Differentially expressed lncRNA-m433s1 regulates FSH secretion by functioning as a miRNA sponge in male rat anterior pituitary cells†.

Long noncoding RNAs (lncRNAs) are important regulators that have multiple functions in a variety of biological processes. However, the contributions of lncRNAs to follicle-stimulating hormone (FSH) secretion remain largely unknown. In this study, we first identified a novel lncRNA, lncRNA-m433s1, as an intergenic lncRNA located in the cytoplasm. We next used MS2-RIP assays to demonstrate that lncRNA-m433s1 interacted with miR-433. Furthermore, we detected the levels of lncRNA-m433s1, miR-433, and Fshß expression, FSH concentrations, and apoptosis upon overexpression and knockdown of lncRNA-m433s1, revealing that lncRNA-m433s1 upregulated Fshß expression. Globally, lncRNA-m433s1 reduced the inhibitory effect of miR-433 on Fshß and further regulated FSH secretion as a competing endogenous RNA (ceRNA) by sponging miR-433. This ceRNA model will provide novel insight into the regulatory mechanisms of lncRNAs associated with rat reproduction.

Roles of differential expression of miR-543-5p in GH regulation in rat anterior pituitary cells and GH3 cells.

Growth hormone (GH) is an important hormone released by the pituitary gland that plays a key role in the growth and development of organisms. In our study, TargetScan analysis and the dual luciferase reporter assays were used to predict and screen for miRNAs that might act on the rat Gh1 gene, and we identified miR-543-5p. Then, the GH3 cell line and the primary rat pituitary cells were transfected with miRNA mimic, inhibitor, and siRNA. We detected the Gh1 gene expression and the GH secretion by real-time PCR and ELISAs, respectively, to verify the regulatory effect of miR-543-5p on GH secretion. The results showed that miR-543-5p can inhibit Gh1 mRNA expression and reduce GH secretion. MiR-543-5p inhibitor upregulated Gh1 mRNA expression and increased GH secretion compared with the negative control. In summary, miR-543-5p downregulates Gh1 expression, resulting in a decrease in GH synthesis and secretion, which demonstrates the important role of miRNAs in regulating GH and animal growth and development.

Pituitary tissue-specific miR-7a-5p regulates FSH expression in rat anterior adenohypophyseal cells.

The follicle-stimulating hormone (FSH), which is synthesized and secreted by the anterior pituitary gland, plays an important role in regulating reproductive processes. In this study, using the TargetScan program, we predicted that microRNAs (miRNAs) regulate FSH secretion. Dual-luciferase reporter assays were performed and identified miR-7a-5p. MiR-7a-5p has been reported to regulate diverse cellular functions. However, it is unclear whether miR-7a-5p binds to mRNAs and regulates reproductive functions. Therefore, we constructed a suspension of rat anterior pituitary cells and cultured them under adaptive conditions, transfected miR-7a-5p mimics or inhibitor into the cell suspension and detected expression of the FSHb gene. The results demonstrated that miR-7a-5p downregulated FSHb expression levels, while treatment with miR-7a-5p inhibitors upregulated FSHb expression levels relative to those of negative control groups, as shown by quantitative PCR analysis. The results were confirmed with a subsequent experiment showing that FSH secretion was reduced after treatment with mimics and increased in the inhibitor groups, as shown by enzyme-linked immunosorbent assay. Our results indicated that miR-7a-5p downregulates FSHb expression levels, resulting in decreased FSH synthesis and secretion, which demonstrates the important role of miRNAs in the regulation of FSH and animal reproduction.