Mechanism of ferroptosis in a rat model of premature ovarian insufficiency induced by cisplatin.

Ferroptosis is widely present in fibrosis-related diseases. The basic pathology of premature ovarian insufficiency (POI) involves ovarian tissue fibrosis, and there are currently fewer relevant studies addressing the association between ferroptosis and POI. This study aimed to demonstrate that ferroptosis induced by cisplatin (CDDP) caused ovarian tissue fibrosis, leading to POI. Vitamin E (VE), a ferroptosis inhibitor, could repair damaged ovarian function. CDDP was used to establish a rat model of POI, and VE was administered to reverse the reproductive toxicity of CDDP. Ovarian function was assessed by histological section staining, follicle counts, sex hormone levels, as well as fertility assays. The extent of ferroptosis was assessed by transmission electron microscopy (TEM), malondialdehyde (MDA), Perls staining. CCK-8, Ethynyl-2-Deoxyuridine (EdU), and scratch assays were used to determine the effect of CDDP and VE on ovarian granulosa cell (GC) viability. Western blot, quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry were performed to evaluate ferroptosis-related molecular changes. Our results showed that CDDP caused follicle development disorders and ovarian tissue fibrosis, the levels of sex hormones suggested impaired ovarian function, and VE could reverse the reproductive toxicity of CDDP. The results of TEM, MDA and Perls staining suggested that the typical mitochondrial signature of ferroptosis was altered in ovarian GCs from the CDDP group, with significantly higher levels of lipid peroxidation and significant iron deposition in ovarian tissue, whereas VE mitigated the extent of ferroptosis. Molecular experiments then confirmed that the ferroptosis-related molecules acetyl CoA synthetase long chain family member 4 (ACSl4), 15-lipoxygenase-1 (ALOX15), solute carrier family 7 member 11 (SLC7A11), and glutathione peroxidase 4 (GPX4) were differentially expressed in each group. In summary, our study preliminarily demonstrated that CDDP may promote GCs to undergo ferroptosis, cause follicle development disorders, ovarian tissue fibrosis, and induce POI by regulating the expression of ACSl4, ALOX15, SLC7A11, and GPX4, while VE improved impaired ovarian function.