LncRNA NEAT1 inhibits apoptosis and autophagy of ovarian granulosa cells through miR-654/STC2-mediated MAPK signaling pathway.

ABSTRACT

Long non-coding RNA (lncRNA) anomalies cause early ovarian failure. LncRNA nuclear enriched abundant transcript 1 (NEAT1) was down-regulated in premature ovarian failure (POF) mice and connected to the illness, however, the mechanism remained unclear. The levels of gene and protein were measured by using quantitative real-time polymerase chain reaction, Western blot, and immunofluorescence. Follicle stimulating hormone (FSH), estradiol (E2), and luteinizing hormone (LH) levels were determined using enzyme-linked immunosorbent assay (ELISA). 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and flow cytometry were used to determine cell viability and apoptosis. The interaction of NEAT1, miR-654, and stanniocalcin-2 (STC2) was verified by dual-luciferase reporter assay or RNA binding protein immunoprecipitation (RIP) assays. The results showed NEAT1 and STC2 down-regulated, while miR-654 up-regulated in POF mice. Overexpression of NEAT1 reduced apoptosis and autophagy in cyclophosphamide (CTX)-treated ovarian granulosa cells (OGCs), and Bax, cleaved-caspase3, LC3B, LC3II/LC3I ratio were decreased and Bcl-2 and p62 were raised. NEAT1 suppressed miR-654 expression by directly targeting miR-654. The inhibition of NEAT1 overexpression on apoptosis and autophagy in OGCs was reversed by miR-654 mimics. STC2 was a target gene of miR-654, and miR-654 inhibitor reduced the apoptosis and autophagy by regulating the STC2/MAPK axis. To sum up, NEAT1 reduced miR-654 expression and modulated the STC2/MAPK pathway to decrease apoptosis and autophagy in POF, indicating a potential therapeutic target.