2015 Progress Report: Organotypic Model of Testis as a Platform for Adverse Outcomes Pathway Assessment of Engineered Nanomaterials

EPA Grant Number: R835738C004
Subproject: this is subproject number 004 , established and managed by the Center Director under grant R835738
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: Predictive Toxicology Center for Organotypic Cultures and Assessment of AOPs for Engineered Nanomaterials
Center Director: Faustman, Elaine
Title: Organotypic Model of Testis as a Platform for Adverse Outcomes Pathway Assessment of Engineered Nanomaterials
Investigators: Faustman, Elaine
Institution: University of Washington
EPA Project Officer: Klieforth, Barbara I
Project Period: December 1, 2014 through November 30, 2018
Project Period Covered by this Report: December 1, 2014 through November 30,2015
Project Amount: Refer to main center abstract for funding details.
RFA: Organotypic Culture Models for Predictive Toxicology Center (2013) RFA Text |  Recipients Lists
Research Category: Safer Chemicals , Health , Human Health

Objective:

The overall goal of this project is to utilize an organotypic in vitro model of testicular development to evaluate the male reproductive toxicity of Engineered Nanomaterials (ENM) using an adverse outcome pathway (AOP) framework. We will use three-dimensional in vitro testicular co-cultures that have been shown to capture key processes of male reproductive development in order to evaluate the potential for ENMs to alter these processes. We will measure the ability of ENMs to alter cellular differentiation and tissue maturation with a focus on the roles of developmental timing and genetics in influencing susceptibility. We also will explore the role of oxidative stress and inflammation pathways in mediating ENM-induced perturbation of development. Finally, we will use toxicokinetic and dynamic models to integrate in vitro our findings into an AOP framework. 

Progress Summary:

In order to fulfill our objective of incorporating developmental and genetic susceptibility into metal and ENM evaluation, we have constructed a detailed timeline relating testicular development and hormonal changes across rats, mice, and humans.  This substantiates our recent publication, Wegner, et al., 2015, which was featured on the cover of Reproductive Toxicology. In this publication, we conducted a quantitative pathway analysis of gene expression over time to summarize key pathways that occur during development. This approach has provided a framework for identifying and quantifying the perturbations of normal developmental signaling dynamics caused by environmental factors.

Our previous research has shown that these systems can distinguish between developmentally toxic and developmentally nontoxic phthalates by assessing changes in transcriptomic profiles (Yu, et al., 2009).  This year, we have completed the evaluation of more than 80 chemicals for reproductive and developmental toxicity and are using the results from our co-culture system to determine the value of specific endpoints, cytotoxicity, changes in cytokine expression, and testosterone perturbation for the predictive profiles for these agents.  The cytotoxicity results were compared to results from the ToxCast and ToxRef databases to identify known reproductive and developmental toxicants.  The Benchmark Concentration (BMC) that produced cytotoxicity in 10% of the samples (BMC10) was calculated using EPA’s Benchmark Dose modeling approach.

We also have demonstrated that the testis co-culture system can mount biologically relevant responses following chemical exposure.  For example, we have shown that the system can identify chemicals that perturb testosterone production in a dose-dependent manner.  We measured testosterone production in our co-culture system at 24 and 72 hours. As the dosages of sodium arsenite, crizotinib, nicotine, valproic acid, and vinclozolin were increased, testosterone production was perturbed. For these chemicals, cytotoxicity and testosterone perturbation occurred at some overlapping doses. Vinclozalin, a fungicide, significantly modified testosterone production at concentrations that were not cytotoxic. 

The co-culture system can successfully generate a proinflammatory cytokine response following exposure to phthalates and other compounds (data not shown).  Increases in proinflammatory cytokines were observed at 2, 8, and 24 hours following phthalate exposure. Another key focus for this year, related to immune responses, has been the detection of resident macrophages in the testis co-culture (data not shown). These previous results have provided a strong foundation of applications for assessment of lifestage specific reproductive and developmental toxicity of additional metal and ENM compounds. 

Future Activities:

Our progress to date has focused on expanding the applications of our testis co-culture system to answer this project’s research questions. The next steps with this work will expand the chemicals tested to include more metals and ENMs. As more biological responses are observed, such as oxidative stress and inflammation, we will be able to better characterize lifestage specific AOPs for reproductive and developmental toxicity. 


Journal Articles on this Report : 3 Displayed | Download in RIS Format

Other subproject views: All 35 publications 6 publications in selected types All 6 journal articles
Other center views: All 134 publications 39 publications in selected types All 38 journal articles
Type Citation Sub Project Document Sources
Journal Article Harris S, Hermsen SA, Yu X, Hong SW, Faustman EM. Comparison of toxicogenomic responses to phthalate ester exposure in an organotypic testis co-culture model and responses observed in vivo. Reproductive Toxicology 2015;58:149-159. R835738 (2016)
R835738 (2017)
R835738 (2018)
R835738C004 (2015)
R835738C004 (2017)
R834514 (Final)
R834514C003 (2015)
R834514C003 (Final)
  • Full-text from PubMed
  • Abstract from PubMed
  • Associated PubMed link
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect-Full Text PDF
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  • Journal Article Harris S, Wegner S, Hong SW, Faustman EM. Phthalate metabolism and kinetics in an in vitro model of testis development. Toxicology in Vitro 2016;32:123-131. R835738 (2016)
    R835738 (2017)
    R835738 (2018)
    R835738C004 (2015)
    R835738C004 (2016)
    R835738C004 (2017)
    R834514 (Final)
    R834514C003 (Final)
  • Full-text from PubMed
  • Abstract from PubMed
  • Associated PubMed link
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect-Full Text PDF
    Exit
  • Journal Article Wegner SH, Yu X, Pacheco Shubin S, Griffith WC, Faustman EM. Stage-specific signaling pathways during murine testis development and spermatogenesis: a pathway-based analysis to quantify developmental dynamics. Reproductive Toxicology 2015;51:31-39. R835738 (2016)
    R835738 (2017)
    R835738 (2018)
    R835738C004 (2015)
    R835738C004 (2017)
    R834514 (2015)
    R834514 (Final)
    R834514C003 (2015)
    R834514C003 (Final)
  • Full-text from PubMed
  • Abstract from PubMed
  • Associated PubMed link
  • Full-text: ScienceDirect-Full Text HTML
    Exit
  • Abstract: ScienceDirect-Abstract
    Exit
  • Other: ScienceDirect-Full Text PDF
    Exit
  • Supplemental Keywords:

    reproductive and developmental toxicity, chemical screening, testicular development, in vitro model 

    Relevant Websites:

    The Predictive Toxicology Center (PTC) for Organotypic Cultures Exit

    Progress and Final Reports:

    Original Abstract
  • 2016 Progress Report
  • 2017 Progress Report
  • Final

  • Main Center Abstract and Reports:

    R835738    Predictive Toxicology Center for Organotypic Cultures and Assessment of AOPs for Engineered Nanomaterials

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R835738C001 Airway Epithelium Organotypic Culture as a Platform for Adverse Outcomes Pathway Assessment of Engineered Nanomaterials
    R835738C002 Organotypic Model of Human Kidney as a Platform for Adverse Outcomes Pathway Assessment of Engineered Nanomaterials
    R835738C003 Organotypic Models of Mammalian Liver as a Platform for Adverse Outcomes Pathway Assessment of Engineered Nanomaterials
    R835738C004 Organotypic Model of Testis as a Platform for Adverse Outcomes Pathway Assessment of Engineered Nanomaterials
    R835738C005 Integrating Liver, Kidney and Testis Nanomaterial Toxicity using the Adverse Outcome Pathway Approach