Enrichment in c-Kit improved differentiation potential of amniotic membrane progenitor/stem cells

Abstract

Introduction: Human term placenta has attracted increasing attention as an alternative source of stem cells for regenerative medicine since it is accessible without ethical objections. The amniotic membrane (AM) contains at least two stem cell types from different embryological origins: ectodermal amniotic epithelial stem cells, and mesodermal mesenchymal stromal cells. Among the second group we studied the characteristics of amniotic mesenchymal cells (AMC) versus the ones enriched for the commonly used surface marker c-Kit (amniotic progenitor/stem cells-ASC), a stem cell factor receptor with crucial functions in a variety of biological systems and presents in early progenitors of different origin, as been already demonstrated in the enriched chorionic stem cells.

Methods: After isolation, cells from the amniotic membranes (amniotic cells-AC) were selected for c-Kit (ASC) and compared these cells with c-Kit unselected (AMC), evaluating the expression of other stem cell markers (Oct-4, Tra-1-81, SSEA-4), CD271 and Slug.

Results: Immunofluorescence analysis showed that ASC cells exhibited greater stem cell marker expression and included more CD271 and Slug positive cells. This was consistent with the interpretation that c-Kit enriched AC show greater stemness capacity compared to c-Kit unselected AMC.

Discussion: AMC and ASC can both differentiate into various cell types including adipogenic, osteogenic, chondrogenic, neurogenic and hepatic lineages, but the enrichment in c-Kit improved stemness and differentiation potential of ASC.

Keywords: Amniotic membrane; Human amniotic stem cells; Oct-4; Placenta; Pluripotency markers; c-Kit.