Differentially expressed IGF2BP2 in ovarian disorders: strongly associates with alternative splicing regulation in human granulosa cells

Abstract

Genome-wide interactions between RNA-binding proteins (RBPs) and RNA targets account for an important portion of post-transcriptional regulation. IGF2BP2 is associated with type 2 diabetes (T2D) and obesity and reportedly functions as an RBP that regulates a series of target genes by binding RNA transcripts. In this study, we detected the differential expression of IGF2BP2 in granulosa cells from women with ovarian disorders and performed RNA-seq and RIP-seq experiments in immortalized human granulosa cells (KGN cells) to evaluate global transcript levels and alternative splicing on KGN cells overexpressing IGF2BP2 versus controls. Our results show that IGF2BP2 preferentially binds to the 3’and 5’UTRs of mRNAs and enriches target gene expression in KGN cells. Notably, besides the conventional GGAC motif, we found a significant enrichment of a new GAAG motif within IGF2BP2-binding regions. We demonstrate that IGF2BP2 is involved in transcription regulation and alternative splicing in genes associated with follicular development. Furthermore, IGF2BP2 partly influences the expression levels of some of these alternatively spliced genes, including MBD3 and FN1, which may lead to ovarian endocrine disorders. In conclusion, we provide a transcriptome-wide analysis that demonstrates the role played by IGF2BP2 in the regulation of gene expression, transcription and alternative splicing of a number of genes involved in the pathogenesis of ovarian endocrine diseases.

LH/hCG Regulation of Circular RNA in Mural Granulosa Cells during the Periovulatory Period in Mice

“…IGF2BP1 regulates GCs viability, cell cycle, and cell proliferation through the m6A-dependent mRNA stability of the MDM2 gene [39]. IGF2BP2 regulates the transcription and alternate splicing of genes involved in follicular development, such as MBD3, FN1, TFDP1, and MKNK2 [40]. In total, the identified RBPs associated with the identified mural granulosa cell circRNA have a robust and well-established role in ovarian physiology.…”

“…In addition, we determined that the LH surge elicited a rapid change (within 4-h) in the abundance of a small number of RNA transcripts, most of which increased. Subsequent bioinformatic analyses of these selected circRNA indicated that they had the ability to bind to a small number of enriched proteins and miRNA partners related to processes well known to be critical in the growth/development and maturation of the ovarian follicle [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40]. These initial studies open up a new area of scientific investigation regarding understanding the molecular mechanisms underlying the ovulatory gonadotropin-induced ovarian surge, which might ultimately help us understand human fertility and infertility.…”