Distribution of soluble uranium in the nuclear cell compartment at subtoxic concentrations.
Uranium is naturally found in the environment, and its extensive use results in an increased risk of human exposure. Kidney cells have mainly been used as in vitro models to study effects of uranium exposure, and very little about the effects on other cell types is known. The aim of this study was to assess the impact of depleted uranium exposure at the cellular level in human kidney (HEK-293), liver (HepG2), and neuronal (IMR-32) cell lines. Cytotoxicity studies showed that these cell lines reacted in a roughly similar manner to depleted uranium exposure, responding at a cytotoxicity threshold of 300-500 μM. Uranium was localized in cells with secondary ion mass spectrometry technology. Results showed that uranium precipitates at subtoxic concentrations (>100 μM). With this approach, we were able for the first time to observe the soluble form of uranium in the cell at low concentrations (10-100 μM). Moreover, this technique allows us to localize it mainly in the nucleus. These innovative results raise the question of how uranium penetrates into cells and open new perspectives for studying the mechanisms of uranium chemical toxicity.
Institut de RadioProtection et de Sureté Nucléaire, Direction de la Radioprotection de l’Homme, Service de Radiobiologie et d’Epidémiologie, Laboratoire de Radiotoxicologie Expérimentale, BP17, F-92262 Fontenay-aux-Roses, France.
Caroline
C
Rouas
Helene
H
Bensoussan
David
D
Suhard
Christine
C
Tessier
Line
L
Grandcolas
François
F
Rebiere
Isabelle
I
Dublineau
Mohammed
M
Taouis
Marc
M
Pallardy
Philippe
P
Lestaevel
Yann
Y
Gueguen
D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004785:Environmental Pollutants / Q000032:analysis / Q000633:toxicity*; D006801:Humans; D018629:Spectrometry, Mass, Secondary Ion; D014501:Uranium / Q000032:analysis / Q000633:toxicity*
D004785:Environmental Pollutants; D014501:Uranium