Associations of single nucleotide polymorphisms in precursor-microRNA (miR)-125a and the expression of mature miR-125a with the development and prognosis of autoimmune thyroid diseases

Helper T Cell 17 and Regulatory T Cell Levels in Peripheral Blood of Newly Diagnosed Patients with Autoimmune Thyroid Disease: A Meta-Analysis

This article aims to explore associated immune indicators of autoimmune thyroid disease (AITD) through a meta-analysis of published case-control studies on newly diagnosed AITD patients, intending to provide some suggestions for research on the mechanisms of AITD. Six electronic databases were searched for case-control studies on newly diagnosed AITD patients from inception to August 15, 2022. A random-effects model was used to calculate the standardized mean difference (SMD), odds ratio (OR), and 95% confidence interval (95% CI). A total of 26 articles were included in this meta-analysis. Patients with newly diagnosed AITD had higher levels of helper T cell 17 (Th17) (Hashimoto's disease (HT): SMD=2.35, 95% CI: 1.98, 2.72; Graves' disease (GD): SMD=1.61, 95% CI: 1.23, 1.98), lower levels of regulatory T cell (Treg) (HT: SMD=-2.04, 95% CI: -2.67, -1.42; GD: SMD=-1.35, 95% CI: -2.11, -0.58), and lower levels of forkhead box P3 (FoxP3) mRNA (HT: SMD=-2.58, 95% CI: -3.12, -2.05; GD: SMD=-2.13, 95% CI: -2.56, -1.70), compared to the healthy population. In addition, the single nucleotide polymorphism rs3761548 and rs3761549 in the promoter region of FoxP3 showed a higher frequency in the comparison of genotype "CT" only in HT patients than in the healthy population (OR=1.66, 95%CI: 1.18, 2.34). In patients with newly diagnosed AITD, the Th17/Treg ratio imbalance may develop AITD. Monitoring Th17 and Treg levels may become an essential tool to assess the organism's immune homeostasis and hopefully guide clinical diagnosis and treatment.

Implications of Decreased Expression of miR-125a with Respect to Its Variant Allele in the Pathogenesis of Recurrent Pregnancy Loss: A Study in a High Incidence Zone

Pregnancy is controlled by several types of genes and the regulation of their expression is tightly controlled by miRNAs. The present study was carried out to explore the association between miR-125a polymorphic sequence variation and its expression and recurrent pregnancy loss (RPL) compared to full-term healthy controls. A total of 150 women that had experienced two or more RPLs and 180 healthy controls (two or more full-term pregnancies) were recruited, along with 50 product of conception (POC) samples from the corresponding RPL patients, and evaluated for miR-125a SNPs by the polymerase chain reaction-restriction fragment length polymorphism method (PCR-RFLP), which was confirmed by high resolution melting (HRM)/DNA sequencing. Additionally, the expression of miR-125a was quantified with q−PCR in the maternal plasma of 40 corresponding RPL patients against healthy controls. The frequency of variant genotype CC was significantly higher in RPL cases (19.3%) than controls (10.5%), with an odds ratio of >2 (p = 0.025). The expression levels of miR-125a were markedly decreased in RPL cases compared to healthy controls (p < 0.05). Variant genotype CC was found significantly more often in RPL cases than controls (0.34 vs. 0.20; p < 0.05).In this study, miR-125a rs12976445 C/T revealed that the homozygous CC genotype and C allele were associated with the risk of RPL and significant expression indicates that miR-125a has an important role in RPL etiopathogenesis.

Meta-Analysis of miRNA Variants Associated with Susceptibility to Autoimmune Disease

Purpose

Various studies have shown an association between miRNA polymorphisms and susceptibility to autoimmune disease (AD); however, the results are inconclusive. To evaluate whether miRNA polymorphisms account for a significant risk of AD, a total of 87 articles, including 39431 patients and 56708 controls, were identified to estimate their association with 12 AD subtypes.

Methods

Several electronic databases were searched to analyze population-based studies on the relationship between miRNA variants and AD risk. Fixed effects or random effect models were used in the meta-analysis for the risk assessment.

Results

In our meta-analysis, miR-146a rs2910164/rs57095329 conferred a marginally elevated risk for AD (allele model, OR = 1.08, 95% CI: 1.01-1.15, P = 0.019; allele model, OR = 1.09, 95 CI: 1.05-1.15, P < 0.001, respectively). Furthermore, miR-196a2 rs11614913 was also associated with AD risk (allele model, OR = 0.92, 95% CI: 0.88-0.97, P = 0.001) as well as miR-499 rs3746444 (allele model, OR = 1.16, 95% CI: 1.03-1.29, P = 0.011). In addition, associations were observed between miR-149 rs2292832/miR-27a rs895819 and AD susceptibility in the overall population (allele model, OR = 1.15, 95% CI: 1.06-1.24, P < 0.001; allele model, OR = 1.11, 95% CI:1.01-1.22, P = 0.043, respectively).

Conclusions

Evidence from our systematic review suggests that miR-146a, miR-196a2, miR-499, miR-149, and miR-27a polymorphisms are associated with susceptibility to AD.

Spontaneous and Immune Checkpoint Inhibitor-Induced Autoimmune Diseases: Analysis of Temporal Information by Using the Japanese Adverse Drug Event Report Database

BACKGROUND AND OBJECTIVE

Immune checkpoint inhibitors (ICIs) such as programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) inhibitors have greatly improved cancer treatment. However, they are associated with immune-related adverse events, including autoimmune diseases (ADs) owing to their immune enhancement effect. As there are few comprehensive studies of ADs by ICIs, it is necessary to analyze the period information of drug-induced ADs. We also assumed that the temporal information may be useful to estimate the similarity of the pathogenic mechanism between spontaneous and ICI-induced ADs.

METHODS

A period analysis including the Weibull analysis was performed on ICI-induced ADs using the Japanese Adverse Drug Event Report (JADER) database. For evaluating the similarity of spontaneous and ICI-induced ADs, a hierarchical cluster analysis was conducted to compare the different onset-time ranges.

RESULTS

Type 1 diabetes mellitus, autoimmune colitis, and pemphigoid occurred earlier with CTLA-4 inhibitors (median: 46, 29.5 and 28 days, respectively) than with PD-1 inhibitors (> 130 days). Myasthenia gravis had a median time to onset of approximately 1 month, and the risk of onset would increase over time in ipilimumab combination therapy. This result reveals ADs that require attention. Using cluster analysis, we estimated six clusters with different patterns of onset times. Based on these results and a detailed previous research survey, the possible pathogenesis of drug-induced ADs was also discussed.

CONCLUSIONS

This paper describes risk profiles with temporal information of ICI-induced ADs and proposes certain indicators for deciphering the mechanism of AD onset.

In silico Analysis of Polymorphisms in microRNAs Deregulated in Alzheimer Disease

BACKGROUND

Alzheimer's disease (AD) is a degenerative condition characterized by progressive cognitive impairment and dementia. Findings have revolutionized current knowledge of miRNA in the neurological conditions. Two regulatory mechanisms determine the level of mature miRNA expression; one is miRNA precursor processing, and the other is gene expression regulation by transcription factors. This study is allocated to the in-silico investigation of miRNA's SNPs and their effect on other cell mechanisms.

METHODS

We used databases which annotate the functional effect of SNPs on mRNA-miRNA and miRNA-RBP interaction. Also, we investigated SNPs which are located on the promoter or UTR region.

RESULTS

miRNA SNP3.0 database indicated several SNPs in miR-339 and miR-34a in the upstream and downstream of pre-miRNA and mature miRNAs. While, for some miRNAs miR-124, and miR-125, no polymorphism was observed, and also miR-101 with ΔG -3.1 and mir-328 with ΔG 5.8 had the highest and lowest potencies to produce mature microRNA. SNP2TFBS web-server presented several SNPs which altered the Transcription Factor Binding Sites (TFBS) or generated novel TFBS in the promoter regions of related miRNA. At last, RBP-Var database provided a list of SNPs which alter miRNA-RBP interaction pattern and can also influence other miRNAs' expression.

DISCUSSION

The results indicated that SNPs microRNA affects both miRNA function and miRNA expression. Our study expands molecular insight into how SNPs in different parts of miRNA, including the regulatory (promoter), the precursor (pre-miRNA), functional regions (seed region of mature miRNA), and RBP-binding motifs, which theoretically may be correlated to the Alzheimer's disease.

Decreased Treg Cell and TCR Expansion Are Involved in Long-Lasting Graves' Disease

Graves' disease (GD) is a T cell-mediated organ-specific autoimmune disorder. GD patients who have taken anti-thyroid drugs (ATDs) for more than 5 years with positive anti-thyroid stimulating hormone receptor autoantibodies value were defined as persistent GD (pGD). To develop novel immunotherapies for pGD, we investigated the role of T cells in the long-lasting phase of GD. Clinical characteristics were compared between the pGD and newly diagnosed GD (nGD) (N = 20 respectively). Flow cytometric analysis was utilized to determine the proportions of Treg and Th17 cells (pGD, N = 12; nGD, N = 14). T cell receptor sequencing (TCR-seq) and RNA sequencing (RNA-seq) were also performed (pGD, N = 13; nGD, N = 20). Flow cytometric analysis identified lower proportions of Th17 and Treg cells in pGD than in nGD (P = 0.0306 and P = 0.0223). TCR-seq analysis revealed a lower diversity (P = 0.0025) in pGD. Specifically, marked clonal expansion, represented by an increased percentage of top V-J recombination, was observed in pGD patients. Interestingly, pGD patients showed more public T cell clonotypes than nGD patients (2,741 versus 966). Meanwhile, RNA-seq analysis revealed upregulation of the inflammation and chemotaxis pathways in pGD. Specifically, the expression of pro-inflammatory and chemotactic genes (IL1B, IL13, IL8, and CCL4) was increased in pGD, whereas Th17 and Treg cells associated genes (RORC, CARD9, STAT5A, and SATB1) decreased in pGD. Additionally, TCR diversity was negatively correlated with the expression of pro-inflammatory or chemotactic genes (FASLG, IL18R1, CCL24, and CCL14). These results indicated that Treg dysregulation and the expansion of pathogenic T cell clones might be involved in the long-lasting phase of GD via upregulating chemotaxis or inflammation response. To improve the treatment of pGD patients, ATDs combined therapies, especially those aimed at improving Treg cell frequencies or targeting specific expanded pathogenic TCR clones, are worth exploring in the future.

Dysregulation of non-coding RNAs in autoimmune thyroid disease

Autoimmune thyroid disease (AITD) is a complex disorder with both genetic and environmental risk factors. A number of genetic factors such as HLA and CTLA-4 loci have been associated with risk of this disorder. In addition to these factors, recent studies have shown contribution of non-coding RNAs in the pathogenesis of this condition. Several microRNAs (miRNAs) and a number of long noncoding RNAs (lncRNAs) such as IFNG-AS1, Heg, NR_038461, NR_038462, T204821 and NR_104125 have been dysregulated in peripheral blood of patients with AITD. These transcripts are mostly enriched in pathways that modulate humoral and cellular immune responses such as those associated with antigen presentation and differentiation of Th1, Th2 and Th17 cells. Functional studies verified the role of a number of lncRNAs and miRNAs in regulation of critical immune-related pathways in AITD. Thus, they participate in the pathophysiology of AITD. In the current review, we summarize the results of studies that assessed participation of non-coding RNAs in the pathophysiology of AITD.

Rs531564 polymorphism in microRNA-214 regulates interleukin-6R expression in anal fissure patients to affect the risk of anal abscess formation

BACKGROUND

Anal abscess is an important complication of anal fissure (AF), whereas interleukin-6R (IL-6R) has been implicated in the development of abscess. In this study, we aimed to explore the possible molecular mechanisms underlying the regulatory effects of miRNAs on IL-6R and other inflammatory factors related to the induction of anal abscess in AF.

METHODS

Bioinformatics analysis, luciferase assay, real-time polymerase chain reaction, and Western blot analysis were performed to identify the possible regulatory relationships between IL-6R and miR-124/miR-125a by comparing the differentiated expression of miR-125a, miR-124, tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), and IL-4 among different groups of AF patients.

RESULTS

IL-6R messenger RNA (mRNA) was identified as a target gene of miR-124 because the luciferase activity in cells cotransfected with wild-type IL-6R and miR-124 mimics was significantly reduced. In addition, the expression of IL-6R mRNA and protein was significantly inhibited in the presence of miR-124 or an IL-6R inhibitor, confirming the presence of a negative regulatory relationship between miR-124 and IL-6R. Moreover, miR-124 and inflammatory factors were differentially expressed in AF patients carrying different genotypes of rs531564 polymorphism.

CONCLUSIONS

miR-124 and inflammatory factors TNF-α, IFN-γ, and IL-4 may be used as indicators of anal abscess development in AF patients. In addition, miR-124 polymorphism rs531564 is involved with the pathogenesis of anal abscess in AF patients, and the presence of rs531564 may increase the incidence of anal abscess via upregulating the expression of IL-6R, TNF-α, IFN-γ, and IL-4.

Rs12976445 Polymorphism Is Associated with Post-Ablation Recurrence of Atrial Fibrillation by Modulating the Expression of MicroRNA-125a and Interleukin-6R

BACKGROUND This study aimed to identify the relationship between miR-125a polymorphism rs12976445 and the post-ablation recurrence of atrial fibrillation (AF), as well as to explore the underlying mechanism of miR-125a in AF recurrence. MATERIAL AND METHODS Microarray analysis was performed to search for miRNAs potentially involved in the regulation of AF recurrence, while real-time PCR (polymerase chain reaction) and Western blot analyses were carried out to study the expression of miR-125a (microRNA-125a), IL-6R (interleukin-6 receptor), and IL-16 (interleukin-16) in different experimental groups, so as to understand the regulatory relationships among miR-125a, IL-6R, and IL-16. Subsequently, a logistic regression analysis was utilized to investigate the survival status of recurrent AF in subjects harboring different genotypes of rs12976445. RESULTS The subjects in the GG and GC/CC groups of miR-125a polymorphism rs12976445 showed no obvious difference regarding all demographic characteristics that were collected in this study. In addition, 19 miRNAs were identified as potentially involved in the regulation of AF recurrence. Among these miRNAs, 6 were upregulated and 13 were downregulated in the group with early recurrence. According to real-time PCR results, the expression of miR-125a was dramatically upregulated in LRAF (late recurrence of atrial fibrillation) as well as in subjects harboring the GG genotype. On the contrary, the level of IL-6R mRNA was dramatically downregulated in LRAF and subjects harboring the GG genotype. Furthermore, IL-6R was confirmed as a candidate target of miR-125a by a luciferase reporter assay. CONCLUSIONS MicroRNA-125a polymorphism rs12976445 plays a role in AF recurrence via the regulation of IL-6R.

Polymorphisms in miRNA genes and their involvement in autoimmune diseases susceptibility

MicroRNAs (miRNAs) are small non-coding RNA molecules that negatively regulate the expression of multiple protein-encoding genes at the post-transcriptional level. MicroRNAs are involved in different pathways, such as cellular proliferation and differentiation, signal transduction and inflammation, and play crucial roles in the development of several diseases, such as cancer, diabetes, and cardiovascular diseases. They have recently been recognized to play a role also in the pathogenesis of autoimmune diseases. Although the majority of studies are focused on miRNA expression profiles investigation, a growing number of studies have been investigating the role of polymorphisms in miRNA genes in the autoimmune diseases development. Indeed, polymorphisms affecting the miRNA genes can modify the set of targets they regulate or the maturation efficiency. This review is aimed to give an overview about the available studies that have investigated the association of miRNA gene polymorphisms with the susceptibility to various autoimmune diseases and to their clinical phenotypes.

Polymorphisms and expression of genes encoding Argonautes 1 and 2 in autoimmune thyroid diseases

The microRNA (miRNA) biogenesis pathway is regulated by specific proteins and enzymes, including Dicer, Drosha, DGCR8, Exportin 5 and the Argonaute (AGO) family. In this study, we investigated the AGO family, which is the primary component of RISC (RNA-induced silencing complex) and directly binds to microRNA. We examined the association of polymorphisms in AGO family genes with AGO expression and with the development and prognosis of autoimmune thyroid diseases. We genotyped AGO1 rs636832A/G, AGO2 rs7005286C/T, AGO2 rs11166985A/G and AGO2 rs2292779C/G polymorphisms in 184 Graves' disease (GD) patients, 195 Hashimoto's disease (HD) patients and 122 healthy volunteers using the polymerase chain reaction-restriction fragment length polymorphism method. We also examined the expression of AGO1 and AGO2 mRNAs in peripheral blood mononuclear cells (PBMC) obtained from 52 GD patients, 41 HD patients, and 25 healthy volunteers using quantitative RT-PCR methods. The G allele of AGO1 rs636832 and the A allele of AGO2 rs11166985 polymorphisms were significantly more frequent in GD patients than in healthy controls. The A allele of AGO2 rs11166985 was also significantly more frequent in intractable GD patients than in controls. The C carrier (CC + CG genotypes) and C allele of AGO2 rs2292779 polymorphism were significantly more frequent in intractable GD patients than in patients with GD in remission. Expression of AGO1 mRNA in PBMC was significantly higher in AITD patient than in controls, and that of AGO2 mRNA in PBMC was significantly higher in intractable GD patients than in patients with GD in remission. Furthermore, the expression levels of both the AGO1 and AGO2 genes were significantly correlated with the proportions of Th17 cells in PBMC. In conclusion, the polymorphisms of the AGO1 and AGO2 genes, the expression levels of which correlated with the proportion of Th17 cells, were associated with the development and prognosis of GD. The AGO2 rs2292779 C carrier and C allele were associated with the intractability of GD.

Association of IL-10-Regulating MicroRNAs in Peripheral Blood Mononuclear Cells with the Pathogenesis of Autoimmune Thyroid Disease

Interleukin (IL)-10 is known to suppress inflammation in autoimmune diseases. IL-10 can be regulated by miRNAs. To elucidate the involvement of miRNAs that regulate IL-10 expression with the pathogenesis of autoimmune thyroid disease (AITD), we examined the expression levels of hsa-miR-27a-3p, hsa-miR-98-5p, hsa-miR-106a-5p, and hsa-miR-223-3p in peripheral blood mononuclear cells (PBMCs) from 43 patients with Graves' disease (GD), 38 patients with Hashimoto's disease (HD), and 21 healthy volunteers. We evaluated the association between the expression levels of four miRNAs and intracellular expression of IL-10 in PBMCs from 11 healthy volunteers. We also genotyped MIR27A rs895819 G/A and MIR106A rs3747440 C/G polymorphisms, which may be related to the expression of these miRNAs in 141 patients with GD, 178 patients with HD, and 84 healthy volunteers. The expression level of hsa-miR-106a-5p was significantly higher in patients with intractable GD than in those with GD in remission (p = 0.0113). The expression level of hsa-miR-223-3p was significantly lower in GD than in HD and lower in patients with intractable GD than in healthy volunteers (p = 0.0094, 0.0340). We found a negative correlation between the expression levels of hsa-miR-98-5p and the proportions of IL-10⁺ cells in stimulated PBMCs from healthy volunteers (p = 0.0092). The G allele of the MIR27A polymorphism was significantly more frequent in patients with mild HD than in healthy volunteers (p = 0.0432). In conclusion, the expression levels of hsa-miR-106a-5p and hsa-miR-223-3p were associated with the pathogenesis of AITDs. hsa-miR-98-5p may negatively regulate the expression of IL-10. The functional polymorphism of MIR27A was associated with HD severity.

The Emerging Role of Epigenetics in Autoimmune Thyroid Diseases

Autoimmune thyroid diseases (AITD) are a group of both B cell- and T cell-mediated organ-specific autoimmune diseases. Graves’ disease and Hashimoto thyroiditis are the two main clinical presentations of AITD. Both genetic and environmental factors have important roles in the development of AITD. Epigenetics have been considered to exert key roles in integrating those genetic and environmental factors, and epigenetic modifications caused by environmental factors may drive genetically susceptibility individuals to develop AITD. Recent studies on the epigenetics of AITD have provided some novel insights into the pathogenesis of AITD. The aim of this review is to provide an overview of recent advances in the epigenetic mechanisms of AITD, such as DNA methylation, histone modifications, and non-coding RNAs. This review highlights the key roles of epigenetics in the pathogenesis of AITD and potential clinical utility. However, the epigenetic roles in AITD are still not fully elucidated, and more researches are needed to provide further deeper insights into the roles of epigenetics in AITD and to uncover new therapeutic targets. Although there are many studies assessing the epigenetic modifications in AITD patients, the clinical utility of epigenetics in AITD remains poorly defined. More studies are needed to identify the underlying epigenetic modifications that can contribute to accurate diagnosis of AITD, adequate choice of treatment approach, and precise prediction of treatment outcomes.

Autoimmune thyroid diseases in children

Autoimmune thyroid diseases (AIT) are common in children and may present with a variety of signs and symptoms including: euthyroid goiter, hypothyroidism, or hyperthyroidism. The natural history of AIT may be different in children but in all age groups, there appear to be genetic risk factors and environmental triggers that initiate thyroid autoimmunity. Areas covered: In this review, we summarize recent studies that investigate the genetics and environmental triggers believed to be involved in thyroid autoimmunity. We also discuss the approach and controversies in the treatment of children with AIT. Expert commentary: Much has been learned about the major roles for genetics, cytokines, regulatory lymphocytes, and environmental triggers in CLT but controversies remain.

Polymorphisms in MIR499A and MIR125A gene are associated with autoimmune thyroid diseases

BACKGROUND

Single nucleotide polymorphisms (SNPs) of the miR-146a, miR-499a and miR-125a have been shown to be associated with the susceptibility to several autoimmune diseases. This study was conducted to identify the association of SNPs rs2910164, rs57095329, rs3746444 and rs12976445 with autoimmune thyroid diseases (AITDs) in a Chinese Han population.

METHODS

We enrolled 1061 patients with AITDs, including 701 patients with Graves' disease (GD) and 360 patients with Hashimoto's thyroiditis (HT), and 938 healthy individuals for a case-control genetic association study. Four SNPs were selected for genotyping by multiplex polymerase chain reaction and ligase detection reaction.

RESULTS

The frequencies of rs3746444 genotypes in patients with AITD and GD differed significantly from those in the controls. The frequencies of rs12976445 genotypes in patients with HT differed significantly from those in the controls. The frequencies of allele C in HT groups were significantly higher than those in control group. For the rs3746444 polymorphism, genetic associations between the combinational genotype and AITD/GD risk were observed in the dominant model, recessive model, and overdominant model. For the rs12976445 polymorphism, genetic associations between the combinational genotype and HT risk were also found in the dominant model and overdominant model. Moreover, gene-sex interactions were identified by GMDR and 2 × 2 crossover analysis.

CONCLUSIONS

Our results suggest rs3746444 (miR-499a) and rs12976445 (miR-125a) associated with AITD susceptibility and potential gene-sex interactions between the four polymorphisms and AITD.

Epigenetics and Autoimmune Thyroid Diseases

Increasing evidence suggests that epigenetic modifications, including changes in DNA methylation, covalent modifications of histone tails, and gene silencing mediated by non-coding RNA molecules, play a substantial role in the pathogenesis of autoimmune disorders and might be seen as the result of environmental insults that trigger these conditions. Studies in cells and tissues of patients with autoimmune thyroid diseases (AITD), and particularly in Graves' disease (GD) and Hashimoto's thyroiditis (HT), are increasingly revealing altered epigenetic marks and resultant deregulation of gene expression levels, but the available data are still limited to be translated into the clinical settings. Particularly, genome-wide methylation and histone tail modification screenings are limited to a few studies in GD patients, and the diagnostic values of the observed epigenetic changes or their potential prognostic utility are still unclear. Similarly, data concerning microRNA expression in AITD patients are largely descriptive and not yet translated into the clinics. In addition, studies relating certain environmental exposures to specific epigenetic changes in AITD and studies evaluating the crosstalk between different epigenetic mechanisms are largely missing. In summary, despite that there is a clear evidence of epigenetic impairment in AITD, further research is required for a better understanding of the epigenetic networks involved in disease pathogenesis, thereby opening the way for potential diagnostic and prognostic tools, as well as for epigenetic interventions in the patients.

Intraindividual variation of microRNA expression levels in plasma and peripheral blood mononuclear cells and the associations of these levels with the pathogenesis of autoimmune thyroid diseases

Background:

microRNAs (miRNAs) circulate in the blood and negatively regulate the expression of mRNAs. Some miRNAs are associated with the development of autoimmune thyroid diseases (AITD); however, there are few reports on the association between miRNA expression and the pathogenesis of AITD or the physiological variations of circulating miRNAs, which are important to examine as biomarkers.

Methods:

We examined the circadian and day-to-day variations in the expression levels of 5 miRNAs (miR-125a, miR-146a, miR-155, let-7e and miR-106a) in plasma and peripheral blood mononuclear cells (PBMC). We also analysed the expression levels of two of these miRNAs (miR-146a and miR-155) in 20 healthy controls, 60 Graves’ disease (GD) patients and 50 Hashimoto’s disease (HD) patients.

Results:

For each miRNA, we observed wide intraindividual variation [coefficient of variation value (CV): 70%–100%] compared to measurement error (CV: 20%–40%). In patients with AITD, HD, GD in remission and mild HD, the expression levels of miR-146a in PBMC were increased 296%, 328%, 348% and 464% above the levels in healthy controls, respectively (p=0.0443 and p=0.0273, p=0.0267 and p=0.0052, respectively). In severe HD, the expression level of miR-155 in plasma was increased to 347% of that in healthy controls (p=0.0256).

Conclusions:

The expression levels of miRNAs in plasma and PBMC showed wide intraindividual variation. In addition, miR-146a may be associated with the development of AITD.

MicroRNA-142-5p contributes to Hashimoto's thyroiditis by targeting CLDN1

Background

MicroRNAs have the potential as diagnostic biomarkers and therapeutic targets in autoimmune diseases. However, very limited studies have evaluated the expression of microRNA profile in thyroid gland related to Hashimoto’s thyroiditis (HT).

Methods

MicroRNA microarray expression profiling was performed and validated by quantitative RT-PCR. The expression pattern of miR-142-5p was detected using locked nucleic acid-in situ hybridization. The target gene was predicted and validated using miRNA targets prediction database, gene expression analysis, quantitative RT-PCR, western blot, and luciferase assay. The potential mechanisms of miR-142-5p were studied using immunohistochemistry, immunofluorescence, and quantitative assay of thyrocyte permeability.

Results

Thirty-nine microRNAs were differentially expressed in HT (Fold change ≥2, P < 0.05) and miR-142-5p, miR-142-3p, and miR-146a were only high expression in HT thyroid gland (P < 0.001). miR-142-5p, which was expressed at high levels in injured follicular epithelial cells, was also detected in HT patient serum and positively correlated with thyroglobulin antibody (r ≥ 0.6, P < 0.05). Furthermore, luciferase assay demonstrated CLDN1 was the direct target gene of miR-142-5p (P < 0.05), and Immunohistochemical staining showed a reverse expression patterns with miR-142-5p and CLDN1. Overexpression of miR-142-5p in thyrocytes resulted in reducing of the expression of claudin-1 both in mRNA and protein level (P = 0.032 and P = 0.009 respectively) and increasing the permeability of thyrocytes monolayer (P < 0.01).

Conclusions

Our findings indicate a previously unrecognized mechanism that miR-142-5p, targeting CLDN1, plays an important role in HT pathogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0917-6) contains supplementary material, which is available to authorized users.

Increases of microRNA let-7e in peripheral blood mononuclear cells in Hashimoto's disease

MicroRNA (miRNA) is a family of non-coding RNAs that have important roles in various vital functions. It has been reported that let-7e, a miRNA, may be involved in the regulation of interleukin (IL)-10 production. The purpose of this study was to evaluate the role of let-7e as a regulator of IL-10 production in the pathological processes of autoimmune thyroid diseases (AITDs). We evaluated the association between let-7e expression and intracellular expression of IL-10 in the peripheral blood mononuclear cells (PBMCs) collected from 11 healthy volunteers. Then we investigated the expression levels of let-7e in the PBMCs of 50 patients with Graves' disease (GD), 42 patients with Hashimoto's disease (HD) and 28 healthy controls. We found negative correlations between the expression level of let-7e and IL-10 messengerRNA (mRNA) and between the expression level of let-7e and proportion of IL-10(+) cells in stimulated PBMCs from healthy volunteers (r = -0.44, p = 0.0267 and r = -0.49, p = 0.0166, respectively). The expression levels of let-7e were significantly increased in HD patients compared with those in GD patients and healthy volunteers (p = 0.0003 and p = 0.0011, respectively). let-7e may be associated with the pathogenesis of HD through the regulation of intracellular IL-10 expression.

A Single-Nucleotide Polymorphism in 3'-Untranslated Region of Endothelin-1 Reduces Risk of Dementia After Ischemic Stroke

BACKGROUND Ischemic stroke is widely recognized as a major health problem and social burden worldwide, and it usually leads to dementia. In this study, we aimed to better understand the pathogenesis in the development of dementia following ischemic stroke. MATERIAL AND METHODS We exploited miRNA database to search for the target for miR-125a and validated the found target using luciferase assay. Further, we performed real-time PCR and Western blot analysis to examine the expression of miR-125a and its target in the tissue samples. In addition, a polymorphism was genotyped and its association with post-stroke dementia was analyzed. RESULTS We identified enthothelin-1 (ET-1) as a target of miR-125a, and this relationship was validated using luciferase assay. Furthermore, transfection of miR-125a inhibitor substantially upregulated the expression of ET-1, while miR-125a and ET-1 siRNA caused downregulation of ET-1 in endothelial cells. In addition, we found that a polymorphism (rs12976445) interferes with the expression of miR-125a, which in turn caused an increase in the expression of ET-1 in human endothelial cells. Logistic regression analysis showed that rs12976445 is significantly associated with the risk of dementia after ischemic stroke. CONCLUSIONS Our study demonstrated the pathogenesis mechanism during the development of dementia after ischemic stroke by investigating the relationship between miR-125a and its target ET-1, promising a potential pathological solution for post-stroke dementia in the future.

Rs12976445 Polymorphism is Associated with Risk of Diabetic Nephropathy Through Modulating Expression of MicroRNA-125 and Interleukin-6R

BACKGROUND

Diabetic nephropathy (DN) is one of the most significant long-term complications of diabetes mellitus (DM), and it is a primary risk factor for end-stage renal disease. MicroRNAs (miRNAs) play important roles in regulating the expression of genes, including interleukin-6R (IL-6R), which has been reported to be involved in the development of DNDN. The aim of this study was to identify the dysregulation of miRNA and its target responsible for the development of DN in DM.

MATERIAL AND METHODS

We collected the kidney tissues from patients with DN (N=36) and control patients (N=28), and performed real-time PCR and Western blot analysis to determine the expression of IL-6R. Computational analysis and luciferase assay were used to identify the miRNA that regulates IL-6R. To explore the association between rs12976445 polymorphism and risk of DN, we enrolled 594 DM patients with (N=282) or without DN (N=312), and studied the association between a variant in miR-125a and risk of DN in DM.

RESULTS

The expression of IL-6R was barely detected in the control groups, while in the DN group, the IL-6R was clearly detectable. Next, miR-125a was identified as a regulator of IL-6R by using informatics analysis and luciferase assay. A single-nucleotide polymorphism (rs12976445) in pri-miR-125a has been shown to compromise the mature processing of miR-125a, and we showed that the expression levels of miR-125a was comparable between individuals carrying TT and CT, and when combined into 1 group, the miR-125a expression was approximately 3 times lower than in the CC group. We found significant differences regarding rs12976445 genotype distribution between the DN and the control (OR=1.45, 95% C.I.=1.02-2.08, p<0.05) with the possible confounding factors adjusted for by using logistic regression analysis.

CONCLUSIONS

We identified miR-125a as a direct regulator of IL-6R, and the genotype of rs12976445 might be a novel predictor of the development of DN in DM.

MicroRNA-125-5p targeted CXCL13: a potential biomarker associated with immune thrombocytopenia

BACKGROUND

Immune thrombocytopenia (ITP) is an acquired and autoimmune disease of adults and children characterized by decreased platelet production. CXC chemokine ligand-13 (CXCL13) participates in multiple immunological responses. However, it is still unknown the relationship between CXCL13 and ITP.

METHODS

Plasma CXCL13 was detected in ITP (n = 30) children. CD4+ T cells was isolated from peripheral blood mononuclear cells (PBMCs) from healthy volunteers. Treated CD4+ T cells with dexamethasone and/or miR-125-5p mimic/inhibitor, to observe the regulation of CXCL13.

RESULTS

Compared with controls, ITP children had elevated plasma CXCL13, the concentration of which was reduced after treatment. In vitro, dexamethasone decreased CXCL13 level in in dose- dependent and in time-dependent manner. MiR-125-5p mimic decreased CXCL13 level and miR-125-5p inhibitor increased CXCL13 level in CD4+ T cells. CXCL13 was implied to be target gene of miR-125-5p. MiR-125-5p inhibitor also canceled dexamethasone induced decrease of CXCL13.

CONCLUSION

CXCL13 is the target gene of miR-125-5p, which is possibly involved in the pathological process of ITP.

Association between miR-125a rs12976445 and survival in breast cancer patients

MicroRNAs (miRNAs) act as an oncogene or a tumor suppressor by negatively regulating target genes. Genetic variants in miRNA genes confer susceptibility to cancer and risk of death in cancer patients. The aim of this study was to investigate whether miRNA polymorphisms were associated with survival in breast cancer patients. Five miRNA polymorphisms (miR-26a1 rs7372209, miR-125a rs12976445, miR-218 rs11134527, miR-423 rs6505162, and miR-608 rs4919510) were genotyped in 196 breast cancer patients. We found that miR-125a rs12976445 was significantly associated with survival in codominant, recessive, and dominant models. However, only association under the codominant model remained significant after adjustment for lymph node metastasis, TNM stage, estrogen receptor, and progesterone receptor. Furthermore, this effect remained in stratification analysis. In conclusion, our results provide evidence that miR-125a rs12976445 may serve as a prognostic biomarker for breast cancer. Further large-scale studies are required to confirm these findings.