Fig. 1

The epithelial barrier integrity, polarity, and PT cell proliferation deteriorate upon acute hypoxic tubular injury. (A) The barrier integrity assay revealed increased permeability for the 3D-Hypoxia group against both 20 kDa- and 155 kDa-Dextran. (n = 28) (B) Permeabilization indexes revealed increased permeability for the 3D-Hypoxia group against 3D-Normoxia for both 20 kDa- and 155 kDa-Dextran. (n = 28) (C) ZO-1 (Alexa Fluor 594) and acetylated α-tubulin (FITC) immunolabelling showed structurally intact and polarized PT epithelial cells in 2D- and 3D-Normoxia groups compared to the loss of polarity in 2D- and 3D-Hypoxia groups. (n = 36) (D) The CTFI detected a decrease in ZO-1 immunolabelling compared to 3D-Normoxia in 48 h compared to 0–24 h. (n = 36) (E) Calculated CTFI revealed a decline in acetylated α-tubulin immunolabelling in 3D-Hypoxia in 48 h. (F) The CTFI detected an increase in acetylated α-tubulin immunolabelling in 3D-Normoxia compared to the 2D-Normoxia, indicating amplification of polarization with fluid flow. (n = 18) (G) The CTFI of ZO-1 was similar in 2D and 3D setups in normoxia. (n = 18) (H) WST-1 assay detected a decrease in proliferation rate of PT cells in 2D-Hypoxia compared to 2D-Normoxia in both 24 and 48 h. The proliferation rate of 2D-Hypoxia was similar to 3D-Normoxia in 24 h and was decreased at 48 h. (n = 56) Data in scattered dot plots (B), (D-E) and (G-H) are mean ± SD. Data in scattered dot plot (F) are median ± interquartile range. (*) denotes (p < 0.05) comparing the groups in the indicated time point