A growth-stimulating gene treatment can dramatically improve the symptoms of mice with amytrophic lateral sclerosis (ALS), Belgian and UK researchers report. Scientists at the biotech firm Oxford BioMedica and the Flanders Interuniversity Institute for Biotechnology (VIB) found that a single injection of a therapeutic gene increased the life expectancy of mice with ALS by a third.
The treatment did not appear to cause any toxic side effects, say the team, who published their findings in Nature. Also, the treatment was effective even if the scientists waited until the mice showed signs of paralysis before injecting the gene. The researchers stress that their work is at an early stage, but conclude that their approach may have potential as a 'safe and practical treatment for many of the movement problems seen in humans with ALS'.
ALS is a progressive, incurable paralysis, a result of gradual damage to motor neurons: nerve cells in the brain and spine that control movement. It affects around one in 20,000 people, including the UK astrophysicist Stephen Hawking. Most cases of ALS are not inherited, and have no known cause, but a small proportion are caused by alterations in a gene called SOD1.
In the latest study, the scientists used mice bred to overproduce the SOD1 gene, which triggers the symptoms of ALS. They then injected a gene called VEGF into various different muscles, and found that it slowed the progression of ALS by 30 per cent. VEGF makes a protein called vascular endothelial growth factor, which controls the growth of new blood vessels, and also helps nerve cells to survive in stressful circumstances. Previous research showed that people with variations in the VEGF gene are at increased risk of developing ALS.
Brian Dickie, of the UK's MND Association, welcomed the research, saying that it reflected current optimism that gene therapy represents a 'viable strategy for the treatment of ALS and other neurodegenerative diseases'.