Amniotic fluid-derived exosomes attenuated fibrotic changes in POI rats through modulation of the TGF-β/Smads signaling pathway

In the current study, we investigated the regenerative effects of amniotic fluid exosomes (AF-Exos) in a rat model for premature ovarian insufficiency (POI). POI is a condition characterized by a decrease in ovarian function that can lead to infertility. We induced POI by administering cyclophosphamide (CTX) for 15 consecutive days, and then transplanted AF-Exos directly into both ovarian tissues. Four weeks later, we measured the serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2), and performed histopathological evaluations using H & E and Masson’s trichrome staining. We also monitored the expression of genes related to the TGF-β signaling pathway using real-time PCR and examined the fertility rate of POI rats after AF-Exos therapy. Histological analysis showed an increase in atretic follicles and a decrease in healthy follicle count after POI induction. Four weeks post-AF-Exos intervention, the healthy follicle count increased (p < 0.01) while the atretic follicle count decreased (p < 0.001). In parallel, the deposition of collagen fibers also decreased following AF-Exos transplantation. The concentrations of FSH and LH hormones in sera remained unchanged after injection of AF-Exos, while E2 levels increased (p < 0.05). The expression of Smad-4 (p < 0.01) and Smad-6 (p < 0.05) was upregulated in POI rats that received AF-Exos, while Smad-2, TGF-β1, TNF-α, and IL-10 remained statistically unchanged. Our records showed a notable increase in litter number after AF-Exos compared to the non-treated POI rats. These results suggest that AF-Exos transplantation has the potential to restore ovarian function through the TGF-β/Smads signaling pathway in POI rats.