Establishment of a germ-somatic cell coculture model for toxicity assessment of environmental endocrine disrupters

The objective of this study was to evaluate the effect of environmental endocrine disrupting chemicals by a germ--somatic cell coculture model in vitro. Testicular cells of 18-day-old chicken embryos were dispersed and cultured in different media. Results showed that somatic cells formed a monolayer to which germ cells adhered in the medium supplemented with insulin (Ins), transferrin (Tf), and selenite (Se) (ITS medium). However, the medium without ITS or single subtraction of Ins, Tf, or Se could not maintain cell survival in culture because many germ cells manifested apoptosis. Three known endocrine disrupters were selected to test the feasibility of this model. Aroclor 1254 (A1254, 10 microg/mL) induced condensed nuclei and vacuolated cytoplasm in germ cells, which was further confirmed by a cell proliferation assay. However, after culture for 48 h, the number of germ cells displayed a significant augment stimulated by A1254 (0.1-10 microg/mL) (P < 0.05). Similarly, 2,4-dichlorophenoxyacetic acid and busulfan displayed notable toxic effects on germ cells, and germ cell number and cell viability were significantly decreased in a dose-dependent manner (P < 0.05). The above results indicate that the chicken testicular germ-somatic cell coculture model is a simple, rapid, and veracious in vitro tool for evaluating the effect of environmental endocrine disrupters on functional basis of the cultured cells.