Diuron-induced fetal Leydig cell dysfunction in in vitro organ cultured fetal testes

Diuron is a phenylurea herbicide widely used in the agricultural industry. In recent years, the risk of infertility and developmental defects has increased due to exposure to environmental pollutants. In this study, we investigated the toxicity of diuron in fetal mouse testes using three-dimensional organ cultures. Fetal testes derived from embryonic day (E) 14.5 were cultured with 200 µM diuron for 5 days. The results revealed that diuron did not impair fetal germ cell proliferation or the expression levels of germ cell markers such as Ddx4, Dazl, Oct 4, Nanog, Plzf, and TRA 98. Similarly, the gene or protein expression of the Sertoli cell markers Sox9 and Wt1 in diuron-exposed fetal testes did not change after 5 days of culture. In contrast, diuron increased fetal Leydig cell markers (FLC), Cyp11a1, Cyp17a1, Thbs2, and Pdgf α, and decreased adult Leydig cell (ALC) markers, Sult1e1, Hsd173, Ptgds, and Vcam1. However, 3-βHSD, an FLC and ALC marker, was consistently maintained upon exposure to diuron in fetal testes compared to non-treated groups. In conclusion, our study demonstrates that diuron negatively impacts Fetal Leydig cell development, although it does not affect germ and Sertoli cells.