Silencing of microRNA-21 in vivo ameliorates autoimmune splenomegaly in lupus mice

Development of a major histocompatibility complex class II conditional knockout mouse to study cell-specific and time-dependent adaptive immune responses in peripheral nerves

INTRODUCTION/AIMS

The precise relationship between molecular mimicry and tissue-specific autoimmunity is unknown. Major histocompatibility complex (MHC) class II antigen presenting cell-CD4+ T-cell receptor complex interactions are necessary for adaptive immunity. This study aimed to determine the role of endoneurial endothelial cell MHC class II in autoimmune polyneuropathy.

METHODS

Cryopreserved Guillain-Barré syndrome (GBS) patient sural nerve biopsies and sciatic nerves from the severe murine experimental autoimmune neuritis (sm-EAN) GBS model were studied. Cultured conditional ready MHC Class II antigen A-alpha chain (H2-Aa) embryonic stem cells were used to generate H2-Aaflox/+ C57BL/6 mice. Mice were backcrossed and intercrossed to the SJL background to generate H2-Aaflox/flox SJL mice, bred with hemizygous Tamoxifen-inducible von Willebrand factor Cre recombinase (vWF-iCre/+) SJL mice to generate H2-Aaflox/flox; vWF-iCre/+ mice to study microvascular endothelial cell adaptive immune responses. Sm-EAN was induced in Tamoxifen-treated H2-Aaflox/flox; vWF-iCre/+, H2-Aaflox/flox; +/+, H2-Aa+/+; vWF-iCre/+ and untreated H2-Aaflox/flox; vWF-iCre/+ adult female SJL mice. Neurobehavioral, electrophysiological and histopathological assessments were performed at predefined time points.

RESULTS

Endoneurial endothelial cell MHC class II expression was observed in normal and inflamed human and mouse peripheral nerves. Tamoxifen-treated H2-Aaflox/flox; vWF-iCre/+ mice were resistant to sm-EAN despite extensive MHC class II expression in lymphoid and non-lymphoid tissues.

DISCUSSION

A conditional MHC class II knockout mouse to study cell- and time-dependent adaptive immune responses in vivo was developed. Initial studies show microvascular endothelial cell MHC class II expression is necessary for peripheral nerve specific autoimmunity, as advocated by human in vitro adaptive immunity and ex vivo transplant rejection studies.

MiR-425-5p suppression of Crebzf regulates oocyte aging via chromatin modification

Female infertility due to declining oocyte quality with age remains a significant challenge for patients and physicians, despite extensive research efforts. Recent studies suggest that microRNAs (miRNAs), which respond to various stressors in the aging process, may provide a promising solution. With the approval of small RNA drugs for clinical use, miRNA-based treatment of oocyte aging appears to be a viable option. Through high-throughput sequencing, miR-425-5p was identified as the only miRNA elevated under natural aging and oxidative stress. Microinjection of inhibitors to inhibit miR-425-5p effectively improved compromised phenotypes of old oocytes in vitro. Further investigation revealed that Crebzf acts as a mediator of miR-425-5p's age-related functions in old oocytes. In vivo treatment with miR-425-5p antagomirs significantly improved impaired oocyte development in reproductively old females by targeting Crebzf. Single-cell RNA sequencing revealed that Crebzf plays a vital role in regulating mRNAs targeting histone H3, trimethylated lysine 4 (H3K4me3), a crucial marker for transcriptional silencing. Overexpression of miR-425-5p could hinder oocyte maturation by downregulating Crebzf expression and disrupting transcriptional regulation. Our findings provide new insights into the potential of miR-425-5p antagomirs as a treatment for female infertility and highlight an elegant mechanism by which miR-425-5p inhibition of Crebzf inhibits a developmental switch in GV oocytes by regulating a group of histone methyltransferase mRNAs.

Spleen-targeted delivery systems and strategies for spleen-related diseases

The spleen, body's largest secondary lymphoid organ, is also a vital hematopoietic and immunological organ. It is regarded as one of the most significant organs in humans. As more researchers recognize the functions of the spleen, clinical methods for treating splenic diseases and spleen-targeted drug delivery systems to improve the efficacy of spleen-related therapies have gradually developed. Many modification strategies (size, charge, ligand, protein corona) and hitchhiking strategies (erythrocytes, neutrophils) of nanoparticles (NPs) have shown a significant increase in spleen targeting efficiency. However, most of the targeted drug therapy strategies for the spleen are to enhance or inhibit the immune function of the spleen to achieve therapeutic effects, and there are few studies on spleen-related diseases. In this review, we not only provide a detailed summary of the design rules for spleen-targeted drug delivery systems in recent years, but also introduce common spleen diseases (splenic tumors, splenic injuries, and splenomegaly) with the hopes of generating more ideas for future spleen research.

MicroRNA-21a-5p inhibition alleviates systemic sclerosis by targeting STAT3 signaling

BACKGROUND

MicroRNA (miRNA)-21-5p participates in various biological processes, including cancer and autoimmune diseases. However, its role in the development of fibrosis in the in vivo model of systemic sclerosis (SSc) has not been reported. This study investigated the effects of miRNA-21a-5p overexpression and inhibition on SSc fibrosis using a bleomycin-induced SSc mouse model.

METHODS

A murine SSc model was induced by subcutaneously injecting 100 μg bleomycin dissolved in 0.9% NaCl into C57BL/6 mice daily for 5 weeks. On days 14, 21, and 28 from the start of bleomycin injection, 100 μg pre-miRNA-21a-5p or anti-miRNA-21a-5p in 1 mL saline was hydrodynamically injected into the mice. Fibrosis analysis was conducted in lung and skin tissues of SSc mice using hematoxylin and eosin as well as Masson's trichrome staining. Immunohistochemistry was used to examine the expression of inflammatory cytokines, phosphorylated signal transducer and activator of transcription-3 (STAT3) at Y705 or S727, and phosphatase and tensin homologue deleted on chromosome-10 (PTEN) in skin tissues of SSc mice.

RESULTS

MiRNA-21a-5p overexpression promoted lung fibrosis in bleomycin-induced SSc mice, inducing infiltration of cells expressing TNF-α, IL-1β, IL-6, or IL-17, along with STAT3 phosphorylated cells in the lesional skin. Conversely, anti-miRNA-21a-5p injection improved fibrosis in the lung and skin tissues of SSc mice, reducing the infiltration of cells secreting inflammatory cytokines in the skin tissue. In particular, it decreased STAT3-phosphorylated cell infiltration at Y705 and increased the infiltration of PTEN-expressing cells in the skin tissue of SSc mice.

CONCLUSION

MiRNA-21a-5p promotes fibrosis in an in vivo murine SSc model, suggesting that its inhibition may be a therapeutic strategy for improving fibrosis in SSc.

Hsa-miR-21-5p reflects synovitis and tenosynovitis components of musculoskeletal ultrasonography Seven-joint scores in rheumatoid arthritis disease and predicts the disease flare

Rheumatoid arthritis (RA) is characterized by progressive joint destruction with subsequent serious disability. Objective biomarkers of RA course progression are lacking, which necessitates the discovery of activity indicators and predictors of the disease outcome. Musculoskeletal Ultrasound Seven-joint Score (MSUS7) is proposed as a reliable technique to evaluate radiographic RA progression. Homo sapiens-microRNA-21-5p (hsa-miR-21-5p) plays an important role during joint remodeling and the pro-inflammatory process driving RA progression. We aimed to evaluate plasma hsa-miR-21-5p as a noninvasive RA activity biomarker and to investigate if hsa-miR-21-5p is linked to MSUS7 components in the context of RA activity. This cross-sectional study included 71 RA patients classified into inactive (n = 36) and active (n = 35) groups according to the Disease Activity Score 28-joint count with ESR (DAS28-ESR). Joints were assessed by MSUS7. Gray-scale ultrasound (GSUS) and power Doppler ultrasound (PDUS) were used to rate the synovitis, tenosynovitis, and erosion in the joints. Plasma hsa-miR-21-5p expression was measured by real-time PCR. The absolute count of regulatory T cell (Treg) was calculated after Treg frequency was assessed by flow cytometry. Results: Hsa-miR-21 expression was significantly up-regulated in the active RA group with a median fold change of 51.6 in comparison to the inactive cases with a median fold change of 7.7 (p < 0.001). Hsa-miR-21-5p was positively correlated with DAS28-ESR, C reactive protein (CRP), and rheumatoid factor (r = 0.7, p < 0.001, r = 0. 0.6, p < 0.001, and r = 0.4, p = 0.002, respectively), while negatively correlated with Treg absolute count (r = -0.4, p < 0.001). Hsa-miR-21-5p levels were correlated with synovitis and tenosynovitis in GSUS (r = 0.4, p < 0.001, r = 0.3, p = 0.025, respectively) and in PDUS (r = 0.5, p < 0.001 and 0.4, p = 0.001, respectively). The hsa-miR-21-5p accurately distinguished RA activity [AUC 0.933, 94.3% sensitivity, and 86.1% specificity]. Logistic regression analysis revealed hsa-miR-21-5p as an independent predictor for RA flare (OR = 1.228, p = 0.004). Hsa-miR-21-5p was linked to synovitis and tenosynovitis components of the MSUS7. Up-regulated hsa-miR-21-5p can be utilized as a predictor for RA disease flare.

Controlling viral inflammatory lesions by rebalancing immune response patterns

In this review, we discuss a variety of immune modulating approaches that could be used to counteract tissue-damaging viral immunoinflammatory lesions which typify many chronic viral infections. We make the point that in several viral infections the lesions can be largely the result of one or more aspects of the host response mediating the cell and tissue damage rather than the virus itself being directly responsible. However, within the reactive inflammatory lesions along with the pro-inflammatory participants there are also other aspects of the host response that may be acting to constrain the activity of the damaging components and are contributing to resolution. This scenario should provide the prospect of rebalancing the contributions of different host responses and hence diminish or even fully control the virus-induced lesions. We identify several aspects of the host reactions that influence the pattern of immune responsiveness and describe approaches that have been used successfully, mainly in model systems, to modulate the activity of damaging participants and which has led to lesion control. We emphasize examples where such therapies are, or could be, translated for practical use in the clinic to control inflammatory lesions caused by viral infections.

Development of a major histocompatibility complex class II conditional knockout mouse to study cell-specific and time-dependent adaptive immune responses in peripheral nerves

Introduction

Major histocompatibility complex (MHC) class II professional antigen presenting cell-naïve CD4+ T cell interactions via the T-cell receptor complex are necessary for adaptive immunity. MHC class II upregulation in multiple cell types occurs in human autoimmune polyneuropathy patient biopsies, necessitating studies to ascertain cellular signaling pathways required for tissue-specific autoimmunity.

Methods

Cryopreserved Guillain-Barré syndrome (GBS) patient sural nerve biopsies and sciatic nerves from the severe murine experimental autoimmune neuritis (sm-EAN) GBS model were studied. Cultured conditional ready MHC Class II antigen A-alpha chain (H2-Aa) embryonic stem cells were used to generate H2-Aa flox/+ C57BL/6 mice. Mice were backcrossed and intercrossed to the SJL background to generate H2-Aa flox/flox SJL mice, bred with hemizygous Tamoxifen-inducible von Willebrand factor Cre recombinase (vWF-iCre/+) SJL mice to generate H2-Aa flox/flox ; vWF-iCre/+ to study microvascular endothelial cell adaptive immune responses. Sm-EAN was induced in adult female SJL Tamoxifen-treated H2-Aa flox/flox ; vWF-iCre/+ mice and H2-Aa flox/flox ; +/+ littermate controls. Neurobehavioral, electrophysiological and histopathological assessments were performed at predefined time points.

Results

Endoneurial endothelial cell MHC class II expression was observed in normal and inflamed human and mouse peripheral nerves. Adult female Tamoxifen-treated H2-Aa flox/flox ; vWF-iCre/+ did not develop sm-EAN despite extensive MHC class II expression in lymphoid and non-lymphoid tissues.

Discussion

A conditional MHC class II knockout mouse to study cell- and time-dependent adaptive immune responses in vivo is developed. Initial studies show microvascular endothelial cell MHC class II expression is necessary for peripheral nerve specific autoimmunity, as advocated by human in vitro adaptive immunity and ex vivo transplant rejection studies.

Circulating miR-21 Overexpression Correlates with PDCD4 and IL-10 in Systemic Lupus Erythematosus (SLE): A Promising Diagnostic and Prognostic Biomarker

Background

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune condition that affects multiple organs significantly impacts morbidity and mortality. The development of SLE is influenced by genetic predisposition and dysregulated immune response. Our objective was to investigate miR-21, IL-10, and PDCD4 expression in SLE patient plasma and analyze their correlations and potential diagnostic and prognostic values.

Methods

The study included 100 healthy subjects, 50 newly diagnosed (ND), and 50 under-treatment (UT) SLE patients. The patients were observed for 24 weeks to track relapses. miR-21 and PDCD4 gene expression levels were measured using real-time RT-PCR, and IL-10 production was measured using ELISA.

Results

miR-21 and IL-10 expression levels were significantly greater in SLE patients than in healthy subjects, with the highest levels observed in ND patients. PDCD4 expression was also significantly greater in SLE patients than in subjects, with the highest levels observed in UT patients. ROC curve analyses and Cox-Mantel Log-rank tests indicated miR-21, PDCD4, and IL-10 as proper diagnostic and prognostic biomarkers for SLE. The study also revealed a significant positive correlation between miR-21 and PDCD4 and IL-10 levels in SLE patients.

Conclusions

The studies suggest that dysregulation of miR-21, PDCD4, and IL-10 in patients with SLE may contribute to disease development and provides new diagnostic and prognostic markers. Additionally, the observed correlation between miR-21, PDCD4, and IL-10 levels in SLE patients signifies a potential interplay between these molecules.

Systemic lupus erythematosus: From non-coding RNAs to exosomal non-coding RNAs

Systemic lupus erythematosus (SLE), as an immunological illness, frequently impacts young females. Both vulnerabilities to SLE and the course of the illness's clinical symptoms have been demonstrated to be affected by individual differences in non-coding RNA expression. Many non-coding RNAs (ncRNAs) are out of whack in patients with SLE. Because of the dysregulation of several ncRNAs in peripheral blood of patients suffering from SLE, these ncRNAs to be showed valuable as biomarkers for medication response, diagnosis, and activity. NcRNAs have also been demonstrated to influence immune cell activity and apoptosis. Altogether, these facts highlight the need of investigating the roles of both families of ncRNAs in the progress of SLE. Being aware of the significance of these transcripts perhaps elucidates the molecular pathogenesis of SLE and could open up promising avenues to create tailored treatments during this condition. In this review we summarized various non-coding RNAs and Exosomal non-coding RNAs in SLE.

MicroRNAs in autoimmune thyroid diseases and their role as biomarkers

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression at the posttranscriptional level. They are emerging as potential biomarkers and as therapeutic targets for several diseases including autoimmune thyroid diseases (AITD). They control a wide range of biological phenomena, including immune activation, apoptosis, differentiation and development, proliferation and metabolism. This function makes miRNAs attractive as disease biomarker candidates or even as therapeutic agents. Because of their stability and reproducibility circulating miRNAs have been an interesting area of research in many diseases, and studies describing their role in the immune response and in autoimmune diseases have progressively developed. The mechanisms underlying AITD remain elusive. AITD pathogenesis is characterized by a multifactorial interplay based on the synergy between susceptibility genes and environmental stimulation, together with epigenetic modulation. Understanding the regulatory role of miRNAs could lead to identify potential susceptibility pathways, diagnostic biomarkers and therapeutic targets for this disease. Herein we update our present knowledge on the role of microRNAs in AITD and discuss on their importance as possible diagnostic and prognostic biomarkers in the most prevalent AITDs: Hashimoto's thyroiditis (HT), Graves' disease (GD) and Graves' Ophthalmopathy (GO). This review provides an overview of the state of the art in the pathological roles of microRNAs as well as in possible novel miRNA-based therapeutic approaches in AITD.

Anti-seed PNAs targeting multiple oncomiRs for brain tumor therapy

Glioblastoma (GBM) is one of the most lethal malignancies with poor survival and high recurrence rates. Here, we aimed to simultaneously target oncomiRs 10b and 21, reported to drive GBM progression and invasiveness. We designed short (8-mer) γ-modified peptide nucleic acids (sγPNAs), targeting the seed region of oncomiRs 10b and 21. We entrapped these anti-miR sγPNAs in nanoparticles (NPs) formed from a block copolymer of poly(lactic acid) and hyperbranched polyglycerol (PLA-HPG). The surface of the NPs was functionalized with aldehydes to produce bioadhesive NPs (BNPs) with superior transfection efficiency and tropism for tumor cells. When combined with temozolomide, sγPNA BNPs administered via convection-enhanced delivery (CED) markedly increased the survival (>120 days) of two orthotopic (intracranial) mouse models of GBM. Hence, we established that BNPs loaded with anti-seed sγPNAs targeting multiple oncomiRs are a promising approach to improve the treatment of GBM, with a potential to personalize treatment based on tumor-specific oncomiRs.

Polyamines from myeloid-derived suppressor cells promote Th17 polarization and disease progression

Myeloid-derived suppressor cells (MDSCs) are a group of immature myeloid cells that play an important role in diseases. MDSCs promote Th17 differentiation and aggravate systemic lupus erythematosus (SLE) progression by producing arginase-1 to metabolize arginine. However, the metabolic regulators remain unknown. Here, we report that MDSC derivative polyamines can promote Th17 differentiation via miR-542-5p in vitro. Th17 polarization was enhanced in response to polyamine treatment or upon miR-542-5p overexpression. The TGF-β/SMAD3 pathway was shown to be involved in miR-542-5p-facilitated Th17 differentiation. Furthermore, miR-542-5p expression positively correlated with the levels of polyamine synthetases in peripheral blood mononuclear cells of patients with SLE as well as disease severity. In humanized SLE model mice, MDSC depletion decreased the levels of Th17 cells, accompanied by reduced expression of miR-542-5p and these polyamine synthetases. In addition, miR-542-5p expression positively correlated with the Th17 level and disease severity in both patients and humanized SLE mice. Together, our data reveal a novel molecular pathway by which MDSC-derived polyamine metabolism enhances Th17 differentiation and aggravates SLE.

Association between genetic variants of microRNA-21 and microRNA-155 and systemic lupus erythematosus: A case-control study from a Chinese population

Background

Systemic lupus erythematosus (SLE) is a common autoimmune disease, and its pathogenesis remains unclear. The alteration of genetic materials is believed to play a role in SLE development. This study evaluated the association between the genetic variants of microRNA‐21 (miR‐21) and microRNA‐155 (miR‐155) and SLE.

Methods

The SNaPshot genotyping method was used to detect the genotypes of selected SNPs in patients and controls. The expression of miR‐21 and miR‐155 was analyzed using reverse transcription‐quantitative polymerase chain reaction (RT‐qPCR). The functional annotation and the biological effects of SNPs were assessed by HaploReg V4.1 and Regulome DB V2.0 software. The Hardy–Weinberg equilibrium test was used to gather statistics, and odds ratios (ORs) and 95% confidence intervals (CIs) were evaluated by logistic regression.

Results

The distribution difference of TA genotype in rs767649 was observed (TA vs. T/T: OR = 0.68, 95%CI, 0.48–0.95, p = 0.026). There was a significant difference in the T/A + A/A (T/A + A/A vs. T/T: OR = 0.68, 95%CI, 0.49–0.94, p = 0.020). A significant difference in T allele distribution was found in the depressed complement of SLE (T vs. A: OR = 0.67, 95%CI, 0.47–0.95, p = 0.026). There were significant differences in genetic variants of rs13137 between the positive and the negative SSB antibodies (Anti‐SSB) (T vs. A: OR = 0.67, 95%CI, 0.47–0.95, p = 0.026; T/A + T/T vs. AA: OR = 2.23, 1.18–4.49, p = 0.013). The expression levels of miR‐21 and miR‐155 were significantly higher in patients than in controls (p < 0.001).

Conclusions

This study provides novel insight that genetic variants of rs767649 and rs13137 are associated with susceptibility to SLE.

Labile iron accumulation augments T follicular helper cell differentiation

T follicular helper (Tfh) cells are a subset of CD4⁺ T cells that are essential in the pathogenesis of systemic lupus erythematosus (SLE). Notably, iron is required for activated CD4⁺ T lymphocytes to sustain high proliferation and metabolism. In this issue of the JCI, Gao et al. showed that CD4⁺ T cells from patients with SLE accumulated iron, augmenting their differentiation into Tfh cells and correlating with disease activity. Using human cells and murine models, the authors demonstrated that miR-21 was overexpressed in lupus T cells and inhibited 3-hydroxybutyrate dehydrogenase-2 (BDH2). The subsequent loss of BDH2 drove labile iron to accumulate in the cytoplasm and promoted TET enzyme activity, BCL6 gene demethylation, and Tfh cell differentiation. This work identifies a role for iron in CD4⁺ T cell biology and the development of pathogenic effectors in SLE. We await future investigations that could determine whether modulating iron levels could regulate Tfh cells in human health and disease.

Identification and Contribution of Inflammation-Induced Novel MicroRNA in the Pathogenesis of Systemic Lupus Erythematosus

Recently microRNAs (miRNAs) have been recognized as powerful regulators of many genes and pathways involved in the pathogenesis of inflammatory diseases including Systemic Lupus Erythematosus (SLE). SLE is an autoimmune disease characterized by production of various autoantibodies, inflammatory immune cells, and dysregulation of epigenetic changes. Several candidate miRNAs regulating inflammation and autoimmunity in SLE are described. In this study, we found significant increases in the expression of miR21, miR25, and miR186 in peripheral blood mononuclear cells (PBMCs) of SLE patients compared to healthy controls. However, miR146a was significantly decreased in SLE patients compared to healthy controls and was negatively correlated with plasma estradiol levels and with SLE disease activity scores (SLEDAI). We also found that protein levels of IL-12 and IL-21 were significantly increased in SLE patients as compared to healthy controls. Further, our data shows that protein levels of IL-12 were positively correlated with miR21 expression and protein levels of IL-21 positively correlated with miR25 and miR186 expression in SLE patients. In addition, we found that levels of miR21, miR25, and miR186 positively correlated with SLEDAI and miR146a was negatively correlated in SLE patients. Thus, our data shows a dynamic interplay between disease pathogenesis and miRNA expression. This study has translational potential and may identify novel therapeutic targets in patients with SLE.

Differential Expression of miRNAs in Trichloroethene-Mediated Inflammatory/Autoimmune Response and Its Modulation by Sulforaphane: Delineating the Role of miRNA-21 and miRNA-690

Trichloroethene (TCE), an occupational and ubiquitous environmental contaminant, is associated with the induction of autoimmune diseases (ADs). Although oxidative stress plays a major role in TCE-mediated autoimmunity, the underlying molecular mechanisms still need to be delineated. Altered non-coding RNAs, including the expression of microRNAs (miRNAs), can influence target genes, especially related to apoptosis and inflammation, and contribute to ADs. Therefore, the objective of this study was to delineate the contribution of miRNAs in TCE-mediated inflammatory and autoimmune response. To achieve this, we treated female MRL+/+ mice with TCE (10 mmol/kg in corn oil, i.p., every fourth day) with/without antioxidant sulforaphane (SFN; 8 mg/kg in corn oil, i.p., every other day) for 6 weeks. With the use of miRNA microarray, 293 miRNAs were analyzed, which included 35 miRNAs that were relevant to inflammation and ADs. Among those 35 miRNAs, 8 were modulated by TCE and/or TCE+SFN exposure. TCE treatment led to increased expression of 3 miRNAs and also decreased expression of 3 miRNAs. Interestingly, among the 35 differentially expressed miRNAs, antioxidant SFN modulated the expression of 6 miRNAs. Based on the microarray findings, we subsequently focused on two miRNAs (miRNA-21 and miRNA-690), which are known to be involved in inflammation and autoimmune response. The increases in miRNA-21 and miR-690 (observed using miRNA microarray) were further validated by RT-PCR, and the TCE-mediated increases in miR-21 and miR-690 were ameliorated by SFN treatment. Modulating miR-21 and miR-690 by respective inhibitors or mimics suppressed the expression of NF-κB (p65) and IL-12 in RAW 264.7 cells. Our findings suggest a contributory role of miR-21 and miR-690 in TCE-mediated and its metabolite dichloroacetyl chloride (DCAC)-mediated inflammation and autoimmune response and support that antioxidant SFN could be a potential therapeutic candidate for inflammatory responses and ADs.

Long Non-Coding RNAs in Systemic Lupus Erythematosus: New Insights into Disease Pathogenesis and Diagnosis

Systemic lupus erythematosus (SLE) is a remarkable heterogeneous autoimmune disease that is sometimes hard to diagnose at the early stage and can lead to premature mortality. Long non-coding RNAs (lncRNAs) are a class of non-protein-coding RNAs greater than 200 nucleotides in length that can regulate gene expression in various human diseases, including SLE. Peripheral blood samples and renal tissue samples from SLE patients were used for study. Abnormally expressed lncRNAs in SLE have been shown to influence several signaling pathways, including the IFN-I, MAPK and WNT pathways. This can affect cellular phenotypes like cell activation, differentiation skewing, cytokine production, and cell apoptosis. Many of the reported lncRNAs may be useful for diagnosing, evaluating progression, and predicting potential organ damage in SLE patients. While numerous lncRNAs play important roles in SLE, more basic and clinical studies are warranted to clarify the function of these regulatory molecules and determine their diagnostic value.

Phenotypic Drift in Lupus-Prone MRL/lpr Mice: Potential Roles of MicroRNAs and Gut Microbiota

MRL/lpr mice have been extensively used as a murine model of lupus. Disease progression in MRL/lpr mice can differ among animal facilities, suggesting a role for environmental factors. We noted a phenotypic drift of our in-house colony, which was the progeny of mice obtained from The Jackson Laboratory (JAX; stocking number 000485), that involved attenuated glomerulonephritis, increased splenomegaly, and reduced lymphadenopathy. To validate our in-house mice as a model of lupus, we compared these mice with those newly obtained from JAX, which were confirmed to be genetically identical to our in-house mice. Surprisingly, the new JAX mice exhibited a similar phenotypic drift, most notably the attenuation of glomerulonephritis. Interestingly, our in-house colony differed from JAX mice in body weight and kidney size (both sexes), as well as in splenic size, germinal center formation, and level of anti-dsDNA auto-IgG in the circulation (male only). In addition, we noted differential expression of microRNA (miR)-21 and miR-183 that might explain the splenic differences in males. Furthermore, the composition of gut microbiota was different between in-house and new JAX mice at early time points, which might explain some of the renal differences (e.g., kidney size). However, we could not identify the reason for attenuated glomerulonephritis, a shared phenotypic drift between the two colonies. It is likely that this was due to certain changes of environmental factors present in both JAX and our facilities. Taken together, these results suggest a significant phenotypic drift in MRL/lpr mice in both colonies that may require strain recovery from cryopreservation.

Regulation of Adaptive Tumor Immunity by Non-Coding RNAs

Cancer immunology research has mainly focused on the role of protein-coding genes in regulating immune responses to tumors. However, despite more than 70% of the human genome is transcribed, less than 2% encodes proteins. Many non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), have been identified as critical regulators of immune cell development and function, suggesting that they might play important roles in orchestrating immune responses against tumors. In this review, we summarize the scientific advances on the role of ncRNAs in regulating adaptive tumor immunity, and discuss their potential therapeutic value in the context of cancer immunotherapy.

Dysregulated translational factors and epigenetic regulations orchestrate in B cells contributing to autoimmune diseases

B cells play a crucial role in antigen presentation, antibody production and pro-/anti-inflammatory cytokine secretion in adaptive immunity. Several translational factors including transcription factors and cytokines participate in the regulation of B cell development, with the cooperation of epigenetic regulations. Autoimmune diseases are generally characterized with autoreactive B cells and high-level pathogenic autoantibodies. The success of B cell depletion therapy in mouse model and clinical trials has proven the role of B cells in pathogenesis of autoimmune diseases. The failure of B cell tolerance in immune checkpoints results in accumulated autoreactive naïve B (B_N) cells with aberrant B cell receptor signaling and dysregulated B cell response, contributing to self-antibody-mediated autoimmune reaction. Dysregulation of translational factors and epigenetic alterations in B cells has been demonstrated to correlate with aberrant B cell compartment in autoimmune diseases, such as systemic lupus erythematosus, rheumatoid arthritis, primary Sjögren's syndrome, multiple sclerosis, diabetes mellitus and pemphigus. This review is intended to summarize the interaction of translational factors and epigenetic regulations that are involved with development and differentiation of B cells, and the mechanism of dysregulation in the pathogenesis of autoimmune diseases.

Immunological Involvement of MicroRNAs in the Key Events of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an archetype autoimmune disease characterized by a myriad of immunoregulatory abnormalities that drives injury to multiple tissues and organs. Due to the involvement of various immune cells, inflammatory cytokines, and related signaling pathways, researchers have spent a great deal of effort to clarify the complex etiology and pathogenesis of SLE. Nevertheless, current understanding of the pathogenesis of SLE is still in the early stages, and available nonspecific treatment options for SLE patients remain unsatisfactory. First discovered in 1993, microRNAs (miRNAs) are small RNA molecules that control the expression of 1/3 of human genes at the post-transcriptional level and play various roles in gene regulation. The aberrant expression of miRNAs in SLE patients has been intensively studied, and further studies have suggested that these miRNAs may be potentially relevant to abnormal immune responses and disease progression in SLE. The aim of this review was to summarize the specific miRNAs that have been observed aberrantly expressed in several important pathogenetic processes in SLE, such as DCs abnormalities, overactivation and autoantibody production of B cells, aberrant activation of CD4⁺ T cells, breakdown of immune tolerance, and abnormally increased production of inflammatory cytokines. Our summary highlights a novel perspective on the intricate regulatory network of SLE, which helps to enrich our understanding of this disorder and ignite future interest in evaluating the molecular regulation of miRNAs in autoimmunity SLE.

Context-Dependent miR-21 Regulation of TLR7-Mediated Autoimmune and Foreign Antigen-Driven Antibody-Forming Cell and Germinal Center Responses

MicroRNAs (miRNAs) are involved in healthy B cell responses and the loss of tolerance in systemic lupus erythematosus (SLE), although the role of many miRNAs remains poorly understood. Dampening miR-21 activity was previously shown to reduce splenomegaly and blood urea nitrogen levels in SLE-prone mice, but the detailed cellular responses and mechanism of action remains unexplored. In this study, using the TLR7 agonist, imiquimod-induced SLE model, we observed that loss of miR-21 in Sle1b mice prevented the formation of plasma cells and autoantibody-producing Ab-forming cells (AFCs) without a significant effect on the magnitude of the germinal center (GC) response. We further observed reduced dendritic cell and monocyte numbers in the spleens of miR-21-deficient Sle1b mice that were associated with reduced IFN, proinflammatory cytokines, and effector CD4⁺ T cell responses. RNA sequencing analysis on B cells from miR-21-deficient Sle1b mice revealed reduced activation and response to IFN, and cytokine and target array analysis revealed modulation of numerous miR-21 target genes in response to TLR7 activation and type I IFN stimulation. Our findings in the B6.Sle1bYaa (Sle1b ^Yaa) spontaneous model recapitulated the miR-21 role in TLR7-induced responses with an additional role in autoimmune GC and T follicular helper responses. Finally, immunization with T-dependent Ag revealed a role for miR-21 in foreign Ag-driven GC and Ab, but not AFC, responses. Our data suggest a potential multifaceted, context-dependent role for miR-21 in autoimmune and foreign Ag-driven AFC and GC responses. Further study is warranted to delineate the cell-intrinsic requirements and mechanisms of miR-21 during infection and SLE development.

miRNA-Mediated Control of B Cell Responses in Immunity and SLE

Loss of B cell tolerance is central to autoimmune diseases such as systemic lupus erythematosus (SLE). As such, the mechanisms involved in B cell development, maturation, activation, and function that are aberrantly regulated in SLE are of interest in the design of targeted therapeutics. While many factors are involved in the generation and regulation of B cell responses, miRNAs have emerged as critical regulators of these responses within the last decade. To date, miRNA involvement in B cell responses has largely been studied in non-autoimmune, immunization-based systems. However, miRNA profiles have also been strongly associated with SLE in human patients and these molecules have proven critical in both the promotion and regulation of disease in mouse models and in the formation of autoreactive B cell responses. Functionally, miRNAs are small non-coding RNAs that bind to complementary sequences located in target mRNA transcripts to mediate transcript degradation or translational repression, invoking a post-transcriptional level of genetic regulation. Due to their capacity to target a diverse range of transcripts and pathways in different immune cell types and throughout the various stages of development and response, targeting miRNAs is an interesting potential therapeutic avenue. Herein, we focus on what is currently known about miRNA function in both normal and SLE B cell responses, primarily highlighting miRNAs with confirmed functions in mouse models. We also discuss areas that should be addressed in future studies and whether the development of miRNA-centric therapeutics may be a viable alternative for the treatment of SLE.

Micro-RNAs in the regulation of immune response against SARS CoV-2 and other viral infections

Background

Micro-RNAs (miRNAS) are non-coding, small RNAs that have essential roles in different biological processes through silencing genes, they consist of 18-24 nucleotide length RNA molecules. Recently, miRNAs have been viewed as important modulators of viral infections they can function as suppressors of gene expression by targeting cellular or viral RNAs during infection.

Aim of review

We describe the biological roles and effects of miRNAs on SARS-CoV-2 life-cycle and pathogenicity, and we discuss the modulation of the immune system with micro-RNAs which would serve as a new foundation for the treatment of SARS-CoV-2 and other viral infections.

Key scientific concepts of review

miRNAs are the key players that regulate the expression of the gene in the post-transcriptional phase and have important effects on viral infections, thus are potential targets in the development of novel therapeutics for the treatment of viral infections. Besides, micro-RNAs (miRNAs) modulation of immune-pathogenesis responses to viral infection is one of the most-known indirect effects, which leads to suppressing of the interferon (IFN-α/β) signalling cascade or upregulation of the IFN-α/β production another IFN-stimulated gene (ISGs) that inhibit replication of the virus. These virus-mediated alterations in miRNA levels lead to an environment that might either enhance or inhibit virus replication.

microRNA Fine-Tuning of the Germinal Center Response

Germinal centers (GCs) are complex multicellular structures in which antigen-specific B cells undergo the molecular remodeling that enables the generation of high-affinity antibodies and the differentiation programs that lead to the generation of plasma–antibody-secreting cells and memory B cells. These reactions are tightly controlled by a variety of mechanisms, including the post-transcriptional control of gene expression by microRNAs (miRNAs). Through the development of animal models with B cell-specific modified miRNA expression, we have contributed to the understanding of the role of miRNAs in the regulation of GC responses and in B cell neoplasia. Here, we review recent advances in the understanding of the role of miRNAs in the regulation of B cell and T follicular helper physiology during the GC response and in the diseases associated to GC response dysregulation.

Association of LncRNA-GAS5 gene polymorphisms and PBMC LncRNA-GAS5 level with risk of systemic lupus erythematosus in Chinese population

Growth arrest‐specific 5 (GAS5) is a kind of long non‐coding RNAs (lncRNAs). Previous studies showed that down‐regulation of LncRNA‐GAS5 was involved in the development of systemic lupus erythematosus (SLE). However, the regulatory mechanism of down‐expressed LncRNA‐GAS5 in SLE remains obscure. In this study, we aimed to investigate the association of LncRNA‐GAS5 polymorphism with SLE risk. And further explore how LncRNA‐GAS5 is involved in the occurrence of SLE. Here, we evaluated the relationship between the risk for the development of SLE and the 5‐base pair (AGGCA/‐) insertion/deletion (I/D) polymorphism (rs145204276) in the LncRNA‐GAS5 promoter region. A custom 36‐Plex SNPscan kit was used for genotyping the LncRNA‐GAS5 polymorphisms. The LncRNA‐GAS5 and miR‐21 target prediction was performed using bioinformatics software. Enzyme‐linked immunosorbent assay (ELISA) and quantitative real‐time PCR (qRT‐PCR) were performed to assess GAS5 and miR‐21 mRNA expression and PTEN protein expression. The results revealed that rs145204276 resulted in a decreased risk of SLE (DD genotypes vs II genotypes: adjusted OR = 0.538, 95% CI, 0.30‐0.97, P = .039; ID genotypes vs II genotypes: adjusted OR = 0.641, 95% CI, 0.46‐0.89, P = .007; ID/DD genotypes vs II genotypes: adjusted OR = 0.621, 95% CI, 0.46‐0.84, P = .002; D alleles vs I alleles: adjusted OR = 0.680, 95% CI, 0.53‐0.87, P = .002). A reduced incidence of renal disorders in SLE was found to be related to ID/DD genotypes and D alleles (ID/DD genotypes vs II genotypes: OR = 0.57, 95% CI, 0.36‐0.92, P = .020; D alleles vs I alleles: OR = 0.63, 95% CI, 0.43‐0.93, P = .019). However, no significant association of rs2235095, rs6790, rs2067079 and rs1951625 polymorphisms with SLE risk was observed (P > .05). Additionally, haplotype analysis showed that a decreased SLE risk resulted from the A‐A‐C‐G‐D haplotype (OR = 0.67, 95% CI, 0.49‐0.91, P = .010). Also, patients in the SLE group showed a down‐regulated expression of LncRNA‐GAS5 and PTEN than the healthy volunteers; however, patients with rs145204276 ID/DD genotypes showed up‐regulated expression of LncRNA‐GAS5 and PTEN compared with patients carrying the II genotype. Furthermore, the miR‐21 levels were considerably up‐regulated in the SLE group than the healthy volunteers, and patients with rs145204276 ID/DD genotype had lower miR‐21 levels than the ones with the II genotype. Thus, we found that the LncRNA‐GAS5/miR‐21/PTEN signalling pathway was involved in the development of SLE, where LncRNA‐GAS5 acted as an miR‐21 target, and miR‐21 regulated the expression of PTEN. These findings indicated that the rs145204276 ID/DD genotypes in the LncRNA‐GAS5 gene promoter region may be protected against SLE by up‐regulating the expression of LncRNA‐GAS5, which consecutively regulated miR‐21 and PTEN levels.

HIF-1α and miR-210 differential and lineage-specific expression in systemic lupus erythematosus

Systemic lupus erythematosus (SLE, lupus) is a chronic autoimmune disease characterized by loss of peripheral tolerance to nuclear self-antigens. It is increasingly recognized that aberrant T cell metabolism is a critical mediator of SLE immunopathology. Hypoxia inducible factor 1⍺ (HIF-1α) is a key transcription factor that regulates T cell metabolism in response to immune stimuli. T cell activation induces HIF-1α expression and transcriptional activation of HIF-responsive genes. HypoxamiRs are a group of microRNAs sensitive to HIF-1α transcriptional regulation that function to fine-tune the HIF-driven transcriptional program. The 'master' hypoxamiR, miR-210 is transcriptionally regulated by HIF-1α and negatively regulates HIF-1α activity. Although a key role for HIF-1α in has been described in a number of autoimmune and inflammatory diseases and abnormal microRNA expression profiles correlate with poor clinical outcome in a number of rheumatologic diseases, the expression and function of HIF-1α and miR-210 in lupus remains largely uncharacterized. Here we report HIF-1α and miR-210 differential and lineage-specific expression in systemic lupus erythematosus. We show that HIF-1α mRNA and protein is overexpressed in human lupus CD4⁺ cells but not in CD8⁺ or CD19⁺ cells. RORγt, was upregulated in human lupus lymphocytes while FoxP3 expression remained unchanged. We show that miR-210 expression in lupus-prone mice correlates with disease activity and is robustly and selectively upregulated in CD4⁺ cells from both human lupus patients and lupus-prone mice. Our results suggest that abnormal HIF-1α and miR-210 expression contributes to SLE immune pathology and that HIF-1α/miR-210 may represent a novel and important regulatory axis in SLE.

MicroRNA control of B cell tolerance, autoimmunity and cancer

Since the discovery of the first microRNA (miRNA) in 1993, thousands of miRNAs have been identified in humans and mice and many of them have been shown to control a large variety of cellular processes in different cell types including those composing the immune system. MicroRNAs regulate virtually all aspects of immune cell development, differentiation and function. Studies have shown that these molecules are involved in the maintenance of lymphocyte tolerance and, when dysregulated, promote the development of autoimmune diseases. In this review, we focus on the current knowledge about the roles of miRNAs in B cell tolerance and their contribution to autoimmunity, highlighting additional roles for some of these miRNAs in T cell tolerance. Finally, we will comment on miRNAs that promote both autoimmunity and lymphoma.

Plasma microRNA levels in childhood IgA vasculitis

INTRODUCTION

Immunoglobulin A vasculitis (IgAV) is the most common form of childhood systemic vasculitis. It is mostly self-limiting and characterized by skin, joint, gastrointestinal tract, and kidney involvement. Microribonucleic acids (miRNAs) are 18-25 base-long non-coding RNA group acting on gene expression. They have been shown to be effective on the immune system studies to date.

METHOD

In our study, 24 IgAV children with skin and joint involvement and 24 healthy children were included. Five different miRNAs (miR-33, miR-34, miR-122, miR-204, and miR451) known to be expressed in plasma and related with autoimmunity pathogenesis were evaluated. miRNAs were compared between the active period of the disease, the post-treatment period, and the healthy group using the real-time PCR method.

RESULTS

Expression levels of miRNA-33 and miRNA-34 increased significantly in active period of the patients compare with inactive period and control groups. The expression levels of miRNA-122 and miRNA-204 decreased significantly in active period of the patients compare with other two groups. There was no significant difference in miRNA-451 levels.

CONCLUSIONS

With the experience we gained from our recent studies, we think that miRNA-204 may be a significant biomarker in autoimmune diseases. Our study is the first study between IgAV and miRNAs in children. More studies are needed to reveal this relationship. Key Points • This is the first paper to show the relationship between miRNAs and childhood IgAV. • It will provide a new perspective to evaluate the pathogenesis of the disease.

Reprogramming of miR-181a/DNA methylation patterns contribute to the maternal nicotine exposure-induced fetal programming of cardiac ischemia-sensitive phenotype in postnatal life

Background: E-cigarette and other novel electronic nicotine delivery systems (ENDS) have recently entered the market at a rapid pace. The community desperately needs answers about the health effects of ENDS. The present study tested the hypothesis that perinatal nicotine exposure (PNE) causes a gender-dependent increase in vulnerability of the heart to ischemia-reperfusion (I/R) injury and cardiac dysfunction in male rat offspring via reprogramming of the miRNA-181a (miR-181a)-mediated signaling pathway and that miR-181a antisense could rescue this phenotype. Methods: Nicotine or saline was administered to pregnant rats via subcutaneous osmotic minipumps from gestational day 4 until postnatal day 10. Cardiac function and molecular biological experiments were conducted in ~3- month-old offspring. Results: PNE enhanced I/R-induced cardiac dysfunction and infarction in adult male but not in female offspring, which was associated with miR-181a over-expression in left ventricle tissues. In addition, PNE enhanced offspring cardiac angiotensin receptor (ATR) expressions via specific CpG hypomethylation of AT₁R/AT₂R promoter. Furthermore, PNE attenuated cardiac lncRNA H19 levels, but up-regulated cardiac TGF-β/Smads family proteins and consequently up-regulated autophagy-related protein (Atg-5, beclin-1, LC3 II, p62) expression in the male offspring. Of importance, treatment with miR-181a antisense eliminated the PNE's effect on miR-181a expression/H19 levels and reversed PNE-mediated I/R-induced cardiac infarction and dysfunction in male offspring. Furthermore, miR-181a antisense also attenuated the effect of PNE on AT₁R/AT₂R/TGF-β/Smads/autophagy-related biomarkers in the male offspring. Conclusion: Our data suggest that PNE could induce a reprogramming of cardiac miR-181a expression/DNA methylation pattern, which epigenetically modulates ATR/TGF-β/autophagy signaling pathways, leading to gender-dependent development of ischemia-sensitive phenotype in postnatal life. Furthermore, miR-181a could severe as a potential therapeutic target for rescuing this phenotype.

MicroRNA-30e-5p has an Integrated Role in the Regulation of the Innate Immune Response during Virus Infection and Systemic Lupus Erythematosus

Precise regulation of innate immunity is crucial for development of appropriate host immunity against microbial infections and maintenance of immune homeostasis. MicroRNAs are small non-coding RNAs, post-transcriptional regulator of multiple genes, and act as a rheostat for protein expression. Here, we identified microRNA-30e-5p induced by hepatitis B virus and other viruses that act as a master regulator for innate immunity. Moreover, pegylated interferons treatment of patients with HBV for viral reduction also reduces miRNA. Additionally, we have also shown the immuno-pathological effects of miR-30e in patients with systemic lupus erythematosus (SLE) and mouse model. Mechanistically, miR-30e targets multiple negative regulators of innate immune signaling and enhances immune responses. Furthermore, sequestering of miR-30e in patients with SLE and mouse model significantly reduces type-I interferon and pro-inflammatory cytokines. Collectively, our study demonstrates the novel role of miR-30e in innate immunity and its prognostic and therapeutic potential in infectious and autoimmune diseases.

miR-21, Mediator, and Potential Therapeutic Target in the Cardiorenal Syndrome

Oligonucleotide-based therapies are currently gaining attention as a new treatment option for relatively rare as well as common diseases such as cardiovascular disease. With the remarkable progression of new sequencing technologies, a further step towards personalized precision medicine to target a disease at a molecular level was taken. Such therapies may employ antisense oligonucleotides to modulate the expression of both protein coding and non-coding RNAs, such as microRNAs. The cardiorenal syndrome (CRS) is a complex and severe clinical condition where heart and renal dysfunction mutually affect one another. The underlying mechanisms remain largely unknown and current treatments of CRS are mainly supportive therapies which slow down the progression of the disease, but hardly improve the condition. The small non-coding RNA, microRNA-21 (miR-21), is dysregulated in various heart and kidney diseases and has been repeatedly suggested as therapeutic target for the treatment of CRS. Impressive preclinical results have been achieved by an antisense oligonucleotide-based therapy to effectively block the pro-fibrotic traits of miR-21. Since microRNA-mediated pathways are generally very well-conserved, there is considerable commercial interest with regards to clinical translation. In this review, we will summarize the role of miR-21 within the heart–kidney axis and discuss the advantages and pitfalls of miR-21 targeting therapeutic strategies in CRS.

MicroRNAs in Systemic Lupus Erythematosus: a Perspective on the Path from Biological Discoveries to Clinical Practice

PURPOSE OF REVIEW

MicroRNAs (miRNAs) play essential roles in immune abnormalities and organ damage of systemic lupus erythematosus (SLE). Current findings have indicated potential clinical applications of miRNAs for combating SLE. Here, we review recent evidence which support the notions that miRNAs can be novel biomarkers and therapeutic agents for SLE.

RECENT FINDINGS

Following years of the studies of the expression patterns of miRNAs in both peripheral blood cells and body fluids, such as plasma and urine, several miRNAs or miRNA combinations have been associated with disease activity and specific organ damage. In depth analysis reveals complex and multiple roles of certain miRNAs in the pathogenesis of SLE. Manipulating miRNA expression shows in vivo therapeutic effects in lupus mouse models. MiRNAs contribute to the immune disorders and organ damage in SLE. MiRNA based biomarkers and therapies have the potential to be viable options for the treatment of SLE.

Non-Coding RNAs in CD4+ T Cells: New Insights Into the Pathogenesis of Systemic Lupus Erythematosus

Non-coding RNAs (ncRNAs) are indispensable for CD4⁺ T cell differentiation and functions. By directly or indirectly regulating immune gene expression, ncRNAs give flexible instructions to guide the biological processes of CD4⁺ T cells and play a vital role in maintaining immune homeostasis. However, the dysfunction of ncRNAs alters the gene expression profiles, disturbs the normal biological processes of CD4⁺ T cells, and leads to the functional changes of CD4⁺ T cells, which is an underlying cause of systemic lupus erythematosus (SLE). In this review, we focus on the recent advances in the roles of ncRNAs in CD4⁺ T cell functions and differentiation, as well as their potential applications in the diagnosis and treatment of SLE.

Non-coding RNAs - A primer for the laboratory scientist

Advances in molecular genetics have identified several species of RNA that fail to translate - hence the non-coding RNAs. The two major groups within this class of nucleic acids are microRNAs (miRNA) and long non-coding RNAs (lncRNA). There is growing body of evidence supporting the view that these molecules have regulatory effect on both DNA and RNA. The objective of this brief review is to explain the molecular genetic of these molecules, to summarize their potential as mediators of disease, and to highlight their value as diagnostic markers and as tools in disease management.

Long non-coding RNAs in immune regulation and their potential as therapeutic targets

Long non-coding RNAs (lncRNAs) are potent regulators of immune cell development and function. Their implication in multiple immune-mediated disorders highlights lncRNAs as exciting biomarkers and potential drug targets. Recent technological innovations in oligo-based therapeutics, development of RNA-targeting small molecules, and CRISPR-based approaches, position RNA as the next therapeutic frontier. Here, we review the latest advances made toward understanding the role of lncRNAs in human immunological disorders and further discuss RNA-targeting approaches that could be potentially exploited to manipulate lncRNA function as a clinical intervention.

Downregulation of microRNA-101-3p participates in systemic lupus erythematosus progression via negatively regulating HDAC9

This study aimed to investigate the mechanism of microRNA-101-3p (miR-101-3p) on the progression of systemic lupus erythematosus (SLE). The human peripheral blood mononuclear cells (PBMCs) were isolated from whole blood samples of SLE patients and healthy individuals, followed by cell culture and transfection. Moreover, the flow cytometry assay, quantitative real-time reverse-transcription polymerase chain reaction, Western blot, and enzyme-linked immunoassay were used to assess the effect of miR-101-3p on PBMCs. Bioinformatics analysis was conducted to predict the putative target gene of miR-101-3p, luciferase reporter gene assay, and RNA pull-down assay were applied to verify the interaction between them. Compared with healthy individuals, the expression level of miR-101-3p in PBMCs of SLE patients was significantly decreased, whereas interleukin (IL)-17A, IL-6, and interferon (IFN)-γ were remarkably increased (all P < .001). Correlation analyses showed that there were negative correlations between miR-101-3p and IL-17A, IL-6 and IFN-γ. The expression level of miR-101-3p in PBMCs of SLE patients was positively correlated with C3 expression (r_s  = .4075; P = .0229), while negatively associated with erythrocyte sedimentation rate (ESR) (r_s  = -.4238; P = .0175) and IgG expression (r_s  = -.4949; P = .0047). Overexpression of miR-101-3p could inhibit the differentiation of CD4 + T cells into Th17 lineage. Histone deacetylase 9 (HDAC9) was identified as a potential target gene of miR-101-3p. Furthermore, HDAC9 abolished the effect of miR-101-3p on Th17 cell differentiation and IL-17A expression in SLE. In conclusion, downregulated miR-101-3p in PBMCs of SLE patients inhibited Th17 cell differentiation by directly targeting HDAC9, which could be used as a novel therapeutic therapy for SLE treatment.

The Epigenetics of Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a life-threatening autoimmune disease that is characterized by dysregulated dendritic cells, T and B cells, and abundant autoantibodies. The pathogenesis of lupus remains unclear. However, increasing evidence has shown that environment factors, genetic susceptibilities, and epigenetic regulation contribute to abnormalities in the immune system. In the past decades, several risk gene loci have been identified, such as MHC and C1q. However, genetics cannot explain the high discordance of lupus incidence in homozygous twins. Environmental factor-induced epigenetic modifications on immune cells may provide some insight. Epigenetics refers to inheritable changes in a chromosome without altering DNA sequence. The primary mechanisms of epigenetics include DNA methylation, histone modifications, and non-coding RNA regulations. Increasing evidence has shown the importance of dysregulated epigenetic modifications in immune cells in pathogenesis of lupus, and has identified epigenetic changes as potential biomarkers and therapeutic targets. Environmental factors, such as drugs, diet, and pollution, may also be the triggers of epigenetic changes. Therefore, this chapter will summarize the up-to-date progress on epigenetics regulation in lupus, in order to broaden our understanding of lupus and discuss the potential roles of epigenetic regulations for clinical applications.

Elevation of long non-coding RNA GAS5 and knockdown of microRNA-21 up-regulate RECK expression to enhance esophageal squamous cell carcinoma cell radio-sensitivity after radiotherapy

OBJECTIVE

Lately, lncRNAs have been proposed to function in the radio-sensitivity of tumor cells, yet the role of lncRNA GAS5 in that of esophageal squamous cell carcinoma (ESCC) has scarcely been studied. This study aims to examine GAS5's effects on ESCC cell radio-sensitivity.

METHODS

GAS5, miR-21 and RECK expression in radiation-sensitive and radiation-resistant ESCC tissues, and TE-1 and TE-1-R cells was determined. TE-1 and TE-1-R cells were treated with pcDNA-GAS5 or miR-21 inhibitors to figure out their roles in ESCC cell proliferation, radio-sensitivity, and apoptosis via gain- and loss-of-function experiments.

RESULTS

We found underexpressed GAS5 and RECK, and overexpressed miR-21 in ESCC. GAS5 elevation and miR-21 inhibition reduced viability and the colony formation ability, and enhanced the apoptosis of ESCC cells under radiation.

CONCLUSION

Our study reveals that GAS5 elevation up-regulates RECK expression by down-regulating miR-21 to increase ESCC cell apoptosis after radiation therapy, thus enhancing cell radio-sensitivity.

The Pathogenic Role of Dysregulated Epigenetic Modifications in Autoimmune Diseases

Autoimmune diseases can be chronic with relapse of inflammatory symptoms, but it can be also acute and life-threatening if immune cells destroy life-supporting organs, such as lupus nephritis. The etiopathogenesis of autoimmune diseases has been revealed as that genetics and environmental factors-mediated dysregulated immune responses contribute to the initiation and development of autoimmune disorders. However, the current understanding of pathogenesis is limited and the underlying mechanism has not been well defined, which lows the development of novel biomarkers and new therapeutic strategies for autoimmune diseases. To improve this, broadening and deepening our understanding of pathogenesis is an unmet need. As genetic susceptibility cannot explain the low accordance rate of incidence in homozygous twins, epigenetic regulations might be an additional explanation. Therefore, this review will summarize current progress of studies on epigenetic dysregulations contributing to autoimmune diseases, including SLE, rheumatoid arthritis (RA), psoriasis, type 1 diabetes (T1D), and systemic sclerosis (SSc), hopefully providing opinions on orientation of future research, as well as discussing the clinical utilization of potential biomarkers and therapeutic strategies for these diseases.

MiR-205-5p inhibition by locked nucleic acids impairs metastatic potential of breast cancer cells

Mir-205 plays an important role in epithelial biogenesis and in mammary gland development but its role in cancer still remains controversial depending on the specific cellular context and target genes. We have previously reported that miR-205-5p is upregulated in breast cancer stem cells targeting ERBB pathway and leading to targeted therapy resistance. Here we show that miR-205-5p regulates tumorigenic properties of breast cancer cells, as well as epithelial to mesenchymal transition. Silencing this miRNA in breast cancer results in reduced tumor growth and metastatic spreading in mouse models. Moreover, we show that miR-205-5p knock-down can be obtained with the use of specific locked nucleic acids oligonucleotides in vivo suggesting a future potential use of this approach in therapy.

MicroRNA-mediated immune regulation in rheumatic diseases

MicroRNAs (miRNAs) are endogenous small, non-coding RNAs that regulate genome expression at the post-transcriptional level. They are involved in a wide range of physiological processes including the maintenance of immune homeostasis and normal function. Accumulating evidence from animal studies show that alterations in pan or specific miRNA expression would break immunological tolerance, leading to autoimmunity. Differential miRNA expressions have also been documented in patients of many autoimmune disorders. In this review, we highlight the evidence that signifies the critical role of miRNAs in autoimmunity, specifically on their regulatory roles in the pathogenesis of several rheumatic diseases including systemic lupus erythematosus, rheumatoid arthritis and spondyloarthritis. The potential of miRNAs as biomarkers and therapeutic targets is also discussed. Manipulation of dysregulated miRNAs in vivo through miRNA delivery or inhibition offers promise for new therapeutic strategies in treating rheumatic diseases.

The Involvement of MicroRNAs in Modulation of Innate and Adaptive Immunity in Systemic Lupus Erythematosus and Lupus Nephritis

Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), represent a family of RNA molecules that do not translate into protein. Nevertheless, they have the ability to regulate gene expression and play an essential role in immune cell differentiation and function. MicroRNAs were found to be differentially expressed in various tissues, and changes in their expression have been associated with several pathological processes. Yet, their roles in systemic lupus erythematosus (SLE) and lupus nephritis (LN) remain to be elucidated. Both SLE and LN are characterized by a complex dysfunction of the innate and adaptive immunity. Recently, significant findings have been made in understanding SLE through the use of genetic variant identification and expression pattern analysis and mouse models, as well as epigenetic analyses. Abnormalities in immune cell responses, cytokine and chemokine production, cell activation, and apoptosis have been linked to a unique expression pattern of a number of miRNAs that have been implicated in the immune pathogenesis of this autoimmune disease. The recent evidence that significantly increased the understanding of the pathogenesis of SLE drives a renewed interest in efficient therapy targets. This review aims at providing an overview of the current state of research on the expression and role of miRNAs in the immune pathogenesis of SLE and LN.

A MicroRNA Signature for Evaluation of Risk and Severity of Autoimmune Thyroid Diseases

CONTEXT

Circulating microRNAs (miRNAs) are emerging as an interesting research area because of their potential role as novel biomarkers and therapeutic targets. Their involvement in autoimmune thyroid diseases (AITDs) has not been fully explored.

OBJECTIVE

To compare the expression profile of miRNAs in thyroid tissue from patients with AITD and controls, using next-generation sequencing, further validated our findings in thyroid and serum samples.

DESIGN

Twenty fresh-frozen thyroid tissues (15 from patients with AITD and 5 from controls) were used for miRNA next-generation sequencing. Thirty-six thyroid samples were recruited for the qRT-PCR validation test and 58 serum samples for further validation in peripheral blood.

RESULTS

Expression of several miRNAs that had been previously associated with relevant immunological functions was significantly dysregulated. Specifically, eight differentially expressed miRNAs (miR-21-5p, miR-142-3p, miR-146a-5p, miR-146b-5p, miR-155-5p, miR-338-5p, miR-342-5p, and miR-766-3p) were confirmed using qRT-PCR in thyroid samples, and three had the same behavior in tissue and serum samples (miR-21-5p, miR-142-3p, and miR-146a-5p). Furthermore, when the expression of these miRNAs was assessed together with five additional ones previously related to AITD in peripheral blood, the expression of five (miR-Let7d-5p, miR-21-5p, miR-96-5p, miR-142-3p, and miR-301a-3p) was significantly expressed in AITD and, in patients with Graves disease (GD), was correlated with a higher severity of disease, including active ophthalmopathy, goiter, higher antibody titers, and/or higher recurrence rates.

CONCLUSIONS

The present findings identify a serum five-signature miRNA that could be an independent risk factor for developing AITD and a predisposition of a worse clinical picture in patients with GD.

Epigenetic regulation in B-cell maturation and its dysregulation in autoimmunity

B cells have a critical role in the initiation and acceleration of autoimmune diseases, especially those mediated by autoantibodies. In the peripheral lymphoid system, mature B cells are activated by self or/and foreign antigens and signals from helper T cells for differentiating into either memory B cells or antibody-producing plasma cells. Accumulating evidence has shown that epigenetic regulations modulate somatic hypermutation and class switch DNA recombination during B-cell activation and differentiation. Any abnormalities in these complex regulatory processes may contribute to aberrant antibody production, resulting in autoimmune pathogenesis such as systemic lupus erythematosus. Newly generated knowledge from advanced modern technologies such as next-generation sequencing, single-cell sequencing and DNA methylation sequencing has enabled us to better understand B-cell biology and its role in autoimmune development. Thus this review aims to summarize current research progress in epigenetic modifications contributing to B-cell activation and differentiation, especially under autoimmune conditions such as lupus, rheumatoid arthritis and type 1 diabetes.