OBJECTIVE: To explore the potential causal relationship between intervertebral disc degeneration and certain autoimmune diseases. METHODS: Genome-wide association study (GWAS) data of 5 autoimmune diseases were obtained from large-scale GWAS databases. Data on internal vertebral disc degeneration (IVDD) were derived from the FinnGen consortium, which included 294, 770 controls and 41, 669 cases. A two-sample bidirectional Mendelian randomization (MR) analysis was performed to investigate the potential causal relationship between the 5 autoimmune diseases and IVDD. Multiple analytical methods were adopted, including MR methods such as inverse variance weighting(IVW), MR-Egger, weighted median, weighted mode, and simple mode. Cochran's Q test, leave-one-out analysis, and MR-Egger intercept test were conducted to assess heterogeneity, robustness, and pleiotropy. For the robustness of the results, MR-PRESSO was used to detect outliers, and MR analysis was re-conducted after removing the outliers. RESULTS: The MR analysis results showed that there might be a bidirectional causal relationship between ankylosing spondylitis(AS) and IVDD:AS on IVDD, OR=1.038, 95%CI (1.024, 1.053), P=0.000;and IVDD on AS, OR=2.117, 95%CI(1.065, 4.207), P=0.032. There might be a positive correlation between IVDD and rheumatoid arthritis(RA) as well as systemic lupus erythematosus(SLE):IVDD on RA, OR=1.184, 95%CI(1.071, 1.309), P=0.001;and IVDD on SLE, OR=1.678, 95%CI(1.187, 2.372), P=0.003. There was no significant correlation between ulcerative colitis(UC), autoimmune thyroiditis(ATD) and IVDD. After removing outliers by MR-PRESSO and re-conducting MR analysis, the results did not change qualitatively. Sensitivity analysis indicated that the results were robust to potential sources of bias. CONCLUSION AS and IVDD may be risk factors for each other, and IVDD may be a potential risk factor for RA and SLE. These findings provide a basis for guiding the prevention and combined diagnosis and treatment of IVDD, AS, RA, and SLE, while the specific underlying mechanisms still require further experimental basic research.
Humans ; Intervertebral Disc Degeneration/etiology* ; Mendelian Randomization Analysis ; Autoimmune Diseases/complications* ; Genome-Wide Association Study ; Spondylitis, Ankylosing/genetics* ; Arthritis, Rheumatoid/genetics*

Objective To investigate the effects of hyaluronic acid and proteoglycan-linked protein 1 (HAPLN1) secreted by synovial fibroblasts (FLS) on the polarization of macrophages (Mϕ) in rheumatoid arthritis (RA). Methods Human monocytic leukemia cells (THP-1) were differentiated into Mϕ, which were subsequently exposed to recombinant HAPLN1 (rHAPLN1). RA-FLS were transfected separately with HAPLN1 overexpression plasmid (HAPLN1^OE) or small interfering RNA targeting HAPLN1 (si-HAPLN1), and then co-cultured with Mϕ to establish a co-culture model. The viability of Mϕ was assessed using the CCK-8 assay, and the proportions of pro-inflammatory M1-type and anti-inflammatory M2-type Mϕ were analyzed by flow cytometry. Additionally, the expression levels of inflammatory markers, including interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), and inducible nitric oxide synthase (iNOS), were quantified using quantitative real-time PCR and Western blot analysis. Results The viability of Mϕ was increased in the rHAPLN1 group compared to the control group. Furthermore, both the M1/Mϕ ratio and inflammatory factor levels were elevated in the rHAPLN1 and HAPLN1^OE groups. In contrast, the si-HAPLN1 group exhibited a decrease in the M1/Mϕ ratio and inflammatory factor expression. Notably, the introduction of rHAPLN1 in rescue experiments further promoted Mϕ polarization towards the M1 phenotype. Conclusion HAPLN1, secreted by RA fibroblast-like synoviocytes (RA-FLS), enhances Mϕ polarization towards the M1 phenotype.
Humans ; Arthritis, Rheumatoid/genetics* ; Macrophages/immunology* ; Fibroblasts/metabolism* ; Phenotype ; Extracellular Matrix Proteins/genetics* ; Proteoglycans/genetics* ; Synovial Membrane/cytology* ; Tumor Necrosis Factor-alpha/genetics* ; Interleukin-1beta/genetics* ; Nitric Oxide Synthase Type II/genetics* ; Cell Differentiation ; Coculture Techniques ; THP-1 Cells

The prevalence of rheumatoid arthritis (RA) has sharply increased in recent years, posing a serious threat to human health. RA is characterized as a chronic, multisystem disease with morning stiffness and symmetric small joint pain. However, its fundamental processes are poorly understood. With the advancements in molecular biology techniques, a growing body of research indicates that numerous non-coding RNAs (ncRNAs) are essential for the pathogenesis of RA. These ncRNAs not only contribute to the onset of RA but also play a role in the pathological processes of RA development, including synovial immune inflammation and bone destruction. Chinese medicine (single compounds, single herbs, and compound formulae, as well as non-drug therapies such as acupuncture and moxibustion), offer significant benefits for treating RA. This study examined the role of 3 different ncRNA types (circular RNA, long ncRNA, and microRNA) as biomarkers in RA diagnosis, as well as their regulatory roles in rheumatoid arthritis fibroblast-like synoviocytes functions such as inflammatory response, proliferation, cell cycle, apoptosis, and invasion. Additionally, the study explored the mechanisms by which Chinese medicine regulates these ncRNAs, with the goal of offering innovative strategies for RA treatment.
Arthritis, Rheumatoid/pathology* ; Humans ; RNA, Untranslated/metabolism* ; Medicine, Chinese Traditional ; Synoviocytes/metabolism* ; RNA, Circular ; Biomarkers/metabolism* ; Apoptosis/genetics*

OBJECTIVES: To investigate the regulatory effect of LINC00837/miR-671-5p/SERPINE2 functional axis on pathological processes of fibroblast-like synovial cells (FLS) in rheumatoid arthritis (RA). METHODS: RA-FLS were transfected with a LINC00837 overexpression plasmid (pcDNA3.1-LINC00837), a LINC00837 interference plasmid (siRNA-LINC00837), or their respective negative control plasmids (pcDNA3.1-NC and siRNA-NC). Dual luciferase was used to verify the targeting relationship between LINC00837 and miR-671-5p and between miR-671-5p and SERPINE2. RT-qPCR was used to detect the expression levels of LINC00837, miR-671-5p and SERPINE2 in normal FLS or the transfected cells, whose proliferation and migration abilities were assessed using Edu assay and scratch healing assay and by detecting the expression levels of Ki-67, PCNA, E-cadherin and N-cadherin with Western blotting. The changes in cellular secretion of the inflammatory cytokines (TNF‑α, IL-17, IL-4 and IL-10) were examined using ELISA. RESULTS: Dual luciferase reporter gene assay showed that LINC00837 was capable of binding to the 3'-UTR of miR-671-5p, and the latter bound to the 3-UTR of SERPINE2 at specific binding sites between them. Compared with normal FLS, RA-FLS showed significantly increased expressions of LINC00837 and SERPINE2, lowered miR-671-5p expression and enhanced proliferation and migration abilities with increased expressions of pro-inflammatory cytokines and reduced expressions of anti-inflammatory cytokines. Transfection of RA-FLS with pcDNA-LINC00837 further enhanced cell proliferation and migration and the changes in the inflammatory cytokines, while transfection with si-LINC00837 produced the opposite changes. CONCLUSIONS RA-FLS have a LINC00837/miR-671-5p/SERPINE2 functional axis, which regulates cell proliferation, migration and secretion of inflammatory factors, and interventions targeting LINC00837 may provide a potential strategy to regulate the pathological processes in RA-FLS.
Arthritis, Rheumatoid/metabolism* ; MicroRNAs/metabolism* ; Humans ; Cell Proliferation ; Cell Movement ; Synovial Membrane/pathology* ; RNA, Long Noncoding/genetics* ; Fibroblasts/metabolism* ; Synoviocytes/metabolism* ; Cells, Cultured ; Transfection

OBJECTIVES: To explore the role of oxidative stress and immune infiltration in rheumatoid arthritis (RA). METHODS: RA datasets GSE55235 (10 RA vs 10 normal samples) and GSE55457 (13 RA vs 10 normal samples) from the GEO database were merged as the test set to identify the differentially expressed genes (DEGs) in RA using R. The DEGs were intersected with oxidative stress-related genes to obtain oxidative stress-associated DEGs. KEGG and GO enrichment analyses of the DEGs were performed, and the RA-related pathways and biological processes were analyzed using GSEA. A protein-protein interaction (PPI) network was constructed using STRING and Cytoscape, and the top 10 key genes were obtained using the Degree algorithm. The validation dataset GSE1919 from GEO database was used for ROC analysis of the key genes to obtain the core genes, and their correlations with infiltrating immune cells were analyzed using CIBERSORT. The results were verified by RT-qPCR for detecting expression levels of the core genes in RA and normal joint samples. RESULTS: We identified 89 oxidative stress-associated DEGs. Enrichment analysis suggested that these DEGs were involved in the biological processes including oxidative stress, chemical stress response, reactive oxygen species response, and lipopolysaccharide response. ROC analysis showed that the 5 core genes (STAT1, MMP9, MYC, CCL5, and JUN) all had AUC values >0.7, indicating their high diagnostic sensitivity and specificity for RA. These genes were closely correlated with immune cells, particularly T cells. RT-qPCR confirmed significant differential expressions of the core genes between RA and normal samples. CONCLUSIONS Oxidative stress and diverse immune responses are features of RA, and the immune responses contribute to activation of oxidative stress. The identified core genes can potential serve as new diagnostic markers for RA.
Arthritis, Rheumatoid/genetics* ; Oxidative Stress/genetics* ; Humans ; Computational Biology ; Protein Interaction Maps ; Gene Expression Profiling ; Gene Regulatory Networks

OBJECTIVES: To investigate the causal associations between autoimmune diseases and aplastic anemia (AA) using Mendelian randomization analysis. METHODS: Publicly available genome-wide association study (GWAS) data were utilized to obtain single nucleotide polymorphisms (SNPs) associated with autoimmune diseases and AA for analysis. The inverse variance weighted (IVW) method was employed as the primary analytical approach, with MR Egger, Weighted Mode, Weighted Median, and Simple Mode methods serving as complementary analyses. Heterogeneity and pleiotropy analyses were conducted using designated functions, and the robustness of Mendelian randomization results was assessed using leave-one-out analysis. RESULTS: The two-sample Mendelian randomization analysis using the IVW method revealed significant positive causal associations of rheumatoid arthritis (OR=1.094, 95% CI: 1.023-1.170, P=0.009, adjusted P=0.042), systemic lupus erythematosus (OR=1.111, 95% CI: 1.021-1.208, P=0.015, adjusted P=0.036), Hashimoto thyroiditis (OR=1.206, 95% CI: 1.049-1.387, P=0.009, adjusted P=0.029), and Sicca syndrome (OR=1.173, 95% CI: 1.054-1.306, P=0.004, adjusted P=0.035) with AA, which was supported by the results from the Weighted Median method. Sensitivity analyses indicated no evidence of pleiotropy or heterogeneity, and leave-one-out analysis confirmed the robustness of the causal relationships. No direct evidence was found linking Graves' disease, ulcerative colitis, Crohn's disease, autoimmune hepatitis, primary biliary cholangitis, or primary sclerosing cholangitis with AA (P>0.05, adjusted P>0.05), indicating a lack of causal association. Reverse Mendelian randomization results and multiple corrections indicated that AA was not an influencing factor for autoimmune diseases (adjusted P>0.05). CONCLUSIONS Our findings support at the genetic level that rheumatoid arthritis, systemic lupus erythematosus, Hashimoto thyroiditis, and Sicca syndrome are risk factors for AA, and confirm a causal association of the these 4 autoimmune diseases with an increased risk of AA.
Humans ; Mendelian Randomization Analysis ; Anemia, Aplastic/genetics* ; Autoimmune Diseases/complications* ; Polymorphism, Single Nucleotide ; Genome-Wide Association Study ; Arthritis, Rheumatoid/genetics* ; Lupus Erythematosus, Systemic/genetics* ; Genetic Predisposition to Disease

Andrographolide sulfonate (AS) is a sulfonated derivative of andrographolide extracted from Andrographis paniculata (Burm.f.) Nees, and has been approved for several decades in China. The present study aimed to investigate the novel therapeutic application and possible mechanisms of AS in the treatment of rheumatoid arthritis. Results indicated that administration of AS by injection or gavage significantly reduced the paw swelling, improved body weights, and attenuated pathological changes in joints of rats with adjuvant-induced arthritis. Additionally, the levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and IL-1β in the serum and ankle joints were reduced. Bioinformatics analysis, along with the spleen index and measurements of IL-17 and IL-10 levels, suggested a potential relationship between AS and Th17 cells under arthritic conditions. In vitro, AS was shown to block Th17 cell differentiation, as evidenced by the reduced percentages of CD4⁺ IL-17A⁺ T cells and decreased expression levels of RORγt, IL-17A, IL-17F, IL-21, and IL-22, without affecting the cell viability and apoptosis. This effect was attributed to the limited glycolysis, as indicated by metabolomics analysis, reduced glucose uptake, and pH measurements. Further investigation revealed that AS might bind to hexokinase2 (HK2) to down-regulate the protein levels of HK2 but not glyceraldehyde-3-phosphate dehydrogenase (GAPDH) or pyruvate kinase M2 (PKM2), and overexpression of HK2 reversed the inhibition of AS on Th17 cell differentiation. Furthermore, AS impaired the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signals in vivo and in vitro, which was abolished by the addition of lactate. In conclusion, AS significantly improved adjuvant-induced arthritis (AIA) in rats by inhibiting glycolysis-mediated activation of PI3K/AKT to restrain Th17 cell differentiation.
Animals ; Th17 Cells/immunology* ; Diterpenes/pharmacology* ; Arthritis, Rheumatoid/metabolism* ; Proto-Oncogene Proteins c-akt/immunology* ; Glycolysis/drug effects* ; Cell Differentiation/drug effects* ; Phosphatidylinositol 3-Kinases/genetics* ; Rats ; Male ; Rats, Sprague-Dawley ; Humans ; Andrographis paniculata/chemistry* ; Arthritis, Experimental/drug therapy* ; Interleukin-17/immunology* ; Signal Transduction/drug effects*

Shaoyao Gancao Decoction(SGD) is a classic formula used in the clinical treatment of joint diseases, such as rheumatoid arthritis(RA), though its mechanism of action remains unclear. This study aimed to explore the mechanism of SGD in treating RA through chemical and network pharmacology analyses, combined with cellular experiments. UPLC-Orbitrap-MS~2 was used to qualitatively analyze SGD and drug-containing serum of rats after oral administration of SGD, thereby identifying the chemical composition and plasma components of SGD. Potential targets for the plasma components in treating RA were identified using the SwissTargetPrediction, PharmMapper, GeneCards, and DrugBank databases, and a protein-protein interaction(PPI) network was constructed using the STRING data platform. GO functional enrichment and KEGG pathway enrichment analyses were conducted using the Metascape database. Molecular docking and lipopolysaccharide(LPS)-induced RAW264.7 cell experiments were utilized for in vitro validation. The results identified 95 compounds in SGD, including 15 prototypical absorbed components, i.e., 7 flavonoids, 5 terpenoids, 2 phenolic compounds, and 1 other compound. Network pharmacology analysis revealed that licoisoflavanone, liquiritin apioside, 5-hydroxyferulic acid, albiflorin, hederagenin, and paeoniflorin were the pharmacodynamic components of SGD for treating RA. The core targets of SGD for RA treatment were identified as SRC, MAPK, EGFR, HSP90AA1, and STAT3, with regulation of the NF-κB, PI3K-Akt, and MAPK signaling pathways identified as key mechanisms for anti-RA effects of SGD. Molecular docking results showed that the six core components exhibited high affinity with the key targets SRC, MAPK, and NF-κB. In vitro cellular experiments demonstrated that SGD down-regulated the expression of inflammatory factors, including interleukin-1β(IL-1β), cyclooxygenase-2(COX-2), and tumor necrosis factor-α(TNF-α), in LPS-induced RAW264.7 cells. Western blot analysis revealed that SGD significantly reduced the phosphorylation levels of NF-κB p65 and p38 MAPK proteins. This study provides a scientific basis for further research into the active components and mechanisms of action of SGD in treating RA.
Animals ; Drugs, Chinese Herbal/chemistry* ; Arthritis, Rheumatoid/metabolism* ; Mice ; Network Pharmacology ; RAW 264.7 Cells ; Rats ; Chromatography, High Pressure Liquid/methods* ; Molecular Docking Simulation ; Male ; Rats, Sprague-Dawley ; Humans ; Signal Transduction/drug effects* ; NF-kappa B/genetics* ; Protein Interaction Maps/drug effects*

This study aimed to investigate the potential role of Colquhounia Root Tablets against bone destruction in rheumatoid arthritis(RA) and its molecular mechanism. The study used ultra-performance liquid chromatography-mass spectrometry to analyze the major components of Colquhounia Root Tablets and predicted its candidate target gene set based on the major components. The key targets of RA bone destruction were obtained through GeneCards and the Database of Genetics and Medical Literature(OMIM), protein-protein interaction(PPI) network was constructed, and the key targets were identified by topological analysis. The molecular mechanism of Colquhounia Root Tablets against RA bone destruction was further revealed using Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) enrichment analysis. The effects of Colquhounia Root Tablets on macrophage viability was assessed by MTS assay and screened for non-toxic concentrations. A model of receptor activator of nuclear factor-κB(RANKL) induced osteoclast differentiation in vitro was constructed. Colquhounia Root Tablets were used to observe the formation and differentiation of osteoclasts by tartrate-resistant acid phosphatase(TRAP) staining and fibrous actin(F-actin) staining, and the effects of Colquhounia Root Tablets on the changes of core target proteins in the osteoclast differentiation system were detected by immunofluorescence and Western blot. The results showed that the main components of Colquhounia Root Tablets included 14 compounds such as triptolide, celastrol, and triptophenolide. Further network analysis revealed that heat-shock protein 90(HSP90) was the key target gene of Colquhounia Root Tablets for anti-RA bone destruction. TRAP staining and F-actin staining showed that the number and area of TRAP-positive polymorphonuclear cells, as well as actin rings, were reduced in a dose-dependent manner after the intervention of Colquhounia Root Tablets(P<0.01). Western blot results showed that the expression of HSP90 protein was significantly reduced after intervention with Colquhounia Root Tablets at 20 and 40 μg·mL~(-1)(P<0.01); Colquhounia Root Tablets at 10 μg·mL~(-1) could significantly decrease the expression of necrosis factor receptor associated molecule 6(TRAF6) and nuclear factor of activated T cells 1(NFATc1) proteins(P<0.01); moreover, all doses of Colquhounia Root Tablets significantly reduced the expression of osteoclast differentiation marker proteins matrix metalloproteinase 9(MMP9) and cathepsin K(CTSK)(P<0.01).Immunofluorescence results further confirmed that Colquhounia Root Tablets significantly inhibited HSP90 and CTSK levels, as well as NFATc1 activation in osteoblasts. In conclusion, the present study confirmed that Colquhounia Root Tablets may inhibit RANKL-induced osteoclast differentiation by regulating the key target of HSP90, thus exerting an anti-RA bone destruction effect, which will provide a new idea for Colquhounia Root Tablets to prevent and treat bone destruction in rheumatoid arthritis.
Osteoclasts/metabolism* ; Mice ; Animals ; Cell Differentiation/drug effects* ; HSP90 Heat-Shock Proteins/genetics* ; Drugs, Chinese Herbal/chemistry* ; Plant Roots/chemistry* ; Humans ; Arthritis, Rheumatoid/physiopathology* ; Protein Interaction Maps/drug effects*

Objective To investigate the effect of SMAD family member 3(SMAD3) silenced by small interfering RNA (siRNA) on macrophage polarization and transforming growth factor β1 (TGF-β1)/ SMAD family signaling pathway in rheumatoid arthritis (RA). Methods RA macrophages co-cultured with rheumatoid arthritis fibroblast-like synoviocytes (RA-FLS) were used as a cell model. TGF-β1 was used to stimulate macrophages, and SMAD3-specific siRNA (si-SMAD3) and negative control siRNA (si-NC) were transfected into human RA macrophages co-cultured in Transwell^TM chamber. The expression of SMAD3 mRNA was detected by real-time fluorescence quantitative PCR, and the expression of TGF-β1, SMAD3 and SMAD7 protein was detected by Western blot analysis. The contents of TGF-β1 and IL-23 in cell culture supernatant were determined by ELISA. Cell proliferation was detected by CCK-8 assay. Transwell^TM chamber was used to measure cell migration. Results Compared with the model group and the si-NC group, the expression of TGF-β1, SMAD3 mRNA and protein in RA macrophages decreased significantly after silencing SMAD3. In addition, the secretion of IL-23 decreased significantly, and the cell proliferation activity and cell migration were inhibited, with high expression of SMAD7. Conclusion Knockdown of SMAD3 can promote M2 polarization and SMAD7 expression in RA macrophages.
Humans ; Arthritis, Rheumatoid/genetics* ; Interleukin-23 ; Macrophages ; RNA, Messenger ; RNA, Small Interfering/genetics* ; Smad7 Protein/genetics* ; Transforming Growth Factor beta1/genetics* ; Smad3 Protein/genetics* ; Gene Silencing