Circulating MicroRNA Profile as a Potential Predictive Biomarker for Early Diagnosis of Spontaneous Abortion in Patients With Subclinical Hypothyroidism

Maternal circulating exosomal miR-185-5p levels as a predictive biomarker in patients with recurrent pregnancy loss

PURPOSE

The aim of this study was to explore the predictive role of microRNAs (miRNAs) from maternal serum exosomes in early recurrent pregnancy loss (RPL) and the related mechanism in early pregnancy.

METHODS

Maternal serum was collected from pregnant women with RPL history or women with ongoing pregnancy (OP); serum exosomes were extracted and identified. Differentially expressed (DE) miRNAs in exosomes were screened by RNA sequencing and further validated by qRT-PCR. Next, the predictive value of exosomal miRNA and the clinical indicators for subsequent miscarriage in RPL patients were evaluated. Additionally, we verified the regulatory relationship between miR-185-5p and vascular endothelial growth factor (VEGF) in decidual natural killer (dNK) cells by overloading or inhibiting the exosomal miR-185-5p level in trophoblast cells.

RESULTS

The miRNA sequencing revealed 43 DE miRNAs between OP and RPL patients. The five most significant DE miRNAs (miR-22-3p, miR-185-5p, miR-335-3p, miR-362-5p, and miR-378a-3p) were selected for identification, and miR-185-5p was increased in RPL patients. The area under curve (AUC) of the receiver operating characteristic was 0.925 when using miR-185-5p as a biomarker for subsequent miscarriage in RPL patients. In addition, miR-185-5p in exosomes secreted from HTR-8 cells reduces VEGF expression of dNK cells.

CONCLUSIONS

The current study, for the first time, successfully constructed the correlation between maternal circulating exosomal miR-185-5p expression pattern and RPL, which may be involved in the pathogenesis of RPL by downregulating the VEGFA of dNK cells and perturbing angiogenesis at the maternal-fetal interface.

Tear miRNA expression analysis reveals miR-203 as a potential regulator of corneal epithelial cells

Background

microRNAs (miRNAs) are small noncoding RNAs that negatively regulate gene expression. They are found within cells and in body fluids. Extracellular miRNAs have been shown to associate with the surrounding tissues. Therefore, we predicted that miRNAs in tears may contribute to regulate corneal epithelial cell function. However, information on the miRNA expression profile of tears is limited and the specific functions of tear miRNAs for corneal epithelial cells are still unknown. To study the role of tear miRNAs, we determined which miRNAs are highly expressed in tears and examined the involvement of miRNAs in corneal epithelial cell viability.

Methods

miRNAs extracted from monkey tears and sera were subjected to microarray analysis. miRNAs of which expression levels were higher in tears than in sera were selected, and their expression levels were quantified by quantitative polymerase chain reaction (qPCR). To examine miRNA function, mimics and inhibitors of miRNAs were transfected into human corneal epithelial (HCE-T) cells and incubated for 24 or 48 h. After transfection of miRNA mimics and inhibitors, the viability of HCE-T cells was measured using the water soluble tetrazolium salt (WST) assay, and microarray analysis and qPCR were performed using total RNA extracted from HCE-T cells. siRNAs of the candidate targets for miR-203 were transfected into HCE-T cells and the WST assay was performed. To determine a direct target gene for miR-203, a dual luciferase reporter assay was performed in HCE-T cells using a luciferase reporter plasmid containing 3′-UTR of human IGFBP5.

Results

Microarray and qPCR analyses showed that miR-184 and miR-203 were expressed significantly more highly in tears than in sera (165,542.8- and 567.8-fold, respectively, p < 0.05). Of these two miRNAs, transfection of a miR-203 mimic significantly reduced the viability of HCE-T cells (p < 0.05), while a miR-203 inhibitor significantly increased this viability (p < 0.05). miR-203 mimic downregulated insulin-like growth factor-binding protein 5 (IGFBP5) and nuclear casein kinase and cyclin-dependent kinase substrate 1 (NUCKS1), while miR-203 inhibitor upregulated these two genes. Transfection of IGFBP5-siRNA decreased the viability of HCE-T cells. miR-203 mimic significantly diminished the luciferase reporter activity.

Conclusions

In this study, we identified miRNAs that are highly expressed in tears, and the inhibition of miR-203 increases the viability of corneal epithelial cells. Our results suggest that miR-203 contributes to regulating the homeostasis of corneal epithelial cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-02141-9.

Differential expression of urine-circulating micro-RNAs in Chlamydia trachomatis-induced recurrent spontaneous aborters

Studies behind mechanisms of Chlamydia trachomatis-induced recurrent spontaneous abortion is still in its infancy. Possible strategy for preventing recurrent spontaneous abortion at molecular level is needed. Despite its multifactorial aetiology, Chlamydia trachomatis is important cause of RSA. However, mechanism leading to RSA in C. trachomatis-positive patients is not understood and novel strategies are needed. It is hypothesized that microRNAs play important role in RSA regulation during infection. Study aimed to elucidate expression/role of urine-circulating miRs-320b, 221-3p, 146b-5p,-16,-24,-559 in recurrent spontaneous aborters with C. trachomatis infection and to find their target genes by bioinformatic analysis. First-void urine was collected from 30 non-pregnant women with RSA (Group I) and 30 non-pregnant women with ≥2 successful deliveries (Group II; Controls) attending Department of Obstetrics and Gynaecology, Vardhman Mahavir Medical College, Safdarjung hospital, New Delhi (India). PCR was performed to detect C. trachomatis. Expression of miRNAs was studied by quantitative real-time PCR while target genes/functional annotations were predicted by GO/KEGG databases. Data was statistically evaluated. 05 RSA patients were C. trachomatis-positive. Group I was subdivided into Group Ia (C. trachomatis-positive RSA; n = 5) and Group Ib (C. trachomatis-negative RSA; internal controls). miR-320b, -221-3p, -146b-5p, -16, -24 were significantly upregulated (miR-16 showed maximum 4.3 fold-change) while miR-559 was downregulated (0.5 fold-change) in Group Ia versus controls ('p'<0.001). Bioinformatic analysis revealed that target genes of miRNAs in RSA are involved in apoptosis and AMPK signalling pathways. Results showed differential expression of miRNAs implyingmiR-16 and miR-559 as potential biomarkers of RSA in infected women. Furthermore, network of genes of differentially expressed miRNAs regulates RSA by targeting gene function in apoptosis, cell adhesion and angiogenesis.

Increased miR-6875-5p inhibits plasmacytoid dendritic cell differentiation via the STAT3/E2-2 pathway in recurrent spontaneous abortion

Recurrent spontaneous abortion (RSA) is a common complication of early pregnancy. Dendritic cells (DCs) are thought to confer fetal–maternal immunotolerance and play a crucial role in ensuring a successful pregnancy. A decrease of plasmacytoid dendritic cells (pDCs) was found to be involved in RSA, but the underlying mechanisms of decreased pDC in RSA remain unclear. MicroRNAs (miRNAs) play critical roles in RSA as well as the development, differentiation and functional regulation of pDCs; however, the regulatory effect of miRNAs on pDC in RSA has not been fully investigated. Here we demonstrated that both the proportion of pDC and signal transducer and activator of transcription (STAT3)/transcription factor 4 (Tcf4/E2-2) expression decreased in the peripheral blood mononuclear cells and decidua of patients with RSA compared to those with normal pregnancy (NP), and there was a significantly positive correlation between pDC and STAT3 mRNA. MiRNA microarray assay and quantitative reverse transcription PCR results showed that miR-6875-5p expression was markedly increased in women with RSA and negatively correlated with mRNA expression level of STAT3. Up-regulated miR-6875-5p could sensitively discriminate patients with RSA from NP subjects. Overexpression of miR-6875-5p significantly down-regulated the mRNA expression of STAT3 and E2-2 as well as the protein and phosphorylation level of STAT3, while miR-6875-5p knockdown showed opposite results. Dual luciferase reporter verified that miR-6875-5p regulated STAT3 expression by directly binding to its 3'untranslated region. Overall, our results suggested that increased miR-6875-5p is involved in RSA by decreasing the differentiation of pDCs via inhibition of the STAT3/E2-2 signaling pathway. miR-6875-5p may be explored as a promising diagnostic marker and therapeutic target for RSA.

Comprehensive analysis of the differential expression profile of microRNAs in missed abortion

To screen the key circulating microRNAs (miRNAs) involved in missed abortion (MA) and explore their role in MA process. We examined the miRNA profile from the serum of three MA patients and three early pregnancy induced abortion patients (controls) by next-generation sequencing. We analyzed the target genes of the differentially expressed (DE) miRNAs to analyze the function and pathway enrichment using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes, respectively. We validated five candidate miRNAs by real time-qPCR. Integrated miRNA-mRNA-pathway network analysis was performed to show the interaction network of the candidate miRNAs and their target genes of interest with the involved pathways. It was observed that 227 miRNAs were differently expressed between the MA group and the early pregnancy control group, with 58 miRNAs downregulated and 169 miRNAs upregulated in the MA group. Real-time qPCR results revealed that expression of the five candidate miRNAs, namely hsa-miR-22-3p, hsa-miR-145-3p, hsa-miR-107, hsa-miR-361-3p, and hsa-miR-378c, was consistent with the miRNA data obtained by sequencing. Integrated miRNA-mRNA-pathway network analysis illustrated that target genes of the candidate miRNAs were mainly involved in the PI3K-Akt signaling pathway, HIF-1 signaling pathway, and VEGF signaling pathway, which would have potential significance in pregnancy and MA. We are the first to reveal the DE miRNAs involved in MA and illustrate their functional interaction network. These results might provide potential circulating biomarkers and new therapeutic targets for MA.

Liquid Biopsy as a Minimally Invasive Source of Thyroid Cancer Genetic and Epigenetic Alterations

In the blood of cancer patients, some nucleic acid fragments and tumor cells can be found that make it possible to trace tumor changes through a simple blood test called “liquid biopsy”. The main components of liquid biopsy are fragments of DNA and RNA shed by tumors into the bloodstream and circulate freely (ctDNAs and ctRNAs). Tumor cells which are shed into the blood (circulating tumor cells or CTCs), and exosomes that have been investigated for non-invasive detection and monitoring several tumors including thyroid cancer. Genetic and epigenetic alterations of a thyroid tumor can be a driver for tumor genesis or essential for tumor progression and invasion. Liquid biopsy can be real-time representative of such genetic and epigenetic alterations to trace tumors. In thyroid tumors, the circulating BRAF mutation is now taken into account for both thyroid cancer diagnosis and determination of the most effective treatment strategy. Several recent studies have indicated the ctDNA methylation pattern of some iodine transporters and DNA methyltransferase as a diagnostic and prognostic biomarker in thyroid cancer as well. There has been a big hope that the recent advances of genome sequencing together with liquid biopsy can be a game changer in oncology.

Altered miRNA profile in testis of post-cryptorchidopexy patients with non-obstructive azoospermia

BACKGROUND

Cryptorchidism is one of the most common causes of non-obstructive azoospermia (NOA) leading to male infertility. Despite various medical approaches been utilised, many patients still suffer from infertility. MicroRNAs (miRNAs) play vital roles in the progress of spermatogenesis; however, little is known about the miRNA expression profile in the testes. Therefore, the miRNA profile was assessed in the testis of post-cryptorchidopexy patients.

METHODS

Three post-cryptorchidopexy testicular tissue samples from patients aged 23, 26 and 28 years old and three testis tissues from patients with obstructive azoospermia (controls) aged 24, 25 and 36 years old were used in this study. Next-generation sequencing (NGS) was used to perform the miRNA expression profiling. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assays were subsequently used to confirm the results of several randomly-selected and annotated miRNAs.

RESULTS

A series of miRNAs were found to be altered between post-cryptorchidopexy testicular tissues and control tissues, including 297 downregulated and 152 upregulated miRNAs. In the subsequent qRT-PCR assays, the expression levels of most of the selected miRNAs (9/12, P < 0.05) were consistent with the results of NGS technology. Furthermore, signal transduction, adaptive immune response and biological regulation were associated with the putative target genes of the differentially-expressed miRNAs via GO analysis. In addition, oxidative phosphorylation, Parkinson's disease and ribosomal pathways were shown to be enriched using KEGG pathway analysis of the differentially-expressed genes.

CONCLUSIONS

This study provides a global view of the miRNAs involved in post-cryptorchidopexy testicular tissues as well as the altered expression of miRNAs compared to control tissues, thus confirming the vital role of miRNAs in cryptorchidism.