Electroacupuncture enhances the mitophagy of granulosa cells in premature ovarian insufficiency model mice by inactivating the hippo-yes-associated protein/transcriptional co-activator with postsynaptic density protein, drosophila disc large tumor suppressor, and zonula occludens-1 protein binding motif pathway.

Abstract

Objective: To investigate the potential mechanism of electroacupuncture (EA) in alleviating premature ovarian insufficiency (POI) and to provide a theoretical basis for EA treatment of POI.

Methods: For this purpose, a POI mice model was developed by injecting 12 mg/kg busulfan and 120 mg/kg cyclophosphamide intraperitoneally to induce POI. It was then proceeded by EA intervention at Guanyuan (CV4) acupoint on the second day following modeling. Similarly, apoptosis in ovarian granulosa cells was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling staining, while enzyme-linked immunosorbent assay was employed for measuring serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen (E₂), and anti-müllerian hormone (AMH) levels. Moreover, transmission electron microscopy (TEM) was employed for examining mitochondrial morphology, while autophagy and hippo-yes-associated protein/transcriptional co-activator with postsynaptic density protein, drosophila disc large tumor suppressor, and zonula occludens-1 protein binding motif (YAP/TAZ) pathway related protein levels in ovarian tissue were detected via Western blotting.

Results: Analysis of serum levels of various hormones indicated that serum FSH and LH were reduced in EA compared to the POI group, while E₂ and AMH levels were found to be elevated in EA compared to the POI group. The EA was found to inhibit apoptosis in granulosa cells in POI model mice, in addition to improved mito-chondrial damage and significantly improved mitophagy. Pathway analysis revealed that EA was involved in activating the hippo-YAP/TAZ pathway, followed by reversing EA effects on granulosa cell apoptosis and mitophagy with the use of verteporfin, an autophagy and YAP-T-cell factor/enhancer of split and activator of transcription domain family member interaction inhibitor.

Conclusions: EA at the Guanyuan (CV4) acupoint protected the granulosa cell by inhibiting cell apoptosis and promoting mitophagy, which was mediated by the Hippo-YAP/TAZ pathway.