Modulation of PI3K/AKT/mTOR signaling pathway by combined stem cell and phytochemical treatment improves metabolic and reproductive outcomes in PCOS.

BACKGROUND: PCOS is characterized by ovulatory dysfunction and metabolic abnormalities, and growing evidence suggests that dysregulated autophagy in ovarian granulosa cells contributes to its pathogenesis. Mesenchymal stem cells (MSCs) and Medicine Lin (ML) therapy have been proven to improve these dysfunctions in PCOS patients, enhancing fertility and pregnancy outcomes, though their underlying mechanisms remain unclear. This study hypothesized that MSCs and ML function by regulating the autophagy-mediated PI3K/AKT/mTOR signaling pathway. METHODS: A PCOS mouse model was established through high-fat, high-sugar diet and letrozole induction. MSCs and ML treatment was administered for three weeks, followed by fertility testing. Ovarian morphological changes were examined using H&E and Masson staining, autophagosomes in granulosa cells were observed via transmission electron microscopy, serum hormone levels were measured by using ELISA kits, fetal umbilical blood flow was monitored with Doppler ultrasound, cell apoptosis and LC3II expression in ovarian and placental tissues were evaluated using TUNEL and immunofluorescence, and Western blot was used to analyze expressions of PI3K, AKT, FOXO1, mTOR, S6K1, Beclin1, P62, LC3II / LC3I, and ROS. RESULTS: Combined MSCs and ML therapy significantly improved glucose and lipid metabolism, reduced androgen levels, and addressed key endocrine disruptions. This combined therapy reduced ovarian collagen fiber formation and excessive autophagy, activating the PI3K/AKT/mTOR pathway. Additionally, it restored ovulation function, improved follicular quality, increased fertility rates, enhanced placental function, and reduced adverse pregnancy outcomes. Histological analysis showed increased ovarian microvessel density, enlarged placental labyrinth zone area, and normalized giant trophoblast cell arrangement in the treatment group. At the molecular level, MSCs and ML significantly decreased the expression of PI3K, Beclin1, P62, LC3 II/LC3I, and ROS in ovarian tissues, while upregulating p-mTOR, p-FOXO1, p-S6K1, and p-AKT expression. CONCLUSION: The combination of MSCs and ML inhibits excessive autophagy in ovarian granulosa cells and placental tissues of PCOS mice by regulating the PI3K/AKT/mTOR signaling pathway, while improving mitochondrial function, thereby restoring ovarian function and enhancing pregnancy outcomes. This study elucidates the role of the “autophagy-placental function” axis in PCOS pathogenesis, providing a new theoretical foundation and potential strategy for clinical PCOS treatment.