The effects of miR-26b-5p on fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS) via targeting EZH2

Irisin mitigates rheumatoid arthritis by suppressing mitochondrial fission via inhibiting YAP-Drp1 signaling pathway

BACKGROUND

Irisin is a hormone-like factor secreted by muscle cells and produced by cleavage of the membrane protein fibronectin type III domain protein 5 (FNDC5), which exerts anti-inflammatory and anti-proliferative effects. However, the effects and the underlying mechanisms of irisin in rheumatoid arthritis (RA) are still unclear.

METHOD

Collagen-induced arthritis (CIA) model was induced in DBA/1 mice and then treated with irisin. Arthritis index, paw thickness, weight, number of affected paws, serum inflammatory factors and related pathological tests were measured. RA fibroblast-like synoviocytes (RA-FLSs) were pretreated with IL-1β and irisin, and the migration, proliferation, invasion, oxidative stress and mitochondrial related function of RA-FLSs were detected.

RESULTS

Irisin significantly improved arthritis symptoms in CIA mice, as indicated by reduced arthritis index, alleviated paw thickness, decreased the number of affected paws and inhibited release of inflammatory factors. Irisin alleviated joint destruction, FLSs proliferation and the expression of YES-associated protein (YAP) and mitochondrial dynamic related protein 1 (Drp1) in the FLSs of CIA mice. In vitro experiment, irisin inhibited the proliferation, migration and invasion of RA-FLSs and improved oxidative stress induced by IL-1β, thereby restraining the pathogenic transformation of RA-FLSs. Mechanically, irisin suppressed the nuclear translocation of YAP, in turn, could reduce the synthesis of Drp1 protein and inhibit the mitochondrial fission of RA-FLSs, which was reversed by YAP agonists. Therefore, irisin has a protective effect on RA.

CONCLUSION

Irisin inhibits the proliferation, migration, invasion and inflammatory response of RA-FLSs by inhibiting the YAP-Drp1 signaling pathway, which implies a potential therapeutic effect on RA.

Panlongqi tablet suppresses adjuvant-induced rheumatoid arthritis by inhibiting the inflammatory reponse in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Panlongqi Tablet is prepared with the ancestral secret recipe provided by Mr. Wang Jiacheng, a famous specialist in orthopedics and traumatology of China. The efficacy and safety of PLQT have been supported by years of clinical practice in the treatment of joint-related conditions. Has remarkable effect for treating rheumatoid arthritis (RA) clinically. However, its mechanism is not entirely clear.

AIM OF THE STUDY

We aim to evaluate the anti-inflammatory activity of PLQT and explore its mechanism in adjuvant-induced arthritis (AA) mice and LPS-induced Human fibroblast-like synovial (HFLS) cells.

MATERIALS AND METHODS

To this end, we analyzed the active ingredients in PLQT by HPLC-MS/MS. Furthermore, the anti-RA effect of PLQT was studied through proliferation, apoptosis, foot swelling, cytokine levels, immune organ index, histopathology and related signal pathways in LPS-induced HFLS cells and AA-treated mice.

RESULTS

HPLC-MS/MS results showed that PLQT contained a variety of active compounds, such as epicatechin, imperatorin, hydroxysafflor yellow A and so on. PLQT significantly inhibited the abnormal proliferation of HFLS cells induced by LPS, promoted cell apoptosis. In AA-treated mice, PLQT alleviated RA symptoms by alleviating paw swelling, synovial hyperplasia, pannus formation, inflammatory cell infiltration, and inhibiting abnormal immune responses. The results showed that PLQT significantly decreased the expression of inflammatory mediators (IL-1β, IL-6, IL-17) in vivo and in vitro, which may be related to the regulation of PI3K/Akt, MAPK and JAK/STAT signaling pathways.

CONCLUSION

Based on serum pharmacology and in vivo pharmacology studies, PLQT may regulate RA symptoms by regulating inflammatory and immune response-related pathways, which is an effective method for the treatment of RA.

MiR-216a-3p inhibits the proliferation and invasion of fibroblast-like synoviocytes by targeting dual-specificity phosphatase 5

Dual-specificity phosphatase 5 (DUSP5) is a novel anti-inflammatory modulator in many inflammatory diseases. However, the role of DUSP5 in fibroblast-like synoviocytes (FLS) of rheumatoid arthritis (RA) remains unknown. In this study, we aimed to explore the biological function and regulation of DUSP5 in FLS. We found that lower DUSP5 expression level was detected in collagen-induced arthritis (CIA) and synoviocyte MH7A. Overexpression of DUSP5 markedly decreased the proliferation, migration, and invasion of MH7A, which correlated with suppressing the phosphorylation of extracellular signal-regulated kinase (ERK). Moreover, DUSP5 was identified as a novel target gene of miR-216a-3p, which was upregulated in FLS. Therefore, DUSP5 expression was negatively regulated by miR-216a-3p, and the effect of DUSP5 overexpression on FLS was reversed by miR-216a-3p mimics. Overall, our study demonstrates that DUSP5 is a miR-216a-3p target gene and its anti-inflammatory function in FLS via inactivation of ERK. These results revealed that the miR-216a-3p/DUSP5 pathway may play a crucial role in the malignant behavior of FLS, which may serve as a new target for the treatment of RA.

Evaluation of altered miRNA expression pattern to predict COVID-19 severity

Outbreak of COVID-19 pandemic in December 2019 affected millions of people globally. After substantial research, several biomarkers for COVID-19 have been validated however no specific and reliable biomarker for the prognosis of patients with COVID-19 infection exists. Present study was designed to identify specific biomarkers to predict COVID-19 severity and tool for formulating treatment. A small cohort of subjects (n = 43) were enrolled and categorized in four study groups; Dead (n = 16), Severe (n = 10) and Moderate (n = 7) patients and healthy controls (n = 10). Small RNA sequencing was done on Illumina platform after isolation of microRNA from peripheral blood. Differential expression (DE) of miRNA (patients groups compared to control) revealed 118 down-regulated and 103 up-regulated known miRNAs with fold change (FC) expression ≥2 folds and p ≤ 0.05. DE miRNAs were then subjected to functional enrichment and network analysis. Bioinformatic analysis resulted in 31 miRNAs (24 Down-regulated; 7 up-regulated) significantly associated with COVID-19 having AUC>0.8 obtained from ROC curve. Seventeen out of 31 DE miRNAs have been linked to COVID-19 in previous studies. Three miRNAs, hsa-miR-147b-5p and hsa-miR-107 (down-regulated) and hsa-miR-1299 (up-regulated) showed significant unique DE in Dead patients. Another set of 4 miRNAs, hsa-miR-224-5p (down-regulated) and hsa-miR-4659b-3p, hsa-miR-495-3p and hsa-miR-335-3p were differentially up-regulated uniquely in Severe patients. Members of three miRNA families, hsa-miR-20, hsa-miR-32 and hsa-miR-548 were significantly down-regulated in all patients group in comparison to healthy controls. Thus a distinct miRNA expression profile was observed in Dead, Severe and Moderate COVID-19 patients. Present study suggests a panel of miRNAs which identified in COVID-19 patients and could be utilized as potential diagnostic biomarkers for predicting COVID-19 severity.

Trends and frontiers in natural products for arthritis, 2000-2021: A bibliometric analysis

BACKGROUND

Arthritis has become one of the trouble diseases that upsets people. A growing number of studies have shown that natural products have great potential for the treatment of arthritis. However, few bibliometrics have been systematically studied in this area. This paper analyzes the literature data of natural products on the arthritis research, and the research hot spots and future research directions of the treatment of arthritis by natural products were explored.

METHOD

Through CiteSpace, VOSviewer software and Bibliometricx under the R language environment, the article and review literatures on the treatment of arthritis with natural drugs in the Web of Science core collection database were analyzed by bibliometric analysis.

RESULTS

On December 28, 2021, a total of 2102 records were retrieved, 81.69% publications were issued in 2012 to 2021, mainly in China-dominated Asian countries, with cooperation among countries. The analysis of the number of articles published by institutions shows that the number of articles published by China Academy of Chinese Medical Sciences is up to 82. Lu, Aiping and Smolen, JS are the authors with the highest citation frequency and co-citation frequency. Keywords analysis showed that the research of natural drugs mainly focused on gene expression, anti-inflammatory and other mechanisms and signaling pathways. With the progress of science and technology and the integration of multi-disciplines, the research on natural drugs for arthritis will be more in-depth and specific.

CONCLUSION

In this study, literature metrology analysis was conducted on natural products in the treatment of arthritis, in order to grasp the background, trends and frontiers of the research, and predict possible research hotspots in the future. It is expected to provide some reference value and direction for future scholars in this field.

Emerging role of EZH2 in rheumatic diseases: A comprehensive review

Enhancer of zeste homolog 2 (EZH2) is a histone methylated enzyme. It trimethylates histone 3 lysine 27 (H3K27) to regulate epigenetic processes. Recently, studies showed excessive expression of EZH2 in rheumatic diseases, such as systemic lupus erythematosus, rheumatoid arthritis, osteoarthritis, and systemic sclerosis. Moreover, epigenetic modification of EZH2 regulates differentiation and proliferation of different immune cells. Therefore, in this review, we comprehensively discuss the role of EZH2 in rheumatic diseases. Collection of the evidence may provide a basis for further understanding the role of EZH2 and give potential for targeting these diseases.

EZH2 regulates the balance between osteoclast and osteoblast differentiation to inhibit arthritis-induced bone destruction

Enhancer of zeste homolog 2 (EZH2) has been noted to contribute to the pathogenesis of autoimmune diseases. This study sought to investigate the mechanism of EZH2 in osteoclast (OCL) and osteoblast (OBL) differentiation (OCLD/OBLD) and bone destruction in RA. The animal model of collagen-induced arthritis (CIA) was established, followed by arthritis index (AI) scoring and histological staining, and measurements of inflammatory cytokines levels. The number of OCLs was detected via Tartrate-resistant acid phosphatase (TRAP) staining, and levels of OBL markers were determined by Western blot analysis. Trimethylated histone H3 at lysine 27 (H3K27me3) expression and its enrichment in the Ndrg2 promoter were detected. Collaborative experiments were performed with GSK-J1 or sh-Ndrg2 in CIA mice with EZH2 knockdown. EZH2 was upregulated while Ndrg2 was downregulated in knee joint tissues of CIA mice. Silencing EZH2 reduced AI scores, pathological injury of the knee joint, levels of inflammatory cytokines, and TRAP-positive cells, and increased protein levels of RUNX2 and BMP2. EZH2 promoted H3K27me3 level in the Ndrg2 promoter to inhibit Ndrg2 transcription. H3K27me3 upregulation or Ndrg2 downregulation reversed the role of silencing EZH2 in bone destruction. Overall, EZH2 repressed OBLD and promoted OCLD to aggravate bone destruction in CIA mice through H3K27me3/Ndrg2.

Immunomodulatory Properties of Human Breast Milk: MicroRNA Contents and Potential Epigenetic Effects

Infants who are exclusively breastfed in the first six months of age receive adequate nutrients, achieving optimal immune protection and growth. In addition to the known nutritional components of human breast milk (HBM), i.e., water, carbohydrates, fats and proteins, it is also a rich source of microRNAs, which impact epigenetic mechanisms. This comprehensive work presents an up-to-date overview of the immunomodulatory constituents of HBM, highlighting its content of circulating microRNAs. The epigenetic effects of HBM are discussed, especially those regulated by miRNAs. HBM contains more than 1400 microRNAs. The majority of these microRNAs originate from the lactating gland and are based on the remodeling of cells in the gland during breastfeeding. These miRNAs can affect epigenetic patterns by several mechanisms, including DNA methylation, histone modifications and RNA regulation, which could ultimately result in alterations in gene expressions. Therefore, the unique microRNA profile of HBM, including exosomal microRNAs, is implicated in the regulation of the genes responsible for a variety of immunological and physiological functions, such as FTO, INS, IGF1, NRF2, GLUT1 and FOXP3 genes. Hence, studying the HBM miRNA composition is important for improving the nutritional approaches for pregnancy and infant's early life and preventing diseases that could occur in the future. Interestingly, the composition of miRNAs in HBM is affected by multiple factors, including diet, environmental and genetic factors.

Histone methyltransferase EZH2 in proliferation, invasion, and migration of fibroblast-like synoviocytes in rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA) may lead to irreversible joint damage. The role of histone modifications in RA has been emphasized. This study investigated the effect of histone methyltransferase EZH2 on fibroblast-like synoviocytes (FLSs) in RA.

MATERIALS AND METHODS

Synovial tissues were collected from RA patients and non-RA patients (NC). RA-FLSs and NC-FLSs were isolated and identified using flow cytometry. EZH2 expression in synovial tissues and FLSs was detected using RT-qPCR and Western blot. The proliferation, migration, and invasion of RA-FLSs and NC-FLSs were measured using MTT, EdU, and Transwell assays. The binding of EZH2, H3K27me3, and miR-22-3p was analyzed using ChIP assay. The targeting relationship between miR-22-3p and CYR61 was verified using dual-luciferase assay. miR-22-3p and CYR61 expressions were detected using RT-qPCR. CYR61 and H3K27me3 levels were detected using Western blot. Functional rescue experiments were performed to verify the effect of miR-22-3p or CYR61 on RA-FLSs.

RESULTS

EZH2 was highly expressed in synovial tissues and FLSs from RA patients. The proliferation, migration, and invasion ability of RA-FLSs was stronger than that of NC-FLSs. Downregulation of EZH2 repressed proliferation, migration, and invasion of RA-FLSs. EZH2 inhibited miR-22-3p expression by binding to the miR-22-3p promoter and increasing H3K27me3 methylation level, and thereby upregulated CYR61 expression. Downregulation of miR-22-3p or overexpression of CYR61 annulled the inhibitory effect of EZH2 silencing on RA-FLS proliferation, migration, and invasion.

CONCLUSION

EZH2 bound to the miR-22-3p promoter and inhibited miR-22-3p expression by upregulating H3K27me3 level, thereby promoting CYR61 expression and inducing the proliferation, migration, and invasion of RA-FLSs.