Discipline: Biological Sciences
Subcategory: Physiology and Health
Room: Exhibit Hall
Faith Smith - Fort Valley State University
Co-Author(s): Joshua Smith, Marie Delcy, and Celia Dodd
Introduced in the 1930s, Per-and polyfluoroalkyl substances (PFAS) have widely been used in industry for their waterproof properties in household products (carpets, clothing, non-stick pans, paints, etc.), personal care products (shampoos, dental floss, cosmetics), food packaging and fire extinguishing foams. Exposure to PFAS pose a major health concern due to their long biological half-lives. Human exposure can occur through consumption of contaminated drinking water, house dusts, food, and food packaging. Recently in vivo studies have shown that Perfluorooctane sulfonate (PFOS), a type of PFAS chemical, can be neurotoxic, specifically targeting dopaminergic neurons. However, the mechanism of neurotoxicity remains unknown. Oxidative stress is one possible mechanism for neurotoxicity. We hypothesize that PFOS exposure could lead to an increase in oxidative stress resulting in the damage to dopamine neurons. The goal of this study was to determine if exposure to PFOS increased reactive oxygen species, namely hydrogen peroxide.Caenorhabditis elegans is well characterized animal model useful because of its rapid life cycle. For this study, Larval stage 1 (L1) C.elegans were treated with 0 (control), 50, 100, 150 uM concentrations of PFOS and allowed to develop to larval stage 4 (L4) on NGM plates seeded with E. coli. Thirty L4 worms from each treatment plate were collected into wells of a 96-well plate and exposed to amplex red reaction mix. The Amplex™ Red reagent (10-acetyl-3,7-dihydroxyphenoxazine) was used to detect the presence of hydrogen peroxide (H2O2) in worms compared to a standard curve of known hydrogen peroxide concentrations (1-20 uM). The hydrogen peroxide present reacted with Amplex red reagent to produce a red fluorescent excitation product (resorfurin) that was measured spectrophotometrically.Our data collection indicates that hydrogen peroxide levels increased with exposure to the highest concentration of PFOS (150 uM) relative to control (0 uM). These findings contribute evidence to the hypothesis that PFAS exposure can increase oxidative stress which may lead to neurotoxicity. Future studies will examine if PFOS increases the production of other reactive species including superoxide. In conclusion, this study further reiterates the need for limiting exposure to these PFAS chemicals.
Funder Acknowledgement(s): NSF/HBCU-UP, targeted infusion project
Faculty Advisor: Dr. Celia Dodd, firstname.lastname@example.org
Role: I completed all the requirements for this project, including maintaining worms, collecting data, treating worms, making NGM plates, etc.