Effect of Ba(II), Eu(III), and U(VI) on rat NRK-52E and human HEK-293 kidney cells in vitro

authored by

Christian Senwitz, Daniel Butscher, Linus Holtmann, Manja Vogel, Robin Steudtner, Björn Drobot, Thorsten Stumpf, Astrid Barkleit, Anne Heller

Abstract

Heavy metals pose a potential health risk to humans when they enter the organism. Renal excretion is one of the elimination pathways and, therefore, investigations with kidney cells are of particular interest. In the present study, the effects of Ba(II), Eu(III), and U(VI) on rat and human renal cells were investigated in vitro. A combination of microscopic, biochemical, analytical, and spectroscopic methods was used to assess cell viability, cell death mechanisms, and intracellular metal uptake of exposed cells as well as metal speciation in cell culture medium and inside cells. For Eu(III) and U(VI), cytotoxicity and intracellular uptake are positively correlated and depend on concentration and exposure time. An enhanced apoptosis occurs upon Eu(III) exposure whereas U(VI) exposure leads to enhanced apoptosis and (secondary) necrosis. In contrast to that, Ba(II) exhibits no cytotoxic effect at all and its intracellular uptake is time-independently very low. In general, both cell lines give similar results with rat cells being more sensitive than human cells. The dominant binding motifs of Eu(III) in cell culture medium as well as cell suspensions are (organo-) phosphate groups. Additionally, a protein complex is formed in medium at low Eu(III) concentration. In contrast, U(VI) forms a carbonate complex in cell culture medium as well as each one phosphate and carbonate complex in cell suspensions. Using chemical microscopy, Eu(III) was localized in granular, vesicular compartments near the nucleus and the intracellular Eu(III) species equals the one in cell suspensions. Overall, this study contributes to a better understanding of the interactions of Ba(II), Eu(III), and U(VI) on a cellular and molecular level. Since Ba(II) and Eu(III) serve as inactive analogs of the radioactive Ra(II) and Am(III)/Cm(III), the results of this study are also of importance for the health risk assessment of these radionuclides.

Organisation(s)

Centre for Radiation Protection and Radioecology

External Organisation(s)

Technische Universität Dresden
VKTA – Strahlenschutz, Analytik & Entsorgung Rossendorf e.V (VKTA)
Helmholtz-Zentrum Dresden-Rossendorf (HZDR)

Type

Article

Journal

Science of the Total Environment

Volume

923

No. of pages

20

ISSN

0048-9697

Publication date

01.05.2024

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Environmental Engineering, Environmental Chemistry, Waste Management and Disposal, Pollution

Sustainable Development Goals

SDG 3 - Good Health and Well-being

Electronic version(s)

https://doi.org/10.1016/j.scitotenv.2024.171374 (Access: Open)