Title
Adverse outcome pathways: Opportunities, limitations and open questions
Author
Leist, M.
Ghallab, A.
Graepel, R.
Marchan, R.
Hassan, R.
Bennekou, S.H.
Limonciel, A.
Vinken, M.
Schildknecht, S.
Waldmann, T.
Danen, E.
van Ravenzwaay, B.
Kamp, H.
Gardner, I.
Godoy, P.
Bois, F.Y.
Braeuning, A.
Reif, R.
Oesch, F.
Drasdo, D.
Höhme, S.
Schwarz, M.
Hartung, T.
Braunbeck, T.
Beltman, J.
Vrieling, H.
Sanz, F.
Forsby, A.
Gadaleta, D.
Fisher, C.
Kelm, J.
Fluri, D.
Ecker, G.
Zdrazil, B.
Terron, A.
Jennings, P.
van der Burg, B.
Dooley, S.
Meijer, A.H.
Willighagen, E.
Martens, M.
Evelo, C.
Mombelli, E.
Taboureau, O.
Mantovani, A.
Hardy, B.
Koch, B.
Escher, S.
van Thriel, C.
Cadenas, C.
Kroese, D.
van de Water, B.
Hengstler, J.G.
Publication year
2017
Abstract
Adverse outcome pathways (AOPs) are a recent toxicological construct that connects, in a formalized, transparent and quality-controlled way, mechanistic information to apical endpoints for regulatory purposes. AOP links a molecular initiating event (MIE) to the adverse outcome (AO) via key events (KE), in a way specified by key event relationships (KER). Although this approach to formalize mechanistic toxicological information only started in 2010, over 200 AOPs have already been established. At this stage, new requirements arise, such as the need for harmonization and re-assessment, for continuous updating, as well as for alerting about pitfalls, misuses and limits of applicability. In this review, the history of the AOP concept and its most prominent strengths are discussed, including the advantages of a formalized approach, the systematic collection of weight of evidence, the linkage of mechanisms to apical end points, the examination of the plausibility of epidemiological data, the identification of critical knowledge gaps and the design of mechanistic test methods. To prepare the ground for a broadened and appropriate use of AOPs, some widespread misconceptions are explained. Moreover, potential weaknesses and shortcomings of the current AOP rule set are addressed (1) to facilitate the discussion on its further evolution and (2) to better define appropriate vs. less suitable application areas. Exemplary toxicological studies are presented to discuss the linearity assumptions of AOP, the management of event modifiers and compensatory mechanisms, and whether a separation of toxicodynamics from toxicokinetics including metabolism is possible in the framework of pathway plasticity. Suggestions on how to compromise between different needs of AOP stakeholders have been added. A clear definition of open questions and limitations is provided to encourage further progress in the field. © 2017, Springer-Verlag GmbH Germany.
Subject
Life
RAPID - Risk Analysis for Products in Development
ELSS - Earth, Life and Social Sciences
Biomedical Innovation
Biology
Healthy Living
Binning of events
CCl4
Computational toxicology
Interspecies extrapolation
Liver fibrosis
Metabolism
Multi-scale integration
Multiple hit events
Paracetamol
Pathway unidirectionality
Prioritization of compounds
Proof of non-toxicity
Regulatory toxicology
Systems biology
Tumor promotion
Vinyl acetate
Adverse outcome
Adverse outcome pathway
Ecotoxicology
Epidemiological data
Human
Nonhuman
Plasticity
Risk assessment
Signal transduction
Toxicity assay
Toxicokinetics
To reference this document use:
http://resolver.tudelft.nl/uuid:12b5a0d9-939d-4bd0-9760-54b214f15cf1
DOI
https://doi.org/10.1007/s00204-017-2045-3
TNO identifier
782466
ISSN
0340-5761
Source
Archives of Toxicology, 91 (11), 3477-3505
Document type
article