Fertility protection: a novel approach using pretreatment with mesenchymal stem cell exosomes to prevent chemotherapy-induced ovarian damage in a mouse model.

Background: Primary ovarian insufficiency refers to the loss of ovarian function before the age of 40 years and leads to amenorrhea and infertility. Primary ovarian insufficiency has diverse causes, but a common cause is exposure to gonadotoxic chemotherapy used in cancer treatment. Because of the risk for developing primary ovarian insufficiency, patients who want to preserve their fertility may consider various procedures for fertility preservation. However, current fertility preservation options are highly invasive, carry substantial risks, and have uncertain success rates. Recent studies from our group and others reported that mesenchymal stem cells and mesenchymal stem cell-derived exosomes can restore ovarian function in preclinical models of primary ovarian insufficiency by restoring damaged cells and inhibiting apoptosis. Although the restorative effect of mesenchymal stem cell-derived exosomes has been well reported in previous studies, the potential of mesenchymal stem cell-derived exosomes in preventing ovarian damage has not been fully elucidated.

Objective: This study hypothesized that the antiapoptotic potential of mesenchymal stem cell-derived exosomes may protect ovarian tissue from chemotherapy-induced damage.

Study Design: In this study, we delivered mesenchymal stem cell-derived exosomes directly into the ovaries of mice before administration of chemotherapy. A total of 60 mice were divided into 3 groups (20 per group), which were labeled the control, chemotherapy, and fertility protection groups. Only the fertility protection group mice received exosomes, whereas the control and chemotherapy group mice received saline. After exosome injection, the chemotherapy and fertility protection groups of mice were subjected to chemotherapy to induce ovarian damage. After chemotherapy, we evaluated the protective effects of exosome treatment on ovarian function, such as estrous cyclicity, serum hormone levels, and the fertility rate, by comparing these outcomes between the chemotherapy and fertility protection groups. These outcomes were also compared with those of the control group for comparison with outcomes under healthy conditions.

Results: After intraovarian injection of exosomes before chemotherapy, the mice were able to maintain their estrous cycle (4- to 5-day cyclicity), serum anti-müllerian hormone level (66.06±26.40 ng/mL, not significantly different from that of the healthy controls), folliculogenesis (32.2±11.3 in the chemotherapy group vs 46.4±14.1 in the fertility protection group; P<.05), expression of the steroidogenic acute regulatory protein gene (a the steroidogenesis marker) (0.44±0.11-fold expression in the chemotherapy group and 0.88±0.31-fold expression in the fertility protection group; P<.05), and fertility (2 of 8 in the chemotherapy group and 5 of 8 in the fertility protection group), thereby showing prevention of chemotherapy-induced damage. We found that exosome treatment before chemotherapy can preserve ovarian function and protect fertility through the overexpression of ATP synthase-binding cassette transporters, such as ABCB1b (10.17±17.75-fold expression in the chemotherapy group and 44.14±33.25-fold expression in the fertility protection group; P<.05) and ABCC10 (3.25±0.59-fold expression in the chemotherapy group and 5.36±1.86-fold expression in the fertility protection group; P<.05).

Conclusion: In this study, we present a novel fertility protection method using mesenchymal stem cell-derived exosomes. We concluded that mesenchymal stem cell-derived exosomes are a promising and simple treatment option for fertility protection in reproductive-aged patients who are receiving gonadotoxic chemotherapy.