MiR199a was found to be differentially expressed in rat uteri between the prereceptive and receptive phase via microRNA (miRNA) microarray analysis in our previous study. However, the role of miR199a in rat embryo implantation remained unknown. In the study, northern blot results showed that the expression levels of miR199a were higher on gestation days 5 and 6 (g.d.5–6) in rat uteri than on g.d.3–4 and g.d.7–8. In situ localization of miR199a in rat uteri showed that miR199a was mainly localized in the stroma or decidua. The expression of miR199a was not significantly different in the uteri of pseudopregnant rats and evidently increased in the uteri of rats subjected to activation of delayed implantation and experimentally induced decidualization. Treatment with 17β-estradiol or both 17β-estradiol and progesterone significantly diminished miR199a levels. Gain of function of miR199a in endometrial stromal cells isolated from rat uteri inhibited cell proliferation and promoted cell apoptosis. Loss of function of miR199a displayed opposite roles on cell proliferation and apoptosis. Further investigation uncovered a significant inverse association between the expression of miR199a and growth factor receptor-bound protein 10 (Grb10), an imprinted gene, and miR199a could bind to the 3′UTR of Grb10 to inhibit Grb10 translation. In addition, in vivo analysis found that the immunostaining of GRB10 was attenuated in the stroma or decidua from g.d.4 to 6, contrary to the enhancement of miR199a. Collectively, upregulation of miR199a in rat uterus during the receptive phase is regulated by blastocyst activation and uterine decidualization. Enforced miR199a expression suppresses cell proliferation partially through targeting Grb10.
Hong-Fei Xia, Jing-Li Cao, Xiao-Hua Jin and Xu Ma
Xing Su, Yi Hu, Ying Li, Jing-Li Cao, Xue-Qin Wang, Xu Ma and Hong-Fei Xia
Although the relationship between polymorphisms in microRNAs (miRNAs) and recurrent pregnancy loss (RPL) has been studied, there is very little data available in the literature. In the present study, we scanned 55 potentially functional polymorphisms in the miRNA coding region in Chinese women with unexplained RPL (URPL; no. 2011-10). The rs6505162 C>A in the MIR423 coding region was found to be significantly associated with the occurrence of human URPL. The rare A allele contributed to an increase in the expression of mature MIR423. C to A substitution in the polymorphism rs6505162 in pre-MIR423 repressed cell proliferation and migratory capacity. Further investigations showed that MIR 423 could inversely regulate the expression of proliferation-associated 2 group 4 (PA2G4) by binding the 3′-UTR of PA2G4. Dual-luciferase assay indicated that the A allele in the polymorphism rs6505162 could more effectively suppress the expression of PA2G4 than the C allele could. Collectively, the present data suggest that rs6505162 C>A in pre-MIR423 may contribute to the genetic predisposition to RPL by disrupting the production of mature MIR42 3 and its target gene, which consequently interferes with MIR423 functioning.
Qi Zhu, Yi-Chao Dong, Lu Zhang, Xu Ma and Hong-Fei Xia
Missed abortion (MA) is a common disease in obstetrics and gynecology. More and more studies have focused on the relationship between miRNAs and pregnancy maintenance and its related diseases. The aim of this article is to explore the relationship between miRNA and MA. The expression of miR-98 were detected by in situ hybridization and real-time PCR. Cell proliferation, activity and migration were measured via Edu, MTT, and transwell assays. The target genes of miR-98 are identified by dual-luciferase activity assay. And the expression levels of target genes were determined by Western blot, real-time PCR and immunohistochemistry. miR-98 was significantly up-regulated in placental villi from over 35 years old MA patients compared with the age-matched normal pregnant women. Up-regulation of miR-98 suppressed the proliferation, activity and migration of the human trophoblast HTR-8/SVneo cell in vitro. miR-98 could bind to GDF6 and FAPP2 mRNA 3’-UTR and negatively regulate their expression. The downregulation of miR-98 promoted cell proliferation, then knockdown of GDF6 or FAPP2 inhibited miR-98-mediated cell proliferation. GDF6 and FAPP2 expression in the placental villi from MA patients were decreased compared to normal placental tissues. The expression of miR-98 in MA had an opposite relationship with the expression of GDF6 and FAPP2. Overexpression of miR-98 is associated with the occurrence of MA. miR-98 prevents proliferation, viability and migration of trophoblast cells partially through targeting GDF6 and FAPP2.
Mian Liu, Xia Chen, Qing-Xian Chang, Rui Hua, Yan-Xing Wei, Li-Ping Huang, Yi-xin Liao, Xiao-Jing Yue, Hao-Yue Hu, Fei Sun, Si-Jia Jiang, Song Quan and Yan-Hong Yu
Small extracellular vesicles (sEVs) are important mediators of cell-to-cell communication involved in the successful establishment of a pregnancy. Human decidual stromal cells play a key role in regulating trophoblast invasion. Nevertheless, the regulatory functions of decidual stromal cells-derived sEVs in human trophoblast cells are still unclear. In this study, primary human decidual stromal cells were isolated, and immortalized human endometrial stromal cell line (HESCs) were decidualized into human decidual stromal cells (HDSCs) using hormonal cocktail containing medroxy progesterone 17-acetate (MPA), estrogen and cAMP analog. HDSC-sEVs were isolated from both primary human decidual stromal cells and immortal HDSCs, respectively, and identified by transmission electron microscopy and western blotting. EV uptake assay indicated that HDSC-sEVs could be uptaken by trophoblast cells. HDSC-sEVs could increase the invasiveness and the expression level of N-cadherin of trophoblast cells with elevated phosphorylation of SMAD2 and SMAD3 in the cells. Silencing of N-cadherin could block cell invasion induced by HDSC-sEVs, while knockdown of SMAD2 and SMAD3 could inhibit the upregulation of N-cadherin in trophoblast cells. Taken together, our results suggested a regulatory effect of HDSC-sEVs in the invasion of trophoblast cells, and HDSC-sEVs may be important mediators of trophoblasts during embryo implantation and placentation.