miRNA-novel-216 regulated fatty acid composition and progesterone synthesis in goat granulosa cells by targeting the TPD52

Granulosa cells in the ovaries of livestock are crucial for secreting steroid hormones that regulate follicular development, with lipid synthesis and metabolism playing key roles in this process. The molecular mechanisms behind steroid hormone secretion regulated by fatty acid metabolism in goat granulosa cells have been unclear. Our previous transcriptome analysis of Yunshang black goat ovaries revealed that miR-novel-216, which had lower expression in high-fertility goats, might regulate granulosa cell function. We further investigated the role of miR-novel-216 by isolating and culturing goat granulosa cells in vitro and found that it inhibits cell proliferation, lipid accumulation and progesterone synthesis in goat granulosa cells. The qTar and miRanda analyses predicted TPD52 as a target of miR-novel-216, confirmed by dual luciferase and transfection assays. Previous studies have shown that progesterone synthesis in granulosa cells is closely related to free fatty acid composition. We investigated the effect of in vitro construction of TPD52 overexpression and interference plasmids on the free fatty acid content of goat granulosa cells using mass spectrometry sequencing. The results showed that the overexpression of TPD52 in goat granulosa cells significantly increased the free fatty acid content and promoted granulosa cell proliferation, lipid accumulation and progesterone synthesis, whereas the opposite was true for inhibition of TPD52. It was shown that miR-novel-216 affects granulosa cell proliferation and free fatty acid levels by regulating the expression of TPD52, which increases reproductive hormone secretion and promotes polytocous trait in goats. This provides a foundation for developing breeding strategies to improve goat fertility.