Side population cells in the human decidua of early pregnancy exhibit stem/progenitor cell-like characteristics

Abstract

It is proposed that human decidua contains a population of stem cells that are responsible for the proliferation ability during the process of embryo implantation and placenta formation and that factors in the crosstalk between the decidua and chorion may mediate decidual stem cell differentiation. This study analysed the phenotype of side population (SP) cells and investigated the clonogenicity and differentiation ability of SP cells in human decidua of early pregnancy. Serum-free culture-conditioned media of human decidua and chorion were obtained from decidua and chorion explant culture. Decidual SP cells were isolated by fluorescence-activated cell sorting. Different inducing media were added and the functional differentiation of decidual SP cells was examined. Decidual SP cells were negative for the mature decidual cell marker CD13 and prolactin and negative for CD34 and CD45 expression. Decidual SP cells formed clones after culture in colony-forming medium and they could form clones again. Differentiated cells expressing CD13 and prolactin were observed and stroma-like structures expressing CD13 were obtained. These results indicate that decidual SP cells are enriched for stem cell activity. Oestradiol, progesterone and factors in culture-conditioned media of human decidua and chorion induced their proliferation and differentiation.