Cytoskeletons of Two Reproductive Germ Cell Lines Response Differently to Titanium Dioxide Nanoparticles Mediating Vary Reproductive Toxicity

Titanium dioxide nanoparticles (TiO2 NPs) have been widely used for many years. Their toxic effects on the male reproductive system had been reported, but the underlying mechanisms were still not clear. Here we utilized two germ cell lines (GC-2 and TM4) to explore the possible toxic effects of TiO2 NPs on male reproductive system. Our results showed that TiO2 NPs did not affect cell viability but induced cell apoptosis of both GC-2 and TM4 cells up to 100 mu g/ml. Microtubule networks and microtubule dynamics of GC-2 but not TM4 cells were changed. The microfilaments arrangement of TM4 cells altered after treated with TiO2 NPs, and the phagocytosis activity of TM4 cells decreased significantly. Although the microfilament network of GC-2 cells seemed normal, the migration ability of GC-2 cells was significantly impaired. Totally TiO2 NPs is toxic to GC-2 cells by inducing cell apoptosis, disturbing microtubule arrangement and microtubule dynamic, and impairing cell migration ability. In addition, they altered the microfilament network and reduced the phagocytic activity of TM4 cells. We firstly reported that cytoskeletons (microtubules and microfilaments) in different cells showed different responses to TiO2 NPs, which might mediate different toxic mechanisms.