Philadelphia, Pa. Adult human stem cells taken from bone marrow have been induced to develop into a wide range of normal tissues, including bone, cartilage, fat, tendon and muscle, when transplanted into fetal sheep. The transplanted human cells have persisted in various sheep tissues for over one year without rejection by the sheeps immune system. The study offers promise that in the future these cells may be useful for tissue repair or regeneration and for treatment of degenerative diseases such as muscular dystrophy.

"Although a great deal of work remains to be done, these results suggest great potential for the use of these cells in repair of damaged or degenerating tissues, or for generation of new tissues, a process called tissue engineering," said Alan W. Flake, M.D., director of The Childrens Institute for Surgical Science at The Childrens Hospital of Philadelphia, who led the study reported in the November issue of Nature Medicine. "One possible future application might be the transplantation of normal stem cells into a fetus diagnosed with muscular dystrophy. "These cells could then act as a normal stem cell reservoir and replace the abnormal muscle with normal muscle as it degenerates over time."

Stem cells are immature cells that develop into specialized cells throughout the body, and those taken from embryos have the broadest potential for giving rise to all the bodys tissues. However, recent studies have shown that cells with broad stem cell potential can be found in various adult tissues as well, including the bone marrow and nervous system.

In the study at Childrens Hospital, researchers harvested mesenchymal stem cells (MSCs) from adult bone marrow. "The transplanted cells developed in a site-specific fashion," said Dr. Flake. "They migrated to different parts of the sheeps body and differentiated into types of tissue present at each site."

Because the transplanted cells carried human DNA, it was possible to identif
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Contact: Maria Stearns
stearnsm@email.chop.edu
215-590-4091
Children's Hospital of Philadelphia
30-Oct-2000