Current Grant-funded Projects
Lateral view of a zebrafish developmentally-exposed to nonylphenol ethoxylate and aged to 30 days. Nile Red stain fluorescently labels the fat cells throughout the fish.

Metabolic Disruption by Common Surfactants

Currently funded through a K99/R00 award from NIEHS, this project aims to explore the potential metabolic disruption potential of alkylphenol and alcohol polyethoxylates, a group of common surfactants added to hard surface cleaners, detergents, paints, and other common consumer products. Our goals are to:
1) Identify potential metabolic health impacts (adiposity, altered growth) on developmentally-exposed zebrafish. 
2) Identify potential causal mechanisms through which these chemicals exert their effects on metabolic health.
3) Assess the relative contribution of these chemicals to metabolic impacts of environmental mixtures.

You can listen to a webinar that I gave on this topic here.

Metabolic Disruption Potential of Organic and Inorganic ​Contaminant Mixtures

Currently funded via an NIEHS P30 Center Pilot award through the Center for Urban Responses to Environmental Stressors. This project aims to explore the potential hormone receptor activation/inhibition and metabolic disruption of organic and inorganic pollutant mixtures relevant to Michigan. Our goals are to:

1) Characterize concentrations of inorganic pollutants in household dust and examine associations with organic pollutants/bioactivities. 
2) Assess adipocyte development and receptor disruption following exposure to select organic/inorganic contaminants and mixtures.
3) Assess adipocyte/adipose tissue development following exposure to select organic/inorganic contaminants and mixtures in zebrafish.
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Visualization of differentiated 3T3-L1 pre-adipocytes. Green = Nile Red lipid stain; blue = Hoechst DNA stain (cell number).

Other Projects/Broad Research Interests
Liquid crystal monomers (LCMs) are chemicals used in liquid crystal device (LCD) screens and have been shown to leach out and end up in both humans and the environment (sediment, household dust, etc.). 

Characterizing Liquid Crystal Monomer Toxicity

Started as a rotation project for Samantha Heldman, we have been working to characterize the endocrine toxicity and metabolic disruption potential of chemicals used in the LCD screens of your favorite devices. ​Samantha's first project profiled endocrine activity across diverse nuclear hormone receptors and examined the ability to promote fat cell development in a pre-adipocyte cell model. Our future projects intend to dig into mechanisms, metabolism of these chemicals, effects in a zebrafish model, and trying to better understand human exposure to these chemicals in the US. 

Metabolic Disruption by Environmental
​Contaminants and Mixtures

I'm interested in pursuing various other experiments to better characterize the metabolic disruption potential (ability to promote fat cell differentiation and proliferation) of environmental contaminants and mixtures. We've published previously on the ability of dozens of indoor contaminants and several types of environmental mixtures (e.g. indoor house dust and hydraulic fracturing wastewater) to promote both differentiation and proliferation in cell models. 

​We utilize cell-based adipocyte differentiation assays (pre-adipocyte and mesenchymal stem cell models), along with developmental exposures in zebrafish.

You can listen to a webinar I gave on this topic here.
Visualization of differentiated 3T3-L1 pre-adipocytes. Yellow = Nile Red lipid stain; blue = Hoechst DNA stain (cell number).
A natural gas well in Garfield County, Colorado, an extremely dense unconventional oil/natural gas production region.

 Identifying and Characterizing Endocrine Disrupting Chemicals and Mixtures

I have a great interest in pursuing novel endocrine disrupting chemicals and their mechanisms of action. 
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​This work has previously focused on novel environmental sources of endocrine disruptors like unconventional oil and gas production and residential household dust, and we have several novel projects actively developing in the lab!

We utilize cell-based reporter gene assays, cell-free receptor binding affinity assays, and adipogenesis bioassays to identify the molecular mechanisms and functional consequences of these chemicals and mixtures, as well as evaluating the causal chemicals responsible for these effects.

You can listen to a webinar I gave on this topic here.

Assessing Health Risks from Exposure to
​Environmental Contaminant Mixtures

I have great interest in pursuing endocrine disrupting chemical mixtures and their potential impacts on human/animal health.

​This work has previously focused on using whole environmental samples or extracts (unconventional oil and gas wastewater, municipal wastewater, residential household dust, silicone wristband extracts, and human serum). We work to measure biological activities (e.g. receptor activation or inhibition, adipocyte development) and associate these activities with human and animal health outcomes. We previously demonstrated that the extent of house dust-induced fat cell development was significantly associated with the BMI of residents in these homes.

​We utilize whole mixture testing in cell-based assays and animal models (primarily zebrafish) along with CRISPR to identify outcomes and understand mechanistically how mixtures act. We also collaborate with statisticians to better model mixtures and outcomes.​
Humans and animals are regularly exposed to complex mixtures of hundreds/thousands of chemicals, most of them not regulated, with uncertain health effects.