TY - JOUR
T1 - Toxicity, recovery, and resilience in a 3D dopaminergic neuronal in vitro model exposed to rotenone
AU - Harris, Georgina
AU - Eschment, Melanie
AU - Orozco, Sebastian Perez
AU - McCaffery, J. Michael
AU - Maclennan, Richard
AU - Severin, Daniel
AU - Leist, Marcel
AU - Kleensang, Andre
AU - Pamies, David
AU - Maertens, Alexandra
AU - Hogberg, Helena T.
AU - Freeman, Dana
AU - Kirkwood, Alfredo
AU - Hartung, Thomas
AU - Smirnova, Lena
N1 - Funding Information:
Acknowledgements We would like to acknowledge the International Foundation for Ethical Research Graduate Fellowship Funding provided to Georgina Harris, and help from Erin Pryce from the Integrated Imaging Core Facility at Johns Hopkins University. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 681002.
Publisher Copyright:
© 2018, The Author(s).
PY - 2018/8/1
Y1 - 2018/8/1
N2 - To date, most in vitro toxicity testing has focused on acute effects of compounds at high concentrations. This testing strategy does not reflect real-life exposures, which might contribute to long-term disease outcome. We used a 3D-human dopaminergic in vitro LUHMES cell line model to determine whether effects of short-term rotenone exposure (100 nM, 24 h) are permanent or reversible. A decrease in complex I activity, ATP, mitochondrial diameter, and neurite outgrowth were observed acutely. After compound removal, complex I activity was still inhibited; however, ATP levels were increased, cells were electrically active and aggregates restored neurite outgrowth integrity and mitochondrial morphology. We identified significant transcriptomic changes after 24 h which were not present 7 days after wash-out. Our results suggest that testing short-term exposures in vitro may capture many acute effects which cells can overcome, missing adaptive processes, and long-term mechanisms. In addition, to study cellular resilience, cells were re-exposed to rotenone after wash-out and recovery period. Pre-exposed cells maintained higher metabolic activity than controls and presented a different expression pattern in genes previously shown to be altered by rotenone. NEF2L2, ATF4, and EAAC1 were downregulated upon single hit on day 14, but unchanged in pre-exposed aggregates. DAT and CASP3 were only altered after re-exposure to rotenone, while TYMS and MLF1IP were downregulated in both single-exposed and pre-exposed aggregates. In summary, our study shows that a human cell-based 3D model can be used to assess cellular adaptation, resilience, and long-term mechanisms relevant to neurodegenerative research.
AB - To date, most in vitro toxicity testing has focused on acute effects of compounds at high concentrations. This testing strategy does not reflect real-life exposures, which might contribute to long-term disease outcome. We used a 3D-human dopaminergic in vitro LUHMES cell line model to determine whether effects of short-term rotenone exposure (100 nM, 24 h) are permanent or reversible. A decrease in complex I activity, ATP, mitochondrial diameter, and neurite outgrowth were observed acutely. After compound removal, complex I activity was still inhibited; however, ATP levels were increased, cells were electrically active and aggregates restored neurite outgrowth integrity and mitochondrial morphology. We identified significant transcriptomic changes after 24 h which were not present 7 days after wash-out. Our results suggest that testing short-term exposures in vitro may capture many acute effects which cells can overcome, missing adaptive processes, and long-term mechanisms. In addition, to study cellular resilience, cells were re-exposed to rotenone after wash-out and recovery period. Pre-exposed cells maintained higher metabolic activity than controls and presented a different expression pattern in genes previously shown to be altered by rotenone. NEF2L2, ATF4, and EAAC1 were downregulated upon single hit on day 14, but unchanged in pre-exposed aggregates. DAT and CASP3 were only altered after re-exposure to rotenone, while TYMS and MLF1IP were downregulated in both single-exposed and pre-exposed aggregates. In summary, our study shows that a human cell-based 3D model can be used to assess cellular adaptation, resilience, and long-term mechanisms relevant to neurodegenerative research.
KW - 3D LUHMES
KW - Cellular defence
KW - Gene response
KW - Neurodegeneration
KW - Pesticide
KW - Recovery
KW - Resilience
KW - Rotenone
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U2 - 10.1007/s00204-018-2250-8
DO - 10.1007/s00204-018-2250-8
M3 - Article
C2 - 29955902
AN - SCOPUS:85049143580
VL - 92
SP - 2587
EP - 2606
JO - Archiv fur Toxikologie
JF - Archiv fur Toxikologie
SN - 0003-9446
IS - 8
ER -