Expression of miR-21 and miR-93 in abattoir-derived bovine ovarian follicles

BACKGROUND: Cystic ovarian follicles (COF) are a major reproductive disorder in cows, leading to impaired fertility and substantial economic losses. The pathogenesis of COF is multifactorial and involves neuroendocrine dysregulation as well as local ovarian dysfunction. Increasing evidence suggests that microRNAs (miRNAs) play critical roles in follicular development and granulosa cell function. In this study investigated the expression levels of miR-21, miR-93, and BMPR2 in cystic ovarian follicles. The study examined healthy (n = 35) and cystic (n = 35) ovarian tissues. The aim of this study was to evaluate the expression levels of miR-21, miR-93, and BMPR2 in bovine cystic ovarian follicles and to investigate their potential association with the cystic ovarian condition. RESULTS: Histopathological evaluation confirmed characteristic degenerative changes in cystic follicles, including thinning and sparse cellularity of the granulosa layer and atrophic alterations of the theca layer. Quantitative real-time PCR analysis revealed significantly higher expression levels of miR-21 (p = 0.013) and miR-93 (p < 0.001) in cystic ovarian tissues compared with healthy controls, whereas BMPR2 expression did not differ significantly between groups (p = 0.725). Receiver operating characteristic (ROC) curve analysis demonstrated moderate discriminative power for miR-21 (AUC = 0.672) and high discriminative performance for miR-93 (AUC = 0.899). Correlation analysis showed a significant positive association between miR-93 and BMPR2 expression in the cystic group, while no significant correlations were observed in healthy ovaries. CONCLUSIONS: The findings indicate that miR-21 and miR-93 are upregulated in bovine cystic ovarian follicles, with miR-93 showing superior diagnostic potential compared with miR-21. The positive association between miR-93 and BMPR2 expression in cystic ovaries suggests a possible involvement of miR-93 in BMP-related regulatory pathways during cyst formation.