The NLRP3 inflammasome and the emerging role of colchicine to inhibit atherosclerosis-associated inflammation

Purinergic Signaling in Controlling Macrophage and T Cell Functions During Atherosclerosis Development

Atherosclerosis is a hardening and narrowing of arteries causing a reduction of blood flow. It is a leading cause of death in industrialized countries as it causes heart attacks, strokes, and peripheral vascular disease. Pathogenesis of the atherosclerotic lesion (atheroma) relies on the accumulation of cholesterol-containing low-density lipoproteins (LDL) and on changes of artery endothelium that becomes adhesive for monocytes and lymphocytes. Immunomediated inflammatory response stimulated by lipoprotein oxidation, cytokine secretion and release of pro-inflammatory mediators, worsens the pathological context by amplifying tissue damage to the arterial lining and increasing flow-limiting stenosis. Formation of thrombi upon rupture of the endothelium and the fibrous cup may also occur, triggering thrombosis often threatening the patient’s life. Purinergic signaling, i.e., cell responses induced by stimulation of P2 and P1 membrane receptors for the extracellular nucleotides (ATP, ADP, UTP, and UDP) and nucleosides (adenosine), has been implicated in modulating the immunological response in atherosclerotic cardiovascular disease. In this review we will describe advancements in the understanding of purinergic modulation of the two main immune cells involved in atherogenesis, i.e., monocytes/macrophages and T lymphocytes, highlighting modulation of pro- and anti-atherosclerotic mediated responses of purinergic signaling in these cells and providing new insights to point out their potential clinical significance.

Anti-inflammatory Therapy for Coronary Atherosclerotic Heart Disease: Unanswered Questions Behind Existing Successes

Coronary atherosclerotic heart disease is a serious threat to human health. The results of the Canakinumab Anti-Inflammatory Thrombosis Outcome Study published in 2017 put an end to the perennial debate about the anti-inflammatory treatment of coronary atherosclerotic heart disease. In addition to interleukin 1β monoclonal antibody, interleukin 6 receptor antagonists and colchicine have also shown exciting results in clinical trials within the last 3 years. However, behind these successes, questions remain that need to be addressed. In this review, we summarize the successes and existing doubts of interleukin 1β antibodies, interleukin 6 receptor antagonists, and colchicine in the anti-inflammatory treatment of coronary atherosclerotic heart disease.

Immunomodulation of the NLRP3 Inflammasome in Atherosclerosis, Coronary Artery Disease, and Acute Myocardial Infarction

Cardiovascular disease (CVD) remains the leading cause of mortality and morbidity worldwide. Atherosclerosis is responsible for the majority of cardiovascular disorders with inflammation as one of its driving processes. The nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3) inflammasome, responsible for the release of the pro-inflammatory cytokines, interleukin-1β (IL-1β), and interleukin-18 (IL-18), has been studied extensively and showed to play a pivotal role in the progression of atherosclerosis, coronary artery disease (CAD), and myocardial ischemia reperfusion (I/R) injury. Both the NLRP3 inflammasome and its downstream cytokines, IL-1ß and IL-18, could therefore be promising targets in cardiovascular disease. This review summarizes the role of the NLRP3 inflammasome in atherosclerosis, CAD, and myocardial I/R injury. Furthermore, the current therapeutic approaches targeting the NLRP3 inflammasome and its downstream signaling cascade in atherosclerosis, CAD, and myocardial I/R injury are discussed.

Mitochondrial DAMPs and altered mitochondrial dynamics in OxLDL burden in atherosclerosis

Atherosclerosis results in life-threatening cardiovascular pathologies, including ischemic heart disease, stroke, myocardial infarction, and peripheral arterial disease. The role of increased serum low-density lipoprotein (LDL) and resultant accumulation of oxidized-LDL (oxLDL) in atheroma formation is well established. Recent findings elucidate the significance of mitochondrial damage-associated molecular patterns (mtDAMPs) in triggering sterile inflammation in concert with oxLDL. The mtDAMPs including mitochondrial DNA (mtDNA), cytochrome C, cardiolipin, heat shock protein 60 (HSP60), mitochondrial transcription factor A (TFAM), and N-formyl peptides, are expected to possess proatherogenic roles. However, limited data are available in the literature. The mtDAMPs initiate sterile inflammation in atherosclerotic lesions via numerous signaling pathways, most of which converge to the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome. Priming the activation of the NLRP3 inflammasome, mtDAMPs promote secretion of proinflammatory cytokines, including interleukin-1β (IL-1β), implicated in atherosclerotic lesions through vascular smooth muscle and fibroblast proliferation, arterial wall thickening, and plaque formation. In this article we critically reviewed and discussed the central role of the NLRP3 inflammasome in mtDAMP-induced sterile inflammation in atherosclerosis with specific components including caspase-1, pregnane X receptor (PXR), adenosine monophosphate activated protein kinase (AMPK), protein phosphatase 2A (PP2A), thioredoxin-interacting protein (TXNIP), and downstream cytokines including IL-1β and IL-18 as potential mediators of atherosclerosis. Better understanding of the proinflammatory effects of mtDAMPs and its pathological association with oxLDL possess immense translational significance for novel therapeutic intervention.

The Role of Colchicine in Atherosclerotic Cardiovascular Disease

Colchicine, an inexpensive immunomodulatory drug used traditionally to treat gout and familial Mediterranean fever, is rapidly accumulating basic and clinical evidence for a therapeutic role in atherosclerotic cardiovascular disease. Its athero-protective properties are thought to be mainly related to its effect on tubulin polymerisation, enabling a broad range of effect on multiple atherosclerotic plaque cell types and cellular processes, including cell division, cell migration as well as pro-inflammatory cytokine and chemokine secretion. These properties indicate the potential to favourably affect all stages of atherosclerotic plaque development including formation, progression, destabilisation, and plaque rupture. This review focusses on the pharmacology of colchicine, the mechanisms by which it modulates atherosclerosis pathobiology, and summarises the current clinical evidence for its use along with the upcoming clinical trial landscape. Given the current lack of primary immunomodulatory drugs in the treatment of atherosclerosis, colchicine is a promising candidate to fill this therapeutic gap.

Colchicine reduces lung injury in experimental acute respiratory distress syndrome

The acute respiratory distress syndrome (ARDS) is characterized by intense dysregulated inflammation leading to acute lung injury (ALI) and respiratory failure. There are no effective pharmacologic therapies for ARDS. Colchicine is a low-cost, widely available drug, effective in the treatment of inflammatory conditions. We studied the effects of colchicine pre-treatment on oleic acid-induced ARDS in rats. Rats were treated with colchicine (1 mg/kg) or placebo for three days prior to intravenous oleic acid-induced ALI (150 mg/kg). Four hours later they were studied and compared to a sham group. Colchicine reduced the area of histological lung injury by 61%, reduced lung edema, and markedly improved oxygenation by increasing PaO2/FiO2 from 66 ± 13 mmHg (mean ± SEM) to 246 ± 45 mmHg compared to 380 ± 18 mmHg in sham animals. Colchicine also reduced PaCO2 and respiratory acidosis. Lung neutrophil recruitment, assessed by myeloperoxidase immunostaining, was greatly increased after injury from 1.16 ± 0.19% to 8.86 ± 0.66% and significantly reduced by colchicine to 5.95 ± 1.13%. Increased lung NETosis was also reduced by therapy. Circulating leukocytosis after ALI was not reduced by colchicine therapy, but neutrophils reactivity and CD4 and CD8 cell surface expression on lymphocyte populations were restored. Colchicine reduces ALI and respiratory failure in experimental ARDS in relation with reduced lung neutrophil recruitment and reduced circulating leukocyte activation. This study supports the clinical development of colchicine for the prevention of ARDS in conditions causing ALI.

Single-Cell Immune Profiling in Coronary Artery Disease: The Role of State-of-the-Art Immunophenotyping With Mass Cytometry in the Diagnosis of Atherosclerosis

Coronary artery disease remains the leading cause of death globally and is a major burden to every health system in the world. There have been significant improvements in risk modification, treatments, and mortality; however, our ability to detect asymptomatic disease for early intervention remains limited. Recent discoveries regarding the inflammatory nature of atherosclerosis have prompted investigation into new methods of diagnosis and treatment of coronary artery disease. This article reviews some of the highlights of the important developments in cardioimmunology and summarizes the clinical evidence linking the immune system and atherosclerosis. It provides an overview of the major serological biomarkers that have been associated with atherosclerosis, noting the limitations of these markers attributable to low specificity, and then contrasts these serological markers with the circulating immune cell subtypes that have been found to be altered in coronary artery disease. This review then outlines the technique of mass cytometry and its ability to provide high-dimensional single-cell data and explores how this high-resolution quantification of specific immune cell subpopulations may assist in the diagnosis of early atherosclerosis in combination with other complimentary techniques such as single-cell RNA sequencing. We propose that this improved specificity has the potential to transform the detection of coronary artery disease in its early phases, facilitating targeted preventative approaches in the precision medicine era.

Inflammation and cardiovascular disease: From mechanisms to therapeutics

Inflammation constitutes a complex, highly conserved cascade of molecular and cellular events. Inflammation has been labeled as “the fire within,” is highly regulated, and is critical to host defense and tissue repair. In general, inflammation is beneficial and has evolved to promote survival. However, inflammation can also be maladaptive when chronically activated and sustained, leading to progressive tissue injury and reduced survival. Examples of a maladaptive response include rheumatologic disease and atherosclerosis. Despite evidence gathered by Virchow over 100 years ago showing that inflammatory white cells play a role in atherogenesis, atherosclerosis was until recently viewed as a disease of passive cholesterol accumulation in the subendothelial space. This view has been supplanted by considerable basic scientific and clinical evidence demonstrating that every step of atherogenesis, from the development of endothelial cell dysfunction to foam cell formation, plaque formation and progression, and ultimately plaque rupture stemming from architectural instability, is driven by the cytokines, interleukins, and cellular constituents of the inflammatory response. Herein we provide an overview of the role of inflammation in atherosclerotic cardiovascular disease, discuss the predictive value of various biomarkers involved in inflammation, and summarize recent clinical trials that evaluated the capacity of various pharmacologic interventions to attenuate the intensity of inflammation and impact risk for acute cardiovascular events.

Colchicine in Patients With Acute Coronary Syndrome

Background:

Inflammation plays a crucial role in clinical manifestations and complications of acute coronary syndromes (ACS). Colchicine, a commonly used treatment for gout, has recently emerged as a novel therapeutic option in cardiovascular medicine owing to its anti-inflammatory properties. We sought to determine the potential usefulness of colchicine treatment in patients with ACS.

Methods:

This was a multicenter, randomized, double-blind, placebo-controlled trial involving 17 hospitals in Australia that provide acute cardiac care service. Eligible participants were adults (18–85 years) who presented with ACS and had evidence of coronary artery disease on coronary angiography managed with either percutaneous coronary intervention or medical therapy. Patients were assigned to receive either colchicine (0.5 mg twice daily for the first month, then 0.5 mg daily for 11 months) or placebo, in addition to standard secondary prevention pharmacotherapy, and were followed up for a minimum of 12 months. The primary outcome was a composite of all-cause mortality, ACS, ischemia-driven (unplanned) urgent revascularization, and noncardioembolic ischemic stroke in a time to event analysis.

Results:

A total of 795 patients were recruited between December 2015 and September 2018 (mean age, 59.8±10.3 years; 21% female), with 396 assigned to the colchicine group and 399 to the placebo group. Over the 12-month follow-up, there were 24 events in the colchicine group compared with 38 events in the placebo group ( P =0.09, log-rank). There was a higher rate of total death (8 versus 1; P =0.017, log-rank) and, in particular, noncardiovascular death in the colchicine group (5 versus 0; P =0.024, log-rank). The rates of reported adverse effects were not different (colchicine 23.0% versus placebo 24.3%), and they were predominantly gastrointestinal symptoms (colchicine, 23.0% versus placebo, 20.8%).

Conclusions:

The addition of colchicine to standard medical therapy did not significantly affect cardiovascular outcomes at 12 months in patients with ACS and was associated with a higher rate of mortality.

Registration:

URL: https://www.anzctr.org.au ; Unique identifier: ACTRN12615000861550.

Combining Antivirals and Immunomodulators to Fight COVID-19

The majority of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals remain paucisymptomatic, contrasting with a minority of infected individuals in danger of death. Here, we speculate that the robust disease resistance of most individuals is due to a swift production of type I interferon (IFNα/β), presumably sufficient to lower the viremia. A minority of infected individuals with a preexisting chronic inflammatory state fail to mount this early efficient response, leading to a delayed harmful inflammatory response. To improve the epidemiological scenario, we propose combining: (i) the development of efficient antivirals administered early enough to assist in the production of endogenous IFNα/β; (ii) potentiating early IFN responses; (iii) administering anti-inflammatory treatments when needed, but not too early to interfere with endogenous antiviral responses.

Although the coronavirus disease 2019 (COVID-19) pandemic is exceptional, lessons may be learned from previous outbreaks (coronavirus, dengue, influenza viruses), especially when considering drug design and cytokine storms.

We propose that efficient treatments for COVID-19 patients should combine antivirals and immunomodulators. This combination and, especially the use of immunomodulators, might be adapted according to the disease stage.

Among the repurposed antiviral drugs currently being tested against COVID-19, none shows high potency.

We posit that the innate type 1 interferon (IFNα/β)-dependent antiviral immune response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection should be amplified. To this end, we propose two putative approaches: the inhibition of transforming growth factor (TGFβ) signaling, and perhaps, the administration of 1,8-cineole.

We suggest that an early diagnosis during COVID-19 is essential when aiming to purposely combine antivirals with the use of an immunomodulator (e.g., a drug to potentiate IFNα/β), ideally early in the disease course to lower the risk of cytokine storm manifestation. When the disease becomes severe, the new combination should prioritize targeting of the cytokine storm.

Downregulating lncRNA PRNCR1 ameliorates LPS-induced pulmonary vascular endothelial cell injury by modulating miR-330-5p/TLR4 axis

Pulmonary vascular endothelial cell (PVEC) injury following acute lung injury or acute respiratory distress syndrome seriously affects disease development. Recently, accumulating evidence has suggested that long noncoding RNA (lncRNA) exerts significant effects in vascular endothelial cell injury. However, PRNCR1, a novel lncRNA, remains scarcely understood in terms of its functions in PVEC injury. Both in vivo and in vitro models of PVEC injury were constructed by lipopolysaccharide (LPS) administration. The relative expressions of PRNCR1, miR-330-5p, and TLR4 were detected by quantitative reverse transcription-polymerase chain reaction, Western blot, and immunohistochemistry. Besides, gain and loss assays of PRNCR1/miR-330-5p were conducted to verify their effects on LPS-induced PVEC injury. Cell Counting Kit-8 assay used to measure cell viability and flow cytometry was used to detect apoptosis. Besides, the protein levels of caspase 3, nuclear factor-κB (NF-κB), and inflammatory cytokines (including tumor necrosis factor-α, interleukin-1β [IL-1β], and IL-6) were evaluated via Western blot and enzyme-linked immunosorbent assay. Moreover, a dual-luciferase activity experiment and RNA immunoprecipitation were applied to confirm the targeting relationship between PRNCR1 and miR-330-5p, miR-330-5p, and TLR4. PRNCR1 and TLR4 levels were significantly upregulated in LPS-treated PVEC, both in vivo and in vitro, while miR-330-5p were downregulated. Inhibiting PRNCR1 or overexpressing miR-330-5p markedly attenuated LPS-induced PVEC injury, expressions of TLR4, NF-κB, and inflammatory cytokines. Mechanistically, PRNCR1 functioned as a competitive endogenous RNA by sponging miR-330-5p and then promoting TLR4 expression. PRNCR1 was upregulated in LPS-induced PVEC and aggravated its injury via modulating the miR-330-5p/TLR4 axis.

[Proactive anti-inflammatory and anticoagulant therapy in the treatment of advanced stages of novel coronavirus infection (COVID-19). Case Series and Study Design: COLchicine versus ruxolitinib and secukinumab in open prospective randomIzed trial (COLORIT)]

The article is devoted to the treatment of the new coronavirus infection (COVID-19) in the advanced stages of the disease. The types of response of the immune system to the viral load of SARS-CoV-2 with the start of the inflammation process are considered. The situation is analyzed in detail in which the growing autoimmune inflammation (up to the development of a "cytokine storm") affects not only the pulmonary parenchyma, but also the endothelium of the small vessels of the lungs. Simultaneous damage to the alveoli and microthrombosis of the pulmonary vessels are accompanied by a progressive impairment of gas exchange, the development of acute respiratory distress syndrome, the treatment of which, even with the use of invasive ventilation, is ineffective and does not really change the prognosis of patients with COVID-19. In order to interrupt the pathological process at the earliest stages of the disease, the necessity of proactive anti-inflammatory therapy in combination with active anticoagulation treatment is substantiated. The results of the first randomized studies on the use of inhibitors of pro-inflammatory cytokines and chemokines (interleukin-6 (tocilizumab), interleukin-17 (secukinumab), Janus kinase blockers, through which the signal is transmitted to cells (ruxolitinib)), which have potential in the early treatment of COVID- 19. The use of a well-known anti-inflammatory drug colchicine (which is used for gout treatment) in patients with COVID-19 is considered. The design of the original COLORIT comparative study on the use of colchicine, ruxolitinib and secukinumab in the treatment of COVID-19 is presented. Clinical series presented, illustrated early anti-inflammatory therapy together with anticoagulants in patients with COVID-19 and the dangers associated with refusing to initiate such therapy on time.

Lipoxin A4 Inhibits NLRP3 Inflammasome Activation in Rats With Non-compressive Disc Herniation Through the JNK1/Beclin-1/PI3KC3 Pathway

Background

Non-compressive disc herniation is induced by an inflammatory response from the nucleus pulposus tissue and nerve roots. Lipoxins (LXs) are important endogenous anti-inflammatory mediators in the body, helping to inhibit neutrophil recruitment and stimulate autophagy in monocytes and macrophages. Here, we investigated the molecular mechanisms underlying the effects of exogenous lipoxin administration on rats with non-compressive disc herniation.

Method

A non-compressive disc herniation model was established in rats. Fifty rats were randomly divided into: sham group, model group, PI3K inhibitor (LY294002) group, lipoxin A4 group (LXA4), and PI3K inhibitor and lipoxin A4 group (LY294002 + LXA4). Similar groupings were established for rat spinal neurons. Changes in the mechanical pain threshold and thermal pain threshold were monitored at different times. The expression of proinflammatory and anti-inflammatory mediators was assessed by ELISA, while immunohistochemistry was employed to measure the expression levels of NLRP3 and p-JNK1. The expression levels of autophagy-related proteins were measured by western blot.

Results

In vivo, the pain threshold was markedly decreased in the model group at each time point examined compared with that in sham group. LY294002 treatment further reduced the pain threshold. After LXA4 injection, the pain threshold was significantly increased, and the effect of LY294002 was significantly weakened (p < 0.05). The levels of proinflammatory cytokines were increased in rats with non-compressive disc herniation, and these levels were further increased by LY294002 treatment (p < 0.05). However, treatment with LXA4 significantly reduced the levels of these proinflammatory cytokines in the model group (p < 0.05). The opposite effect was observed for anti-inflammatory mediators. The expression of NLRP3 was largely increased in the model group compared with that in the sham group (p < 0.05). Treatment with LY294002 also increased the NLRP3 expression level, while the administration of LXA4 elicited the opposite effect. Furthermore, western blot analysis showed that the expression of autophagy-related proteins was greatly decreased in the model group, whereas it was significantly increased in the LXA4 group (p < 0.05). The in vitro results were consistent with the outcomes observed in vivo.

Conclusions

These data suggested that LXA4 inhibited NLRP3 activation in rats with non-compressive disc herniation by regulating the JNK1/beclin-1/PI3KC3 pathway.

Benefits and adverse effects of hydroxychloroquine, methotrexate and colchicine: searching for repurposable drug candidates

Repurposing of antirheumatic drugs has garnered global attention. The aim of this article is to overview available evidence on the use of widely used antirheumatic drugs hydroxychloroquine, methotrexate and colchicine for additional indications. Hydroxychloroquine has endothelial stabilizing and anti-thrombotic effects. Its use has been explored as an adjunctive therapy in refractory thrombosis in antiphospholipid syndrome. It may also prevent recurrent pregnancy losses in the absence of antiphospholipid antibodies. Hydroxychloroquine favourably modulates atherogenic lipid and glycaemic profiles. Methotrexate has been tried for modulation of cardiovascular events in non-rheumatic clinical conditions, although a large clinical trial failed to demonstrate a benefit. Colchicine has been shown to successfully reduce the risk of recurrent cardiovascular events in a large multicentric trial. Potential antifibrotic effects of colchicine require further exploration. Hydroxychloroquine, methotrexate and colchicine are also being tried at different stages of the ongoing Coronavirus Disease 19 (COVID-19) pandemic for prophylaxis and treatment. While the use of these agents is being diversified, their adverse effects should be timely diagnosed and prevented. Hydroxychloroquine can cause retinopathy and rarely cardiac and auditory toxicity, retinopathy being dose and time dependent. Methotrexate can cause transaminitis, cytopenias and renal failure, particularly in acute overdoses. Colchicine can rarely cause myopathies, cardiomyopathy, cytopenias and transaminitis. Strong evidence is warranted to keep balance between benefits of repurposing these old antirheumatic drugs and risk of their adverse effects.

Inhibitory effects of phytochemicals on NLRP3 inflammasome activation: A review

BACKGROUND

The NLRP3 inflammasome formation and following cytokine secretion is a crucial step in innate immune responses. Internal and external factors may trigger inflammasome activation and result in inflammatory cytokine secretion. Inflammasome formation and activity play critical roles in several disease pathologies such as cardiovascular, metabolic, renal, digestive, and CNS diseases. Underlying pathways are not yet clear, but phytochemicals as alternative therapies have been extensively used for suppression of inflammatory responses.

PURPOSE

In this review, we aimed to summarize in vivo and in vitro effects on NLRP3 inflammasome activation of selected phytochemicals.

METHOD

Three phytochemicals; Sulforaphane, Curcumin, and Resveratrol were selected, and studies were reviewed to clarify their intracellular signaling mechanism in NLRP3 inflammasome activity. PubMed and Scopus databases are used for the search. For sulforaphane, 8 articles, for curcumin, 25 articles, and for resveratrol, 41 articles were included in the review.

CONCLUSION

In vitro and in vivo studies pointed out that the selected phytochemicals have inhibitory properties on NLRP3 inflammasome activity. However, neither the mechanism is clear, nor the study designs and doses are standardized.

Colchicine and myocardial infarction: A review

The inflammatory response is frequent after acute myocardial infarction, and may worsen ischaemia-reperfusion injuries, leading to increased infarct size and poor prognosis. Therefore, inflammation may be a promising therapeutic target, and anti-inflammatory drugs appear to be potential additional treatments in this context. Among these treatments, colchicine-a well-known drug that has been used for centuries in clinical practice for rheumatism-may represent the ideal candidate. Indeed, colchicine exerts direct anti-inflammatory and pleiotropic effects, with potential anti-arrhythmic, anti-fibrotic and anti-atherosclerotic effects, which are particularly interesting in this population of patients. The effects of colchicine in the context of acute myocardial infarction were first studied in preclinical models, with a decrease in inflammation demonstrated in several in vitro and in vivo models. Moreover, a decrease in infarct size and positive effects on haemodynamic variables were also recently demonstrated in a mouse model. Regarding clinical studies, the positive effect of colchicine in stable coronary disease and atherosclerosis was assessed initially. More recently, the value of colchicine in acute myocardial infarction has been studied, showing a positive effect on inflammation and infarct size reduction. Finally, a randomised trial (the COLCOT study) has shown a reduction in outcomes in patients with acute coronary syndrome treated with colchicine.

microRNA-9 Inhibits Vulnerable Plaque Formation and Vascular Remodeling via Suppression of the SDC2-Dependent FAK/ERK Signaling Pathway in Mice With Atherosclerosis

microRNAs (miRNAs or miRs) play important roles in modulating the occurrence and progression of atherosclerosis and acute coronary syndrome (ACS). Herein, this study aimed to investigate the possible role of miR-9 in the development of atherosclerosis. Initially, the differentially expressed genes associated with ACS were screened and miRNAs that regulate syndecan-2 (SDC2) were predicted using microarray analysis. Furthermore, the biological functions of miR-9 and SDC2 on aortic plaque area, proliferation of collagen fibers, Mac-3-labeled macrophages, inflammatory response, and levels of the focal adhesion kinase/extracellular signal-regulated kinase (FAK/ERK) signaling pathway-related proteins in atherosclerosis were evaluated after ectopic miR-9 expression or SDC2 depletion in ACS mice using oil red O staining, Masson’s trichrome staining, immunohistochemistry, and Western blot analysis, respectively. SDC2 was highly-expressed, while miR-9 was poorly-expressed in atherosclerosis. Additionally, miR-9 targeted SDC2 and negatively-regulated its expression. Up-regulation of miR-9 reduced aortic plaque area, the proliferation of collagen fibers, Mac-3-labeled macrophages and levels of IL-6, IL-1β, and TNF-α by suppressing SDC2 and the FAK/ERK signaling pathway, thereby ameliorating atherosclerosis in ACS mice. In conclusion, the current study provides evidence that miR-9 retards atherosclerosis by repressing SDC2 and the FAK/ERK signaling pathway, highlighting a new theoretical basis for the treatment of atherosclerosis.

Colchicine in Acute Coronary Syndrome: A Systematic Review

OBJECTIVE

The purpose of this review is to evaluate the efficacy and safety of colchicine after acute coronary syndrome (ACS).

DATA SOURCES

English-language searches were made of MEDLINE and EMBASE from database inception through mid-June 2020.

STUDY SELECTION AND DATA EXTRACTION

Randomized trials characterizing the effects of colchicine in ACS were considered. Of 627 title and abstracts identified, nine trials were included. Two reviewers extracted data and rated study quality.

DATA SYNTHESIS

Four studies showed colchicine did not attenuate C-reactive protein production. Colchicine did modulate the NOD-like receptor family pyrin domain containing 3 inflammasome in 3 studies and reduced production of chemokine ligand 2 (CCL2), CCL5, and C-X3-C motif chemokine ligand 1 in 1 study. Major adverse cardiovascular events (MACE) were not significantly different at 30 days in 3 studies, administered as 1.8 mg preprocedurally or scheduled 1 mg daily. One study found a significant reduction in MACE with colchicine 0.5 mg daily over median 22.6 months (hazard ratio = 0.77; 95% CI = 0.61-0.96). Colchicine is associated with increased gastrointestinal adverse events but was generally well tolerated.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Colchicine is likely to reduce MACE in an ACS population if administered for greater than 30 days but does not improve MACE when administered only preprocedurally.

CONCLUSIONS

Adjunctive colchicine 0.5 mg daily for greater than 30 days is reasonable for an ACS population on guideline-directed medical therapy treated with PCI. Additional studies are needed to validate and determine the durability of these benefits.

NLPR3 Inflammasomes and Their Significance for Atherosclerosis

Atherosclerosis is a serious disorder, with numerous potential complications such as cardiovascular disease, ischemic stroke, and myocardial infarction. The origin of atherosclerosis is related to chronic inflammation, lipid metabolism alterations, and oxidative stress. Inflammasomes are the cytoplasmic multiprotein complex triggering the activation of inflammatory response. NLRP3 inflammasomes have a specific activation pathway that involves numerous stimuli, including a wide range of PAMPs and DAMPs. Recent studies of atherosclerotic pathology are focused on the mitochondria that appear to be a promising target for therapeutic approach development. Mitochondria are the main source of reactive oxygen species (ROS) associated with oxidative stress. It was previously shown that NLRP3 inflammasome activation results in mitochondrial damage, but the exact mechanisms of this need to be specified. In this review, we focused on the features of NLRP3 inflammasomes and their significance for atherosclerosis, especially concerning mitochondria.

Colchicine for acute and chronic coronary syndromes

Colchicine is an ancient drug, traditionally used for the treatment and prevention of gouty attacks; it has become standard of treatment for pericarditis with a potential role in the treatment of coronary artery disease. Atherosclerotic plaque formation, progression, destabilisation and rupture are influenced by active proinflammatory cytokines interleukin (IL)-1β and IL-18 that are generated in the active forms by inflammasomes, which are cytosolic multiprotein oligomers of the innate immune system responsible for the activation of inflammatory responses. Colchicine has a unique anti-inflammatory mechanism: it is not only able to concentrate in leucocytes, especially neutrophils, and block tubulin polymerisation, affecting the microtubules assembly, but also inhibits (NOD)-like receptor protein 3 (NLRP3) inflammasome. On this basis, colchicine interferes with several functions of leucocytes and the assembly and activation of the inflammasome as well, reducing the production of interleukin 1β and interleukin 18. Long-term use of colchicine has been associated with a reduced rate of cardiovascular events both in chronic and acute coronary syndromes, with an overall good safety profile. This review will focus on the influence of colchicine on the pathophysiology of coronary artery disease, reviewing essential pharmacology and discussing the most important and recent clinical studies. On the basis of current literature, colchicine is emerging as a possible new valuable, safe and cheap agent for the treatment of acute and chronic coronary syndromes.

Treatments for COVID-19: emerging drugs against the coronavirus

The Coronavirus disease 19 (COVID-19) outbreak has been recognized as a global threat to public health. It is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and no effective therapies currently exist against this novel viral agent. Along with extensive public health measures, an unprecedented global effort in identifying effective drugs for the treatment is being implemented. Potential drug targets are emerging as the result of a fast-evolving understanding of SARS-CoV-2 virology, host response to the infection, and clinical course of the disease. This brief review focuses on the latest and most promising pharmacological treatments against COVID-19 currently under investigation and discuss their potential use based on either documented efficacy in similar viral infections, or their activity against inflammatory syndromes. Ongoing clinical trials are also emphasized.

Colchicine for Secondary Cardiovascular Prevention: A Systematic Review

Despite advancements in medical and interventional therapy, patients with cardiovascular disease (CVD) continue to have residual risk for recurrent cardiovascular events. Colchicine has a unique antiinflammatory mechanism that has generated interest in its potential use as a secondary cardiovascular preventive therapy. The objective of this systematic review was to evaluate the evidence for long-term (6 months or more) colchicine therapy in patients with established CVD. A search of Medline and Embase from inception to February 2020 was performed. Included were randomized controlled trials (RCTs) or propensity score-matched observational studies that compared colchicine (at any dose) with placebo or no treatment. Outcomes of interest included any major adverse cardiovascular event, cardiovascular hospitalization, coronary artery restenosis, cardiovascular death, or all-cause death. Five RCTs were included. The dose of colchicine ranged from 0.5 mg/day to 0.6 mg twice/day, and follow-up ranged from ~6-36 months. Two trials (one double blind and one single blind) showed a reduction in composite outcomes of major adverse cardiovascular events. One study failed to demonstrate a benefit with colchicine in restenosis or recurrent ischemia after angioplasty; however, it was conducted before the routine use of modern percutaneous coronary intervention and medical therapies. In contrast, a more recent trial found that colchicine reduced the rate of in-stent restenosis in patients who received a bare metal stent. Finally, one trial in patients with heart failure with reduced ejection fraction did not observe a benefit in death or heart failure hospitalization with colchicine despite a reduction in inflammatory markers. No trial demonstrated a reduction in cardiovascular or all-cause death, and most trials showed an increase in the rate of diarrhea with colchicine. Overall, colchicine has demonstrated promising results for the secondary prevention of CVD; however, further studies are required to confirm these findings before colchicine can be routinely recommended in practice.

Electrical stimulation inhibits Val-boroPro-induced pyroptosis in THP-1 macrophages via sirtuin3 activation to promote autophagy and inhibit ROS generation

The incidence of atherosclerosis (AS), a major contributor to cardiovascular disease, is steadily rising along with an increasingly older population worldwide. Pyroptosis, a form of inflammatory programmed cell death, determines the release of pro-inflammatory mediators by endothelial cells, smooth muscle cells, and atheroma-associated macrophages and foam cells, thereby playing a critical role in AS progression. Canonical pyroptosis is mediated by inflammasome formation, activation of caspase-1, and maturation and release of proinflammatory cytokines. Electrical stimulation (ES) is a noninvasive, safe therapy that has been shown to alleviate symptoms in several health conditions. Here, we investigated the anti-inflammatory and anti-pyroptotic effects of ES in human THP-1 macrophages treated with the dipeptidyl peptidase inhibitor Val-boroPro (VbP). We found that ES downregulated NOD-like receptor family protein 3 (NLRP3) inflammasome, ASC, and caspase-1 expression and abrogated the release of Interleukin-1β (IL-1β) and Interleukin-18 (IL-18), indicating effective pyroptosis inhibition. These changes were paralleled by a reduction in reactive oxygen species (ROS) production, reversal of VbP-induced sirtuin3 (Sirt3) downregulation, deacetylation of ATG5, and induction of autophagy. These findings suggest that ES may be a viable strategy to counteract pyroptosis-mediated inflammation in AS by raising Sirt3 to promote autophagy and inhibit ROS generation.

NLRP3 Inflammasome: A Potential Alternative Therapy Target for Atherosclerosis

Atherosclerosis (AS) is a complex and chronic inflammatory disease that occurs in multiple systems of the human body. It is an important pathological basis for a variety of diseases and a serious threat to human health. So far, many theories have been formed to explain the pathogenesis of atherosclerosis, among which “inflammation theory” has gradually become a research focus. This theory presents that inflammatory response runs through the whole progress of AS, inflammatory cells play as the main executors of AS, and inflammatory mediators are the key molecules of AS. In the inflammatory process of atherosclerosis, the role of NLRP3 in the atherosclerosis has gradually got the attention of researchers. NLRP3 is a kind of signal-transductional pattern recognition receptors (PRRs). After recognizing and binding to the damage factors, NLRP3 inflammasome will be assembled to activate IL-1β and caspase-1 pathways, resulting in promoting the inflammation process of AS, reducing the stability of the plaques, and finally increasing the incidence of adverse cardiovascular events. Taken above, the article will review the potential benefits of drugs targeting the NLRP3 inflammasome in the therapy of AS.

New evidence on the role of inflammation in CVD risk

PURPOSE OF REVIEW

Based on compelling data from animal and human studies, over the past few decades, the viewpoint of atherosclerosis as an exclusively lipid-driven disease, has been gradually replaced by the concept of a chronic low-grade inflammatory process of the arterial wall. This review presents a brief description on the role of inflammation in atherosclerosis, and examines selected anti-inflammatory interventions that have been tested in clinical trials designed to prevent adverse cardiovascular disease (CVD) events and excess CVD risk.

RECENT FINDINGS

The Canakinumab Anti-inflammatory Thrombosis Outcomes Study trial has provided convincing evidence that neutralization of the interleukin (IL)-1β inflammatory pathway by the selective antibody canakinumab reduces major CVD events and significantly lowers IL-1β, IL-6 and high-sensitivity C-reactive protein, without affecting low-density lipoprotein cholesterol levels. In contrast, in the latest Cardiovascular Inflammation Reduction Trial, low-dose methotrexate compared with placebo did not reduce CVD events, probably because there was no reduction in IL-1β, or in downstream inflammatory biomarker levels either.

SUMMARY

Notwithstanding the utilization of effective medical treatments including statins and proprotein convertase subtilisin/kexin type 9 inhibitors or precise revascularizations, the recurrence of CVD events remains unacceptably high. Canakinumab is, at present, the only anti-inflammatory agent that has been proven to reduce cardiovascular events in patients with elevated markers of inflammation without modifying cholesterol levels. Nevertheless, clinical application related to this new evidence and associated knowledge has not yet been implemented in daily practice.

Effects of Colchicine on Atherosclerotic Plaque Stabilization: a Multimodality Imaging Study in an Animal Model

Colchicine demonstrated clinical benefits in the treatment of stable coronary artery disease. Our aim was to evaluate the effects of colchicine on atherosclerotic plaque stabilization. Atherosclerosis was induced in the abdominal aorta of 20 rabbits with high-cholesterol diet and balloon endothelial denudation. Rabbits were randomized to receive either colchicine or placebo. All animals underwent MRI, ¹⁸F-FDG PET/CT, optical coherence tomography (OCT), and histology. Similar progression of atherosclerotic burden was observed in the two groups as relative increase of normalized wall index (NWI). Maximum ¹⁸F-FDG standardized uptake value (meanSUVmax) decreased after colchicine treatment, while it increased in the placebo group with a trend toward significance. Animals with higher levels of cholesterol showed significant differences in favor to colchicine group, both as NWI at the end of the protocol and as relative increase in meanSUVmax. Colchicine may stabilize atherosclerotic plaque by reducing inflammatory activity and plaque burden, without altering macrophage infiltration or plaque typology.

Atherosclerosis: Insights into Vascular Pathobiology and Outlook to Novel Treatments

The pathobiology of atherosclerosis and its current and potential future treatments are summarized, with a spotlight on three central cell types involved: (i) endothelial cells (ECs), (ii) macrophages, and (iii) vascular smooth muscle cells (VSMCs). (i) EC behaviour is regulated by the central transcription factors YAP/TAZ in reaction to biomechanical forces, such as hemodynamic shear stress. (ii) VSMC transdifferentiation (phenotype switching) to a macrophage-like phenotype contributes to the majority of cells positive for common cell surface macrophage markers in atherosclerotic plaques. (iii) Intra-plaque macrophages originate in a significant number from vascular resident macrophages. They can be activated via pattern recognition receptors on cell membrane (e.g. toll-like receptors) and inside cells (e.g. inflammasomes), requiring priming by neutrophil extracellular traps (NETs). ECs and macrophages can also be characterized by single-cell RNA sequencing. Adaptive immunity plays an important role in the inflammatory process. Future therapeutic options include vaccination, TRAF-STOPs, senolysis, or CD47 blockade. Graphical Abstract.

The role of inflammasomes in kidney disease

Inflammasomes are multiprotein innate immune complexes that regulate caspase-dependent inflammation and cell death. Pattern recognition receptors, such as nucleotide-binding oligomerization domain (NOD)-like receptors and absent in melanoma 2 (AIM2)-like receptors, sense danger signals or cellular events to activate canonical inflammasomes, resulting in caspase 1 activation, pyroptosis and the secretion of IL-1β and IL-18. Non-canonical inflammasomes can be activated by intracellular lipopolysaccharides, toxins and some cell signalling pathways. These inflammasomes regulate the activation of alternative caspases (caspase 4, caspase 5, caspase 11 and caspase 8) that lead to pyroptosis, apoptosis and the regulation of other cellular pathways. Many inflammasome-related genes and proteins have been implicated in animal models of kidney disease. In particular, the NLRP3 (NOD-, LRR- and pyrin domain-containing 3) inflammasome has been shown to contribute to a wide range of acute and chronic microbial and non-microbial kidney diseases via canonical and non-canonical mechanisms that regulate inflammation, pyroptosis, apoptosis and fibrosis. In patients with chronic kidney disease, immunomodulation therapies targeting IL-1β such as canakinumab have been shown to prevent cardiovascular events. Moreover, findings in experimental models of kidney disease suggest that small-molecule inhibitors targeting NLRP3 and other inflammasome components are promising therapeutic agents.

Lysophosphatidylcholine Induces NLRP3 Inflammasome-Mediated Foam Cell Formation and Pyroptosis in Human Monocytes and Endothelial Cells

Foam cells are specialized lipid-loaded macrophages derived from monocytes and are a key pathological feature of atherosclerotic lesions. Lysophosphatidylcholine (LPC) is a major lipid component of the plasma membrane with a broad spectrum of proinflammatory activities and plays a key role in atherosclerosis. However, the role of LPC in lipid droplet (LD) biogenesis and the modulation of inflammasome activation is still poorly understood. In the present study, we investigated whether LPC can induce foam cell formation through an analysis of LD biogenesis and determined whether the cell signaling involved in this process is mediated by the inflammasome activation pathway in human endothelial cells and monocytes. Our results showed that LPC induced foam cell formation in both types of cells by increasing LD biogenesis via a NLRP3 inflammasome-dependent pathway. Furthermore, LPC induced pyroptosis in both cells and the activation of the inflammasome with IL-1β secretion, which was dependent on potassium efflux and lysosomal damage in human monocytes. The present study described the IL-1β secretion and foam cell formation triggered by LPC via an inflammasome-mediated pathway in human monocytes and endothelial cells. Our results will help improve our understanding of the relationships among LPC, LD biogenesis, and NLRP3 inflammasome activation in the pathogenesis of atherosclerosis.

Colchicine-Binding Site Inhibitors from Chemistry to Clinic: A Review

It is over 50 years since the discovery of microtubules, and they have become one of the most important drug targets for anti-cancer therapies. Microtubules are predominantly composed of the protein tubulin, which contains a number of different binding sites for small-molecule drugs. There is continued interest in drug development for compounds targeting the colchicine-binding site of tubulin, termed colchicine-binding site inhibitors (CBSIs). This review highlights CBSIs discovered through diverse sources: from natural compounds, rational design, serendipitously and via high-throughput screening. We provide an update on CBSIs reported in the past three years and discuss the clinical status of CBSIs. It is likely that efforts will continue to develop CBSIs for a diverse set of cancers, and this review provides a timely update on recent developments.

[Kidney disease care for the elderly]

In our aging population, kidney disease management needs to take into account the frailty of the elderly. Standardized geriatric assessments can be proposed to help clinicians apprehend this dimension in their daily practice. These tools allow to better identify frail patients and offer them more personalized and harmless treatments. This article aims to focus on the kidney diseases commonly observed in elderly patients and analyze their specific nephrogeriatric care modalities. It should be noticed that all known kidney diseases can be also observed in the elderly, most often with a quite similar clinical presentation. This review is thus focused on the diseases most frequently and most specifically observed in elderly patients (except for monoclonal gammopathy associated nephropathies, out of the scope of this work), as well as the peculiarities of old age nephrological care.

ER Stress Activates the NLRP3 Inflammasome: A Novel Mechanism of Atherosclerosis

The endoplasmic reticulum (ER) is an important organelle that regulates several fundamental cellular processes, and ER dysfunction has implications for many intracellular events. The nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome is an intracellularly produced macromolecular complex that can trigger pyroptosis and inflammation, and its activation is induced by a variety of signals. ER stress has been found to affect NLRP3 inflammasome activation through multiple effects including the unfolded protein response (UPR), calcium or lipid metabolism, and reactive oxygen species (ROS) generation. Intriguingly, the role of ER stress in inflammasome activation has not attracted a great deal of attention. In addition, increasing evidence highlights that both ER stress and NLRP3 inflammasome activation contribute to atherosclerosis (AS). AS is a common cardiovascular disease with complex pathogenesis, and the precise mechanisms behind its pathogenesis remain to be determined. Both ER stress and the NLRP3 inflammasome have emerged as critical individual contributors of AS, and owing to the multiple associations between these two events, we speculate that they contribute to the mechanisms of pathogenesis in AS. In this review, we aim to summarize the molecular mechanisms of ER stress, NLRP3 inflammasome activation, and the cross talk between these two pathways in AS in the hopes of providing new pharmacological targets for AS treatment.

NLRP3 Inflammasome: A Novel Player in Metabolically Induced Inflammation-Potential Influence on the Myocardium

Metabolic and immune systems are among the most fundamental requirements for survival. Many metabolic and immune response pathways or nutrient- and pathogen-sensing systems are evolutionarily conserved throughout species. As a result, the immune response and metabolic regulation are highly integrated and the proper function of each is dependent on the other. This interaction between metabolic disturbances and the immune system has been most extensively studied in disorders related to obesity such as insulin resistance, type 2 diabetes, and nonalcoholic fatty liver disease. Metabolically induced inflammation seems also to play a role in the development and progression of atherosclerosis including its complications such as myocardial infarction (MI) and post-MI remodeling. There are several lines of evidence suggesting that NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome is a sensor of metabolic stress linking metabolic disturbances to inflammation. Here, we will discuss the role of the NLRP3 inflammasome in the pathogenesis of obesity and diabetes, 2 important risk factors for atherosclerosis and MI. We will also discuss the role of NLRP3 inflammasome in the interaction between metabolic disturbances and myocardial inflammation during MI and during metabolically induced myocardial remodeling.

The association between hyperuricemia and coronary artery calcification development: A systematic review and meta-analysis

Hyperuricemia coincides with coronary artery calcification (CAC) development, but the role of serum uric acid (SUA) as a risk factor for CAC remains unclear. The objective of this study was to gain an insight into the association between SUA and CAC in adults by performing a meta-analysis. MEDLINE, EMBASE, the Cochrane Library, and EBSCO (CINAHL) were searched for relevant observational studies published until 2 June 2019. Studies were included only if they reported data on CAC presence (Agatston score > 0) or progression related to hyperuricemia in subclinical adult patients. The pooled estimates of crude and adjusted odds ratios (ORs) and 95% confidence interval (CI) were calculated to evaluate the association between CAC presence or progression and hyperuricemia. A total of 11 studies were identified involving 11 108 adults. The pooled OR based on the frequency of CAC presence showed that patients in the high SUA group had 1.806-fold risk for developing CAC (95% CI: 1.491-2.186) under the minimal threshold of hyperuricemia (more than 6 mg/dL or 357 μmoL/L). When SUA levels were analyzed as categorical variables, the pooled estimate of adjusted ORs was 1.48 (95% CI: 1.23-1.79) for CAC presence. Additionally, for each increase of 1 mg/dL of SUA level, the risk of CAC progression was increased by 31% (95% CI: 1.15-1.49) with an average follow-up duration ranged from 4.6 to 6.1 years. Hyperuricemia is closely associated with increased risk of CAC development and CAC progression in asymptomatic patients.

Macrophages and T cells in atherosclerosis: a translational perspective

Atherosclerosis is now considered a chronic maladaptive inflammatory disease. The hallmark feature in both human and murine disease is atherosclerotic plaques. Macrophages and various T-cell lineages play a crucial role in atherosclerotic plaque establishment and disease progression. Humans and mice share many of the same processes that occur within atherogenesis. The various similarities enable considerable insight into disease mechanisms and those which contribute to cardiovascular complications. The apolipoprotein E-null and low-density lipoprotein receptor-null mice have served as the foundation for further immunological pathway manipulation to identify pro- and antiatherogenic pathways in attempt to reveal more novel therapeutic targets. In this review, we provide a translational perspective and discuss the roles of macrophages and various T-cell lineages in contrasting proatherosclerotic and atheroprotective settings.

Cholesterol-embolization syndrome: current perspectives

Cholesterol-embolization syndrome (CES) is a multisystemic disease with various clinical manifestations. CES is caused by embolization of cholesterol crystals (CCs) from atherosclerotic plaques located in the major arteries, and is induced mostly iatrogenically by interventional and surgical procedures; however, it may also occur spontaneously. Embolized CCs lead to both ischemic and inflammatory damage to the target organ. Therefore, anti-inflammatory agents, such as corticosteroids and cyclophosphamide, have been investigated as treatment for CES in several studies, with conflicting results. Recent research has revealed that CES is actually a kind of autoinflammatory disease in which inflammasome pathways, such as NLRP3 and IL1, are induced by CCs. These recent findings may have clinical implications such that colchicine and IL1 inhibitors, namely canakinumab, may be beneficial in the early stages of CES.

Targeting Early Atherosclerosis: A Focus on Oxidative Stress and Inflammation

Atherosclerosis is a chronic vascular inflammatory disease associated to oxidative stress and endothelial dysfunction. Oxidation of low-density lipoprotein (LDL) cholesterol is one of the key factors for the development of atherosclerosis. Nonoxidized LDL have a low affinity for macrophages, so they are not themselves a risk factor. However, lowering LDL levels is a common clinical practice to reduce oxidation and the risk of major events in patients with cardiovascular diseases (CVD). Atherosclerosis starts with dysfunctional changes in the endothelium induced by disturbed shear stress which can lead to endothelial and platelet activation, adhesion of monocytes on the activated endothelium, and differentiation into proinflammatory macrophages, which increase the uptake of oxidized LDL (oxLDL) and turn into foam cells, exacerbating the inflammatory signalling. The atherosclerotic process is accelerated by a myriad of factors, such as the release of inflammatory chemokines and cytokines, the generation of reactive oxygen species (ROS), growth factors, and the proliferation of vascular smooth muscle cells. Inflammation and immunity are key factors for the development and complications of atherosclerosis, and therefore, the whole atherosclerotic process is a target for diagnosis and treatment. In this review, we focus on early stages of the disease and we address both biomarkers and therapeutic approaches currently available and under research.

hsCRP Level and the Risk of Death or Recurrent Cardiovascular Events in Patients With Myocardial Infarction: a Healthcare-Based Study

Background

Beyond the controlled setting of trials, scarce information exists on the burden, predictors, and outcomes associated with elevated hsCRP (high‐sensitivity C‐reactive protein) in “real‐world” patients with myocardial infarction (MI).

Methods and Results

We included all‐coming MI survivors undergoing hsCRP testing >30 days after an MI during routine health care in Stockholm, Sweden (2006–2011). hsCRP tests measured during hospitalization/emergency department visits, followed by antibiotics or indicative of acute illness, were excluded, together with patients with ongoing/recent cancer, chronic infections, or immunosuppression. Inflammation was defined over a 3‐month baseline window and associated with subsequent death and major adverse cardiovascular events (composite of MI, ischemic stroke, or cardiovascular death). Included were 17 464 patients (63% men; mean age, 72.6 years) with a median hsCRP level of 2.2 (interquartile range, 1.0–6.0) mg/L and a median of 2.2 (interquartile range, 0.8–4.9) years since their MI. Most (66%) had hsCRP ≥2 mg/L, and 40% had hsCRP >3 mg/L. Lower hemoglobin, lower estimated glomerular filtration rate, and comorbidities (eg, heart failure, peripheral vascular disease, stroke, atrial fibrillation, diabetes mellitus, and rheumatoid diseases) were associated with higher odds of hsCRP ≥2 mg/L. Conversely, previous percutaneous coronary intervention, ongoing renin‐angiotensin blockade, and statins were associated with lower hsCRP ≥2 mg/L odds. Patients with hsCRP ≥2 mg/L were at higher risk of major adverse cardiovascular events (n=3900; adjusted hazard ratio, 1.28; 95% CI, 1.18–1.38) and death (n=4138; adjusted hazard ratio, 1.42; 95% CI, 1.31–1.53). Results were robust across subgroups of patients and after exclusion of events occurring during the first 6 to 12 months. On a continuous scale, the association between hsCRP and outcomes was linear until hsCRP >5 mg/L, plateauing thereafter.

Conclusions

Most patients with MI exhibit elevated hsCRP levels. Besides identifying populations at high‐inflammatory risk, this study extends the prognostic validity of this biomarker from trial evidence to real‐world healthcare settings.

Pulegone inhibits inflammation via suppression of NLRP3 inflammasome and reducing cytokine production in mice

Context: Pulegone, a key compound in Schizonepeta essential oil, has been identified as an anti-inflammatory. However, its underlying molecular mechanisms on NLR family pyrin domain containing 3 (NLRP3) inflammasome have not been elucidated. Objective: Here, the modulatory effects of pulegone on NLRP3 inflammasome were investigated. Materials and methods: The C57BL/6J mice were randomly divided into five groups: Normal, Lipopolysaccharides (LPS), Dexamethasone (DEX, 5 mg/kg), Pulegone (0.095 and 0.190 g/kg) groups. All mice were challenged by LPS except for the Normal group. Results: A reduced expression of Interleukin-18 (IL-18), Interleukin-1β (IL-1β), Interleukin-5 (IL-5), Tumor necrosis factor-α (TNF-α), Interferon-gamma (IFN-γ), Monocyte chemoattratctant protein-1 (MCP-1), Macrophage inflammatory protein-1β (MIP-1β), Monocyte colony stimulating factor (M-CSF) and Granulocyte-macrophage colony stimulating factor (GM-CSF) in serum were detected in the pulegone groups as compared to the LPS group. In addition, a reduced mRNA and protein expression production of ASC, NLRP3, and Caspase-1 were detected in lungs after pulegone administration. Histological analysis results indicated that the histological changes of lungs caused by LPS were ameliorated by pulegone. Immunohistochemical study showed a decreased positive cell numbers of P2X7R in Pulegone (0.095 and 0.190 g/kg) groups. Conclusion: Pulegone exerts anti-inflammatory effects on LPS-induced sepsis mice via inhibition of the NLRP3 expression.

Colchicine: An Impressive Effect on Posttransplant Capillary Leak Syndrome and Renal Failure

Capillary leak syndrome is a critical condition occasionally occurring posttransplant and is characterized by acute endothelial hyperpermeability leading to systemic protein-rich fluid extravasation and consequent hypovolemia, hypoperfusion, and acute kidney injury. Treatment is merely supportive and is based on osmotic drugs, diuretics, continuous renal replacement therapy, and surgical drainage. However, removal of the underlying inflammatory cause is mandatory to achieve stable resolution. Herein, we report the first successful treatment with colchicine in 2 life-threatening pediatric cases of capillary leak syndrome with renal failure occurring after transplant (heart and bone marrow) and unresponsive to any other line of therapy. Both cases were only palliated by supportive therapy and revealed an impressively rapid response to colchicine both in terms of diuresis and clinical condition recovery, allowing for the cessation of renal replacement therapy in a few hours. In both patients, colchicine was temporarily discontinued for transient leukopenia (attributed to an additive effect with mycophenolate mofetil), resulting in extravasation, and renal failure recurrence was restored only after colchicine reintroduction. Although the association of colchicine with an immunosuppressive drug was formerly contraindicated, no other adverse events were noted when using a minimized dose. Both patients are now maintaining a good renal function without recurrence of extravasation after 6 months of follow-up. In conclusion, this strikingly positive experience forces physicians to consider this old and cost-effective drug as a new, powerful rescue tool in such critical cases.