Over-expression of extracellular superoxide dismutase in mouse synovial tissue attenuates the inflammatory arthritis

Oxidative stress such as reactive oxygen species (ROS) within the inflamed joint have been indicated as being involved as inflammatory mediators in the induction of arthritis. Correlations between extracellular- superoxide dismutase (EC-SOD) and inflammatory arthritis have been shown in several animal models of RA. However, there is a question whether the over-expression of EC-SOD on arthritic joint also could suppress the progression of disease or not. In the present study, the effect on the synovial tissue of experimental arthritis was investigated using EC-SOD over-expressing transgenic mice. The over-expression of EC- SOD in joint tissue was confirmed by RT-PCR and immunohistochemistry. The degree of the inflammation in EC-SOD transgenic mice was suppressed in the collagen-induced arthritis model. In a cytokine assay, the production of pro-inflammatory cytokines such as, IL-1β, TNFα, and matrix metalloproteinases (MMPs) was decreased in fibroblast-like synoviocyte (FLS) but not in peripheral blood. Histological examination also showed repressed cartilage destruction and bone in EC-SOD transgenic mice. In conclusion, these data suggest that the over-expression of EC-SOD in FLS contributes to the activation of FLS and protection from joint destruction by depressing the production of the pro-inflammatory cytokines and MMPs. These results provide EC-SOD transgenic mice with a useful animal model for inflammatory arthritis research.     

IL-17-deficient allogeneic bone marrow transplantation prevents the induction of collagen-induced arthritis in DBA/1J mice

IL-17-producing CD4⁺ T cells (Th17) play important functions in autoimmune diseases and allograft rejection of solid organs. We examined the effects of IL 17 and its mechanism of action on arthritis in a murine collagen-induced arthritis (CIA) model using bone marrow transplantation (BMT) system. DBA/1J mice were administered a lethal radiation dose and then rescued with bone marrow derived from either wild-type (WT) or IL-17^-/- mice on C57BL/6 background mice. CIA was induced after the bone marrow transplant, and disease progression was characterized. DBA/1J mice with CIA that received IL-17^-/- donor bone marrow showed potently inhibited development and severity of clinical arthritis as compared with CIA mice that received WT bone marrow. Reduced secretion of the pro-inflammatory cytokines tumor necrosis factor-α, IL-1β, and IL-6, and collagen-specific T cell responses were observed in mice that received IL-17^-/- bone marrow. IL-17 blockade also inhibited effector T cell proliferation by reciprocally regulating the Treg/Th17 ratio. IL-17 blockade prevented joint destruction in mice with CIA. These findings suggest that CIA with BMT is a viable method of immunological manipulation and that IL-17 deficiency suppresses severe joint destruction and inflammation in CIA mice. There may be clinical benefits in blocking IL-17 and BMT in the treatment of rheumatoid arthritis.     

Novel calorimetric properties of human cartilage samples in rheumatoid arthritis

During recent years, knowledge of rheumatoid arthritis has increased, and management of the disease has improved. A limited number of papers have been published before on the subject of thermal analysis of degenerative cartilage but rheumatoid arthritis (RA) has not been studied previously. A new protocol had to be established before the investigation. The purpose of this study was to further characterize the altered metabolism in human RA cartilage that promotes disease progression. Previously, these methods have not been used for this purpose. The use of thermal analysis could be an effective method for controlling the relationship between biomarkers and disease progression.     

一锅法合成16－咪唑甲基甾酮

去氢表雄酮或３－甲氧基雌酮与聚甲醛、咪唑一锅反应，直接而简便地合成了１６－咪唑甲基或１６－羟甲基－１６－咪唑甲基甾酮。     

Synergy between adiponectin and interleukin-1β on the expression of interleukin-6, interleukin-8, and cyclooxygenase-2 in fibroblast-like synoviocytes

To determine whether adiponectin may have synergistic effects in combination with the proinflammatory cytokine interleukin (IL)-1β regarding the production of proinflammatory mediators during arthritic joint inflammation, synovial cells from rheumatoid arthritis (RA) patients were treated with adiponectin, IL-1β, and their combination for 24 h. Culture supernatant was collected and analyzed by enzyme-linked immunosorbent assay for levels of IL-6, IL-8, prostaglandin E(2) (PGE(2)), vascular endothelial growth factor (VEGF), and matrix metalloproteinases (MMPs). Adiponectin-mediated intracellular signaling pathways were investigated to elucidate the molecular mechanisms underlying their synergy. The association of proinflammatory mediators with adiponectin was investigated in the synovial fluid of arthritis patients. Adiponectin functioned synergistically with IL-1β to activate IL-6, IL-8, and PGE2 expression in RA fibroblast-like synoviocytes; Levels of VEGF, MMP-1, and MMP-13 were not synergistically stimulated. Adiponectin and IL-1β each increased the expression of both adiponectin receptor 1 and IL-1 receptor 1. However, adiponectin and IL-1β did not synergistically support the degradation of IκB-α or the nuclear translocation of NF-κB. Synergistically increased gene expression was significantly inhibited by MG132, an NF-κB inhibitor. Supporting the in vitro results, IL-6 and IL-8 levels were positively associated with adiponectin in synovial joint fluid from patients with RA, but not osteoarthritis (OA). In conclusion, adiponectin and IL-1β may synergistically stimulate the production of proinflammatory mediators through unknown signaling pathways during arthritic joint inflammation. Adiponectin may be more important to the pathogenesis of RA than previously thought.     

Glucocorticoid-loaded core-cross-linked polymeric micelles with tailorable release kinetics for targeted therapy of rheumatoid arthritis

Polymerizable and hydrolytically cleavable dexamethasone (DEX, red dot in picture) derivatives were covalently entrapped in core-cross-linked polymeric micelles that were prepared from a thermosensitive block copolymer (yellow and gray building block). By varying the oxidation degree of the thioether in the drug linker, the release rate of DEX could be controlled. The DEX-loaded micelles were used for efficient treatment of inflammatory arthritis in two animal models.     

Metabolite assignment of ultrafiltered synovial fluid extracted from knee joints of reactive arthritis patients using high resolution NMR spectroscopy

Currently, there are no reliable biomarkers available that can aid early differential diagnosis of reactive arthritis (ReA) from other inflammatory joint diseases. Metabolic profiling of synovial fluid (SF)—obtained from joints affected in ReA—holds great promise in this regard and will further aid monitoring treatment and improving our understanding about disease mechanism. As a first step in this direction, we report here the metabolite specific assignment of ¹H and ¹³C resonances detected in the NMR spectra of SF samples extracted from human patients with established ReA. The metabolite characterization has been carried out on both normal and ultrafiltered (deproteinized) SF samples of eight ReA patients (n = 8) using high-resolution (800 MHz) ¹H and ¹H─¹³C NMR spectroscopy methods such as one-dimensional ¹H CPMG and two-dimensional J-resolved¹H NMR and homonuclear ¹H─¹H TOCSY and heteronuclear¹H─¹³C HSQC correlation spectra. Compared with normal SF samples, several distinctive ¹H NMR signals were identified and assigned to metabolites in the ¹H NMR spectra of ultrafiltered SF samples. Overall, we assigned 53 metabolites in normal filtered SF and 64 metabolites in filtered pooled SF sample compared with nonfiltered SF samples for which only 48 metabolites (including lipid/membrane metabolites as well) have been identified. The established NMR characterization of SF metabolites will serve to guide future metabolomics studies aiming to identify/evaluate the SF-based metabolic biomarkers of diagnostic/prognostic potential or seeking biochemical insights into disease mechanisms in a clinical perspective.     

Amidase and peptidase activities of polyclonal immunoglobulin G present in the sera of patients with rheumatoid arthritis

Polyclonal Immunoglobulin (Ig) G from patients with rheumatoid arthritis (RA) and healthy subjects hydrolyzed carbobenzoxy−Val−Gly−Arg p-nitroanilide and D−Pro−Phe−Arg p-nitroanilide. RA IgG exhibited higher activity against the former substrate, but not the latter. On the other hand, RA IgG showed reduced activity against D−Pro−Phe−Arg methylcoumarinamide, when compared with those of the healthy controls. These results suggest that RA IgGs differ from normal IgGs in the substrate specificity of amidase activity. Preliminary studies have shown that two out of three RA IgG samples cleaved a pentapeptide—Gln−Arg−Arg−Arg−Ala−Ala— which is assumed to be associated with the risk of developing RA (Gregersen, P. K. et al. (1987), Arthritis Rheum. 30, 1205–1213). By contrast, virtually no cleavage of the same peptide was observed with IgG from healthy controls. A peptide analog, Gln−Arg−Arg−Trp−Ala, was not cleaved at all by any IgGs examined either from RA patients or healthy controls.     

Metabolic characteristics and pharmacokinetic differences of Qiwei Tongbi oral liquid in rheumatoid arthritis rats

Qiwei Tongbi oral liquid (QWTB), a classical traditional Chinese medicine formula, is widely used to treat arthritis-related diseases in clinical practice. Currently, in vivo metabolic characteristics and pharmacokinetic studies are lacking. This study analyzed the prototype components of QWTB absorbed in the blood and their metabolic transformation process after intragastric administration and compared the differences in pharmacokinetic properties between healthy and rheumatoid arthritis model rats. In sum, 17 prototype components and 21 related metabolites were identified in the plasma and urine of the treated rats. Metabolites were derived from sinomenine and magnoflorine. Through systematic methodology verification, an accurate and stable detection method for sinomenine and magnoflorine in plasma samples was established and applied to pharmacokinetic research of QWTB. At the three dose levels, the AUC_0–∞ (area under the curve) of the two components showed a good positive correlation with the dose (R² > 0.9). Compared with healthy rats, the T_max, t_1/2z, and AUC of sinomenine were markedly increased, and C_max was decreased in rheumatoid arthritis model rats, indicating that the rate of absorption and elimination rate decreased, but the body exposure increased. However, there were no significant differences in the pharmacokinetic parameters of magnoflorine under healthy and pathological conditions. In summary, the main active ingredients of QWTB are sinomenine and magnoflorine, which exhibit linear kinetic characteristics within a set dose range, and the rheumatoid arthritis pathological state is more conducive to the absorption and efficacy of sinomenine. The results of this study demonstrate the rationality of the clinical application of the QWTB.     

Obesity aggravates the joint inflammation in a collagen-induced arthritis model through deviation to Th17 differentiation

White fat cells secrete adipokines that induce inflammation and obesity has been reported to be characterized by high serum levels of inflammatory cytokines such as IL-6 and TNF-α. Rheumatoid arthritis (RA) is a prototype of inflammatory arthritis, but the relationship between RA and obesity is controversial. We made an obese inflammatory arthritis model: obese collagen-induced arthritis (CIA). C57BL/6 mice were fed a 60-kcal high fat diet (HFD) from the age of 4 weeks and they were immunized twice with type II collagen (CII). After immunization, the obese CIA mice showed higher arthritis index scores and histology scores and a more increased incidence of developing arthritis than did the lean CIA mice. After treatment with CII, mixed lymphocyte reaction also showed CII-specific response more intensely in the obese CIA mice than lean CIA. The anti-CII IgG and anti-CII IgG2a levels in the sera of the obese CIA mice were higher than those of the lean CIA mice. The number of Th17 cells was higher and the IL-17 mRNA expression of the splenocytes in the obese CIA mice was higher than that of the lean CIA mice. Obese CIA mice also showed high IL-17 expression on synovium in immunohistochemistry. Although obesity may not play a pathogenic role in initiating arthritis, it could play an important role in amplifying the inflammation of arthritis through the Th1/Th17 response. The obese CIA murine model will be an important tool when we investigate the effect of several therapeutic target molecules to treat RA.     

The role of adiponectin in the production of IL-6, IL-8, VEGF and MMPs in human endothelial cells and osteoblasts: implications for arthritic joints

This study was performed to evaluate the contribution of adiponectin to the production of interleukin (IL)-6, IL-8, vascular endothelial growth factor (VEGF), matrix metalloproteinase (MMP)-1 and MMP-13 in human endothelial cells and osteoblasts in arthritic joints. Cultured human umbilical vascular endothelial cells (HUVECs) and osteoblasts were stimulated with adiponectin (1 or 10 μg ml⁻¹) or IL-1β (0.1 ng ml⁻¹) in the presence or absence of hypoxia for 24 h. The protein expression patterns were examined by analyzing culture supernatants using the enzyme-linked immunosorbent assay (ELISA). Adiponectin significantly stimulated the production of VEGF, MMP-1 and MMP-13 in osteoblasts but not in endothelial cells, whereas it significantly stimulated the production of IL-6 and IL-8 in both endothelial cells and osteoblasts. The increase in VEGF production induced by adiponectin was significantly greater than that induced by IL-1β. The production of IL-6 and IL-8 in adiponectin-stimulated endothelial cells was approximately 10-fold higher than that in IL-1β-stimulated endothelial cells; in osteoblasts, adiponectin-induced IL-6 and IL-8 secretion was approximately twofold higher than that induced by IL-1β. In addition, IL-8 production in endothelial cells was approximately sevenfold higher than in osteoblasts. However, IL-6 levels were similar between the two cell types, suggesting that adiponectin may be involved in the production of IL-8 in endothelial cells, which may have an important role in neutrophil recruitment to arthritic joints. Furthermore, the increases in protein expression induced by adiponectin were differentially regulated by hypoxia. In conclusion, adiponectin has a more important role than does IL-1β in the production of mediators that drive synovitis and joint destruction in endothelial cells and osteoblasts at physiological concentrations.     

Common variants at the promoter region of the APOM confer a risk of rheumatoid arthritis

Although the genetic component in the etiology of rheumatoid arthritis (RA) has been consistently suggested, many novel genetic loci remain to uncover. To identify RA risk loci, we performed a genome-wide association study (GWAS) with 100 RA cases and 600 controls using Affymetrix SNP array 5.0. The candidate risk locus (APOM gene) was re-sequenced to discover novel promoter and coding variants in a group of the subjects. Replication was performed with the independent case-control set comprising of 578 RAs and 711 controls. Through GWAS, we identified a novel SNP associated with RA at the APOM gene in the MHC class III region on 6p21.33 (rs805297, odds ratio (OR) = 2.28, P = 5.20 × 10-7). Three more polymorphisms were identified at the promoter region of the APOM by the re-sequencing. For the replication, we genotyped the four SNP loci in the independent case-control set. The association of rs805297 identified by GWAS was successfully replicated (OR = 1.40, P = 6.65 × 10-5). The association became more significant in the combined analysis of discovery and replication sets (OR = 1.56, P = 2.73 × 10-10). The individuals with the rs805297 risk allele (A) at the promoter region showed a significantly lower level of APOM expression compared with those with the protective allele (C) homozygote. In the logistic regressions by the phenotype status, the homozygote risk genotype (A/A) consistently showed higher ORs than the heterozygote one (A/C) for the phenotype-positive RAs. These results indicate that APOM promoter polymorphisms are significantly associated with the susceptibility to RA.     

Synthesis,Characterization and Control of Proportion of Polymorph C in ITQ-16 and ITQ-17 Films

Continuous ITQ-16 and ITQ-17 films on silicon wafer were prepared in fluoride media using TEAOH as organic structure-directing agent. The proportion of polymorph C in the as-synthesized ITQ-16 and ITQ-17 films was determined via X-ray diffraction characterization. The proportion of polymorph C in the ITQ-16 and ITQ-17 films was controlled via optimizing the compositions of the reaction mixtures and reaction conditions, such as varying the Si/Ge molar ratio and adding n-propyl alcohol as a solvent in the reaction mixture. The Ge atoms in the reaction media strongly increased the crystallization of polymorph C in ITQ-16 and ITQ-17 films. Moreover, the stabilizing and buffering effect of n-propyl alcohol on crystal growth further enhanced the proportion of polymorph C in the ITQ-16 and ITQ-17 films. For potential catalytic applications, Al was incorporated into the framework of polymorph C, and a pure phase of polymorph C in Al-ITQ-17 film was achieved from the synthesis gel in the n-propyl alcohol phase.     

Uncovering the effective substances and mechanism of Ipomoea pes-caprae against rheumatoid arthritis using liquid chromatography-mass spectrometry and targeted network pharmacology

Ipomoea pes-caprae (L.) R. Br (Convolvulaceae) is a commonly used marine traditional Chinese medicine in the southern coastal areas of China. It has been widely used to treat rheumatoid arthritis, but its effective substances and anti-rheumatoid arthritis mechanism remain ambiguous. Hence, in this study, the chemical profile and absorbed ingredients of Ipomoea pes-caprae were elucidated by ultra-performance liquid chromatography-mass spectrometry. Moreover, targeted network pharmacology was used to clarify the mechanism of action of Ipomoea pes-caprae in treating rheumatoid arthritis. Finally, 23 compounds were identified in the aqueous extracts of Ipomoea pes-caprae and 12 absorbed ingredients were detected in rats' plasma. These 12 absorbed ingredients might be the essential effective substances of Ipomoea pes-caprae. The tissue distributions of 3 absorbed ingredients in rats were successfully analyzed. The targeted network pharmacological analysis results indicated that the regulation of inflammatory reaction, immune response, cell proliferation, and apoptosis were the critical mechanism of Ipomoea pes-caprae against rheumatoid arthritis. This study successfully clarified the effective substances and potential mechanisms of Ipomoea pes-caprae in treating rheumatoid arthritis. The results of this research could provide a valuable reference for further scientific research and clinical application.     

The influence of alpha1-acid glycoprotein on collagenase-3 activity in early rheumatoid arthritis

The concentration and glycosylation of alpha(1)-acid glycoprotein (AGP) alter significantly during inflammation. A definitive physiological role for AGP remains elusive and is the subject of extensive investigation. This study investigated the influence of AGP on the activity of collagenase-3, an important mediator of cartilage destruction in rheumatoid arthritis. AGP was isolated from normal and rheumatoid plasma. Fucosylation was determined by high pH anion-exchange chromatography; sialylation was assessed following enzymatic digest. Rheumatoid AGP displayed elevated fucosylation and sialylation compared with normal. The influence of each sample on collagenase-3 activity was measured fluorometrically. AGP influenced collagenase-3 catalysis and collagen binding, with catalytic activity correlating with fucosylation. Rheumatoid AGP exhibited less efficient inhibition than normal plasma AGP. It is hypothesized that AGP within rheumatoid synovial fluid may be inadequate to prevent excessive cartilage destruction and hence may exacerbate the disease process.     

Molecular mechanism of Xiaohuoluo wan for rheumatoid arthritis by integrating in vitro and in vivo chemomics and network pharmacology

The cause of rheumatoid arthritis (RA) is unclear. Xiaohuoluo wan (XHLW) is a classical Chinese medicine that is particularly effective in the treatment of RA. Given the chemical composition of XHLW at the overall level has been little studied and the molecular mechanism for the treatment of RA is not clear, we searched for the potential active compounds of XHLW and explored their anti-inflammatory mechanism in the treatment of RA by flexibly integrating the high-resolution ultra-performance liquid chromatography–mass spectrometry (UPLC–MS)-based in vitro and in vivo chemomics, network pharmacology, and other means. The results of the study identified that the active compounds of XHLW, such as alkaloids, nucleosides, and fatty acids, may play an anti-inflammatory role by regulating key targets such as IL-2, STAT1, JAK3, and MAPK8, inducing immune response through IL-17 signaling pathway, T-cell receptor, FoxO, tumor necrosis factor (TNF), and so forth, inhibiting the release of inflammatory factors and resisting oxidative stress and other pathways to treat RA. The results of this study provide referable data for the screening of active compounds and the exploration of molecular mechanisms of XHLW in the treatment of RA.