Taxonomy of placenta cells

The placenta is considered one of the candidate cell sources in cellular therapeutics because of a large number of cells and heterogenous cell population with myogenic potentials. We first analyzed myogenic potential of cells obtained from six parts of the placenta, i.e., umbilical cord, amniotic epithelium, amniotic mesoderm, chorionic plate, villous chorion (chorion frondosum), , and decidua basalis. Implantation of placenta-derived cells into dystrophic muscles of immunodeficient mdx mice restored sarcolemmal expression of human dystrophin. Co-existence of human and murine nuclei in one myotube and presence of human dystrophin in murine myotube suggests that human dystrophin expression is due to cell fusion between host murine myocytes and implanted human cells. In vitro analysis revealed that cells derived from amniotic mesoderm, chorionic plate, ,and villous chorion efficiently transdifferentiate into myotubes. These cells fused to C2C12 murine myoblasts by in vitro co-culturing, and murine myoblasts start to express human dystrophin after fusion. These results demonstrate that placenta-derived cells, especially extraembryonic mesodermal cells, have a myogenic potential and regenerative capacity of skeletal muscle. Determination of cell specification with the gene chip analysis revealed that each placental cell has a distinct expression pattern.

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