A University of Utah Nobel laureate has warned that stem cell therapy is a complex procedure as a single organ may contain more than one type of adult stem cell.
Geneticist Mario Capecchi, a winner of the 2007 Nobel Prize in Physiology or Medicine, believes that his finding suggests that it might not be easy to utilise adult stem cell transplants to replace damaged tissues as a treatment for disease.
Working with his colleague Eugenio Sangiorgi in his own laboratory, Capecchi used a gene named Bmi1 to mark the presence of adult stem cells in the intestines of mice.
The geneticist duo was surprised to find the specific cells mostly in the upper third of the mouse intestine, as it hinted that at least one or two other types of adult stem cells must exist to maintain and repair the middle and lower thirds of the mouse's guts.
Capecchi pointed out that many scientists hope to transplant adult stem cells, which can become any type of cell in the organ in which they are found, to treat various diseases.
It is believed that the replacement of damaged insulin-producing cells in the pancreas, of cardiac muscle cells killed by heart attack, and of dopamine-producing cells damaged patients with Parkinson's disease may all be possible through adult stem cell transplants.
"(The new discovery) is important because people are talking about stem cell therapy; they want to stick in stem cells to treat disease," Nature Genetics quoted Capecchi as saying.
"People always thought about a uniform stem cell population in each organ, but now we are saying there are multiple stem cell populations in a given organ, so if you're going to do therapy, you have to recognize this complexity," added Capecchi, co-chair and distinguished professor of human genetics at the University of Utah and an investigator with the Howard Hughes Medical Institute.
Sangiorgi, a postdoctoral fellow in human genetics, said: "There are probably different stem cells in the small intestine doing different things."
Capecchi highlighted that if the regeneration of the intestinal lining required more than one kind of adult stem cell, "it wouldn't be surprising to see it is true for other organs as well."