Peter van den Hurk, PhD
Associate Professor, Biological Sciences
Clemson University
He/Him/His
Description: Over the last decades, more and more examples have been discovered of unexpected differences in the expression of phase 2 detoxification enzymes in vertebrate species, not only in UDP-glucuronosyltransferases but also in sulfotransferases. These enzymes are involved in metabolizing poorly water-soluble substrates, facilitating the excretion of the toxicant. To further investigate species differences in marine fish taxa, a variety of species was evaluated for the activity of sulfation and glucuronidation enzymes. Primitive fish species like hagfish and lamprey appeared to have no glucuronidation activity towards phenolic substrates, while activity in sharks and rays was much lower than in bony fishes. This would indicate that the earliest vertebrates had no glucuronidation capacity, and that the array of glucuronosyltransferases that is known in more modern fish species and other vertebrates has evolved later. However, there are examples of other vertebrates that also don’t have glucuronidation capability towards phenolic substrates. We performed experiments to demonstrate that snake species lack phenol-type glucuronidation activity compared to other reptilians. This makes certain chemicals extremely toxic for snakes, and is used for management of invasive snake species, like the brown treesnake on Guam. In addition, even among the mammals it has been known that felines lack phenol-type glucuronidation activity, which makes them extremely sensitive to compounds like acetaminophen. Our latest research showed that also among bird species a large variety in glucuronosyltransferase enzymes is found. The explanation for this diverse expression of glucuronosyltransferases in different vertebrate taxa is probably a combination of phylogenetic origins and the degradation of genomic information in genes that are not essential in obligate carnivores like cats, snakes and birds of prey. This differentiated expression of glucuronosyltransferases can explain observed differences in sensitivity towards phenol-type pollutants in environmentally relevant species.
About the Speaker: Peter van den Hurk is an Associate Professor in the department of Biological Sciences at Clemson University and serves as Program Coordinator for the Graduate Program of Environmental Toxicology. He earned BS degrees in Biology and Geology at the University of Groningen (Netherlands) and received an MS degree in zoology/marine biology at the University of Amsterdam in 1988. He then worked for 7 years for two environmental consultancy companies in the Netherlands, mostly on sediment toxicity studies, before he moved to the US to pursue a doctoral degree in Environmental Sciences at the School of Marine Science at the College of William and Mary in Virginia. His dissertation studies investigated the interactive toxicological effects of cadmium and benzo[a]pyrene in an estuarine fish species. During a postdoc position in the Department of Medicinal Chemistry at the College of Pharmacy, University of Florida, he further specialized in mixture toxicology and detoxification pathways of organic pollutants. His current research program includes studies on the function, species differences and evolution of detoxification enzymes, application of biomarkers in environmental problem areas, the toxicity of microplastics and tire wear particles in estuarine and aquatic systems, and the behavioral and biochemical effects of pharmaceuticals in fish. Dr. van den Hurk teaches undergraduate and graduate courses in the field of environmental toxicology and has supervised a variety of undergraduate, MS and PhD students. He has published 50+ scientific papers and reports, presented his work at numerous national and international meetings, and managed >$1m in grant money during his academic career. He has served on NSF and NIH grant review panels and is an active member of the Society of Toxicology and the Society of Environmental Toxicology and Chemistry. He is currently member of the editorial board of Environmental Toxicology and Chemistry and has served on the boards of regional chapters of both SOT and SETAC.
Friday, September 27, 2024, 12:00-1:15pm Eastern
Field Auditorium, Room 1112, Grainger Hall (9 Circuit Drive, Durham, NC)
This seminar will also be presented live via Panopto. Click HERE for the livestream.