RESUMO
Aim To establish three kinds of DNA damage models of mouse testicular spermatogonia cell line GC-1 cells and analyze their similarities and differences. Methods GC-1 cells were treated with UVB irradiation, D-galactose(D-Gal) or bleomycin (BLM), respectively. Then the expression and localization of 'Y-H2AX were detected by Western blot and immunofluorescence, the expression and localization of 8-OHdG were measured by immunofluorescence, and the expression levels of p-p53 and p21 were measured by Western blot. Results The expression of -y-H2AX in GC-1 cell reached to the peak 4 h after UVB irradiation and 6 h after D-Gal stimulation, whereas -y-H2AX expression gradually increased after BLM stimulation, and the higher the concentration of BLM,the shorter the time to reach the peak. The results of immunofluorescence showed that 8-OHdG expression was observed in the nucleus and cytoplasm of GC-1 cells after UVB irradiation and BLM stimulation, and the longer the culture time, the more the expression in the nucleus. In contrast, the expression of 8-OHdG was observed in the cytoplasm and reached the peak at 6 h in the D-Gal stimulated GC-1 cells. After UVB irradiation, the protein expression levels of p-p53 gradually increased, while p21 protein expression appeared later than that of p-p53; in the D-Gal stimulated GC-1 cells, the protein expression levels of p-p53 reached the peak at 6 h, and p21 protein expression reached the peak at 12 h; after low concentration BLM stimulation, the protein expression levels of p-p53 and p21 continuously increased, and after high concentration BLM stimulation, the protein expression levels of p-p53 and p21 reached its peak at 2 h, then decreased at 4 h. Conclusions Three kinds of DNA damage models of GC-1 cells are successfully established, and the DNA damage in GC-1 cells treated with D-Gal is mild, while the DNA damage in GC-1 cells treated by UVB irradiation and BLM stimulation is more severe.
RESUMO
To study the protective effects of Wuzi Yanzong recipe on DNA oxidative damage of testis germ cells in natural ageing rats based on Nrf2/HO-1 signaling pathway and base excision repair (BER). In the study, 16-month-old SPF grade male SD rats were randomly divided into three groups, namely ageing model group, and low and high-dose Wuzi Yanzong recipe groups (WZ, 1, 4 g·kg⁻¹). In addition, 2-month-old SD rats were used as adult control group (10 rats in each group). The ageing model group and the adult control group were fed with normal diet for 4 months. WZ groups were given medicated feed for 4 months. After fasting for 12 hours, the rats were put to death. Then, the testes were immediately removed. The vitality of superoxide dismutase (SOD) and malondialdehyde (MDA) content in testis were detected by xanthine oxidase method and thiobarbituric acid (TBA) method. The levels of Nrf2 and 8-OHdG were detected by immunofluorescence. The protein expression levels of Nrf2, HO-1, NQO1, APE1, OGG1 and XRCC1 were detected by Western blot. Compared with the ageing model group, WZ significantly increased the SOD vitality and decreased MDA content of testis. In addition, immunofluorescence results showed that WZ significantly attenuated testicular DNA oxidative damage and improved antioxidant capacity. Such changes were accompanied by the down-regulation of DNA oxidative damage response protein 8-OHdG levels and the up-regulation of Nrf2 levels. Moreover, Western blot results showed that WZ significantly increased the protein expression levels of Nrf2, HO-1 and NQO1 of the testis germ cells, when compared with ageing model group. In parallel, the protein expression levels of APE1, OGG1 and XRCC1 were significantly decreased. In conclusion, WZ improves ageing-related DNA oxidative damage via Nrf2/HO-1 and BER pathways.
RESUMO
To study the protective effects of Wuzi Yanzong recipe on testis germ cell apoptosis in natural ageing rats through endoplasmic reticulum stress (ERS), 16-month-old male SPF grade SD rats were randomly divided into three groups: ageing model group, and low and high-dose Wuzi Yanzong recipe groups (WZ, 1 and 4 g·kg⁻¹), with 10 rats in each group. In addition, 2-month-old SD male rats were used as adult control group. The ageing model group and the adult control group were fed with normal diet for 4 months. WZ groups were given the medicated feed for 4 months. After fasting for 12 hours, the rats were put to death. Then, the testes were immediately collected. The change of testicular tissue morphology was observed by HE staining. The expression levels of ER stress-related proteins GRP78, p-PERK, p-eif2, ATF4, p-IRE1, XBP1, ATF6 and apoptosis-related proteins CHOP, caspase12 and p-JNK in testes were detected by Western blot. Compared with the ageing model group, Wuzi Yanzong recipe alleviated the morphological changes of testicular tissue. Western blot results showed that Wuzi Yanzong recipe significantly increased the expression levels of endoplasmic reticulum stress-related proteins GRP78, p-PERK, p-eif2, ATF4, p-IRE1, XBP1, ATF6 and significantly decreased the expression levels of endoplasmic reticulum-induced apoptosis-related proteins CHOP, caspase 12 and p-JNK. In conclusion, Wuzi Yanzong recipe can alleviate the ageing-related apoptosis of testicular germ cells in natural ageing rats by regulating endoplasmic reticulum stress.