US researchers have managed to slow down the progression of amyotrophic lateral sclerosis (ALS), or Lou Gehrig’s disease, in mice by using gene therapy. Dr Fred H Gage of The Salk Institute for Biological Studies in La Jolla, California, and colleagues injected mice bred to develop ALS with a gene for the hormone insulin-like growth factor 1 (IGF-1). The researchers used a virus called an adeno-associated virus (AAV) to deliver the gene as it is transported up nerve pathways to the spinal cord when injected into muscles. The mice were injected with the therapy in their hind limb and ribcage muscles when they were 60 days old and non-symptomatic. Results showed that the treatment successfully delayed the onset of ALS and extended the lifespan of the animals. Those not treated with the gene therapy developed ALS at 91 days, and had a lifespan of just 160 days. In comparison, the treated animals did not develop the disease until 122 days and lived 37 days longer on average. When the scientists treated mice after the onset of the disease &endash; which is more likely to be the case in humans &endash; the treatment increased lifespan by an average of 22 days. Furthermore, the treated animals also maintained function, body weight, and muscle mass for longer. A clinical trial is now being designed to test the treatment in humans.
SOURCE/REFERENCE: Science 2003;301:839-843.
