miR-202-5p Inhibits Lipid Metabolism and Steroidogenesis of Goose Hierarchical Granulosa Cells by Targeting ACSL3

SIMPLE SUMMARY: Poultry laying performance depends on the normal development of ovarian follicles. Lipid metabolism and steroidogenesis in granulosa cells are essential for maintaining normal follicular development; therefore, a detailed understanding of the molecular mechanisms underlying granulosa cell functions may provide a basis for improving production. In the present study, we investigated the effects of miR-202-5p, which show expression changes during follicular development, on lipid metabolism and steroidogenesis in goose hierarchical follicular granulosa cells. We found that miR-202-5p significantly inhibited lipid deposition and steroid hormone production in goose hierarchical follicles granulosa cells via ACSL3. These results revealed the important role of miR-202-5p in the regulation of goose granulosa cell functions and demonstrate that this miRNA is a potential target for molecular breeding. ABSTRACT: miRNAs are critical for steroidogenesis in granulosa cells (GCs) during ovarian follicular development. We have previously shown that miR-202-5p displays a stage-dependent expression pattern in GCs from goose follicles of different sizes, suggesting that this miRNA could be involved in the regulation of the functions of goose GCs; therefore, in this study, the effects of miR-202-5p on lipid metabolism and steroidogenesis in goose hierarchical follicular GCs (hGCs), as well as its mechanisms of action, were evaluated. Oil Red O staining and analyses of intracellular cholesterol and triglyceride contents showed that the overexpression of miR-202-5p significantly inhibited lipid deposition in hGCs; additionally, miR-202-5p significantly inhibited progesterone secretion in hGCs. A bioinformatics analysis and luciferase reporter assay indicated that Acyl-CoA synthetase long-chain family member 3 (ACSL3), which activates long-chain fatty acids for the synthesis of cellular lipids, is a potential target of miR-202-5p. ACSL3 silencing inhibited lipid deposition and estrogen secretion in hGCs. These data suggest that miR-202-5p exerts inhibitory effects on lipid deposition and steroidogenesis in goose hGCs by targeting the ACSL3 gene.