MiR-338-5p Promotes Inflammatory Response of Fibroblast-Like Synoviocytes in Rheumatoid Arthritis via Targeting SPRY1

Network pharmacology and experimental validation methods to reveal the active compounds and hub targets of Curculigo orchioides Gaertn in rheumatoid arthritis

BACKGROUND

Rheumatoid arthritis (RA) is an autoimmune disease that can lead to joint destruction and deformity. Curculigo orchioides Gaertn (CO) was previously revealed to play a significant role in RA treatment. However, the main active ingredients and molecular mechanisms of CO in regulating RA are still unclear.

METHODS

The active ingredients of CO were obtained from the Traditional Chinese Medicine Systems Pharmacology database and published literature. The targets corresponding to these compounds and the targets linked to RA were collected from public databases. The "ingredient-target" and "protein-protein interaction" networks were constructed to screen the main active ingredients and hub targets of CO in the treatment of RA. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment assays were used to elucidate the potential pharmacological mechanism of CO in RA. Molecular docking was performed to detect the binding between the main active ingredients and hub targets. Collagen-induced arthritis rats were used to validate the hub targets of CO against RA.

RESULTS

Network pharmacological topology analysis showed that caffeine, 2,4-dichloro-5-methoxy-3-methylphenol, curculigoside, orcinol glucoside, and orcin were the main active ingredients of CO, and matrix metalloproteinase 9 (MMP9), transcription factor AP-1 (JUN), prostaglandin-endoperoxide synthase 2 (PTGS2), brain-derived neurotrophic factor, and receptor-type tyrosine-protein phosphatase C were the hub targets of CO for RA treatment. Molecular docking revealed that curculigoside and orcinol glucoside had effective binding potential with MMP9, JUN, and PTGS2, respectively. In vivo experiments demonstrated that CO alleviated RA symptoms and inhibited the expression of MMP9, JUN, and PTGS2 proteins.

CONCLUSIONS

Our study demonstrates the main active ingredients and potential targets of CO against RA, laying an experimental foundation for the development and application of CO as an anti-RA drug.

Circulating microRNAs in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a pathology characterized by chronic inflammation and skin lesions. The molecular basis of the inflammatory network remains unclear; however, since microRNAs (miRNAs) are involved in the modulation of inflammation, the composition of a micro-transcriptome RNA library using the blood of HS patients was analysed here. The total miRNA expression profiles of miRNAs from HS patients was assayed by real-time qPCR. Here, compared to healthy controls, miR-24-1-5p, miR-146a-5p, miR26a-5p, miR-206, miR338-3p, and miR-338-5p expression was found significantly different in HS. Knowing the significance of the miRNA mechanism in inflammatory and immune progression, we suggest that miRNA profiles found in HS patients can be significant in understanding the pathogenesis modality and establishing efficient biomarkers for HS early diagnosis. In particular, miR-338-5p was closely related to HS invasiveness and production of cytokines and was atypically overexpressed. miR-338-5p may represent a good promise as a non-invasive clinical biomarker for HS.

Bioinformatics Analysis Identified the Hub Genes, mRNA–miRNA–lncRNA Axis, and Signaling Pathways Involved in Rheumatoid Arthritis Pathogenesis

Objective

Rheumatoid arthritis (RA) is a nonspecific, chronic, systemic autoimmune disease characterized by symmetric polyarticular synovitis. Bioinformatics analysis of potential biomarkers, mRNA–miRNA–lncRNA axes, and signaling pathways in the pathogenesis of RA provides potential targets and theoretical basis for further research on RA.

Methods

The GSE1919 and GSE77298 datasets were downloaded from the Gene Expression Omnibus database (http://www.ncbi.nlm.nih.gov/geo). Perl was used to perform data merging, and R was used to perform batch correction. The “limma” package of R was used to screen differentially expressed genes, and the “clusterProfiler” package was used to perform enrichment analysis of the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes. Search Tool for the Retrieval of Interacting Genes/Proteins was used to construct the protein–protein interaction network, Cytoscape was used for module analysis, and R was used to screen for hub genes. GraphPad Prism was used to plot the receiver operating characteristic curve of the hub genes. Gene set enrichment analysis and competitive endogenous RNA network analysis were performed on hub genes with the greatest diagnostic values. The hub gene with the greatest diagnostic value was verified using immunohistochemical staining.

Results

We obtained nine hub genes (ITGB2, VAMP8, HLA-A, PTAFR, SYK, FCER1G, HLA-DPB1, LCP2, and ACTR2) and four mRNA–miRNA–lncRNA axes (ITGB2-hsa-miR-486-3p-SNHG3, ITGB2-hsa-miR-338-5p-XIST, ITGB2-hsa-miR-5581-3p-XIST, and ITGB2-hsa-miR-1226-5p-XIST) related to the pathogenesis of RA. The nine hub genes were highly expressed, and ITGB2 had the highest diagnostic value for RA. We also identified signaling pathways related to the pathogenesis of RA: Fc epsilon Rl and chemokine signaling pathways. The immunohistochemical results showed that ITGB2 expression was significantly upregulated in RA.

Conclusion

The hub genes, mRNA–miRNA–lncRNA axes, and signaling pathways related to RA pathogenesis identified in this study provide a new research direction for the mechanism, diagnosis, and treatment of RA.

Critical Role of Synovial Tissue-Resident Macrophage and Fibroblast Subsets in the Persistence of Joint Inflammation

Rheumatoid arthritis (RA) is a chronic prototypic immune-mediated inflammatory disease which is characterized by persistent synovial inflammation, leading to progressive joint destruction. Whilst the introduction of targeted biological drugs has led to a step change in the management of RA, 30-40% of patients do not respond adequately to these treatments, regardless of the mechanism of action of the drug used (ceiling of therapeutic response). In addition, many patients who acheive clinical remission, quickly relapse following the withdrawal of treatment. These observations suggest the existence of additional pathways of disease persistence that remain to be identified and targeted therapeutically. A major barrier for the identification of therapeutic targets and successful clinical translation is the limited understanding of the cellular mechanisms that operate within the synovial microenvironment to sustain joint inflammation. Recent insights into the heterogeneity of tissue resident synovial cells, including macropahges and fibroblasts has revealed distinct subsets of these cells that differentially regulate specific aspects of inflammatory joint pathology, paving the way for targeted interventions to specifically modulate the behaviour of these cells. In this review, we will discuss the phenotypic and functional heterogeneity of tissue resident synovial cells and how this cellular diversity contributes to joint inflammation. We discuss how critical interactions between tissue resident cell types regulate the disease state by establishing critical cellular checkpoints within the synovium designed to suppress inflammation and restore joint homeostasis. We propose that failure of these cellular checkpoints leads to the emergence of imprinted pathogenic fibroblast cell states that drive the persistence of joint inflammation. Finally, we discuss therapeutic strategies that could be employed to specifically target pathogenic subsets of fibroblasts in RA.

Mechanism of miR-218-5p in autophagy, apoptosis and oxidative stress in rheumatoid arthritis synovial fibroblasts is mediated by KLF9 and JAK/STAT3 pathways

This study was aimed to investigate the effects of miR-218-5p on the proliferation, apoptosis, autophagy, and oxidative stress of rheumatoid arthritis synovial fibroblasts (RASFs), and the related mechanisms. Quantitative reverse transcription-PCR showed that the expression of miR-218-5p in rheumatoid arthritis synovial tissue was significantly higher than that in healthy synovial tissue. Compared with healthy synovial fibroblasts, miR-218-5p expression was obviously upregulated in RASFs, while KLF9 protein expression was markedly downregulated. Mechanistically, miR-218-5p could directly bind to the 3' untranslated region of KLF9 to inhibit the expression of KLF9. Additionally, transfection of miR-218-5p small interfering RNA (siRNA) inhibited the proliferation but promoted apoptosis and autophagy of RASFs. Simultaneously, miR-218-5p silencing reduced reactive oxygen species and malondialdehyde levels and increased superoxide dismutase and glutathione peroxidase activity to improve oxidative stress in RASFs. More importantly, the introduction of KLF9 siRNA reversed the effects of miR-218-5p siRNA transfection on RASF proliferation, apoptosis, autophagy, and oxidative stress. What is more, silencing miR-218-5p inhibited the activation of JAK2/STAT3 signaling pathway by targeting KLF9. Collectively, knockdown of miR-218-5p could regulate the proliferation, apoptosis, autophagy and oxidative stress of RASFs by increasing the expression of KLF9 and inhibiting the activation of the JAK2/STAT3 signaling pathway, which may provide a potential target for the mechanism research of RA.

Dysregulated microRNA expression in IL-4 transgenic mice, an animal model of atopic dermatitis

IL-4 plays an important role in the pathogenesis of atopic dermatitis (AD). Previously we showed that the expression of genes in chemotaxis, angiogenesis, inflammation and barrier functions is dysregulated in IL-4 transgenic (Tg) mice, a well-characterized AD mouse model. In this study, we aim to study differential expression of microRNAs in IL-4 Tg mice. As compared with wild-type mice, we found that 10 and 79 microRNAs are dysregulated in the skin of IL-4 mice before and after the onset of skin lesions, respectively. Bioinformatic analysis and previous reports show that these dysregulated microRNAs may be involved in the NF-κB, TLRs, IL-4/IL-13, MAPK and other pathways. We also found that miR-139-5p and miR-196b-3p are significantly up-regulated in the peripheral blood of IL-4 Tg mice. Taken together, our data have identified many dysregulated microRNAs in IL-4 Tg mice, which may play important roles in AD pathogenesis and pathophysiology.

Circ_0000396 inhibits rheumatoid arthritis synovial fibroblast growth and inflammatory response via miR-203/HBP1 axis

Background

Circ_0000396 was found to be down-regulated in the rheumatoid arthritis (RA) patients and had a high diagnostic value. However, the function and mechanisms underlying circ_0000396 in RA progression remain unclear.

Methods

The expression of circ_0000396, microRNA (miR)-203 and HMG-box transcription factor 1 (HBP1) was detected using qRT-PCR and western blot. The proliferative and apoptotic capabilities of rheumatoid arthritis synovial fibroblasts (RASFs) were measured by colony formation, CCK-8, flow cytometry and western blot assays, respectively. The levels of interleukins (IL)-6, IL-1β, IL-8 and tumor necrosis factor-α (TNF-α) were detected using enzyme-linked immunosorbent assay (ELISA). The target correlations between miR-203 and circ_0000396 or HBP1 were validated using pull-down and dual-luciferase reporter assay.

Results

Circ_0000396 was decreased in RA synovial tissues and RASFs, and overexpression of circ_0000396 suppressed cell proliferation, induced cell apoptosis and reduced the release of inflammatory cytokine IL-6, IL-1β, IL-8 and TNF-α in RASFs, while circ_0000396 deletion functioned oppositely. MiR-203 was confirmed to be a target of circ_0000396, and miR-203 reversed the protective effects of circ_0000396 on the dysfunction and inflammation of RASFs. HBP1 was a target of miR-203, and silencing miR-203 inhibited RASFs malignant changes by regulating HBP1. In addition, circ_0000396 could regulate HBP1 by sponging miR-203, and HBP1 decrease attenuated the effects of circ_0000396 on RASF growth and inflammation.

Conclusion

Circ_0000396 inhibited the growth and inflammation in RASFs by regulating miR-203/HBP1 axis, providing a potential therapeutic target for RA.

miR-483-3p promotes cell proliferation and suppresses apoptosis in rheumatoid arthritis fibroblast-like synoviocytes by targeting IGF-1

Accumulating evidence suggests that miR-483-3p is implicated in maintaining biological properties in human cancers. However, its biological roles in rheumatoid arthritis (RA) remain unknown. miR-483-3p levels in synovial tissue samples and fibroblast-like synoviocytes (FLSs) were determined using quantitative real-time PCR. The CCK-8 assay and EdU staining were performed to assess cell proliferation in RA FLSs after transfection with miR-483-3p mimics or inhibitor. Flow cytometry with Annexin V-FITC staining or PI staining was performed to assess apoptosis or cell cycle progression in RA FLSs, respectively. miR-483-3p was upregulated in RA, which markedly promoted cell proliferation, induced the G0/G1-to-S phase transition, and suppressed apoptosis in RA FLSs, whereas miR-483-3p silencing yielded opposite results. Moreover, insulin growth factor 1 (IGF-1) was detected as a direct miR-483-3p target. IGF-1 silencing partially restored cell proliferation, the G0/G1-to-S phase transition, and apoptosis suppression in RA FLSs via miR-483-3p inhibition. Our results showed that miR-483-3p promotes RA FLSs proliferation by targeting IGF-1, suggesting a potential strategy for diagnostic and treatment strategy for RA.

Up-regulated microRNA-411 or declined RIPK1 inhibits proliferation and promotes apoptosis of synoviocytes in rheumatoid arthritis mice via decreased NF-κB pathway

Rheumatoid arthritis (RA) is a chronic and inflammatory synovitis systemic disease. Due to the unknown pathogenesis, this study was to investigate the effect of microRNA (miR)-411 on apoptosis and joint function of synoviocytes in RA mice via RIPK1-mediated NF-κB signaling pathway. The collagen-induced arthritis model mice were induced via collagen type II and Freund's adjuvant. The mice were injected with miR-411 mimics, si-RIPK1 or miR-411 mimics + oe-RIPK1 to figure out their roles in cell apoptosis and inflammation of synovial tissues. Synoviocytes were grouped as in animal experiments. Proliferation and apoptosis of synoviocytes were detected upon treatment with overexpressed miR-411 and silenced RIPK1. The expression of miR-411, RIPK1 and NF-κB in synovial tissues and synoviocytes of RA mice was detected by RT-qPCR and Western blot analysis. Poorly expressed miR-411, and highly expressed NF-κB and RIPK1 existed in synovial tissue and synoviocytes of RA. Additionally, it was found that si-RIPK1 decreased NF-κB expression, and miR-411 mimics decreased both RIPK1 and NF-κB. MiR-411 had a targeted relationship with RIPK1. si-RIPK1 or miR-411 mimics promoted cell apoptosis and strained inflammation in synovial tissues of mice with RA. Overexpressed miR-411 or silencing RIPK1 inhibited the proliferation and promoted apoptosis of synoviocytes of RA mice. Up-regulation of miR-411 or down-regulation of RIPK1 had a certain inhibitory effect on RA. This study suggests that up-regulated miR-411 or down-regulated RIPK1 promoted apoptosis and inhibited proliferation of synoviocytes of RA mice, which may be related to the inhibition of NF-κB activation.

lncRNA FAM99A is downregulated in preeclampsia and exerts a regulatory effect on trophoblast cell invasion, migration and apoptosis

Preeclampsia (PE) is a complication of pregnancy, and a leading cause of maternal mortality and morbidity worldwide. Recently, the dysregulation of long non‑coding RNAs (lncRNAs) has been reported to contribute to the pathogenesis and progression of PE. This study aimed to examine the alterations in the lncRNA family with sequence similarity 99 member A (FAM99A) in PE and its effects on trophoblasts. The results of reverse transcription‑quantitative PCR indicated that the expression levels of FAM99A were downregulated in placental tissues from women with severe PE compared with in those from controls. A Transwell invasion assay and wound healing assay revealed that overexpression of FAM99A promoted invasion and migration of HTR‑8/SVneo cells; conversely, knockdown of FAM99A suppressed the invasive and migratory abilities of HTR‑8/SVneo cells. Flow cytometry demonstrated that FAM99A overexpression induced a decrease in the apoptotic rate of cells, whereas knockdown of FAM99A increased the apoptotic rate of HTR‑8/SVneo cells. Western blot analysis revealed that overexpression of FAM99A decreased the protein expression levels of cleaved caspase‑3, cleaved caspase‑9 and Bax, and increased Bcl‑2 protein expression, whereas knockdown of FAM99A had the opposite effects on these protein levels. Overexpression of FAM99A also decreased caspase‑3 activity in HTR‑8/SVneo cells; however, knockdown of FAM99A increased caspase‑3 activity. In addition, overexpression of FAM99A enhanced Wnt/β‑catenin signaling activity, whereas FAM99A knockdown exerted an inhibitory effect on the Wnt/β‑catenin signaling activity in HTR‑8/SVneo cells. In conclusion, these results indicated that FAM99A may serve a role in modulating the functions of trophoblasts, partially via targeting Wnt/β‑catenin signaling.

A selective CB2 agonist protects against the inflammatory response and joint destruction in collagen-induced arthritis mice

Rheumatoid arthritis (RA) is a chronic, inflammatory, synovitis-dominated systemic disease with unknown etiology. RA is characterized by the involvement of multiple affected joints, symmetry, and invasive arthritis of the limbs, which can lead to joint deformity, cartilage destruction, and loss of function. Cannabinoid receptor 2 (CB₂) has potent immunomodulatory and anti-inflammatory effects and is predominantly expressed in non-neuronal tissues. In the current study, the role of CB₂ in the process of inflammatory bone erosion in RA was examined. The selective agonist or high-affinity ligand of CB₂ (4-quinolone-3-carboxamides CB2 agonist, 4Q3C CB₂ agonist, 4Q3C) significantly reduced the severity of arthritis, decreased histopathological findings, and markedly reduced bone erosion in collagen-induced arthritis (CIA) mice. In addition, 4Q3C prevented an increase in the nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio and inhibited the formation of osteoclasts in CIA mice. Furthermore, the expression of tumor necrosis factor-alpha, interleukin-1β, cyclooxygenase-2, and inducible nitric oxide synthase was lower in 4Q3C-treated CIA mice than in control CIA mice. Micro-computed tomography corroborated the finding that 4Q3C reduced joint destruction. These data clearly indicate that the CB₂-selective agonist, 4Q3C, may have anti-inflammatory and anti-osteoclastogenesis effects in RA and may be considered to be a novel treatment for RA.

The MicroRNA-326: Autoimmune diseases, diagnostic biomarker, and therapeutic target

MicroRNAs (miRNAs) are uniquely regulated in healthy, inflamed, activated, cancerous, or other cells and tissues of a pathological state. Many studies confirm that immune dysregulation and autoimmune diseases with inflammation are correlated with various miRNA expression changes in targeted tissues and cells in innate or adaptive immunity. In this review, we will explain the history and classification of epigenetic changes. Next, we will describe the role of miRNAs changes, especially mir-326 in autoimmunity, autoinflammatory, and other pathological conditions. A systematic search of MEDLINE, Embase, and Cochrane Library was presented for all related studies from 1899 to 2017 with restrictions in the English language. In recent years, researchers have concentrated on mostly those roles of miRNA that are correlated with the inflammatory and anti-inflammatory process. Latest studies have proposed a fundamental pathogenic role in cancers and autoinflammatory diseases. Studies have described the role of microRNAs in autoimmunity and autoinflammatory diseases, cancers, and so on. The miRNA-326 expression plays a significant role in autoimmune and other types of diseases.

Novel Immune Mechanisms in Hypertension and Cardiovascular Risk

PURPOSE OF REVIEW

Hypertension is a common disorder with substantial impact on public health due to highly elevated cardiovascular risk. The mechanisms still remain unclear and treatments are not sufficient to reduce risk in majority of patients. Inflammatory mechanisms may provide an important mechanism linking hypertension and cardiovascular risk. We aim to review newly identified immune and inflammatory mechanisms of hypertension with focus on their potential therapeutic impact.

RECENT FINDINGS

In addition to the established role of the vasculature, kidneys and central nervous system in pathogenesis of hypertension, low-grade inflammation contributes to this disorder as indicated by experimental models and GWAS studies pointing to SH2B3 immune gene as top key driver of hypertension. Immune responses in hypertension are greatly driven by neoantigens generated by oxidative stress and modulated by chemokines such as RANTES, IP-10 and microRNAs including miR-21 and miR-155 with other molecules under investigation. Cells of both innate and adoptive immune system infiltrate vasculature and kidneys, affecting their function by releasing pro-inflammatory mediators and reactive oxygen species.

SUMMARY

Immune and inflammatory mechanisms of hypertension provide a link between high blood pressure and increased cardiovascular risk, and reduction of blood pressure without attention to these underlying mechanisms is not sufficient to reduce risk.