MUSCLE stem cells have been discovered that not only make lots of muscle, but can also form other key components of muscle fibres such as connective tissue, blood vessels and nerves.
The cells, which are very rare and complicated to isolate, could one day be used to regenerate muscle in people with a range of disorders. But there鈥檚 one application that has Johnny Huard, the University of Pittsburgh researcher who found the cells, especially excited. 鈥淥ur main goal is to alleviate muscle weakness in Duchenne muscular dystrophy,鈥� he says. Duchenne is a fatal wasting disease caused by a fault in the gene for a key muscle protein called dystrophin.
Huard derived the muscle stem cells from healthy mice and injected them into the leg muscles of a strain of mice that has a disorder similar to Duchenne. Within 10 days, large amounts of the wasted muscles had regenerated鈥攗p to 20 per cent of the muscle mass was derived from the injected stem cells. 鈥淭hat鈥檚 a lot of muscle,鈥� says Huard, whose results will appear in the Journal of Cell Biology.
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There was no immune rejection and dystrophin was detected in the muscles for the first time. However, Huard has yet to determine if there was any improvement in muscle function.
Even if function does improve, Huard says, it鈥檚 too early to raise people鈥檚 hopes. The mouse disorder is not exactly the same as muscular dystrophy in people, so he is now trying to isolate the stem cells from dogs, which suffer from a condition very similar to the human disorder.