Figure 2
From: Bioengineered kidney tubules efficiently excrete uremic toxins
Handling of indoxyl sulfate and kynurenic acid by OAT1, BCRP and MRP4 in flat monolayers.
In matured ciPTEC-OAT1, a concentration-dependent uptake of (a) IS and (b) KA (white) was shown using LC-MS/MS analysis of the uremic toxins. In the presence of probenecid (P, grey), the uptake of both toxins was attenuated. Moreover, the IS uptake was inhibited in the presence of KA (100 μM; black) and vice versa. The role of BCRP and MRP4 in the efflux of IS and KA was shown using an MTT assay. The experiment was performed in the absence (•) or presence (◦) of efflux pump inhibitors (KO143 (10 μM) and MK571 (5 μM)). Nonlinear regression analysis was performed using Graphpad Prism 5.02. Data are shown as mean ± S.E.M. of three independent experiments performed in triplicate. *p < 0.05, ***p < 0.001 using one-way ANOVA analysis followed by Dunnett’s multiple comparison test.
