CONICET | Buscador de Institutos y Recursos Humanos

Placental barrier regulates maternal-fetal interchange protecting the baby from damage caused by substancesfound in the uterine environment or circulating in the vascular system. Organophosphate (OP) pesticides are aparamount group of environmental pollutants used in intensive agriculture for protection against diseases andpests. While many studies have reported an increased risk of pregnancy alterations in pregnant women exposedto OPs, few have analyzed the effects caused by these pesticides in the placenta.Herein, we evaluated the effects of chlorpyrifos (CPF), one of the most widely used OP insecticides, on human placentausing in vitro and ex vivo exposure models. Villous cytotrophoblast cells isolated from normal human termplacentas maintained their cell viability, differentiated into syncytiotrophoblast-like structures, and increased theexpression of β-hCG, ABCG2, and P-gp in the presence of CPF at concentrations of 10 to 100 μM. The same doses ofCPF induced marked changes in chorionic villi samples. Indeed, CPF exposure increased stroma cell apoptosis, alteredvilli matrix composition, basement membrane thickness, and trophoblastic layer integrity.Histomorphological and ultrastructural alterations are compatible with those found in placentas where maternal-placentainjury is chronic and able to impair the placental barrier function and nutrient transport from motherto the fetus.Our study shows that placental ex vivo exposure to CPF produces tissue alterations and suggest that human placentais a potential target of CPF toxicity. In addition, it highlights the importance of using different models to assessthe effects of a toxic on human placenta.