Interleukin-1 blockade in rheumatoid arthritis and heart failure: a missed opportunity?

Immunoneuroendocrine, Stress, Metabolic, and Behavioural Responses in High-Fat Diet-Induced Obesity

Obesity has reached global epidemic proportions, and even though its effects are well-documented, studying the interactions among all influencing factors is crucial for a better understanding of its physiopathology. In a high-fat-diet-induced obesity animal model using C57BL/6J mice, behavioural responses were assessed through a battery of tests, while stress biomarkers and systemic inflammatory cytokines were measured using an Enzyme-Linked ImmunoSorbent Assay and a Bio-Plex Multiplex System. The peritoneal macrophage microbicide capacity was analysed via flow cytometry, and crown-like structures (CLSs) in white adipose tissue (WAT) were evaluated through staining techniques. Results indicated that obese mice exhibited increased body weight, hyperglycaemia, and hyperlipidaemia after 18 weeks on a high-fat diet, as well as worse physical conditions, poorer coordination and balance, and anxiety-like behaviour. Differences in corticosterone and noradrenaline concentrations were also found in obese animals, revealing a stress response and noradrenergic dysregulation, along with a weakened innate immune response characterized by a lower microbicide capacity, and the presence of an underlying inflammation evidenced by more CLSs in WAT. Altogether, these findings indicate that obesity deteriorates the entire stress, inflammatory, metabolic, sensorimotor and anxiety-like behavioural axis. This demonstrates that jointly evaluating all these aspects allows for a deeper and better exploration of this disease and its associated comorbidities, emphasizing the need for individualized and context-specific strategies for its management.

Glycogen synthase kinase-3β inhibition alleviates activation of the NLRP3 inflammasome in myocardial infarction

Inflammasome-promoted sterile inflammation following cardiac damage is critically implicated in heart dysfunction after myocardial infarction (MI). Glycogen synthase kinase-3 (GSK-3β) is a prominent mediator of the inflammatory response, and high GSK-3 activity is associated with various heart diseases. We investigated the regulatory mechanisms of GSK-3β in activation of the nod-like receptor family pyrin domain containing 3 (NLRP3) inflammasome in a rat model with successful induction of MI on days 2-28. An in vitro investigation was performed using newborn rat/human cardiomyocytes and fibroblast cultures under typical inflammasome stimulation and hypoxia treatment. GSK-3β inhibition markedly improved myocardial dysfunction and prevented remodeling, with parallel reduction in the parameters of NLRP3 inflammasome activation after MI. GSK-3β inhibition reduced NLRP3 inflammasome activation in cardiac fibroblasts, but not in cardiomyocytes. GSK-3β's interaction with activating signal cointegrator (ASC) as well as GSK-3β inhibition reduced ASC phosphorylation and oligomerization at the tissues and cellular levels. Taken together, these data show that GSK-3β directly mediates NLRP3 inflammasome activation, causing cardiac dysfunction in MI.

Chronic Heart Failure in Rheumatoid Arthritis Patients (Part III): Effects of Antirheumatic Drugs

Chronic autoimmune inflammation is one of the leading risk factors for the development of chronic heart failure (CHF) in rheumatoid arthritis (RA). The purpose of the review is to analyze the results of investigations on the effects of conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), biological disease-modifying anti-rheumatic drugs (bDMARDs), and targeted csDMARDs on cardiac function and the risk of developing CHF in patients with RA. Methotrexate may reduce the CHF risk and have a positive effect on the course of this condition in patients with RA. Despite the data on the presence of leflunomide effects that impede myocardial remodeling, there is no evidence of the role of the drug in the prevention of CHF in RA patients. Hydroxychloroquine may contribute to the prevention of CHF, but the risk of developing severe cardiotoxicity should be considered when taking the drug for a long time. Most studies have not revealed the negative effect of tumor necrosis factor inhibitors on the prevalence and incidence of new cases of CHF in RA patients, and an improvement in the structure and function of the heart during therapy has been shown. Inhibitors of interleukin (IL) -1, inhibitors of IL-6, inhibitors of T-cell co-stimulation, anti-B-cell therapy, targeted csDMARDs do not increase the risk of CHF and may have cardioprotective effects, including slowing the progression of left ventricle myocardial dysfunction. Due to the high risk of CHF and CHF-associated mortality in RA patients, early diagnosis of cardiac dysfunction, development of a prevention and treatment strategies are needed, including high-quality prospective studies to assess the effect of anti-rheumatic therapy on myocardial function, risk of developing and decompensation of CHF in RA patients. It is possible that some drugs may possess protective effects on cardiomyocytes so they could become the first-line drugs in patients with CHF or the risk of its development.

Interleukin-1 Beta-A Friend or Foe in Malignancies?

Interleukin-1 beta (IL-1β) is induced by inflammatory signals in a broad number of immune cell types. IL-1β (and IL-18) are the only cytokines which are processed by caspase-1 after inflammasome-mediated activation. This review aims to summarize current knowledge about parameters of regulation of IL-1β expression and its multi-facetted role in pathophysiological conditions. IL-1 signaling activates innate immune cells including antigen presenting cells, and drives polarization of CD4+ T cells towards T helper type (Th) 1 and Th17 cells. Therefore, IL-1β has been attributed a largely beneficial role in resolving acute inflammations, and by initiating adaptive anti-tumor responses. However, IL-1β generated in the course of chronic inflammation supports tumor development. Furthermore, IL-1β generated within the tumor microenvironment predominantly by tumor-infiltrating macrophages promotes tumor growth and metastasis via different mechanisms. These include the expression of IL-1 targets which promote neoangiogenesis and of soluble mediators in cancer-associated fibroblasts that evoke antiapoptotic signaling in tumor cells. Moreover, IL-1 promotes the propagation of myeloid-derived suppressor cells. Using genetic mouse models as well as agents for pharmacological inhibition of IL-1 signaling therapeutically applied for treatment of IL-1 associated autoimmune diseases indicate that IL-1β is a driver of tumor induction and development.

Treatment of Inflammatory Diseases with IL-1 Blockade

Background

Autoinflammatory diseases are distinct from autoimmune diseases. Whereas autoinflammatory diseases are due to dysfunctional T-cells and B-cells, autoinflammatory diseases are due to overproduction of macrophage cytokines particularly interleukin-1 beta (IL-1β). A causative role for IL-1 in autoinflammatory diseases is derived from clinical studies blocking the IL-1 receptor or neutralizing monoclonal antibodies or soluble receptors.

Methods

A review was performed of clinical trials in autoinflammatory diseases using the IL-1 receptor antagonist (anakinra), the soluble IL-1 receptor (rilonacept), antibodies to IL-1β (canakinumab, gevokizumab) and anti-IL-1α (xilonix).

Findings

Anakinra blocks the IL-1 Receptor type 1 (IL-1R1) and therefore blocks the activities of both IL-1α and IL-1β. Off-label use of anakinra is common for a broad spectrum of inflammatory diseases. Neutralization of IL-1β is used to treat hereditary autoinflammatory diseases but also atherosclerosis. Rilonacept reduces arterial wall inflammation in patients with chronic kidney disease. Neutralization of IL-1α has prolonged life in patients with advanced metastatic colorectal cancer. Compared to other cytokine blocking therapies, reducing the activities of IL-1 has an excellent safety record.

Conclusions

Blocking IL-1 therapies can be used to treat a wide-spectrum of acute and chronic inflammatory diseases.

A Review of Interleukin-1 in Heart Disease: Where Do We Stand Today?

Cardiovascular diseases are the leading cause of death worldwide. Research in the last two decades has emphasized the inflammatory process as a key component in the pathogenesis of many of them. The Interleukin-1 family is a pivotal element of inflammation and has been well studied as a therapeutic target in various inflammatory states. Recent trials have explored the effect of Interleukin-1 blockade in cardiovascular diseases and initial evidence of the relevance of such treatment in this field of medicine accumulate. This review will describe the role of Interleukin-1 in heart diseases and the potential therapeutic effect of its blockade in such diseases.

Suppression of innate inflammation and immunity by interleukin-37

IL-37 is unique in the IL-1 family in that unlike other members of the family, IL-37 broadly suppresses innate immunity. IL-37 can be elevated in humans with inflammatory and autoimmune diseases where it likely functions to limit inflammation. Transgenic mice expressing human IL-37 (IL37-tg) exhibit less severe inflammation in models of endotoxin shock, colitis, myocardial infarction, lung, and spinal cord injury. IL37-tg mice have reduced antigen-specific responses and dendritic cells (DCs) from these mice exhibit characteristics of tolerogenic DCs. Compared to aging wild-type (WT) mice, aging IL37-tg mice are protected against B-cell leukemogenesis and heart failure. Treatment of WT mice with recombinant human IL-37 has been shown to be protective in several models of inflammation and injury. IL-37 binds to the IL-18 receptor but then recruits the orphan IL-1R8 (formerly TIR8 or SIGIRR) in order to function as an inhibitor. Here, we review the discovery of IL-37, its production, release, and mechanisms by which IL-37 reduces inflammation and suppresses immune responses. The data reviewed here suggest a therapeutic potential for IL-37.

IL-37 Causes Excessive Inflammation and Tissue Damage in Murine Pneumococcal Pneumonia

Streptococcus pneumoniae infections can lead to severe complications with excessive immune activation and tissue damage. Interleukin-37 (IL-37) has gained importance as a suppressor of innate and acquired immunity, and its effects have been therapeutic as they prevent tissue damage in autoimmune and inflammatory diseases. By using RAW macrophages, stably transfected with human IL-37, we showed a 70% decrease in the cytokine levels of IL-6, TNF-α, and IL-1β, and a 2.2-fold reduction of the intracellular killing capacity of internalized pneumococci in response to pneumococcal infection. In a murine model of infection with S. pneumoniae, using mice transgenic for human IL-37b (IL-37tg), we observed an initial decrease in cytokine expression of IL-6, TNF-α, and IL-1β in the lungs, followed by a late-phase enhancement of pneumococcal burden and subsequent increase of proinflammatory cytokine levels. Additionally, a marked increase in recruitment of alveolar macrophages and neutrophils was noted, while TRAIL mRNA was reduced 3-fold in lungs of IL-37tg mice, resulting in necrotizing pneumonia with augmented death of infiltrating neutrophils, enhanced bacteremic spread, and increased mortality. In conclusion, we have identified that IL-37 modulates several core components of a successful inflammatory response to pneumococcal pneumonia, which lead to increased inflammation, tissue damage, and mortality.

Anti-inflammatory panacea? The expanding therapeutics of interleukin-1 blockade

PURPOSE OF REVIEW

Blockade of interleukin (IL)-1 signaling is one of the oldest biologic therapies, yet the use of these agents is on the rise as the role of IL-1 activation is being recognized in a wide spectrum of inflammatory disorders. This review will cover established and emerging uses of IL-1 antagonism in rheumatic diseases.

RECENT FINDINGS

Expanding off-label indications for IL-1 blockade include neutrophil-dominant skin diseases, including pyoderma gangrenosum, hidradenitis supperativa, and pustular psoriasis. There is also increasing evidence for the use of IL-1 blockade in heart failure associated with rheumatic diseases. Somatic mosaicism in NLRP3 may explain the onset of later-in-life presentations of periodic fevers which are responsive to IL-1 blockade. Of importance, clinical response to anti-IL-1 therapy does not always denote protection from autoinflammatory disease complications such as macrophage activation syndrome or amyloidosis.

SUMMARY

Indications for IL-1 blocking therapies will likely continue to broaden, but given the rarity of many rheumatic diseases which respond to such treatment, rigorous, large clinical trials for each indication are unlikely to occur. Thus, recommended use of these medications will often fall to the discretion of the astute physician. However, medication cost and hurdles of insurance approval, rather than drug efficacy, may be the primary limitation for more widespread use.

An expanding role for interleukin-1 blockade from gout to cancer

There is an expanding role for interleukin (IL)-1 in diseases from gout to cancer. More than any other cytokine family, the IL-1 family is closely linked to innate inflammatory and immune responses. This linkage is because the cytoplasmic segment of all members of the IL-1 family of receptors contains a domain, which is highly homologous to the cytoplasmic domains of all toll-like receptors (TLRs). This domain, termed "toll IL-1 receptor (TIR) domain," signals as does the IL-1 receptors; therefore, inflammation due to the TLR and the IL-1 families is nearly the same. Fundamental responses such as the induction of cyclo-oxygenase type 2, increased surface expression of cellular adhesion molecules and increased gene expression of a broad number of inflammatory molecules characterizes IL-1 signal transduction as it does for TLR agonists. IL-1β is the most studied member of the IL-1 family because of its role in mediating autoinflammatory disease. However, a role for IL-1α in disease is being validated because of the availability of a neutralizing monoclonal antibody to human IL-1α. There are presently three approved therapies for blocking IL-1 activity. Anakinra is a recombinant form of the naturally occurring IL-1 receptor antagonist, which binds to the IL-1 receptor and prevents the binding of IL-1β as well as IL-1α. Rilonacept is a soluble decoy receptor that neutralizes primarily IL-1β but also IL-1α. Canakinumab is a human monoclonal antibody that neutralizes only IL-1β. Thus, a causal or significant contributing role can be established for IL-1β and IL-1α in human disease.

Preventing Heart Failure in Inflammatory and Immune Disorders

Patients with chronic inflammatory diseases are at increased risk for heart failure due to ischemic heart disease and other causes including heart failure with preserved ejection fraction. Using rheumatoid arthritis and treated HIV infection as two prototypical examples, we review the epidemiology and potential therapies to prevent heart failure in these populations. Particular focus is given to anti-inflammatory therapies including statins and biologic disease modifying drugs. There is also limited evidence for lifestyle changes and blockade of the renin-angiotensin-aldosterone system. We conclude by proposing how a strategy for heart failure prevention, such as the model tested in the Screening To Prevent Heart Failure (STOP-HF) trial, may be adapted to chronic inflammatory disease.