Toll-like receptor 2 is overexpressed in Familial Mediterranean fever patients and is inhibited by colchicine treatment

Emerging insights into the role of IL-1 inhibitors and colchicine for inflammation control in type 2 diabetes

Type 2 diabetes mellitus (T2DM), a prevalent chronic metabolic disorder, is closely linked to persistent low-grade inflammation, significantly contributing to its development and progression. This review provides a comprehensive examination of the inflammatory mechanisms underlying T2DM, focusing on the role of the NLRP3 inflammasome and interleukin-1β (IL-1β) in mediating inflammatory responses. We discuss the therapeutic potential of IL-1 inhibitors and colchicine, highlighting their mechanisms in inhibiting the NLRP3 inflammasome and reducing IL-1β production. Recent studies indicate that these agents could effectively mitigate inflammation, offering promising avenues for the prevention and management of T2DM. By exploring the intricate connections between metabolic disturbances and chronic inflammation, this review underscores the need for novel anti-inflammatory strategies to address T2DM and its complications.

Epigenetic, transcriptional, and functional characterization of myeloid cells in familial Mediterranean fever

Familial Mediterranean fever (FMF) is a periodic fever syndrome caused by variation in MEFV. FMF is known for IL-1β dysregulation, but the innate immune landscape of this disease has not been comprehensively described. Therefore, we studied circulating inflammatory proteins, and the function of monocytes and (albeit less extensively) neutrophils in treated FMF patients in remission. We found that monocyte IL-1β and IL-6 production was enhanced upon stimulation, in concordance with alterations in the plasma inflammatory proteome. We did not observe changes in neutrophil functional assays. Subtle differences in chromatin accessibility and transcriptomics in our small patient cohort further argued for monocyte dysregulation. Together, these observations suggest that the MEFV-mutation-mediated primary immune dysregulation in monocytes leads to chronic inflammation that is subsequently associated with counterregulatory epigenetic/transcriptional changes reminiscent of tolerance. These data increase our understanding of the innate immune changes in FMF, aiding future management of chronic inflammation in these patients.

A mathematical model of Familial Mediterranean Fever predicts mechanisms controlling inflammation

BACKGROUND

Familial Mediterranean Fever (FMF) is a monogenic disease caused by gain-of-function mutations in the MEditerranean FeVer (MEFV) gene. The molecular dysregulations induced by these mutations and the associated causal mechanisms are complex and intricate.

OBJECTIVE

We sought to provide a computational model capturing the mechanistic details of biological pathways involved in FMF physiopathology and enabling the study of the patient's immune cell dynamics.

METHODS

We carried out a literature survey to identify experimental studies published from January 2000 to December 2020, and integrated its results into a molecular map and a mathematical model. Then, we studied the network of molecular interactions and the dynamic of monocytes to identify key players for inflammation phenotype in FMF patients.

RESULTS

We built a molecular map of FMF integrating in a structured manner the current knowledge regarding pathophysiological processes participating in the triggering and perpetuation of the disease flares. The mathematical model derived from the map reproduced patient's monocyte behavior, in particular its proinflammatory role via the Pyrin inflammasome activation. Network analysis and in silico experiments identified NF-κB and JAK1/TYK2 as critical to modulate IL-1β- and IL-18-mediated inflammation.

CONCLUSION

The in silico model of FMF monocyte proved its ability to reproduce in vitro observations. Considering the difficulties related to experimental settings and financial investments to test combinations of stimuli/perturbation in vitro, this model could be used to test complex hypotheses in silico, thus narrowing down the number of in vitro and ex vivo experiments to perform.

Therapeutic potential of colchicine in cardiovascular medicine: a pharmacological review

Colchicine is an ancient herbal drug derived from Colchicum autumnale. It was first used to treat familial Mediterranean fever and gout. Based on its unique efficacy as an anti-inflammatory agent, colchicine has been used in the therapy of cardiovascular diseases including coronary artery disease, atherosclerosis, recurrent pericarditis, vascular restenosis, heart failure, and myocardial infarction. More recently, colchicine has also shown therapeutic efficacy in alleviating cardiovascular complications of COVID-19. COLCOT and LoDoCo2 are two milestone clinical trials that confirm the curative effect of long-term administration of colchicine in reducing the incidence of cardiovascular events in patients with coronary artery disease. There is growing interest in studying the anti-inflammatory mechanisms of colchicine. The anti-inflammatory action of colchicine is mediated mainly through inhibiting the assembly of microtubules. At the cellular level, colchicine inhibits the following: (1) endothelial cell dysfunction and inflammation; (2) smooth muscle cell proliferation and migration; (3) macrophage chemotaxis, migration, and adhesion; (4) platelet activation. At the molecular level, colchicine reduces proinflammatory cytokine release and inhibits NF-κB signaling and NLRP3 inflammasome activation. In this review, we summarize the current clinical trials with proven curative effect of colchicine in treating cardiovascular diseases. We also systematically discuss the mechanisms of colchicine action in cardiovascular therapeutics. Altogether, colchicine, a bioactive constituent from an ancient medicinal herb, exerts unique anti-inflammatory effects and prominent cardiovascular actions, and will charter a new page in cardiovascular medicine.

Safety of the BNT162b2 mRNA COVID-19 vaccine in patients with familial Mediterranean fever

OBJECTIVES

Evidence suggests a possible association between the COVID-19 vaccine and autoimmune disease flares or new onset of various autoinflammatory manifestations, such as pericarditis and myocarditis. The objective of this study was to assess the safety of an mRNA-based BNT162b2 anti-COVID-19 vaccine in individuals with familial Mediterranean fever (FMF), a prototypic autoinflammatory disease.

METHODS

Patients participating in this study fulfilled the criteria for diagnosis of FMF, were older than 18 years, and received at least one dose of the vaccine. Data on baseline characteristics, features of FMF, post-vaccination side effects, and disease flares were acquired using electronic medical files and telephone interviews.

RESULTS

A total of 273 FMF patients were recruited for the study. More than 95% were vaccinated with two doses of the vaccine. The rates of local reactions following the first and second vaccine doses were 65.5% and 60%, respectively, and 26% and 50.4%, respectively, for systemic adverse events. These rates are lower than those reported for the general population from real-world and clinical trial settings. Postvaccination FMF activity remained stable in most patients. None of the patients reported an attack of pericarditis or myocarditis, considered the most serious vaccine-associated adverse events. Patients with a more active FMF disease and patients harboring the M694V mutation had a significantly higher rate of post-vaccination systemic side effects and attacks.

CONCLUSION

The BNT162b2 mRNA Covid-19 vaccine is safe in patients with FMF. Our results support the administration of this vaccine to FMF patients according to guidelines applicable to the general population.

Tripterine ameliorates monosodium urate crystal-induced gouty arthritis by altering macrophage polarization via the miR-449a/NLRP3 axis

OBJECTIVE

Tripterine (Trip) is frequently applied to alleviate inflammation in various diseases such as rheumatoid arthritis. Macrophages have both anti-inflammatory and pro-inflammatory functions. However, whether Trip can inhibit cell inflammation in gouty arthritis (GA) remains undiscovered and whether the mechanism involved in macrophage polarization is also undetermined. This paper aims to study the effects of Trip on inflammation and macrophage polarization in GA.

METHODS

Monosodium urate (MSU) crystals were used to establish GA mouse models, and bone marrow-derived macrophages (BMDMs) were induced to construct GA cell models. Pretreatments of Trip and injection of Antagomir-449a/Agomir-449a were performed on mice for 6 days. The effects of Trip and miR-449 on toe swelling, joint damage of GA mouse were examined. The alternations on cell morphology, cell proliferation marker Ki67, inflammatory cytokines, NLRP3 inflammasome, and NF-κB signaling-related proteins were also determined both in vivo and in vitro. Dual-luciferase reporter gene assay and RIP assay were adopted to estimate the targeting relationship between miR-449a and NLRP3.

RESULTS

GA mouse model had increased M1 macrophage, intensified inflammation response, along with suppressed miR-449a expression. Following administration of Trip attenuated cell inflammation, promoted macrophage polarize to M2 phenotype, elevated miR-449a expression, repressed the phosphorylation levels of NF-κB signaling-related proteins, and diminished IκBα expression in vivo and in vitro. However, inhibition of miR-449a hindered the favorable effect of Trip on GA and increased NLRP3 inflammasome expression. MiR-449a directly targeted NLRP3. Overexpression of NLRP3 partially eliminated the biological effects of miR-449a agonist.

CONCLUSION

Trip regulates macrophage polarization through miR-449a/NLRP3 axis and the STAT3/NF-κB pathway to mitigate GA. The elucidation on the molecular mechanism of Trip in GA may provide theoretical guidance for clinical therapy of GA.

Familial Mediterranean fever: the molecular pathways from stress exposure to attacks

FMF is an autoinflammatory disease characterized by recurrent attacks and increased IL-1 synthesis owing to activation of the pyrin inflammasome. Although knowledge of the mechanisms leading to the activation of pyrin inflammasome is increasing, it is still unknown why the disease is characterized by attack. The emergence of FMF attacks after emotional stress and the induction of attacks with metaraminol in previous decades suggested that stress-induced sympathoadrenal system activation might play a role in inflammasome activation and triggering attacks. In this review, we will review the possible molecular mechanism of stress mediators on the inflammation pathway and inflammasome activation. Studies on stress mediators and their impact on inflammation pathways will provide a better understanding of stress-related exacerbation mechanisms in both autoinflammatory and autoimmune diseases. This review provides a new perspective on this subject and will contribute to new studies.

Prognostic and therapeutic considerations of antibodies against c-ter apolipoprotein A-1 in the general population

Objectives

Autoantibodies against apolipoprotein A1 (anti-apoA1 IgGs) and its C-terminal region (cter apoA1) have emerged as an independent biomarker for cardiovascular disease. Cter apoA1 mimetic peptides were shown to reverse the deleterious anti-apoA1 IgG effects in vitro. We evaluated the association of anti-cter apoA1 IgGs with overall mortality in the general population and tested the ability of a cter apoA1 mimetic peptide to reverse the anti-apoA1 IgG-induced inflammatory response and mortality in vitro and in vivo, respectively.

Methods

Anti-cter apoA1 IgGs were measured in serum samples of 6386 participants of the CoLaus study of which 5220 were followed for a median duration of 5.6 years. The primary outcome was overall mortality. The peptide inhibitory concentration 50% (IC₅₀) was determined in vitro on HEK-Blue-4 and RAW cells. ApoE^-/- mice were exposed to 16 weeks of anti-apoA1IgG passive immunisation with and without peptide co-incubation.

Results

Anti-cter apoA1 IgGs were associated with higher interleukin 6 levels and independently predicted overall mortality; an increase of one standard deviation of anti-cter apoA1 IgG level was associated with an 18% increase in mortality risk (hazard ratio: 1.18, 95% confidence interval: 1.04-1.33; P = 0.009). The cterApoA1 analogue reversed the antibody-mediated inflammatory response with an IC₅₀ of 1 µm in vitro but did not rescue the significant anti-apoA1 IgG-induced mortality rate in vivo (69% vs. 23%, LogRank P = 0.02).

Conclusion

Anti-cter apoA1 IgG independently predicts overall mortality in the general population. Despite being effective in vitro, our cter apoA1 analogue did not reverse the anti-apoA1 IgG-induced mortality in mice. Our data suggest that these autoantibodies are not readily treatable through cognate peptide immunomodulation.

Evaluation of a Proarrhythmic Repolarization Marker (Total Cosine R to T) in Patients With Uncomplicated Familial Mediterranean Fever

Familial Mediterranean fever (FMF) is a systemic autoinflammatory disorder characterized by recurrent attacks of fever and serous inflammation. The association between FMF and risk of cardiac arrhythmia is continuously questioned; some studies report abnormal cardiac repolarization, while others do not. Considering this controversy, we aim to perform in a large cohort of FMF patients a total cosine R to T (TCRT) analysis, a previously unexplored repolarization marker in this disorder.

METHODS

The study group included 56 FMF patients without amyloidosis, diagnosed with FMF according to published criteria and 131 control subjects, unaffected with FMF. A 12-lead electrocardiogram (ECG) was performed according to strict standards. Electrocardiogram files were processed with Python-based computer software. Patients were followed for 10 to 12 years, and the rate of cardiac complications was evaluated.

RESULTS

Other than FMF and prescription of colchicine, both groups had similar medical and demographic background. TCRT results were similar for a randomly selected beat (0.40 ± 0.06 vs 0.50 ± 0.04, p > 0.05) and for an averaged beat (0.39 ± 0.06 vs 0.50 ± 0.04, p > 0.05) in FMF patients and control subjects, respectively. Correction of average TCRT for heart rate also resulted in similar TCRTc values in patients and control groups (0.42 ± 0.07 s vs 0.51 ± 0.05 s, respectively, p > 0.05). During the follow-up period, none of the patients died, and no patient developed clinical symptoms suggestive of ventricular arrhythmias.

CONCLUSIONS

Colchicine treated uncomplicated FMF patients have normal TCRT and TCRTc values, implying low risk for cardiac arrhythmias in this population. Future studies should evaluate the sensitivity and specificity of this marker in high-risk FMF populations, such as those who developed AA amyloidosis.

Familial Mediterranean Fever: Clinical State Of The Art

As the inflammation research improves year by year, so does our understanding of the autoinflammatory conditions. Over the past years, the number of monogenic autoinflammatory conditions snowballed thanks to our understanding of basic immunology and genetics. Familial Mediterranean Fever (FMF), being the entrance to this fascinating world, still has clinical relevance as it enables us to understand our approach to these patients, treatment modalities, and pathological mechanisms. This review can be used as a tool for clinicians already working with FMF patients to update themselves on recent scientific literature.

TLR expression in peripheral monocyte subsets of patients with idiopathic inflammatory myopathies: association with clinical and immunological features

BACKGROUND

Monocytes and toll-like receptors (TLR) have been found in the inflammatory infiltrate of muscle biopsies in patients with idiopathic inflammatory myopathies (IIM), suggesting an important role of these cells in the pathogenesis of myositis. The monocyte subsets, their TLR expression in peripheral blood and their relationship with the clinical characteristics of patients with IIM has not been addressed.

METHODS

We recruited 45 patients with IIM diagnosis and 15 age and sex-adjusted healthy controls. We assessed the disease activity and damage, performed a nailfold capillaroscopy and registered the cardio-pulmonary parameters from the medical charts. Monocyte subsets, their expression of TLR2 and TLR4 and the serum Th1/Th2/Th17 cytokines levels were evaluated by flow cytometry. We expressed quantitative variables as medians and interquartile ranges (IQR) or minimum and maximum (min-max). Differences between groups were assessed with Mann-Whitney U and the Kruskal-Wallis tests. Correlation between quantitative variables was assessed with Spearman Rho.

RESULTS

Twenty-nine patients were women (64.4%) and 32 (71.1%) had dermatomyositis. In comparison to healthy controls, patients with active IIM had a higher percentage of intermediate monocytes and lower amounts of classical monocytes. Patients with IIM had a higher expression of TLR4 in all their monocyte subsets, regardless of disease activity and prednisone treatment. Serum IL-6 correlated with the TLR2 expression in every monocyte subset and the expression of TLR2 in intermediate monocytes was higher among patients with dysphagia. Subjects with nailfold capillaroscopy abnormalities had a higher amount of TLR2+ classical and non-classical monocytes and those with interstitial lung disease (ILD) had a higher percentage of TLR4+ non-classical monocytes. The classical and intermediate monocytes from patients with anti Mi2 antibodies had a higher expression of TLR4. The percentage of intermediate monocytes and the expression of TLR4 in all monocyte subsets showed a good diagnostic capacity in patients with IIM.

CONCLUSION

Patients with IIM have a differential pool of monocyte subsets with an enhanced expression of TLR2 and TLR4, which correlates with disease activity and distinctive clinical features including dysphagia, ILD, vasculopathy, and pro-inflammatory cytokines. These immunological features might be useful as a potential diagnostic tool as well as novel disease activity biomarkers in IIM.