Effects of various man-made mineral fibers on cell apoptosis and viability.
Evaluating the pathogenic potentials of man-made mineral fibers (MMMF) is an important task performed by the European Community. Noting that it has been proposed that the use of laboratory animals for scientific tests should be reduced or phased out, macrophages then become the cells of choice for conducting in vitro studies. We have evaluated the in vitro toxicity of six commercial stonewool fibers (A, B1, B2, C, D, and E) on U-937 cells. The physical interaction between U-937 cells and MMMF was observed using scanning electron microscopy, and the cytotoxicity was evaluated by studying cell viability using MTT assay and cell apoptosis with an ELISA detection kit. Scanning electron microscopy (SEM) analysis has shown that long fibers can be covered by several macrophages, and that a small fiber can be completely engulfed by one cell. With 50 microg/mL of MMMF, a decrease in cell viability appeared after seven days of incubation, whereas 200 microg/mL induced loss of viability and apoptosis after one day. Fiber D, comprising a high proportion of fibers >20 microm in length and a high concentration of MgO, induced the highest loss in viability and the highest rate of apoptosis compared to the other five fibers. Whether this toxic effect is related to either the physical characteristics of the fibers (such as length), or to the high concentration of magnesium is still to be determined. Because the results can be rapidly obtained, the proposed model is suitable for studying the toxicities of mineral components, even if the tested concentrations are far from the ones reached in the lung.
Dika Nguea
Hermine
H
Laboratoire de Bactériologie-Virologie, Faculté de Médecine de Nancy, Unité Mixte de Recherche CNRS-UHP, 7565, BP 184, 54505 Vandoeuvre-lès-Nancy, France. hermine.dika-nguea@saint-gobain.com
Rihn
Bertrand
B
Mahon
Delphine
D
Bernard
Jean-Luc
JL
De Reydellet
Aymon
A
Le Faou
Alain
A
D017209:Apoptosis / Q000187:drug effects*; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007202:Indicators and Reagents; D008264:Macrophages / Q000187:drug effects / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D019016:Mineral Fibers / Q000032:analysis / Q000633:toxicity*; D009000:Monocytes / Q000187:drug effects / Q000648:ultrastructure; D009707:Nucleosomes / Q000187:drug effects / Q000648:ultrastructure; D013778:Tetrazolium Salts; D013844:Thiazoles; D020298:U937 Cells
D007202:Indicators and Reagents; D019016:Mineral Fibers; D009707:Nucleosomes; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue