MicroRNA-20a-5p suppresses IL-17 production by targeting OSM and CCL1 in patients with Vogt-Koyanagi-Harada disease

Approaches based on miRNAs in Behçet's Disease: Unveiling pathogenic mechanisms, diagnostic strategies, and therapeutic applications

Behçet's Disease (BD) is an intricate medical puzzle, captivating researchers with its enigmatic pathogenesis. This complex ailment, distinguished by recurrent mouth and genital lesions, eye irritation, and skin injuries, presents a substantial obstacle to therapeutic research. This review explores the complex interaction of microRNAs (miRNAs) with BD, highlighting their crucial involvement in the disease's pathophysiology. miRNAs, recognized for regulatory influence in diverse biological processes, hold a pivotal position in the molecular mechanisms of autoimmune diseases, such as BD. The exploration begins with examining miRNA biogenic pathways and functions, establishing a foundational understanding of their regulatory mechanisms. Shifting to the molecular landscape governing BD, the review highlights miRNA-mediated impacts on critical signaling pathways like Notch, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and protein kinase B (AKT)/mammalian target of rapamycin (mTOR), offering insights into intricate pathophysiological mechanisms. Dissecting the immunological landscape reveals the profound influence of miRNAs on BD, shedding light on the intricate modulation of immune responses and offering novel perspectives on disease etiology and progression. Beyond molecular intricacies, the review explores the clinical relevance of miRNAs in BD, emphasizing their potential as diagnostic and prognostic indicators. The discussion extends to the promising realm of miRNA-based therapeutic interventions, highlighting their potential in alleviating symptoms and altering disease progression. This comprehensive review, serving as a valuable resource for researchers, clinicians, and stakeholders, aims to decipher the intricate molecular tapestry of BD and explore the therapeutic potential of miRNAs.

Involvement of interlukin-17A (IL-17A) gene polymorphism and interlukin-23 (IL-23) level in the development of peri-implantitis

BACKGROUND

Dental implantation has been practiced since ancient times and has gone through several stages. Dentists use dental implants to support dental prostheses such as crowns, bridges, dentures, face prostheses, or as an orthodontic anchor. Thus, the purpose of this study is to detect the role of the immune-genetic variation of IL-17A and related inflammatory cytokine (IL-23) in the initiation and progress of peri implantitis.

MATERIAL AND METHODS

This cross-sectional study included 80 subjects (15 peri-implantitis patients, 35 successful implants, and 30 healthy controls); their mean age was (43.91 ± 11.33) years. Blood samples and Peri-implant sulcus fluid (PISF) were collected from all subjects (patients with peri-implantitis, successful implants, and healthy controls) attending the Department of Oral and Maxillofacial Surgery in the Dental College Teaching Hospital, Baghdad University, Baghdad, Iraq. The blood sample detects gene polymorphisms in interleukin-17A by a polymerase chain reaction (PCR). An enzyme-linked immunosorbent assay (ELISA) was carried out to estimate the Peri-implant sulcus fluid (PISF) levels of interleukin-23.

RESULT

The current study revealed an obvious significant elevation in the mean level of interleukin-23 in the peri-implantitis patient's group more than its level in the successful implant and control groups (P < 0.05). In addition, the result showed that A/A genotype is associated significantly with peri-implantitis OR (95%confidence interval) =6.9 (1.7121 to 27.4638) folds increase risk of peri-implantitis) (p = 0.0065), while G/A genotype had OR 4.9 (0.9539-24.9394) folds increased risk of peri-implantitis, (p = 0.0572). But it was not statistically significant and G/G genotype had a one-fold increase risk of peri-implantitis.

CONCLUSION

The increased level of inflammatory cytokine (interleukin-23) might add to the systemic inflammatory burden a predisposing factor, which may lead to impaired osseointegration and subsequent bone loss or implant failure. In addition, IL-17A gene polymorphism may play a role in peri-implant disease susceptibility, especially in persons carrying the rs2275913 A allele at a higher risk of developing peri-implantitits as compared with those carrying the G allele.

Plasma-Derived Small Extracellular Vesicles From VKH Patients Suppress T Cell Proliferation Via MicroRNA-410-3p Modulation of CXCL5 Axis

Purpose

Circulating exosomes regulate immune responses and induce immune tolerance in immune-mediated diseases. This study aimed to investigate the role of circulating small extracellular vesicles (sEVs) derived from patients with Vogt-Koyanagi-Harada (VKH) syndrome, in T-cell responses.

Methods

The sEVs were isolated from the plasma of healthy controls, patients with VKH, and other uveitis patients. The effects of autologous and allogeneic sEVs on the proliferation of circulating CD4+ T cells were evaluated. Microarray analysis of sEVs was performed to determine their differential miRNA expression profiles. The target genes of the candidate miRNA were predicted and verified. The role of both the candidate miRNA and target genes in T-cell proliferation was tested.

Results

Plasma-derived sEVs from patients with VKH inhibited the proliferation of autologous CD4+ T cells. Among all the miRNAs that might be associated with inflammatory activity, we found that miR-410-3p had the largest number of T-cell proliferation target genes. MiR-410-3p mimics inhibited the proliferation of Jurkat cells and CD4+ T cells. C-X-C motif chemokine ligand 5 (CXCL5) was confirmed to be a potential target gene of miR-410-3p, and siRNA-mediated CXCL5 knockdown inhibited cell proliferation.

Conclusions

Circulating sEVs exert an inhibitory effect on autologous CD4+ T cells mediated by miR-410-3p by targeting CXCL5, supporting the possibility of using autogenic sEVs to inhibit ocular inflammation.

MicroRNAs in the regulation of Th17/Treg homeostasis and their potential role in uveitis

Th17 and regulatory T cells (Tregs) play crucial roles in the pathogenesis of autoimmune diseases. Th17/Treg homeostasis is critically involved in maintaining the immune balance. Disturbed Th17/Treg homeostasis contributes to the progression of autoimmune diseases. MicroRNAs (miRNAs) have emerged as a new vital factor in the regulation of disturbed Th17/Treg homeostasis. To better understand the epigenetic mechanisms of miRNAs in regulating Treg/Th17 homeostasis, we included and evaluated 97 articles about autoimmune diseases and found that miRNAs were involved in the regulation of Treg/Th17 homeostasis from several aspects positively or negatively, including Treg differentiation and development, Treg induction, Treg stability, Th17 differentiation, and Treg function. Uveitis is one of the ocular autoimmune diseases, which is also characterized with Th17/Treg imbalance. However, our understanding of the miRNAs in the pathogenesis of uveitis is elusive and not well-studied. In this review, we further summarized miRNAs found to be involved in autoimmune uveitis and their potential role in the regulation of Th17/Treg homeostasis.

Concentration of Serum Biomarkers of Brain Injury in Neonates With a Low Cord pH With or Without Mild Hypoxic-Ischemic Encephalopathy

Objective

To determine the concentrations of four neuroprotein biomarkers and 68 miRNAs in neonates with low cord pH and/or mild hypoxic-ischemic encephalopathy (HIE).

Study Design

A prospective cohort study enrolled neonates with low cord pH (n = 18), moderate-severe HIE (n = 40), and healthy controls (n = 38). Groups provided serum samples at 0–6 h of life. The concentrations of biomarkers and miRNAs were compared between cohorts.

Result

The low cord pH and moderate-severe HIE groups had increased concentrations of GFAP, NFL and Tau compared to controls (P < 0.05, P < 0.001, respectively). NFL concentrations in mild HIE was higher than controls (P < 0.05) but less than moderate-severe HIE (P < 0.001). Of 68 miRNAs, 36 in low cord pH group and 40 in moderate-severe HIE were upregulated compared to controls (P < 0.05). Five miRNAs in low cord pH group (P < 0.05) and 3 in moderate-severe HIE were downregulated compared to controls (P < 0.05).

Conclusion

A biomarker panel in neonates with low cord pH may help clinicians make real-time decisions.

Circulating microRNA sequencing revealed miRNome patterns in hematology and oncology patients aiding the prognosis of invasive aspergillosis

Invasive aspergillosis (IA) may occur as a serious complication of hematological malignancy. Delays in antifungal therapy can lead to an invasive disease resulting in high mortality. Currently, there are no well-established blood circulating microRNA biomarkers or laboratory tests which can be used to diagnose IA. Therefore, we aimed to define dysregulated miRNAs in hematology and oncology (HO) patients to identify biomarkers predisposing disease. We performed an in-depth analysis of high-throughput small transcriptome sequencing data obtained from the whole blood samples of our study cohort of 50 participants including 26 high-risk HO patients and 24 controls. By integrating in silico bioinformatic analyses of small noncoding RNA data, 57 miRNAs exhibiting significant expression differences (P < 0.05) were identified between IA-infected patients and non-IA HO patients. Among these, we found 36 differentially expressed miRNAs (DEMs) irrespective of HO malignancy. Of the top ranked DEMs, we found 14 significantly deregulated miRNAs, whose expression levels were successfully quantified by qRT-PCR. MiRNA target prediction revealed the involvement of IA related miRNAs in the biological pathways of tumorigenesis, the cell cycle, the immune response, cell differentiation and apoptosis.

The emerging role of epigenetics and gut microbiota in Vogt-Koyanagi-Harada syndrome

Vogt-Koyanagi-Harada (VKH) syndrome is an autoimmune disorder characterized often by acute diffuse uveitis, also known as idiopathic uveoencephalitis. The associated complications can potentially affect multiple systems throughout the body, including eyes, ears, skin and nervous system. Although the pathogenesis of VKH syndrome remains unclear, it has been established that the various genetic factors, epigenetic factors and the imbalance in immune regulation can significantly contribute to the development of this disease. In addition, the experimental autoimmune uveitis (EAU) has been commonly used to further explore the pathogenesis of the disease. Herein, in this review article, we discuss about the major research advances made in understanding of the different epigenetic factors and gut microbes involved in the pathogenesis of VKH syndrome as well as EAU. The information discussed can help to better understand the pathogenesis of VKH syndrome, and thereby might provide a basis for finding novel molecular targets and innovative treatment strategies in the future.

Epigenetic Modifications and Therapy in Uveitis

Uveitis is a sight-threatening intraocular inflammation, and the exact pathogenesis of uveitis is not yet clear. Recent studies, including multiple genome-wide association studies (GWASs), have identified genetic variations associated with the onset and progression of different types of uveitis, such as Vogt–Koyanagi–Harada (VKH) disease and Behcet’s disease (BD). However, epigenetic regulation has been shown to play key roles in the immunoregulation of uveitis, and epigenetic therapies are promising treatments for intraocular inflammation. In this review, we summarize recent advances in identifying epigenetic programs that cooperate with the physiology of intraocular immune responses and the pathology of intraocular inflammation. These attempts to understand the epigenetic mechanisms of uveitis may provide hope for the future development of epigenetic therapies for these devastating intraocular inflammatory conditions.

MiRNAs as New Tools in Lesion Vitality Evaluation: A Systematic Review and Their Forensic Applications

Wound vitality demonstration is one of the most challenging fields in forensic pathology. In recent years, researchers focused on the application of histological and immunohistochemical staining in this sphere of study. It is based on the detection of inflammation, red cell infiltration, and tissue alterations at the histological examination, all of which are supposedly present in antemortem rather than post-mortem wounds. Nevertheless, some doubts about the reliability of those markers have arisen. Furthermore, the lack of a standardized protocol and the operator dependency of this approach make the proper interpretation of its results difficult. Moreover, a differential miRNAs expression has been demonstrated in antemortem and post-mortem wounds. Herein, a systematic review concerning the current knowledge about the use of miRNAs in lesion vitality evaluation is carried out, to encourage researchers to deepen this peculiar study area. A compendium about the potential miRNAs that may be further investigated as vitality markers is also provided. The aim is to collect all available data about this topic to direct further studies on this field and highlight the future applications of miRNAs in forensic pathology. We found 20 articles and a total of 51 miRNAs that are involved in inflammation and wound healing. Further studies are certainly needed to deepen the role of miRNAs in inflammatory processes in lesioned skin and to evaluate their reliability in distinguishing between antemortem and post-mortem lesions.

Research Progress on the Mechanism of Natural Product Ingredients in the Treatment of Uveitis

Background

As the spectrum of ophthalmic diseases keeps changing, uveitis has gradually become one of the major blinding eye diseases in the world. In recent years, it has become a research hotspot to select effective components for uveitis treatment from natural drugs.

Methods

We searched PubMed and EMBASE databases for studies written in English as well as Chinese National Knowledge Infrastructure (CNKI), CQVIP, and Wan Fang database for studies written in Chinese (inception through 30 December 2020).

Results

Eight kinds of natural product ingredients were included in this article. They were found to not only regulate the expression of cytokines, proliferation, and differentiation of T help cells but also inhibit the damage of cytokines and inflammatory cells to uvea, blood aqueous barrier, and blood retinal barrier.

Conclusion

Natural product ingredients have their unique advantages in the treatment of uveitis. They have good anti-inflammatory effects without causing serious adverse reactions, which enables them to be promising choices for preventive and therapeutic strategy of uveitis.

miR-20a Overexpression in Adipose-Derived Mesenchymal Stem Cells Promotes Therapeutic Efficacy in Murine Lupus Nephritis by Regulating Autophagy

Objective

Lupus nephritis is the most common and severe complication of systemic lupus erythematosus. The aim of our study was to investigate the efficacy of miR-20a overexpressing adipose-derived stem cell (ADSC) transplantation in murine lupus nephritis (LN) and explore potential molecular mechanisms.

Methods

Mouse ADSCs were transfected with a miR-20a lentiviral vector to obtain miR-20a overexpression ADSCs (miR-20a-ADSCs). We first observed the influence of miR-20a on ADSC viability and apoptosis in vitro. B6.MRL/lpr mice were administered ADSC/miR-20a-ADSC intravenously every week from age 30 to 33 weeks, and the lupus and normal control groups received PBS on the same schedule.

Results

miR-20a expression increased in miR-20a-ADSC-derived exosomes, and miR-20a overexpression promoted ADSC proliferation and inhibited apoptosis. Compared with ADSCs, miR-20a-ADSC treatment significantly improved serologic and histologic abnormalities, as evidenced by reduced serum creatinine, anti-dsDNA antibody, 24 h urine protein levels, nephritis scores, and C3/IgG deposits. Furthermore, miR-20a-ADSC treatment resulted in downregulated Akt, mTOR, and p62 expression and upregulated miR-20a, Beclin 1, and LC3 II/I expression compared with ADSC treatment. After treatment with miR-20a-ADSC, a significant increase in the number of autophagosomes within podocytes was observed, along with upregulated expression of podocin and nephrin, compared with the ADSC group.

Conclusions

miR-20a-ADSC transplantation prevents the development of lupus nephritis and significantly ameliorates already-established disease, and its mechanism is related to autophagy by targeting the miR-20a-regulated mTOR pathway.

miR-20a suppresses Treg differentiation by targeting Map3k9 in experimental autoimmune encephalomyelitis

Background

Experimental autoimmune encephalomyelitis (EAE) is a model for inflammatory demyelinating diseases of the central nervous system (CNS), a group of autoimmune diseases characterized by inflammatory infiltration, demyelination, and axonal damage. miR-20a is dysregulated in patients with CNS inflammatory demyelinating diseases; however, the function of miR-20a remains unclear. In this study, we intended to explore the role of miR-20a in EAE.

Methods

The expression of miR-20a was detected by quantitative real-time PCR (qRT-PCR) in EAE mice and patients with MOG antibody-associated demyelinating diseases. CD4⁺ T cells of EAE mice were sorted, stimulated, and polarized with miR-20a knockdown. Activation and differentiation of CD4⁺ T cells were analyzed by flow cytometry. The expression of target gene Map3k9 was detected by qRT-PCR and western blot experiments. The binding of miR-20a to the 3’ UTR of Map3k9 was tested by luciferase assays. The feasibility of miR-20a as a therapeutic target to alleviate the severity of EAE was explored by intravenous administration of miR-20a antagomirs to EAE mice.

Results

miR-20a was upregulated in splenocytes and lymph node cells, CD4⁺ T cells, and spinal cords of EAE mice. Moreover, miR-20a knockdown did not influence the activation of antigen-specific CD4⁺ T cells but promoted their differentiation into Treg cells. Map3k9 was predicted to be a target gene of miR-20a. The expressions of Map3k9 and miR-20a were negatively correlated, and miR-20a knockdown increased the expression of Map3k9. In addition, miR-20a binded to the 3’ UTR of Map3k9, and simultaneous knockdown of miR-20a and Map3k9 counteracted the enhanced differentiation of Tregs observed when miR-20a was knocked down alone. Furthermore, injection of miR-20a antagomirs to EAE mice reduced the severity of the disease and increased the proportion of Treg cells in peripheral immune organs.

Conclusions

miR-20a suppresses the differentiation of antigen-specific CD4⁺ T cells into Tregs in EAE by decreasing the expression of Map3k9. miR-20a antagomirs alleviate EAE, suggesting a new therapy for EAE and CNS inflammatory demyelinating diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02893-4.

miRNA Landscape in Pathogenesis and Treatment of Vogt-Koyanagi-Harada Disease

miRNAs, one of the members of the noncoding RNA family, are regulators of gene expression in inflammatory and autoimmune diseases. Changes in miRNA pool expression have been associated with differentiation of CD4⁺ T cells toward an inflammatory phenotype and with loss of self-tolerance in autoimmune diseases. Vogt–Koyanagi–Harada (VKH) disease is a chronic multisystemic pathology, affecting the uvea, inner ear, central nervous system, and skin. Several lines of evidence support an autoimmune etiology for VKH, with loss of tolerance against retinal pigmented epithelium-related self-antigens. This deleterious reaction is characterized by exacerbated inflammation, due to an aberrant T_H1 and T_H17 polarization and secretion of their proinflammatory hallmark cytokines interleukin 6 (IL-6), IL-17, interferon γ, and tumor necrosis factor α, and an impaired CD4⁺ CD25^high FoxP3⁺ regulatory T cell function. To restrain inflammation, VKH is pharmacologically treated with corticosteroids and immunosuppressive drugs as first and second line of therapy, respectively. Changes in the expression of miRNAs related to immunoregulatory pathways have been associated with VKH development, whereas some genetic variants of miRNAs have been found to be risk modifiers of VKH. Furthermore, the drugs commonly used in VKH treatment have great influence on miRNA expression, including those miRNAs associated to VKH disease. This relationship between response to therapy and miRNA regulation suggests that these small noncoding molecules might be therapeutic targets for the development of more effective and specific pharmacological therapy for VKH. In this review, we discuss the latest evidence regarding regulation and alteration of miRNA associated with VKH disease and its treatment.

Comprehensive miRNA Analysis Using Serum From Patients With Noninfectious Uveitis

Purpose

MicroRNAs (miRNAs) are noncoding RNAs and have attracted attention as a biomarker in a variety of diseases. However, extensive unbiased miRNAs analysis in patients with uveitis has not been completely explored. In the present study, we comprehensively analyzed the deregulated miRNAs in three major forms of uveitis (Behҫet's disease [BD], sarcoidosis and Vogt–Koyanagi–Harada disease [VKH]) to search for potential biomarkers.

Methods

This study included 10 patients with BD, 17 patients with sarcoidosis, and 13 patients with VKH. Eleven healthy subjects were used as controls. The miRNAs expression levels were studied by microarray using serum samples from patients with uveitis and healthy controls.

Results

A total of 281 upregulated miRNAs and 137 downregulated miRNAs were detected in patients with BD, 35 upregulated miRNAs and 86 downregulated miRNAs in patients with sarcoidosis, and 153 upregulated miRNAs and 35 downregulated miRNAs in patients with VKH. Some deregulated miRNAs were involved in the mitogen-activated protein kinase signaling pathway and inflammatory cytokine pathways. Furthermore, we identified miR-4708-3p, miR-4323, and let-7g-3p as the best predictor miRNAs for BD, sarcoidosis, and VKH, respectively. Panels of miRNAs with diagnostic potential for the three diseases were generated using machine learning.

Conclusions

In this study, comprehensive miRNA analysis identified deregulated miRNAs in three major forms of noninfectious uveitis. This study provides new insights into molecular pathogenetic mechanisms and useful information toward developing novel diagnostic biomarkers and therapeutic targets for BD, sarcoidosis, and VKH.

High Ambient Temperature Aggravates Experimental Autoimmune Uveitis Symptoms

Whether ambient temperature influences immune responses leading to uveitis is unknown. We thus tested whether ambient temperature affects the symptoms of experimental autoimmune uveitis (EAU) in mice and investigated possible mechanisms. C57BL/6 mice were kept at a normal (22°C) or high temperature (30°C) housing conditions for 2 weeks and were then immunized with human interphotoreceptor retinoid-binding protein (IRBP651–670) peptide to induce EAU. Histological changes were monitored to evaluate the severity of uveitis. Frequency of Th1 cells and Th17 cells was measured by flow cytometry (FCM). The expression of IFN-γ and IL-17A mRNA was measured by real-time qPCR. The generation of neutrophil extracellular traps (NETs) was quantified by enzyme-linked immunosorbent assay (ELISA). Differential metabolites in the plasma of the mice kept in the aforementioned two ambient temperatures were measured via ultra-high-performance liquid chromatography triple quadrupole mass spectrometry quadrupole time of flight mass spectrometry (UHPLC-QQQ/MS). The differential metabolites identified were used to evaluate their effects on differentiation of Th1 and Th17 cells and generation of NETs in vitro. The results showed that EAU mice kept at high temperature experienced a more severe histopathological manifestation of uveitis than mice kept at a normal temperature. A significantly increased frequency of Th1 and Th17 cells in association with an upregulated expression of IFN-γ and IL-17A mRNA was observed in the splenic lymphocytes and retinas of EAU mice in high temperature. The expression of NETs as evidenced by myeloperoxidase (MPO) and neutrophil elastase (NE), was significantly elevated in serum and supernatants of neutrophils from EAU mice kept at high temperature compared to the normal temperature group. The metabolites in the plasma from EAU mice, fumaric acid and succinic acid, were markedly increased in the high temperature group and could induce the generation of NETs via the NADPH oxidase-dependent pathway, but did not influence the frequency of Th1 and Th17 cells. Our findings suggest that an increased ambient temperature is a risk factor for the development of uveitis. This is associated with the induction of Th1 and Th17 cells as well as the generation of NETs which could be mediated by the NADPH oxidase-dependent pathway.

Human Adipose-Derived Mesenchymal Stem Cells-Derived Exosomal microRNA-19b Promotes the Healing of Skin Wounds Through Modulation of the CCL1/TGF-β Signaling Axis

Introduction

Human adipose-derived mesenchymal stem cells (ADMSCs) with their secretory factors are able to induce collagen synthesis and fibroblast migration in the wound healing process. This study is launched to figure out the effect of human ADMSCs-derived exosomes on skin wound healing.

Methods

ADMSCs were extracted and ADMSCs-derived exosomes were identified. Skin damage models were established by treating HaCaT cells and human skin fibroblasts with H₂O₂. Next, the roles of ADMSCs and their derived exosomes were investigated. The exosomal miRNA then was analyzed, and the function of miRNA on the H₂O₂-induced cells was studied by miRNA suppression. Bioinformatics analysis, luciferase activity and RIP assays were implemented to find the target genes ofthe miRNA and the modulated pathways. A mouse skin damage model was induced to elucidate the effects of exosomes in vivo by injecting exosomes.

Results

H₂O₂ treatment significantly reduced the viability of HaCaT cells and increased their apoptosis rate. Co-culture with ADMSCs or their derived exosomes could improve the cell damage caused by H₂O₂. Meanwhile, H₂O₂ treatment promoted the internalization of exosomes. ADMSCs and their derived exosomes significantly increased miR-19b expression in the recipient cells, while inhibiting miR-19b resulted in a reduction in the therapeutic effect of ADMSCs-derived exosomes. Besides, miR-19b regulated the TGF-β pathway by targeting CCL1. The therapeutic effect of exosomes was further confirmed by a mouse model of skin damage.

Conclusion

Our study indicates that exosomal miR-19b derived from ADMSCs regulates the TGF-β pathway by targeting CCL1, thereby promoting the healing of skin wounds.

Genetic variations in autoimmune genes and VKH disease

PURPOSE

Vogt-Koyanagi-Harada (VKH) disease is a rare autoimmune disease. The autoimmune response in VKH disease is against the melanin-producing cells; therefore, in affected individuals melanocyte-containing organs manifest disease symptoms including eyes, ears, skin and nervous system. VKH is a multifactorial disease, and the precise cause of the VKH disease is unknown. Studies have suggested that both environmental and genetic factors are responsible for the VKH disease. In this review, the authors have collected all the available literature on the genetics of VKH to their knowledge and discussed the role of genetic variants in causing VKH disease.

METHODS

An extensive literature search was performed in order to review all the published studies regarding VKH clinical phenotyping and genetic variants in VKH disease. Medline, PubMed, Cochrane library, and Scopus was searched using combination of keywords.

RESULTS

It was found that variants in HLA genes, IL-12b, TNFSF4, and miR-20-5p genes are significantly associated with VKH; however, variants in genes ATG10, TNIP1 and CLEC16A did not achieve significant genome-wide association threshold. Moreover, polymorphisms in TNIP1 and CLEC16A play a protective role against VKH.

CONCLUSION

The authors conclude that increased sample size and a more homogeneous VKH patient population may reveal a significant association of variants in ATG10, TNIP1 and CLEC16A genes with VKH disease.

MicroRNAs and Autoimmune-Mediated Eye Diseases

MicroRNAs (miRNAs) are evolutionarily conserved short non-coding RNAs that act at post-transcriptional regulation of gene expression by destroying target messenger RNA or inhibiting its translation. Recently, miRNAs have been identified as important regulators in autoimmunity. Aberrant expression and function of miRNAs can lead to dysfunction of immune system and mediate autoimmune disorders. Here, we summarize the roles of miRNAs that have been implicated in three representative ocular autoimmune disorders, including autoimmune uveitis, Grave's ophthalmopathy, and Sjögren's syndrome dry eye, and discuss the potential of miRNAs as biomarkers and therapeutic targets for the diagnosis and treatment of these diseases.

miR-182-5p inhibits the pathogenic Th17 response in experimental autoimmune uveitis mice via suppressing TAF15

BACKGROUND

CD4⁺ T helper 17 (Th17) cells play a contributory role in uveitis and other autoimmune disorders. However, less is understood about the contribution of microRNAs (miRNAs) in regulating the pathogenic Th17 response in uveitis.

METHODS

The in vivo experimental autoimmune uveitis (EAU) model was constructed in female C57BL/6 mice. Primary EAU mouse CD4⁺ T-cells and the murine T-cell line EL4 were used for in vitro experiments. miRNA mimic/inhibitor, lentiviral overexpression plasmids, and small interfering RNAs (siRNAs) were used to modulate miR-182-5p and TAF15 expression. CD4⁺ T-cells from healthy controls (HC, n = 15), active Behçet's disease with uveitis (BD, n = 15), or active sympathetic ophthalmia with uveitis (SO, n = 15) were analyzed for miR-182-5p, TAF15, and Th17 marker gene expression.

RESULTS

miR-182-5p was downregulated in EAU mouse-derived Th17 cells. miR-182-5p negatively regulated Th17 cell development in vitro. miR-182-5p mimic therapy in transplanted Th17 cells ameliorated EAU severity in vivo. Mechanistically, miR-182-5p directly inhibited the transcriptional initiator TATA-binding protein-associated factor 15 (TAF15, TAFII68). miR-182-5p's inhibition of TAF15 negatively regulated Th17 cell development by suppressing STAT3 phosphorylation. TAF15 and Th17 marker expression were positively correlated in CD4⁺ T-cells from BD and SO patients.

CONCLUSION

miR-182-5p mimic therapy inhibits the pathogenic Th17 response in EAU mice. miR-182-5p's inhibition of TAF15 negatively regulates Th17 cell development by suppressing STAT3 phosphorylation. As TAF15 shows a positive relationship with Th17 cell markers in uveitis patients, the miR-182-5p/TAF15 axis shows promise as a therapeutic target for uveitis.

Plasma metabolomics study of Vogt-Koyanagi-Harada disease identifies potential diagnostic biomarkers

Vogt-Koyanagi-Harada (VKH) disease is a common type of uveitis in China, but the diagnosis criteria of VKH disease is controversial. The aim of this study was to investigate potential diagnostic plasma biomarkers for VKH disease. A case-control study including 55 VKH patients (28 active patients and 27 inactive VKH patients) and 30 healthy controls in a tertiary referral center was performed. The metabolic phenotype of VKH patients showed a significant difference compared to healthy controls. Fifteen differentially expressed metabolites (DEMs) were identified between active VKH patients and healthy controls and nine DEMs were found between inactive VKH patients and healthy controls after controlling variable importance in the projection (VIP) value > 1 and false discovery rate (FDR) < 0.05. D-mannose, stearic acid and L-lysine were shown to be potential diagnostic biomarkers which can discriminate active VKH patients from healthy controls with a diagnostic performance with AUC = 0.965, 0.936 and 0.910 respectively in independent diagnosis and an AUC = 0.999 when combined. Sarcosine was recognized as an independent potential biomarker which could distinguish inactive VKH patients from healthy controls. This study reveals a significant difference of plasma metabolic phenotype and identifies diagnostic biomarkers for VKH disease. Changes in the metabolic profile may provide clues towards the pathophysiology of VKH disease.

Identification of Ribosomal Protein S4, Y-Linked 1 as a cyclosporin A plus corticosteroid resistance gene

Combination of corticosteroids (CS) with cyclosporin A (CsA) is widely used in the treatment of autoimmune diseases, autoinflammatory diseases and transplantation rejection. However, some patients fail to respond or develop resistance to the combination regimen. In Vogt-Koyanagi-Harada (VKH) disease model, we performed RNA sequencing (RNA-seq) based transcriptomics, isobaric tags for relative and absolute quantification (iTRAQ) based proteomics and assays in vitro to screen and validate potential resistant molecules. We found that a total of 1697 differentially expressed genes (DEGs) and 21 differentially expressed proteins (DEPs) in CD4⁺ T cells between CsA & CS-resistant and -sensitive VKH patients. Ribosomal Protein S4, Y-Linked 1 (RPS4Y1) was verified to regulate the resistance of CD4⁺ T cells from male VKH patients to CsA & CS. Importantly, we showed that chlorambucil (CLB) could reverse the resistance by RPS4Y1 suppression. Taken together, we identify RPS4Y1 as an important CsA & CS resistance gene in VKH disease. Researchers should consider validating the resistant effect of RPS4Y1 in other autoimmune diseases or organ transplantation.

miR-181b/Oncostatin m axis inhibits prostate cancer bone metastasis via modulating osteoclast differentiation

The activation of osteoblasts is significantly correlated to prostate tumor bone metastasis and bone loss. Oncostatin M (OSM) could promote breast cancer metastasis to bone. However, its role and mechanism in prostate cancer bone metastasis remain unclear. MicroRNAs (miRNAs) could play important roles in cancers via post-transcriptionally regulating target genes via binding to specific sequences in the 3' UTR of downstream target genes. In the present study, we performed microarray profiling analyses to identify differentially-expressed miRNAs in preosteoclast before and after osteoclast differentiation that could target OSM. miR-181b-5p was downregulated during Raw264.7 cells differentiation into osteoclast. By direct targeting OSM 3' UTR, miR-181b-5p inhibited OSM messenger RNA expression and protein levels, subsequently decreasing IL-6 and AREG and increasing OPG, while OSM overexpression exerted an opposing effect. More importantly, co-culture with miR-181b-5p-overexpressing differentiated Raw264.7 cells suppressed proliferation, migration, and invasion of mouse prostate cancer RM-1 cells, while co-culture with OSM-overexpressing Raw264.7 cells led to opposing cellular effects. More importantly, the effects of miR-181b-5p on osteoclastogenic factors and RM-1 cells could be significantly reversed by OSM overexpression. In summary, miR-181b-5p/OSM axis could be a viable therapeutic target for patients with surgically removed primary tumors to reduce bone metastasis and prevent bone loss.

miR-223-3p promotes autoreactive Th17 cell responses in experimental autoimmune uveitis (EAU) by inhibiting transcription factor FOXO3 expression

Pathogenic T helper (T_h)17 cells are key mediators of autoimmune diseases such as uveitis and its animal model, experimental autoimmune uveitis (EAU). However, the contribution of microRNAs (miRs) to the intrinsic control of pathogenic T_h17 cells in EAU remains largely unknown. Here, we have reported that miR-223-3p was significantly up-regulated in interphotoreceptor retinoid-binding protein-specific T_h17 cells, and its expression was enhanced by IL-23-signal transducer and activator of transcription 3 signaling. Knockdown of miR-223-3p decreased the pathogenicity of T_h17 cells in a T-cell transfer model of EAU. Mechanistic studies showed that miR-223-3p directly repressed the expression of forkhead box O3 (FOXO3), and FOXO3 negatively regulated pathogenic T_h17 cell responses partially via suppression of IL-23 receptor expression. Thus, our results reveal an important role for miR-223-3p in autoreactive T_h17 cell responses and suggest a potential therapeutic avenue for uveitis.-Wei, Y., Chen, S., Sun, D., Li, X., Wei, R., Li, X., Nian, H. miR-223-3p promotes autoreactive T_h17 cell responses in experimental autoimmune uveitis (EAU) by inhibiting transcription factor FOXO3 expression.

Identifying the culprits in neurological autoimmune diseases

The target organ of neurological autoimmune diseases (NADs) is the central or peripheral nervous system. Multiple sclerosis (MS) is the most common NAD, whereas Guillain-Barré syndrome (GBS), myasthenia gravis (MG), and neuromyelitis optica (NMO) are less common NADs, but the incidence of these diseases has increased exponentially in the last few years. The identification of a specific culprit in NADs is challenging since a myriad of triggering factors interplay with each other to cause an autoimmune response. Among the factors that have been associated with NADs are genetic susceptibility, epigenetic mechanisms, and environmental factors such as infection, microbiota, vitamins, etc. This review focuses on the most studied culprits as well as the mechanisms used by these to trigger NADs.

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Neurological autoimmune diseases are caused by a complex interaction between genes, environmental factors, and epigenetic deregulation.

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Infectious agents can cause an autoimmune reaction to myelin epitopes through molecular mimicry and/or bystander activation.

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Gut microbiota dysbiosis contributes to neurological autoimmune diseases.

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Smoking increases the risk of NADs through inflammatory signaling pathways, oxidative stress, and Th17 differentiation.

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Deficiency in vitamin D favors NAD development through direct damage to the central and peripheral nervous system.

Visfatin promotes the malignancy of human acute myeloid leukemia cells via regulation of IL-17

Understanding the mechanisms of malignancy in acute myeloid leukemia (AML) cell is important for the targeted treatment and drug development. We found that visfatin, a 52-kDa adipokine, can positively regulate the proliferation of AML cells. Targeted inhibition of visfatin via its specific siRNAs or inhibitor can suppress the proliferation of AML cells. Further, knockdown of visfatin can increase the doxorubicin (Dox) and cisplatin (CDDP) sensitivity of AML cells. Among the tested six cytokines, si-visfatin can decrease the expression of interleukin-17 (IL-17). Over expression of IL-17 can reverse si-visfatin suppressed cell proliferation and increased Dox sensitivity. The upregulation of IL-17 was also involved in visfatin induced activation of PI3K/Akt signals in AML cells. The inhibitor of PI3K/Akt can synergistically suppress the proliferation of HL60 cells which were transfected with si-visfatin. Knockdown of visfatin can increase the expression of miR-135a, which can bind to the 3'UTR of IL-17 and decrease its expression. The inhibitor of miR-135a can attenuate si-visfatin suppressed expression of IL-17 and proliferation of AML cells. Collectively, our data suggested that visfatin can increase the malignancy of AML cells via regulation of miR-135a/IL-17/PI3K/Akt signals.

Disabled-2 (DAB2) Overexpression Inhibits Monocyte-Derived Dendritic Cells' Function in Vogt-Koyanagi-Harada Disease

Purpose

Recent studies reported that the tumor suppressor disabled-2 (DAB2) is a negative regulator of immune function. In this study, we investigated the role of DAB2 in monocyte-derived dendritic cells (DCs) from Vogt-Koyanagi-Harada disease (VKH) patients.

Methods

The mRNA and protein levels of DAB2 were quantified by quantitative real-time PCR and Western blot. The Sequenom MassARRAY system was used to detect the promoter methylation level. An adenovirus carrying the DAB2 gene was transduced into immature DCs, isolated, and induced from active VKH patients. The surface markers of DCs, the frequency of T helper (Th) type 1 (Th1) and Th17 cells in CD4+T cells, which were cocultured with DCs, were tested by flow cytometry. ELISA was used to analyze the inflammatory cytokines produced by DC and CD4+T cell cocultures.

Results

The mRNA and protein expression levels of DAB2 in DCs obtained from active VKH patients were decreased, while the DAB2 promoter methylation level was marginally increased when compared with inactive VKH patients and normal controls. The expression of CD86 on DCs was significantly downregulated by DAB2 overexpression. The DC-related inflammatory factors IL-6 and TNF-α were also decreased. The frequency of Th1 and Th17 cells and their related cytokines were reduced significantly after coculture with DAB2 overexpressing DCs. DAB2 overexpression did not affect autophagy in DCs from VKH patients.

Conclusions

These results suggest that the decreased expression of DAB2 in DCs plays a role in the pathogenesis of VKH disease. DAB2 overexpression inhibits DC function, but this is not mediated via autophagy.

MiRNA as biomarker for uveitis - A systematic review of the literature

AIM

A systematic review of miRNA profiling studies in uveitis.

METHODS

Literature search strategy - Pubmed central central database, using miRNA/microRNA and intraocular inflammation/uveitis as keywords.

RESULTS

We found twenty publications regarding the experimental and clinical use of miRNA in uveitis, published between 2011 and 2018.

CONCLUSION

The publications regarding the role of miRNA in uveitis are very scarce, but provide some valuable information about the potential new mechanisms in uveitis. Some of the identified miRNAs in different uveitis entities could serve as a biomarker of intraocular inflammation. Possible candidate miRNAs could be let-7e, miRNA-1, miR-9-3, miR-20a-5p, miR-23a, mir-29a-3p, miR-140-5p, miR-143, miR-146a and miR-146a-5p, miR-155, miR-182 and miR-182-5p, miR-196a2, miR-205, miR-223-3p, miR-301a. MiR-146a, miR-146a-5p, miR-155, miR-182, miR-223-3p, have been found to be possibly associated with uveitis disease in both, human and animal species.

Conflicting Effects of Methylglyoxal and Potential Significance of miRNAs for Seizure Treatment

According to an update from the World Health Organization, approximately 50 million people worldwide suffer from epilepsy, and nearly one-third of these individuals are resistant to the currently available antiepileptic drugs, which has resulted in an insistent pursuit of novel strategies for seizure treatment. Recently, methylglyoxal (MG) was demonstrated to serve as a partial agonist of the gamma-aminobutyric acid type A (GABA_A) receptor and to play an inhibitory role in epileptic activities. However, MG is also a substrate in the generation of advanced glycation end products (AGEs) that function by activating the receptor of AGEs (RAGE). The AGE/RAGE axis is responsible for the transduction of inflammatory cascades and appears to be an adverse pathway in epilepsy. This study systematically reviewed the significance of GABAergic MG, glyoxalase I (GLO1; responsible for enzymatic catalysis of MG cleavage) and downstream RAGE signaling in epilepsy. This work also discussed the potential of miRNAs that target multiple mRNAs and introduced a preliminary scheme for screening and validating miRNA candidates with the goal of reconciling the conflicting effects of MG for the future development of seizure treatments.