human iPSC-derived thyroid follicular cells maturation depends on time and duration of BMP-signaling

The goal of this experiment was to analyse transcriptomic changes of human iPSC-derived thyroid follicular cell progenitors and follicular cells in a time-dependend manner and understanding the impact of prolonged BMP-signaling on thyroid maturation. We compared human iPSC-derived thyrocyte progenitors at day 12 of differentiation with human iPSC-derived thycytes at day 29 of differentiation that were continiously cultured in presence of BMP4 or were cultured with BMP4 until day 14, followed by 15 days of culture with BMP4-withdrawal. Overall design: Transcriptomic profiling at single cell resolution of human iPSC-derived thyroid follicular cell progenitors at 12 days of differentiation, and thyroid follicular cells at 29 days of differentiation cultured in thyroid maturation medium containing or lacking BMP4. 1) d12 cells cultured in thyroid specification medium until day 12, 2) d29_BMP_sustained cells cultured in thyroid specification medium until day 14 and in thyroid maturation medium supplemented with BMP4 from day 15 to day 29, 3) d29_BMP_withdrawn cells cultured in thyroid specification medium until day 14 and in thyroid maturation medium not containing BMP4 from day 15 to day 29