摘要

Mouse trophoblast stem (TS) cells represent a unique in vitro system that provides an unlimited supply of TS cells for the study of trophoblast differentiation and TS cell self-renewal. Although the mouse transcription factor Ets2 is required for IS cell self-renewal, its role in this and in IS cell differentiation has not been explored fully, partly due to the early lethality of Ets2 null mice. To address this, we developed a novel lentivirus-based system that resulted in efficient Ets2 knockdown in the overwhelming majority of IS cells; This system enables functional studies in TS cells, especially for genes required for TS cell self-renewal because IS cell derivation using gene-knockout embryos for such genes depends on TS cell self-renewal. Using morphological/morphometric criteria and gene expression analysis, we show that the requirement for Ets2 in self-renewal of TS cells cultured in 'stem cell medium' (SCM) involves maintenance of the expression of genes that inhibit IS cell differentiation in SCM, such as Cdx2 and Esrrb, and preservation of the undifferentiated TS cell morphology. During IS cell differentiation caused by Cdx2/Esrrb downregulation, due to either Ets2 knockdown in SCM or culture in differentiation medium (DM), Ets2 is also required for the promotion of trophoblast giant cell (TGC) and junctional zone trophoblast (JZT) differentiation. This TGC differentiation involves Ets2-dependent expression of Hand1, a gene required for the differentiation of all TGC types. This study uncovers new roles for Ets2 in IS cell sel-frenewal and differentiation and demonstrates the usefulness of this lentivirus system for gene function studies in TS cells.

  • 出版日期2010-7