Enhancing Gonadotrope Gene Expression Through Regulatory lncRNAs

Abstract

The world of long non-coding RNAs (lncRNAs) has opened up massive new prospects in understanding the regulation of gene expression. Not only are there seemingly almost infinite numbers of lncRNAs in the mammalian cell, but they have highly diverse mechanisms of action. In the nucleus, some are chromatin-associated, transcribed from transcriptional enhancers (eRNAs) and/or direct changes in the epigenetic landscape with profound effects on gene expression. The pituitary gonadotrope is responsible for activation of reproduction through production and secretion of appropriate levels of the gonadotropic hormones. As such, it exemplifies a cell whose function is defined through changes in developmental and temporal patterns of gene expression, including those that are hormonally-induced. Roles for diverse distal regulatory elements and eRNAs in gonadotrope biology have only just begun to emerge. Here, we will present an overview of the different kinds of lncRNAs that alter gene expression, and what is known about their roles in regulating some of the key gonadotrope genes. We will also review various screens that have detected differentially expressed pituitary lncRNAs associated with changes in reproductive state, and those whose expression is found to play a role in gonadotrope-derived non-functioning pituitary adenomas. We hope to shed light on this exciting new field, emphasize the open questions, and encourage research to illuminate the roles of lncRNAs in various endocrine systems.

Insight Into Pituitary lncRNA and mRNA at Two Estrous Stages in Small Tail Han Sheep With Different FecB Genotypes

“…To understand the regulatory mechanism of the follicular–luteal transition, a previous study focused mainly on the microRNA (miRNA)–mRNA interactions in ovarian tissue and revealed that some miRNAs, such as miR-200a, miR-200b, and miR-200c, appeared to be critical regulators of ovarian follicular and luteal development ( 53 , 54 ). However, pituitary hormones (FSH and LH) are required for the transition from the follicle to the corpus luteum, which involves receiving feedback signals from gonadal steroids and activin/inhibin signaling pathways ( 55 , 56 ). In our study, DEGs from the follicular–luteal transition of wild-type ewes were mainly enriched in the G2/M transition of mitotic cell cycle, response to BMP, and Wnt signaling pathway of the GO terms and tight junction, TGF-beta signaling pathway, circadian entrainment, gap junction, and hormone-related signaling pathways of the KEGG pathways.…”

Transcriptome analysis reveals mRNAs and long non-coding RNAs associated with fecundity in the hypothalamus of high-and low-fecundity goat

“…So far, the most intensive research on lncRNAs has focused on the level of ovarian tissue in the HPO axis, but little is known about its role in the hypothalamus and its mechanism of regulating reproductive hormones in goats, and the synergistic action of hypothalamus, pituitary and ovary can promote the moderate development of sexual organs and the formation of gametes ( 19 ). Previous studies have confirmed that the expression levels of certain genes in the hypothalamus directly or indirectly significantly affect reproductive activities such as follicle formation, follicular development and ovulation, while the ovulation rate of goats directly affects the fecundity of goats ( 20 ).…”