[Study on the protective effect of acupuncture on poor ovarian response in mice].

Objectives: To observe the protective effect of acupuncture on ovarian function and its impact on key molecules (Yes associated protein ［YAP］ and transcriptional coactivator with PDZ binding motif ［TAZ］) in the Hippo signaling pathway in poor ovarian response (POR) mice, in order to explore its mechanisms underlying improvement of POR by inhibiting ovarian cell apoptosis.

Methods: The mice with regular motility cycle after screening were randomly divided into normal control, model and acupuncture groups, with 12 mice in each group. The POR model was established by gavage of tripterygium wilfordii polyglycoside suspension (50 mg · kg·d) for 2 weeks, and the mice of the normal control group was received an equal volume of 0.9% sodium chloride solution by gavage. The mice in the acupuncture group received manual acupuncture stimulation of bilateral "Taichong" (LR3) and "Sanyinjiao" (SP6), and "Zhongji" (CV3) and "Guanyuan" (CV4), with the filiform needles retained for 20 min, once daily for successive 10 days. The estrous cycle was determined by using vaginal exfoliated cell smear, and the body mass was detected weekly. The levels of serum anti Mullerian hormone (AMH), follicle stimulating hormone (FSH), estradiol (E2) and luteinizing hormone (LH) were measured using enzyme-linked immunosorbent assay (ELISA). Histopathological changes of the ovarian tissue were observed after H.E. staining, and the apoptosis of ovarian granulosa cells was measured using terminal deoxynucleotidyl transferase (TdT) dUTP Nick-End Labeling (TUNEL) assay. The expression levels of YAP, TAZ, B-cell lymphoma-2 (Bcl-2), Bcl-2 associated X (Bax), cysteine aspartic acid specific protease-3 (Caspase-3) mRNAs and proteins were detected using real-time PCR and Western blot, respectively.

Results: Compared with the normal control group, the model group had an increase in the rate of estrous cycle disorder, estrous cycle, serum FSH and LH content, and apoptosis of ovarian granulosa cells, and expression levels of Bax and Caspase-3 mRNAs and p-YAP, Bax and Caspase-3 proteins (<0.01), and a decrease in the body mass, number of retrieved oocytes, ovarian wet weight and ovarian index, serum AMH and E2 contents, and the expression levels of YAP, TAZ, Bcl-2 mRNAs and proteins (<0.01). After acupuncture intervention, modeling induced increase and decrease of indexes mentioned above were completely reversed (<0.05, <0.01). H.E. staining showed deformed ovarian structure, reduced number of normal developing follicles and increased number of atretic follicles, disordered arrangement of the granulosa cells with fewer hierarchy in the model group, which was improved in the acupuncture group, such as increase in the number and improvement in the shape of normal ovarian follicles and reduction of the atretic follicles.

Conclusions: Acupuncture intervention can inhibit the apoptosis of ovarian granulosa cells and improve the ovarian function of POR mice, which may be related to its effects in up-regulating the expressions of YAP, TAZ (key molecules of Hippo signaling pathway).