Abstract: BACKGROUND: Studies have demonstrated that specific microRNAs (miRNAs) exhibit significant downregulation in a rat model of premature ovarian failure, and their overexpression can effectively alleviate symptoms of premature ovarian failure. Therefore, investigating miRNAs as potential auxiliary biomarkers holds substantial academic and clinical significance, offering a more stable and reliable reference for the diagnosis of premature ovarian failure. 
OBJECTIVE: To investigate whether the expression patterns of six miRNAs in ovarian tissue from animal models of premature ovarian failure and in peripheral blood from patients with premature ovarian failure are consistent, and to validate the clinical diagnostic potential of these six miRNAs.
METHODS: (1) Twenty Wistar rats were randomly divided into a normal group (n=10) and a premature ovarian failure group (n=10). The model of premature ovarian failure was established in the premature ovarian failure group by intraperitoneal injection of cisplatin [1 mg/(kg·d)] for 14 continuous days. Following modeling, serum samples were collected from both groups. Levels of follicle-stimulating hormone, estradiol, and anti-Müllerian hormone were measured using ELISA. Ovarian tissue morphology was examined via hematoxylin-eosin staining. Q-PCR was used to detect the expression of miR-10a-5p, miR-21-5p, miR-22-3p, miR-126-3p, miR-144-3p, and miR-144-5p in ovarian tissue. (2) Ten patients with premature ovarian failure and ten healthy female controls, all aged < 40 years, were enrolled. Chemiluminescence assays measured the levels of follicle-stimulating hormone, estradiol, and anti-Müllerian hormone in peripheral blood from both groups. Q-PCR was used to detect the expression of miR-10a-5p, miR-21-5p, miR-22-3p, miR-126-3p, miR-144-3p, and miR-144-5p in peripheral blood. The effect size and diagnostic performance of these six miRNAs in human blood samples were systematically evaluated using receiver operating characteristic curves.
RESULTS AND CONCLUSION: (1) Compared with the normal group, rats with premature ovarian failure showed significantly elevated follicle-stimulating hormone level and reduced estradiol and anti-Müllerian hormone levels. Hematoxylin-eosin staining revealed a significant decrease in the number of follicles in the ovaries of rats with premature ovarian failure compared with the normal group. The expression of miR-10a-5p, miR-21-5p, miR-22-3p, miR-126-3p, miR-144-3p, and miR-144-5p was markedly downregulated in the ovaries of rats with premature ovarian failure compared with the normal group (P < 0.05). (2) Compared with healthy controls, patients with premature ovarian failure exhibited elevated levels of follicle-stimulating hormone in peripheral blood (P < 0.05), along with decreased levels of estradiol and anti-Müllerian hormone (P < 0.05). Q-PCR assay revealed that, compared with healthy controls, patients with premature ovarian failure exhibited downregulated expression of miR-10a-5p, miR-21-5p, miR-22-3p, miR-126-3p, miR-144-3p, and miR-144-5p in peripheral blood (P < 0.05). The receiver operating characteristic curves demonstrated that all six miRNAs exhibited excellent diagnostic discrimination capabilities (sensitivity: 100%, specificity: 100%), indicating their clinical potential as highly specific molecular biomarkers for premature ovarian failure. These findings indicate that these six miRNAs may serve not only as promising biomarkers for premature ovarian failure but also as clinically valuable tools.

Key words: premature ovarian failure;, miRNAs, exosomes, extracellular vesicles, peripheral blood, animal model, patients with premature ovarian failure, tissue construction