Toxicity assays in nanodrops combining bioassay and morphometric endpoints.
BACKGROUND
Improved chemical hazard management such as REACH policy objective as well as drug ADMETOX prediction, while limiting the extent of animal testing, requires the development of increasingly high throughput as well as highly pertinent in vitro toxicity assays.


METHODS
This report describes a new in vitro method for toxicity testing, combining cell-based assays in nanodrop Cell-on-Chip format with the use of a genetically engineered stress sensitive hepatic cell line. We tested the behavior of a stress inducible fluorescent HepG2 model in which Heat Shock Protein promoters controlled Enhanced-Green Fluorescent Protein expression upon exposure to Cadmium Chloride (CdCl2), Sodium Arsenate (NaAsO2) and Paraquat. In agreement with previous studies based on a micro-well format, we could observe a chemical-specific response, identified through differences in dynamics and amplitude. We especially determined IC50 values for CdCl2 and NaAsO2, in agreement with published data. Individual cell identification via image-based screening allowed us to perform multiparametric analyses.


CONCLUSIONS
Using pre/sub lethal cell stress instead of cell mortality, we highlighted the high significance and the superior sensitivity of both stress promoter activation reporting and cell morphology parameters in measuring the cell response to a toxicant. These results demonstrate the first generation of high-throughput and high-content assays, capable of assessing chemical hazards in vitro within the REACH policy framework.
Lemaire
Frédéric
F
Commissariat à l'Energie Atomique, DSV, Cellular Responses and Dynamics Department, Laboratoire Biopuces, Commissariat à l'Energie Atomique Centre de Grenoble, Grenoble, France.
Mandon
Céline A
CA
Reboud
Julien
J
Papine
Alexandre
A
Angulo
Jesus
J
Pointu
Hervé
H
Diaz-Latoud
Chantal
C
Lajaunie
Christian
C
Chatelain
François
F
Arrigo
André-Patrick
AP
Schaack
Béatrice
B
D000818:Animals; D001149:Arsenates / Q000494:pharmacology; D001681:Biological Assay / Q000295:instrumentation / Q000379:methods*; D019256:Cadmium Chloride / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000494:pharmacology / Q000633:toxicity; D005786:Gene Expression Regulation; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000235:genetics; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006540:Herbicides / Q000494:pharmacology; D057166:High-Throughput Screening Assays / Q000295:instrumentation / Q000379:methods; D006801:Humans; D046228:Microarray Analysis / Q000295:instrumentation / Q000379:methods; D049329:Nanostructures; D010269:Paraquat / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D018675:Toxicity Tests / Q000295:instrumentation / Q000379:methods*
D001149:Arsenates; D004785:Environmental Pollutants; D006360:Heat-Shock Proteins; D006540:Herbicides; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C009277:sodium arsenate; D019256:Cadmium Chloride; D010269:Paraquat