Integrative Analysis of miRNA-mRNA in Ovarian Granulosa Cells Treated with Kisspeptin in Tan Sheep

Abstract

Kisspeptin is a peptide hormone encoded by the kiss-1 gene that regulates animal reproduction. Our studies revealed that kisspeptin can regulate steroid hormone production and promote cell proliferation in ovarian granulosa cells of Tan sheep, but the mechanism has not yet been fully understood. We speculated that kisspeptin might promote steroid hormone production and cell proliferation by mediating the expression of specific miRNA and mRNA in granulosa cells. Accordingly, after granulosa cells were treated with kisspeptin, the RNA of cells was extracted to construct a cDNA library, and miRNA-mRNA sequencing was performed. Results showed that 1303 expressed genes and 605 expressed miRNAs were identified. Furthermore, eight differentially expressed miRNAs were found, and their target genes were significantly enriched in progesterone synthesis/metabolism, hormone biosynthesis, ovulation cycle, and steroid metabolism regulation. Meanwhile, mRNA was significantly enriched in steroid biosynthesis, IL-17 signaling pathway, and GnRH signaling pathway. Integrative analysis of miRNA-mRNA revealed that the significantly different oar-let-7b targets eight genes, of which EGR1 (early growth response-1) might play a significant role in regulating the function of granulosa cells, and miR-10a regulates lipid metabolism and steroid hormone synthesis by targeting HNRNPD. Additionally, PPI analysis revealed genes that are not miRNA targets but crucial to other biological processes in granulosa cells, implying that kisspeptin may also indirectly regulate granulosa cell function by these pathways. The findings of this work may help understand the molecular mechanism of kisspeptin regulating steroid hormone secretion, cell proliferation, and other physiological functions in ovarian granulosa cells of Tan sheep.

Dynamic Expression of Follicle-Stimulating Hormone and Estrogen mRNA Receptors Associated with microRNAs 34a and -let-7c in Canine Follicles during the Estrous Cycle

“…MiR-let-7c is one of the earliest identified miRNAs [53], and its family members are highly conserved across species and the most abundant miRNAs in the ovary [54,55], suggesting that they have fundamental roles in reproductive physiology. Here, miR-let-7c was observed during all phases of the canine estrous cycle, which agrees with the presence of miR-let-7c in the ovine [56] and caprine [57] granulosa cells. The lowest miR-let-7c expression level was observed in the estrus phase, while the relative gene expression of ESR2, the predicted target of miR-let-7c, was the highest.…”

Role of Kisspeptin on the reproductive system of livestock and pet animals

“…Kp neuropeptide regulates the in vitro production of bovine embryos without the addition of LH and FSH (Soares et al, 2018). Downregulate of miRNA-1246 expression due to Kp, leads to the synthesis of progesterone in cattle (Guo et al, 2022) [52] .…”

“…The addition of other reproductive hormones (FSH, LH, and E2) in IVM media supplemented with oocytes clearly demonstrated that not only does Kp act on oocyte maturation but also rise the first polar body extrusion and cumulus cell expansion rate (Byri et al, 2017) [50] . The Kp-treated granulosa cell of RNA sequence revealed that expression of the different kinds of miRNA and mRNA is associated with the mechanism of steroid hormone regulation, cell proliferation, and physiological functions of ovarian granulosa cells in Tan sheep (Dai et al, 2022) [52] . The different kinds of doses and modes of Kp injection can change the gonadotropic hormone response and cause ovulation in noncyclical female ewes (Caraty et al, 2007) [51] .…”