Immunochemical and enzymatic study of ceruloplasmin in rheumatoid arthritis

Forty adult patients (30 women and 10 men) with rheumatoid arthritis (RA), treated with nonsteroidal anti-inflammatory drugs, were studied. Serum levels of immunoreactive ceruloplasmin, oxidase activity of the ceruloplasmin and total copper, as well as the specific oxidase activity (enzyme activity per unit of mass) and the copper/immunoreactive ceruloplasmin relationship were significantly higher in the group of patients than in the healthy control group (p < 0.001). However, no significant difference was found for the concentration of non-ceruloplasmin copper between both groups. A statistically significant negative correlation was obtained for the concentration of serum thiobarbituric acid-reacting substances with the immunoreactive ceruloplasmin and its oxidase activity in the group of patients (p < 0.005). These results suggest that in RA increases of serum copper are produced at the expense of the fraction linked to the ceruloplasmin, diminishing the proportion of apoceruloplasmin and other forms poor in copper. Although the increase in the serum concentration of ceruloplasmin might offer an additional safeguard against oxidative stress. it does not appear to have a beneficial effect upon the activity of the illness as evaluated by means the biological inflammation markers C-reactive protein, erythrocyte sedimentation rate and sialic acid.     

Filifactor alocis and Dialister pneumosintes in a Mexican population affected by periodontitis and rheumatoid arthritis: An exploratory study

Filifactor alocis and Dialister pneumosintes have been associated with the initiation and progression of periodontitis (PE). We determined and compared the frequency of both bacteria in patients with PE, rheumatoid arthritis (RA), and PE/RA simultaneously. Detection was performed by polymerase chain reaction in the subgingival biofilm. Bacteria were more frequent in patients with PE, and clinical periodontal parameters such as pocket depth (PD) and clinical attachment loss (CAL) were significantly higher in patients with PE/RA. F. alocis and D. pneumosintes could influence PD and CAL, hence participating in the initiation and progression of PE in patients with RA.     

RGS1 silencing inhibits the inflammatory response and angiogenesis in rheumatoid arthritis rats through the inactivation of Toll-like receptor signaling pathway

Emerging evidence shows that rheumatoid arthritis (RA) progression can be induced by the activation of Toll-like receptor (TLR) signaling pathway. Regulator of G-protein signaling 1 (RGS1) is observed to be a candidate biomarker for arthritis. Accordingly, the present study aims to determine the potential effects of RGS1 mediating TLR on RA. A rat model of collagen-induced arthritis (CIA) was established to mimic the features of RA by injection of bovine type II collagen. The rats with CIA were treated with short hairpin RNA (shRNA) against RGS1 or TLR pathway activator Poly I:C to elucidate the role of RGS1 in RA progression. The inflammatory factors were measured, and the thoracic gland and spleen indexes as well as the vascular density were determined. The expression levels of RGS1, TLR3, vascular endothelial growth factor (VEGF), metalloproteinase-2 (MMP-2), MMP-9, and interleukin 1 receptor-associated kinase-4 (IRAK4) were determined. RGS1 was robustly increased in RA. The TLR signaling pathway was suppressed by RGS1 silencing. shRNA-mediated depletion of RGS1 was shown to significantly enhance thoracic gland index and inhibit the serum levels of TNF-α, IL-1β, and IL-17, spleen index, vascular density, and the expression levels of TLR3, VEGF, MMP-2, MMP-9, and IRAK4. However, when the rats with CIA were treated with Poly I:C, the trend of effects was opposite. These findings highlight that functional suppression of RGS1 inhibits the inflammatory response and angiogenesis by inactivating the TLR signaling pathway in rats with CIA, thereby providing a novel therapeutic target for RA treatment.     

Lipopolysaccharide accelerates collagen‐induced arthritis in association with rapid and continuous production of inflammatory mediators and anti‐type II collagen antibody

Collagen‐induced arthritis (CIA) is an animal model for rheumatoid arthritis (RA). Lipopolysaccharide (LPS) is known to accelerate CIA; however, the pathogenetic mechanisms are not yet fully understood. In this study, type II collagen (CII)‐immunized mice were found to have marked increases in degree of expression of mRNA of inflammatory mediators such as tumor necrosis factor alpha (TNF‐α), interleukin (IL)‐1β, and macrophage inflammatory protein‐2 (MIP‐2) in their arthritic paws and of serum anti‐CII antibody concentration before the onset of arthritis induced by LPS injection. The gene expression was rapid and continuous after direct activation of nuclear factor κB. The amounts of mRNA of TNF‐α, IL‐1β, and MIP‐2, as well as of matrix metalloproteinases and the receptor activator of nuclear factor κB ligand, increased with the development of arthritis, correlated positively with clinical severity and corresponded with histopathological changes. Moreover, anti‐TNF‐α neutralizing antibody inhibited the development of LPS‐accelerated CIA and a single injection of recombinant mouse TNF‐α induced increases in anti‐CII antibody concentrations, suggesting TNF‐α may contribute to the development of arthritis by both initiation of inflammation and production of autoantibodies. These data suggest that exacerbation of RA by LPS is associated with rapid and continuous production of inflammatory mediators and autoantibodies.     

Etiological role of cigarette smoking in rheumatoid arthritis: Nasal exposure to cigarette smoke condensate extracts augments the development of collagen-induced arthritis in mice

Cigarette smoking is a major environmental risk factor for rheumatoid arthritis (RA). However, the experimental bases supporting the etiological role of cigarette smoking in RA have not been fully provided. We have reported that cigarette smoke condensate (CSC), by means of subcutaneous injection into DBA/1J mice with collagen and complete Freund’s adjuvant or intraperitoneal injection one day before immunization, augmented the development of arthritis in the mouse model of collagen type II-induced arthritis (CIA). However, these experimental procedures may not be appropriate for cigarette smoking. In this study, we nasally exposed mice to mainstream CSC and found that CSC augmented the induction and development of arthritis and antibody level against collagen. Histological examination confirmed the augmenting effect of CSC. These findings provide experimental bases supporting the etiological role of cigarette smoking in RA.     

Effects of disease modifying agents and dietary intervention on insulin resistance and dyslipidemia in inflammatory arthritis: a pilot study

Patients with rheumatoid arthritis (RA) experience excess cardiovascular disease (CVD). We investigated the effects of disease-modifying antirheumatic drugs (DMARD) and dietary intervention on CVD risk in inflammatory arthritis. Twenty-two patients (17 women; 15 with RA and seven with spondyloarthropathy) who were insulin resistant (n = 20), as determined by the Homeostasis Model Assessment, and/or were dyslipidemic (n = 11) were identified. During the third month after initiation of DMARD therapy, body weight, C-reactive protein (CRP), insulin resistance, and lipids were re-evaluated. Results are expressed as median (interquartile range). DMARD therapy together with dietary intervention was associated with weight loss of 4 kg (0–6.5 kg), a decrease in CRP of 14% (6–36%; P < 0.006), and a reduction in insulin resistance of 36% (26–61%; P < 0.006). Diet compliers (n = 15) experienced decreases of 10% (0–20%) and 3% (0–9%) in total and low-density lipoprotein cholesterol, respectively, as compared with increases of 9% (6–20%; P < 0.05) and 3% (0–9%; P < 0.05) in diet noncompliers. Patients on methotrexate (n = 14) experienced a reduction in CRP of 27 mg/l (6–83 mg/l), as compared with a decrease of 10 mg/l (3.4–13 mg/l; P = 0.04) in patients not on methotrexate. Improved cardiovascular risk with DMARD therapy includes a reduction in insulin resistance. Methotrexate use in RA may improve CVD risk through a marked suppression of the acute phase response. Dietary intervention prevented the increase in total and low-density lipoprotein cholesterol upon acute phase response suppression.     

Suppressive effect of Withania somnifera root powder on experimental gouty arthritis: An in vivo and in vitro study

The effect of Withania somnifera L. Dunal root powder on paw volume and serum lysosomal enzyme activities was investigated in monosodium urate crystal-induced rats. The levels of beta-glucuronidase and lactate dehydrogenase were also measured in monosodium urate crystal incubated polymorphonuclear leucocytes (PMNL). A significant increase in the level of paw volume and serum lysosomal enzymes was observed in monosodium urate crystal-induced rats. The increased beta-glucuronidase and lactate dehydrogenase level were observed in untreated monosodium urate crystal incubated polymorphonuclear leucocytes. On treatment with the W. somnifera root powder (500/1000 mg/kg body weight), the above changes were reverted back to near normal levels. W. somnifera also showed potent analgesic and antipyretic effect with the absence of gastric damage at different dose levels in experimental rats. For comparison purpose, non-steroidal anti-inflammatory drug (NSAID) indomethacin was used as a standard. These results provide evidence for the suppressive effect of W. somnifera root powder by retarding amplification and propagation of the inflammatory response without causing any gastric damage.     

Spatial dependence modeling of latent susceptibility and time to joint damage in psoriatic arthritis

Important scientific insights into chronic diseases affecting several organ systems can be gained from modeling spatial dependence of sites experiencing damage progression. We describe models and methods for studying spatial dependence of joint damage in psoriatic arthritis (PsA). Since a large number of joints may remain unaffected even among individuals with a long disease history, spatial dependence is first modeled in latent joint-specific indicators of susceptibility. Among susceptible joints, a Gaussian copula is adopted for dependence modeling of times to damage. Likelihood and composite likelihoods are developed for settings, where individuals are under intermittent observation and progression times are subject to type K interval censoring. Two-stage estimation procedures help mitigate the computational burden arising when a large number of processes (i.e., joints) are under consideration. Simulation studies confirm that the proposed methods provide valid inference, and an application to the motivating data from the University of Toronto Psoriatic Arthritis Clinic yields important insights which can help physicians distinguish PsA from arthritic conditions with different dependence patterns.     

Sulforaphene targets NLRP3 inflammasome to suppress M1 polarization of macrophages and inflammatory response in rheumatoid arthritis

This work aimed to explore the therapeutic effect and target of sulforaphene (LF) in mice with rheumatoid arthritis (RA). Lipopolysaccharide (LPS) and IFN-γ were added to induce the M1 polarization of SMG cells, and later cells were pretreated with 5 μM and 15 μM LF. M1 cell proportion was detected by flow cytometry (FCM), inflammatory factors were measured by enzyme-linked immunosorbent assay, and protein levels were analyzed by western blotting (WB) assay. Besides, small molecule-protein docking and pull-down assays were carried out to detect the binding of LF to NLRP3. After the knockdown of NLRP3 in SMG cells, the effect of LF was further detected. The RA mouse model was induced with collagen antibody and LPS, after LF intervention, H&E staining was performed to detect the pathological changes in mouse synovial membrane, whereas safranin O-fast green staining was performed to detect cartilage injury, NLRP3 inflammasome and inflammatory factor levels in tissues. LF suppressed M1 polarization of macrophages, reduced M1 cell proportion and inflammatory factor levels, and suppressed the activation of NLRP3 inflammasome. After NLRP3 knockdown, LF did not further suppress the M1 polarization of macrophages. Pull-down assay suggested that LF bound to NLRP3. As revealed by mouse experimental results, LF inhibited bone injury in mice, decreased M1 cell infiltration and inflammatory response in tissues, and inhibited NLRP3 inflammasome expression in tissues. LF targets NLRP3 to suppress the M1 polarization of macrophages and decrease tissue inflammation in RA.     

Analysis of subgingival microbiome of periodontal disease and rheumatoid arthritis in Chinese: A case-control study

ObjectivePeriodontitis (PD) and rheumatoid arthritis (RA) share similar pathogenesis. Evidences indicated that oral bacteria play an important role in the etiology of both diseases. For example, Porphyromonas gingvialis connect the two diseases through immune responses. We designed this study to compare bacterial diversity in RA, PD and healthy subjects and to investigate whether there are other oral bacteria play an potential role in linking the two diseases.MethodsThis study included 3 groups of Chinese participants who visited Sichuan Provincial People’s Hospital during August 2018 and March 2019. Subgingival plaques were collected from RA group (n = 54), PD group (n = 45) and normal group (n = 44). Illumina MiSeq was used to compare the composition of subgingival microbiota and analyze correlations between oral bacteria and both diseases.ResultsAlpha diversity Analysis reflected similar microbiome profile in RA, PD and healthy groups. But we found Treponema was significantly more abundant in the PD and RA groups than healthy group at each taxonomic level from the phylum down to the genus level. Porphyromonas, Prevotella, and Veilonella were significantly more abundant in RA while Streptococcus, Gemella, Planobacterium were verified the opposite results.ConclusionsWe found no significant group differences referent to either microbial diversity or richness. But we picked out Spirochaetes which may link the two diseases. Upper/lower regulation of some microbia in RA may remind us a direction to explore the role they play in pathogenesis.     

A combination of cellular biomarkers predicts failure to respond to rituximab in rheumatoid arthritis: a 24-week observational study

BackgroundAlthough B cell depletion with rituximab (RTX) is an effective treatment strategy in rheumatoid arthritis (RA), one third of patients do not achieve remission or low disease activity (LDA). Thus, identifying patients who will benefit from RTX is highly desirable. In the present study we investigated whether lymphocyte subsets other than B cells are predictors of a clinical response to RTX treatment.MethodsPatients with RA who were receiving RTX for the first time were included in an observatory registry. Clinical assessments, complete blood count and flow cytometry of lymphocyte subsets were obtained at baseline and at week 24 after RTX. Complete data were available for 44 patients. Logistic regression and receiver operating characteristic curve analyses were computed to analyze the predictive value of lymphocyte subsets for European League Against Rheumatism (EULAR) response and LDA (defined as disease activity score in 28 joints (DAS28) ≤3.2) at week 24.ResultsEULAR responders had lower total lymphocyte counts (LC), T cells and CD4 + T cells at baseline. Although these parameters were independent predictors of EULAR response they failed in determining who would reach LDA. In contrast, LC >2910/μl or plasmablast frequency >2.85 % at baseline predicted a significantly higher DAS28 at week 24 after RTX and identified patients not achieving LDA at week 24 with sensitivity of 93.3 % and specificity of 44.8 %.ConclusionsA combination of LC and plasmablast frequency identifies patients with RA who will not benefit from RTX with high probability.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1091-1) contains supplementary material, which is available to authorized users.     

Dietary n-3 fats as adjunctive therapy in a prototypic inflammatory disease: issues and obstacles for use in rheumatoid arthritis

Eicosanoids derived from the n-6 fatty acid, arachidonic acid, and the cytokines interleukin-1beta and tumour necrosis factor-alpha are involved in the signs and symptoms of inflammatory joint disease, as well as the cartilage degradation seen in established rheumatoid arthritis (RA). Then n-3 fatty acids in fish and fish oil can inhibit production of both eicosanoid and cytokine inflammatory mediators and therefore, have the potential to modify RA pathology. Epidemiological studies suggest that fish intake may be preventive for RA and double-blind placebo-controlled studies demonstrate that dietary fish oil can alleviate the signs and symptoms of RA. The implementation of these findings will require among other things, a range of n-3 fat enriched foods, as well as physician awareness of the possibilities for dietary n-3 fat increases to be used as adjunctive therapy in RA.     

Possible relationship between periodontitis and dementia in a North Indian old age population: a pilot study

doi: 10.1111/j.1741‐2358.2010.00441.x Possible relationship between periodontitis and dementia in a North Indian old age population: a pilot study Background: Periodontitis and cognitive impairment or dementia is relatively common among older adults. Few cross‐sectional studies and some longitudinal studies have attempted to link oral health with dementia diagnosis or disease pathology but none has investigated the role of inflammation as a potential mediator. Objectives: This study was planned to establish a relation of inflammatory mediators between periodontitis and dementia. Materials and methods: Fifty‐five patients with severe periodontitis (range 60–69 years), 20 with dementia (10:10 M:F; range 59–69) and 32 healthy controls (range 58–69 years) were selected. The socio‐demographic characteristics, physical health, oral health, education status, and medical status were measured. Serum C‐reactive protein (CRP), matrix metalloproteinase (MMP)‐8, MMP‐9, total IGF‐I, free IGF‐I and TNF‐alpha and GCF MMP‐8 &MMP‐9 were calculated. Results: There was no significant difference between the three groups in the level of education, age, occupation, BMI, CAD, CHF and diabetes except dentate status. After adjusting for age, significant differences were found between patients and controls with respect to gingival inflammation, dental plaque, bleeding on probing and probing pocket depth. Total counts of WBCs, neutrophils, thrombocytic counts and serum CRP, MMP‐8, MMP‐9, TNF‐alpha levels were significantly higher in dementia and periodontitis patients in contrast to healthy controls, while, RBC counts, total IGF‐I and Hb levels were lowered in dementia and periodontitis patients in comparison to healthy controls, although higher in dementia as compared to periodontitis patients. Conclusions: This study data suggest a relationship of inflammatory mediators between periodontitis and dementia. Further exploration of this is warranted.     

Use of a whole-slide imaging system to assess the presence and alteration of lymphatic vessels in joint sections of arthritic mice

Abstract

We investigated the presence and alteration of lymphatic vessels in joints of arthritic mice using a whole-slide imaging system. Joints and long bone sections were cut from paraffin blocks of two mouse models of arthritis: meniscal-ligamentous injury (MLI)-induced osteoarthritis (OA) and TNF transgene (TNF-Tg)-induced rheumatoid arthritis (RA). MLI-OA mice were fed a high fat diet to accelerate OA development. TNF-Tg mice were treated with lymphatic growth factor VEGF-C virus to stimulate lymphangiogenesis. Sections were double immunofluorescence stained with anti-podoplanin and alpha-smooth muscle actin antibodies. The area and number of lymphatic capillaries and mature lymphatic vessels were determined using a whole-slide imaging system and its associated software. Lymphatic vessels in joints were distributed in soft tissues mainly around the joint capsule, ligaments, fat pads and muscles. In long bones, enriched lymphatic vessels were present in the periosteal areas adjacent to the blood vessels. Occasionally, lymphatic vessels were observed in the cortical bone. Increased lymphatic capillaries, but decreased mature lymphatic vessels, were detected in both OA and RA joints. VEGF-C treatment increased lymphatic capillary and mature vessel formation in RA joints. Our findings suggest that the lymphatic system may play an important role in arthritis pathogenesis and treatment.     

Sialyl Lewisx expression on IgG in rheumatoid arthritis and other arthritic conditions: a preliminary study

Both infiltrating leukocytes and soluble immunoglobulin form aggregates in synovial fluid during the inflammatory process in rheumatoid arthritis (RA). Some of these changes are probably mediated by the adhesion molecule, E-selectin, which increases its expression with disease activity. As glycosylation changes in IgG in RA are well established, the current study was undertaken to measure the expression of the carbohydrate antigen sialyl Lewis x (sLe^x), on IgG in RA. sLe^x is a major ligand for E-selectin. Using a recently developed ELISA, sLe^x expression was determined in IgG isolated from 8 healthy individuals, 20 RA sufferers (10 early and 10 with more long-standing disease) and 20 patients with other rheumatic conditions (osteoarthritis, ankylosing spondylitis, systemic lupus erythematosus). S Le^xexpression on IgG was elevated above the reference range in all but one of the RA patients and this change was highly significant (P < 0.0006). Expression of this antigen on IgG was also significantly different from normal in the other arthritic groups (P < 0.02), but the changes were much less than that observed for RA. In early RA, sLe^x was inversely correlated with parameters used to measure disease activity. This was not observed with the established RA, where there was weak positive association. These preliminary results indicate that a change in sLe^x expression on IgG is an early finding in the development of RA, which may be important in the development of the disease or for predicting its outcome.     

An Adipose Tissue Atlas: An Image-Guided Identification of Human-like BAT and Beige Depots in Rodents

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Effect of sclerostin-neutralising antibody on periarticular and systemic bone in a murine model of rheumatoid arthritis: a microCT study

Introduction

Patients with chronic inflammatory diseases have increased bone loss and bone fragility and are at increased risk of fracture. Although anti-resorptive drugs are effective in blocking inflammation-induced bone loss, they are less effective at rebuilding bone. We have previously shown that treatment with sclerostin antibody (Scl-AbI) builds bone and can prevent or restore bone loss in a murine model of inflammatory bowel disease. In this study, we tested the effect of Scl-AbI in a murine model of rheumatoid arthritis (the collagen-induced arthritis model, CIA). We hypothesised that sclerostin blockade can protect and restore bone both locally and systemically without affecting progression of inflammation.

Methods

CIA was induced in male DBA/1 mice, which were treated with either PBS or Scl-AbI (10 mg/kg, weekly) prophylactically for 55 days or therapeutically for 21 days (starting 14 days post onset of arthritis). Systemic inflammation was assessed by measuring the serum concentration of anti-CII IgG1, IgG2a and IgG2b by ELISA. Changes in bone mass and structure, either at sites remote from the joints or at periarticular sites, were measured using DEXA and microCT. Bone focal erosion was assessed in microCT scans of ankle and knee joints.

Results

Circulating anti-CII immunoglobulins were significantly elevated in mice with CIA and there were no significant differences in the levels of anti-CII immunoglobulins in mice treated with PBS or Scl-ABI. Prophylactic Scl-AbI treatment prevented the decrease in whole body bone mineral density (BMD) and in the bone volume fraction at axial (vertebral body) and appendicular (tibial proximal metaphysis trabecular and mid-diaphysis cortical bone) sites seen in PBS-treated CIA mice, but did not prevent the formation of focal bone erosions on the periarticular bone in the knee and ankle joints. In the therapeutic study, Scl-AbI restored BMD and bone volume fraction at all assessed sites but was unable to repair focal erosions.

Conclusions

Sclerostin blockade prevented or reversed the decrease in axial and appendicular bone mass in the murine model of rheumatoid arthritis, but did not affect systemic inflammation and was unable to prevent or repair local focal erosion.     

Genomics and transcriptomics to study fruiting body development: An update

Fruiting bodies of asco- and basidiomycetes are complex three-dimensional structures that protect and disperse the sexual spores. Their differentiation requires the concerted action of many genes, therefore "omics" techniques to analyze fungal genomes and gene expression at a genome-wide level provide excellent means to gain insights into this differentiation process. This review summarizes some recent examples of the use of “omics” techniques to study fruiting body morphogenesis. These include genome-centered analyses, and studies to analyze the regulation of gene expression including the analysis of RNA editing as a novel layer in the regulation of gene expression during fruiting body development in ascomycetes.     

A novel robust and high-throughput method to measure cell death in Nicotiana benthamiana leaves by fluorescence imaging

Assessing immune responses and cell death in Nicotiana benthamiana leaf agro-infiltration assays is a powerful and widely used experimental approach in molecular plant pathology. Here, we describe a reliable high-throughput protocol to quantify strong, macroscopically visible cell death responses in N. benthamiana agro-infiltration assays. The method relies on measuring the reduction of leaf autofluorescence in the red spectrum upon cell death induction and provides quantitative data suitable for straightforward statistical analysis. Two different well-established model nucleotide-binding and leucine-rich repeat domain proteins (NLRs) were used to ensure the genericity of the approach. Its accuracy and versatility were compared to visual scoring of the cell death response and standard methods commonly used to characterize NLR activities in N. benthamiana. A discussion of the advantages and limitations of our method compared to other protocols demonstrates its robustness and versatility and provides an effective means to select the best-suited protocol for a defined experiment.