[4-nonylphenol combined with bisphenol A induces testicular autophagy and spermatogenic impairment by inhibiting the Akt/mTOR pathway in F1 male offspring rats].

OBJECTIVE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

[Impact of Cadmium on the expressions of piRNAs in the rat testis].

OBJECTIVE: To study the impact of cadmium (Cd) on the expressions of PIWI-interacting RNAs (piRNA) in the rat testis and its possible action mechanism. METHODS: Twelve 6-week-old SD rats were randomly divided into a Cd-exposure and a control group, the former gavaged with CdCl2 at 3 mg/kg/d and the latter with normal saline, all for 28 successive days. Then the testicular tissues were collected from the rats, sperm concentration and motility were obtained by computer-assisted sperm analysis (CASA), and piRNA sequencing was performed using the gene chip, followed by bioinformatics analysis of differentially expressed piRNAs. RESULTS: Compared with the controls, the rats in the Cd-exposure group showed significantly decreased sperm concentration and motility (P < 0.05). The expressions of 272 piRNAs were up-regulated and 402 down-regulated after 28 days of Cd exposure, and 4 of the up-regulated piRNAs were consistent with the results of gene chip verification. Bioinformatics analysis showed that the 4 up-regulated piRNA target genes were involved in 50 biological processes, such as negative regulation of apoptosis, positive regulation of gene expression and positive regulation of GTPase activity, and mainly concentrated in 13 signaling pathways including transcription dysregulation, calcium and mitogen-activated protein kinase signaling pathways in cancer. Among them, PIRNA-DQ765261 had a binding site with Bcl-2. CONCLUSION: Cadmium can induce changes in the expressions piRNAs in the rat testicular tissue, and some piRNAs may be involved in the autophagy and apoptosis of sperm. Bcl-2 may be the target of PIRNA-DQ765261.

[An improved method and its application for agricultural drought monitoring based on remote sensing].

From the viewpoint of land surface evapotranspiration, and by using the semi-empirical evapotranspiration model based on the Priestley-Taylor equation and the land surface temperature-vegetation index (LST-VI) triangle algorithm, the current monitoring technology of agricultural drought based on remote sensing was improved, and a simplified Evapotranspiration Stress Index (SESI) was derived. With the application of the MODIS land products from March to November in 2008 and 2009, the triangle algorithm modeling with three different schemes was constructed to calculate the SESI to monitor the agricultural drought in the plain areas of Beijing, Tianjin, and Hebei, in comparison with the Temperature Vegetation Dryness Index (TVDI). The results showed that SESI could effectively simplify the remote sensing drought monitoring method, and there was a good agreement between SESI and surface soil (10 and 20 cm depth) moisture content. Moreover, the performance of SESI was better in spring and autumn than in summer, and the SESI during different periods was more comparable than TVDI. It was feasible to apply the SESI to the continuous monitoring of a large area of agricultural drought.