Grantee Research Project Results
2017 Progress Report: Toxicogenomics-based Mechanistic Multimedia Exposure Assessment and Child Development
EPA Grant Number: R836155C002Subproject: this is subproject number 002 , established and managed by the Center Director under grant R836155
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
Center: Center for Research on Early Childhood Exposure and Development in Puerto Rico
Center Director: Alshawabkeh, Akram
Title: Toxicogenomics-based Mechanistic Multimedia Exposure Assessment and Child Development
Investigators: Gu, April Z , Vulpe, Christopher D. , MacIntosh, Helen Suh , Weisman, David , Manjourides, Justin , Fasullo, Michael
Institution: Northeastern University , University of Massachusetts - Boston , The State University of New York Polytechnic Institute , University of California - Berkeley
Current Institution: Northeastern University , The State University of New York Polytechnic Institute , University of California - Berkeley , University of Massachusetts - Boston
EPA Project Officer: Hahn, Intaek
Project Period: September 1, 2015 through August 31, 2019 (Extended to August 31, 2021)
Project Period Covered by this Report: September 1, 2016 through August 31,2017
RFA: Children's Environmental Health and Disease Prevention Research Centers (2014) RFA Text | Recipients Lists
Research Category: Human Health , Children's Health
Objective:
Project 2 employs novel in vitro, high throughput screening (HTS) assays to yield new toxicity information needed to reveal the impacts of exposure to complex pollutant mixtures on pathways relevant to neonatal and early childhood development. Significant challenges remain in understanding the complex risks that pollutant mixtures and their metabolites pose for human health. These challenges motivate a new paradigm for toxicity evaluation that is based on an in vitro mechanistic and genetic pathway-based approach that allows combinations of exposures and outcomes to be tested comprehensively yet feasibly. To address this need, researchers have developed an approach that uses in vitro HTS to measure translational changes in targeted genetic pathways occurring in response to pollutants and pollutant mixtures. Importantly, these pollutants and mixtures are drawn directly from environmental sources, such as water and air, and also from biological matrices like urine. They then are passed through in vitro preparations of human and non-human cells, where researchers measure biomarkers of oxidative stress, DNA damage, and inflammation. These pathways and biomarkers were selected based on their established association with CRECE-relevant neonatal and early childhood health outcomes, and because the biomarkers are found at measurable concentrations in the urine and sera of exposed individuals. Through this approach, researchers are able to provide pathway- and sample-specific fingerprints of pollutant exposures and their effects that can inform environmental epidemiological studies and even be used themselves as biomarkers of exposure in these studies. Through close collaboration with CRECE’s other two projects, this project will inform epidemiological studies of our cohort of 600 Puerto Rican children. These studies leverage data and infrastructure established under PROTECT, a highly productive NIEHS-funded pregnancy study of a cohort of 1800 pregnant women from Puerto Rico’s northern coast. This project will provide its HTS findings and exposure biomarker measures to Projects 1 and 3, thus allowing those projects to perform health effect analyses for pollutant mixtures identified as toxic by the HTS, and to examine the association of exposure biomarkers with neonatal and early childhood health outcomes.
Progress Summary:
Toxicity of Pollutant Mixtures in Puerto Rican Drinking Water: Researchers have analyzed 15 initial ground and well water samples from PR study sites. In order to identify potential toxicity nature and levels and to reveal the potential causal agents, researchers have conducted parallel toxicity assessment and chemical analysis. For toxicity evaluation, researchers performed cytotoxicity and HTS pathway-specific toxicogenomics assays that target various stress response pathways. For chemical characterization of the water samples, in collaboration with other participants, researchers conducted untargeted analysis, metals analysis (13 different metals), and targeted analysis of volatile disinfection byproducts (DBPs) and di(2-ethylhexyl)phthalate (DEHP).
Researchers have conducted initial testing with tap water samples to refine assays and protocols, and to quantify the robustness, reproducibility, and sensitivity for tap water samples analysis. The results showed that the assay is sensitive enough to reveal the potential toxicity of tap water at up to 100-500x enrichment factor. Researchers also have established an initial statistical analysis approach for all toxicity data analysis and correlation analysis.
The results demonstrate that the HTS in vitro quantitative toxicogenomics assay is effective for evaluating and revealing the water toxicity level and profile changes among different drinking water sources. The results also demonstrate that the assay allows investigation of the background toxicity level and profiles in PR drinking water sources including groundwater, well water, and tap water. The quantitative measures of pathway-specific and chemical-specific biomarkers of exposure to water contaminants, including CECs, metals, and associated toxicity fingerprints, were obtained for each water sample using HTS assays for oxidative stress, DNA damage, protein stress, chemical stress, and inflammation. Comparison and correlation analysis of the quantitative toxicity profiling index (PELIs) with results from untargeted organics analysis, as well as metals analysis, revealed potential association or casual relationships. For example, samples from the MIT site that exhibited the highest molecular stress-related toxicity level also had the highest number of hits of detected toxic chemicals from untargeted analysis. Another site-POL, which had detected toxicity related to oxidative stress and chemical stress, had higher level of As and Sr detected.
Toxicity of Puerto Rican Air Pollutant Mixtures: The PR team is working with Project 1 to establish protocols for air sample collection and characterization. In collaboration with Professor Dan Li (FuDan University, China), the team is working on finalizing the protocols for toxicity analysis. Researchers are conducting preliminary evaluation of air sample extraction methods for organic pollutants mixtures and metals. The sample-specific impacts of PM2.5 components will be assessed using HTS assays for oxidative stress, DNA damage, and inflammation, with results reported as quantitative pathway- and chemical-specific biomarker measures and toxicity fingerprints.
Toxicity of Chemicals and Metabolites Found in Urine: Researchers have evaluated two urine sample extraction pretreatment techniques, comparing their recovery rate and reproducibility. The two techniques include a conventional solid phase extraction (SPE) method, and another newly developed tea bag equilibrium extraction method by Dr. Roger Giese’s lab at Northeastern University. The customized composite adsorption media in the tea bag is expected to trap a wider range of chemicals in the urine than a commercially available SPE cartridge. The preliminary results showed much improved recovery rate and reproducibility with the tea bag method, which is adopted by this study.
Researchers have conducted initial testing with urine samples to refine assay protocols and quantify the robustness, reproducibility, and sensitivity for tap water samples analysis. The results showed that the assay is sensitive enough to reveal the potential toxicity of a urine sample at original concentration 1X.
Future Activities:
The overall goal of the next reporting period is to obtain and finish the experimental and data analysis of up to 30 each of the water, urine, and air samples from PR sites as described in the goals. Researchers also will collaborate with co-PIs and consultants with bioinformatics expertise to establish the initial framework and platform for data collection, storage, and exploration of up to two different data correlation and clustering analyses. Prior to the field sample mixture toxicity analysis, experimental protocols for sampling, sample pretreatment, and pollutants extraction will be further refined and optimized to ensure the reproducibility, robustness, and reliability of the techniques and resulting data.
Journal Articles:
No journal articles submitted with this report: View all 11 publications for this subprojectSupplemental Keywords:
toxicogenomics, environmental exposure, biomarkers, pathway-specific effectsProgress and Final Reports:
Original AbstractMain Center Abstract and Reports:
R836155 Center for Research on Early Childhood Exposure and Development in Puerto Rico Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
R836155C001 Air Pollution Impacts on Neonatal and Early Childhood Development
R836155C002 Toxicogenomics-based Mechanistic Multimedia Exposure Assessment and Child Development
R836155C003 Biomarker Epidemiology of In Utero Environmental Exposures and Child Development
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
1 journal articles for this subproject
Main Center: R836155
68 publications for this center
47 journal articles for this center