Figure 4.

Reproducibility and maturity of kidney spheroids. (a) FACS analysis of tubule segment markers in mouse kidney spheroid generated by immortalized cells at the 4^th and 20^th passages. As a positive control, dissociated mouse whole kidney (at 6 weeks of age) was used. Mouse kidney spheroid at the 4^th and 20^th passages and dissociated whole mouse kidney were stained with anti-AQP1, PNA, nephrin, or AQP2 (open histograms), or isotype control mAb (grey histograms). (b) Quantitative RT-PCR analysis of kidney-specific segment markers in mKidS generated by cells at the 4^th and 20^th passages compared with 2D controls (2D CTL). n = 8 for 2D CTL and n = 6 for mKidS at the 4^th and 20^th passages. (c,d) Relative mRNA expression of apical (c) and basolateral (d) transporters in mKidS at the 4^th and 20^th passages compared with 2D cultured cells. n = 8 for 2D CTL and n = 6 for mKidS at the 4^th and 20^th passages. (e) Responses to parathyroid hormone (PTH) of mKidS at the 4^th and 20^th passages compared to 3D CTL. (f) GGT activity in mKidS at the 4^th and 20^th passages compared to 3D CTL. (g) Alexa Fluor 488-conjugated dextran uptake of mKidS at the 4^th and 20^th passages compared with 3D CTL. n = 6 for 3D CTL and mKidS at the 4^th and 20^th passages for E-G. All data are shown as the means ± s.e.m. *p < 0.05 compared with 2D or 3D control by unpaired Student’s t-test.