Circular RNA ciR-02852: A novel physiological inhibitor of Porcine ovarian granulosa cell functions

Circular RNAs (circRNAs) are stable epigenetic regulators of various biological processes, yet the functional role of ciR-02852 remains unknown. This study aimed to characterize the influence of ciR-02852 on the fundamental functions of porcine ovarian granulosa cells. Cells were transfected with either a ciR-02852-overexpressing vector or an shRNA ciR-02852-knockdown vector. We assessed cell viability, proliferation markers (PCNA, cyclin B1), apoptosis markers (Bax, caspase-3, and DNA fragmentation), and the secretion of steroid (progesterone, testosterone, estradiol) and peptide (IGF-I, oxytocin) hormones via RT-qPCR, immunocytochemistry, TUNEL, and ELISA. Overexpression of ciR-02852 significantly reduced cell viability and the expression of PCNA and cyclin B1. Conversely, it stimulated both cytoplasmic and nuclear apoptosis, as evidenced by increased Bax, caspase-3, and DNA fragmentation. Furthermore, ciR-02852 overexpression inhibited the release of all measured hormones. Silencing of ciR-02852 via shRNA yielded the opposite effects, promoting proliferation and hormone output while suppressing apoptosis. These findings demonstrate for the first time that ciR-02852 acts as a potent physiological inhibitor of porcine ovarian cell functions. Our results indicate that ciR-02852 could be a multi-target regulator of folliculogenesis and hormone production, highlighting its potential as a diagnostic marker or therapeutic target for managing reproductive disorders and improving animal production.