Fig. 3: Effect of MSL-7 on the clearance of endogenous hIAPP oligomer in human β-cells differentiated from hiPSCs.

a Expression of insulin and nuclear translocation of TFEB (left) or TFE3 (right) in human β-cells differentiated from human induced pluripotent stem cells (hiPSCs). Inset images were magnified to show cyan nuclei due to colocalization of TFEB with nuclear DAPI or yellow cytoplasm due to colocalization of TFEB with insulin⁺ cytoplasm. b Islet-like clusters differentiated from hiPSCs were treated with MSL-7 in the presence or absence of 3-MA for 16 h. After double immunofluorescence using A11 and anti-insulin antibodies as the primary antibodies, confocal microscopy was conducted and the number of A11⁺ puncta in insulin-producing β-cells was counted (F = 357.2, df treatment = 3, df residual = 76) (lower). Representative pictures are presented (upper). Inset images were magnified. c After treatment of islet-like clusters differentiated from hiPSCs cells with MSL-7 in the presence or absence of 3-MA for 16 h, combined TUNEL staining and insulin immunofluorescence were conducted, and the percentage of TUNEL⁺ apoptotic cells among insulin-producing β-cells was counted (F = 150.3, df treatment = 3, df residual = 76) (lower). Representative pictures are presented (upper). Inset images were magnified to show cyan nuclei due to colocalization of TUNEL staining with nuclear DAPI. All data in this figure are the means ± SEM from more than 3 independent experiments. (n = 20 islet-like clusters in a, b, c) (scale bar, 50 μm for a and 100 μm for b, c) ***P < 0.001 by one-way ANOVA with Tukey’s test.