Please join the Environmental Change Initiative for a virtual seminar presented by Amy Rand, Assistant Professor at Carleton University, Canada.

Her seminar is on "Contaminant biotransformation and activation: Identifying the enzymes, organisms, and mechanisms that contribute to toxicity."

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Abstract: A complicating factor in environmental contaminant research is that many commercial and industrial compounds are metabolically labile, transforming to produce environmentally persistent and/or bioactive compounds. Therefore, the sources of exposure to environmental contaminants can stem from direct use, but also indirectly, from metabolically active precursor compounds. While contaminant biotransformation pathways have been elucidated in several organisms, we address the following questions: which enzymes contribute to contaminant bioactivation? What is the propensity for metabolism to occur in extrahepatic systems? Can the organism’s response to toxicant exposure be measured by a targeted lipidomic platform?

This talk will focus on three of our research projects that address these questions. The first characterizes the oxidative enzymes responsible for transforming a class of polyfluoroalkyl substances (PFASs), the fluorotelomer alcohols (FTOHs), into persistent pollutants. For this, we used a variety of in vitro tools to characterize the contribution of six major xenobiotic enzymes towards catalyzing FTOH oxidation. The second covers the development of a Caenorhabditis elegans model to measure oxidative stress, pairing traditional methods with a targeted LC- MS/MS method to measure over 60 signaling lipids involved in numerous physiological and pathological processes. The third examines the gut microbiome as an important site of biotransformation, using a PFAS surfactant as a representative metabolically labile contaminant. Capturing biotransformation within the gut microbiome is important given the potential to increase circulating levels of bioactive metabolites, which cannot be elucidated by traditional hepatic metabolic studies. We highlight the challenge of predicting risk of emerging pollutants due to metabolism; knowledge in this area will increase understanding about an individual’s susceptibility to adverse outcomes stemming from toxicant exposure.

Bio: Amy Rand has broad research interests in exposure science, environmental chemistry, and toxicology. Current research studies include developing animal models to study mechanisms of cell stress and lipid signaling, examining the metabolic fate of per- and polyfluoroalkyl substances (PFAS), and elucidating the many routes of human and wildlife exposure to environmental pollutants. Before joining Carleton in 2017, she was a postdoctoral fellow at University of California, Davis. There, she completed a T32 Fellowship Program in Oncogenic Signals & Chromosome Biology funded by the National Institute of Health to characterize a lipid signaling pathway that enhances angiogenesis, the formation of new blood vessels. Prior to her postdoc, she completed her Ph.D. at the University of Toronto in Environmental Chemistry, studying the transformation and fate of PFAS.