Effects of Copper on Steroid Hormone Secretion, Steroidogenic Enzyme Expression, and Transcriptomic Profiles in Yak Ovarian Granulosa Cells.

Yak (Bos grunniens) is the main economic animal growing in the Qinghai-Tibet Plateau. Because of its poor growing environment, copper deficiency is common. Studies have shown that appropriate copper supplementation can improve the reproductive performance of heifers. In this study, the primary granulosa cells of yak were isolated, and different copper levels were established by adding copper chelator and copper sulfate. Biochemical, Western blot and transcriptome methods were used to reveal the mechanism of copper on the hormone secretion function of granulosa cells. The results showed that copper promoted hormone secretion by regulating the expression of steroid synthase such as StAR, CYP19A1 and CYP11A1. Transcriptome analysis showed that copper ion levels significantly affected the function of cells, and changes in copper ion level affected genes related to protein phosphorylation, lipid metabolism, lipid biosynthesis, steroid hormone synthesis and the MAPK pathway. In conclusion, copper can promote steroid hormone synthesis in the granulosa cells of yak follicles, and the MAPK signaling pathway may be involved.