IN VITRO RESILIENCE AND NANOTOXICITY IN 3D BRAIN MODELS

Resilience;Recovery;Neurotoxicity;3D;In Vitro;Toxicology;Rotenone;Glyphosate;Wash-out;Repeated-dose;Nanotoxicity;Environmental Health & Engineering

Harris, Georgina AlexandraFallin, Daniele ;

Johns Hopkins University

关键词: Resilience;    Recovery;    Neurotoxicity;    3D;    In Vitro;    Toxicology;    Rotenone;    Glyphosate;    Wash-out;    Repeated-dose;    Nanotoxicity;    Environmental Health & Engineering;   

Others  :  https://jscholarship.library.jhu.edu/bitstream/handle/1774.2/60969/HARRIS-DISSERTATION-2018.pdf?sequence=1&isAllowed=n

瑞士|英语

来源: JOHNS HOPKINS DSpace Repository

【 摘 要 】

Current neurotoxicity testing does not meet the needs to protect human health from potential neurotoxicants. The increase in incidence of neurological disorders has shown that environmental exposures may pose a risk in conjunction with genetic factors. Pesticide exposure and aging are associated with increased Parkinson’s disease (PD) risk. To date, in vitro research focuses on apical endpoints from high-dose acute exposures. We propose to study cellular recovery and resilience in vitro, to challenge current acute toxicity testing and question (a) whether dopaminergic cells can recover from low-dose exposures and (b) how they respond to a subsequent toxicant hit. To address the current needs, we developed and characterized an in vitro human dopaminergic 3D brain model using LUHMES (Lund Human Mesencephalic cell line). Taking advantage of the fact that our model is cultured in suspension, we analyzed not only acute but also delayed response to the pesticide rotenone after compound withdrawal and 7 days recovery. Rotenone quantification demonstrated it was effectively removed from media after wash-out. We further assessed viability after second exposures to test our resilience hypothesis. Molecular and functional assays were used to assess toxicity and recover. Dopaminergic neurons were able to recover functionally (neurite outgrowth and electrical acitivty) from low-dose acute rotenone effects, however other endpoints (complex I inhibition, gene expression) were permanently altered and pre-exposed cells were resilient to a second hit indicating long-term molecular memory after wash-out. Repeated low-dose exposures to rotenone upregulated PD-related genes.Finally, 3D LUHMES and iPSC-derived BrainSphere model ware applied to study internalization and toxicity of nano-delivery particles (AuSC, AuPEG and PLA). Effects on viability, mitochondrial membrane potential and oxidative response genes were observed. Our results present a different approach to studying toxicity in vitro, with the use of 3D models and compound wash-out to better understand whether acute effects are reversible (more similar to in vivo exposures). Genetic or epigenetic factors could lead to altered recovery and drive disease development. Furthermore, advances in nanotechnology require new testing strategies to assess the safety for novel drug delivery systems.