brynn-helm@uiowa.edu
Mentor: Aloysius Klingelhutz, Ph.D.
Lab Room: 3-615A BSB
Lab Phone: 319-335-8499

Polychlorinated biphenyls (PCBs) are highly stable, bioaccumulating global environmental toxins that were used in transformers, capacitors, pesticides, and additives in paints and plastics prior to their ban in the 1970s. PCBs are oxidized by the hepatic cytochrome P450 (CYP450) enzymes into their hydroxylated forms that are easier to excrete. Studies have shown that both parental PCB compounds and their hydroxylated forms are toxic to the liver. Exposure to PCBs has been linked to liver dysfunction and nonalcoholic fatty liver disease (NAFLD), which is also characterized by the accumulation of damaged mitochondria. Damaged mitochondria are unable to make enough energy for hepatocytes to function properly. The focus of my studies is how lower-chlorinated PCBs contribute to hepatotoxicity. Lower-chlorinated PCBs are more likely to spread in the air and are more easily metabolized than their higher-chlorinated counterparts. I aim to use 2D and 3D liver cell culture models to assess how lower-chlorinated PCBs affect mitochondrial function.

Francoise A. Gourronc, Brynn K. Helm, Larry W. Robertson, Michael S. Chimenti, Hans Joachim-Lehmler, James A. Ankrum, Aloysius J. Klingelhutz, Transcriptome sequencing of 3,3′,4,4′,5-Pentachlorobiphenyl (PCB126)-treated human preadipocytes demonstrates progressive changes in pathways associated with inflammation and diabetes., Toxicology in Vitro, Volume 83, 2022, 105396, ISSN 0887-2333, https://doi.org/10.1016/j.tiv.2022.105396. (https://www.sciencedirect.com/science/article/pii/S0887233322000935)