Chapter 12 - Stem Cells from Amniotic Fluid

Abstract

This chapter provides an overview of the potential advantages and disadvantages of different stem and progenitor cell populations identified to date in amniotic fluid, along with their properties and potential clinical applications. Two stem cell populations are isolated from the AF that include amniotic fluid mesenchymal stem cells (AFMSCs) and amniotic fluid stem (AFS) cells and both can be used as primary (not transformed or immortalized) cells without further technical manipulations. AFMSCs exhibit typical mesenchymal stromal cell (MSC) characteristics such as fibroblastic-like morphology, clonogenic capacity, multilineage differentiation potential, immunosuppressive properties, and expression of a mesenchymal gene expression profile and of a mesenchymal set of surface antigens. AFMSCs are easier to isolate and show better proliferation capacities. The harvest of bone marrow remains, in fact, a highly invasive and painful procedure, and the number, the proliferation, and the differentiation potential of these cells decline with increasing age. Similarly, UCB-derived MSCs exist at a low percentage and expand slowly in culture. AFS cells represent a novel class of pluripotent stem cells with intermediate characteristics between ES cells and AS cells. They express both embryonic and mesenchymal stem cell markers, are able to differentiate into lineages representative of all embryonic germ layers, and do not form tumors after implantation in vivo. AFS cells may not differentiate as promptly as ES cells and their lack of tumorigenesis can be argued against their pluripotency.