Usefulness of kidney slices for functional analysis of apical reabsorptive transporters

Abstract

Kidney plays a key role in the elimination and reabsorption of drugs and nutrients, however in vitro methods to evaluate renal disposition are limited. In the present study, we investigated usefulness of isolated kidney slice, which had been used for transport only at basolateral membrane of tubular epithelial cells, for evaluation of apical membrane transporters. As transporters that are easy to discriminate between apical and basolateral transports, apical membrane specific and sodium-dependent transporters (SGLTs and OCTNs) and pH-dependent transporters (PEPTs) are selected. Uptake of ergothioneine, carnitine and methyl-α-D-glucopyranoside, which are substrates of apical Octn1, Octn2, and Sglt1/2, respectively, by mice kidney slices showed clear Na+ dependence and reduction by selective inhibitors. In addition, sodium dependence of ergothioneine uptake was negligible in the kidney slice from Octn1-gene deficient mice. Moreover, uptake of PepT1/2 substrate glycyl-sarcosine, was higher than that in the presence of glycyl-leucine, a non-specific Pept inhibitor. The K m and IC 50 values for substrates and inhibitors of each transporter were mostly comparable to those obtained in transporter-transfected cells. In conclusion, it was demonstrated that kidney slices are promising tool to study transporters expressed at the apical membranes as well as basolateral membranes of kidney tubular epithelial cells.

Effect of tyrosine kinase inhibitors on renal handling of creatinine by MATE1

“…Uptake study by rat kidney slices was carried out as described previously, with slight modifications 31 . Whole kidneys of male rats were sliced (0.3 mm thick) with a microslicer (Zero 1; Dosaka EM, Kyoto, Japan).…”

Improvement of Protein Expression Profile in Three-Dimensional Renal Proximal Tubular Epithelial Cell Spheroids Selected Based on OAT1 Gene Expression: A Potential In Vitro Tool for Evaluating Human Renal Proximal Tubular Toxicity and Drug Disposition

“…8). The following two possibilities were considered as reasons why basolateral OAT1 activity was not detected in 3D RPTEC spheroids: 1) apical and basal transporter activities cannot be evaluated separately because both apical transporters are exposed to the buffer as well as in vitro kidney slice systems (Arakawa et al, 2017(Arakawa et al, , 2019,…”

Delivery and Transcriptome Assessment of an In Vitro Three-Dimensional Proximal Tubule Model Established by Human Kidney 2 Cells in Clinical Gelatin Sponges

“…Renal proximal tubular cells (PTCs) exhibit high metabolic activity and contain a variety of carriers and transporters differentially localized on the apical or basolateral membranes [3]. Through the complex work of drug transporters, the PTCs are a major route to excrete drugs and xenobiotics [4,5].…”