Hazards of bisphenol A -- blocks RNA splicing leading to abnormal testicular development in offspring male mice.

This study was conducted to investigate the effects of maternal exposure to BPA on testicular development in offspring males. Pregnant Kunming mice were randomly divided into 7 groups with 20 mice in each group. Group A was the control group and the mice were given distilled water orally. Mice in groups B, C, D, E, F, G received BPA orally at a dose of 0.05 mg/kg/d, 0.5 mg/kg/d, 5 mg/kg/d, 10 mg/kg/d, 20 mg/kg/d, 50 mg/kg/d, respectively. F0 mice were exposed to BPA for 40 days from gestation day 0 to lactation day 21. F1 male mice were sacrificed at weaning (postnatal day 21). Histological observations revealed architectural damages in testis in BPA exposed groups. The testicular organ index increased significantly when the BPA oral exposure dose was above 20 mg/kg/d (P < 0.05). BPA contents in serum of F1 male mice increased significantly when BPA was above 5 mg/kg/d (P < 0.05), while the contents significant increased in maternal serum when BPA was higher than 0.5 mg/kg/d. The damage of cell nuclear DNA of testis was significantly aggravated when BPA was above 5 mg/kg/d. The expression of AR in the testis was significantly increased when BPA was above 20 mg/kg/d (P < 0.05). Transcriptome sequencing showed that the Snrnp 40 which encoding U5 snRNA subunit was significantly up-regulated in spliceosome pathway, and the Hnrnpu which encoding splicing universal protein component was significantly down-regulated. The blockage of spliceosome might be one of the reasons why BPA affects testicular development.