[Versatility of adipose tissue as a source of stem cells]

The stem cells are promising for future cell-based therapy such as tissue engineering or regenerative medicine. Although Embryonic Stem Cells (ESCs) are theoretically highly beneficial, there are various limitations on their use posed by cell regulations and ethical considerations. Therefore, adult stem cells are considered to be highly available with neither ethical nor immunoreactive considerations as long as they are of autologous tissue origin. Much of work has focused on the Mesenchymal Stem Cells (MSCs) isolated from bone marrow stroma, which have been shown to possess adipogenic, osteogenic, chondrogenic, myogenic and neurogenic potential in vitro. However bone marrow procurement is severely painful for patients and the harvested cells yields low number. Our preliminary studies have identified a putative stem cell population isolated from human adipose tissue. This cell population, termed Processed Lipoaspirate Cells (PLA Cells), is found to differentiate into adipogenic, osteogenic, chondrogenic and myogenic lineage in vitro in lineage-specific culture media. In addition to these findings, our recent data shows that PLA cells can be induced to differentiate into neural precursors, which are of an ectodermal origin. Furthermore, PLA cells express multiple CD marker antigens similar to those observed on MSCs. Finally, some of PLA clonal cells have capabilities of differentiate into adipogenic, osteogenic and chondrogenic lineage. These findings suggest that human PLA have a mesodermal stem cell population. Since human adipose tissue is ubiquitous, easily obtainable in large quantity under local anesthesia with little patient discomfort, it may be an alternative stem cell source for mesenchymal tissue regeneration and engineering.