Mesenchymal stem cells reverse ovarian dysfunction by inhibiting autophagy in polycystic ovary syndrome mice

Polycystic ovary syndrome (PCOS) is a chronic inflammatory disorder that affects the reproductive health of 6%-20% of women of reproductive age worldwide. However, PCOS is yet to be completely cured. As a biomaterial that regulates the conditions of the female reproductive system, many studies have demonstrated that mesenchymal stromal cells (MSCs) have significant therapeutic potential for restoring impaired ovarian function. The purpose of the study was to examine the therapeutic benefits of human umbilical cord mesenchymal stromal cells (Huc-MSCs) in mice with dehydroepiandrosterone (DHEA)-induced PCOS and to assess their effects on ovulation, sex hormones, and the estrous cycle.

Flow cytometry (FCM) was used to identify Huc-MSCs. The expression of the autophagy-related proteins LC3 II, Beclin1, and mammalian target of rapamycin (mTOR) was evaluated by Western blot (WB) and real-time quantitative polymerase chain reaction (RT-qPCR). Changes in the number of autophagosomes were assessed by transmission electron microscope (TEM). DHEA was subcutaneously injected into female C57BL/6J mice to develop a PCOS model. The morphological changes in the ovaries and the number of oocytes at various stages of development in PCOS mice were observed using hematoxylin and eosin (H&E) staining. The levels of sex hormones were measured using enzyme-linked immunosorbent assay (ELISA), and the estrous cycle of PCOS mice was monitored using vaginal smears.

The PCOS patient group exhibited significantly higher levels of ATG5 and Parkin than the control group and a significant increase in the number of autophagosomes in the GCs of PCOS patients compared with those of non-PCOS women. Huc-MSCs are capable of repairing the impaired estrous cycle in PCOS mice and decreasing the level of testosterone (T) and the ratio of luteinizing hormone (LH)/ follicle-stimulating hormone (FSH) (LH/FSH ratio). Huc-MSCs are also able to repair ovulatory functions and facilitate oocytes maturation in PCOS mice. Autophagy suppression can improve oocytes viability in mice. Huc-MSCs also can inhibit granulosa cell autophagy, promote oocytes development, maintain homeostatic hormone levels, and restore the estrous cycle in PCOS mice. Huc-MSCs have the potential to treat ovarian dysfunction in PCOS mice by inhibiting autophagy pathway. In KGN cells and in DHEA-induced PCOS mice, mTOR expression was significantly downregulated. Huc-MSCs treatment markedly upregulated mTOR levels.

Our results suggest that Huc-MSCs improve ovarian dysfunction in PCOS by inhibiting autophagy, providing experimental evidence for the clinical application of hUC-MSCs and offering a new therapeutic approach for the treatment of PCOS.