SATB homeobox 1 regulated genes in the mouse ectoplacental cone are important for placental development

SATB homeobox 1 (SATB1) is abundantly expressed in the stem-state of trophoblast cells but downregulated during trophoblast differentiation. It is also expressed in high levels in the mouse ectoplacental cones (EPCs). We detected that SATB1 is involved in maintaining the self-renewal of trophoblast stem cells and inhibiting trophoblast differentiation. In this study, we have identified SATB1-regulated genes in the mouse EPC and analyzed their potential functions. A total of 1618 differentially expressed genes were identified in Satb1null EPCs by mRNA sequencing. Remarkably 90% of the differentially expressed genes were found to be upregulated in Satb1null EPCs suggesting a transcriptional repressor role of SATB1 in mouse trophoblast cells. Ingenuity Pathway Analyses demonstrated that the differentially expressed genes in Satb1null EPCs are particularly linked to WNT and TGF{beta} signaling pathways, which regulate self-renewal of stem cells and cell differentiation. Moreover, twenty-six of the EPC genes that are known to be involved in placental development including Eomes, Epas1, Fgfr2, Cdkn1c, and Plac9 were found dysregulated in Satb1null EPCs due to the loss of SATB1 expression. These genes are particularly involved in the formation of labyrinthine zone. Our results emphasize that SATB1-regulated genes in the mouse EPC contribute to key roles in the regulation of trophoblast differentiation and placental development.