Purpose of review: To review the potential of stem cells derived from amniotic fluid and applications in prenatal and postnatal therapy.
Recent findings: We have recently described that pluripotent stem cells can be isolated from amniotic fluid defined as amniotic fluid stem (AFS) cells by selection for expression of the membrane stem cell factor receptor c-Kit. AFS cells maintained for over 250 population doublings retained long telomeres and normal karyotype. Clonal human lines verified by retroviral marking were induced to differentiate into cell types representing each embryonic germ layer, including adipogenic, osteogenic, myogenic, endothelial, neuronal, and hepatic lineages. Rat AFS cells have been able to improve the repair of damaged smooth muscle in cryoinjury bladders. Furthermore, AFS cells could be differentiated toward cardiomyogenic lineages, when co-cultured with neonatal cardiomyocytes and have potential to generate hematopoietic lineages both in vitro and in vivo. These cells have been applied into fetal therapy, and widely used for tissue repair in animal models. Finally, we demonstrated a feasible way to do in-utero autologous AFS transplantation in sheep.
Summary: Stem cells derived from amniotic fluid are a relatively new source of cells that could have a therapeutic value in various diseases prenatally and/or postnatally.