Time course of organoid growth and gene expression in WT and TBX19K146R/K146R organoids
A, Culture protocol and schematic to generate pituitary organoids in three-dimensional (3D) culture from hiPSC. Organoids were collected at days (d) 0, 6, 18, 27, 48, 75, and 105 during differentiation to analyze.
B, Bright-field microscopy views of WT organoid examples at different time points throughout differentiation. Scale bars are indicated in each image.
C-G, Relative quantification (RQ) mRNA expression analysis for key markers of pituitary organoids during differentiation: WT (in black line) and TBX19K146R/K146R organoids (in green line). Data show means ± standard error of the mean (SEM); n=1 on day (d)0, n=3 samples per group (8 organoids per sample) at the time points d6 and d18, n=4-8 organoids per group at each subsequent time point (d27, d48, d75 and d105). Mann-Whitney t-test (unpaired, two-tailed, nonparametric). p < 0.05 (*), p< 0.01 (**).
C, Relative quantification expression of HESX1, one of the earliest pituitary placode markers. The expression of HESX1 was not significantly different in TBX19K146R/K146R organoids vs. WT.
D, Relative quantification expression of PITX1, an anterior pituitary progenitor marker in the ectodermal primordium. PITX1 was significantly downregulated in TBX19K146R/K146R organoids by d48 (** p= 0.0022) and d75 (* p= 0.0159).
E, Relative quantification expression of LHX3, a pituitary progenitor transcription factor. LHX3 was significantly lower in TBX19K146R/K146R organoids as compared to WT on d27 (** p= 0.004), d48 (** p= 0.0022) and d75 (** p=0.0079).
F, Relative quantification expression of TBX19, a corticotroph lineage marker. There was no significant difference in TBX19 expression between the two groups (p= 0.195, d75).
G, Relative quantification expression of POMC, a differentiated corticotroph marker. POMC was significantly downregulated in TBX19K146R/K146R organoids by d48 (* p= 0.026) and thereafter (* p= 0.0159 on d75; * p= 0.0317 on d105).