of Alzheimer&apos;s disease and other forms of dementia break through the morning fog of forgetfulness. (April 17) Video provided by AP
Powered by NewsLook.com
Boy or Girl? Intersex Awareness Is on the Rise

Boy or Girl? Intersex Awareness Is on the Rise

AP (Apr. 17, 2015) At least 1 in 5,000 U.S. babies are born each year with intersex conditions _ ambiguous genitals because of genetic glitches or hormone problems. Secrecy and surgery are common. But some doctors and activists are trying to change things. (April 17) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins