PROP1 triggers epithelial-mesenchymal transition-like process in pituitary stem cells [RNA-Seq]

Mutations in PROP1 are the most common cause of hypopituitarism in humans; therefore, unraveling its mechanism of action is highly relevant from a therapeutic perspective. Our current understanding of the role of PROP1 in the pituitary gland is limited to the regulation of pituitary transcription factors Hesx1 and Pit1. To elucidate the comprehensive PROP1-dependent gene regulatory network, we conducted genome wide analysis of PROP1 DNA binding and effects on gene expression in mutant tissues, isolated stem cells and engineered cell lines. We determined that PROP1 is essential for maintaining proliferation of stem cells and stimulating them to undergo an epithelial to mesenchymal transition-like process necessary for cell migration and differentiation. Genomic profiling reveals that PROP1 binds to and represses claudin 23, characteristic of epithelial cells, and it activates EMT inducer genes: Zeb2, Notch2 and Gli2. Our findings identify PROP1 as a central transcriptional component of pituitary stem cell differentiation. Overall design: Pituitary Colony forming cells mRNA of 13-day old wild type (Prop1 +/+), Prop1 mutants (Prop1df/df), wild type (Pit1+/+) and Pit1 mutants (Pit1 dw/dw) mice were generated by deep sequencing, in triplicates.

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Pérez Millán MI, Brinkmeier ML, Mortensen AH, Camper SA