MicroRNA‑30d‑5p promotes ovarian granulosa cell apoptosis by targeting Smad2

Abstract

Polycystic ovarian syndrome (PCOS) is one of the leading causes of female infertility. MicroRNA-30d-5p (miR-30d-5p) has been reported to be significantly increased during follicle stimulating hormone (FSH)-mediated progesterone secretion of cultured granulosa cells. However, its role in the proliferation and apoptosis of ovarian granulosa cells is unclear. The present study aimed to investigate the role of miR-30d-5p in the proliferation and apoptosis of ovarian granulosa cells. Bioinformatic analysis and dual-luciferase reporter assay were used to predict and confirm the direct target of miR-30d-5p. The levels of miR-30d-5p were detected via reverse transcription-quantitative PCR (RT-qPCR), cell proliferation was detected via an MTT assay and cell apoptosis was measured via flow cytometry. The levels of phosphorylated (p)-Smad2, Smad2, p-Smad3 and Smad3 were detected by performing a western blot assay or RT-qPCR. In the present results, Smad2 was identified as the direct and functional target of miR-30d-5p. Compared with the control and control plasmid groups, the Smad2 plasmid significantly enhanced Smad2 mRNA levels in rat ovarian granulosa cells, enhanced rat ovarian granulosa cell viability and reduced cell apoptosis. In addition, the results demonstrated that overexpression of miR-30d-5p significantly decreased the level of Smad2, the effect of which was reversed by the Smad2-plasmid. Furthermore, it was demonstrated that the enhanced expression of miR-30d-5p significantly inhibited ovarian granulosa cell proliferation and promoted cell apoptosis. Restoration of Smad2 reversed the effect of miR-30d-5p on ovarian granulosa cell proliferation and apoptosis. Transfection with miR-30d-5p mimics significantly decreased the expression of Smad2 and increased the relative p-Smad2/Smad2 and p-Smad3/Smad3 levels in ovarian granulosa cells, which was reversed by overexpressing Smad2. The present study demonstrated that the overexpression of miR-30d-5p reduced proliferation and induced the apoptosis of granulosa cells by targeting Smad2. The molecular mechanism of ovarian granulosa cell apoptosis may therefore be explained by the newly identified miR-30d-5p/Smad2 axis, which represents a novel potential treatment target for PCOS.

rno-miR-128-3p promotes apoptosis in rat granulosa cells (GCs) induced by norepinephrine through Wilms tumor 1 (WT1)

“…After trans-activating by steroidogenic factor 1, miR-202-5p promotes apoptosis of goat GCs through regulating TGFβR2 (Ding et al 2020). And it finds that miR-30d-5p promotes GC apoptosis through suppressing Smad2 (Yu and Liu 2020). Likewise, our data demonstrated that inhibition of miR-128-3p repressed apoptosis in rat GCs induced by NE.…”

“…2020 ). And it finds that miR-30d-5p promotes GC apoptosis through suppressing Smad2 (Yu and Liu 2020 ). Likewise, our data demonstrated that inhibition of miR-128-3p repressed apoptosis in rat GCs induced by NE.…”

Rhamnocitrin Ameliorates Ovarian Fibrosis Via PPARγ/TGF-β1/Smad Pathway to Repair Ovarian Function in Polycystic Ovary Syndrome Rats Running Title：rhamnocitrin Ameliorates Ovarian Fibrosis in Polycystic Ovary Syndrome Rats

“…The decreased bioavailability of TGF-β1 is correlated with an improvement in some abnormal clinical parameters of PCOS [40]. Enhanced Smad2 level by plasmid can reduce apoptosis and improve cell viability of rat ovarian granulosa cells [41]. TGF-β1/Smad3 pathway regulates apoptosis of granulosa cells, through inhibiting ovarian follicle development of PCOS [42].…”

miR‐221‐3p regulates apoptosis of ovarian granulosa cells via targeting FOXO1 in older women with diminished ovarian reserve (DOR)

“…Besides, numerous studies have reported on the role of different miRNAs in GCs apoptosis in PCOS. Some miRNAs inhibit apoptosis, such as miR‐129 (Zhu et al, 2020), miR‐17‐5p (G. Liu et al, 2020), miR‐33b, and miR‐142 (Y. Li et al, 2019), whereas others promote apoptosis, including miR‐423 (Y. Li et al, 2019), miR‐30d‐5p (Yu & Liu, 2020), miR‐135a (Wei et al, 2020), and miR‐204 (X. Sun et al, 2019).…”