Pluripotency of mesenchymal stem cells derived from adult marrow.

Yuehua Jiang et al., Pluripotency of Mesenchymal Stem Cells Derived from Adult Marrow, NATURE, JUNE 20, 2002, at .

Embryonic stem (ES) cells are pluripotent cells derived from the inner cell mass of the blastocyst that can be propagated indefinitely in an undifferentiated state. ES cells differentiate to all cell lineages in vitro and differentiate into many cell types in vitro. Although ES cells have been isolated from humans, their use in research as well as therapeutics is encumbered by ethical considerations. Stem cells also exist for most tissues, including hematopoietic, neural, gastrointestinal, epidermal, hepatic and mesenchymal stem cells. Compared with ES cells, tissue-specific stem cells have less self-renewal ability and, although they differentiate into multiple lineages, they are not pluripotent.

Until recently, it was thought that tissue-specific stem cells could only differentiate into cells of the tissue of origin; however, recent studies suggest that tissue-specific stem cells can differentiate into lineages other than the tissue of origin. After transplantation of bone marrow or enriched hematopoietic stem cells (HSC), skeletal myoblasts, cardiac myoblasts, endothelium, hepatic and biliary duct epithelium, lung, gut and skin epithelia, and neuroectodermal cells of donor origin have been detected. Some studies demonstrated that neural stem cells as well as muscle cells may differentiate into...