making muscle wasting history

Prof. George Karpati and his co-workers at McGill University in Montreal, Canada, transferred the entire gene of utrophin with a single injection of an adenovirus vector system into the tibialis anterior muscle of newborn and adult mdx mice. Afterwards, 58% of the fibers of the injected muscle in the newborn and 35% in the adult mice contained utrophin in the places underneath the membranes normally occupied by dystrophin in healthy mice. The proteins of the dystrophin-associated complex were restored for up to one year.

The new utrophin at the cell membranes prevented the necrosis (the dystrophic damage) of the injected muscle in the newborn and stopped it in the adult mdx mice. Physiological tests showed that the function of the entire treated muscle was improved. As utrophin is normally present at the nerve-muscle junctions, no immune responses appeared against the new utrophin.

However, the increased amount of utrophin in the adult mice, but not in the newborn mice, decreased with time. This is an indication that such a genetic treatment, if it could be successfully repeated in children, should be applied as early as possible in Duchenne patients.