Endometrial stem cell-derived exosomes repair cisplatin-induced premature ovarian failure via Hippo/YAP pathway

Background: Stem cells have been documented as a new therapeutic method for ovarian injuries such as premature ovarian failure (POF). However, effects of exosomes (Exos) derived from human endometrial stem cells (EnSCs) on diminished ovarian failure remain to be carefully elucidated. Our study aims to investigate the mechanisms of EnSC-Exos in the recovery of the cisplatin-induced granulosa cell injury model in vitro or POF mouses model in vivo and whether the Hippo signal pathway is involved in the regulation. Methods: : Exosomes derived from human EnSCs were isolated by ultracentrifugation and identified by electron microscopy and western blot (WB) analysis, stained by PKH26, respectively. The mechanism involving suppression of Hippo signaling pathway and activation of Yes-associated protein (YAP) was investigated for evaluating EnSC-Exos therapeutic effects in the cisplatin-induced granulosa cell injury model in vitro using flow cytometry, WB, qRT-PCR, immunofluorescence and EdU staining. Hematoxylin-eosin staining, ELISA and immunohistochemistry analysis were used for evaluating EnSC-Exos therapeutic effects in POF mouses model. Results: : In this study, we established successful construction of the cisplatin-induced granulosa cell injury model and evaluated Hippo signaling pathway activation in cisplatin-damaged granulosa cells (GCs). Furthermore, laser scanning confocal microscope and immunofluorescence demonstrated that EnSC-Exos can be transferred to cisplatin-damaged GCs to decrease apoptosis. In addition, the enhanced expression of YAP at the protein level as well as YAP/TEAD target genes, such as CTGF, ANKRD1 and the increase of YAP into the nucleus in immunofluorescence staining after the addition of EnSC-Exos to cisplatin-damaged GCs confirmed the suppression of Hippo signaling. While in vivo , EnSC-Exos successfully remedied POF in a mouse model. Conclusions: : Collectively, our findings suggest that human EnSC-Exos is effective in recovery of ovarian function by chemotherapy-induced POF via activating YAP and inhibiting the Hippo signaling pathway. These findings provide new insights for further understanding of EnSC-Exos in the recovery of ovary function.