Effect of acupuncture at "Zhibian" (BL 54) through "Shuidao" (ST 28) on PI3K/AKT/FOXO3a pathway in mice with poor ovarian response

Abstract

To observe the protective effect of acupuncture at "Zhibian" (BL 54) through "Shuidao (ST 28)" based on the PI3K/AKT/FOXO3a pathway in mice with poor ovarian response (POR), and to explore the possible mechanism of acupuncture in inhibiting ovarian granulosa cells apoptosis in POR. A total of 45 mice with regular estrous cycles were randomly divided into a blank group, a model group and an acupuncture group, with 15 mice in each group. Mice in the model group and the acupuncture group were given triptolide suspension (50 mg•kg-1•d-1) by gavage for 2 weeks to establish POR model. After successful modeling, mice in the acupuncture group were given acupuncture at "Zhibian" (BL 54) through "Shuidao" (ST 28) for 2 weeks, once a day, 20 min each time. Ovulation induction was started the day after the intervention ended, and samples were taken from each group after ovulation induction. Vaginal smears were used to observe changes in the estrous cycle of mice. The number of oocytes retrieved, ovarian wet weight, final body weight, and ovarian index were measured. The levels of anti-Mullerian hormone (AMH), follicle-stimulating hormone (FSH), estradiol (E2), and luteinizing hormone (LH) in serum were detected by ELISA. The morphology of ovarian tissue was observed by HE staining. The apoptosis of ovarian granulosa cells was detected by TUNEL staining. The mRNA expression of PI3K, AKT, and FOXO3a in ovarian tissue was detected by real-time fluorescence quantitative PCR. The protein expression of Bcl-2 associated X protein (BAX), caspase-3, phosphorylated phosphatidylinositol 3-kinase (p-PI3K), and phosphorylated protein kinase B (p-AKT) in ovarian tissue was detected by Western blot. Compared with the blank group, the rate of estrous cycle disorder in the model group was increased (P<0.01); compared with the model group, the rate of estrous cycle disorder in the acupuncture group was decreased (P<0.01). Compared with the blank group, the number of oocytes retrieved, ovarian wet weight, ovarian index, and final body weight in the model group were decreased (P<0.01); compared with the model group, the number of oocytes retrieved, ovarian index, and ovarian wet weight were increased (P<0.01, P<0.05), and there was no significant difference in final body weight (P>0.05) in the acupuncture group. Compared with the blank group, the serum levels of FSH and LH were increased (P<0.01), and the serum levels of AMH and E2 were decreased (P<0.01) in the model group; compared with the model group, the serum levels of FSH and LH were decreased (P<0.01, P<0.05), and the serum levels of AMH and E2 were increased (P<0.01, P<0.05) in the acupuncture group. Compared with the blank group, the number of normal developing follicles in ovarian tissue in the model group was decreased and the morphology was poor, while the number of atretic follicles increased; compared with the model group, the number, morphology, and granulosa cell structure of follicles in the acupuncture group improved to varying degrees, and the number of atretic follicles decreased. Compared with the blank group, the apoptosis rate of ovarian granulosa cells in the model group was increased (P<0.01); compared with the model group, the apoptosis rate of ovarian granulosa cells in the acupuncture group was decreased (P<0.01). Compared with the blank group, the FOXO3a mRNA expression and caspase-3 and BAX protein expression in ovarian tissue in the model group were increased (P<0.01), and the mRNA expression of PI3K and AKT and the protein expression of p-PI3K, p-AKT, and p-FOXO3a in ovarian tissue were decreased (P<0.01); compared with the model group, the mRNA expression of FOXO3a and protein expression of caspase-3 and BAX in ovarian tissue in the acupuncture group were decreased (P<0.05, P<0.01), and the mRNA expression of PI3K and AKT and the protein expression of p-PI3K, p-AKT, and p-FOXO3a in ovarian tissue were increased (P<0.01, P<0.05). Acupuncture at "Zhibian" (BL 54) through "Shuidao" (ST 28) could inhibit ovarian cell apoptosis, and improve ovarian function in POR mice, and its mechanism may be related to the regulation of key factors in the PI3K/AKT/FOXO3a pathway.