Association of soluble cell adhesion molecules and lipid levels in rheumatoid arthritis patients

Anti-arthritic potential of crude sulfated polysaccharide from marine macroalgae Sargassum ilicifolium (Turner) C. Agardh: Regulation of cytokine cascade

Seaweeds have been utilized as food, fodder, fertilizer, and medicine since ancient times; nevertheless, they have received only a little attention. In the current work, we extracted the sulfated polysaccharide from a marine source and investigated its anti-arthritic potential in vivo. The isolated and freeze-dried polysaccharide was tested for acute oral toxicity based on OECD 423. This step was followed by investigations on clinical signs and gross pathological alterations seen. A complete Freund's adjuvant-induced arthritis was used to test the in vivo activity in female Sprague-Dawley rats, which were divided into five groups: (1) normal control, (2) arthritic control, (3) methotrexate treatment (0.1 mg/kg), (4) crude sulfated polysaccharide (CSP) (5 mg/kg), and (5) CSP (10 mg/kg). CSP was from the marine brown algae Sargassum ilicifolium from the Gulf of Mannar. The body weight, paw volume, and biochemical markers (alanine aminotransferase, aspartate aminotransferase, creatinine, urea, and C-reactive protein levels) were also measured for each group coupled with histopathological and immunohistochemistry studies. The acute toxicity investigation indicated that the lethal dose of 50% (LD50) of the polysaccharide was more than 2,000 mg/kg. In addition, animals from the methotrexate and CSP (5 mg/kg, p.o.) groups had a substantial reduction in paw volume compared to other treatment groups. Methotrexate and CSP treatment dramatically decreased the levels of the investigated marker enzymes. Histopathology revealed that low-dose CSP (5 mg/kg, p.o.) significantly reduced the severity of synovitis, panniculitis, liver necrosis, inflammatory cell infiltration, and cortical and paracortical necrotic foci in node, compared to the high dose (10 mg/kg, p.o.). Immunohistochemical studies revealed that CSP (5 mg/kg) significantly inhibited pro-inflammatory cytokines such as tumor necrosis factor-alpha, interleukin-2, and CD4 cells. Overall, it can be concluded that a low-dose CSP (5 mg/kg) is an efficient anti-arthritic agent that confers its effects via the cytokine pathway.

Interleukin-6: Cardiovascular Aspects of Long-Term Cytokine Suppression in Patients with Rheumatoid Arthritis

In recent years, many atherogenesis researchers have focused on the role of inflammatory cytokines in the development of cardiovascular disease (CVD). Interleukin-6 (IL-6) cytokine is independently associated with higher CVD risk in patients with rheumatoid arthritis (RA). The effect of IL-6 inhibitors on the cardiovascular system in RA patients remains poorly understood, especially with its long-term use. This study investigates the effect of therapy with IL-6 receptor blocker tocilizumab (TCZ) on the dynamics of cardiovascular risk (CVR), modifiable risk factors (RFs), carotid artery (CA) structural changes, and the incidence of cardiovascular complications (CVCs) in RA patients during a 265-week follow-up period. Forty-five patients with active RA (DAS28-ESR 6.2 (5.5;6.8) with ineffectiveness and/or intolerance to disease-modifying antirheumatic drugs (DMARDs) were included in this study. During long-term therapy with TCZ in RA patients, no increase in CVR and no significant structural changes in CA were observed. No significant changes in the blood lipid spectrum were observed in patients without statin therapy. In the group of patients receiving statins, there was a 43% increase in high-density lipoprotein cholesterol (HDL-C), a 15% reduction in total cholesterol levels, and a 56% decrease in the atherogenicity index (p < 0.01 in all cases). Associations were found between ∆ total cholesterol and ∆ C-reactive protein (CRP) (R = 0.36, p = 0.04), ∆ low-density lipoprotein cholesterol (LDL-C), and ∆-CRP (R = 0.42, p = 0.03) in RA patients receiving statins. Initially, the thickness of the intima-media complex of carotid arteries (cIMT) positively moderately correlated with age (R = 0.7; p < 0.01), BMI (R = 0.37; p < 0.01), and systolic blood pressure (R = 0.64; p < 0.01); however, it weakly correlated with the lipid spectrum parameters: total cholesterol (R = 0.29; p < 0.01) and LDL-C (R = 0.33; p < 0.01). No new associations of cIMT by the end of the follow-up period, as well as the relationship of cIMT value with RA activity and therapy, were revealed. Patients with carotid ASPs showed an oppositely directed relationship between total cholesterol and sVCAM-1 at baseline (R = -0.25, p = 0.01) and at the end of this study (R = 0.29, p < 0.01). The incidence of cardiovascular events was 0.53 per 100 patient-years during the 265-week period of TCZ therapy.

Precise Lipidomics Decipher Circulating Ceramide and Sphingomyelin Cycle Associated with the Progression of Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a long-term autoimmune condition that causes joint and surrounding tissue inflammation. Lipid mediators are involved in inflammation and deterioration of the joints. Despite attempts to discover effective drug targets to intervene with lipid metabolism in the disease, progress has been limited. In this study, precise lipidomic technology was employed to quantify a broad range of serum ceramides and sphingomyelin (SM) in a large cohort, revealing an association between the accumulation of circulating ceramides and disturbed ceramide/SM cycles during the progression of RA. In our investigation, we discovered that eight ceramides exhibited a positive correlation with the activity of RA, thereby enhancing the accuracy of RA diagnosis, particularly in patients with serum antibody-negative RA. Furthermore, the enzyme SM phosphodiesterase 3 (SMPD3) was found to disrupt the circulating SM cycle and accelerate the progression of RA. The activity of SMPD3 can be inhibited by methotrexate, resulting in decreased metabolic conversion of SM to ceramide. These findings suggest that targeting the SM cycle may provide a new therapeutic option for RA.

Relevance of circulating markers of endothelial activation for cardiovascular risk assessment in rheumatoid arthritis: a narrative review

Rheumatoid arthritis (RA) is associated with excessive cardiovascular mortality secondary to premature atherosclerosis, in which endothelial activation (EA) plays a central role. EA is characterized by loss of vascular integrity, expression of leucocyte adhesion molecules, transition from antithrombotic to prothrombotic phenotype, cytokines production, shedding of membrane microparticles and recruitment of endothelial progenitor cells. As EA is an early event in atherogenesis, circulating markers of EA are putative markers of vascular pathology and cardiovascular (CV) risk. After a presentation of biology of EA, the present review analyzed the available data regarding changes in EA markers in RA in link with the vascular pathology and CV events, discussed their relevance as biomarkers of CV risk and proposed future directions.