The Role of MicroRNAs in Autoimmune Diseases with Skin Involvement

PanomiR: a systems biology framework for analysis of multi-pathway targeting by miRNAs

Charting microRNA (miRNA) regulation across pathways is key to characterizing their function. Yet, no method currently exists that can quantify how miRNAs regulate multiple interconnected pathways or prioritize them for their ability to regulate coordinate transcriptional programs. Existing methods primarily infer one-to-one relationships between miRNAs and pathways using differentially expressed genes. We introduce PanomiR, an in silico framework for studying the interplay of miRNAs and disease functions. PanomiR integrates gene expression, mRNA-miRNA interactions and known biological pathways to reveal coordinated multi-pathway targeting by miRNAs. PanomiR utilizes pathway-activity profiling approaches, a pathway co-expression network and network clustering algorithms to prioritize miRNAs that target broad-scale transcriptional disease phenotypes. It directly resolves differential regulation of pathways, irrespective of their differential gene expression, and captures co-activity to establish functional pathway groupings and the miRNAs that may regulate them. PanomiR uses a systems biology approach to provide broad but precise insights into miRNA-regulated functional programs. It is available at https://bioconductor.org/packages/PanomiR.

Total oxidant capacity, total antioxidant capacity, ischemic modified albumin, microRNA levels, and their relationship with psoriasis area and severity index

Aims To examine the differences in the levels of microRNA, ischemic modified albumin (IMA), total oxidant capacity (TOC), and total antioxidant capacity (TAC) of persons with and without psoriasis and, in the case group, the relationship between these parameters and psoriasis area and severity index (PASI). Methods Blood samples were collected from patients and healthy participants to examine levels of these parameters. Results The mean serum TOC level was higher in the case group. The mean serum TAC and IMA levels were significantly lower in the case group (P <0.001). It was observed that the mean serum miR-203 and miR-146a levels were increased in psoriasis patients. It was determined that there was only a significant positive weak correlation between miR-203 and PASI (r = 0.232, P = 0.027). Limitations The small sample size, not controlling serum albumin and not evaluating the effects of the treatment agents used by the patients on oxidative and inflammatory processes. Conclusion In the case group changes in the mean serum TOC and TAC levels provide evidence that oxidative stress may play a critical role in disease pathogenesis. The increase in the mean serum miR-203 and miR-146a levels suggest the possibility of therapies targeting these microRNAs as a new option.

Expression Signature of Immune-Related MicroRNAs in Autoimmune Skin Disease: Psoriasis and Vitiligo Insights

BACKGROUND

Psoriasis and vitiligo are both chronic, skin-specific diseases classified as autoimmune diseases due to the involvement of several biochemical pathways in their pathogenesis, similar to those altered in other autoimmune diseases. The role of miRNAs in regulating skin autoimmune function has yet to be fully characterized.

AIM

The aim of this study was to assess the expression profile of a panel of 11 circulating immune-related miRNAs in patients with autoimmune skin diseases, specifically psoriasis and vitiligo, and correlate their expression signature with the clinicopathological features of the diseases.

SUBJECTS AND METHODS

Relative gene expression quantification for 11 immune-related circulating miRNAs in plasma was done for 300 subjects-100 patients with psoriasis, 100 patients with vitiligo and 100 normal healthy volunteers-followed by different modalities of bioinformatics analysis for the results.

RESULTS

The expression levels of all the studied immune-related miRNAs were elevated in both autoimmune skin disorders, with much higher levels of expression in psoriasis than in vitiligo patients. There was a significant correlation between most of the studied miRNAs, suggesting shared target genes and/or pathways. Moreover, all the studied miRNAs showed significant results as biomarkers for autoimmune skin disease, with miRNA-145 being the best candidate. Regarding the clinicopathological data, miRNA-7, miRNA-9, miRNA-145, miRNA-148a, and miRNA-148b were positively correlated with age. All the miRNAs were inversely correlated with obesity and disease duration.

CONCLUSION

This study highlights the critical role of miRNAs in skin-specific autoimmune diseases that proved to be potential biomarkers for autoimmune skin disorders, warranting their exploration as therapeutic targets.

Endometriosis and Systemic Lupus Erythematosus: Systematic Review and Meta-analysis

Endometriosis is a chronic gynaecological condition characterized by inflammatory and immune abnormalities. Likewise, these dysfunctions are important hallmarks of systemic lupus erythematosus (SLE), a condition that also has a high prevalence among women in reproductive age. Therefore, we conducted a systematic review and meta-analysis to investigate the association between endometriosis and SLE. We searched Medline and Web of Science for articles published from database inception to March 1, 2021. Random-effects meta-analysis was performed to provide a pooled risk ratio (RR). Individual study quality was evaluated following the National Heart, Lung, and Blood Institute Quality Assessment Tools (NHLBI QAT). From the 225 articles identified through our search, five studies-assessing 152,355 women-were included. Included studies presented an overall poor or fair quality rating. We observed a significant association between endometriosis and SLE (RR = 2.47, 95% confidence interval: 1.33-4.59, P < 0.004, I2 = 54%). Sensitivity analyses stratifying articles by study design demonstrated that the association was significant in cross-sectional and case-control studies (RR = 5.07, 95% confidence interval: 1.42-18.11, P < 0.012), as well as in cohort studies (RR = 2.07, 95% confidence interval: 1.02-4.20, P < 0.044). In spite of the limited quality of included studies, our results suggest the existence of an association between endometriosis and SLE. These findings can aid medical assessment of patients with endometriosis, as well as provide further insights to better understand this gynaecological disorder.

Critical Role of Gut Microbiota and Epigenetic Factors in the Pathogenesis of Behçet's Disease

Behçet’s disease (BD) is a chronic refractory multisystem autoinflammatory disease, characterized by typical clinical features of non-specific vasculitis, oral and genital ulcers, uveitis, as well as skin lesions. The exact etiopathogenesis of BD remains unknown, existing studies have indicated that genetics and environmental factors contribute to the increased development of BD. Recently, several studies have shown that external environmental factors can affect the process of epigenetic modification, and abnormalities of epigenetic factors have been confirmed to be involved in the occurrence of BD. At the same time, abnormalities of gut microbiota (GM) in the body, have also been confirmed to participate in the pathogenesis of BD by regulating the balance of Th17/Tregs. This article reviews the pathogenesis of BD and summarizes numerous clinical studies, focusing on the mechanism of GM and epigenetic factors impacting on BD, and providing new ideas for further elucidating the pathogenesis of BD.

Localized scleroderma: actual insights and new biomarkers

Localized scleroderma (LS, morphea, limited scleroderma, focal scleroderma) is a chronic autoimmune disease characterized by a progressive damage to the connective tissue with a predominance of fibrosclerotic disorders in the skin and the subcutaneous tissue. In addition surrounding structures may be affected: fascia, muscle, and bone tissues. This review reflects the current understanding about limited scleroderma, its pathogenesis, diagnosis, new biomarkers, and information about the possibilities of its transition to systemic scleroderma. The following new biomarkers have been identified: galactosylated IgG (Ig-Gal), progranulin (PGRN), chemokine CCXL 18, various types of microRNA (miRNA-let-7a, miRNA-7, miRNA-196a, miRNA-155, miRNA-483-5p), periostin, and myelin basic protein (MBP). Knowledge about new biomarkers of LS will help us to explore the patients' predisposition to the development of systemic scleroderma. In addition, by acting on these biomarkers, it is possible to prevent the progression of LS in the early stages and its transition to systemic scleroderma. The review also presents the current understanding of autoantibodies in LS and their correlation with clinical signs of the disease.

Epigenetics in Non-tumor Immune-Mediated Skin Diseases

Epigenetics is the study of the mechanisms that regulate gene expression without modifying DNA sequences. Knowledge of and evidence about how epigenetics plays a causative role in the pathogenesis of many skin diseases is increasing. Since the epigenetic changes present in tumor diseases have been thoroughly reviewed, we believe that knowledge of the new epigenetic findings in non-tumor immune-mediated dermatological diseases should be of interest to the general dermatologist. Hence, the purpose of this review is to summarize the recent literature on epigenetics in most non-tumor dermatological pathologies, focusing on psoriasis. Hyper- and hypomethylation of DNA methyltransferases and methyl-DNA binding domain proteins are the most common and studied methylation mechanisms. The acetylation and methylation of histones H3 and H4 are the most frequent and well-characterized histone modifications and may be associated with disease severity parameters and serve as therapeutic response markers. Many specific microRNAs dysregulated in non-tumor dermatological disease have been reviewed. Deepening the study of how epigenetic mechanisms influence non-tumor immune-mediated dermatological diseases might help us better understand the role of interactions between the environment and the genome in the physiopathogenesis of these diseases.

Thymoquinone in autoimmune diseases: Therapeutic potential and molecular mechanisms

Autoimmune diseases (AUDs) are a multifactorial disease, among which rheumatoid arthritis, systemic lupus erythematosus and multiple sclerosis are more prevalent. Several anti-inflammatory, biologics, and AUD-modifying drugs are found effective against them, but their repeated use are associated with various adverse effects. In this review article, we have focused on the regulation of inflammatory molecules, molecular signaling pathways, immune cells, and epigenetics by natural product thymoquinone on AUDs. Studies indicate that thymoquinone can regulate inflammatory molecules including interferons, interleukins, tumor necrosis factor-α (TNF-α), oxidative stress, regulatory T cells, and various signaling pathways such as nuclear factor kappa beta (NF-κβ), janus kinase/signal transduction and activator of transcription (JAK-STAT), mitogen-activated protein kinase (MAPK) at the molecular level and epigenetic alteration. As these molecules and signaling pathways with defective immune function play an important role in AUD development, controlling these molecules and deregulated molecular mechanism is a significant feature of AUD therapeutics. Interestingly thymoquinone is reported to possess all these potential. This article reviewed the deregulated mechanism of AUDs, and the action of thymoquinone on inflammatory molecules, immune cells, signaling pathways, and epigenetic machinery. Thymoquinone can be regarded as a potential drug candidate for AUD treatment.

MicroRNAs in Several Cutaneous Autoimmune Diseases: Psoriasis, Cutaneous Lupus Erythematosus and Atopic Dermatitis

MicroRNAs (miRNAs) are endogenous small non-coding RNA molecules that regulate the gene expression at a post-transcriptional level and participate in maintaining the correct cell homeostasis and functioning. Different specific profiles have been identified in lesional skin from autoimmune cutaneous diseases, and their deregulation cause aberrant control of biological pathways, contributing to pathogenic conditions. Detailed knowledge of microRNA-affected pathways is of crucial importance for understating their role in skin autoimmune diseases. They may be promising therapeutic targets with novel clinical implications. They are not only present in skin tissue, but they have also been found in other biological fluids, such as serum, plasma and urine from patients, and therefore, they are potential biomarkers for the diagnosis, prognosis and response to treatment. In this review, we discuss the current understanding of the role of described miRNAs in several cutaneous autoimmune diseases: psoriasis (Ps, 33 miRNAs), cutaneous lupus erythematosus (CLE, 2 miRNAs) and atopic dermatitis (AD, 8 miRNAs). We highlight their role as crucial elements implicated in disease pathogenesis and their applicability as biomarkers and as a novel therapeutic approach in the management of skin inflammatory diseases.

Circulating miRNA-181b-5p, miRNA-223-3p, miRNA-210-3p, let 7i-5p, miRNA-21-5p and miRNA-29a-3p in patients with localized scleroderma as potential biomarkers

Localized scleroderma (LoSc) is a rare disease manifested by an inflammation and sclerosis of the skin. The latest studies focused on glycoprotein Krebs von den Lungen-6, surfactant protein-D, chemokine ligand 18 and dipeptidylpeptidase 4 as potential biomarkers of skin fibrosis in systemic scleroderma. Our study aimed to identify 6 miRNAs with elevated or decreased levels in 38 LoSc patients (31 females, 7 males) compared to healthy volunteers (HVs) and to correlate the selected miRNAs' serum levels with the severity and the clinical symptoms of LoSc and some laboratory parameters with the selected miRNAs' serum levels. The serum levels of miRNAs, i.e. miRNA-181b-5p, miRNA-223-3p, miRNA-21-5p, let 7i-5p, miRNA-29a-3p and miRNA-210-3p were significantly increased in the LoSc patients compared to the HVs. The level of let-7i increase in the female LoSc patients correlated negatively with BSA (r =  - 0.355, p = 0.049) and mLoSSI (r =  - 0.432, p = 0.015). Moreover, the female patients with inactive LoSc had significantly higher level of let-7i (2.68-fold on average) in comparison to those with active disease (p = 0.045). The exact role of those molecules has not been revealed in LoSc and a long-term longitudinal research is pivotal to confirm their prognostic value.

MiR-506-3p regulates autophagy and proliferation in post-burn skin fibroblasts through post-transcriptionally suppressing Beclin-1 expression

MicroRNAs (miRNAs) is involved in diverse biological processes of cells including dermal fibroblasts that contributed to wound healing and resulted in keloid scarring. MiR-506-3p has been identified as a tumor suppressor or oncogene in fibroblasts of various cancers, while the role of miR-506-3p in regulating functions of post-burn dermal fibroblasts is poorly known. In this study, miR-506-3p was confirmed to be significantly downregulated in burned tissues and heat-stimulated dermal fibroblasts. Expression levels of autophagy-related proteins suggested thermal stimulus promoting the autophagy in dermal fibroblasts. Then, miR-506-3p inhibition enhanced cell proliferation and cell cycle process in dermal fibroblasts after thermal stimulus, whereas overexpression of miR-506-3p showed the opposite effect. Western blot assay showed that inhibition of miR-506-3p resulted in the upregulation of the expression levels of LC3-II, ATG5, and structural protein collagen I, as well as the downregulation of p62. Marker proteins of intermolecular cross-links in collagen synthesis, including hydroxylysylpyridinoline (HP), lysinepyridine (LP), and lysyl hydroxylase 2 (LH2), were increased by miR-506-3p overexpression and decreased by miR-506-3p inhibition. Moreover, transfection with miR-506-3p mimic suppressed the proliferation and autophagy in heat-stimulated dermal fibroblasts in a dose-dependent manner. Subsequently, dual luciferase reporter gene assay demonstrated that Beclin-1 was a direct target of miR-506-3p, and reintroduction of Beclin-1 could antagonize the suppressive effect of miR-506-3p overexpression on fibroblast proliferation, autophagy, and the intermolecular cross-links in collagen synthesis. Taken together, our findings showed that miR-506-3p regulated autophagy and proliferation in post-burn skin fibroblasts through post-transcriptionally suppressing Beclin-1 expression.

miRNAs in drug response variability: potential utility as biomarkers for personalized medicine

MicroRNAs (miRNAs) are 18-22 nucleotide RNA molecules that modulate the expression of multiple protein-encoding genes at the post-transcriptional level. Almost all physiological conditions are probably modulated by miRNAs, including pharmacological response. Indeed, acting on the regulation of numerous genes involved in the pharmacokinetics and pharmacodynamics of drugs, differences in the levels of circulating miRNAs or genetic variants in the sequences of the miRNA genes can contribute to interindividual variability in drug response, both in terms of toxicity and efficacy. For their stability in body fluids and the easy availability and accurate quantification, miRNAs could be ideal biomarkers of individual response to drugs. This review aims to give an overview on the available studies that have investigated the relationship between miRNAs and response to drugs in different classes of diseases and considered their possible clinical application as therapy response predictive biomarkers. A comprehensive search was conducted from the international web database PubMed. We included papers that investigated the relationship between miRNAs and response to drugs, published before January 2019.

MicroRNA in localized scleroderma: a review of literature

Localized scleroderma (LoSc) is rare connective tissue disease that manifests with inflammation and fibrosis of the skin. Depending on the LoSc subtype, adjacent structures such as subcutaneous tissue, fascia, muscles, bones may be affected. The hallmark of fibrosis is tissue remodelling with excess deposition of extracellular matrix proteins (ECM), principally collagens. MicroRNAs (miRNAs) are small, noncoding RNA molecules that consist of 19-24 nucleotides and act as negative regulators of gene expression at the posttranscriptional level. Based on the current articles, approximately 40 microRNAs have been linked to fibrosis in different organs and diseases. The majority of these molecules promote or inhibit fibrosis by targeting connective tissue growth factor (CTGF), extracellular matrix proteins, TGF-β pathway and MAPK (mitogen-activated protein kinase) pathway. Further, particular microRNAs regulate fibrogenesis by altering epithelial-to-mesenchymal transition (EMT) or activating proliferation of myofibroblasts. MiRNAs are relatively stable, detectable in tissues and body fluids (serum, plasma) which suggest that they may serve as beneficial biomarkers to monitor the course of the disease and response to treatment. Herein, we report the present state of knowledge on microRNA expression in localized scleroderma.

A novel miRNA-4484 is up-regulated on microarray and associated with increased MMP-21 expression in serum of systemic sclerosis patients

Systemic sclerosis (SSc) is a complex, heterogeneous connective tissue disease, characterized by fibrosis and ECM deposition in skin and internal organs, autoimmunity, and changes in the microvasculature. Profiling of circulating miRNAs in serum has been found to be changed in pathological states, creating new possibilities for molecular diagnostics as blood-based biomarkers. This study was designed to identify miRNAs that are differentially expressed in SSc and might be potentially contributing to the disease etiopathogenesis or be used for diagnostic purposes. Thus, we compared the expression pattern of multiple miRNAs in serum of 10 SSc patients to 6 healthy controls using microarray analysis, and RT-qPCR to confirm the obtained results. In addition, bioinformatics analysis was performed to explore miRNAs target genes and the signaling pathways that may be potentially involved in SSc pathogenesis. Our study shows a different expression of 15 miRNAs in SSc patients. We identified that miR-4484, located on chromosome 10q26.2, was an 18-fold up-regulated in SSc patients compared to a control group. Bioinformatics analysis of the miR-4484 target genes and the signaling pathways showed that it might be potentially involved in the TGF-β signaling pathway, ECM-receptor interaction, and metalloproteinases expression. Based on the chromosomal location, the most interesting target gene of miR-4484 may be MMP-21. We found that the expression of MMP-21 significantly increased in SSc patients compared to healthy subjects (P < 0.05). Our results suggest that miR-4484, and MMP-21 might be novel serum biomarkers that may correspond to pathological fibrosis in SSc, but it needs to be validated in further studies.

Correlation of myomir-206 and proinflammatory cytokines (IL-16 and IL-17) in patients with rheumatoid arthritis

Introduction

Rheumatoid arthritis (RA) is a persistent autoimmune disease in which the activity of proinflammatory cytokines and the imbalance, related to the inflammatory process, between elements of bone tissue remodeling such as osteoclasts and osteoblasts play a key role in development of erosions and bone destruction. MicroRNAs are important regulators of skeletal remodeling and are involved in RA pathogenesis. Myomir-206 (miR-206) is unrivalled among the myomirRs, where it is expressed in skeletal muscle and either absent or minimally expressed in other tissues

Material and methods

This study was designed to analyze the miR-206 expression pattern in peripheral blood mononuclear cells (PBMCs) using quantitative real time polymerase chain reaction and its correlation with IL-16/IL-17 proinflammatory cytokines in two groups – 20 healthy individuals and 30 patients with RA.

Results

Elevated expression of miR-206 was observed in RA patients compared with healthy controls (p < 0.001). A significant increase in both IL-17 and IL-16 serum levels was found in the RA group (p < 0.01 and p < 0.05; respectively) compared to the control group. miR-206 expression level and IL-17 production were directly positively correlated (r = 0.491; p < 0.01). ROC analysis of miR-206 showed a cutoff value of 2.7 with 70% sensitivity, 85% specificity, and the area under the curve was 0.802 (p < 0.001) with the 95% confidence interval from 0. 676 to 0.927

Conclusions

Taken together, our results indicate the importance of miR-206 expression in patients with RA, as a potential new biomarker that affects bone loss/deformity and its collaborative role with proinflammatory cytokines such as IL-16 and IL-17 in RA bone metabolism. Particular interest should be given to further research to determine the contribution of expression of miR-206 in RA pathogenesis

The Aberrant Epigenetic Modifications in the Pathogenesis of Psoriasis

Psoriasis is a chronic and recurrent inflammatory skin disease that is characterized by abnormal keratinocyte proliferation, vascular hyperplasia, and infiltration of inflammatory cells into the dermis and epidermis. It is generally accepted that the central pathogenesis of psoriasis is dysfunction of T lymphocytes, which are affected by the complex interplay between genetic and environmental factors, including trauma, infections, stress, drugs, smoking, and alcohol consumption (Nestle et al., 2009). The environmentally induced epigenetic changes, including DNA methylation, histone modification, and microRNAs, have been shown to be involved in the pathogenesis of this disease (Zhang et al., 2012).

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.

MicroRNA implications in the etiopathogenesis of ankylosing spondylitis

Ankylosing spondylitis (AS) is a chronic immune-mediated inflammatory disease that affects both axial and peripheral skeletons as well as soft tissues. Recent investigations offer that disease pathogenesis is ascribed to a complex interplay of genetic, environmental, and immunological factors. Until now, there is no appropriate method for early diagnosis of AS and the successful available therapy for AS patients stay largely undefined. MicroRNAs (miRNAs), endogenous small noncoding RNAs controlling the functions of target mRNAs and cellular processes, are present in human plasma in a stable form and have appeared as possible biomarkers for activity, pathogenesis, and prognosis of the disease. In the present review, we have tried to summarize the recent findings related to miRNAs in AS development and discuss the possible utilization of these molecules as prognostic biomarkers or important therapeutic strategies for AS. Further examinations are needed to determine the unique miRNAs signatures in AS and characterize the mechanisms mediated by miRNAs in the pathology of this disease.

Cadherin 6 is activated by Epstein-Barr virus LMP1 to mediate EMT and metastasis as an interplay node of multiple pathways in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is an epithelial malignancy, which is notorious among head-and-neck cancers with its metastatic feature. Epstein–Barr virus (EBV) infection plays a fundamental role in NPC development with the mechanism is not well understood. Here we demonstrate that EBV oncoprotein LMP1 drives EMT and metastasis of NPC by reactivating the adhesion molecule, cadherin 6 (CDH6), which normally occurs in embryogenesis with unknown role in NPC. CDH6 was found to be upregulated in LMP1-positive NPC tissues, and was identified as a target of the epithelium-specific miR-203. LMP1-activated NF-κB transcriptionally repressed the miR-203 expression by binding to the promoter region of miR-203 gene. CDH6 activation in turn induced EMT and promoted metastasis in NPC. CDH6 depletion, NF-κB inhibitor and miR-203 overexpression were able to impair the EMT effects. The miR-203 downregulation in NPC tissues was strongly associated with metastasis clinically. The CDH6 activator, Runt-related transcription factor 2 (RUNX2), was also activated by EBV in the event. For both CDH6 and RUNX2 are components at TGF-β downstream, CDH6 became a node protein for the interplay of multiple signalings including NF-κB and TGF-β. Therefore, the switch-on of miR-203 was important for nasopharyngeal epithelial cells to maintain normal phenotype. This study demonstrates that EBV has evolved sophisticated strategies by driving epithelial cells to obtain malignant features, particularly in NPC metastasis, providing novel biomarkers for the therapy and prognosis of EBV-associated NPC.

Genome-Wide MicroRNA Analysis Implicates miR-30b/d in the Etiology of Alopecia Areata

Alopecia areata (AA) is one of the most common forms of human hair loss. Although genetic studies have implicated autoimmune processes in AA etiology, understanding of the etiopathogenesis is incomplete. Recent research has implicated microRNAs, a class of small noncoding RNAs, in diverse autoimmune diseases. To our knowledge, no study has investigated the role of microRNAs in AA. In this study, gene-based analyses were performed for microRNAs using data of the largest genome-wide association meta-analysis of AA to date. Nominally, significant P-values were obtained for 78 of the 617 investigated microRNAs. After correction for multiple testing, three of the 78 microRNAs remained significant. Of these, miR-30b/d was the most significant microRNA for the follow-up analyses, which also showed lower expression in the hair follicle of AA patients. Target gene analyses for the three microRNAs showed 42 significantly associated target genes. These included IL2RA, TNXB, and ERBB3, which had been identified as susceptibility loci in previous genome-wide association studies. Using luciferase assay, site-specific miR-30b regulation of the AA risk genes IL2RA, STX17, and TNXB was validated. This study implicates microRNAs in the pathogenesis of AA. This finding may facilitate the development of future treatment strategies.

Polymorphisms in MIR122, MIR196A2, and MIR124A Genes are Associated with Clinical Phenotypes in Inflammatory Bowel Diseases

BACKGROUND

Inflammatory bowel diseases (IBDs), including Crohn's disease (CD) and ulcerative colitis (UC), are multifactorial disorders that result from a dysregulated inflammatory response to environmental factors in genetically predisposed individuals. Recently, microRNAs (miRNAs) have been shown to be involved in the development of IBDs.

AIMS

We investigated common variants in five miRNA genes in a cohort of Italian IBD patients, to evaluate their possible role in the disease's susceptibility and phenotype manifestations.

METHODS

The analysis included 267 CD patients, 207 UC patients, and 298 matched healthy controls. Polymorphisms in the MIR122, MIR499, MIR146A, MIR196A2, and MIR124A genes were evaluated by allelic discrimination assay.

RESULTS

We did not find associations between mir polymorphisms and IBD susceptibility. In both diseases, rs17669 and rs11614913 (MIR122 and MIR196A2) seem to contribute to clinical phenotypes: ileal location in CD (odds ratio [OR] = 1.82, p = 0.03; OR = 0.51, p = 0.01), and left-sided extent in UC (OR = 0.43, p = 0.05; OR = 0.28, p = 0.002). In CD, the MIR124A polymorphism (rs531564) contributed to colon location (p = 0.03, OR = 2.74). Finally, the variant allele of rs11614913 was associated with early age at onset in both diseases (p = 0.05 and p = 0.02).

CONCLUSIONS

We showed for the first time that polymorphisms in MIR122, MIR196A2, and MIR124A could play a role in clinical phenotype modulation in IBD.

Roles of microRNAs in psoriasis: Immunological functions and potential biomarkers

MicroRNAs (miRNAs) are small non-coding RNA molecules, which function in RNA silencing and post-transcriptional regulation of gene expression. Psoriasis is an inflammatory skin disease characterized by the dysfunction of keratinocytes, with the immune dysregulation. We reviewed the recent studies on the roles of miRNAs in psoriasis and showed that miRNAs play key roles in psoriasis, including the regulation of hyperproliferation, cytokine and chemokine production in keratinocyte, as well as mediating immune dysfunction in psoriasis. Furthermore, miRNAs, particularly, circulating miRNAs may serve as novel biomarkers for diagnosis, monitoring therapy response and reflecting the disease severity. Thus, targeting specific miRNAs may be used to develop new therapeutic methods for psoriasis.

Psoriasis in systemic lupus erythematosus: a single-center experience

The coexistence of psoriasis with systemic lupus erythematosus (SLE) has been reported in limited case series, raising hypotheses about shared pathogenetic mechanisms. Nevertheless, important differences regarding treatment do exist. The aim of the present study was to determine the prevalence and characteristics of psoriasis in a defined cohort of lupus patients. Patients with psoriasis were retrieved from the University of Toronto Lupus Clinic from its inception in 1970 up to 2015. Charts were hand-searched to collect information concerning demographic, clinical, and therapeutic variables. Patients were matched with non-psoriasis lupus patients to identify the impact of supervening psoriasis on lupus activity, damage accrual, and venous thromboembolic (VTEs) and cardiovascular events (CVEs). Psoriasis was diagnosed in 63 patients (49 females, 14 males) for a prevalence of 3.46% (63/1823). The male-to-female ratio was significantly higher in non-psoriasis patients (0.286 vs. 0.138, p = 0.017). Plaque psoriasis was the most prominent type (55/63, 87.3%) whereas three patients had pustular disease; one had psoriatic arthritis. Nine patients (14.3%) were administered systemic treatment with methotrexate (n = 5), azathioprine (n = 1), ustekinumab (n = 3), and etanercept (n = 1). Psoriasis was definitely deteriorated by hydroxychloroquine in one patient. There was no significant impact of psoriasis on disease activity, damage accrual, VTEs, and CVEs. The prevalence of psoriasis was twice as high as that of the general Canadian population in this lupus cohort. Plaque psoriasis was the most prominent subtype, and topical treatment was adequate in the majority of patients. Supervening psoriasis had no significant impact on lupus activity and damage accrual.

MicroRNA-146a suppresses IL-17-mediated skin inflammation and is genetically associated with psoriasis

BACKGROUND

Psoriasis is an immune-mediated inflammatory skin disease with a strong genetic background in which activation of IL-17 signaling is central in the pathogenesis. Little has been known about the role of noncoding RNAs, including microRNAs (miRNAs), in predisposition to the disease.

OBJECTIVE

We sought to investigate the genetic association of single nucleotide polymorphisms in microRNA-146a (miR-146a) to psoriasis and to explore its function in the initiation and resolution of the disease.

METHODS

Analysis of the genetic association of miR-146a rs2910164 and psoriasis was carried out on 1546 patients with psoriasis and 1526 control subjects. The role of miR-146a in patients with psoriasis was assessed by using miR-146a^-/- mice in conjunction with the imiquimod-induced mouse model of psoriasis. The severity of psoriasis-like skin inflammation was evaluated at morphologic, histologic, and molecular levels. miR-146a was ectopically overexpressed and inhibited in keratinocytes treated with IL-17. Synthetic miR-146a was injected intradermally into mice.

RESULTS

Here we report protective association of a functional polymorphism in the miR-146a precursor (rs2910164). Genetic deficiency in miR-146a leads to earlier onset and exacerbated pathology of skin inflammation, with increased expression of IL-17-induced keratinocyte-derived inflammatory mediators, epidermal hyperproliferation, and increased neutrophil infiltration. Moreover, miR-146a-deficient mice do not resolve inflammation after discontinuation of imiquimod challenge. The overexpression of miR-146a suppressed, whereas its inhibition enhanced, IL-17-driven inflammation in keratinocytes. Functionally, miR-146a impairs the neutrophil chemoattractant capacity of keratinocytes. Finally, delivery of miR-146a mimics into the skin leads to amelioration of psoriasiform skin inflammation, decreased epidermal proliferation, and neutrophil infiltration.

CONCLUSIONS

Our results define a crucial role for miR-146a in modulating IL-17-driven inflammation in the skin.

Inhibitory effect of G2013 molecule as a novel immunomodulatory agent, on miR-155 gene expression in HEK-Blue hTLR4 cell line

Lack of regulation of microRNAs (miRNAs) expression has been observed in some autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. G2013, as a novel non-steroidal anti-inflammatory drug (NSAID) with the immunomodulatory property, has been shown the positive effects in multiple sclerosis and anti-ageing experimental models. This research aimed to study the inhibitory effect of G2013 on miR-155 gene expression using HEK-Blue hTLR4 and Null2 cell lines. Total RNA was extracted from the treated and control cells. cDNA was made for miRNA and expression levels of miR-155 were detected by quantitative Real-time PCR using a specific primer together with U6 as the internal reference gene. A non-significant reduction was observed in the gene expression level of miR-155 in the HEK-Blue hTLR4 and Null2 cell lines under the influence of a low dose of G2013. In contrast, adding lipopolysaccharide (LPS) to the mentioned cells led to a significant increase in miR-155 expression, whereas addition of LPS four hours after exposing the cells with G2013 could not increase the expression level of this miRNA ( P < 0.05). Collectively, this research showed that G2013, as a novel NSAID with immunomodulatory property is able to significantly decrease the gene expression of miR-155 following stimulation by LPS.

MicroRNAs differentially expressed in Behçet disease are involved in interleukin-6 production

Background

Behcet’s disease (BD) is characterized by systemic recurrent inflammation with increased production of tumor necrosis factor (TNF)–α and interleukin (IL)-6 by peripheral blood mononuclear cells (PBMCs). To gain insight into the underlying mechanisms of this disease, the expression levels of distinct microRNAs in PBMCs of BD patients were determined and their association with TNF-α and IL-6 production was evaluated.

Findings

The expression levels of microRNAs, miR-638 and miR-4488, were reduced in patients with stable BD in comparison with healthy controls. In addition, the expression of miR-3591-3p was increased in patients with active BD when compared to patients with stable BD. Transfection of miR-638 and miR-4488 inhibitors, together with miR-3591-3p mimics, increased IL-6 mRNA levels in THP-1 cells in response to LPS stimulation.

Conclusions

We observed differential expression of microRNAs associated with increased production of IL-6 in BD patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12950-016-0130-7) contains supplementary material, which is available to authorized users.

Vascular Remodelling and Mesenchymal Transition in Systemic Sclerosis

Fibrosis of the skin and of internal organs, autoimmunity, and vascular inflammation are hallmarks of Systemic Sclerosis (SSc). The injury and activation of endothelial cells, with hyperplasia of the intima and eventual obliteration of the vascular lumen, are early features of SSc. Reduced capillary blood flow coupled with deficient angiogenesis leads to chronic hypoxia and tissue ischemia, enforcing a positive feed-forward loop sustaining vascular remodelling, further exacerbated by extracellular matrix accumulation due to fibrosis. Despite numerous developments and a growing number of controlled clinical trials no treatment has been shown so far to alter SSc natural history, outlining the need of further investigation in the molecular pathways involved in the pathogenesis of the disease. We review some processes potentially involved in SSc vasculopathy, with attention to the possible effect of sustained vascular inflammation on the plasticity of vascular cells. Specifically we focus on mesenchymal transition, a key phenomenon in the cardiac and vascular development as well as in the remodelling of injured vessels. Recent work supports the role of transforming growth factor-beta, Wnt, and Notch signaling in these processes. Importantly, endothelial-mesenchymal transition may be reversible, possibly offering novel cues for treatment.

MicroRNA-10a Regulation of Proinflammatory Mediators: An Important Component of Untreated Juvenile Dermatomyositis

Objective.

To identify differentially expressed microRNA (miRNA) in muscle biopsies (MBx) from 15 untreated children with juvenile dermatomyositis (JDM) compared with 5 controls.

Methods.

Following MBx miRNA profiling, differentially expressed miRNA and their protein targets were validated by quantitative real-time PCR (qRT-PCR) and immunological assay. The association of miRNA-10a and miRNA-10b with clinical data was evaluated, including Disease Activity Score (DAS), von Willebrand factor antigen (vWF:Ag), nailfold capillary end row loops, duration of untreated disease, and tumor necrosis factor (TNF)-α-308A allele.

Results.

In JDM, 16/362 miRNA were significantly differentially expressed [false discovery rate (FDR) < 0.05]. Among these, miRNA-10a was the most downregulated miRNA in both FDR and ranking of fold change: miRNA-10a = −2.27-fold, miRNA-10b = −1.80-fold. Decreased miRNA-10a and miRNA-10b expressions were confirmed using qRT-PCR: −4.16 and −2.59 fold, respectively. The qRT-PCR documented that decreased miRNA-10a expression was related to increased vascular cell adhesion molecule 1 in 13 of these JDM cases (correlation −0.67, p = 0.012), unlike miRNA-10b data (not significant). Concurrent JDM plasma contained increased levels of interleukin (IL) 6 (p = 0.0363), IL-8 (p = 0.0005), TNF-α (p = 0.0011), and monocyte chemoattractant proteins 1 (p = 0.0139). Decreased miRNA-10a, but not miRNA-10b, was associated with the TNF-α-308A allele (p = 0.015). In the 15 JDM, a trend of association of miRNA-10a (but not miRNA-10b) with vWF:Ag and DAS was observed.

Conclusion.

MiRNA-10a downregulation is an important element in untreated JDM muscle pathophysiology. We speculate that muscle miRNA expression in adult dermatomyositis differs from muscle miRNA expression in untreated childhood JDM.

Circulating Extracellular microRNA in Systemic Autoimmunity

MicroRNAs (miRNAs) are differentially regulated in healthy, activated, inflamed, neoplastic, or otherwise pathological cells and tissues. While their main functions are executed intracellularly, many miRNAs can reproducibly be detected extracellularly in plasma and serum. This circulating, extracellular miRNA is protected against degradation by complexation with carrier proteins and/or by being enclosed in subcellular membrane vesicles. This, together with their tissue- and disease-specific expression, has fuelled the interest in using circulating microRNA profiles as harbingers of disease, i.e., as diagnostic analytes and as clues to dysregulated pathways in disease. Many studies show that inflammation and immune dysregulation, e.g., in autoimmune diseases, are associated with distinct miRNA expression changes in targeted tissues and in innate and adaptive immunity cells such as lymphocytes, natural killer cells, neutrophil granulocytes, and monocyte-macrophages. Exploratory studies (only validated in a few cases) also show that specific profiles of circulating miRNAs are associated with different systemic autoimmune diseases including systemic lupus erythematosus (SLE), systemic sclerosis, and rheumatoid arthritis. Even though the link between cellular alterations and extracellular profiles is still unpredictable, the data suggest that circulating miRNAs in autoimmunity may become diagnostically useful. Here, we review important circulating miRNAs in animal models of inflammation and in systemic autoimmunity and summarize some proposed functions of miRNAs in immune regulation and dysregulation. We conclude that the studies suggest new hypotheses and additional experiments, and that further diagnostic development is highly dependent on analytical method development and on obtaining sufficient numbers of uniformly processed samples from clinically well-characterized patients and controls.

An Exploration of the Role of MicroRNAs in Psoriasis: A Systematic Review of the Literature

Psoriasis is recently characterized by a specific microRNAs (miRNAs) expression profile, which guides the researchers' efforts to explore the therapeutic targets and objective biomarkers that reflect the diagnosis and disease activity in clinical use for psoriasis.The paper presents a state-of-the-art review of expression and function of miRNAs in psoriasis along with its clinical implications.We analyzed all literature searched by keywords "microRNA" and "psoriasis" in PubMed (Medline) from inception up to July 2015, and the references in the literature searched were also considered.Relevant literature was chosen according to the objective of this review. Relevant literature was searched by 3 independent investigators, and experts in the field of miRNAs and psoriasis were involved in analyzing process.We included any study in which role of miRNAs in psoriasis was examined in relation to disease pathogenesis, diagnosis, and treatment.The specific miRNAs profile has been identified from human psoriatic skin, blood, and hair samples. It is found that genetic polymorphisms related to some of specific miRNAs, miR-146a for example, are associated with psoriasis susceptibility. Key roles of several unique miRNAs, such as miR-203 and miR-125b, in inflammatory responses and immune dysfunction, as well as hyperproliferative disorders of psoriatic lesions have been revealed. Moreover, circulating miRNAs detected from blood samples have a potential of clinic application to be the biomarkers of diagnosis, prognosis, and treatment responses. Additionally, a new layer of regulatory mechanisms mediated by miRNAs is to some extent revealed in pathogenesis of psoriasis.The dramatically altered mRNA expression profiles are displayed in psoriasis, and some of these may become disease markers and therapeutic targets. Herein, this work underscores the potential importance of miRNAs to diagnosis, prognosis, and treatment of psoriasis. However, further study in this field is worth doing in the future, as the exact roles of miRNAs in psoriasis have not been fully elucidated.Systematic review registration number is not registered.

MicroRNAs Regulating Signaling Pathways: Potential Biomarkers in Systemic Sclerosis

Systemic sclerosis (SSc) is a multisystem fibrotic and autoimmune disease. Both genetic and epigenetic elements mediate SSc pathophysiology. This review summarizes the role of one epigenetic element, known as microRNAs (miRNAs), involved in different signaling pathways of SSc pathogenesis. The expression of key components in transforming growth factor-β (TGF-β) signaling pathway has been found to be regulated by miRNAs both upstream and downstream of TGF-β. We are specifically interested in the pathway components upstream of TGF-β, while miRNAs in other signaling pathways have not been extensively studied. The emerging role of miRNAs in vasculopathy of SSc suggests a promising new direction for future investigation. Elucidation of the regulatory role of miRNAs in the expression of signaling factors may facilitate the discovery of novel biomarkers in SSc and improve the understanding and treatment of this disease.

MicroRNAs in pediatric central nervous system embryonal neoplasms: the known unknown

MicroRNAs (miRNAs) are endogenous short non-coding RNAs that repress post-transcriptional regulation of gene expression, while embryonal central nervous system tumors are the foremost cause of mortality in children suffering from a neoplasm. MiRNAs and their regulatory mechanisms are new to understand, while pediatric CNS tumors are difficult to comprehend. Therefore, identification of the link between them composes a major scientific challenge. The present study, reviewed the current knowledge on the role of miRNA in pediatric CNS embryonal tumors, attempting to collect the existing information in one piece of work that could ideally be used as a guide for future reference and research.