The role of interleukin-6 trans-signalling on cardiovascular dysfunction in inflammatory arthritis

Shared inflammatory pathways of rheumatoid arthritis and atherosclerotic cardiovascular disease

The association between chronic inflammation and increased risk of cardiovascular disease in rheumatoid arthritis (RA) is well established. In the general population, inflammation is an established independent risk factor for cardiovascular disease, and much interest is placed on controlling inflammation to reduce cardiovascular events. As inflammation encompasses numerous pathways, the development of targeted therapies in RA provides an opportunity to understand the downstream effect of inhibiting specific pathways on cardiovascular risk. Data from these studies can inform cardiovascular risk management in patients with RA, and in the general population. This Review focuses on pro-inflammatory pathways targeted by existing therapies in RA and with mechanistic data from the general population on cardiovascular risk. Specifically, the discussions include the IL-1, IL-6 and TNF pathways, as well as the Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signalling pathway, and the role of these pathways in RA pathogenesis in the joint alongside the development of atherosclerotic cardiovascular disease. Overall, some robust data support inhibition of IL-1 and IL-6 in decreasing the risk of cardiovascular disease, with growing data supporting IL-6 inhibition in both patients with RA and the general population to reduce the risk of cardiovascular disease.

Integrative Mendelian randomization reveals the soluble receptor for advanced glycation end products as protective in relation to rheumatoid arthritis

Rheumatoid arthritis (RA) is a risk factor for atherosclerotic cardiovascular diseases (CVD). Given the critical roles of the immune system and inflammatory signals in the pathogenesis of CVD, we hypothesized that interrogation of CVD-related proteins using integrative genomics might provide new insights into the pathophysiology of RA. We utilized two-sample Mendelian randomization (MR) for causal inference between circulating protein levels and RA by incorporating genetic variants, followed by colocalization to characterize the causal associations. Genetic variants from three sources were obtained: those associated with 71 CVD-related proteins measured in nearly 7000 Framingham Heart Study participants, a published genome-wide association study (GWAS) of RA (19 234 cases, 61 565 controls), and GWAS of rheumatoid factor (RF) levels from the UK Biobank (n = 30 565). We identified the soluble receptor for advanced glycation end products (sRAGE), a critical inflammatory pathway protein, as putatively causal and protective for both RA (odds ratio per 1-standard deviation increment in inverse-rank normalized sRAGE level = 0.364; 95% confidence interval 0.342-0.385; P = 6.40 × 10-241) and RF levels (β [change in RF level per sRAGE increment] = - 1.318; SE = 0.434; P = 0.002). Using an integrative genomic approach, we highlight the AGER/RAGE axis as a putatively causal and promising therapeutic target for RA.

Accelerated atherosclerosis in rheumatoid arthritis: a systematic review

Background: Rheumatoid arthritis (RA) is a highly prevalent, chronic inflammatory condition of the synovial joints that affects approximately 1% of the global population. The pathogenesis of RA is predominantly inflammatory in nature, thereby accelerating the co-occurrence of other immunoinflammatory conditions such as atherosclerosis. Apart from traditional cardiovascular risk factors, RA patients possess a multitude of other factors that predispose them to early atherosclerotic disease. The aim of this systematic review is to assess the prevalence of premature atherosclerosis in RA patients and elucidate the role that proinflammatory cytokines, RA-related autoantibodies, and endothelial dysfunction play in the pathophysiology of RA-mediated atherosclerosis. We also discussed novel biomarkers that can be used to predict early atherosclerosis in RA and current guidelines used to treat RA. Methods: This review followed the PRISMA guidelines to select and analyze relevant articles. A literature search for articles was performed on February 25, 2022, through three research databases including PubMed, ProQuest, and ScienceDirect. The query used to identify relevant publications was "Rheumatoid arthritis and atherosclerosis" and the search duration was set from 2012-2022. Relevant articles were selected based on the inclusion and exclusion criteria. Results: Our initial search generated 21,235 articles. We narrowed our search according to the inclusion and exclusion criteria. After assessing eligibility based on the full content of the articles, 73 articles were ultimately chosen for this review. Conclusion: There is an increased prevalence of accelerated atherosclerosis among RA patients. We found evidence to explain the role of proinflammatory cytokines, RA-related autoantibodies, and endothelial dysfunction in the pathophysiology RA-mediated atherosclerosis. Therapies targeting either the inflammatory load or traditional CV risk-factors seem to improve vascular outcomes in RA patients. Novel markers of atherosclerosis in RA may be useful in predicting premature atherosclerosis and serve as new targets for therapeutic intervention.

Tracking Cardiovascular Comorbidity in Models of Chronic Inflammatory Disease

Immune-mediated inflammatory diseases (IMIDs) are commonly associated with complex coexisting conditions, and cardiovascular comorbidities are a common cause of mortality in systemic inflammation. Experimental models of disease provide an opportunity to dissect inflammatory mechanisms that promote damage to vascular tissues affected by comorbidity. Here, we describe methods to recover the thoracic aorta from mice during experimental inflammatory arthritis and assess vascular constriction responses by isometric tension myography. To complement the assessment of functional changes in the vasculature during inflammatory arthritis, we also outline a method to characterize vascular inflammation by immunohistochemistry.

Systemic complications of rheumatoid arthritis: Focus on pathogenesis and treatment

As a systemic autoimmune disease, rheumatoid arthritis (RA) usually causes damage not only to joints, but also to other tissues and organs including the heart, kidneys, lungs, digestive system, eyes, skin, and nervous system. Excessive complications are closely related to the prognosis of RA patients and even lead to increased mortality. This article summarizes the serious complications of RA, focusing on its incidence, pathogenesis, clinical features, and treatment methods, aiming to provide a reference for clinicians to better manage the complications of RA.

Non-pharmacological treatment in difficult-to-treat rheumatoid arthritis

Although the management of rheumatoid arthritis (RA) has improved remarkably with new pharmacological therapies, there is still a significant part of patients not reaching treatment goals. Difficult-to-treat RA (D2TRA) is a complex entity involving several factors apart from persistent inflammation, thereafter requiring a holistic management approach. As pharmacological treatment options are often limited in D2TRA, the need for non-pharmacological treatments (NPT) is even more pronounced. The mechanism of action of non-pharmacological treatments is not well investigated, NPTs seem to have a complex, holistic effect including the immune, neural and endocrine system, which can have a significant additive benefit together with targeted pharmacotherapies in the treatment of D2TRA. In this review we summarize the current knowledge on different NPT in rheumatoid arthritis, and we propose a NPT plan to follow when managing D2TRA patients.

Accelerated atherosclerosis in rheumatoid arthritis: a systematic review

Background: Rheumatoid arthritis (RA) is a highly prevalent, chronic inflammatory condition of the synovial joints that affects approximately 1% of the global population. The pathogenesis of RA is predominantly inflammatory in nature, thereby accelerating the co-occurrence of other immunoinflammatory conditions such as atherosclerosis. Apart from traditional cardiovascular risk factors, RA patients possess a multitude of other factors that predispose them to early atherosclerotic disease. The aim of this systematic review is to assess the prevalence of premature atherosclerosis in RA patients and elucidate the role that proinflammatory cytokines, RA-related autoantibodies, and endothelial dysfunction play in the pathophysiology of RA-mediated atherosclerosis. We also discussed novel biomarkers that can be used to predict early atherosclerosis in RA and current guidelines used to treat RA. Methods: This review followed the PRISMA guidelines to select and analyze relevant articles. A literature search for articles was performed on February 25, 2022, through three research databases including PubMed, ProQuest, and ScienceDirect. The query used to identify relevant publications was "Rheumatoid arthritis and atherosclerosis" and the search duration was set from 2012-2022. Relevant articles were selected based on the inclusion and exclusion criteria. Results: Our initial search generated 21,235 articles. We narrowed our search according to the inclusion and exclusion criteria. After assessing eligibility based on the full content of the articles, 73 articles were ultimately chosen for this review. Conclusion: There is an increased prevalence of accelerated atherosclerosis among RA patients. We found evidence to explain the role of proinflammatory cytokines, RA-related autoantibodies, and endothelial dysfunction in the pathophysiology RA-mediated atherosclerosis. Therapies targeting either the inflammatory load or traditional CV risk-factors seem to improve vascular outcomes in RA patients. Novel markers of atherosclerosis in RA may be useful in predicting premature atherosclerosis and serve as new targets for therapeutic intervention.

Treatment of Cardiovascular Disease in Rheumatoid Arthritis: A Complex Challenge with Increased Atherosclerotic Risk

Rheumatoid arthritis (RA) carries significant risk for atherosclerotic cardiovascular disease (ASCVD). Traditional ASCVD risk factors fail to account for this accelerated atherosclerosis. Shared inflammatory pathways are fundamental in the pathogenesis of both diseases. Considering the impact of RA in increasing cardiovascular morbidity and mortality, the characterization of therapies encompassing both RA and ASCVD management merit high priority. Despite little progress, several drugs discussed here promote remission and or lower rheumatoid disease activity while simultaneously conferring some level of atheroprotection. Methotrexate, a widely used disease-modifying drug used in RA, is associated with significant reduction in cardiovascular adverse events. MTX promotes cholesterol efflux from macrophages, upregulates free radical scavenging and improves endothelial function. Likewise, the sulfonamide drug sulfasalazine positively impacts the lipid profile by increasing HDL-C, and its use in RA has been correlated with reduced risk of myocardial infraction. In the biologic class, inhibitors of TNF-α and IL-6 contribute to improvements in endothelial function and promote anti-atherogenic properties of HDL-C, respectively. The immunosuppressant hydroxychloroquine positively affects insulin sensitization and the lipid profile. While no individual therapy has elicited optimal atheroprotection, further investigation of combination therapies are ongoing.

Soluble IL-6R-mediated IL-6 trans-signaling activation contributes to the pathological development of psoriasis

IL-6 has been suggested to function as an autocrine mitogen in the psoriatic epidermis. The biological activity of IL-6 relies on interactions with its receptors, including the membrane-bound IL-6 receptor (mIL-6R) and soluble IL-6 receptor (sIL-6R). Our study presents data showing that the levels of plasma IL-6 and sIL-6R were elevated in psoriatic patients. Genotyping of two single-nucleotide polymorphisms (SNPs) in IL-6R (rs4845617 and rs2228145) demonstrated that the SNP IL-6R (rs4845617) rather than IL-6R (rs2228145) shows a significant association with psoriasis (P = 0.006). To verify the functions of sIL-6R, cultured keratinocytes and imiquimod (IMQ)-induced psoriatic model mice were treated with sIL-6R. We found that the presence of sIL-6R in the HaCaT cell culture medium enhanced the IL-6-induced Stat3 activation, which resulted in abnormal keratinocyte proliferation and aberrant differentiation. Furthermore, the application of sIL-6R in vivo accelerated the pathological development of the disease. Our results demonstrate for the first time that genetic polymorphisms in the IL-6R gene are associated with psoriasis disease phenotypes in a Chinese psoriatic patient population; sIL-6R-mediated trans-signaling pathway plays a pivotal role in keratinocyte proliferation and differentiation, suggesting potential therapeutics for psoriasis. KEY MESSAGES: Patients with psoriasis displayed higher levels of IL-6 and sIL-6R compared with healthy controls. Analysis of genotypes revealed that IL-6R rs4845617 GG genotype associated with the risk of psoriasis. Supplement of sIL-6R further enhanced IL-6-induced Stat3 activation in keratinocytes. In vivo administration of sIL-6R accelerated, whereas sgp130FC alleviated, the pathological development of psoriasis.