Dr Yun Yun Gong, Professor in International Food Safety

School of Food Science and Nutrition, University of Leeds, Leeds, UK

Lecture for Students and Teachers

Title: Impact of individual and mixtures of mycotoxins and persistent organochloride pesticides on reproduction - in vitro investigations

Time: May.30, 2019, 9:00

Place: Room 506, Wenhua Building.

Introduction to Dr Yun Yun Gong:

Dr Yun Yun Gong is a professor in international food safety in the University of Leeds. She has a PhD degree in Food toxicology and started her research career at the University of Leeds in 2000. She has a strong research interest on dietary exposure to toxic chemicals (especially mycotoxins) and their impact on human health outcomes e.g. child stunting, cancer and reproductive health. More recently this is expanded to the detection and prevention of food born toxins exposure in high risk populations. Her other research interests include understanding the relationship between diet and cancer, and conducting food safety risk assessment at a global perspective. She collaborates with multi-disciplinary expertise from agriculture, plant science, health science and food safety policy makers. Her research was funded by the Bill and Gates Melinda Foundation, the Royal Society UK, the NIEHS in the US, etc. Dr Gong was a Scientific Visitor at the International Agency for Research on Cancer (IARC) in 2013 and a working group member evaluating aflatoxin and human health for the WHO/IARC. She is a working group member for the European Food Safety Authority (EFSA) and an advisory role in China National Center for Food Safety and Risk Assessment (CFSA) on mycotoxin risk assessment.

Abstract:

Environmental and food-borne toxins e.g. mycotoxins and persistent organochloride pesticides (POPs) have been suggested to have endocrine disrupting effects. However, the reproductive toxicological effect of both individual and mixtures of these toxins are little understood. This research explores various in vitro cellular models, namely the reporter gene assay (RGA) using MMV-Luc, cytotoxicity and hormonal alteration in MA-10 Leydig cell line and BeWo placental cell lines to evaluate the toxicological effects on reproduction by individual and mixtures of selected mycotoxins zearalenone (ZEN), α-zearalenol (α-ZOL), β-zearalenol (β-ZOL), deoxynivalenol (DON) and ochratoxin A (OTA) and POPs 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (DDT) and its metabolite 1, 1, 1-trichloro-2,2-bis (p-chlorophenyl)-ethane (DDE). In the RGA study, ZEN and α- ZOL at biologically relevant concentrations induced oestrogen receptor (ER) transcriptional response (75% - 85%) similar to the response mediated by 10 nM of 17β-oestradiol (E2). Co-exposure of single mycotoxins with clinically relevant concentrations of E2 (0.05 nM or 10 nM) had stimulatory or inhibitory effect on E2-mediated ER transcriptional response depending on dose whereas mixtures of equimolar concentration (50 µM) of DDT and DDE with E2 at similar doses completely abolished ER response. Among single toxins, DON and OTA were significantly cytotoxic to both MA-10 and BeWo cell lines. In the endocrine function, ZEN and its metabolites elevated progesterone production, but inhibited testosterone level in MA-10 cells whereas they had no effect on progesterone levels in BeWo cells, but significantly increased E2 production. All the tested mycotoxins and POPs significantly inhibited the production of beta-human chorionic gonadotropin (β-hCG) in BeWo placental cells. The effects of binary mycotoxin and POPs combinations on cell viability and hormone production showed synergistic, additive or antagonistic effects depending on the cell model, tested concentrations or mixture. Overall, this study provides the first comprehensive evidence that exposure to mycotoxins and/or POPs, individually or in combination, could have adverse effects on reproduction and development through multiple mechanisms.

(School of Food and Biological Engineering)