Cell-Free Neurochemical Screening Assays to Predict Adverse Effects in Mammals, Fish, and BirdsEPA Grant Number: R835170
Title: Cell-Free Neurochemical Screening Assays to Predict Adverse Effects in Mammals, Fish, and Birds
Investigators: Basu, Niladri
Current Investigators: Basu, Niladri , Head, Jessica Anne , Murphy, Cheryl A. , Neitzel, Richard L.
Institution: University of Michigan
EPA Project Officer: Ramasamy, Santhini
Project Period: September 1, 2012 through August 31, 2015 (Extended to August 31, 2017)
Project Amount: $1,199,222
RFA: Developing High-Throughput Assays for Predictive Modeling of Reproductive and Developmental Toxicity Modulated Through the Endocrine System or Pertinent Pathways in Humans and Species Relevant to Ecological Risk Assessment (2011) RFA Text | Recipients Lists
Research Category: Computational Toxicology , Endocrine Disruptors , Health , Ecosystems , Safer Chemicals
The overall objective of this proposal is to advance an existing in vitro, cell-free neurochemical screening assay platform, and model data outputs to predict adverse, individual-level reproductive effects associated with toxicant exposure in mammalian, fish, and avian wildlife. The overall hypothesis is that several environmental toxicants will emerge to interact with and disrupt the function of neurotransmitter receptors, enzymes and transporters that have critical roles in vertebrate reproduction.
We will study 60 toxicants (various metals, pharmaceuticals, personal care products, polycyclic aromatic hydrocarbons, halogenated aromatics, pesticides, real-world environmental mixtures), 16 neurochemicals (receptors, enzymes, transporters) important in the neurotransmission of dopamine, GABA, glutamate, and acetylcholine, and 20 organisms (2-3 different freshwater fish, marine fish, terrestrial mammals, marine mammals, Arctic marine mammals, domestic birds, piscivorous birds, songbirds, rats and humans). All assays are cell-free, and will be performed in 96-well microplates and are thus capable of being performed in a “high-throughput” manner. We have published widely on our approach, and here we adapt our screening platform to address the goals of the present RFA and mirror the U.S. EPA‟s ToxCast program. In terms of research approach, first, a single concentration (50μM or 0.5mg/ml) of each toxicant (n=60) will be evaluated in triplicate in each cell-free in vitro assay (n=16) for each species (n=20), thus resulting in 19,200 mean datapoints, plus many more after various controls are accounted for. Second, 120 toxicant-assay pairs that show most significant changes will then be further evaluated in each organism to derive concentration-response relationships. Third, a series of statistical and simulation models will aim to integrate results from cell-free assays to reproductive outcomes at the individual-level, which is an apical endpoint that can be used to predict population-level impacts.
This work will result in the establishment of a high-throughput screening assay that can be used to predict reproductive impairment across multiple ecologically relevant species (birds, fish, mammals). Resources exist to adapt this platform to screen 1,000s of toxicants. It will generate important data on several toxicant classes (incl. real-world mixtures) that are of ecological relevance. Data outputs will be modeled to predict adverse outcomes at the individual level. Several publications, presentations and student dissertations will be produced.