MicroRNA-125a contributes to elevated inflammatory chemokine RANTES levels via targeting KLF13 in systemic lupus erythematosus

MicroRNA-125b mediates Interferon-γ-induced downregulation of the vitamin D receptor in systemic lupus erythematosus

BACKGROUND

The inflammatory factor interferon (IFN)-γ is related to the occurrence and development of systemic lupus erythematosus (SLE). The vitamin D receptor (VDR) has an anti-inflammatory effect and its downregulation is involved in the onset of SLE. Our previous studies have confirmed that the expression of VDR in SLE peripheral blood mononuclear cells (PBMCs) is downregulated, which is negatively correlated with disease activity and inflammation. However, the mechanism underlying VDR downregulation in SLE is unknown.

METHODS

Based on the results of computer simulation analysis, the expression of VDR and four microRNAs (miR-17-3p, miR-34a, miR-346, and miR-125b) in SLE PBMC cells was analyzed under proinflammatory cytokine IFN‑γ treatment, and miR-125b was identified as the target miRNA. The relationship between IFN‑γ, miR-125b, and VDR was further assessed in THP‑1 cells.

RESULTS

We showed that IFN‑γ inhibited the expression of VDR and miR-125b. Further study revealed that VDR mRNA was positively correlated with miR-125b in THP‑1 cells after IFN‑γ intervention. After transfection of miR-125b mimic or inhibitor, the expression of VDR in the miR-125b inhibitor group was lower than in the control group and miR-125b mimic group, while expression in the control group was lower than in miR-125b mimic group. Transfection of miR-125b inhibitor into THP‑1 cells could further promote the ability of IFN‑γ to inhibit VDR.

CONCLUSION

The decrease in VDR expression promotes development of inflammation and SLE. These data suggest that miR-125b may mediate inflammatory factor IFN-γ-induced downregulation of VDR in the pathogenesis of SLE.

Epigenetic Dysregulation in the Pathogenesis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease in which immune disorders lead to autoreactive immune responses and cause inflammation and tissue damage. Genetic and environmental factors have been shown to trigger SLE. Recent evidence has also demonstrated that epigenetic factors contribute to the pathogenesis of SLE. Epigenetic mechanisms play an important role in modulating the chromatin structure and regulating gene transcription. Dysregulated epigenetic changes can alter gene expression and impair cellular functions in immune cells, resulting in autoreactive immune responses. Therefore, elucidating the dysregulated epigenetic mechanisms in the immune system is crucial for understanding the pathogenesis of SLE. In this paper, we review the important roles of epigenetic disorders in the pathogenesis of SLE.

Altered expression of miR-125a and dysregulated cytokines in systemic lupus erythematosus: Unveiling diagnostic and prognostic markers

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder impacting multiple organs, influenced by genetic factors, especially those related to the immune system. However, there is a need for new biomarkers in SLE. MicroRNA-125a (miR-125a) levels are decreased in T cells, B cells, and dendritic cells of SLE patients. MiR-125a plays a regulatory role in controlling the levels of tumor necrosis factor-alpha (TNF-α) and interleukin 12 (IL-12), which are crucial pro-inflammatory cytokines in SLE pathogenesis.

AIM

To assess the levels of miR-125a, IL-12, and TNF-α in SLE patients' plasma, evaluating their diagnostic and prognostic value.

METHODS

The study included 100 healthy individuals, 50 newly diagnosed (ND), and 50 SLE patients undergoing treatment. The patients were monitored for a duration of 24 wk to observe and record instances of relapses. MiR-125a expression was measured using real-time reverse transcription polymerase chain reaction, while ELISA kits were used to assess IL-12 and TNF-α production.

RESULTS

The results showed significantly reduced miR-125a expression in SLE patients compared to healthy individuals, with the lowest levels in ND patients. TNF-α and IL-12 expression levels were significantly elevated in SLE patients, especially in the early stages of the disease. Receiver operating characteristic curve analyses, and Cox-Mantel Log-rank tests indicated miR-125a, TNF-α, and IL-12 as proper diagnostic biomarkers for SLE. A negative correlation was found between plasma miR-125a expression and IL-12/TNF-α levels in SLE patients.

CONCLUSION

Decreased miR-125a levels may be involved in the development of SLE, while elevated levels of IL-12 and TNF-α contribute to immune dysregulation. These findings offer new diagnostic and prognostic markers for SLE. Moreover, the negative correlation observed suggests an interaction between miR-125a, TNF-α, and IL-12. Further research is necessary to uncover the underlying mechanisms that govern these relationships.

MicroRNA as a potential biomarker for systemic lupus erythematosus: pathogenesis and targeted therapy

Systemic lupus erythematosus (SLE) is an autoimmune disease associated with hyperactive innate and adaptive immune systems that cause dermatological, cardiovascular, renal, and neuropsychiatric problems in patients. SLE's multifactorial nature and complex pathogenesis present significant challenges in its clinical classification. In addition, unpredictable treatment responses in patients emphasize the need for highly specific and sensitive SLE biomarkers that can assist in understanding the exact pathogenesis and, thereby, lead to the identification of novel therapeutic targets. Recent studies on microRNA (miRNA), a non-coding region involved in the regulation of gene expression, indicate its importance in the development of the immune system and thus in the pathogenesis of various autoimmune disorders such as SLE. miRNAs are fascinating biomarker prospects for SLE categorization and disease monitoring owing to their small size and high stability. In this paper, we have discussed the involvement of a wide range of miRNAs in the regulation of SLE inflammation and how their modulation can be a potential therapeutic approach.

MicroRNA-125a-5p regulates the effect of Tregs on Th1 and Th17 through targeting ETS-1/STAT3 in psoriasis

BACKGROUND

Psoriasis is an inflammatory disease mediated by helper T (Th)17 and Th1 cells. MicroRNA-125a (miR-125a) is reduced in the lesional skin of psoriatic patients. However, the mechanism by which miR-125a participates in psoriasis remains unclear.

METHODS

The levels of miR-125a-5p and its downstream targets (ETS-1, IFN-γ, and STAT3) were detected in CD4+ T cells of healthy controls and psoriatic patients by quantitative real-time PCR (qRT-PCR). In vitro, transfection of miR-125a-5p mimics was used to analyze the effect of miR-125a-5p on the differentiation of Th17 cells by flow cytometry. Imiquimod (IMQ)-induced mouse model was used to evaluate the role of upregulating miR-125a-5p by intradermal injection of agomir-125a-5p in vivo.

RESULTS

miR-125a-5p was downregulated in peripheral blood CD4+ T cells of psoriatic patients, which was positively associated with the proportion of regulatory T cells (Tregs) and negatively correlated with the Psoriasis Area and Severity Index (PASI) score. Moreover, the miR-125a-5p mimics promoted the differentiation of Tregs and downregulated the messenger RNA (mRNA) levels of ETS-1, IFN-γ, and STAT3 in murine CD4+ T cells. Furthermore, agomir-125a-5p alleviated psoriasis-like inflammation in an IMQ-induced mouse model by downregulating the proportion of Th17 cells.

CONCLUSIONS

miR-125a-5p may have therapeutic potential in psoriasis by restoring the suppressive function of Tregs on Th17 cells through targeting STAT3, and on Th1 cells indirectly through targeting ETS-1 and IFN-γ.

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.

Replication of association at the LPP and UBASH3A loci in a UK autoimmune Addison's disease cohort

Autoimmune Addison's disease (AAD) arises from a complex interplay between multiple genetic susceptibility polymorphisms and environmental factors. The first genome wide association study (GWAS) with patients from Scandinavian Addison's registries has identified association signals at four novel loci in the genes LPP, SH2B3, SIGLEC5, and UBASH3A. To verify these novel risk loci, we performed a case-control association study in our independent cohort of 420 patients with AAD from the across the UK. We report significant association of alleles of the LPP and UBASH3A genes [odds ratio (95% confidence intervals), 1.46 (1.21-1.75)and 1.40 (1.16-1.68), respectively] with AAD in our UK cohort. In addition, we report nominal association of AAD with SH2B3 [OR 1.18 (1.02-1.35)]. We confirm that variants at the LPP and UBASH3A loci confer susceptibility to AAD in a UK population. Further studies with larger patient cohorts are required to robustly confirm the association of SH2B3 and SIGLEC5/SPACA6 alleles.

Anti-inflammatory effect of miR-125a-5p on experimental optic neuritis by promoting the differentiation of Treg cells

Methylprednisolone pulse treatment is currently used for optic neuritis. It can speed visual recovery, but does not improve the ultimate visual outcomes. Recent studies have reported that miR-125a-5p has immunomodulatory effects on autoimmune diseases. However, it remains unclear whether miR-125a-5p has effects on optic neuritis. In this study, we used adeno-associated virus to overexpress or silence miR-125a-5p in mice. We found that silencing miR-125a-5p increased the latency of visual evoked potential and aggravated inflammation of the optic nerve. Overexpression of miR-125a-5p suppressed inflammation of the optic nerve, protected retinal ganglion cells, and increased the percentage of Treg cells. Our findings show that miR-125a-5p exhibits anti-inflammatory effects through promoting the differentiation of Treg cells.

UC-BSCs Exosomes Regulate Th17/Treg Balance in Patients with Systemic Lupus Erythematosus via miR-19b/KLF13

Umbilical cord blood mesenchymal stem cells (UC-BSCs) are cells with low immunogenicity and differentiation potential, and the transfer of exosomes carried by UC-BSCs can regulate innate and adaptive immunity and affect immune homeostasis. This is an area of focus for autoimmune illnesses such as systemic lupus erythematosus (SLE). The target of this research was to investigate the immunomodulatory effect of exosomes produced from mesenchymal stem cells on SLE and its mechanism. After isolation of peripheral blood mononuclear cells (PBMC) from the SLE group and healthy group and treatment of SLE-derived PBMCs with UC-BSC-derived exosomes, the mRNA levels of corresponding factors in cells under different treatments were determined by RT-PCR, Th17/Treg content was analyzed by FCM (flow cytometry), and the targeted binding of microRNA-19b (miR-19b) to KLF13 was identified by in vitro experiments and bioinformatics analysis. The findings demonstrated that PBMC cells from SLE patients had higher proportions of Th17 subsets than the control group, whereas Treg subgroups with lower percentages were discovered. miR-19b's expression level was markedly reduced, which was inversely associated to the concentration of KLF13. In vitro experiments show that UC-BSC-derived exosome treatment can target KLF13 expression by increasing the miR-19b level, thereby regulating Th17/Treg balance and inhibiting the expression of inflammatory factors. According to the study's findings, SLE patients have dysregulated expression of the genes miR-19b and KLF13, and UC-BSC exosomes could regulate Th17/Treg cell balance and inflammatory factor expression in SLE patients through miR-19b/KLF13.

Chemokine receptor 7 mediates miRNA-182 to regulate cerebral ischemia/reperfusion injury in rats

AIMS

Chemokine receptor 7 (CXCR7) exerts protective effects on the brain. MicroRNAs (miRNAs) are involved in cerebral ischemia/reperfusion (I/R) injury, but their involvement in CXCR7-mediated brain protection is unknown. In this study, we investigated the role of miRNAs in CXCR7-mediated brain protection.

METHODS

CXCR7 levels in peripheral blood samples from patients with acute ischemic stroke (AIS) and ischemic penumbra area brain tissues from middle cerebral artery occlusion (MCAO) rats after recanalization were measured. An miRNA microarray analysis was performed to examine the expression of miRNAs caused by CXCR7 knockdown in ischemic penumbra area brain tissue in middle cerebral artery occlusion-reperfusion rats and to predict corresponding downstream target genes. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed the most enriched pathways. A dual-luciferase reporter assay confirmed the direct regulation of miR-182 on the target gene TCF7L2. The correlation between TCF7L2 and CXCR7/miR-182 was verified using rescue assays.

RESULTS

CXCR7 expression was upregulated in MCAO rats and mechanical thrombectomy patients with AIS compared to that in controls. The motor and sensory functions of MCAO rats with CXCR7 knockdown further decreased, and the infarct volume and cerebral edema increased. miRNA microarray data showed that seven miRNAs were differentially expressed after shRNA-CXCR7 treatment. The dual-luciferase reporter assay confirmed that miR-182 directly targeted the TCF7L2 gene. Rescue assays confirmed that TCF7L2 is downstream of CXCR7/miR-182. KEGG pathway analysis showed that the Hippo pathway may be a key pathway in CXCR7 upregulation and plays a role in protecting the brain after interventional surgery. Animal experiments have shown that CXCR7-mediated cerebral I/R injury promotes the phosphorylation of key molecules YAP and TAZ in the Hippo pathway.

CONCLUSION

CXCR7 protects against cerebral I/R injury, possibly via the miR-182/TCF7L2/Hippo pathway. These results indicate that CXCR7 affects cerebral ischemia-reperfusion injury through miRNA regulation and downstream pathways.

Peripheral immune challenges elicit differential up-regulation of hippocampal cytokine and chemokine mRNA expression in a mouse model of the 15q13.3 microdeletion syndrome

The human heterozygous 15q13.3 microdeletion is associated with neuropathological disorders, most prominently with epilepsy and intellectual disability. The 1.5 Mb deletion encompasses six genes (FAN1 [MTMR15], MTMR10, TRPM1, KLF13, OTUD7A, and CHRNA7); all but one (TRPM1) are expressed in the brain. The 15q13.3 microdeletion causes highly variable neurological symptoms, and confounding factors may contribute to a more severe phenotype. CHRNA7 and KLF13 are involved in immune system regulation and altered immune responses may contribute to neurological deficits. We used the Df[h15q13]/+ transgenic mouse model with a heterozygous deletion of the orthologous region (Het) to test the hypothesis that the microdeletion increases innate immune responses compared to wild type (WT). Male and female mice were acutely challenged with the bacteriomimetic lipopolysaccharide (LPS, 0.1 mg/kg, i.p.) or the viral mimetic polyinosinic:polycytidylic acid (Poly(I:C), 5 mg/kg). Hippocampal mRNA expression of pro-inflammatory cytokines and chemokines were determined three hours after injection using quantitative PCR analysis. In controls, expression was not affected by sex or genotype. LPS and Poly(I:C) resulted in significantly increased hippocampal expression of cytokines, chemokines, and interferon-γ (IFNγ), with more robust increases for TNF-α, IL-6, IL-1β, CXCL1, and CCL2 by LPS, higher induction of IFNγ by Poly(I:C), and similar increases of CCL4 and CCL5 by both agents. Generally, Hets exhibited stronger responses than WT mice, and significant effects of genotype or genotype × treatment interactions were detected for CXCL1 and CCL5, and IL-6, IL-1β, and CCL4, respectively, after LPS. Sex differences were detected for some targets. LPS but not Poly(I:C), reduced overnight burrowing independent of sex or genotype, suggesting that LPS induced sickness behavior. Thus, mice carrying the microdeletion have an increased innate immune response following a LPS challenge, but further studies will have to determine the extent and mechanisms of altered immune activation and subsequent contributions to 15q13.3 microdeletion associated deficits.

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.

Expanding Roles of Noncoding RNAs in the Pathogenesis of Systemic Lupus Erythematosus

PURPOSE OF REVIEW

The exact pathogenesis of systemic lupus erythematosus (SLE) remains unclear. Accumulating finds have indicated the roles of the non-coding RNAs (ncRNAs) acting as novel epigenetic regulatory elements in the dysfunction of the immune system in SLE. This review will introduce recent studies on how ncRNAs are involved in the development of SLE.

RECENT FINDINGS

Recent advances in ncRNAs biology have greatly expanded our understanding of epigenetic regulation of immune responses and inflammation, and increasing evidence suggests ncRNAs are important players in SLE development. Identifications of abnormal expression patterns of ncRNAs and relevant biological impacts in lupus patients have revealed their potential as novel biomarkers and therapeutic targets for SLE. The dysregulation of ncRNAs contributes to the immunopathogenesis of SLE. Clarifying the functions and mechanisms of SLE-associated ncRNAs provides new opportunities for disease biomarkers and targeted therapies.

Host miRNA and immune cell interactions: relevance in nano-therapeutics for human health

Around 2200 miRNA (microRNA) genes were found in the human genome. miRNAs are arranged in clusters within the genome and share the same transcriptional regulatory units. It has been revealed that approximately 50% of miRNAs elucidated in the genome are transcribed from non-protein-coding genes, and the leftover miRNAs are present in the introns of coding sequences. We are now approaching a stage in which miRNA diagnostics and therapies can be established confidently, and several commercial efforts are underway to carry these innovations from the bench to the clinic. MiRNAs control many of the significant cellular activities such as production, differentiation, growth, and metabolism. Particularly in the immune system, miRNAs have emerged as a crucial biological component during diseased state and homeostasis. miRNAs have been found to regulate inflammatory responses and autoimmune disorders. Moreover, each miRNA targets multiple genes simultaneously, making miRNAs promising tools as diagnostic biomarkers and as remedial targets. Still, one of the major obstacles in miRNA-based approaches is the achievement of specific and efficient systemic delivery of miRNAs. To overcome these challenges, nanoformulations have been synthesized to protect miRNAs from degradation and enhance cellular uptake. The current review deals with the miRNA-mediated regulation of the recruitment and activation of immune cells, especially in the tumor microenvironment, viral infection, inflammation, and autoimmunity. The nano-based miRNA delivery modes are also discussed here, especially in the context of immune modulation.

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.

Epigenetic linkage of systemic lupus erythematosus and nutrition

The term "epigenetics" refers to a series of meiotically/mitotically inheritable alterations in gene expression, related to environmental factors, without disruption on DNA sequences of bases. Recently, the pathophysiology of autoimmune diseases (ADs) has been closely linked to epigenetic modifications. Actually, epigenetic mechanisms can modulate gene expression or repression of targeted cells and tissues involved in autoimmune/inflammatory conditions acting as keys effectors in regulation of adaptive and innate responses. ADs, as systemic lupus erythematosus (SLE), a rare disease that still lacks effective treatment, is characterized by epigenetic marks in affected cells.Taking into account that epigenetic mechanisms have been proposed as a winning strategy in the search of new more specific and personalized therapeutics agents. Thus, pharmacology and pharmacoepigenetic studies about epigenetic regulations of ADs may provide novel individualized therapies. Focussing in possible implicated factors on development and predisposition of SLE, diet is feasibly one of the most important factors since it is linked directly to epigenetic alterations and these epigenetic changes may augment or diminish the risk of SLE. Nevertheless, several studies have guaranteed that dietary therapy could be a promise to SLE patients via prophylactic actions deprived of side effects of pharmacology, decreasing co-morbidities and improving lifestyle of SLE sufferers.Herein, we review and discuss the cross-link between epigenetic mechanisms on SLE predisposition and development, as well as the influence of dietary factors on regulation epigenetic modifications that would eventually make a positive impact on SLE patients.

Can altered colostrum miRNA expression profile after cesarean delivery be a risk factor for autoimmune diseases?

PROBLEM

The cesarean section (CS) rate has increased significantly in North America, Western Europe, and Latin America. However, it has been reported that the incidence of inflammatory and autoimmune diseases such as asthma and type 1 diabetes increased in parallel with CS in these countries. Our aim was to investigate the expression level of miRNAs associated with inflammatory response and autoimmune diseases in colostrum samples and contribute to elucidating the role of CS in the pathogenesis of immune system-related diseases.

METHOD OF STUDY

Colostrum samples were taken from voluntary mothers who had 40 normal and 50 cesarean births. miRNAs were extracted from colostrums and detected to miRNA expression profiling (eighty-four miRNAs) by quantitative real-time PCR with the Fluidigm integrated microfluidic circuit technology.

RESULTS

There was a statistically significant change in the expression levels of 17 miRNAs in the colostrums of mothers who had normal and cesarean delivery (p < .05), and all of miRNAs were upregulated in the colostrums of mothers who have had cesarean delivery.

CONCLUSION

Our best knowledge is that the study we conducted was the first to investigate the effect of delivery method (CS or normal) on the miRNA profile of colostrum. Cesarean delivery is a potential risk factor for inflammatory and immune system-related diseases in children due to dysregulation in miRNA expression.

Epigenetic Contribution and Genomic Imprinting Dlk1-Dio3 miRNAs in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease that afflicts multiple organs, especially kidneys and joints. In addition to genetic predisposition, it is now evident that DNA methylation and microRNAs (miRNAs), the two major epigenetic modifications, are critically involved in the pathogenesis of SLE. DNA methylation regulates promoter accessibility and gene expression at the transcriptional level by adding a methyl group to 5' cytosine within a CpG dinucleotide. Extensive evidence now supports the importance of DNA hypomethylation in SLE etiology. miRNAs are small, non-protein coding RNAs that play a critical role in the regulation of genome expression. Various studies have identified the signature lupus-related miRNAs and their functional contribution to lupus incidence and progression. In this review, the mutual interaction between DNA methylation and miRNAs regulation in SLE is discussed. Some lupus-associated miRNAs regulate DNA methylation status by targeting the DNA methylation enzymes or methylation pathway-related proteins. On the other hand, DNA hyper- and hypo-methylation are linked with dysregulated miRNAs expression in lupus. Further, we specifically discuss the genetic imprinting Dlk1-Dio3 miRNAs that are subjected to DNA methylation regulation and are dysregulated in several autoimmune diseases, including SLE.

Downregulation of miR-125a-5p and miR-218-5p in Peripheral Blood Mononuclear Cells of Patients with Relapsing-Remitting Multiple Sclerosis

Multiple sclerosis (MS) is a chronic neuroinflammatory disease of the brain and spinal cord. Evidences have demonstrated that microRNAs (miRNAs) are involved in the pathological process of MS that may confer a valuable diagnostic biomarker for disease diagnosis, prognosis, and treatment. Hence, we assessed the expression pattern of miR-125a-5p and miR-218-5p in the peripheral blood mononuclear cells (PBMCs) of subjects with relapsing-remitting multiple sclerosis (RRMS). We recruited 50 RRMS patients and 50 age- and sex-matched healthy control subjects. PBMCs were isolated from the peripheral blood samples, RNA content was extracted, cDNA was synthesized, and finally expression level of miRNAs was determined using quantitative real-time PCR. Our data indicate significant downregulation of both miR-125a-5p and miR-218-5p in RRMS patients compared to healthy controls (P< .0001). The levels of both miRNAs were significantly downregulated in an age-dependent manner compared with consistent healthy control groups (30-40 years old P< .0001). Expression level of miR-218-5p was significantly changed in only female patients (Female group P< .0001; Male group P= .12). Receiver operating characteristic (ROC) curve data indicated that the expression levels of both miRNAs were able to discriminate RRMS patients from healthy subjects (P< .05). Moreover, bioinformatic enrichment analysis revealed that the target genes of these miRNAs had cardinal roles in the regulation of key biological pathways involved in the clinical course and pathogenesis of MS. Collectively, our results suggested that miR-125a-5p and miR-218-5p play a role in RRMS pathogenesis and have an age- and sex-dependent expression pattern in these patients.

Association of microRNA-125a with the clinical features, disease activity and inflammatory cytokines of juvenile-onset lupus patients

BACKGROUND

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with marked variation in its clinical presentation. Juvenile-onset SLE (jSLE) exhibits an aggressive clinical phenotype and severe complications. Dysregulated expression of microRNAs (miRs) in immune cells from patients with SLE has been found. We aim to evaluate the association of miR-125a with the clinical and laboratory characteristics, disease activity and inflammatory cytokines of jSLE patients.

METHODS

60 jSLE patients and 25 normal controls were involved in the study. The expression pattern of miR-125a was determined in plasma of all subjects using qRT-PCR. In addition, plasma levels of IL-17 and IFN-γ were examined using ELISA. The correlation of miR-125a expression with the clinical manifestations and disease activity of jSLE patients was analyzed. Also, its association with the inflammatory cytokines was investigated in jSLE patients.

RESULTS

Our findings showed that miR-125a expression levels were significantly reduced in jSLE patients compared to normal controls (p < 0.01) and these expression levels differed based on the clinical variability of patients. In addition, plasma levels of IL-17 and IFN-γ in jSLE patients were significantly higher than healthy controls (p < 0.01). Finally, miR-125a expression had significant negative associations with each of SLEDAI-2K (p < 0.01), SLICC (p < 0.01), ESR (p < 0.05), proteinuria (p < 0.01) and IL-17 levels (p < 0.01) in jSLE patients.

CONCLUSION

Our findings postulate that miR-125a could act as a candidate therapeutic target for its possible regulation of inflammation in jSLE patients.

The identification of circular RNAs from peripheral blood mononuclear cells in systemic lupus erythematosus

Background

The diagnosis of systemic lupus erythematosus (SLE) is complicated. This study explores the expression of circular RNAs (circRNAs), which are closed non-coding RNAs in which the 5′ and 3′ ends are covalently linked and which work by sponging microRNAs. CircRNAs were extracted from peripheral blood mononuclear cells (PBMCs) of SLE patients to identify novel circRNA species that might be used for SLE diagnosis.

Methods

Microarray was applied to screening circRNAs changes in PBMCs obtained from SLE patients (n = 10) and healthy participants (n = 10), paired for age and sex. We then verified the selected circRNAs in PBMCs using quantitative reverse transcription-polymerase chain reaction amplification (qRT-PCR) in another cohort, including ten paired SLE patients and healthy participants. The correlation between the differential circRNAs and clinical pathology of SLE were analyzed.

Results

182 up-regulated and 563 significantly down-regulated circRNAs in PBMCs of patients with SLE were identified. Besides, the qRT-PCR results were consistent with the microarray results. The correlation analysis revealed that has_circRNA_100236, has_circRNA_102489, and has_circRNA_101413 were correlated with positive anti-dsDNA, thrombocytopenia, and positive IgG, respectively. Lastly, their miRNAs targets and the binding sites were predicted.

Conclusion

We identified some dysregulated circRNAs in PBMCs from SLE patients, and these circRNAs may be developed as the novel biomarkers for the diagnosis of SLE.

Epigenetics in Non-tumor Immune-Mediated Skin Diseases

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

Genetic and molecular biology of systemic lupus erythematosus among Iranian patients: an overview

BACKGROUND

Systemic lupus erythematosus (SLE) is a clinicopathologically heterogeneous chronic autoimmune disorder affecting different organs and tissues. It has been reported that there is an increasing rate of SLE incidence among Iranian population. Moreover, the Iranian SLE patients have more severe clinical manifestations compared with other countries. Therefore, it is required to introduce novel methods for the early detection of SLE in this population. Various environmental and genetic factors are involved in SLE progression.

MAIN BODY

In present review we have summarized all of the reported genes which have been associated with clinicopathological features of SLE among Iranian patients.

CONCLUSIONS

Apart from the reported cytokines and chemokines, it was interestingly observed that the apoptosis related genes and non-coding RNAs were the most reported genetic abnormalities associated with SLE progression among Iranians. This review clarifies the genetics and molecular biology of SLE progression among Iranian cases. Moreover, this review paves the way of introducing an efficient panel of genetic markers for the early detection and better management of SLE in this population.

Upregulation of MicroRNA-125b Leads to the Resistance to Inflammatory Injury in Endothelial Progenitor Cells

Objectives

MicroRNA-125b (miR-125b) has been recognized as one of the key regulators of the inflammatory responses in cardiovascular diseases recently. This study sought to dissect the role of miR-125b in modulating the function of endothelial progenitor cells (EPCs) in the inflammatory environment of ischemic hearts.

Methods

EPCs were cultured and transfected with miR-125b mimic and negative control mimic. Cell migration and adhesion assays were performed after tumor necrosis factor-α (TNF-α) treatment to determine EPC function. Cell apoptosis was analyzed by flow cytometry. The activation of the NF-κB pathway was measured by western blotting. EPC-mediated neovascularization in vivo was studied by using a myocardial infarction model.

Results

miR-125b-overexpressed EPCs displayed improved cell migration, adhesion abilities, and reduced cell apoptosis compared with those of the NC group after TNF-α treatment. miR-125b overexpression in EPCs ameliorated TNF-α-induced activation of the NF-κB pathway. Mice transplanted with miR-125b-overexpressed EPCs showed improved cardiac function recovery and capillary vessel density than the ones transplanted with NC EPCs.

Conclusions

miR-125b protects EPCs against TNF-α-induced inflammation and cell apoptosis by attenuating the activation of NF-κB pathway and consequently improves the cardiac function recovery and EPC-mediated neovascularization in the ischemic hearts.

Discovering the signature of a lupus-related microRNA profile in the Gene Expression Omnibus repository

Lupus is one of the most prevalent systemic autoimmune diseases. It is a multifactorial disease in which genetic, epigenetic and environmental factors play significant roles. The pathogenesis of lupus is not yet well understood. However, deregulation of microRNAs (miRNAs) - one of the post-transcriptional regulators of genes - can contribute to the development of autoimmune diseases. Over the last two decades, advances in the profiling of miRNA using microarray have received much attention, and it has been demonstrated that miRNAs play a regulatory role in the pathogenesis of lupus. Therefore, dysregulated miRNAs can be considered as promising diagnostic biomarkers for lupus. This article is an overview of lupus-related miRNA profiling studies and arrays in the Gene Expression Omnibus (GEO) database. The aims of our study were to widen current knowledge of known dysregulated miRNAs as potential biomarkers of SLE and to introduce a bioinformatics approach to using microarray data and finding novel miRNA and gene candidates for further study. We identified hsa-miR-4709-5p, hsa-miR-140, hsa-miR-145, hsa-miR-659, hsa-miR-134, hsa-miR-150, hsa-miR-584, hsa-miR-409 and hsa-miR-152 as potential biomarkers by integrated bioinformatics analysis.

Exploring the Role of Non-Coding RNAs in the Pathophysiology of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic immune-related disorder designated by a lack of tolerance to self-antigens and the over-secretion of autoantibodies against several cellular compartments. Although the exact pathophysiology of SLE has not been clarified yet, this disorder has a strong genetic component based on the results of familial aggregation and twin studies. Variation in the expression of non-coding RNAs has been shown to influence both susceptibility to SLE and the clinical course of this disorder. Several long non-coding RNAs (lncRNAs) such as GAS5, MALAT1 and NEAT1 are dysregulated in SLE patients. Moreover, genetic variants within lncRNAs such as SLEAR and linc00513 have been associated with risk of this disorder. The dysregulation of a number of lncRNAs in the peripheral blood of SLE patients has potentiated them as biomarkers for diagnosis, disease activity and therapeutic response. MicroRNAs (miRNAs) have also been shown to affect apoptosis and the function of immune cells. Taken together, there is a compelling rationale for the better understanding of the involvement of these two classes of non-coding RNAs in the pathogenesis of SLE. Clarification of the function of these transcripts has the potential to elucidate the molecular pathophysiology of SLE and provide new opportunities for the development of targeted therapies for this disorder.

Long non-coding RNA ANRIL knockdown suppresses apoptosis and pro-inflammatory cytokines while enhancing neurite outgrowth via binding microRNA-125a in a cellular model of Alzheimer's disease

The present study aimed to investigate the effect of the long non-coding RNA antisense non-coding RNA in the INK4 locus (lnc-ANRIL) knockdown on apoptosis, neurite outgrowth and inflammation based on a PC12 cellular Alzheimer's disease (AD) model. A cellular AD model was constructed by treating nerve growth factor stimulated PC12 cells with amyloid β (Aβ) 1–42 and then control knockdown plasmid and lnc-ANRIL knockdown plasmid were transfected in the PC12 cellular AD model as the KD- negative control (NC) group or the AD-ANRIL group respectively. Apoptosis, neurite outgrowth, pro-inflammatory cytokines and microRNA (miR)-125a were assessed. Rescue experiments were conducted by transfecting lnc-ANRIL knockdown plasmid and lnc-ANRIL knockdown plasmid and miR-125a inhibitor in the PC12 cellular AD model as the KD-ANRIL group or KD-ANRIL + KD-miR-125a group respectively. Following transfection, cell apoptosis deccreased while neurite outgrowth increased in the KD-ANRIL group compared with the KD-NC group (all P<0.01). Concerning inflammation, tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β, IL-6 and IL-17 were decreased in the KD-ANRIL group compared with the KD-NC group (all P<0.01). miR-125a was negatively regulated by lnc-ANRIL and therefore rescue experiments were subsequently conducted. In the rescue experiments, cell apoptosis was increased while total neurite outgrowth was inhibited in the KD-ANRIL + KD-miR-125a group compared with the KD-ANRIL group (all P<0.01), and TNF-α, IL-1β, IL-6 and IL-17 were increased in the KD-ANRIL + KD-miR-125a group compared with the KD-ANRIL group (all P<0.01). A luciferase reporter assay demonstrated that lnc-ANRIL directly bound miR-125a. lnc-ANRIL knockdown suppressed cell apoptosis and inflammation while promoting neurite outgrowth via binding of miR-125a in AD.

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.

Autoimmunity and organ damage in systemic lupus erythematosus

Impressive progress has been made over the last several years toward understanding how almost every aspect of the immune system contributes to the expression of systemic autoimmunity. In parallel, studies have shed light on the mechanisms that contribute to organ inflammation and damage. New approaches that address the complicated interaction between genetic variants, epigenetic processes, sex and the environment promise to enlighten the multitude of pathways that lead to what is clinically defined as systemic lupus erythematosus. It is expected that each patient owns a unique 'interactome', which will dictate specific treatment.

Role of microRNAs in the Development of Cardiovascular Disease in Systemic Autoimmune Disorders

Rheumatoid Arthritis (RA), Systemic lupus erythematosus (SLE) and antiphospholipid syndrome (APS) are the systemic autoimmune diseases (SADs) most associated with an increased risk of developing cardiovascular (CV) events. Cardiovascular disease (CVD) in SADs results from a complex interaction between traditional CV-risk factors, immune deregulation and disease activity. Oxidative stress, dyslipidemia, endothelial dysfunction, inflammatory/prothrombotic mediators (cytokines/chemokines, adipokines, proteases, adhesion-receptors, NETosis-derived-products, and intracellular-signaling molecules) have been implicated in these vascular pathologies. Genetic and genomic analyses further allowed the identification of signatures explaining the pro-atherothrombotic profiles in RA, SLE and APS. However, gene modulation has left significant gaps in our understanding of CV co-morbidities in SADs. MicroRNAs (miRNAs) are emerging as key post-transcriptional regulators of a suite of signaling pathways and pathophysiological effects. Abnormalities in high number of miRNA and their associated functions have been described in several SADs, suggesting their involvement in the development of atherosclerosis and thrombosis in the setting of RA, SLE and APS. This review focusses on recent insights into the potential role of miRNAs both, as clinical biomarkers of atherosclerosis and thrombosis in SADs, and as therapeutic targets in the regulation of the most influential processes that govern those disorders, highlighting the potential diagnostic and therapeutic properties of miRNAs in the management of CVD.

The epigenetic face of lupus: Focus on antigen-presenting cells

In recent years, epigenetic mechanisms became widely known due to their ability to regulate and maintain physiological processes such as cell growth, development, differentiation and genomic stability. When dysregulated, epigenetic mechanisms, may introduce gene expression changes and disturbance in immune homeostasis leading to autoimmune diseases. Systemic lupus erythematosus (SLE), the most extensively studied autoimmune disorder, has already been correlated with epigenetic modifications, especially in T cells. Since these cell rely on antigen presentation, it may be assumed that erroneous activity of antigen-presenting cells (APCs), culminates in T cell abnormalities. In this review we summarize and discuss the epigenetic modifications in SLE affected APCs, with the focus on dendritic cells (DCs), B cells and monocytes. Unravelling this aspect of SLE pathogenesis, might result in identification of new disease biomarkers and putative therapeutic approaches.

Measurement of circulating miRNA-125a exhibits good value in the management of etanercept-treated psoriatic patients

This study aimed to explore the correlation of miR-125a with risk and severity of psoriasis, and further investigate the potential of miR-125a for predicting response to etanercept (ETN) treatment in psoriatic patients. Moderate to severe plaque psoriatic patients (n = 126) about to undergo ETN treatment for 6 months were recruited. Their plasma samples were obtained, and Psoriasis Area and Severity Index (PASI) scores and PASI-75 response rate were assessed at baseline (M0), and at 1 (M1), 3 (M3) and 6 months (M6) of treatment. Referring to PASI-75 response status at M6, patients were categorized as PASI-75 responders and PASI-75 non-responders. Healthy controls (HC, n =120) were also enrolled and their plasma samples were collected. In addition, plasma miR-125a was determined by quantitative polymerase chain reaction. miR-125a was decreased in psoriatic patients compared with HC; further, the receiver-operator curve (ROC) exhibited that miR-125a was of good value in differentiating psoriatic patients from HC with an area under the curve (AUC) of 0.802. In psoriatic patients, miR-125a was negatively associated with PASI score to some extent. Interestingly, baseline miR-125a was lower in PASI-75 responders than PASI-75 non-responders; further, ROC showed it predicted PASI-75 response at M6 to some extent with AUC of 0.672. Multivariate logistic regression also revealed that miR-125a was an independent predictive factor for worse PASI-75 response at M6. Furthermore, miR-125a expression was gradually increased during the treatment in PASI-75 responders, but unchanged in PASI-75 non-responders. Measurement of circulating miR-125a exhibits good value in the management of ETN-treated psoriatic patients.

MiR-125a-5p Regulates Vitamin D Receptor Expression in a Mouse Model of Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is a chronic and incurable autoimmune neurodegenerative disease of the central nervous system. Although the symptoms of MS can be managed by vitamin D3 treatment alone, this condition cannot be completely eradicated. Thus, there might be unknown factors capable of regulating the vitamin D receptor (VDR). Genome-wide analysis showed that miRNAs were associated with VDRs. We sought to determine the role and mechanism of action of miRNA-125a-5p and VDRs in a model of MS, mice with experimental autoimmune encephalomyelitis (EAE), which was induced by myelin oligodendrocyte glycoprotein 35-55 peptides. EAE mice showed decreased mean body weight but increased mean clinical scores compared with vehicle or control mice. And inflammatory infiltration was found in the lumbosacral spinal cord of EAE mice. In addition, VDR expression was significantly lower while the expression of miR-125a-5p was markedly higher in the spinal ventral horn of EAE mice than in vehicle or control mice. Importantly, activation of VDRs by paricalcitol or inhibition of miR-125a-5p by its antagomir markedly decreased the mean clinical scores in EAE mice. Interestingly, VDR and miR-125a-5p were co-localized in the same neurons of the ventral horn. More importantly, inhibition of miR-125a-5p remarkably blocked the decrease of VDRs in EAE mice. These results support a critical role for miR-125a-5p in modulating VDR activity in EAE and suggest potential novel therapeutic interventions.

Integrated analysis of microRNA regulation and its interaction with mechanisms of epigenetic regulation in the etiology of systemic lupus erythematosus

The aim of this study was to identity in silico the relationships among microRNAs (miRNAs) and genes encoding transcription factors, ubiquitylation, DNA methylation, and histone modifications in systemic lupus erythematosus (SLE). To identify miRNA dysregulation in SLE, we used miR2Disease and PhenomiR for information about miRNAs exhibiting differential regulation in disease and other biological processes, and HMDD for information about experimentally supported human miRNA–disease association data from genetics, epigenetics, circulating miRNAs, and miRNA–target interactions. This information was incorporated into the miRNA analysis. High-throughput sequencing revealed circulating miRNAs associated with kidney damage in patients with SLE. As the main finding of our in silico analysis of miRNAs differentially expressed in SLE and their interactions with disease-susceptibility genes, post-translational modifications, and transcription factors; we highlight 226 miRNAs associated with genes and processes. Moreover, we highlight that alterations of miRNAs such as hsa-miR-30a-5p, hsa-miR-16-5p, hsa-miR-142-5p, and hsa-miR-324-3p are most commonly associated with post-translational modifications. In addition, altered miRNAs that are most frequently associated with susceptibility-related genes are hsa-miR-16-5p, hsa-miR-374a-5p, hsa-miR-34a-5p, hsa-miR-31-5p, and hsa-miR-1-3p.

Taenia crassiceps-Excreted/Secreted Products Induce a Defined MicroRNA Profile that Modulates Inflammatory Properties of Macrophages

Helminth parasites modulate immune responses in their host to prevent their elimination and to establish chronic infections. Our previous studies indicate that Taenia crassiceps-excreted/secreted antigens (TcES) downregulate inflammatory responses in rodent models of autoimmune diseases, by promoting the generation of alternatively activated-like macrophages (M2) in vivo. However, the molecular mechanisms triggered by TcES that modulate macrophage polarization and inflammatory response remain unclear. Here, we found that, while TcES reduced the production of inflammatory cytokines (IL-6, IL-12, and TNFα), they increased the release of IL-10 in LPS-induced bone marrow-derived macrophages (BMDM). However, TcES alone or in combination with LPS or IL-4 failed to increase the production of the canonical M1 or M2 markers in BMDM. To further define the anti-inflammatory effect of TcES in the response of LPS-stimulated macrophages, we performed transcriptomic array analyses of mRNA and microRNA to evaluate their levels. Although the addition of TcES to LPS-stimulated BMDM induced modest changes in the inflammatory mRNA profile, it induced the production of mRNAs associated with the activation of different receptors, phagocytosis, and M2-like phenotype. Moreover, we found that TcES induced upregulation of specific microRNAs, including miR-125a-5p, miR-762, and miR-484, which are predicted to target canonical inflammatory molecules and pathways in LPS-induced BMDM. These results suggest that TcES can modulate proinflammatory responses in macrophages by inducing regulatory posttranscriptional mechanisms and hence reduce detrimental outcomes in hosts running with inflammatory diseases.

Circular RNAS: novel biomarkers of disease activity in systemic lupus erythematosus?

Circular RNAs (circRNAs) are a class of non-coding RNAs that regulate gene expression by acting as competitive endogenous RNAs (ceRNAs) and modulating gene transcription. Several studies support the implication of circRNAs in a variety of human diseases, but research on the role of circRNAs in systemic lupus erythematosus (SLE) is lacking. In a study recently published in Clinical Science (2018), Zhang et al. identified hsa_circ_0012919 as a potential biomarker of disease activity in SLE patients. The authors observed different circRNA expression between SLE patients and healthy controls, an association with clinical variables and with the abnormal DNA methylation present in SLE CD4⁺ T cells. Finally, Zhang et al. demonstrated that hsa_circ_0012919 acts as a miRNA sponge for miR-125a-3p, regulating the gene expression of targets RANTES and KLF13 that are involved in the physiology and pathophysiology of acute and chronic inflammatory processes. These findings support the role of circRNAs in the pathophysiology of SLE.

New Biomarkers for Atherothrombosis in Antiphospholipid Syndrome: Genomics and Epigenetics Approaches

Antiphospholipid Syndrome (APS) is an autoimmune disorder, characterized by pregnancy morbidity and/or a hyper coagulable state involving the venous or the arterial vasculature and associated with antiphospholipid antibodies (aPL), including anti-cardiolipin antibodies (aCL), anti-beta2-glycoprotein I (anti-ß2GPI), and Lupus anticoagulant (LA). In recent years there have been many advances in the understanding of the molecular basis of vascular involvement in APS. APS is of multifactorial origin and develops in genetically predisposed individuals. The susceptibility is determined by major histocompatibility complex (MHC). Different HLA-DR and HLA-DQ alleles have been reported in association with APS. Moreover, MHC II alleles may determine the autoantibody profile and, as such, the clinical phenotype of this disease. Besides, polymorphisms in genes related to the vascular system are considered relevant factors predisposing to clinical manifestations. Antiphospholipid antibodies (aPL) induce genomic and epigenetic alterations that support a pro- thrombotic state. Thus, a specific gene profile has been identified in monocytes from APS patients -related to aPL titres in vivo and promoted in vitro by aPL- explaining their cardiovascular involvement. Regarding epigenetic approaches, we previously recognized two miRNAs (miR-19b/miR-20a) as potential modulators of tissue factor, the main receptor involved in thrombosis development in APS. aPLs can further promote changes in the expression of miRNA biogenesis proteins in leukocytes of APS patients, which are translated into an altered miRNA profile and, consequently, in the altered expression of their protein targets related to thrombosis and atherosclerosis. MicroRNAs are further released into the circulation, acting as intercellular communicators. Accordingly, a specific signature of circulating miRNAs has been recently identified in APS patients as potential biomarkers of clinical features. Genomics and epigenetic biomarkers might also serve as indices for disease progression, clinical pharmacology, or safety, so that they might be used to individually predict disease outcome and guide therapeutic decisions. In that way, in the setting of a clinical trial, novel and specific microRNA–mRNA regulatory networks in APS, modified by effect of Ubiquinol treatment, have been identified. In this review, current and previous studies analyzing genomic/epigenetic changes related to the clinical profile of APS patients, and their modulation by effect of specific therapies, are discussed.

Regulating IRFs in IFN Driven Disease

The Interferon regulatory factors (IRFs) are a family of transcription factors that play pivotal roles in many aspects of the immune response, including immune cell development and differentiation and regulating responses to pathogens. Three family members, IRF3, IRF5, and IRF7, are critical to production of type I interferons downstream of pathogen recognition receptors that detect viral RNA and DNA. A fourth family member, IRF9, regulates interferon-driven gene expression. In addition, IRF4, IRF8, and IRF5 regulate myeloid cell development and phenotype, thus playing important roles in regulating inflammatory responses. Thus, understanding how their levels and activity is regulated is of critical importance given that perturbations in either can result in dysregulated immune responses and potential autoimmune disease. This review will focus the role of IRF family members in regulating type I IFN production and responses and myeloid cell development or differentiation, with particular emphasis on how regulation of their levels and activity by ubiquitination and microRNAs may impact autoimmune disease.

Triptolide ameliorates lupus via the induction of miR-125a-5p mediating Treg upregulation

Triptolide is a biologically active component of the Chinese antirheumatic herbal remedy Tripterygium wilfordii Hook F, which has been shown to be effective in treating murine lupus. However, its immunological mechanisms are poorly understood. Regulatory T cells (Treg) are pivotal for maintaining peripheral self-tolerance and controlling autoimmunity. This study was undertaken to examine the therapeutic effect of triptolide in lupus mice and the related molecular mechanisms. Our results showed that triptolide treatment ameliorated serum anti-dsDNA, proteinuria and renal histopathologic assessment in MRL/lpr mice, induced the miR-125a-5p expression and enhanced the proportion of Treg in vivo. In vitro, triptolide upregulated the proportion of Treg and the miR-125a-5p expression. Down-regulation of the miR-125a-5p expression reversed the effect of triptolide on Treg. In conclusion, triptolide could induce Treg and the miR-125a-5p expression in vivo and in vitro. Inhibiting the effect of miR-125a-5p could counteract the effect of triptolide on inducing Treg. The study has strong implications for the therapeutic applications of triptolide in systemic lupus erythematosus.

Downregulation of KLF13 through DNMT1-mediated hypermethylation promotes glioma cell proliferation and invasion

Background

Recent evidence indicates that Kruppel-like factor 13 (KLF13) has critical roles in regulating cell differentiation, proliferation and may function as a tumor suppressor. However, its role in glioma progression is poorly understood.

Methods

Public database was used to explore the expression and prognostic value of KLF13 in glioma. Cell proliferation and invasion assays were used to explore the role of KLF13. Bisulfite sequencing and ChIP assay were used to determine the methylation of KLF13 promoter in glioma and the regulation of KLF13 by DNMT1.

Results

We found that KLF13 inhibited glioma cell proliferation and invasion, which could be reversed by AKT activation. DNMT1-mediated hypermethylation was responsible for downregulation of KLF13. Knocking down of DNMT1 restored KFL13 expression and inhibited cell proliferation and invasion as well. Patients with high expression of KLF13 might have a better prognosis.

Conclusion

KLF13 suppressed glioma aggressiveness and the regulation of KLF13 could be a potential therapeutic target.

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.

Microarray expression profile of circular RNAs and mRNAs in children with systemic lupus erythematosus

BACKGROUND

Recently, it was reported that circular RNAs (circRNAs) play the crucial role in many physiological and biological processes and can be used as biomarkers. However, the information about circRNAs in children with systemic lupus erythematosus (SLE) is limited. The aim of this study is to determine the expression of circRNAs in children with SLE and investigate the significance of circRNA for diagnosing SLE.

METHODS

Microarray profile of circRNAs and mRNAs was performed for identifying the changes in expression of circRNAs and mRNAs between children with SLE and healthy children. Quantitative polymerase chain reaction (qPCR) was used to confirm the results. Spearman correlation test was performed to assess the correlation between circRNAs and clinical variables. The receiver operating characteristic (ROC) curve was calculated for evaluating the diagnostic value.

RESULTS

A comparison between the children with SLE and healthy children revealed that 348 circRNAs and 1162 mRNAs were expressed differentially. The authors constructed a complex circRNA target network consisting of 307 matched circRNA-mRNA pairs for 124 differentially expressed circRNAs (74 circRNAs were upregulated, and 50 circRNAs were downregulated) and 142 differentially expressed mRNAs (83 mRNAs were upregulated, and 59 mRNAs were downregulated) by using gene co-expression network analysis. The competing for endogenous RNA (ceRNA) network includes 42 differentially expressed circRNAs, 41 differentially expressed mRNAs, and 71 predicted miRNAs. Among these SLE patients, we detected that the hsa_circ_0021372 and hsa_circ_0075699 levels are associated with C3 and C4 levels in children with SLE. The hsa_circ_0057762 level is positively associated with the SLEDAI-2K score. The ROC curves of circRNAs showed that the levels of hsa_circ_0057762 (AUC 0.804, 95% CI 0.607-1.0, P = 0.02) and hsa_circ_0003090 (AUC 0.848, 95% CI 0.688-1.0, P = 0.008) could differentiate the patients with SLE from the healthy controls.

CONCLUSIONS

We firstly characterized the expression profiles of circRNA and mRNA in children with SLE and propose herein their possible roles in the pathogenesis of SLE. These results provide novel insight into the mechanisms of SLE pathogenesis, and circRNAs may serve as useful biomarkers for SLE.

Circulating microRNAs as potential biomarkers of disease activity and structural damage in ankylosing spondylitis patients

Ankylosing spondylitis (AS) remains difficult to diagnose before irreversible damage to sacroiliac joint is noticeable. Circulating microRNAs have demonstrated to serve as diagnostic tools for several human diseases. Here, we analysed plasma microRNAs to identify potential AS biomarkers. Higher expression levels of microRNA (miR)-146a-5p, miR-125a-5p, miR-151a-3p and miR-22-3p, and lower expression of miR-150-5p, and miR-451a were found in AS versus healthy donors. Interestingly, higher miR-146a-5p, miR-125a-5p, miR-151a-3p, miR-22-3p and miR-451a expression was also observed in AS than psoriatic arthritis patients. The areas under the curve, generated to assess the accuracy of microRNAs as diagnostic biomarkers for AS, ranged from 0.614 to 0.781; the six-microRNA signature reached 0.957. Bioinformatics analysis revealed that microRNAs targeted inflammatory and bone remodeling genes, underlying their potential role in this pathology. Indeed, additional studies revealed an association between these six microRNAs and potential target proteins related to AS pathophysiology. Furthermore, miR-146a-5p, miR-125a-5p and miR-22-3p expression was increased in active versus non-active patients. Moreover, miR-125a-5p, miR-151a-3p, miR-150-5p and miR-451a expression was related to the presence of syndesmophytes in AS patients. Overall, this study identified a six-plasma microRNA signature that could be attractive candidates as non-invasive biomarkers for the AS diagnosis, and may help to elucidate the disease pathogenesis.

NovelmiRNA-25 inhibits AMPD2 in peripheral blood mononuclear cells of patients with systemic lupus erythematosus and represents a promising novel biomarker

Background

Systemic lupus erythematosus (SLE) is a multisystemic autoimmune disease with various clinical manifestations. MicroRNAs (miRNAs) and immunometabolism are recognized as key elements in SLE pathogenesis; however, the relationship between miRNAs in peripheral blood mononuclear cells (PBMCs) and metabolism in SLE remains unclear.

Methods

We detected PBMC miRNA and mRNA profiles from 3 pooled SLE patients and 3 healthy controls (HCs) using next-generation sequencing, predicted miRNA targets in dysregulated mRNAs, predicted functions and interactions of differentially expressed genes using bioinformatics analysis, validated candidate miRNAs using qRT-PCR, and investigated the association between the expression of candidate miRNAs and SLE clinical characteristics. Moreover, we validated the direct and transcriptional regulatory effect of NovelmiRNA-25 on adenosine monophosphate deaminase 2 (AMPD2) using a dual-luciferase reporter assay and western blot and confirmed AMPD2 mRNA and protein expression in PBMCs using qRT-PCR and western blot, respectively.

Results

Multilayer integrative analysis of microRNA and mRNA regulation showed that 10 miRNAs were down-regulated and 19 miRNAs were up-regulated in SLE patient PBMCs compared with HCs. Bioinformatics analysis of regulatory networks between miRNAs and mRNAs showed that 19 miRNAs were related to metabolic processes. Two candidate miRNAs, NovelmiRNA-25 and miR-1273h-5p, which were significantly increased in the PBMCs of SLE patients (P < 0.05), represented diagnostic biomarkers with sensitivities of 94.74% and 89.47%, respectively (area under the curve = 0.574 and 0.788, respectively). NovelmiRNA-25 expression in PBMCs was associated with disease activity in SLE patients, in both active and stable groups (P < 0.05). NovelmiRNA-25 overexpression downregulated AMPD2 expression in HEK293T cells through direct targeting of the AMPD2 3ʹUTR (P < 0.01), while inhibition of NovelmiRNA-25 activity led to increased AMPD2 expression (P < 0.01). NovelmiRNA-25 overexpression also downregulated AMPD2 protein expression in HEK293T cells; AMPD2 protein expression in SLE patient PBMCs was decreased. Our results show that differentially expressed miRNAs play an important role in SLE.

Conclusions

Our data demonstrate a novel mechanism in SLE development that involves the targeting of AMPD2 expression by NovelmiRNA-25. miRNAs may serve as novel biomarkers for the diagnosis and evaluation of disease activity of SLE and represent potential therapeutic targets for this disease.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1739-5) contains supplementary material, which is available to authorized users.

The down-regulation of hsa_circ_0012919, the sponge for miR-125a-3p, contributes to DNA methylation of CD11a and CD70 in CD4+ T cells of systemic lupus erythematous

BACKGROUND

Systemic lupus erythematous (SLE) is an autoimmune disease characterized by the production of autoantibodies directed against various autoantigens. But the expression profiles and functions of circular RNAs (circRNAs) in SLE are still scarce.

OBJECTIVES

To explore the roles of circRNA in SLE and its potential diagnostic potential in SLE.

METHODS

SLE patients and healthy control subjects were recruited. CD4⁺ T cells were isolated, circRNA microarray analysis were used to screen for circRNA candidate in CD4⁺ T cells. Expression of DNMT1, CD11a and CD70, and methylation level of CD11a and CD70 were detected after transfecting hsa_circ_0012919-targetted siRNA. The network analysis of hsa_circ_0012919 was used by bioinformatics. Luciferase reporter assay and fluorescence in situ hybridization (FISH) assay were used for screening for which miRNAs could bind with hsa_circ_0012919.

RESULTS

Twelve circRNAs were up-regulated and two circRNAs were down-regulated in SLE patients group after circRNA microarray analysis. Hsa_circ_0012919 was further confirmed to be significantly different between healthy control and SLE patients (P<0.05) and associated with SLE characters (P<0.05). Down-regulation of hsa_circ_0012919 (i) increased the expression of DNMT1 and reduced the expression of CD70, CD11a, (ii) reversed the DNA hypomethylation of CD11a and CD70 in CD4⁺ T cells of SLE, but it could be reversed by down-regulation of DNMT1. Hsa_circ_0012919 regulated KLF13 and RANTES by miR-125a Conclusion: Hsa_circ_0012919 could be regarded as a biomarker for SLE and hsa_circ_0012919 was the competitive endogenous RNA (ceRNA) for miR-125a-3p.