Research initiated by Johns Hopkins has found that a mouse bone marrow stem cell is capable of developing into the specialized cells lining intestines, lung and skin. This study provides some of the first clear evidence that a transplanted bone marrow stem cell can not only reconstitute bone marrow but also may play a role in healing these other tissues and organs as well. The findings are reported in the May 4 issue of Cell.
"This study suggests that an infusion of stem cells after toxic cancer treatments may be able to repair damaged tissue throughout the body and serve as treatments for a variety of diseases characterized by tissue and organ damage, such as diabetes and cystic fibrosis," says Saul Sharkis, professor of oncology at the Johns Hopkins Oncology Center and director of the study.
Bone marrow stem cells differentiate and develop into all other blood and marrow cells. The new findings suggest that they also differentiate into other cells in the lining, or epithelium, of various tissues. "It is possible that stem cells are 'summoned' to sites of injury by factors secreted by the damaged organ," Sharkis says.
Sharkis studied five mice transplanted with a single purified mouse bone marrow stem cell. The mice were first treated with high doses of radiation, which destroyed the bone marrow and the lining of tissues and organs such as the intestine and lung. The stem cell, from a male mouse, was tagged with a fluorescent dye, allowing investigators to track and recover the cells made by the single transplanted cell after transplantation into female mice. In the five mice, researchers discovered descendants of the stem cell had not only become blood and marrow cells but also cells in the lining of the lung, intestinal tract and skin.
Though these early findings cannot yet be translated to patient treatment, Sharkis says, they are bringing researchers one step closer to understanding the therapeutic potential of bone marrow stem cells. Further studies on the mechanism of how the stem cells migrate and differentiate are under way.
Co-participants in this research were Diane Krause and Octavian Henegariu of Yale University School of Medicine; Neil Theise, Sonya Hwang and Rebekah Gardner of New York University Medical School; and Michael Collector and Sara Neutzel of Johns Hopkins.
The research was funded by the National Institutes of Health, the American Liver Foundation, Mary Lea Johnson Richards Research Institute and the Robert Kriefer Memorial Fund.