DAVID GRANOVSKY

Posts Tagged ‘Intestine’

AMNIOTIC STEM CELLS HEAL INTESTINAL DISORDER

In STEM CELLS IN THE NEWS on March 27, 2013 at 9:00 am

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Amniotic stem cells heal intestinal disorder that afflicts premature babies

A new study published in GUT (An International Journal of Gastroenterology and Hepatology) has shown that amniotic fluid stem cells can reverse intestinal damage in rats caused by necrotising enterocolitis — an often fatal disorder that afflicts premature babies.

Paolo De Coppi had already proved that amniotic fluid could be reprogrammed in a similar way to how we reprogram embryonic stem cells, and without introducing potentially damaging genes to instigate the transformation (how adult cells are made pluripotent). Though not quite as versatile as the embryonic version, De Coppi showed that they could be converted into liver, bone and nerve cells.

What’s interesting about this latest study is that the stem cells calmed the intestinal inflammation, healed and reversed damage done to the gut far better than bone marrow stem cells (used in a rate control group), and in an unexpected way. After being injected, the cells travelled to the tiny villi that line the intestinal walls and absorb nutrients, where it then released an unknown substance that triggered progenitor cells to calm the inflammation and instigate tissue and villi regrowth. The team is unsure exactly how it released a growth factor to kick the progenitor cells into action, but it’s hoping further studies could clear this up — that knowledge could then be used to develop drugs that replicate the same action.

In the meantime, De Coppi says, “we hope that stem cells found in amniotic fluid will be used more widely in therapies and in research, particularly for the treatment of congenital malformations”.

Necrotising enterocolitis is common in premature babies, with inflammation rapidly leading to tissue death and a perforated intestine if antibiotics have no effect. At that point, an operation is the only option and these have a 70 percent survival rate due to related risks of surgery at such a young age, and can leave infants with a shortened intestine and trouble eating for the rest of their lives. This latest study gives hope for an injectable, non-invasive solution.

Stem cells have already been shown to have some incredible properties for regenerative medicine — most recently baboon embryonic stem cells were used to repair damaged arteries. However, due the ethical grey area embryonic experiments reside in, progress has inevitably been slower, with the first official human trials only recently beginning to take place. Stem cells derived from amniotic fluid have huge potential, but would mainly still rely on donors given the impracticalities of storing fluid from every birth. Nevertheless, according to estimates published in a 2005 study, just 150 donors would provide a match for 38 percent of the population.

De Coppi, who in 2010 made headlines when he built an 11-year-old boy a trachea replacement from his own bone marrow stem cells, is currently raising funding for his research into building rejection-free transplants from stem cells.

http://www.wired.co.uk/news/archive/2013-03/25/amniotic-fluid

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IBD PATIENTS SOON TO BE TREATED WITH STEM CELLS

In SCIENCE & STEM CELLS, STEM CELLS IN THE NEWS on March 4, 2013 at 9:02 am

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Research Supports Promise of Cell Therapy for Bowel Disease

Researchers have identified a special population of adult stem cells in bone marrow that have the natural ability to migrate to the intestine and produce intestinal cells, suggesting their potential to restore healthy tissue in patients with inflammatory bowel disease (IBD).

Up to 1 million Americans have IBD, which is characterized by frequent diarrhea and abdominal pain. IBD actually refers to two conditions — ulcerative colitis and Crohn’s disease — in which the intestines become red and swollen and develop ulcers, probably as the result of the body having an immune response to its own tissue.

While there is currently no cure for IBD, there are drug therapies aimed at reducing inflammation and preventing the immune response. Because these therapies aren’t always effective, scientists hope to use stem cells to develop an injectable cell therapy to treat IBD.  The research findings are reported online in the FASEB Journal (the journal of the Federation of American Societies for Experimental Biology) by senior researcher Graca Almeida-Porada, M.D., Ph.D., professor of regenerative medicine at Wake Forest Baptist’s Institute for Regenerative Medicine, and colleagues.

The new research complements a 2012 report by Almeida-Porada’s team that identified stem cells in cord blood that are involved in blood vessel formation and also have the ability to migrate to the intestine.  “We’ve identified two populations of human cells that migrate to the intestine — one involved in blood vessel formation and the other that can replenish intestinal cells and modulates inflammation,” said Almeida-Porada. “Our hope is that a mixture of these cells could be used as an injectable therapy to treat IBD.”

The cells would theoretically induce tissue recovery by contributing to a pool of cells within the intestine. The lining of the intestine has one of the highest cellular turnover rates in the body, with all cell types being renewed weekly from this pool of cells, located in an area of the intestine known as the crypt.  In the current study, the team used cell markers to identify a population of stem cells in human bone marrow with the highest potential to migrate to the intestine and thrive. The cells express high levels of a receptor (ephrin type B) that is involved in tissue repair and wound closure.

The cells also known to modulate inflammation were injected into fetal sheep at 55 to 62 days gestation. At 75 days post-gestation, the researchers found that most of the transplanted cells were positioned in the crypt area, replenishing the stem cells in the intestine.

“Previous studies in animals have shown that the transplantation of bone-marrow-derived cells can contribute to the regeneration of the gastrointestinal tract in IBD,” said Almeida-Porada.

http://www.wakehealth.edu

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