Pyrroloquinoline quinone promotes human mesenchymal stem cell-derived mitochondria to improve premature ovarian insufficiency in mice through the SIRT1/ATM/p53 pathway.

BACKGROUND: DNA damage and oxidative stress induced by chemotherapy are important factors in the onset of premature ovarian insufficiency (POI). Studies have shown that mitochondria derived from mesenchymal stem cells (MSC-Mito) are beneficial for age-related diseases, but their efficacy alone is limited. Pyrroloquinoline quinone (PQQ) is a potent antioxidant with significant antiaging and fertility enhancement effects. This study aimed to investigate the therapeutic effect of MSC-Mito in combination with PQQ on POI and the underlying mechanisms involved. METHODS: A POI animal model was established in C57BL/6J mice by cyclophosphamide and busulfan. The effects of MSC-Mito and PQQ administration on the estrous cycle, ovarian pathological damage, sex hormone secretion, and oxidative stress in mice were evaluated using methods such as vaginal smears and ELISAs. Western blotting and immunohistochemistry were used to assess the expression of SIRT1, PGC-1α, and ATM/p53 pathway proteins in ovarian tissues. A cell model was constructed using KGN cells treated with phosphoramide mustard to investigate DNA damage and apoptosis through comet assays and flow cytometry. SIRT1 siRNA was transfected into KGN cells to further explore the role of the SIRT1/ATM/p53 pathway in combination therapy with MSC-Mito and PQQ for POI. RESULTS: The combined treatment of MSC-Mito and PQQ significantly restored ovarian function and antioxidant capacity in mice with POI. This treatment also reduced the loss of follicles at various stages, improving the disrupted estrous cycle. In vitro experiments demonstrated that PQQ facilitated the proliferation of MitoTracker-labelled MSC-Mito, synergistically restoring mitochondrial function and inhibiting oxidative stress in combination with MSC-Mito. Both in vivo and in vitro, the combination of MSC-Mito and PQQ increased mitochondrial biogenesis mediated by SIRT1 and PGC-1α while inhibiting the activation of ATM and p53, consequently reducing DNA damage-mediated cell apoptosis. Furthermore, pretreatment of KGN cells with SIRT1 siRNA reversed nearly all the aforementioned changes induced by the combined treatment. CONCLUSIONS: Our research findings indicate that PQQ facilitates MSC-Mito proliferation and, in combination with MSC-Mito, ameliorates chemotherapy-induced POI through the SIRT1/ATM/p53 signaling pathway.

Eukaryotic Initiation Factor 3C Can Affect the Proliferation and Invasion of Ovarian Cancer by Regulating the p53 Signalling Pathway.

BACKGROUND: Eukaryotic Initiation Factor 3C (EIF3C) represents a pivotal translational initiation factor in eukaryotes and has been shown to facilitate the progression of various neoplasms. However, its mechanistic role in ovarian cancer remains elusive. METHODS: In this research, the expression of EIF3C in ovarian cancer tissues was investigated using immunohistochemistry. In addition, the assessments were made on changes in cellular proliferation, invasion, and apoptotic abilities by reducing the expression of EIF3C in ovarian cancer cells. By utilizing microarray analysis, a comparison was performed between the downregulated EIF3C group and the control group of ovarian cancer cells, revealing the genes that were expressed differently. Furthermore, the signalling pathways associated with cellular proliferation were validated. The functional role of EIF3C in vivo was investigated using a xenograft tumour model. RESULTS: The immunohistochemical analysis showed that elevated levels of EIF3C are linked to a negative prognosis in patients with ovarian cancer. Suppression of EIF3C greatly hindered the growth and spread of SK-OV-3 and HO-8910 cells while enhancing cellular programmed cell death. Following KEGG and GSEA enrichment analyses of differentially expressed genes, the p53 signalling pathway was found to be associated with EIF3C. Suppression of EIF3C resulted in the upregulation of the p53 signalling pathway, leading to the inhibition of cell proliferation and invasion and the promotion of apoptosis. In vivo experiments demonstrated that EIF3C knockdown suppressed the growth of subcutaneous tumours in nude mice. CONCLUSION: There is a correlation between overexpression of EIF3C in tumour tissues of ovarian cancer patients and this is associated with a poorer prognosis. By influencing the p53 signaling pathway, EIF3C facilitates the growth and infiltration of cells in ovarian cancer.