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International Journal of Nephrology
Volume 2014, Article ID 512178, 10 pages
http://dx.doi.org/10.1155/2014/512178
Research Article

Classification of Five Uremic Solutes according to Their Effects on Renal Tubular Cells

Pharmaceutical Division, Kureha Corporation, 3-26-2 Hyakunin-cho, Shinjuku-ku, Tokyo 169-8503, Japan

Received 25 June 2014; Revised 19 September 2014; Accepted 6 October 2014; Published 9 November 2014

Academic Editor: Jochen Reiser

Copyright © 2014 Takeo Edamatsu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Background/Aims. Uremic solutes, which are known to be retained in patients with chronic kidney disease, are considered to have deleterious effects on disease progression. Among these uremic solutes, indoxyl sulfate (IS) has been extensively studied, while other solutes have been studied less to state. We conducted a comparative study to examine the similarities and differences between IS, p-cresyl sulfate (PCS), phenyl sulfate (PhS), hippuric acid (HA), and indoleacetic acid (IAA). Methods. We used LLC-PK1 cells to evaluate the effects of these solutes on viable cell number, cell cycle progression, and cell death. Results. All the solutes reduced viable cell number after 48-hour incubation. N-Acetyl-L-cysteine inhibited this effect induced by all solutes except HA. At the concentration that reduced the cell number to almost 50% of vehicle control, IAA induced apoptosis but not cell cycle delay, whereas other solutes induced delay in cell cycle progression with marginal impact on apoptosis. Phosphorylation of p53 and Chk1 and expression of ATF4 and CHOP genes were detected in IS-, PCS-, and PhS-treated cells, but not in IAA-treated cells. Conclusions. Taken together, the adverse effects of PCS and PhS on renal tubular cells are similar to those of IS, while those of HA and IAA differ.