Selective Interleukin-6 Trans-Signaling Blockade Is More Effective Than Panantagonism in Reperfused Myocardial Infarction

Intratumoral Delivery of Genetically Engineered Anti-IL-6 Trans-signaling Therapeutics

Interleukin-6 (IL-6) is a highly pro-inflammatory cytokine involved in the etiopathology of several inflammatory diseases and cancer. As so, the inhibition of IL-6 signaling pathways has emerged as an attractive therapeutic avenue for the treatment of several chronic diseases. Since IL-6 trans-signaling was described as the pathological branch of IL-6, selective inhibitors were developed. Next-generation variants with increased trans-signaling specificity and potency emerged as great candidates for the treatment of several diseases, with reduced off-target effects. The highly time-consuming and costly processes involving recombinant protein production, however, have hampered the progress of anti-cytokine pharmaceuticals in clinic so far. Herein, we developed gene therapeutic modalities of IL-6-trans-signaling inhibitors as alternatives for sustained recombinant protein secretion. By using an IL-6-dependent lymphoma cell line and xenograft tumor model, we demonstrated the superior inhibitory potential of second-generation anti-IL-6 trans-signaling therapeutic. We compared the efficiency of distinct gene delivery modalities using a bioluminescent biomarker probe and observed consistent protein production via cell-based delivery. When delivered intratumorally, genetically engineered sgp130FlyRFc-secreting cells significantly reduced tumor burden and increased animal survival, representing a promising therapeutic avenue to be explored in clinically relevant gene delivery applications.

Loss of peptidylarginine deiminase 4 mitigates maladaptive cardiac remodeling after myocardial infarction through inhibition of inflammatory and profibrotic pathways

Inflammation and progressive fibrosis represent predictive risk factors for heart failure (HF) development following myocardial infarction (MI). Peptidylargininine deiminase 4 (PAD4) catalyzes the citrullination of arginine residues in polypeptides and has recently been identified as a contributor to HF pathogenesis. This study aimed to evaluate the role of PAD4 in monocytes / macrophages (Mo/Mφ) and cardiac fibroblasts (CFs) for cardiac repair following MI and HF progression. Cardiac Padi4 expression significantly increased in mice subjected to MI by permanent coronary artery ligation as well as in humans who died from MI. Transcriptome analysis revealed marked downregulation of inflammation-related genes in infarcted hearts and cardiac Mo/Mφ from global PAD4 knockout (PAD4-/-) mice on day 7 post-MI accompanied by increased frequency of reparative CD206+ macrophages. Mechanistically, pharmacological and genetic PAD4 inhibition abrogated nuclear NF-κB translocation and inflammatory gene expression in bone marrow-derived macrophages (BMDM). Simultaneously, reduced inflammation and diminished cardiac levels of transforming growth factor-β (TGF-β) along with impaired IL-6 / TGF-β signaling in PAD4-/- CFs were associated with decreased expression of fibrotic genes, reduced collagen deposition, improved cardiac function, and enhanced 28-day survival in PAD4-/- mice. Strikingly, whereas pharmacological PAD inhibition in the acute phase after MI exacerbated cardiac damage, treatment starting on day 7 ameliorated cardiac remodeling and improved long-term survival in mice. Collectively, we here identified PAD4 as a critical regulator of inflammatory genes in Mo/Mφ and of profibrotic pathways in CFs. Thus, therapeutic approaches directed against PAD4 are promising interventions to alleviate adverse cardiac remodeling and subsequent HF development.

Interleukin-6: Molecular Mechanisms and Therapeutic Perspectives in Atrial Fibrillation

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia with a multifactorial pathophysiology involving electrical, structural, and autonomic remodeling of the atria. AF is closely associated with elevated interleukin-6 (IL-6) levels, which contribute to atrial remodeling and the progression of AF. This review summarizes the mechanisms by which IL-6 promotes AF through inflammatory pathways, atrial fibrosis, electrical remodeling, and calcium mishandling. Experimental models have demonstrated that IL-6 neutralization reduces the incidence of AF, highlighting its potential as a therapeutic target. Future studies should focus on IL-6 blockade strategies to manage AF, aiming to improve patient outcomes.

The roles of neutrophils in cardiovascular diseases

The immune response plays a vital role in the development of cardiovascular diseases (CVDs). As a crucial component of the innate immune system, neutrophils are involved in the initial inflammatory response following cardiovascular injury, thereby inducing subsequent damage and promoting recovery. Neutrophils exert their functional effects in tissues through various mechanisms, including activation and the formation of neutrophil extracellular traps (NETs). Once activated, neutrophils are recruited to the site of injury, where they release inflammatory mediators and cytokines. This study discusses the main mechanisms associated with neutrophil activity and proposes potential new therapeutic targets. In this review, we systematically summarize the diverse phenotypes of neutrophils in disease regulatory mechanisms, different modes of cell death, and focus on the relevance of neutrophils to various CVDs, including atherosclerosis, acute coronary syndrome, myocardial ischemia/reperfusion injury, hypertension, atrial fibrillation, heart failure, and viral myocarditis. Finally, we also emphasize the preclinical/clinical translational significance of neutrophil-targeted strategies.

No evidence for paradoxical effects of tocilizumab in rodents

Interleukin-6 (IL-6) is a multifunctional cytokine with important functions in health and disease. In order to activate its target cells, IL-6 binds first to the IL-6 receptor (IL-6R), which in turn induces the recruitment and homodimerization of the signal-transducing β-receptor gp130 and the activation of intracellular signaling cascades, including the phosphoinositide 3-kinase (PI3K)-AKT cascade. IL-6 is involved in the pathogenesis of multiple inflammatory diseases, and tocilizumab, a monoclonal antibody that binds to the IL-6R and thus blocks the biological activities of IL-6, is in clinical use worldwide for the treatment of patients with inflammatory diseases, including rheumatoid arthritis. Recently, Weng and colleagues published a paper in Naunyn-Schmiedeberg's Archives of Pharmacology describing paradoxical effects of tocilizumab when used on murine cells in vitro and in a rat model of acute lung injury in vivo. In this communication, I provide evidence that the results presented by Weng and colleagues are not compatible with what is known about the biology of IL-6 and highlight why the provided evidence is insufficient to believe that tocilizumab shows the reported paradoxical effects in rodents.

Glycoprotein 130 Antagonism Counteracts Metabolic and Inflammatory Alterations to Enhance Right Ventricle Function in Pulmonary Artery Banded Pigs

Background

Right ventricular dysfunction (RVD) is a risk factor for death in multiple cardiovascular diseases, but RV-enhancing therapies are lacking. Inhibition of glycoprotein-130 (GP130) signaling with the small molecule SC144 improves RV function in rodent RVD via anti-inflammatory and metabolic mechanisms. However, SC144's efficacy and molecular effects in a translational large animal model of RVD are unknown.

Methods

4-week-old castrated male pigs underwent pulmonary artery banding (PAB). After 3 weeks, PAB pigs were randomized into 2 groups (daily injections of SC144 [2.2 mg/kg, PAB-SC144, n=5] or vehicle [PAB-Veh, n=5] for 3 weeks). Five age-matched pigs served as controls. Cardiac MRI quantified RV size/function. Right heart catheterization evaluated hemodynamics. Single-nucleus RNA sequencing delineated cell-type specific changes between experimental groups. Electron microscopy evaluated RV mitochondrial morphology. Phosphoproteomics identified dysregulated RV kinases. Lipidomics and metabolomics quantified lipid species and metabolites in RV tissue. Quantitative proteomics examined RV mitochondrial protein regulation.

Results

SC144 significantly improved RV ejection fraction (Control: 60±4%, PAB-Veh: 22±10%, PAB-SC144: 37±6%) despite similar RV afterload. Single-nucleus RNA sequencing demonstrated PAB-Veh pigs had lower cardiomyocyte and higher macrophage/lymphocyte/pericyte/endothelial cell abundances as compared to control, and many of these changes were blunted by SC144. SC144 combatted the downregulation of cardiomyocyte metabolic genes induced by PAB. Kinome enrichment analysis suggested SC144 counteracted RV mTORC1 activation. Correspondingly, SC144 rebalanced RV autophagy pathway proteins and improved mitochondrial morphology. Integrated lipidomics, metabolomics, and proteomics analyses revealed SC144 restored fatty acid metabolism. Finally, CellChat analysis revealed SC144 restored pericyte-endothelial cell cross-talk.

Conclusion

GP130 antagonism blunts elevated immune cell abundance, reduces pro-inflammatory gene transcription in macrophages and lymphocytes, rebalances autophagy and preserves fatty acid metabolism in cardiomyocytes, and restores endothelial cell and pericyte communication to improve RV function.

First time ACS in patients with on-target lipid levels: Inflammation at admission and re-event rate at follow-up

BACKGROUND

Dyslipidaemia, inflammation and elevated Lp(a) levels are associated with the progression of atherosclerosis. This study investigates whether patients with a first-time presentation of chest pain and on-target LDL-C levels and intermediate FRS/ESC-Score risks, display a high inflammatory burden linked to myocardial injury and whether inflammation at admission affects the re-event rate up to 6 years follow-up.

METHODS

Blind assessments of novel inflammatory markers such as Glycoprotein A and B via nuclear magnetic resonance (NMR), cytokines, hsCRP, Neutrophil-to-Lymphocyte ratio (NLR) and Lipoprotein(a) levels were examined. Out of 198 chest pain patients screened, 97 met the inclusion criteria at admission.

RESULTS

cTnI(+) patients (>61 ng/L) with elevated Lipoprotein(a), showed significantly increased levels of Glycoprotein A and B, hsCRP, IL-6, a high NLR and a reduced left ventricular ejection fraction (%) compared to cTnI(-) individuals. Those patients, with a higher inflammatory burden at hospital admission (hsCRP, IL-6, Glycoprotein A and B, and Lipoprotein(a)) had a higher re-event rate at follow-up.

CONCLUSIONS

Inflammation and Lipoprotein(a) levels were particularly prominent in patients presenting with reduced left ventricular ejection fraction. Notably, Glycoproteins A/B emerge as novel markers of inflammation in these patients. Our study highlights the significantly higher impact of inflammatory burden in patients with chest pain and high level of myocardial damage than in those with lower myocardial affectation, even when they all had lipid levels well controlled. Inflammation at the time of admission influenced the re-event rate over a follow-up period of up to 6 years.

Ironing Out the Mechanism of gp130 Signaling

gp130 functions as a shared signal-transducing subunit not only for interleukin (IL)-6 but also for eight other human cytokine receptor complexes. The IL-6 signaling pathway mediated through gp130 encompasses classical, trans, or cluster signaling, intricately regulated by a diverse array of modulators affecting IL-6, its receptor, and gp130. Currently, only a limited number of small molecule antagonists and agonists for gp130 are known. This review aims to comprehensively examine the current knowledge of these modulators and provide insights into their pharmacological properties, particularly in the context of cancer and other diseases. Notably, the prominent gp130 modulators SC144, bazedoxifene, and raloxifene are discussed in detail, with a specific focus on the discovery of SC144's iron-chelating properties. This adds a new dimension to the understanding of its pharmacological effects and therapeutic potential in conditions where iron homeostasis is significant. Our bioinformatic analysis of gp130 and genes related to iron homeostasis reveals insightful correlations, implicating the role of iron in the gp130 signaling pathway. Overall, this review contributes to the evolving understanding of gp130 modulation and its potential therapeutic applications in various disease contexts. SIGNIFICANCE STATEMENT: This perspective provides a timely and comprehensive analysis of advancements in gp130 signaling research, emphasizing the therapeutic implications of the currently available modulators. Bioinformatic analysis demonstrates potential interplay between gp130 and genes that regulate iron homeostasis, suggesting new therapeutic avenues. By combining original research findings with a broader discussion of gp130's therapeutic potential, this perspective significantly contributes to the field.

Heart failure with preserved ejection fraction: The role of inflammation

Heart failure (HF) is a debilitating clinical syndrome affecting 64.3 million patients worldwide. More than 50% of HF cases are attributed to HF with preserved ejection fraction (HFpEF), an entity growing in prevalence and mortality. Although recent breakthroughs reveal the prognostic benefits of sodium-glucose co-transporter 2 inhibitors (SGLT2i) in HFpEF, there is still a lack of effective pharmacological therapy available. This highlights a major gap in medical knowledge that must be addressed. Current evidence attributes HFpEF pathogenesis to an interplay between cardiometabolic comorbidities, inflammation, and renin-angiotensin-aldosterone-system (RAAS) activation, leading to cardiac remodelling and diastolic dysfunction. However, conventional RAAS blockade has demonstrated limited benefits in HFpEF, which emphasises that alternative therapeutic targets should be explored. Presently, there is limited literature examining the use of anti-inflammatory HFpEF therapies despite growing evidence supporting its importance in disease progression. Hence, this review aims to explore current perspectives on HFpEF pathogenesis, including the importance of inflammation-driven cardiac remodelling and the therapeutic potential of anti-inflammatory therapies.

Obesity Arrhythmias: Role of IL-6 Trans-Signaling

Obesity is a chronic disease that is rapidly increasing in prevalence and affects more than 600 million adults worldwide, and this figure is estimated to increase by at least double by 2030. In the United States, more than one-third of the adult population is either overweight or obese. The global obesity epidemic is a major risk factor for the development of life-threatening arrhythmias occurring in patients with long QT, particularly in conditions where multiple heart-rate-corrected QT-interval-prolonging mechanisms are simultaneously present. In obesity, excess dietary fat in adipose tissue stimulates the release of immunomodulatory cytokines such as interleukin (IL)-6, leading to a state of chronic inflammation in patients. Over the last decade, increasing evidence has been found to support IL-6 signaling as a powerful predictor of the severity of heart diseases and increased risk for ventricular arrhythmias. IL-6's pro-inflammatory effects are mediated via trans-signaling and may represent a novel arrhythmogenic risk factor in obese hearts. The first selective inhibitor of IL-6 trans-signaling, olamkicept, has shown encouraging results in phase II clinical studies for inflammatory bowel disease. Nevertheless, the connection between IL-6 trans-signaling and obesity-linked ventricular arrhythmias remains unexplored. Therefore, understanding how IL-6 trans-signaling elicits a cellular pro-arrhythmic phenotype and its use as an anti-arrhythmic target in a model of obesity remain unmet clinical needs.

The double-edged effects of IL-6 in liver regeneration, aging, inflammation, and diseases

Interleukin-6 (IL-6) is a pleiotropic cytokine and exerts its complex biological functions mainly through three different signal modes, called cis-, trans-, and cluster signaling. When IL-6 binds to its membrane or soluble receptors, the co-receptor gp130 is activated to initiate downstream signaling and induce the expression of target genes. In the liver, IL-6 can perform its anti-inflammatory activities to promote hepatocyte reprogramming and liver regeneration. On the contrary, IL-6 also exerts the pro-inflammatory functions to induce liver aging, fibrosis, steatosis, and carcinogenesis. However, understanding the roles and underlying mechanisms of IL-6 in liver physiological and pathological processes is still an ongoing process. So far, therapeutic agents against IL‑6, IL‑6 receptor (IL‑6R), IL-6-sIL-6R complex, or IL-6 downstream signal transducers have been developed, and determined to be effective in the intervention of inflammatory diseases and cancers. In this review, we summarized and highlighted the understanding of the double-edged effects of IL-6 in liver homeostasis, aging, inflammation, and chronic diseases, for better shifting the "negative" functions of IL-6 to the "beneficial" actions, and further discussed the potential therapeutic effects of targeting IL-6 signaling in the clinics.

Repair of the Infarcted Heart: Cellular Effectors, Molecular Mechanisms and Therapeutic Opportunities

The adult mammalian heart has limited endogenous regenerative capacity and heals through the activation of inflammatory and fibrogenic cascades that ultimately result in the formation of a scar. After infarction, massive cardiomyocyte death releases a broad range of damage-associated molecular patterns that initiate both myocardial and systemic inflammatory responses. TLRs (toll-like receptors) and NLRs (NOD-like receptors) recognize damage-associated molecular patterns (DAMPs) and transduce downstream proinflammatory signals, leading to upregulation of cytokines (such as interleukin-1, TNF-α [tumor necrosis factor-α], and interleukin-6) and chemokines (such as CCL2 [CC chemokine ligand 2]) and recruitment of neutrophils, monocytes, and lymphocytes. Expansion and diversification of cardiac macrophages in the infarcted heart play a major role in the clearance of the infarct from dead cells and the subsequent stimulation of reparative pathways. Efferocytosis triggers the induction and release of anti-inflammatory mediators that restrain the inflammatory reaction and set the stage for the activation of reparative fibroblasts and vascular cells. Growth factor-mediated pathways, neurohumoral cascades, and matricellular proteins deposited in the provisional matrix stimulate fibroblast activation and proliferation and myofibroblast conversion. Deposition of a well-organized collagen-based extracellular matrix network protects the heart from catastrophic rupture and attenuates ventricular dilation. Scar maturation requires stimulation of endogenous signals that inhibit fibroblast activity and prevent excessive fibrosis. Moreover, in the mature scar, infarct neovessels acquire a mural cell coat that contributes to the stabilization of the microvascular network. Excessive, prolonged, or dysregulated inflammatory or fibrogenic cascades accentuate adverse remodeling and dysfunction. Moreover, inflammatory leukocytes and fibroblasts can contribute to arrhythmogenesis. Inflammatory and fibrogenic pathways may be promising therapeutic targets to attenuate heart failure progression and inhibit arrhythmia generation in patients surviving myocardial infarction.

Piezo1-Mediated Neurogenic Inflammatory Cascade Exacerbates Ventricular Remodeling After Myocardial Infarction

BACKGROUND

Heart failure is associated with a high rate of mortality and morbidity, and ventricular remodeling invariably precedes heart failure. Ventricular remodeling is fundamentally driven by mechanotransduction that is regulated by both the nervous system and the immune system. However, it remains unknown which key molecular factors govern the neuro/immune/cardio axis that underlies mechanotransduction during ventricular remodeling. Here, we investigated whether the mechanosensitive Piezo cation channel-mediated neurogenic inflammatory cascade underlies ventricular remodeling-related mechanotransduction.

METHODS

By ligating the left coronary artery of rats to establish an in vivo model of chronic myocardial infarction (MI), lentivirus-mediated thoracic dorsal root ganglion (TDRG)-specific Piezo1 knockdown rats and adeno-associated virus-PHP.S-mediated TDRG neuron-specific Piezo1 knockout mice were used to investigate whether Piezo1 in the TDRG plays a functional role during ventricular remodeling. Subsequently, neutralizing antibody-mediated TDRG IL-6 (interleukin-6) inhibition rats and adeno-associated virus-PHP.S-mediated TDRG neuron-specific IL-6 knockdown mice were used to determine the mechanism underlying neurogenic inflammation. Primary TDRG neurons were used to evaluate Piezo1 function in vitro.

RESULTS

Expression of Piezo1 and IL-6 was increased, and these factors were functionally activated in TDRG neurons at 4 weeks after MI. Both knockdown of TDRG-specific Piezo1 and deletion of TDRG neuron-specific Piezo1 lessened the severity of ventricular remodeling at 4 weeks after MI and decreased the level of IL-6 in the TDRG or heart. Furthermore, inhibition of TDRG IL-6 or knockdown of TDRG neuron-specific IL-6 also ameliorated ventricular remodeling and suppressed the IL-6 cascade in the heart, whereas the Piezo1 level in the TDRG was not affected. In addition, enhanced Piezo1 function, as reflected by abundant calcium influx induced by Yoda1 (a selective agonist of Piezo1), led to increased release of IL-6 from TDRG neurons in mice 4 weeks after MI.

CONCLUSIONS

Our findings point to a critical role for Piezo1 in ventricular remodeling at 4 weeks after MI and reveal a neurogenic inflammatory cascade as a previously unknown facet of the neuronal immune signaling axis underlying mechanotransduction.

Construction of preclinical evidence for propofol in the treatment of reperfusion injury after acute myocardial infarction: A systematic review and meta-analysis

Propofol, a commonly used intravenous anesthetic, has demonstrated potential in protecting against myocardial ischemia/reperfusion injury (MIRI) based on preclinical animal studies. However, the clinical benefits of propofol in this context are subject to debate. We conducted a systematic search across eight databases to identify all relevant animal studies investigating the preventive effects of propofol on MIRI until October 30, 2023. We assessed the methodological quality of the included studies using SYRCLE's bias risk tool. Statistical analysis was performed using STATA 15.1. The primary outcome measures analyzed in this study were myocardial infarct size (IS) and myocardial injury biomarkers. This study presents a comprehensive analysis of 48 relevant animal studies investigating propofol's preventive effects on MIRI. Propofol administration demonstrated a reduction in myocardial IS and decreased levels of myocardial injury biomarkers (CK-MB, LDH, cTnI). Moreover, propofol improved myocardial function parameters (+dp/dtmax, -dP/dtmax, LVEF, LVFS), exhibited favorable effects on inflammatory markers (IL-6, TNF-α) and oxidative stress markers (SOD, MDA), and reduced myocardial cell apoptotic index (AI). These findings suggest propofol exerts cardioprotective effects by reducing myocardial injury, decreasing infarct size, and improving heart function. However, the absence of animal models that accurately represent comorbidities such as aging and hypertension, as well as inconsistent administration methods that align with clinical practice, may hinder its clinical translation. Further robust investigations are required to validate these findings, elucidate the underlying mechanisms of propofol, and facilitate its potential translation into clinical practice.

Interleukin 6 Signalling in Heart Failure With Preserved and Reduced Ejection Fraction

AIM

Identification of interleukin-6 (IL-6) signaling pathways in patients with chronic heart failure (CHF).

MATERIAL AND METHODS

The diversity of IL-6 effects is due to the presence of classical signaling and trans-signaling pathways. The study included 164 patients with CHF hospitalized for acute decompensated heart failure (ADHF), of which 129 had reduced left ventricular ejection fraction (HFrEF), and 35 had preserved ejection fraction (HFpEF). Blood concentrations of IL-6, soluble IL-6 receptor (sIL-6R), soluble transducer protein gp130 (sgp130), and high-sensitivity C-reactive protein (hsCRP) were measured.

RESULTS

Patients with HFpEF had lower concentrations of IL-6 (6.15 [2.78, 10.65] pg/ml) and hsCRP (11.27 [5.84, 24.40] mg/ml) than patients with HFrEF (9.20 [4.70; 15.62] pg/ml and 17.23 [8.70; 34.51 mg/ml], respectively). In contrast, concentrations of rIL-6R were higher in HFpEF (59.06 [40.00; 75.85] ng/ml) than in HFrEF (49.15 [38.20; 64.89] ng/ml). Concentrations of sgp130 were not significantly different. In patients with HFrEF, positive correlations were found between the concentrations of IL-6 and hsCRP, IL-6 and rIL-6R, and IL-6 and sgp130, while in patients with HFpEF, there was a correlation only between IL-6 and hsCRP, which appeared stronger than in patients with HFrEF (r=0.698; p<0.001 and r=0.297; p<0.05, respectively).

CONCLUSION

Classical IL-6 signaling and trans-signaling are expressed to different degrees in patients with HFrEF and HFpEF in ADHF. The results of the study supplement the existing knowledge about the pathogenesis of inflammation in CHF and may contribute to the development of new methods and approaches to the treatment of the disease.

Nonspecific Inhibition of IL6 Family Cytokine Signalling by Soluble gp130

IL6 is a proinflammatory cytokine that binds to membrane-bound IL6 receptor (IL6R) or soluble IL6R to signal via gp130 in cis or trans, respectively. We tested the hypothesis that sgp130Fc, which is believed to be a selective IL6 trans-signalling inhibitor, is in fact a non-specific inhibitor of gp130 signalling. In human cancer and primary cells, sgp130Fc inhibited IL6, IL11, OSM and CT1 cis-signalling. The IC50 values of sgp130Fc for IL6 and OSM cis-signalling were markedly (20- to 200-fold) lower than the concentrations of sgp130Fc used in mouse studies and clinical trials. sgp130 inhibited IL6 and OSM signalling in the presence of an ADAM10/17 inhibitor and the absence of soluble IL6R or OSMR, with effects that were indistinguishable from those of a gp130 neutralising antibody. These data show that sgp130Fc does not exclusively block IL6 trans-signalling and reveal instead that broad inhibition of gp130 signalling likely underlies its therapeutic effects. This proposes global or modular inhibition of gp130 as a therapeutic approach for treating human disease.

Selective blockade of interleukin 6 trans-signaling depresses atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) has been accepted as an inflammatory atrial myopathy. Interleukin 6 (IL-6)-dependent inflammatory signaling pathways take context-dependent effects on cardiovascular diseases. IL-6 trans-signaling is predominantly pro-inflammatory. However, its effect on AF is unclear.

OBJECTIVE

The purpose of this study was to investigate the role of IL-6 trans-signaling in AF.

METHODS

Circulating levels of IL-6, soluble IL-6 receptor, and soluble glycoprotein 130 (sgp130) in patients with AF and controls were measured to estimate the activation of IL-6 trans-signaling. A mouse model of AF was established by transverse aortic constriction surgery. Sgp130Fc administration was used for the selective blockade of IL-6 trans-signaling. Studies were conducted to evaluate the effects and underlying mechanisms of sgp130Fc on AF inducibility and atrial conduction abnormalities and structural remodeling.

RESULTS

In patients, the elevation of IL-6 trans-signaling level was positively associated with AF occurrence. IL-6 trans-signaling activation was recapitulated in the mouse model of AF. In transverse aortic constriction-challenged mice, the selective blockade of IL-6 trans-signaling with sgp130Fc attenuated AF inducibility, which was attributable to the amelioration of slow conduction and conduction heterogeneity induced by atrial dilation, fibrosis, and reduction in connexin 40 and redistribution of connexin 43. Sgp130Fc administration also reduced immune cell infiltration and oxidative stress in the mouse atrium and abrogated IL-6 trans-signaling activation-mediated connexin dysregulation and reactive oxygen species production in atrial myocytes.

CONCLUSION

IL-6 trans-signaling activation contributes to AF development, and its selective blockade may promise a novel therapeutic strategy.

Bispecific soluble cytokine receptor-nanobody fusions inhibit Interleukin (IL-)6 trans-signaling and IL-12/23 or tumor necrosis factor (TNF) signaling

At least 0.5% of people in the Western world develop inflammatory bowel disease (IBD). While antibodies that block tumor necrosis factor (TNF) α and Interleukin (IL-)23 have been approved for the treatment of IBD, IL-6 antibodies failed in the phase II clinical trial due to non-tolerable side effects. However, two clinical phase II studies suggest that inhibiting IL-6/soluble IL-6R (sIL-6R)-induced trans-signaling via the cytokine receptor gp130 benefit IBD patients with fewer adverse events. Here we develop inhibitors targeting a combination of IL-6/sIL-6R and TNF or IL-12/IL-23 signaling, named cs130-TNFVHHFc and cs130-IL-12/23VHHFc. Surface plasmon resonance experiments showed that recombinant cs130-TNFVHHFc and cs130-IL-12/23VHHFc bind with high affinity to IL-6/sIL-6R complexes and human TNFα (hTNFα) or IL-12/IL-23, respectively. Immunoprecipitation experiments have verified the higher ordered complex formation of the inhibitors with IL-6/sIL-6R and IL-12. We demonstrated that cs130-TNFVHHFc and cs130-IL-12/23VHHFc block IL-6/sIL-6R trans-signaling-induced proliferation and STAT3 phosphorylation of Ba/F3-gp130 cells, as well as hTNFα- or IL-23-induced signaling, respectively. In conclusion, cs130-TNFVHHFc and cs130-IL-12/23VHHFc represent a class of dimeric and bispecific chimeric cytokine inhibitors that consist of a soluble cytokine receptor fused to anti-cytokine nanobodies.

Inflammation in Myocardial Ischemia/Reperfusion Injury: Underlying Mechanisms and Therapeutic Potential

Acute myocardial infarction (MI) occurs when blood flow to the myocardium is restricted, leading to cardiac damage and massive loss of viable cardiomyocytes. Timely restoration of coronary flow is considered the gold standard treatment for MI patients and limits infarct size; however, this intervention, known as reperfusion, initiates a complex pathological process that somewhat paradoxically also contributes to cardiac injury. Despite being a sterile environment, ischemia/reperfusion (I/R) injury triggers inflammation, which contributes to infarct expansion and subsequent cardiac remodeling and wound healing. The immune response is comprised of subsets of both myeloid and lymphoid-derived cells that act in concert to modulate the pathogenesis and resolution of I/R injury. Multiple mechanisms, including altered metabolic status, regulate immune cell activation and function in the setting of acute MI, yet our understanding remains incomplete. While numerous studies demonstrated cardiac benefit following strategies that target inflammation in preclinical models, therapeutic attempts to mitigate I/R injury in patients were less successful. Therefore, further investigation leveraging emerging technologies is needed to better characterize this intricate inflammatory response and elucidate its influence on cardiac injury and the progression to heart failure.

Targeting IL-6 trans-signalling: past, present and future prospects

Interleukin-6 (IL-6) is a key immunomodulatory cytokine that affects the pathogenesis of diverse diseases, including autoimmune diseases, chronic inflammatory conditions and cancer. Classical IL-6 signalling involves the binding of IL-6 to the membrane-bound IL-6 receptor α-subunit (hereafter termed 'mIL-6R') and glycoprotein 130 (gp130) signal-transducing subunit. By contrast, in IL-6 trans-signalling, complexes of IL-6 and the soluble form of IL-6 receptor (sIL-6R) signal via membrane-bound gp130. A third mode of IL-6 signalling - known as cluster signalling - involves preformed complexes of membrane-bound IL-6-mIL-6R on one cell activating gp130 subunits on target cells. Antibodies and small molecules have been developed that block all three forms of IL-6 signalling, but in the past decade, IL-6 trans-signalling has emerged as the predominant pathway by which IL-6 promotes disease pathogenesis. The first selective inhibitor of IL-6 trans-signalling, sgp130, has shown therapeutic potential in various preclinical models of disease and olamkicept, a sgp130Fc variant, had promising results in phase II clinical studies for inflammatory bowel disease. Technological developments have already led to next-generation sgp130 variants with increased affinity and selectivity towards IL-6 trans-signalling, along with indirect strategies to block IL-6 trans-signalling. Here, we summarize our current understanding of the biological outcomes of IL-6-mediated signalling and the potential for targeting this pathway in the clinic.

Therapeutic potential of IL6R blockade for the treatment of sepsis and sepsis-related death: A Mendelian randomisation study

BACKGROUND

Sepsis is characterised by dysregulated, life-threatening immune responses, which are thought to be driven by cytokines such as interleukin 6 (IL-6). Genetic variants in IL6R known to down-regulate IL-6 signalling are associated with improved Coronavirus Disease 2019 (COVID-19) outcomes, a finding later confirmed in randomised trials of IL-6 receptor antagonists (IL6RAs). We hypothesised that blockade of IL6R could also improve outcomes in sepsis.

METHODS AND FINDINGS

We performed a Mendelian randomisation (MR) analysis using single nucleotide polymorphisms (SNPs) in and near IL6R to evaluate the likely causal effects of IL6R blockade on sepsis (primary outcome), sepsis severity, other infections, and COVID-19 (secondary outcomes). We weighted SNPs by their effect on CRP and combined results across them in inverse variance weighted meta-analysis, proxying the effect of IL6RA. Our outcomes were measured in UK Biobank, FinnGen, the COVID-19 Host Genetics Initiative (HGI), and the GenOSept and GainS consortium. We performed several sensitivity analyses to test assumptions of our methods, including utilising variants around CRP and gp130 in a similar analysis. In the UK Biobank cohort (N = 486,484, including 11,643 with sepsis), IL6R blockade was associated with a decreased risk of our primary outcome, sepsis (odds ratio (OR) = 0.80; 95% confidence interval (CI) 0.66 to 0.96, per unit of natural log-transformed CRP decrease). The size of this effect increased with severity, with larger effects on 28-day sepsis mortality (OR = 0.74; 95% CI 0.47 to 1.15); critical care admission with sepsis (OR = 0.48, 95% CI 0.30 to 0.78) and critical care death with sepsis (OR = 0.37, 95% CI 0.14 to 0.98). Similar associations were seen with severe respiratory infection: OR for pneumonia in critical care 0.69 (95% CI 0.49 to 0.97) and for sepsis survival in critical care (OR = 0.22; 95% CI 0.04 to 1.31) in the GainS and GenOSept consortium, although this result had a large degree of imprecision. We also confirm the previously reported protective effect of IL6R blockade on severe COVID-19 (OR = 0.69, 95% CI 0.57 to 0.84) in the COVID-19 HGI, which was of similar magnitude to that seen in sepsis. Sensitivity analyses did not alter our primary results. These results are subject to the limitations and assumptions of MR, which in this case reflects interpretation of these SNP effects as causally acting through blockade of IL6R, and reflect lifetime exposure to IL6R blockade, rather than the effect of therapeutic IL6R blockade.

CONCLUSIONS

IL6R blockade is causally associated with reduced incidence of sepsis. Similar but imprecisely estimated results supported a causal effect also on sepsis related mortality and critical care admission with sepsis. These effects are comparable in size to the effect seen in severe COVID-19, where IL-6 receptor antagonists were shown to improve survival. These data suggest that a randomised trial of IL-6 receptor antagonists in sepsis should be considered.

Interleukin-6 Signaling in Atherosclerosis: From Molecular Mechanisms To Clinical Outcomes

Interleukin-6 (IL-6) is a cytokine centrally involved in several immune responses and it has been recognized as a driver of enhanced atherothrombotic risk. Immunity and inflammation are intrinsically involved in atherosclerosis progression. This generated 'inflammation hypothesis', which is now validated in large-scale clinical trials. Abundant evidence supports the distinctive role of IL-6 in coronary artery disease. The focus on this cytokine stems from epidemiological studies linking high plasma concentrations of IL-6 with greater risk for adverse cardiovascular events, genetic studies which implicate a causative role of IL-6 in atherosclerosis and murine data which support the involvement of IL-6 in various pathophysiological cascades of atherothrombosis. The fact that high IL-6 levels are equivalent to increased cardiovascular risk created an unmet need to address those who are at 'residual inflammatory risk'. Moreover, the opposing effects of IL-6 underlined the importance of deciphering specific signaling cascades, which may be responsible for different effects. Finally, murine data and some small clinical trials highlighted the possibility of reversing the pro-atherogenic effects of IL-6 by directly targeting it. While IL-1 blockage was proved effective, it is reasonable to examine if moving more downstream in the inflammation cascade could be more selective and effective than other anti-inflammatory therapies. In the present review, we examine the role of IL-6 as a biomarker of 'residual inflammatory risk', its vital role in the pathophysiology of atherosclerosis progression and the possibility of targeting it to stall coronary artery disease progression.

Dissecting Interleukin-6 Classic and Trans-signaling in Inflammation and Cancer

Interleukin-6 (IL-6) is a cytokine synthesized by many cells in the human body. IL-6 binds to a membrane-bound receptor (IL-6R), which is only present on hepatocytes, some epithelial cells, and some leukocytes. The complex of IL-6 and IL-6R binds to the ubiquitously expressed receptor subunit gp130, which forms a homodimer and thereby initiates intracellular signaling, e.g., the JAK/STAT and MAPK pathways. Proteases can cleave the membrane-bound IL-6R from the cell surface and generate a soluble IL-6R (sIL-6R), which retains its ability to bind IL-6. The IL-6/sIL-6R complex associates with gp130 and induces signaling even on cells which do not express the IL-6R. This paradigm has been called IL-6 trans-signaling, whereas signaling via the membrane-bound IL-6R is referred to as classic signaling. We have generated several molecular tools to differentiate between both pathways and to analyze the consequences of cellular IL-6 signaling in vivo. One of these tools is soluble gp130Fc, which selectively inhibits IL-6 trans-signaling. This protein under the WHO name Olamkicept has successfully undergone phase II clinical trials in patients with autoimmune diseases. Here, in this chapter, we describe several molecular tools to differentiate between IL-6 classic and trans-signaling and to analyze the consequences of cellular IL-6 signaling in vivo.

Quo Vadis? Immunodynamics of Myeloid Cells after Myocardial Infarction

Myocardial infarction (MI), a major contributor to worldwide morbidity and mortality, is caused by a lack of blood flow to the heart. Affected heart tissue becomes ischemic due to deficiency of blood perfusion and oxygen delivery. In case sufficient blood flow cannot be timely restored, cardiac injury with necrosis occurs. The ischemic/necrotic area induces a systemic inflammatory response and hundreds of thousands of leukocytes are recruited from the blood to the injured heart. The blood pool of leukocytes is rapidly depleted and urgent re-supply of these cells is needed. Myeloid cells are generated in the bone marrow (BM) and spleen, released into the blood, travel to sites of need, extravasate and accumulate inside tissues to accomplish various functions. In this review we focus on the "leukocyte supply chain" and will separately evaluate different myeloid cell compartments (BM, spleen, blood, heart) in steady state and after MI. Moreover, we highlight the local and systemic kinetics of extracellular factors, chemokines and danger signals involved in the regulation of production/generation, release, transportation, uptake, and activation of myeloid cells during the inflammatory phase of MI.

Glucagon-like Peptide-1 receptor Tie2+ cells are essential for the cardioprotective actions of liraglutide in mice with experimental myocardial infarction

OBJECTIVES

Glucagon-like peptide-1 receptor (GLP-1R) agonists reduce the rates of major cardiovascular events, including myocardial infarction in people with type 2 diabetes, and decrease infarct size while preserving ventricular function in preclinical studies. Nevertheless, the precise cellular sites of GLP-1R expression that mediate the cardioprotective actions of GLP-1 in the setting of ischemic cardiac injury are uncertain.

METHODS

Publicly available single cell RNA sequencing (scRNA-seq) datasets on mouse and human heart cells were analyzed for Glp1r/GLP1R expression. Fluorescent activated cell sorting was used to localize Glp1r expression in cell populations from the mouse heart. The importance of endothelial and hematopoietic cells for the cardioprotective response to liraglutide in the setting of acute myocardial infarction (MI) was determined by inactivating the Glp1r in Tie2+ cell populations. Cardiac gene expression profiles regulated by liraglutide were examined using RNA-seq to interrogate mouse atria and both infarcted and non-infarcted ventricular tissue after acute coronary artery ligation.

RESULTS

In mice, cardiac Glp1r mRNA transcripts were exclusively detected in endocardial cells by scRNA-seq. In contrast, analysis of human heart by scRNA-seq localized GLP1R mRNA transcripts to populations of atrial and ventricular cardiomyocytes. Moreover, very low levels of GIPR, GCGR and GLP2R mRNA transcripts were detected in the human heart. Cell sorting and RNA analyses detected cardiac Glp1r expression in endothelial cells (ECs) within the atria and ventricle in the ischemic and non-ischemic mouse heart. Transcriptional responses to liraglutide administration were not evident in wild type mouse ventricles following acute MI, however liraglutide differentially regulated genes important for inflammation, cardiac repair, cell proliferation, and angiogenesis in the left atrium, while reducing circulating levels of IL-6 and KC/GRO within hours of acute MI. Inactivation of the Glp1r within the Tie2+ cell expression domain encompassing ECs revealed normal cardiac structure and function, glucose homeostasis and body weight in Glp1r^Tie2-/- mice. Nevertheless, the cardioprotective actions of liraglutide to reduce infarct size, augment ejection fraction, and improve survival after experimental myocardial infarction (MI), were attenuated in Glp1r^Tie2-/- mice.

CONCLUSIONS

These findings identify the importance of the murine Tie2+ endothelial cell GLP-1R as a target for the cardioprotective actions of GLP-1R agonists and support the importance of the atrial and ventricular endocardial GLP-1R as key sites of GLP-1 action in the ischemic mouse heart. Hitherto unexplored species-specific differences in cardiac GLP-1R expression challenge the exclusive use of mouse models for understanding the mechanisms of GLP-1 action in the normal and ischemic human heart.

Macrophages in myocardial infarction

The heart contains a population of resident macrophages that markedly expands following injury through recruitment of monocytes and through proliferation of macrophages. In myocardial infarction, macrophages have been implicated in both injurious and reparative responses. In coronary atherosclerotic lesions, macrophages have been implicated in disease progression and in the pathogenesis of plaque rupture. Following myocardial infarction, resident macrophages contribute to initiation and regulation of the inflammatory response. Phagocytosis and efferocytosis are major functions of macrophages during the inflammatory phase of infarct healing, and mediate phenotypic changes, leading to acquisition of an anti-inflammatory macrophage phenotype. Infarct macrophages respond to changes in the cytokine content and extracellular matrix composition of their environment and secrete fibrogenic and angiogenic mediators, playing a central role in repair of the infarcted heart. Macrophages may also play a role in scar maturation and may contribute to chronic adverse remodeling of noninfarcted segments. Single cell studies have revealed a remarkable heterogeneity of macrophage populations in infarcted hearts; however, the relations between transcriptomic profiles and functional properties remain poorly defined. This review manuscript discusses the fate, mechanisms of expansion and activation, and role of macrophages in the infarcted heart. Considering their critical role in injury, repair, and remodeling, macrophages are important, but challenging, targets for therapeutic interventions in myocardial infarction.

Targeting the NLRP3 inflammasome in cardiovascular diseases

The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that plays a major role in innate immunity. Following tissue injury, activation of the NLRP3 inflammasome results in cytokine production, primarily interleukin(IL)-1β and IL-18, and, eventually, inflammatory cell death - pyroptosis. While a balanced inflammatory response favors damage resolution and tissue healing, excessive NLRP3 activation causes detrimental effects. A key involvement of the NLRP3 inflammasome has been reported across a wide range of cardiovascular diseases (CVDs). Several pharmacological agents selectively targeting the NLRP3 inflammasome system have been developed and tested in animals and early phase human studies with overall promising results. While the NLRP3 inhibitors are in clinical development, multiple randomized trials have demonstrated the safety and efficacy of IL-1 blockade in atherothrombosis, heart failure and recurrent pericarditis. Furthermore, the non-selective NLRP3 inhibitor colchicine has been recently shown to significantly reduce cardiovascular events in patients with chronic coronary disease. In this review, we will outline the mechanisms driving NLRP3 assembly and activation, and discuss the pathogenetic role of the NLRP3 inflammasome in CVDs, providing an overview of the current and future therapeutic approaches targeting the NLRP3 inflammasome.

Meta-analysis reveals inhibition of the inflammatory cytokine IL-6 affords limited protection post-myocardial ischemia/infarction

Background

Proinflammatory cytokine cascades play crucial roles in the onset and progression of myocardial ischemia and infarction. Clinically, elevated serum levels of pro-inflammatory cytokine interleukin-6 is a poor prognostic indicator for future cardiac events and cardiac morbidity. Despite several reports, there is no clear evidence of cardiac benefits of inhibiting IL-6 in pre-clinical and clinical settings.

Objective

To analyze the available data systematically and perform a meta-analysis to show the evidence of effects of IL-6 inhibition on cardiac remodeling and mortality in ischemic animal models.

Methods

We used PICO framework and the quality of the studies was assessed using SYRCLE's risk of bias tool. Studies with interventions i.e., genetic deletion or pharmacological inhibition of IL-6/IL-6R were included for the meta-analysis. Systematic review was synthesized by including pre-clinical as well as randomized clinical trials involving myocardial infarction patients treated with IL-6 inhibitors. The effect size of the pooled data was determined using standard mean difference and 95% confidence intervals.

Results

A total of 12 pre-clinical studies were included in the review for analysis. Most of the studies showed an unclear risk of bias as the selection and reporting criteria were poorly described. We observed high heterogeneity in the included studies due to the varying duration of myocardial infarction and the dosage of IL-6 antibodies used in the studies. Overall inhibition of IL-6 significantly increased area at risk [p = 0.001, SMD = 0.49 (95% CI: -0.36, 1.35)] and significantly reduced ejection fraction [p = 0.001, SMD = -0.19 (95% CI: -1.39, 1.01)] and end-diastolic diameter [p = 0.02, SMD = -0.25 (95% CI: -0.87, 0.36)] of left ventricle post-MI, but no effects on infarct size [p < 0.01, SMD = 0.00; 95% CI: -1.34, 0.58). In randomized clinical trials, the overall effect on C-reactive protein remains significantly unchanged on CRP levels (SMD = -0.38; 95% CI: -1.94, 0.55) post-treatment with IL-6R inhibitor tocilizumab. The meta-regression demonstrates a significant positive correlation (p = 0.058) between the increase in ischemic area and duration of ischemia post-surgery in the absence of IL-6. This meta-analysis indicates mixed effect of IL-6 inhibition on cardiac remodeling post-MI, particularly in protecting the myocardium viability from damaging acute inflammation but not significant on cardiac function of ischemic animal models.

Conclusion

Despite the well-established pro-inflammatory nature of IL-6 in myocardial ischemia, our meta-analysis reports a limited contribution of IL-6 in the cardiac remodeling of hearts in animal models of myocardial ischemia. Moreover, genetically deleted IL-6 murine models produced contrasting results. Additional pre-clinical studies exploring the pharmacological inhibition of IL-6R are required to determine the beneficial effects of IL-6 inhibitors in regulating cardiac remodeling. The findings from IL-6R inhibition have better clinical relevance compared to genetically inhibited IL-6.

Case Report: Arterial Wall Inflammation in Atherosclerotic Cardiovascular Disease is Reduced by Olamkicept (sgp130Fc)

Inflammation is a strong driver of atherosclerotic cardiovascular disease (ASCVD). There is a large unmet need for therapies that prevent or reduce excessive inflammation while avoiding systemic immunosuppression. We showed previously that selective inhibition of pro-inflammatory interleukin-6 (IL-6) trans-signalling by the fusion protein olamkicept (sgp130Fc) prevented and reduced experimental murine atherosclerosis in low-density lipoprotein receptor-deficient (Ldlr^−/−) mice on a high-fat, high-cholesterol diet independently of low-density lipoprotein (LDL) cholesterol metabolism. Therefore, we allowed compassionate use of olamkicept (600 mg intravenously biweekly for 10 weeks) in a patient with very-high-risk ASCVD. Despite optimal LDL cholesterol under maximum tolerated lipid-lowering treatment, the patient had a remaining very high risk for future cardiovascular events related to significant arterial wall inflammation with lipoprotein (a) [Lp(a)]-cholesterol as the main contributor. ¹⁸Fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸FDG PET/CT) measurements were performed before and after the treatment period. Olamkicept reduced arterial wall inflammation in this patient without interfering with lipoprotein metabolism. No clinical or laboratory side effects were observed during or after treatment with olamkicept. Our findings in this patient matched the results from our mechanistic study in Ldlr^−/− mice, which were extended by additional analyses on vascular inflammation. Olamkicept may be a promising option for treating ASCVD independently of LDL cholesterol metabolism. A Phase II trial of olamkicept in ASCVD is currently being prepared.

Function and proteolytic generation of the soluble interleukin-6 receptor in health and disease

The pleiotropic cytokine interleukin-6 (IL-6) is involved in numerous physiological and pathophysiological functions that include development, immune cell differentiation, inflammation and cancer. IL-6 can signal via the membrane-bound IL-6 receptor (IL-6R, classic signaling) or via soluble forms of the IL-6R (sIL-6R, trans-signaling). Both modes of signaling induce the formation of a homodimer of the signal transducing β-receptor glycoprotein 130 (gp130) and the activation of several intracellular signaling cascades, e.g. the Jak/STAT pathway. Intriguingly, only IL-6 trans-signaling is required for the pro-inflammatory properties of IL-6, while regenerative and anti-inflammatory functions are mediated via classic signaling. The sIL-6R is generated by different molecular mechanisms, including alternative mRNA splicing, proteolysis of the membrane-bound IL-6R and the release of extracellular vesicles. In this review, we give an in-depth overview on these molecular mechanisms with a special emphasize on IL-6R cleavage by the metalloprotease ADAM17 and other proteases. We discuss the biological functions of the sIL-6R and highlight attempts to selectively block IL-6 trans-signaling in pre-clinical animal models as well as in clinical studies in patients with inflammatory bowel disease.

Blocking only the bad side of IL-6 in inflammation and cancer

Interleukin-6 (IL-6) is considered an inflammatory cytokine, which is involved not only in most inflammatory states but it also plays a prominent role in inflammation associated cancers. The response of cells to the cytokine strictly depends on the presence of the IL-6 receptor (IL-6R),which presents IL-6 to the signal transducing receptor subunit gp130, which is expressed on all cells of the body. The expression of IL-6R is limited to some cells, which are therefore IL-6 target cells. The IL-6R can be cleaved by proteases and the thus generated soluble IL-6R (sIL-6R) still binds the ligand IL-6. The complex of IL-6 and sIL-6R can bind to gp130 on any cell, induce dimerization of gp130 and intracellular signaling. This process has been named IL-6 trans-signaling. A fusion protein of soluble gp130 with the constant portion of human IgG1 (sgp130Fc) turned out to be a potent and specific inhibitor of IL-6 trans-signaling. In many animal models of human diseases the significance of IL-6 trans-signaling has been analyzed. It turned out that the activities of IL-6 mediated by the sIL-6R are the pro-inflammatory activities of the cytokine whereas activities of IL-6 mediated by the membrane-bound IL-6R are rather protective and regenerative. The sgp130Fc protein has recently been developed into a biologic. The possible consequences of a specific IL-6 trans-signaling blockade is discussed in the light of the recent successfully concluded phase II clinical trials in patients with inflammatory bowel disease.