MiR-126-3p inhibits apoptosis and promotes proliferation by targeting phosphatidylinositol 3-kinase regulatory subunit 2 in porcine ovarian granulosa cells

Abstract

Objective: Numerous studies have indicated that the apoptosis and proliferation of granulosa cells (GCs) are closely related to the normal growth and development of follicles and ovaries. Previous evidence has suggested that miR-126-3p might get involved in the apoptosis and proliferation of GCs, and phosphatidylinositol 3-kinase regulatory subunit 2 (<i>PIK3R2</i>) gene has been predicted as one target of miR-126-3p. However, the molecular regulation of miR-126-3p on <i>PIK3R2</i> and the effects of <i>PIK3R2</i> on porcine GCs apoptosis and proliferation remain virtually unexplored.Methods: In this study, using porcine GCs as a cellular model, luciferase report assay, mutation and deletion were applied to verify the targeting relationship between miR-126-3p and <i>PIK3R2</i>. Annexin-V/PI staining and 5-ethynyl-2’-deoxyuridine assay were applied to explore the effect of <i>PIK3R2</i> on GCs apoptosis and proliferation, respectively. Real-time quantitative polymerase chain reaction and Western Blot were applied to explore the regulation of miR-126-3p on <i>PIK3R2</i> expression.Results: We found that miR-126-3p targeted at <i>PIK3R2</i> and inhibited its mRNA and protein expression. Knockdown of <i>PIK3R2</i> significantly inhibited the apoptosis and promoted the proliferation of porcine GCs, and significantly down-regulated the mRNA expression of several key genes of PI3K pathway such as insulin-like growth factor 1 receptor (<i>IGF1R</i>), insulin receptor (<i>INSR</i>), pyruvate dehydrogenase kinase 1 (<i>PDK1</i>), and serine/threonine kinase 1 (<i>AKT1</i>).Conclusion: MiR-126-3p might target and inhibit the mRNA and protein expressions of <i>PIK3R2</i>, thereby inhibiting GC apoptosis and promoting GC proliferation by down-regulating several key genes of the PI3K pathway, <i>IGF1R</i>, <i>INSR</i>, <i>PDK1</i>, and <i>AKT1</i>. These findings would provide great insight into further exploring the molecular regulation of miR-126-3p and <i>PIK3R2</i> on the functions of GCs during the folliculogenesis in female mammals.

miR-126-3p containing exosomes derived from human umbilical cord mesenchymal stem cells promote angiogenesis and attenuate ovarian granulosa cell apoptosis in a preclinical rat model of premature ovarian failure

“…In addition, we further demonstrated that miR-126-3p down-regulate PIK3R2 expression through post-transcriptional regulation by binding to the sequence in the 3' untranslated region of PIK3R2. Interestingly, in line with our study, another study by Xiaofeng Zhou showed that miR-126-3p were able to inhibit apoptosis by targeting PIK3R2 in porcine OGCs, which supports the results of this study [ 21 ].…”

Transcriptome Profiling of Goose Ovarian Follicle Granulosa Cells Reveals Key Regulatory Networks for Follicle Selection

“…Like miR-222-3p, miR-126-5p is also associated with PCOS [ 22 , 23 ]. Studies in rats and pigs have shown that miR-126-5p in ovarian granulosa cells promotes vascular growth and inhibits apoptosis [ 24 , 25 , 26 ]. There is limited research on the role of miR-2954 in reproduction.…”

miR-126 Controls the Apoptosis and Proliferation of Immature Porcine Sertoli Cells by Targeting the PIK3R2 Gene through the PI3K/AKT Signaling Pathway

“…Additionally, miR-126 negatively regulated PIK3R2 protein expression in immature porcine Sertoli cells. It has been widely reported that miR-126 targets the PIK3R2 gene and represses its expression through a conserved binding site in a diverse group of animal species [ 13 , 33 , 34 ]. Previous studies have demonstrated that the PIK3R2 gene, a member of the PI3K family, encodes p85β, an enzyme involved in the production of 3-polyphosphoinositides [ 35 ].…”