A miRNA target network putatively involved in follicular atresia

Abstract

In a previous microarray study, we identified a subset of micro RNAS (miRNAs), which expression was distinctly higher in atretic than healthy follicles of cattle. In the present study, we investigated the involvement of those miRNAs in granulosa and theca cells during atresia. Reverse Transcription-quantitative Polymerase Chain Reaction (RT-qPCR) confirmed that miR-21-5p/-3p, miR-150, miR-409a, miR-142-5p, miR-378, miR-222, miR-155, and miR-199a-5p were expressed at higher levels in atretic than healthy follicles (9–17 mm, classified based on steroidogenic capacity). All miRNAs except miR-21-3p and miR-378 were expressed at higher levels in theca than granulosa cells. The expression of 13 predicted miRNA targets was determined in follicular cells by RT-qPCR, revealing downregulation of HIF1A, ETS1, JAG1, VEGFA, and MSH2 in either or both cell types during atresia. Based on increases in miRNA levels simultaneous with decreases in target levels in follicular cells, several predicted miRNA target interactions were confirmed that are putatively involved in follicular atresia, namely miR-199a-5p/miR-155-HIF1A in granulosa cells, miR-155/miR-222-ETS1 in theca cells, miR-199a-5p-JAG1 in theca cells, miR-199a-5p/miR-150/miR-378-VEGFA in granulosa and theca cells, and miR-155-MSH2 in theca cells. These results offer novel insight on the involvement of miRNAs in follicle development by identifying a miRNA target network that is putatively involved in follicle atresia.

miR-21 and Pellino-1 Expression Profiling in Autoimmune Premature Ovarian Insufficiency

“…Karakaya et al [24] conducted a miRNA microarray in cumulus cells, and the elevated expressions of miR-21-5p/-3p were observed. Additionally, Donadeu et al [25] used qRT-PCR to confirm the involvement of highly expressed miR-21-5p/-3p in granulosa and theca cells during follicle atresia. In our study, we showed the lower expression of miR-21 in both autoimmune POI patients and mouse models compared with that in the control subjects.…”

Roles of microRNAs in mammalian reproduction: from the commitment of germ cells to peri‐implantation embryos

“…Another panel of miRNAs including miR‐125b, miR‐145, and miR‐199a‐3p target leukemia inhibitory factor ( LIF ), cyclin dependent kinase inhibitor 1A ( CDKN1A ), and prostaglandin‐endoperoxide synthase 2 ( PTGS2 ), respectively, in GCs, but not in TCs of bovine follicles (Donadeu et al, ). Furthermore, a panel of miRNAs is highly expressed in atretic follicles compared to healthy follicles, with all miRNAs except miR‐21‐3p and miR‐378 showing higher expression in TCs compared to GCs (Donadeu, Mohammed, & Ioannidis, ). This suggests that these miRNAs might regulate the phenotypic characters of different cell types by controlling the expression of important signalling molecules (Donadeu et al, ).…”

“…Similarly, miR‐143 inhibits the proliferation of pregranulosa cells in mice by regulating Cdks , Ccnb1 , Ccnd2 , and Ccne2 , and thus inhibits the formation of primordial follicles (Zhang et al, ). In cattle, miR‐21‐5p, miR‐21‐3p, miR‐222, miR‐155, and miR‐199a‐5p are upregulated in atretic follicles compared to healthy follicles (Donadeu et al, ). Another two miRNAs, miR‐378 and miR‐21‐5p, were increased in subordinate and anovulatory follicles in horses (Donadeu & Schauer, ; Schauer et al, ).…”

“…Furthermore, a panel of miRNAs is highly expressed in atretic follicles compared to healthy follicles, with all miRNAs except miR-21-3p and miR-378 showing higher expression in TCs compared to GCs (Donadeu, Mohammed, & Ioannidis, 2017). This suggests that these miRNAs might regulate the phenotypic characters of different cell types by controlling the expression of important signalling molecules (Donadeu et al, 2017). Additionally, miR-708, miR-221, miR-21-3p, miR-335, and miR-214 are expressed abundantly in the follicular fluid of SFs compared to that of DFs (Gebremedhn et al, 2015) indicating a potential role in the selection of follicles.…”

MicroRNAs regulate granulosa cells apoptosis and follicular development — A review

“…Currently, it has been reported that the specific miRNA families and clusters are involved in follicular atresia and development including miR-21, miR-23a, miR-145, miR-503, miR-224, miR-383, miR-378, miR-132, miR-212, the let-7 family, miR-17-92 cluster, miR-23-27-24 cluster, miR-183-96-182cluster, miR-17-92 cluster and so on(28,65,67,68). However, it has been undetermined which miRNA cluster(s) are associated with the each stage of FD(62,64,65). Furthermore, actual roles of these miRNA clusters in the FD, atresia and ovulation remain unclear(8,43,69).Fifteen different miRNAs were found during the growth and selection of dominant follicles(70).Six miRNAs, including miR-17, miR-18a, miR-19a, miR-20a, miR19b and miR-92a, are encoded by a single miR-17-92 transcript (71), and are expressed and processed together as a cluster (64).…”