PEOPLE who suffer from the embarrassing problem of urinary incontinence could
one day be cured using stem cells taken from their muscles. The cells would be
injected into their bladders to strengthen the muscles there and restore
control.
The treatment has already been successfully tested on rats, researchers told
a meeting of the American Urological Association this week. 鈥淚t works very well.
It could make a dramatic impact,鈥� says Michael Chancellor, a urologist at the
University of Pittsburgh. 鈥淲e hope it will be in clinical trials within a
year.
In the US alone, 13 million people suffer from urinary incontinence, and the
numbers are rising as the population ages. In total, sufferers spend $16
billion a year trying to manage the problem, Chancellor says.
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Incontinence is usually caused by either a weak sphincter muscle that allows
urine to leak out, or a weak bladder that is unable to empty completely. The
researchers thought that stem cells鈥攑recursor cells that give rise to
specialised tissues鈥攃ould overcome the problem by forming new muscle
tissue.
To find out, they first used cold probes to damage the sphincters and
bladders of rats. Next, they isolated stem cells from the muscles of the rats,
altered them to carry a marker gene and grew them in culture. Then they injected
them into the damaged muscles.
Within 15 days, the stem cells had been incorporated into the damaged
muscles, differentiating to form both skeletal muscle fibres, which are under
voluntary control, and smooth muscle cells, which are controlled by the
autonomic nervous system. Tests showed that the muscles had regained about 80
per cent of their original strength, compared with just 10 per cent for muscle
that received no stem cells.
鈥淚 think it鈥檚 exciting work. I think it shows that the field of stem cells
has practical clinical applications,鈥� says Anthony Atala of Harvard Medical
School, who has used tissue engineering to create entire bladders. 鈥淯sing stem
cells to try to regenerate normal tissue is a very nice strategy.鈥�
The University of Pittsburgh is setting up a private company to bring the
therapy to market, Chancellor says. Discussions are under way with the Food and
Drug Administration to begin human trials, probably within two years.