Cai Jia-Xing, Li Zhen, Dai Juan, Wang Xue-Lin, Zhang Hao, Cheng Jin-Xin
Key Laboratory of Occupational Hazards Identification and Control, School of Medicine, Wuhan University of Science and Technology, Wuhan, Hubei 430065, China.
Department of Chronic Diseases, Wuhan Center for Disease Control and Prevention, Wuhan, Hubei 430015, China.
Zhonghua Nan Ke Xue. 2022 Mar;28(3):195-202.
To study the impacts of exposure of F0 generation rats to 4-nonylphenol (4-NP) and bisphenal A (BPA) on the autophagy of testicular cells and key gene expressions of the Akt/mTOR pathway in the F1 generation offspring rats.
Using a 2×2 factorial design, F0 female and male rats were randomly assigned to receive intragastrically sigma vegetable oil (the control), BPA at 0.5 mg/kg, 4-NP at 5 mg/kg, and BPA+4-NP both at 0.5 mg/kg, respectively, qd alt for 30 days. Then the rats in each group were mated at a ratio of 1∶3. After pregnancy, the female rats continued the above intragastrical administration till delivery. The F1 generation male offspring rats were killed at 60 postnatal days, and their testes harvested for sperm count, observation of the morphological and autophagic changes of the testis, and determination of the relative mRNA expression levels of Akt, mTOR, 4EBP1 and p70S6K and protein expression levels of LC3-I and LC3-II.
The sperm count of the F1 generation male offspring rats was markedly decreased in the BPA and BPA+4-NP groups compared with that in the control (P < 0.05) but no significant interactive effect was observed between BPA and 4-NP (P > 0.05). The ratio of LC3-II / LC3-I was remarkably increased in the 4-NP, BPA and BPA+4-NP groups in comparison with that in the control (P < 0.05), and a significant interactive effect was shown between BPA and 4-NP (P < 0.05). The cells in the seminiferous tubules of the rats in the 4-NP, BPA and BPA+4-NP groups were loosely arranged, with a decreased count of sperm and increased number of autophagic vacuoles. Significant down-regulation was observed in the relative mRNA expression of p70S6K in the 4-NP group, as well as in that of mTOR in the BPA group and Akt in the BPA+4-NP group (all P < 0.05). A remarkably up-regulated expression of 4EBP1 mRNA was found in all the three intervention groups (P < 0.05), with a significant interactive effect between BPA and 4-NP on the expressions of Akt and 4EBP1 mRNA (P < 0.05).
Long-term exposure to low-concentration BPA and 4-NP impairs the testicular function of the F1 generation male offspring rats, which is closely related to the autophagy of testicular cells and changes of the Akt/mTOR pathway.
研究F0代大鼠暴露于4-壬基酚（4-NP）和双酚A（BPA）对F1代子代大鼠睾丸细胞自噬及Akt/mTOR信号通路关键基因表达的影响。
采用2×2析因设计，将F0代雌雄大鼠随机分为4组，分别经口灌胃给予西格玛植物油（对照组）、0.5 mg/kg BPA、5 mg/kg 4-NP、0.5 mg/kg BPA + 5 mg/kg 4-NP，每日1次，连续30天。然后每组大鼠按1∶3比例交配。受孕后，雌性大鼠继续上述灌胃给药直至分娩。F1代雄性子代大鼠出生后60天处死，取睾丸进行精子计数、睾丸形态及自噬变化观察，并检测Akt、mTOR、4EBP1和p70S6K的相对mRNA表达水平以及LC3-I和LC3-II的蛋白表达水平。
与对照组相比，BPA组和BPA + 4-NP组F1代雄性子代大鼠精子计数显著降低（P < 0.05），但BPA与4-NP之间未观察到显著的交互作用（P > 0.05）。与对照组相比，4-NP组、BPA组和BPA + 4-NP组LC3-II / LC3-I比值显著升高（P < 0.05），且BPA与4-NP之间存在显著的交互作用（P < 0.05）。4-NP组、BPA组和BPA + 4-NP组大鼠生精小管细胞排列疏松，精子数量减少，自噬空泡数量增加。4-NP组p70S6K相对mRNA表达显著下调，BPA组mTOR以及BPA + 4-NP组Akt相对mRNA表达均显著下调（均P < 0.05）。三个干预组4EBP1 mRNA表达均显著上调（P < 0.05），且BPA与4-NP对Akt和4EBP1 mRNA表达存在显著的交互作用（P < 0.05）。
长期低浓度暴露于BPA和4-NP会损害F1代雄性子代大鼠睾丸功能，这与睾丸细胞自噬及Akt/mTOR信号通路变化密切相关。
