Researchers Identify Stem Cell "Glue"

     Kansas City, Mo. - Researchers at the Stowers Institute for Medical Research are finding more clues that point to nurture as the winner in the "nature versus nurture" debate. Researchers have discovered that cell adhesion molecules in the fruit fly ovary act as a type of "cell glue" that attract stem cells to their specific microenvironment or stem cell " niche" and anchor them in place once there. This physical anchoring of the stem cell in its niche plays a vital role in maintaining the undifferentiated state and offers promise for the potential therapeutic use of stem cells to regenerate damaged tissue in humans.

     The findings are reported in the June 7 issue of Science.

     Stem cells have an infinite ability to reproduce, creating daughter cells that can then transform themselves into replacement cells based upon the instructions they receive. But in order to receive these instructions, the daughter cells must be in their niche. Research conducted in the laboratory of Ting Xie, Stowers Institute Assistant Scientist, shows that DE-cadherin-mediated cell adhesion, or "cell glue," helps stem cells find their niche, and then anchors them in place so that they can receive these vital instructions. Once the cell glue is lost, the stem cells are also lost and can no longer receive the instructions that control their actions.

     In conducting the research, the team found two proteins, DE-cadherin and b-catenin, that accumulate in high levels in the junctions between the fruit fly's germline stem cells and cap cells, one of the niche components. When these proteins were removed from germline stem cells, the stem cells disappeared.

     "Our research allows us to study the niche environment and the mechanism of communication between stem cells and their niches. As we learn more about how stem cells are first attracted to and then kept in their niche, we are better able to assess their structure, function and maintenance," Xie said. "This understanding is crucial in assessing the future use of stem cells in treating degenerative diseases such as Parkinson's, Alzheimer's and diabetes and in penetrating the mysteries of stem cell involvement in tumor formation and the aging process."

     Bill Neaves, Stowers Institute President & CEO said, "Dr. Xie's research demonstrates that the microenvironment is more important than the stem cell itself in determining its fate, information that lends hope to the thought that stem cells from any organ may be able to replace damaged cells in another organ if they find themselves in that organ's stem cell niche."

     This discovery builds upon previous research by Ting Xie and Allan Spradling at the Carnegie Institution of Washington, which demonstrated that stem cell function is regulated by environmental factors. The research was also supported by a grant from the National Institutes of Health.

     Situated on a 10-acre campus in the heart of Kansas City, Missouri, the Stowers Institute for Medical Research conducts research on the fundamental processes of cellular life. Through basic research of the highest quality, the Stowers Institute seeks insights that will lead to more effective ways of preventing and curing disease. The Institute was founded in 1994 by Jim and Virginia Stowers, two cancer survivors who have dedicated their fortune to supporting the basic research that will provide long-term solutions to gene-based diseases.