Replacing a Damaged Stem Cell Population
You might recall that a combination of chemotherapy and introduction of new immune system stem cells has been used to successfully "reboot" a damaged immune system in a number of different early trials, thereby curing an autoimmune disease. Judging from this research I noticed today, the strategy seems to work for damaged muscle stem cell populations as well:
An experimental procedure that dramatically strengthens stem cells' ability to regenerate damaged tissue could offer new hope to sufferers of muscle-wasting diseases such as myopathy and muscular dystrophy, according to researchers from the University of New South Wales (UNSW). The world-first procedure has been successfully used to regrow muscles in a mouse model, but it could be applied to all tissue-based illnesses in humans such as in the liver, pancreas or brain, the researchers say.The research team, which is based at UNSW and formerly from Sydney's Westmead Children's Hospital, adapted a technique currently being trialled in bone marrow transplantation. Adult stem cells are given a gene that makes them resistant to chemotherapy, which is used to clean out damaged cells and allow the new stem cells to take hold.
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"The beauty of this technique is that chemotherapy makes space for stem cells coming into muscle and also gives the stem cells an advantage over the locals. It's the first strategy that gives the good guys the edge in the battle to cure sick tissues,"
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"In muscle, most stem cells die in the first hour or are present in such low numbers that they are not much help," Professor Gunning said. "Until now, the new healthy cells had no advantage over the existing damaged tissue and were getting out-competed.
Destroy the old and replace with the new: this approach to regeneration is in its infancy, but it holds a great deal of promise for dealing with the damage of aging in stem cell populations. All development is focused on specific diseases at the moment - a situation forced upon us by regulatory bodies who deny approval for therapies for aging - but the technology platforms produced can then be applied to age-related damage in a more enlightened time or place.
The chemotherapy is the ugly part of the equation for the moment, a deeply unpleasant procedure that no right-minded person would ever undertake without good cause. Fortunately, the development of methods for killing specific cell populations with few or no side effects is also advancing rapidly. One can evisage a future not so many decades away in which our stem cell populations are routinely destroyed and replaced every thirty years or so to eliminate accumulated damage that reduces their effectiveness.