The IL-33/ST2L/sST2 axis in decidualizing HESCs.

<p>(<i>A</i>) Total ST2 transcript levels were measured in primary HESC cultures treated with 8-bromo-cAMP (cAMP) and MPA for the indicated time-points. (<i>B</i>) ST2L mRNA levels, expressed in arbitrary units (A.U.), were determined in primary cultures decidualized for 2–8 days (upper panel). Total cell lysates from parallel cultures were probed for ST2L expression (lower panel). β-actin served as a loading control. (<i>C</i>) The culture supernatant was harvested every 48 h and the levels of accumulated sST2 determined by ELISA. (<i>D</i>) Induction and release of IL-33 in decidualizing cells. Il-33 mRNA and protein was readily detectable in undifferentiated HESCs. IL-33 mRNA levels increased rapidly in response to cAMP and MPA (upper panel) but total cellular protein levels gradually declined upon decidualization (lower panel). (<i>E</i>) Il-33 rapidly accumulated in culture supernatant in response to cAMP and MPA signalling (<i>F</i>) HESCs cultured on chamber slides were decidualized for 12 h and stained for IL-33 expression (green). The nuclei were visualized with DAPI (not shown). The overlayed images were captured by confocal microscopy. Scale bar: 25 µm. Quantitative data represent the mean (± SD) of biologically triplicate experiments.