Response of renal tubular cells to differential types and doses of calcium oxalate crystals: Integrative proteome network analysis and functional investigations

We have previously identified changes in the cellular proteome of renal tubular cells induced by low-dose (100 μg/ml) and high-dose (1,000 μg/ml) calcium oxalate monohydrate (COM) and dihydrate (COD) crystals. However, the functional significance of such expression data remained unclear. In this study, we performed comparative analyses and functional investigations of four proteomic datasets to define potential mechanisms by which renal tubular cells responded to differential crystal types and doses. The data showed that high-dose induced greater changes than low-dose, whereas COM induced more changes than COD. Luciferin-luciferase ATP assay revealed increased intracellular ATP level by high-dose of both COM and COD. OxyBlot assay and Western blotting showed accumulated intracellular oxidized proteins but decreased ubiquitinated proteins by high-dose of both crystals. Flow cytometric analysis of cell death showed that high-dose of both crystals, particularly COM, significantly increased cell death. Also, crystal adhesion assay showed higher degree of cell-crystal adhesion in high-dose and COM when compared to low-dose and COD, respectively. Finally, pretreatment of epigallocatechin-3-gallate (EGCG) revealed a protective effect on COM/COD crystals-induced oxidative stress and cell-crystal adhesion. Collectively, these data may provide a better understanding of cellular responses of renal tubular cells to COM/COD crystals in kidney stone disease. This article is protected by copyright. All rights reserved.

Proteomics. 2017 Jun 19 [Epub ahead of print]

Arada Vinaiphat, Siripat Aluksanasuwan, Juthatip Manissorn, Suchitra Sutthimethakorn, Visith Thongboonkerd

Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital; and Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand.