LncRNA FDNCR promotes apoptosis of granulosa cells by targeting the miR-543-3p/DCN/TGF-β signaling pathway in Hu sheep

Abstract Long non-coding RNAs (lncRNAs) regulate the development of follicles and reproductive diseases, but the mechanisms by which lncRNAs regulate ovarian functions and fertility remain elusive. We profiled the lncRNAs expression in the ovarian tissues of Hu sheep with different prolificacy and identified 21 327 lncRNAs. Many of lncRNAs were differentially expressed in different groups. We further characterized an lncRNA that was predominantly expressed in the ovaries of the low prolificacy FecB+ (LPB+) group and mainly present in granulosa cells (GCs) and expression decreased during follicular development, which named follicular development-associated lncRNA (FDNCR). Next, we found that FDNCR directly binds miR-543-3p and decorin (DCN) was identified as a target of miR-543-3p. FDNCR overexpression promoted GC apoptosis through increased expression of DCN, which could be attenuated by miR-543-3p. Furthermore, miR-543-3p increased and FDNCR reduced the expression of transforming growth factor-β (TGF-β) pathway-related genes, including TGF-β1 and inhibin beta A (INHBA), which were upregulated upon DCN silencing. Our results demonstrated that FDNCR sponges miR-543-3p in GCs and prevents miR-543-3p from binding to the DCN 3′-UTR, resulting in DCN transactivation and TGF-β pathway inhibition and promotion GC apoptosis in Hu sheep. These findings provide insights into the mechanisms underlying prolificacy in sheep.