U researchers might have found a solution in the struggle to find stem cells in adult organs.
Researcher Eugenio Sangiorgi and 2007 Nobel Prize winner Mario Capecchi found a way to use a relatively unknown gene in stem cell research to find adult stem cells in mice-an endeavor that began with a discussion four years ago and was published this week.
The two researchers have now found that the gene works, but in unexpected ways.
"We were expecting to use this gene to find adult stem cells throughout the small intestine, but we found that they are more highly concentrated in one part of the small intestine, and none in a different part," said Sangiorgi, a postdoctoral fellow in human genetics.
Religious communities and political organizations have criticized embryonic stem cell research because the cells derive from embryos fertilized from female eggs and male sperm in a specialized laboratory environment, which some consider a potential human life.
"Pro-life organizations feel (embryos) shouldn't be destroyed in the name of research," said Maxwell Mehlman, director of the Law-Medicine Center at Case Western Reserve University School of Medicine.
Adult stem cells have been considered an alternative for embryonic stem cells.
"(The new discovery) is important because people are talking about stem cell therapy," said Capecchi, a distinguished professor of human genetics, in a statement.
"They want to stick in stem cells to treat disease." Sangiorgi led the project to search for adult stem cells with a modified gene in mice, the study used a well-known technique using fluorescent painting to find the adult stem cells in the small intestine.
Researchers cannot differentiate between adult stem cells used for regenerative purposes and other cells in an organ.
Adult stem cells are rare in the human body, making them difficult to find, but they can be critical in fighting disease.
"It's like an army," Sangiorgi said. "A stem cell is like a general-you don't need very many because they can accomplish so much."
Sangiorgi and Capecchi modified the gene for this research by using the same knock-out technique for which Capecchi won the Nobel Prize for Medicine or Physiology. The mice were grown in the laboratory with an altered gene that allowed Sangiorgi to mark the cells that were activated by the gene.
The varied location of the adult intestinal stem cells is still a mystery.
"We don't know why there are different adult stem cells in different part of the small intestine," Sangiorgi said.
It took four years to complete the study, which included growing and observing the activated cells in the small intestine of the mice and publishing the research.
Sangiorgi said he is now studying the pancreas to see how well the modified gene works to locate adult stem cells in this organ.
It would be interesting to take the study further and find out why the adult stem cells are varied, Sangiorgi said.
"But at this time, we don't know how to study this or test the hypothesis," he said.
l.groves@chronicle.utah.edu
