Fig. 2: hiPSC-derived salivary gland organoids are structurally and functionally similar to salivary gland tissues.

a, Phase-contrast image of an aggregate on day 60 before isolation. The image is representative of 18 independent experiments. Scale bar, 200 μm. b, Left, representative phase-contrast image of an isolated hiSG on day 80. Middle and right, representative stereomicroscopic images of an hiSG on day 80. The images are representative of 18 independent experiments. Scale bars, 200 μm. c, Immunofluorescence images of hiSGs on day 80. The images are representative of four independent experiments showing similar results. Scale bars, 200 μm (top left) and 50 μm. d, Heatmap of the gene sets of adult salivary glands (SOX9, FOXC1, SOX10, AQP5, ACTA2 and CHRM3), embryonic salivary glands (ETV5, SPRY1 and SPRY2), pluripotent stem cells (SOX2 and NANOG) and other branching organs (PDX1 and NKX2.1). Data are shown for hiSGs on day 80 (n = 3 biological replicates), human embryonic SMGs, adult SMGs, adult parotid glands (PARs) and adult sublingual glands (SLGs). e, Representative data from hiSG calcium release analysis. Fluo-4 was used to measure the calcium concentrations inside cells. hiSGs were stimulated with two concentrations of carbachol (CCh) (100 μM or 10 μM) or pretreated with atropine (ATR), followed by 100 μM CCh. Changes in the Fluo-4 fluorescence intensity were recorded. This experiment was replicated three times with similar results. a.u., arbitrary unit.