OBJECTIVE

Premature ovarian insufficiency (POI) is a disease with medical, psychological and reproductive implications, but its common therapies have limited efficacy and a likelihood of complications. This study delves into the therapeutic role of human umbilical cord mesenchymal stem cell-derived extracellular vesicles (hUC-MSCs-EVs) in POI mice through the insulin-like growth factor 1 (IGF-1)/nuclear factor E2 related factor 2 (Nrf2)/heme oxygenase-1 (HO-1)/autophagy pathway.

METHODS

hUC-MSCs were transfected with lentiviral short hairpin RNA of IGF-1 before EV extraction. Cyclophosphamide (CTX)-induced POI mouse models were administrated with hUC-MSCs-EVs. Mouse ovarian granulosa cells (GCs) were induced with CTX, then treated with hUC-MSCs-EVs and ML385. Ovarian histopathological changes were observed, changes in follicle number at all levels were counted and serum sex hormones were evaluated, as well as LC3II/I and Beclin-1 expression. GCs were subject to detection of proliferation, deaths, oxidative stress, and Nrf2 nuclear translocation.

RESULTS

After CTX exposure, mice showed thinner GCs layer in the ovary, reduced number of GCs and follicles at all levels, disturbed serum sex hormones, enhanced oxidative stress and autophagy, and downregulated ovarian IGF-1; whereas, hUC-MSCs-EVs upregulated IGF-1 to improve the ovarian function. hUC-MSCs-EVs carrying IGF-1 activated Nrf2/HO-1 signaling to inhibit CTX-induced excessive autophagy of GCs, but this ameliorative effect was partially weakened by inhibiting Nrf2/HO-1 signaling. hUC-MSCs-EVs inhibited excessive autophagy of GCs and improved ovarian function of CTX-induced mice through IGF-1/Nrf2/HO-1 pathway.

CONCLUSION

hUC-MSCs-EVs activate the Nrf2/HO-1 signaling by carrying IGF-1, which in turn inhibits excessive autophagy and damage of GCs, thus improving ovarian function in POI mice.