The microRNApolymorphisms inmiR-150 and miR-1179 are associated with risk of idiopathic recurrent pregnancy loss

Micro-RNAs in Human Placenta: Tiny Molecules, Immense Power

Micro-RNAs (miRNAs) are short non-coding single-stranded RNAs that modulate the expression of various target genes after transcription. The expression and distribution of kinds of miRNAs have been characterized in human placenta during different gestational stages. The identified miRNAs are recognized as key mediators in the regulation of placental development and in the maintenance of human pregnancy. Aberrant expression of miRNAs is associated with compromised pregnancies in humans, and dysregulation of those miRNAs contributes to the occurrence and development of related diseases during pregnancy, such as pre-eclampsia (PE), fetal growth restriction (FGR), gestational diabetes mellitus (GDM), recurrent miscarriage, preterm birth (PTB) and small-for-gestational-age (SGA). Thus, having a better understanding of the expression and functions of miRNAs in human placenta during pregnancy and thereby developing novel drugs targeting the miRNAs could be a potentially promising method in the prevention and treatment of relevant diseases in future. Here, we summarize the current knowledge of the expression pattern and function regulation of miRNAs in human placental development and related diseases.

Role of miRNA polymorphism in recurrent pregnancy loss: a systematic review and meta-analysis

There are a plethora of publications on the role of miRNA gene polymorphism and its association with recurrent pregnancy loss (RPL), but a lack of uniformity in the studies available due to the variable subject population, heterogeneity and contrary results of significance. Rigorous data mining was done through PubMed, SCOPUS, Cochrane library, Elsevier and Google Scholar to extract the studies of interest published until June 2021. A total of eight SNPs of miRNAs have been included, where ≥2 studies per SNPs were available. Analysis was done on the basis of pooled odds ratios and 95% CI. This is the first meta-analysis on miRNA SNPs in RPL that suggests that rs11614913, rs3746444 and rs2292832 biomarkers may decrease the risk of RPL under different genetic models.

MicroRNA signatures in plasma and plasma exosome during window of implantation for implantation failure following in-vitro fertilization and embryo transfer

BACKGROUND

MicroRNAs (miRNAs) are small, non-coding RNAs that are dysregulated in many diseases and can act as biomarkers. Although well-studied in cancer, the role of miRNAs in embryo implantation is poorly understood. Approximately 70% of embryos fail to implant following in-vitro fertilization and embryo transfer, 10% of patients experienced recurrent implantation failure. However, there are no well-established biomarkers that can predict implantation failure. Our purpose is to investigate distinct miRNA profiles in plasma and plasma exosomes during the window of implantation between patients with failed implantation and successful implantation.

METHODS

We select a nested case-control population of 12 patients with implantation failure or successfully clinical pregnancy using propensity score matching. RNA was extracted from plasma and plasma exosomes collected during the window of implantation (WOI). MicroRNA expression in all samples was quantified using microRNA sequencing. The intersection of differently expressed miRNAs in plasma and exosomes were further validated in the GEO dataset. Significantly altered microRNAs in both plasma and plasma exosomes were then subjected to target prediction and KEGG pathway enrichment analyses to search for key signaling pathways. WGCNA analysis was performed to identify hub miRNAs associated with implantation.

RESULTS

13 miRNAs were differentially expressed in both plasma and plasma exosomes in patients with implantation failure. Among them, miR-150-5p, miR-150-3p, miR-149-5p, and miR-146b-3p had consistent direction changes in endometrium of patients with recurrent implantation failure (RIF), miR-342-3p had consistent direction changes in blood samples of patients with RIF. Pathway enrichment analysis showed that the target genes of differentially expressed miRNAs are enriched in pathways related to embryo implantation. WGCNA analysis indicated that miR-150-5p, miR-150-3p, miR-146b-3p, and miR-342-3p are hub miRNAs.

CONCLUSIONS

Implantation failure is associated with distinct miRNA profiles in plasma and plasma exosomes during WOI.

Bone Marrow Mesenchymal Stem Cells (BMSCs)-Derived miR-31 in the Pathogenesis of Recurrent Abortion by Regulating Kisspeptins 1 (KISS1) Expression

Bone marrow mesenchymal stem cells (BMSCs) are potentially efficacious in treating recurrent pregnancy disorders and endometrial injury. Uterine parenchymal cells interact with BMSCs to promote functional recovery. Our research aimed to explore the effect of BMSCs-derived miR-31 on recurrent pregnancy loss. A recurrent pregnancy loss mouse model was constructed followed by nanoparticle analysis of BMSC and miR-31 expressing by RT-PCR. The levels of miR-31 in BMSCs (miR-31+BMSCs or BMSCs) and their counterpart exosomes were up- or down-regulated to explore the effects of aberrant expression of miR-31 on endometrial damage in recurrent pregnancy loss. The analysis of BMSC nanoparticles showed that miR-31 was derived from BMSC. We found increased levels of miR-31 in miR-340 + BMSCs after incubation with endometrial stromal cells (ESCs) compared to controls. Labeling of exosomes by red fluorescent protein indicated that exosomes were liberated out of BMSCs and translocated into neighboring ESCs, and mice treated with miR-340 + BMSCs had improved functional recovery from recurrent pregnancy loss. BMSC-derived miR-31 mediates functional recovery induced in recurrent pregnancy miscarriage mice by regulating KISS1 expression and fibrosis gene expression.

Association between HOX Transcript Antisense RNA Single-Nucleotide Variants and Recurrent Implantation Failure

Recurrent implantation failure (RIF) refers to the occurrence of more than two failed in vitro fertilization–embryo transfers (IVF-ETs) in the same individual. RIF can occur for many reasons, including embryo characteristics, immunological factors, and coagulation factors. Genetics can also contribute to RIF, with some single-nucleotide variants (SNVs) reported to be associated with RIF occurrence. We examined SNVs in a long non-coding RNA, homeobox (HOX) transcript antisense RNA (HOTAIR), which is known to affect cancer development. HOTAIR regulates epigenetic outcomes through histone modifications and chromatin remodeling. We recruited 155 female RIF patients and 330 healthy controls, and genotyped HOTAIR SNVs, including rs4759314, rs920778, rs7958904, and rs1899663, in all participants. Differences in these SNVs were compared between the patient and control groups. We identified significant differences in the occurrence of heterozygous genotypes and the dominant expression model for the rs1899663 and rs7958904 SNVs between RIF patients and control subjects. These HOTAIR variants were associated with serum hemoglobin (Hgb), luteinizing hormone (LH), total cholesterol (T. chol), and blood urea nitrogen (BUN) levels, as assessed by analysis of variance (ANOVA). We analyzed the four HOTAIR SNVs and found significant differences in haplotype patterns between RIF patients and healthy controls. The results of this study showed that HOTAIR is not only associated with the development of cancer but also with pregnancy-associated diseases. This study represents the first report showing that HOTAIR is correlated with RIF.

Long noncoding RNA MALAT1 contributes to pregnancy-induced hypertension development by enhancing oxidative stress and inflammation through the regulation of the miR-150-5p/ET-1 axis

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified previously in the pathogenesis of hypertension and some gestational diseases. However, the biological functions of MALAT1 in pregnancy-induced hypertension (PIH) are still poorly understood. Herein, we aim to explore the functional relevance of MALAT1 in PIH and to explain the potential underlying mechanisms. We found that the levels of ET-1 and MALAT1 were upregulated and that of miR-150-5p were downregulated in the serum of pregnant women with PIH and the aortic endothelial cells (ECs) of reduced uterine perfusion pressure (RUPP)-induced rat models. In aortic ECs, MALAT1 could competitively bind to miR-150-5p to upregulate the expression of ET-1. The MALAT1/miR-150-5p/ET-1 axis regulated the expression of endothelin B receptor (ETBR) in aortic ECs leading to oxidative stress imbalance and increased the release of proinflammatory cytokines (IL-18 and IL-1β), which concurrently activated the NF-κB pathway to regulate the ETBR expression and to stimulate smooth muscle cell (SMC) contraction. Furthermore, silencing MALAT1 could alleviate the hypertensive symptoms of RUPP-induced rat models. Taken conjointly, the upregulation of MALAT1 can reduce the expression of ET-1 by competitively binding to miR-150-5p, which enhances the expression of ETBR via the activation of the NF-κB pathway in SMCs, thus exacerbating the hypertensive symptoms in the RUPP-induced rat models.

Study of the Association Between microRNA (miR-25T>C, miR-32C>A, miR-125C>T, and miR-222G>T) Polymorphisms and the Risk of Recurrent Pregnancy Loss in Korean Women

Recurrent pregnancy loss (RPL), which is defined as two pregnancy losses that occur before 20 weeks of gestation, is relatively common, occurring in approximately 1–5% of women. The underlying cause is often unclear, although numerous factors may contribute to RPL, including environmental and immunological factors, blood coagulation disorders, and genetics. In particular, single nucleotide variants have been associated with RPL, including those found in microRNAs (miRNAs). We investigated the association between four miRNA polymorphisms, miR-25T>C, miR-32C>A, miR-125aC>T, and miR-222G>T, and RPL in a cohort consisting of 361 RPL patients and 272 controls. Subjects were genotyped at miRNA loci by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, and genotype frequencies were calculated. We then performed allele and genotype combination analyses and measured the association between miRNA polymorphisms and clinical variables in both RPL patients and controls. We detected a statistically significant association between RPL and the miR-25T/miR-32C/miR-125aT/miR-222T allele combination (adjusted odds ratio (AOR), 4.361; 95% confidence interval (CI), 1.496–12.72; P = 0.003). Three-gene combinations, including miR-32C/miR-125aT/miR-222T (AOR, 3.085; 95% CI, 1.254–7.588; P = 0.010) and miR-25T/miR-125aT/miR-222T (AOR, 2.929; 95% CI, 1.183–7.257; P = 0.015), and the two-gene combination miR-125aT/miR-222T (AOR, 2.417; 95% CI, 1.084–5.386; P = 0.026) were also associated with RPL. Analysis of variance (ANOVA) revealed that platelet counts and blood urea nitrogen levels were significantly different in RPL patients expressing different miR-125aC>T and miR-25T>C genotypes, respectively (P < 0.05). In addition, creatinine levels were lower in RPL patients expressing the minor alleles miR-25T>C and miR-32C>A. We investigated miRNAs (miR-25, miR-32, miR-125a, miR-222) in RPL patients and healthy controls. Significantly different allele frequencies were detected by ANOVA. We suggest that miRNAs and clinical factors can impact RPL occurrence.

Association study of AGO1 and AGO2 genes polymorphisms with recurrent pregnancy loss

An Argonaute (AGO) protein within the RNA-induced silencing complex binds a microRNA, permitting the target mRNA to be silenced. We hypothesized that variations in AGO genes had the possibility including affected the miRNA function and associated with recurrent pregnancy loss (RPL) susceptibility. Especially, we were chosen the AGO1 (rs595961, rs636832) and AGO2 (rs2292779, rs4961280) polymorphisms because of those polymorphisms have already reported in other diseases excluding the RPL. Here, we conducted a case-control study (385 RPL patients and 246 controls) to evaluate the association of four polymorphisms with RPL. We found that the AGO1 rs595961 AA genotype, recessive model (P = 0.039; P = 0.043, respectively), the AGO1 rs636832 GG genotype, and recessive model (P = 0.037; P = 0.016, respectively) were associated with RPL in women who had had four or more consecutive pregnancy losses. The patients with the AGO1 rs636832 GG genotypes had greater platelet counts (P = 0.023), while the patients with the AGO2 rs4961280 CA genotypes had less homocysteine (P = 0.027). Based on these results, we propose that genetic variations with respect to the AGO1 and AGO2 genotypes are associated with risk for RPL, and might serve as useful biomarkers for the prognosis of RPL.