HD-sEVs in bovine follicular fluid regulate granulosa cell apoptosis and estradiol secretion through the autophagy pathway
- Theriogenology. 2023 Dec:212:91-103. doi: 10.1016/j.theriogenology.2023.09.005.
- 1. Chongqing Key Laboratory of Forage &Herbivore, College of Veterinary Medicine, Southwest University, Beibei, Chongqing, 400715, China; Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- 2. Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China.
- 3. Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi, 712100, China. Electronic address: [email protected].
Follicular fluid (FF) is rich in extracellular vesicles (EVs), which have regulatory effects on follicular growth and oocyte development. EVs can be divided into two subtypes, i.e. HD-sEVs and LD-sEVs. In this study, HD-sEVs were successfully isolated from bovine follicular fluid (BFF) by density gradient ultracentrifugation. By western blot, quantitative polymerase chain reaction (qPCR), flow cytometry, transmission electron microscopy (TEM) and enzyme-linked immunosorbent assay (ELISA), this study found HD-sEVs promoted Autophagy in bGCs by increasing the protein and mRNA expression of LC3II/LC3I ratio and Beclin1, and inhibiting the protein and mRNA expression of p62. HD-sEVs promoted Mitophagy in bGCs by increasing the protein and mRNA expression of VDAC1, CTSD, and HSP60. Flow cytometry showed that HD-sEVs inhibited bGCs Apoptosis rate. HD-sEVs promoted estradiol secretion by increasing steroidogenesis-associated proteins and mRNA, such as CYP19A, HSD3B in bGCs. HD-sEVs promoted autophagosome formation and mitochondrial structure swelling in bGCs, and decreased p-mTOR/mTOR ratio. The above phenomenon was reversed when wortmannin was added. Collectively, BFF HD-sEVs promote bGCs Autophagy and Mitophagy, inhibit bGCs Apoptosis and promote estradiol secretion through the Autophagy pathway-mTOR signaling pathway.