June 02, 2007
Stem Cells Strengthen Urethra Muscles
Adult stem cells reduced stress urinary incontinence.
ANAHEIM, Calif., May 21 -- Women with stress urinary incontinence (SUI) treated using muscle-derived stem cell injections to strengthen their sphincter muscles experience long-term improvements in their condition, according to a study led by researchers at the University of Pittsburgh School of Medicine and Sunnybrook Health Sciences Centre in Toronto. The study, which followed patients for more than one year, suggests that the approach is safe, improves patients’ quality of life and may be an effective treatment for SUI. The findings will be presented at the Tissue Engineering and Regenerative Medicine in Urology press briefing at the annual meeting of the American Urological Association (AUA) in San Diego, and will be published in Abstract 1331 in the AUA proceedings.
The results of this study illustrate a pattern: Stem cell therapies for maladies of aging bodies look like rejuvenation therapies. The development of stem cell therapies to treat various problems will produce treatments that do rejuvenation. As long as civilization isn't destroyed by a natural disaster such as an asteroid or massive volcanic eruption the development of rejuvenation therapies is inevitable.
Someone might object and argue that this treatment has a very narrow effect on one location in the body. But these researchers are developing a rather general capability where they can supply replacement muscle cells where lack of muscle cells is the problem. Well, as we grow old our muscle cells become hobbled by damage and die. This happens in all our muscles. The ability to grow stem cells and turn them into muscle cells is a key capability needed to rejuvenate our bodies.
In the study, Dr. Carr and colleagues took biopsies of skeletal muscle tissue from eight female patients and isolated and expanded the stem cells from the tissue in culture. In an outpatient setting, the patients then received injections of the muscle-derived stem cells into the area surrounding the urethra. Each patient received an equal dose of stem cell injections using three different injection techniques – a transurethral injection with either an 8-mm or 10-mm needle or a periurethral injection.
Five of the eight women who participated in the study reported improvement in bladder control and quality of life with no serious short- or long-term adverse effects one year after the initial treatment.
A future enhancement of this treatment will be to take the muscle stem cells, treat them with gene therapies to correct accumulated DNA damage, and then grow them up for injection. Eventually scientists will even discover genetic variations that enhance muscle performance and the stem cells will get genetically engineered to form better muscle cells than we were born with.
I'm interested in how far the injected stem cells migrate from the injection site; That would dictate how many injections you'd need to achieve full coverage of skeletal muscles for regeneration. Even if it was only one injection per muscle compartment, you'd be talking many hundreds of injections. Potentially tens of thousands if the cells don't migrate very far. It would almost certainly require some kind of CNC injection system.
If we have to get at least one injection per muscle then that is about 650 injections already. Though I also found 630 for a count and the number depends on how you classify them.
Likely we'll need multiple injections into larger muscles.
We have stem cells of various types in our bones. Well, we also have 206 bones. Plus, we have assorted organs and layers.
One can imagine the need for thousands of injections in order to do stem cell updates and gene therapy.
"future enhancement of this treatment will be to take the muscle stem cells, treat them with gene therapies to correct accumulated DNA damage, and then grow them up for injection."
BTW, wouldn't it be more efficient to engineer an optimized muscle stem cell line, and then program them to be imunilogically compatable with specific patients? You could strip out all the unused DNA, and wouldn't have to worry nearly so much about interactions between the changes and many different patients' DNA.
How hard is the immunological programming versus the other progamming? Maybe you are right. I think it depends on just how many different surface proteins can cause an immunological response and how many genes control those proteins.
We'd have to replace all the incompatible genes with compatible ones.
My guess is initially the immuno-enigneering approach will be harder than just isolating some cells from your body, selecting among those cell line which has little DNA damage, then repair that cell line. Then grow up lots of stem cells from that stem cell line.
The process involves just selecting cells out of a large set of cells. Some DNA testing and automated means to grow up cells from many samples would allow selection of pretty good quality cells.
Hm, injection might not be necessary:
"In one study, Giulio Cossu, of the Stem Cell Research Institute in Milan, Italy, and his colleagues restored muscle function to mice with muscular dystrophy. The researchers injected stem cells from the blood vessels of healthy mice into leg arteries of mice with muscular dystrophy. The stem cells, which they call “mesoangioblasts,” accumulated in the diseased muscle within hours and eventually gave rise to healthy muscle tissue.
The stem cells only cross the lining of the blood vessel and enter muscle tissue if inflammation, which occurs in muscular dystrophy, is present. Researchers have found that a protein released by damaged cells can attract mesoangioblast stem cells."
If the stem cells can cross from the circulatory system, this may be a bit simpler that we think.
Note the signals sent out by inflammed muscle in those suffering from muscular dystrophy. I wonder whether old muscles send out the right signals to attract stem cells. Maybe they would if heavily exercised.