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Spermidine, a natural polyamine, has been proven antioxidant function, but its pathway and mechanism of action remain unclear. Based on the oxidative stress model by 3-nitropropionic acid (3-NPA), the study explored the pathways by spermidine to rescue oxidative stress via autophagic process in goose granulosa cells by RNA-seq and RNA interference. In transcriptional regulation, in addition to KEGG pathways related to cell proliferation and differentiation, lots of KEGG pathways associated with inflammation, metabolism, and signaling were also significantly enriched in 3-NPA vs. 3-NPA + spermidine treatments. Six key genes (JUN , CD44 , KITLG , RND2 , BMP4 and KALRN) involved in spermidine-mediated anti-oxidative stress were screened. Furthermore, the experimental results showed that spermidine (80 μmol/L) significantly increased autophagic gene expression in goose granulosa cells, while EP300 -siRNA or MAP1S -siRNA also significantly increased autophagic process. The autophagic gene expressions were no difference between EP300 -siRNA and EP300 -siRNA + spermidine treatments, although spermidine significantly increased autophagic process of granulosa cells compared to MAP1S -siRNA alone. In addition, inhibition of mTOR pathway significantly increased autophagic gene expression, which was further enhanced by spermidine in combined with mTOR inhibitor. These results suggest that spermidine can alleviate oxidative stress by inducing autophagy regulated by EP300, MAP1S and mTOR as well as regulating other independent gene expressions in goose granulosa cells. • Spermidine improves oxidative stress in goose GCs by regulating autophagy and other independent gene expressions. • Transcriptomic techniques confirmed the target genes related to spermidine anti-oxidative stress by spermidine. • The autophagy pathway involved in anti-oxidative stress by spermidine was validated by gene interference analyses. [ABSTRACT FROM AUTHOR]

To investigate the relationship between polyamine metabolism and reproductive hormones in ovarian follicles of Sichuan white geese, follicle polyamine content and reproductive hormone levels and gene expressions related to polyamine metabolism, steroidogenesis and steroid hormone receptors were detected by HPLC, ELISA and RT-qPCR. The results showed that the overall trend of spermidine and spermine levels increased first and then decreased as increasing follicle size, with the highest level in F3 and F5 follicles (P < 0.05). Putrescine and 17β-estradiol (E2) levels in hierarchical follicles were significantly lower than those in prehierarchical follicles (P < 0.05). Progesterone (P4) first increased and then decreased, with the highest level in the F5 follicle (P < 0.05). The expression levels of estrogen receptor 1 (ER1) showed an overall increase as increasing follicle size (except in F3 follicles), while estrogen receptor 2 (ER2) in hierarchical follicles was significantly lower than that in the prehierarchical follicles (P < 0.05). In addition, the overall expression level of progesterone receptor (PR) decreased, with no significant differences among F1, F2 and F3 follicles (P > 0.05). Yolk putrescine contents were positively correlated with yolk E2 concentrations and PR expression levels (P < 0.05), A significant positive correlation of spermidine levels with yolk P4 concentrations and PR expressions was also observed, as well as the spermine levels with yolk P4 concentrations (P < 0.05). In summary, polyamines were involved in the regulation of follicular development in geese, and this regulation played a role in affecting steroidogenesis and the expression of genes related to hormone receptors. • Polyamine affects the steroidogenesis. • Polyamine contents show a specific change during goose follicular development. • Polyamine affects the expression of genes related to reproductive hormones. [ABSTRACT FROM AUTHOR]

Spermidine have been reported a role in antioxidative, antiaging, and antiinflammatory. Oxidative stress causes granulosa cell (GC) apoptosis, follicular atresia, and impairs poultry reproductive functions. Studies have found that autophagy is the protective mechanism against antioxidant stress and apoptosis in cells. However, the relationship between spermidine-induced autophagy, oxidative stress, and apoptosis in goose GCs remains unclear. In this study, we investigated the autophagy mechanism to mediate spermidine effects on the alleviation of oxidative stress and apoptosis in goose GCs. Follicular GCs were treated with spermidine combination with 3-Nitropropanoic acid (3-NPA), rapamycin (RAPA), and chloroquine (CQ) or with hydrogen peroxide, RAPA, and CQ. Spermidine upregulated the ratio of LC3-II/I, inhibited the accumulation of p62 protein, and induced autophagy. 3-NPA treatment significantly increased ROS production, MDA content, SOD activity, cleaved CASPASE-3 protein expression, and decreased BCL-2 protein expression in follicular GCs. Spermidine inhibited oxidative stress and apoptosis induced by 3-NPA. In addition, hydrogen peroxide-induced oxidative stress was inhibited by spermidine. However, the inhibitory effect of spermidine was eliminated under chloroquine. Our results demonstrated that spermidine relieved oxidative stress and apoptosis of GCs by inducing autophagy, indicating that spermidine has a great potential to maintain proteostasis and sustain granulosa cell viability in geese. [ABSTRACT FROM AUTHOR]

Oxidative stress is the major culprits responsible for ovarian dysfunction by damaging granulosa cells (GCs). Ferritin heavy chain (FHC) may participate in the regulation of ovarian function by mediating GCs apoptosis. However, the specific regulatory function of FHC in follicular GCs remains unclear. Here, 3-nitropropionic acid (3-NPA) was utilized to establish an oxidative stress model of follicular GCs of Sichuan white geese. To explore the regulatory effects of FHC on oxidative stress and apoptosis of primary GCs in geese by interfering or overexpressing FHC gene. After transfection of siRNA- FHC to GCs for 60 h, the expressions of FHC gene and protein decreased significantly (P < 0.05). After FHC overexpression for 72 h, the expressions of FHC mRNA and protein upregulated considerably (P < 0.05). The activity of GCs was impaired after interfering with FHC and 3-NPA coincubated (P < 0.05). When overexpression of FHC combined with 3-NPA treatment, the activity of GCs was remarkably enhanced (P < 0.05). After interference FHC and 3-NPA treatment, NF-κB and NRF2 gene expression decreased (P < 0.05), the intracellular reactive oxygen species (ROS) level increased greatly (P < 0.05), BCL-2 expression reduced, BAX/BCL-2 ratio intensified (P < 0.05), the mitochondrial membrane potential decreased notably (P < 0.05), and the apoptosis rate of GCs aggravated (P < 0.05). While overexpression of FHC combined with 3-NPA treatment could promote BCL-2 protein expression and reduce BAX/BCL-2 ratio, indicating that FHC regulated the mitochondrial membrane potential and apoptosis of GCs by mediating the expression of BCL-2. Taken together, our research manifested that FHC alleviated the inhibitory effect of 3-NPA on the activity of GCs. FHC knockdown could suppress the expression of NRF2 and NF-κB genes, reduce BCL-2 expression and augment BAX/BCL-2 ratio, contributing to the accumulation of ROS and jeopardizing mitochondrial membrane potential, as well as exacerbating GCs apoptosis. [ABSTRACT FROM AUTHOR]

After Wenchuan Ms8.O earthquake, the surface fractures have been investigated in Beichuan City and Yingxiu Town. It was found that the Beichuan-Yingxiu earthquake fracture zone trends northeastward, dipping to northwest. The earthquake fracture zone is mainly characterized by thrust faulting with small amounts of strike-slip movement, and demonstrating various complexities for different areas. The phenomena related to dextral strike-slip displacement are found in Beichuan City and those related to left-lateral strike-slip movement in Yingxiu Town. The compressive shortening of the two surface fracture zones in Beichuan City is 2.8-3.9 m and the left-lateral strike-slip displacement of the surface fractures in Yingxiu Town is 0.52 m. [ABSTRACT FROM AUTHOR]