Plasma S100A8/A9 Correlates With Blood Neutrophil Counts, Traditional Risk Factors, and Cardiovascular Disease in Middle-Aged Healthy Individuals

Short-term S100A8/A9 Blockade Promotes Cardiac Neovascularization after Myocardial Infarction

Acute-phase inhibition of the pro-inflammatory alarmin S100A8/A9 improves cardiac function post-myocardial infarction (MI), but the mechanisms underlying the long-term benefits of this short-term treatment remain to be elucidated. Here, we assessed the effects of S100A8/A9 blockade with the small-molecule inhibitor ABR-238901 on myocardial neovascularization in mice with induced MI. The treatment significantly reduced S100A9 and increased neovascularization in the myocardium, assessed by CD31 staining. Proteomic analysis by mass-spectrometry showed strong myocardial upregulation of the pro-angiogenic proteins filamin A (~ 10-fold) and reticulon 4 (~ 5-fold), and downregulation of the anti-angiogenic proteins Ras homolog gene family member A (RhoA, ~ 4.7-fold), neutrophilic granule protein (Ngp, ~ 4.0-fold), and cathelicidin antimicrobial peptide (Camp, ~ 4.4-fold) versus controls. In-vitro, ABR-238901 protected against apoptosis induced by recombinant human S100A8/A9 in human umbilical vein endothelial cells (HUVECs). In conclusion, S100A8/A9 blockade promotes post-MI myocardial neovascularization by favorably modulating pro-angiogenic proteins in the myocardium and by inhibiting endothelial cell apoptosis.

Circulating Levels of Calprotectin as a Biomarker in Patients With Coronary Artery Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Calprotectin, also known as MRP8/14, is generated by immune cells and is altered in several inflammatory diseases. Studies have assessed their levels in patients with coronary artery disease (CAD) and its subtypes (stable CAD and acute coronary syndrome [ACS]). Herein, we aimed to systematically investigate these associations through a systematic review and meta-analysis.

METHODS

A systematic search was conducted in four online databases, including PubMed, Scopus, Embase, and the Web of Science. Relevant studies were retrieved, screened, and extracted. Random-effect meta-analysis was performed for the calculation of standardized mean difference (SMD) and 95% confidence interval (CI). Blood calprotectin levels were compared between CAD patients and controls, as well as CAD subtypes.

RESULTS

A total of 20 studies were included in the systematic review and meta-analysis, comprising 3300 CAD patients and 1230 controls. Patients with CAD had significantly higher calprotectin levels (SMD 0.81, 95% CI 0.32-1.30, p < 0.01). Similarly, patients with ACS were reported to have higher levels compared to those with stable CAD. However, there was no significant difference in terms of blood calprotectin levels between stable CAD cases and healthy controls. Finally, studies have shown that calprotectin could be used as a diagnostic biomarker of CAD while also predicting major adverse events and mortality in these patients.

CONCLUSION

Based on our findings, calprotectin, as an inflammatory marker, could be used as a possible biomarker for patients with CAD and ACS. These suggest the possibility of pathophysiological pathways for this involvement and warrant further research on these associations as well as their clinical utility.

Releasing Dynamic of Serum ST2 and Calprotectin in Patients with Acute Ischemic Stroke

This study investigated the releasing dynamics of serum ST2 and calprotectin in patients with acute IS. The study included acute IS patients (N = 20) with an NIH Stroke Scale score ≥8. Sampling was performed at seven time points: after admission (T0) and at the following 24 h consecutive intervals (T1-T6). Primary outcome at 90 days was evaluated using the modified Rankin scale: 0-2 for good and 3-6 for poor functional outcome. The secondary outcome was all-cause mortality after 90 days. Fifteen patients had a poor outcome, and eight died. Results showed a statistically significant difference in ST2 concentrations between good and poor outcomes at T0 (p = 0.04), T1 (p = 0.006), T2 (p = 0.01), T3 (p = 0.021), T4 (p = 0.007), T5 (p = 0.032), and for calprotectin T6 (p = 0.034). Prognostic accuracy was highest for ST2 at T1 for a cut-off > 18.9 µg/L (sensitivity 80% and specificity 100.0%) and for calprotectin at T5 for a cut-off > 4.5 mg/L (sensitivity 64.3% and specificity 100.0%). Serum ST2 and calprotectin-releasing dynamics showed a valuable prognostic accuracy for IS outcomes.

S100a8/9 (S100 Calcium Binding Protein a8/9) Promotes Cardiac Hypertrophy Via Upregulation of FGF23 (Fibroblast Growth Factor 23) in Mice

BACKGROUND

S100a8/9 (S100 calcium binding protein a8/9) belongs to the S100 family and has gained a lot of interest as a critical regulator of inflammatory response. Our previous study found that S100a8/9 homolog promoted aortic valve sclerosis in mice with chronic kidney disease. However, the role of S100a8/9 in pressure overload-induced cardiac hypertrophy remains unclear. The present study was to explore the role of S100a8/9 in cardiac hypertrophy.

METHODS AND RESULTS

Cardiomyocyte-specific S100a9 loss or gain of function was achieved using an adeno-associated virus system, and the model of cardiac hypertrophy was established by aortic banding-induced pressure overload. The results indicate that S100a8/9 expression was increased in response to pressure overload. S100a9 deficiency alleviated pressure overload-induced hypertrophic response, whereas S100a9 overexpression accelerated cardiac hypertrophy. S100a9-overexpressed mice showed increased FGF23 (fibroblast growth factor 23) expression in the hearts after exposure to pressure overload, which activated calcineurin/NFAT (nuclear factor of activated T cells) signaling in cardiac myocytes and thus promoted hypertrophic response. A specific antibody that blocks FGFR4 (FGF receptor 4) largely abolished the prohypertrophic response of S100a9 in mice.

CONCLUSIONS

In conclusion, S100a8/9 promoted the development of cardiac hypertrophy in mice. Targeting S100a8/9 may be a promising therapeutic approach to treat cardiac hypertrophy.

A Prospective Study of the Association Between Plasma Calprotectin Levels and New-Onset CKD in the General Population

Introduction

Systemic inflammation has been associated with chronic kidney disease (CKD). In this study, we aimed to investigate a potential association between the plasma biomarker of inflammation calprotectin and new-onset CKD in a population-based cohort study.

Methods

Individuals without CKD at baseline (n = 4662) who participated in the Prevention of REnal and Vascular ENd-stage Disease (PREVEND) prospective population-based cohort study in the Netherlands were included. Baseline plasma calprotectin levels were assessed in samples that had been stored at -80 °C. Occurrence of new-onset CKD was defined as a composite outcome of an estimated glomerular filtration rate (eGFR) <60 ml/min per 1.73 m2, urinary albumin excretion (UAE) >30 mg/24h, or both.

Results

Baseline median (interquartile range) plasma calprotectin levels were 0.49 (0.35-0.68) mg/l and baseline median eGFR was 95.9 (interquartile range: 85.0-105.7) ml/min per 1.73 m2. After median follow-up of 8.3 (7.8-8.9) years, 467 participants developed new-onset CKD. Baseline plasma calprotectin levels were significantly associated with an increased risk of new-onset CKD (hazard ratio [HR] per doubling 1.28 [95% confidence interval, CI: 1.14-1.44], P < 0.001), independent of potentially confounding factors (HR 1.14 [95% CI: 1.01-1.29], P = 0.034), except for baseline high-sensitive C-reactive protein (hs-CRP) (HR 1.05 [0.91-1.21], P = 0.494). In secondary analyses, the association between plasma calprotectin and occurrence of UAE >30 mg/24h remained significant (HR 1.17 [1.02-1.34], P = 0.027), but not significantly so for the incidence of eGFR <60 ml/min per 1.73 m2 as individual outcome (HR 1.15 [0.92-1.43], P = 0.218).

Conclusion

Higher plasma calprotectin levels are associated with an increased risk of developing CKD in the general population. This association is mitigated after adjustment for hs-CRP, and more pronounced with new-onset CKD defined by UAE.

Biomarkers to monitor the prognosis, disease severity, and treatment efficacy in coronary artery disease

INTRODUCTION

Coronary Artery Disease (CAD) is a prevalent condition characterized by the presence of atherosclerotic plaques in the coronary arteries of the heart. The global burden of CAD has increased significantly over the years, resulting in millions of deaths annually and making it the leading health-care expenditure and cause of mortality in developed countries. The lack of cost-effective strategies for monitoring the prognosis of CAD warrants a pressing need for accurate and efficient markers to assess disease severity and progression for both reducing health-care costs and improving patient outcomes.

AREA COVERED

To effectively monitor CAD, prognostic biomarkers and imaging techniques play a vital role in risk-stratified patients during acute treatment and over time. However, with over 1,000 potential markers of interest, it is crucial to identify the key markers with substantial utility in monitoring CAD progression and evaluating therapeutic interventions. This review focuses on identifying and highlighting the most relevant markers for monitoring CAD prognosis and disease severity. We searched for relevant literature using PubMed and Google Scholar.

EXPERT OPINION

By utilizing the markers discussed, health-care providers can improve patient care, optimize treatment plans, and ultimately reduce health-care costs associated with CAD management.

Long COVID (PASC) Is Maintained by a Self-Sustaining Pro-Inflammatory TLR4/RAGE-Loop of S100A8/A9 > TLR4/RAGE Signalling, Inducing Chronic Expression of IL-1b, IL-6 and TNFa: Anti-Inflammatory Ezrin Peptides as Potential Therapy

Long COVID, also referred to as Post-Acute Sequelae of COVID (PASC), is probably triggered during SARS-CoV-2 infection and acute COVID-19 by SARS-CoV-2 Spike-protein binding and hyper-activating the cell-membrane expressed Receptor for Advance Glycation End-products (mRAGE) and Toll-Like Receptor 4 (TLR4). SARS-CoV-2 infects lung monocytes by Spike binding to mRAGE (not ACE2). During acute COVID-19, high levels of IL-6 hyper-stimulate S100A8/A9 expression and secretion. Although no viral protein nor mRNA can be detected in half of long COVID (PASC) patients, there is a significant elevation of serum levels of IL-1b, IL-6, TNFa, and S100A8/A9. It appears that a pathological pro-inflammatory feedback loop (the TLR4/RAGE-loop) is established during acute COVID-19, which is maintained by S100A8/A9 > RAGE/TLR4 chronic inflammatory signalling, even after SARS-CoV-2 has been cleared from the body. During long COVID/PASC, Ca2+-binding protein S100A8/A9 chronically stimulates TLR4/RAGE-signalling to induce chronic expression of IL-1b, IL-6 and TNFa. Secreted IL-6 binds to its IL-6R receptor on the surface of other cells and signals via STAT3 and C/EBPb for more S100A8/A9 expression. Secreted IL-1b binds to its receptor IL-1R on other cells, and signals via NFkB for more mRAGE and TLR4 expression. New S100A8/A9 can bind and activate cell-surface mRAGE and TLR4 to stimulate expression of more IL-1b, IL-6 and TNFa. This process establishes a pathogenic pro-inflammatory TLR4/RAGE-loop: IL-1b + IL-6 > IL-1R + IL-6R > TLR4/mRAGE + S100A8/A9 > IL-1b + IL-6, which generates multi-organ inflammation that persists in the blood vessels, the brain, the liver, the heart, the kidneys, the gut and the musculo-skeletal system, and is responsible for all the complex pathologies associated with long COVID/PASC. Chronic expression of IL-1, IL-6 and TNFa is critical for the maintenance of the TLR4/RAGE-loop and persistence of long COVID/PASC. Ezrin peptides are inhibitors of IL-1, IL-6, IL-8 and TNFa expression, so are now being investigated as potential therapy for long COVID/PASC. There is preliminary anecdotal evidence of symptomatic relief (not confirmed yet by formal clinical trials) from a few long COVID/PASC patient volunteers, after treatment with ezrin peptide therapy.

Association of S100A8/A9 with lipid-rich necrotic core and treatment with biologic therapy in patients with psoriasis: results from an observational cohort study

Psoriasis is a systemic inflammatory disease with increased risk of atherosclerotic events and premature cardiovascular disease. S100A7, A8/A9, and A12 are protein complexes that are produced by activated neutrophils, monocytes, and keratinocytes in psoriasis. Lipid-rich necrotic core (LRNC) is a high-risk coronary plaque feature previously found to be associated with cardiovascular risk factors and psoriasis severity. LRNC can decrease with biologic therapy, but how this occurs remains unknown. We investigated the relationship between S100 proteins, LRNC, and biologic therapy in psoriasis. S100A8/A9 associated with LRNC in fully adjusted models (β = 0.27, P = 0.009, n=125 psoriasis patients with available coronary CT angiography scans, LRNC analyses, and serum S100A7, S100A8, S100A9, S100A12, and S100A8/A9 levels). At one year, in patients receiving biologic therapy (36 of 73 patients had 1-year CCTA scans available), a 79% reduction in S100A8/A9 levels (-172 (-291.7-26.4) vs -29.9 (-137.9- 50.5) P = 0.04) and a 0.6 mm² reduction in average LRNC area (0.04 (-0.48-0.77) vs -0.56 (-1.8- 0.13); P = 0.02) were noted. These results highlight the potential role of S100A8/A9 in the development of high-risk coronary plaque in psoriasis.

S100A9 and SOCS3 as diagnostic biomarkers of acute myocardial infarction and their association with immune infiltration

Acute myocardial infarction (AMI) is one of the leading causes of death globally, with a mortality rate of over 20%. However, the diagnostic biomarkers frequently used in current clinical practice have limitations in both sensitivity and specificity, likely resulting in delayed diagnosis. This study aimed to identify potential diagnostic biomarkers for AMI and explored the possible mechanisms involved. Datasets were retrieved from the Gene Expression Omnibus. First, we identified differentially expressed genes (DEGs) and preserved modules, from which we identified candidate genes by LASSO (least absolute shrinkage and selection operator) regression and the SVM-RFE (support vector machine-recursive feature elimination) algorithm. Subsequently, we used ROC (receiver operating characteristic) analysis to evaluate the diagnostic accuracy of the candidate genes. Thereafter, functional enrichment analysis and an analysis of immune infiltration were implemented. Finally, we assessed the association between biomarkers and biological processes, infiltrated cells, clinical traits, tissues and time points. We identified nine preserved modules containing 1,016 DEGs and managed to construct a diagnostic model with high accuracy (GSE48060: AUC = 0.923; GSE66360: AUC = 0.973) incorporating two genes named S100A9 and SOCS3. Functional analysis revealed the pivotal role of inflammation; immune infiltration analysis indicated that eight cell types (monocytes, epithelial cells, neutrophils, CD8+ T cells, Th2 cells, NK cells, NKT cells and platelets) were likely involved in AMI. Furthermore, we observed that S100A9 and SOCS3 were correlated with inflammation, variably infiltrated cells, clinical traits of patients, sampling tissues and sampling time points. In conclusion, we suggested S100A9 and SOCS3 as diagnostic biomarkers of AMI and discovered their association with inflammation, infiltrated immune cells and other factors.

Cardiac remodelling - Part 1: From cells and tissues to circulating biomarkers. A review from the Study Group on Biomarkers of the Heart Failure Association of the European Society of Cardiology

Cardiac remodelling refers to changes in left ventricular structure and function over time, with a progressive deterioration that may lead to heart failure (HF) development (adverse remodelling) or vice versa a recovery (reverse remodelling) in response to HF treatment. Adverse remodelling predicts a worse outcome, whilst reverse remodelling predicts a better prognosis. The geometry, systolic and diastolic function and electric activity of the left ventricle are affected, as well as the left atrium and on the long term even right heart chambers. At a cellular and molecular level, remodelling involves all components of cardiac tissue: cardiomyocytes, fibroblasts, endothelial cells and leucocytes. The molecular, cellular and histological signatures of remodelling may differ according to the cause and severity of cardiac damage, and clearly to the global trend toward worsening or recovery. These processes cannot be routinely evaluated through endomyocardial biopsies, but may be reflected by circulating levels of several biomarkers. Different classes of biomarkers (e.g. proteins, non-coding RNAs, metabolites and/or epigenetic modifications) and several biomarkers of each class might inform on some aspects on HF development, progression and long-term outcomes, but most have failed to enter clinical practice. This may be due to the biological complexity of remodelling, so that no single biomarker could provide great insight on remodelling when assessed alone. Another possible reason is a still incomplete understanding of the role of biomarkers in the pathophysiology of cardiac remodelling. Such role will be investigated in the first part of this review paper on biomarkers of cardiac remodelling.

Within-person reproducibility of proteoforms related to inflammation and renal dysfunction

Protein biomarkers and microheterogeneity have attracted increasing attention in epidemiological and clinical research. Knowledge of within-person reproducibility over time is paramount to determine whether a single measurement accurately reflects an individual's long-term exposure. Yet, research investigating within-person reproducibility for proteoforms is limited. We investigated the reproducibility of the inflammatory markers C-reactive protein (CRP), serum amyloid A (SAA), and calprotectin (S100A8/9), and the renal function marker cystatin C (CnC) using a novel immuno-MALDI-TOF MS assay. Reproducibility, expressed as intraclass correlation coefficient (ICC), was calculated for 16 proteoforms using plasma samples of the Western Norway B Vitamin Intervention Trial (WENBIT) cohort collected 1-3 y apart from 295 stable angina pectoris (SAP) patients and 16 weeks apart from 38 subjects of the Intervention with Omega Fatty Acids in High-risk Patients with Hypertriglyceridemic Waist (OMEGA) trial with abdominal obesity but no other documented co-morbidities. ICCs for inflammatory markers were lower in WENBIT (CRP: 0.51, SAAt: 0.38, S100At: 0.31) compared to OMEGA subjects (CRP: 0.71, SAAt: 0.73, S100At: 0.48), while comparable for CnCt (WENBIT: 0.69, OMEGA: 0.67). Excluding SAP patients with elevated inflammation (CRP > 10 µg/ml) increased the ICC of SAAt to 0.55. Reduction of the time interval from 3 to 1 y in WENBIT group increased ICCs for all proteoforms. With a few exceptions ICCs did not differ between proteoforms of the same biomarker. ICCs were highest in OMEGA subjects with fair-to-good reproducibility for all markers. Reproducibility of SAA and S100A8/9 proteoforms in the WENBIT cohort was related to inflammation. This work will inform future clinical and epidemiological research which relies on single time point biomarker assessment to investigate inflammation and renal function.

Involvement of Oxidative Stress in Protective Cardiac Functions of Calprotectin

Calprotectin (CLP) belonging to the S-100 protein family is a heterodimeric complex (S100A8/S100A9) formed by two binding proteins. Upon cell activation, CLP stored in neutrophils is released extracellularly in response to inflammatory stimuli and acts as damage-associated molecular patterns (DAMPs). S100A8 and S100A9 possess both anti-inflammatory and anti-bacterial properties. The complex is a ligand of the toll-like receptor 4 (TLR4) and receptor for advanced glycation end (RAGE). At sites of infection and inflammation, CLP is a target for oxidation due to its co-localization with neutrophil-derived oxidants. In the heart, oxidative stress (OS) responses and S100 proteins are closely related and intimately linked through pathophysiological processes. Our review summarizes the roles of S100A8, S100A9 and CLP in the inflammation in relationship with vascular OS, and we examine the importance of CLP for the mechanisms driving in the protection of myocardium. Recent evidence interpreting CLP as a critical modulator during the inflammatory response has identified this alarmin as an interesting drug target.

Plasma Calprotectin Is Predictive for Short-Term Functional Outcomes of Acute Ischemic Stroke

Background

Blood-based prognostic biomarkers of acute ischemic stroke (AIS) are limiting. Calprotectin is suggested to be involved in directing post-stroke inflammatory conditions. However, the pathological alteration of circulating calprotectin in AIS is yet to be thoroughly elucidated. Therefore, this study aimed to investigate the levels and clinical relevance of calprotectin in AIS.

Methods

This study recruited 271 patients with AIS within 24 h since symptom onset and 145 non-stroke healthy controls (HC) from February 1, 2018, to Dec 31, 2020. Patients were followed up for 2 weeks for observation of functional outcomes, as determined by the National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS). Plasma calprotectin concentrations were determined by ELISA.

Results

Plasma calprotectin concentrations were significantly higher in patients with AIS compared with controls [patients vs. control: median (IQR) 54.2 (39.01–99.04) vs. 50.04 (35.42–61.22), p < 0.001]. Besides, patients with poor prognosis, as defined by mRS ≥ 3, had significantly higher calprotectin levels than patients with good prognosis [poor prognosis patients vs. good prognosis patients: median (IQR) 61.99 (47.52–108) vs. 43.36 (33.39–60.2), p < 0.001]. Plasma calprotectin levels were positively associated with the disease severity of AIS, as reflected by infarction volume and NIHSS score at baseline. Furthermore, baseline calprotectin was found to be independently associated with poor prognosis [odds ratio (OR): 1.02, 95% CI: 1.01–1.03] and disease progression (OR: 1.03, 95% CI: 1.02–1.04) of AIS during a 2-week follow-up, with adjustment of possible confounding factors.

Conclusion

Plasma calprotectin is associated with short-term functional outcomes of AIS.

S100A9 blockade improves the functional recovery after spinal cord injury via mediating neutrophil infiltration

Spinal cord injury (SCI) refers to damage to the spinal cord resulting from trauma, disease or degeneration. Controlling the inflammatory process and restoring neural homeostasis is hypothesized to prevent injury aggravation. S100 calcium-binding protein A9 (S100A9) is a pro-inflammatory alarm protein, which is expressed in and released by activated neutrophils. However, whether S100A9 could serve as an effective target for the treatment of SCI has not been reported to date. In the present study, a T10 spinal cord contusion injury model was established in Sprague-Dawley rats. S100A9 expression level was determined in the serum and injured spinal cord tissue via ELISA, reverse transcription-quantitative PCR (RT-qPCR) and western blotting. The S100A9-specific blocker, ABR-238901 (ABR), was administered during the inflammatory phase of SCI, as a form of treatment. Subsequently, the morphological structure, neuronal viability and inflammatory levels of injured spinal cord were observed by histopathology, immunohistochemistry and RT-qPCR. In the obtained results, S100A9 was found to be highly expressed in the injured spinal cord and serum in the first 3 days after SCI. However, at 28 days after surgery, ABR treatment significantly improved motor function, reduced the cavity formation and neutrophil infiltration in the lesion, which was verified via H&E staining and immunohistochemistry for myeloperoxidase. Furthermore, ABR treatment was found to effectively improve the survival and viability of neurons, as shown via Nissl staining and immunofluorescence of the synaptic plasticity markers, microtubule associated protein 2 and neurofilament 200. Moreover, S100A9 blockade effectively upregulated the mRNA expression level of the anti-inflammatory genes, IL-4 and IL-10 and downregulated the mRNA expression level of the pro-inflammatory factors, IL-1β, IL-6 and TNF-α. In addition, S100A9 blockade notably alleviated the apoptosis level of the injured nerve cells. Therefore, the findings of the present study revealed that S100A9 may be a useful target for the treatment of SCI.

S100A8 and S100A9 are elevated in chronically threatened ischemic limb muscle and induce ischemic mitochondrial pathology in mice

Objective

The objective of the present study was to determine whether elevated levels of S100A8 and S100A9 (S100A8/A9) alarmins contribute to ischemic limb pathology.

Methods

Gastrocnemius muscle was collected from control patients without peripheral arterial disease (PAD; n = 14) and patients with chronic limb threatening limb ischemia (CLTI; n = 14). Mitochondrial function was assessed in permeabilized muscle fibers, and RNA and protein analyses were used to quantify the S100A8/A9 levels. Additionally, a mouse model of hindlimb ischemia with and without exogenous delivery of S100A8/A9 was used.

Results

Compared with the non-PAD control muscles, CLTI muscles displayed significant increases in the abundance of S100A8 and S100A9 at both mRNA and protein levels (P < .01). The CLTI muscles also displayed significant impairment in mitochondrial oxidative phosphorylation and increased mitochondrial hydrogen peroxide production compared with the non-PAD controls. The S100A8/A9 levels correlated significantly with the degree of muscle mitochondrial dysfunction (P < .05 for all). C57BL6J mice treated with recombinant S100A8/A9 displayed impaired perfusion recovery and muscle mitochondrial impairment compared with the placebo-treated mice after hindlimb ischemia surgery. These mitochondrial deficits observed after S100A8/A9 treatment were confirmed in the muscle cell culture system under normoxic conditions.

Conclusions

The S100A8/A9 levels were increased in CLTI limb muscle specimens compared with the non-PAD control muscle specimens, and the level of accumulation was associated with muscle mitochondrial impairment. Elevated S100A8/A9 levels in mice subjected to hindlimb ischemia impaired perfusion recovery and mitochondrial function. Together, these findings suggest that the inflammatory mediators S100A8/A9 might be directly involved in ischemic limb pathology.

Despite improvements in the surgical management of chronic limb threatening limb ischemia (CLTI), the rates of major adverse limb events have remained high. Skeletal muscle has emerged as a strong predictor of outcomes in peripheral arterial disease (PAD)/CLTI; however, a complete understanding of muscle pathology in CLTI is lacking. This study identified elevated S100A8 and S100A9 alarmin proteins as a characteristic of CLTI muscle specimens and that the S100A8/A9 levels are associated with the degree of mitochondrial impairment in patient limb muscle specimens. Using a mouse model of PAD, treatment with S100A8/A9 exacerbated ischemic limb pathology, including impaired limb perfusion recovery and muscle mitochondrial impairment. Taken together, these findings connect the inflammatory milieu in the CLTI limb to exacerbated limb muscle outcomes via mitochondrial alterations.

Neutrophil-Derived Protein S100A8/A9 Alters the Platelet Proteome in Acute Myocardial Infarction and Is Associated With Changes in Platelet Reactivity

Supplemental Digital Content is available in the text.

Objective:

Platelets are central to acute myocardial infarction (MI). How the platelet proteome is altered during MI is unknown. We sought to describe changes in the platelet proteome during MI and identify corresponding functional consequences.

Approach and Results:

Platelets from patients experiencing ST-segment–elevation MI (STEMI) before and 3 days after treatment (n=30) and matched patients with severe stable coronary artery disease before and 3 days after coronary artery bypass grafting (n=25) underwent quantitative proteomic analysis. Elevations in the proteins S100A8 and S100A9 were detected at the time of STEMI compared with stable coronary artery disease (S100A8: FC, 2.00; false discovery rate, 0.05; S100A9: FC, 2.28; false discovery rate, 0.005). During STEMI, only S100A8 mRNA and protein levels were correlated in platelets (R=0.46, P=0.012). To determine whether de novo protein synthesis occurs, activated platelets were incubated with 13C-labeled amino acids for 24 hours and analyzed by mass spectrometry. No incorporation was confidently detected. Platelet S100A8 and S100A9 was strongly correlated with neutrophil abundance at the time of STEMI. When isolated platelets and neutrophils were coincubated under quiescent and activated conditions, release of S100A8 from neutrophils resulted in uptake of S100A8 by platelets. Neutrophils released S100A8/A9 as free heterodimer, rather than in vesicles or extracellular traps. In the community-based Bruneck study (n=338), plasma S100A8/A9 was inversely associated with platelet reactivity—an effect abrogated by aspirin.

Conclusions:

Leukocyte-to-platelet protein transfer may occur in a thromboinflammatory environment such as STEMI. Plasma S100A8/A9 was negatively associated with platelet reactivity. These findings highlight neutrophils as potential modifiers for thrombotic therapies in coronary artery disease.

Positive correlations between plasma BPI level and MPO-DNA and S100A8/A9 in myocardial infarction

Bactericidal/permeability-increasing protein (BPI) exhibits a number of important characteristics. RNA-seq analysis revealed that the BPI expression was increased in platelets of (non)ST-elevated myocardial infarction (NSTEMI/STEMI) patients. Activated platelets can induce NETosis which may be accompanied by the release of myeloperoxidase-DNA (MPO-DNA) and S100A8/A9. This study investigated the plasma BPI levels in myocardial infarction patients and its correlation with MPO-DNA and S100A8/A9. This prospective study recruited 80 control individuals, as well as 63 NSTEMI and 59 STEMI patients who were admitted to the First Affiliated Hospital of Bengbu Medical College for coronary angiography (CAG) and/or percutaneous coronary intervention (PCI) between May 1^, 2020 and August 31, 2020. Demographic and clinical characteristics, clinical indicators, hs-CRP, IL-1β, MPO-DNA (a circulated marker of NETs), circulating levels of S100A8/A9 and BPI were measured from each individual. The severity of coronary lesions was evaluated by the Gensini score, based on the results of the CAG. Pearson's or spearman's correlation was used to examine the correlation between BPI and the above-mentioned parameters, as well as the severity of coronary artery disease. Linear regression analysis was applied to identify the independent predictive factors of BPI. Received operating characteristic (ROC) curve analysis was used to evaluate the diagnostic efficacy of plasma BPI for MI. The plasma BPI levels increased by 8.76 times in the STEMI group and 5.38 times in the NSTEMI group compared to the control group. The plasma level of hs-CRP and IL-1β in both STEMI and NSTEMI groups were also significantly higher than the control group. In addition, the plasma levels of MPO-DNA and S100A8/A9 in the STEMI and NSTEMI groups were significantly higher than the control group. Plasma levels of BPI were positively correlated with IL-1β, hs-CRP, MPO-DNA and S100A8/A9. The correlation between BPI and the severity of coronary artery disease was also significant. The optimal cutoff value of plasma BPI was 35.1705 ng/ml for MI patients from the ROC curve analysis. Plasma BPI levels are increased in myocardial infarction patients and positively correlated with MPO-DNA and S100A8/A9. Plasma BPI level may serve as a potential biomarker of myocardial infarction.

Inflammatory markers and risk of cardiovascular mortality in relation to diabetes status in the HUNT study

Inflammatory markers have been associated with increased risk of cardiovascular mortality in general populations. We assessed whether these associations differ by diabetes status. From a population-based cohort study (n = 62,237) we included all participants with diabetes (n = 1753) and a control group without diabetes (n = 1818). Cox regression models were used to estimate hazard ratios (HRs) with 95% confidence intervals (CI) for possible associations with cardiovascular mortality of 4 different inflammatory markers; C-reactive protein (CRP), calprotectin, neopterin and lactoferrin. During a median follow-up of 13.9 years, 728 (20.4%) died from cardiovascular disease (CVD). After adjustment for age, sex and diabetes, the associations of all inflammatory markers with risk of cardiovascular mortality were log-linear (all P ≤ 0.017 for trend) and did not differ according to diabetes status (all P ≥ 0.53 for interaction). After further adjustments for established risk factors, only CRP remained independently associated with cardiovascular mortality. HRs were 1.22 (1.12–1.32) per standard deviation higher log_e CRP concentration and 1.91 (1.50–2.43) when comparing individuals in the top versus bottom quartile. The associations of CRP, calprotectin, lactoferrin and neopterin with cardiovascular mortality did not differ by diabetes, suggesting that any potential prognostic value of these markers is independent of diabetes status.

Collagenous Gastritis in Children: Incidence, Disease Course, and Associations With Autoimmunity and Inflammatory Markers

Collagenous gastritis (CG), a rare disorder of unknown etiology, has been postulated to have immune-mediated mechanisms. We investigated (i) the incidence and prevalence of CG in a pediatric population; (ii) the clinical, endoscopic, and histologic characteristics of childhood-onset CG; and (iii) the evidence for autoimmunity and/or inflammatory activity in these patients.

Plasma calprotectin as a biomarker of mortality at antiretroviral treatment initiation in advanced HIV - pilot study

Background: In advanced HIV, significant mortality occurs soon after starting antiretroviral treatment (ART) in low- and middle-incomes countries. Calprotectin is a biomarker of innate response to infection and inflammatory conditions. We examined the association between plasma calprotectin collected before ART treatment and mortality among individuals with advanced HIV.   Methods: We conducted a pilot case-cohort study among HIV infected adults and adolescents over 13 years old with CD4+ <100/mm3 at ART initiation at two Kenyan sites. Participants received three factorial randomised interventions in addition to ART within the REALITY trial (ISRCTN43622374). Calprotectin collected at baseline (before ART) and after 4 weeks of treatment was measured in archived plasma of those who died within 24 weeks (cases) and randomly selected participants who survived (non-cases). Association with mortality was assessed using Cox proportional hazards models with inverse sampling probability weights and adjusted for age, sex, site, BMI, viral load, randomised treatments, and clustered by CD4+ count (0-24, 25-49, and 50-99 cells/mm3).   Results: Baseline median (IQR) plasma calprotectin was 6.82 (2.65-12.5) µg/ml in cases (n=39) and 5.01 (1.92-11.5) µg/ml in non-cases (n=58). Baseline calprotectin was associated with age, neutrophil count and the presence of cough, but not other measured indicators of infection. In adjusted multivariable models, baseline calprotectin was associated with subsequent mortality: HR 1.64 (95% CI 1.11 - 2.42) and HR 2.77 (95% CI 1.58 - 4.88) for deaths during the first twenty-four and four weeks respectively. Calprotectin levels fell between baseline and 4 weeks among both cases and non-cases irrespective of randomised interventions.   Conclusions: Among individuals with advanced HIV starting ART in Kenya, plasma calprotectin may have potential as a biomarker of early mortality. Validation in larger studies, comparison with other biomarkers and investigation of the sources of infection and inflammation are warranted.

S100A8/A9 in Myocardial Infarction: A Promising Biomarker and Therapeutic Target

Myocardial infarction (MI), the main cause of cardiovascular-related deaths worldwide, has long been a hot topic because of its threat to public health. S100A8/A9 has recently attracted an increasing amount of interest as a crucial alarmin that regulates the pathogenesis of cardiovascular disease after its release from myeloid cells. However, the role of S100A8/A9 in the etiology of MI is not well understood. Here, we elaborate on the critical roles and potential mechanisms of S100A8/A9 driving the pathogenesis of MI. First, cellular source of S100A8/A9 in infarcted heart is discussed. Then we highlight the effect of S100A8/A9 heterodimer in the early inflammatory period and the late reparative period of MI as well as myocardial ischemia/reperfusion (I/R) injury. Moreover, the predictive value of S100A8/A9 for the risk of recurrence of cardiovascular events is elucidated. Therefore, this review focuses on the molecular mechanisms of S100A8/A9 in MI pathogenesis to provide a promising biomarker and therapeutic target for MI.

Plasma S100A8/A9 Concentrations and Clinical Outcomes of Ischemic Stroke in 2 Independent Multicenter Cohorts

BACKGROUND

S100A8/A9 is implicated in inflammation mechanisms related to atherosclerosis and plaque vulnerability, but it remains unclear whether S100A8/A9 is associated with the prognosis of ischemic stroke. The aim of this study was to investigate these associations in 2 independent multicenter cohorts.

METHODS

Plasma S100A8/A9 concentrations at baseline were measured among 4785 patients with ischemic stroke from 2 independent cohorts: Infectious Factors, Inflammatory Markers, and Prognosis of Acute Ischemic Stroke (IIPAIS) and China Antihypertensive Trial in Acute Ischemic Stroke (CATIS). The primary outcome was a composite outcome of death or major disability at 3 months after ischemic stroke. Secondary outcomes were major disability, death, and a composite outcome of death or vascular events.

RESULTS

Among the combined participants of IIPAIS and CATIS, the adjusted odds ratios associated with the highest quartile of plasma S100A8/A9 were 2.11 (95% CI, 1.66-2.68) for the primary outcome and 1.62 (95% CI, 1.27-2.07) for the secondary outcome of major disability; adjusted hazard ratios were 4.14 (95% CI, 2.10-8.15) for the secondary outcome of death and 2.08 (95% CI, 1.38-3.13) for the composite outcome of death or vascular events. Each SD increase of log-transformed S100A8/A9 was associated with 28% (95% CI, 18%-39%; P < 0.001) increased risk of the primary outcome. Multivariable-adjusted spline regression analyses showed a linear association between plasma S100A8/A9 concentrations and primary outcome (P < 0.001 for linearity). Subgroup analyses further confirmed these associations.

CONCLUSIONS

High plasma S100A8/A9 concentrations at baseline were independently associated with increased risks of adverse clinical outcomes at 3 months after ischemic stroke, suggesting that S100A8/A9 might have a role as a prognostic marker of ischemic stroke.

Plasma calprotectin was associated with platelet activation and no-reflow phenomenon in acute coronary syndrome

Background

No-reflow occurs in 3–4% of all percutaneous coronary interventions (PCIs) and has a strong negative impact on clinical outcomes of acute coronary syndrome (ACS). Therefore, the discovery of a biomarker that can early predict the occurrence of no-reflow has great clinical significance. Multiple factors including platelet activation are relevant to no-reflow. Calprotectin is found to be a biomarker of plaque instability and is identified to be a novel diagnostic and prognostic biomarker of cardiovascular diseases. The association of plasma calprotectin with platelet activation and no-reflow phenomenon in ACS is not clear.

Methods

In this prospective study performed at Yantai Yuhuangding Hospital from 2017 to 2018, a total of 176 Chinese patients with ACS who had undergone PCIs were recruited consecutively, aged from 30 to 88 years. Angiographic no-reflow was defined as thrombolysis in myocardial infarction grade less than 3. Blood samples were collected immediately at admission for the detection of plasma calprotectin and platelet–monocyte aggregates formation. Statistical analysis was performed for the variable’s comparisons between groups and the prediction value of plasma calprotectin for no-reflow.

Results

The mean age of the 176 included ACS patients were 64(±11) years and acute ST-segment elevation myocardial infarction (STEMI) was present in 41.5% of patients. Twenty-two patients had no-reflow during the PCI procedures and the prevalence was 12.5%. Patients with higher plasma calprotectin had a higher level of platelet–monocyte aggregates (PMA) and a higher prevalence of no-reflow (p < 0.001). The multivariate regression showed that plasma calprotectin and admission hs-cTnI were independently associated with PMA, while plasma calprotectin and serum LDL-c were independent predictors of no-reflow (p < 0.001 and p = 0.017). AUC of calprotectin for predicting no-reflow were 0.898. The cut-off value of plasma calprotectin for no-reflow was 4748.77 ng/mL with a sensitivity of 0.95 and a specificity of 0.77.

Conclusion

Plasma calprotectin was associated with platelet activation and may act as an early predictive biomarker of no-reflow in patients with acute coronary syndrome.

Cigarette smoke induction of S100A9 contributes to chronic obstructive pulmonary disease

S100 calcium-binding protein A9 (S100A9) is elevated in plasma and bronchoalveolar lavage fluid (BALF) of patients with chronic obstructive pulmonary disease (COPD), and aging enhances S100A9 expression in several tissues. Currently, the direct impact of S100A9-mediated signaling on lung function and within the aging lung is unknown. Here, we observed that elevated S100A9 levels in human BALF correlated with age. Elevated lung levels of S100A9 were higher in older mice compared with in young animals and coincided with pulmonary function changes. Both acute and chronic exposure to cigarette smoke enhanced S100A9 levels in age-matched mice. To examine the direct role of S100A9 on the development of COPD, S100a9^-/- mice or mice administered paquinimod were exposed to chronic cigarette smoke. S100A9 depletion and inhibition attenuated the loss of lung function, pressure-volume loops, airway inflammation, lung compliance, and forced expiratory volume in 0.05 s/forced vital capacity, compared with age-matched wild-type or vehicle-administered animals. Loss of S100a9 signaling reduced cigarette smoke-induced airspace enlargement, alveolar remodeling, lung destruction, ERK and c-RAF phosphorylation, matrix metalloproteinase-3 (MMP-3), matrix metalloproteinase-9 (MMP-9), monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6), and keratinocyte-derived chemokine (KC) release into the airways. Paquinimod administered to nonsmoked, aged animals reduced age-associated loss of lung function. Since fibroblasts play a major role in the production and maintenance of extracellular matrix in emphysema, primary lung fibroblasts were treated with the ERK inhibitor LY3214996 or the c-RAF inhibitor GW5074, resulting in less S100A9-induced MMP-3, MMP-9, MCP-1, IL-6, and IL-8. Silencing Toll-like receptor 4 (TLR4), receptor for advanced glycation endproducts (RAGE), or extracellular matrix metalloproteinase inducer (EMMPRIN) prevented S100A9-induced phosphorylation of ERK and c-RAF. Our data suggest that S100A9 signaling contributes to the progression of smoke-induced and age-related COPD.

Dynamical modeling of pro- and anti-inflammatory cytokines in the early stage of septic shock

A dynamical model of the pathophysiological behaviors of IL18 and IL10 cytokines with their receptors is tested against data for the case of early sepsis. The proposed approach considers the surroundings (organs and bone marrow) and the different subsystems (cells and cyctokines). The interactions between blood cells, cytokines and the surroundings are described via mass balances. Cytokines are adsorbed onto associated receptors at the cell surface. The adsorption is described by the Langmuir model and gives rise to the production of more cytokines and associated receptors inside the cell. The quantities of pro and anti-inflammatory cytokines present in the body are combined to give global information via an inflammation level function which describes the patient’s state. Data for parameter estimation comes from the Sepsis 48 H database. Comparisons between patient data and simulations are presented and are in good agreement. For the IL18/IL10 cytokine pair, 5 key parameters have been found. They are linked to pro-inflammatory IL18 cytokine and show that the early sepsis is driven by components of inflammatory character.

Epigenetic Regulation of S100A9 and S100A12 Expression in Monocyte-Macrophage System in Hyperglycemic Conditions

The number of diabetic patients in Europe and world-wide is growing. Diabetes confers a 2-fold higher risk for vascular disease. Lack of insulin production (Type 1 diabetes, T1D) or lack of insulin responsiveness (Type 2 diabetes, T2D) causes systemic metabolic changes such as hyperglycemia (HG) which contribute to the pathology of diabetes. Monocytes and macrophages are key innate immune cells that control inflammatory reactions associated with diabetic vascular complications. Inflammatory programming of macrophages is regulated and maintained by epigenetic mechanisms, in particular histone modifications. The aim of our study was to identify the epigenetic mechanisms involved in the hyperglycemia-mediated macrophage activation. Using Affymetrix microarray profiling and RT-qPCR we identified that hyperglycemia increased the expression of S100A9 and S100A12 in primary human macrophages. Expression of S100A12 was sustained after glucose levels were normalized. Glucose augmented the response of macrophages to Toll-like receptor (TLR)-ligands Palmatic acid (PA) and Lipopolysaccharide (LPS) i.e., pro-inflammatory stimulation. The abundance of activating histone Histone 3 Lysine 4 methylation marks (H3K4me1, H3K4me3) and general acetylation on histone 3 (AceH3) with the promoters of these genes was analyzed by chromatin immunoprecipitation. Hyperglycemia increased acetylation of histones bound to the promoters of S100A9 and S100A12 in M1 macrophages. In contrast, hyperglycemia caused a reduction in total H3 which correlated with the increased expression of both S100 genes. The inhibition of histone methyltransferases SET domain-containing protein (SET)7/9 and SET and MYND domain-containing protein (SMYD)3 showed that these specifically regulated S100A12 expression. We conclude that hyperglycemia upregulates expression of S100A9, S100A12 via epigenetic regulation and induces an activating histone code on the respective gene promoters in M1 macrophages. Mechanistically, this regulation relies on action of histone methyltransferases SMYD3 and SET7/9. The results define an important role for epigenetic regulation in macrophage mediated inflammation in diabetic conditions.

Serum alarmin S100A8/S100A9 levels and its potential role as biomarker in myocarditis

Aims

The alarmin S100A8/S100A9 (S100A8/A9) is released by activated monocytes/macrophages and neutrophils in the setting lymphocytic myocarditis (MC). We recently demonstrated its therapeutic potential in experimental acute MC. Now, we investigated the diagnostic relevance of S100A8/A9 serum levels in patients with suspected acute and chronic MC and in patients with heart failure without cardiac inflammation.

Methods and Results

Serum S100A8/A9 levels were analysed in patients with a recent onset of MC [≤ 30 days, n = 32; ejection fraction (EF): 45.4 ± 12.9%], dilated cardiomyopathy patients with inflammation (n = 112; EF: 29.0 ± 11.4%), or without inflammation (n = 58; EF: 26.6 ± 9.3%), and controls (n = 25; EF: 68.5 ± 4.6%), by using specific ELISAs. Blood samples were collected at Time Point 1 (T1), where also endomyocardial biopsies (EMBs) were withdrawn. Patients with a recent onset of MC showed a 4.6‐fold increase in serum S100A8/A9 levels vs. controls (MC: 1948 ± 1670 ng/mL vs. controls: 426 ± 307 ng/mL; P < 0.0001). Serum S100A8/A9 correlated with the disease activity, represented by EMB‐derived counts of inflammatory cells (CD3: r = 0.486, P = 0.0047, lymphocyte function‐associated antigen‐1: r = 0.558, P = 0.0009, macrophage‐1 antigen: r = 0.434, P = 0.013), the EMB mRNA levels of S100A8, S100A9 (r = 0.541, P = 0.002), and left ventricular ejection fraction (LVEF: r = 0.498, P = 0.0043). EMB immunofluorescence co‐stainings display macrophages/monocytes and neutrophils as the main source of S100A8 and S100A9 in recent onset MC. The diagnostic value of serum alarmin levels (cut‐off 583 ng/mL) was characterized by a specificity of 92%, a sensitivity of 90.6%, positive predictive value of 93.5%, negative predictive value of 88.5%, and an accuracy of 0.949 (95% confidence interval [0.89–1]). In a subgroup of MC patients, S100A8/A9 serum levels and EMBs at T1 (n = 12) and a follow‐up visit (T2, n = 12, mean follow‐up 8.5 months) were available. A fall of serum S100A8/A9 (T1: 2208 ± 1843 ng/mL vs. T2: 888.8 ± 513.7 ng/mL; P = 0.00052) was associated with a reduced cardiac inflammation (CD3 T1: 70.02 ± 107.4 cells per square millimetre vs. T2: 59.18 ± 182.5 cells per square millimetre; P = 0.0342, lymphocyte function‐associated antigen‐1 T1: 133.5 ± 187.1 cells per square millimetre vs. T2: 74.12 ± 190.5 cells per square millimetre; P = 0.0186, and macrophage‐1 antigen T1: 132.6 ± 129.5 cells per square millimetre vs. T2: 54.41 ± 65.16 cells per square millimetre; P = 0.0015). Serum S100A8/A9 levels were only slightly increased in patients within the chronic phase of MC and in heart failure patients without inflammation vs. controls.

Conclusions

Serum S100A8/A9 might serve as an additional tool in the diagnostic workup of suspected acute MC patients.

A Toolbox of Potential Immune-Related Therapies for Inflammatory Cardiomyopathy

Myocarditis is a multifactorial disorder, characterized by an inflammatory reaction in the myocardium, predominantly triggered by infectious agents, but also by antigen mimicry or autoimmunity in susceptible individuals. Unless spontaneously resolved, a chronic inflammatory course concludes with cardiac muscle dysfunction portrayed by ventricular dilatation, clinically termed inflammatory cardiomyopathy (Infl-CM). Treatment strategies aim to resolve chronic inflammation and preserve cardiac function. Beside standard heart failure treatments, which only play a supportive role in this condition, systemic immunosuppressants are used to diminish inflammatory cell function at the cost of noxious side effects. To date, the treatment protocols are expert-based without large clinical evidence. This review describes concept and contemporary strategies to alleviate myocardial inflammation and sheds light on potential inflammatory targets in an evidence-based order.

S100A9 Links Inflammation and Repair in Myocardial Infarction

RATIONALE

The alarmin S100A9 has been identified as a potential therapeutic target in myocardial infarction. Short-term S100A9 blockade during the inflammatory phase post-myocardial infarction inhibits systemic and cardiac inflammation and improves cardiac function long term.

OBJECTIVE

To evaluate the impact of S100A9 blockade on postischemic cardiac repair.

METHODS AND RESULTS

We assessed cardiac function, hematopoietic response, and myeloid phagocyte dynamics in WT (wild type) C57BL/6 mice with permanent coronary artery ligation, treated with the specific S100A9 blocker ABR-238901 for 7 or 21 days. In contrast to the beneficial effects of short-term therapy, extended S100A9 blockade led to progressive deterioration of cardiac function and left ventricle dilation. The treatment reduced the proliferation of Lin^-Sca-1⁺c-Kit⁺ hematopoietic stem and progenitor cells in the bone marrow and the production of proreparatory CD150⁺CD48^-CCR2⁺ hematopoietic stem cells. Monocyte trafficking from the spleen to the myocardium and subsequent phenotype switching to reparatory Ly6C^loMerTK^hi macrophages was also impaired, leading to inefficient efferocytosis, accumulation of apoptotic cardiomyocytes, and a larger myocardial scar. The transcription factor Nur77 (Nr4a1 [nuclear receptor subfamily 4 group A member 1]) mediates the transition from inflammatory Ly6C^hi monocytes to reparatory Ly6C^lo macrophages. S100A9 upregulated the levels and activity of Nur77 in monocytes and macrophages in vitro and in Ly6C^hi/int monocytes in vivo, and S100A9 blockade antagonized these effects. Finally, the presence of reparatory macrophages in the myocardium was also impaired in S100A9^-/- mice with permanent myocardial ischemia, leading to depressed cardiac function long term.

CONCLUSIONS

We show that S100A9 plays an important role in both the inflammatory and the reparatory immune responses to myocardial infarction. Long-term S100A9 blockade negatively impacts cardiac recovery and counterbalances the beneficial effects of short-term therapy. These results define a therapeutic window targeting the inflammatory phase for optimal effects of S100A9 blockade as potential immunomodulatory treatment in acute myocardial infarction.

Plasma calprotectin as a biomarker of mortality at antiretroviral treatment initiation in advanced HIV - pilot study

Background: In advanced HIV, significant mortality occurs soon after starting antiretroviral treatment (ART) in low- and middle-incomes countries. Calprotectin is a biomarker of innate response to infection and inflammatory conditions. We examined the association between plasma calprotectin at initiation of ART and mortality among individuals with advanced HIV. Methods: We conducted a pilot case-cohort study among HIV infected adults and children over 5 years old with CD4 + <100/mm 3 at ART initiation at two Kenyan sites. Participants received three factorial randomised interventions in addition to ART within the REALITY trial ( ISRCTN43622374). Calprotectin was measured by ELISA in archived plasma of those who died within 24 weeks (cases) and randomly selected participants who survived for 48 weeks (non-cases) for whom samples were available. Factors associated with baseline plasma calprotectin were investigated using linear regression. To test association with mortality, Cox proportional hazards models with inverse sampling probability weights and adjusted for age, sex, site, BMI, viral load, randomised treatments, and clustered by CD4 count were fitted. Results: Baseline median (IQR) plasma calprotectin was 6.82 (2.65-12.5) µg/ml in cases (n=39) and 5.01 (1.92-11.5) µg/ml in non-cases (n=58). Baseline calprotectin was associated with age, neutrophil count and the presence of cough, but not other measured indicators of infection. In adjusted multivariable models, baseline calprotectin was associated with subsequent mortality: HR 1.64 (95% CI 1.11 - 2.42) and HR 2.77 (95% CI 1.58 - 4.88) for deaths during the first twenty-four and four weeks respectively. Calprotectin levels fell between baseline and 4 weeks among both cases and non-cases irrespective of randomised interventions. Conclusion: Among individuals with advanced HIV starting ART in Kenya, plasma calprotectin may have potential as a biomarker of early mortality. Validation in larger studies, comparison with other biomarkers and investigation of the sources of infection and inflammation are warranted.

Management of Myocarditis-Related Cardiomyopathy in Adults

Myocarditis is generally a mild and self-limited consequence of systemic infection of cardiotropic viruses. However, patients can develop a temporary or permanent impairment of cardiac function including acute cardiomyopathy with hemodynamic compromise or severe arrhythmias. In this setting, specific causes of inflammation are associated with variable risks of death and transplantation. Recent translational studies suggest that treatments tailored to specific causes of myocarditis may impact clinical outcomes when added to guideline-directed medical care. This review summarizes recent advances in translational research that influence the utility of endomyocardial biopsy for the management of inflammatory cardiomyopathies. Emerging therapies for myocarditis based on these mechanistic hypotheses are entering clinical trials and may add to the benefits of established heart failure treatment.

High Plasma sRAGE (Soluble Receptor for Advanced Glycation End Products) Is Associated With Slower Carotid Intima-Media Thickness Progression and Lower Risk for First-Time Coronary Events and Mortality

Objective- RAGE (receptor for advanced glycation end products) and EMMPRIN (extracellular matrix metalloproteinase inducer) are immune receptors for proinflammatory mediators. These receptors can also be found in a soluble form in the circulation. Soluble RAGE (sRAGE) has shown atheroprotective properties in animal studies, possibly by acting as a decoy receptor for its ligands. Whether sEMMPRIN (soluble EMMPRIN) has similar roles is unknown. We hypothesized that sRAGE and sEMMPRIN might be associated with vascular disease progression, incident coronary events, and mortality. Approach and Results- We measured baseline sRAGE and sEMMPRIN in 4612 cardiovascular disease-free individuals from the population-based Malmö Diet and Cancer cohort. Measurements of intima-media thickness in the common carotid artery were performed at inclusion and after a median of 16.5 years. sRAGE was negatively correlated with carotid intima-media thickness progression, independently of traditional cardiovascular risk factors, kidney function, and hsCRP (high sensitive C-reactive protein). Additionally, sRAGE was associated with decreased risk for major adverse coronary events (hazard ratio=0.90 [0.82-0.97]; P=0.009) and mortality (hazard ratio=0.93 [0.88-0.99]; P=0.011) during a follow-up period of 21 years. The relationship with mortality was independent of all considered potential confounders. We found no correlations between EMMPRIN, intima-media thickness progression, or prognosis. Conclusions- Individuals with high levels of circulating sRAGE have a slower rate of carotid artery disease progression and a better prognosis. Although its predictive value was too weak to promote sRAGE as a useful clinical biomarker in the population, the findings support further research into the potential anti-inflammatory and atheroprotective properties of this soluble receptor.

The Quest for Antiinflammatory and Immunomodulatory Strategies in Heart Failure

Intensive research over the last 3 decades has unequivocally demonstrated the relevance of inflammation in heart failure (HF). Despite our current and ever increasing knowledge about inflammation, the clinical success of antiinflammatory and immunomodulatory therapies in HF is still limited. This review outlines the complexity and diversity of inflammation, its reciprocal interaction with HF, and addresses future perspectives, calling for immunomodulatory therapies that are specific for factors that activate the immune system without the risk of nonspecific immune suppression.

S100a8/a9 Signaling Causes Mitochondrial Dysfunction and Cardiomyocyte Death in Response to Ischemic/Reperfusion Injury

Background:

Myocardial ischemia-reperfusion (MI/R) injury is a significant clinical problem without effective therapy. Unbiased omics approaches may reveal key MI/R mediators to initiate MI/R injury.

Methods:

We used a dynamic transcriptome analysis of mouse heart exposed to various MI/R periods to identify S100a8/a9 as an early mediator. Using loss/gain-of-function approaches to understand the role of S100a8/a9 in MI/R injury, we explored the mechanisms through transcriptome and functional experiment. Dynamic serum S100a8/a9 levels were measured in patients with acute myocardial infarction before and after percutaneous coronary intervention. Patients were prospectively followed for the occurrence of major adverse cardiovascular events.

Results:

S100a8/a9 was identified as the most significantly upregulated gene during the early reperfusion stage. Knockout of S100a9 markedly decreased cardiomyocyte death and improved heart function, whereas hematopoietic overexpression of S100a9 exacerbated MI/R injury. Transcriptome/functional studies revealed that S100a8/a9 caused mitochondrial respiratory dysfunction in cardiomyocytes. Mechanistically, S100a8/a9 downregulated NDUF gene expression with subsequent mitochondrial complex I inhibition via Toll-like receptor 4/Erk–mediated Pparg coactivator 1 alpha/nuclear respiratory factor 1 signaling suppression. Administration of S100a9 neutralizing antibody significantly reduced MI/R injury and improved cardiac function. Finally, we demonstrated that serum S100a8/a9 levels were significantly increased 1 day after percutaneous coronary intervention in patients with acute myocardial infarction, and elevated S100a8/a9 levels were associated with the incidence of major adverse cardiovascular events.

Conclusions:

Our study identified S100a8/a9 as a master regulator causing cardiomyocyte death in the early stage of MI/R injury via the suppression of mitochondrial function. Targeting S100a8/a9-intiated signaling may represent a novel therapeutic intervention against MI/R injury.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT03752515

Neutrophil proteome shifts over the myocardial infarction time continuum

In response to myocardial infarction (MI), neutrophils (PMNs) are early responders that initiate the inflammatory reaction. Because macrophages and fibroblasts show polarization states after MI, we hypothesized PMNs also undergo phenotypic changes over the MI time course. The objective of the current study was to map the continuum of polarization phenotypes in cardiac neutrophils over the first week of MI. C57BL/6J male mice (3–6 months old) underwent permanent coronary artery ligation to induce MI, and PMNs were isolated from the infarct region at days 1, 3, 5, and 7 after MI. Day 0 served as a no MI negative control. Aptamer proteomics was performed on biological replicates (n = 10–12) for each time point. Day (D)1 MI neutrophils had a high degranulation profile with increased matrix metalloproteinase (MMP) activity. D3 MI neutrophil profiles showed upregulation of apoptosis and induction of extracellular matrix (ECM) organization. D5 MI neutrophils further increased their ECM reorganization profile. D7 MI neutrophils had a reparative signature that included expression of fibronectin, galectin-3, and fibrinogen to contribute to scar formation by stimulating ECM reorganization. Of note, fibronectin was a key modulator of degranulation, as it amplified MMP-9 release in the presence of an inflammatory stimulus. Our results indicate that neutrophils selectively degranulate over the MI time course, reflective of both their intrinsic protein profiles as well as the ECM environment in which they reside. MMPs, cathepsins, and ECM proteins were prominent neutrophil degranulation indicators.

Expression of S100 calcium-binding protein A8 in peripheral blood of patients with preeclampsia during pregnancy

A total of 30 late onset severe preeclampsia (LS-PE) patients and 30 early onset severe preeclampsia (ES-PE) patients were selected as Experimental group, and 30 normal pregnant were selected as Control group. Expression of S100 calcium-binding protein A8 (S100A8) mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR). Enzyme-linked immunosorbent assay (ELISA) was used to detect expression of S100A8 protein and inflammatory factors. Levels of uric acid (UA) and creatinine (CRE) were measured using an automatic biochemical analyzer. Urinary protein (UPRO) content was measured using biuret colorimetry. S100A8 levels were significantly higher in experimental groups than in control groups at mRNA and protein levels ( P < 0.05). Significantly increased contents of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-12, UA, CRE, and UPRO, and decreased level of IL-10 were found in experimental groups than in control groups ( P < 0.05). Compared with patients with ES-PE, significantly higher levels of TNF-α, IL-12, IL-6, UA, CRE, and UPRO, and lower level of IL-10 were found in patients with LS-PE. S100A8 plays pivotal roles in the development of preeclampsia through the interactions with other inflammatory factors.

Monocytes, Macrophages, and Metabolic Disease in Atherosclerosis

Atherosclerotic cardiovascular disease (CVD) is a lipid-driven chronic inflammatory disease, in which macrophages are responsible for taking up these lipids and driving disease progression. Over the years, we and others have uncovered key pathways that regulate macrophage number/function and identified how metabolic disorders such as diabetes and obesity, which are common risk factors for CVD, exacerbate these pathways. This ultimately accelerates the progression of atherosclerosis and hinders atherosclerotic regression. In this review, we discuss the different types of macrophages, from monocyte-derived macrophages, local macrophage proliferation, to macrophage-like vascular smooth muscle cells, that contribute to atherosclerosis as well as myeloid-derived suppressor cells that may have anti-atherogenic effects. We will also discuss how diabetes and obesity influence plaque macrophage accumulation and monocyte production (myelopoiesis) to promote atherogenesis as well as an exciting therapeutic target, S100A8/A9, which mediates myelopoiesis in response to both diabetes and obesity, shown to be effective in reducing atherosclerosis in pre-clinical models of diabetes.

Neutrophil-to-lymphocyte ratio and its relation with pro-inflammatory mediators, visceral adiposity and carotid intima-media thickness in population with obesity

BACKGROUND

Atherosclerosis represents a cardiovascular risk. Chronic inflammation is a key factor for atherogenic progression. Neutrophil-to-lymphocyte ratio (NLR) has been proposed as a novel biomarker for cardiovascular risks. We aimed to explore whether NLR was related to surrogate pro-atherogenic promoters driving atherogenic progression, as measured by carotid intima-media thickness (CIMT).

STUDY DESIGN

Thirty-one patients with obesity candidates for bariatric surgery were recruited from Centro Médico Nacional "20 de Noviembre", ISSSTE, Mexico City. The results are part of the "CROP" study (NCT03561987). NLR was calculated from routine complete blood count, and its relation with plasma pro-inflammatory mediators (hsCRP, TNF-α and IL-1β), adipokines (adiponectin and leptin), adiposity markers (visceral adipose tissue [VAT] determined from CT scan image and VAT individual adipocyte area at histological sample) and CIMT were determined.

RESULTS

Neutrophil-to-lymphocyte ratio correlated with hsCRP (Spearman's r = 0.70 [95% CI 0.46 to 0.85], P < 0.01), TNF-α (r = 0.69 [0.44 to 0.84], P < 0.0001) and adiponectin (r = -0.69 [-0.84 to -0.45], P < 0.03), as well as with VAT individual adipocyte area (r = 0.64 [0.37 to 0.81], P < 0.0001) and with VAT area (r = 0.43; [0.07 to 0.68], P < 0.01). Leptin and adiponectin showed further independent association with higher NLR (multivariate regression analysis OR 7.9 [95% CI 1.1 to 56.2] P = 0.03 and 0.1 [0.01 to 1.0] P = 0.05, respectively). Moreover, NLR distribution significantly varied between subgroups divided according to progressive CIMT (P = 0.05); whereas adiponectin and VAT adipocyte area associated with CIMT > 0.9 mm (univariate analysis OR 0.1 [0.01 to 1.0] P = 0.05 and 13.1 [1.4 to 126.3] P = 0.03, respectively).

CONCLUSION

Neutrophil-to-lymphocyte ratio was related to pro-inflammatory, adiposity biomarkers and progressive subclinical atherogenesis.

Exercise and Cardiovascular Progenitor Cells

Autologous stem/progenitor cell-based methods to restore blood flow and function to ischemic tissues are clinically appealing for the substantial proportion of the population with cardiovascular diseases. Early preclinical and case studies established the therapeutic potential of autologous cell therapies for neovascularization in ischemic tissues. However, trials over the past ∼15 years reveal the benefits of such therapies to be much smaller than originally estimated and a definitive clinical benefit is yet to be established. Recently, there has been an emphasis on improving the number and function of cells [herein generally referred to as circulating angiogenic cells (CACs)] used for autologous cell therapies. CACs include of several subsets of circulating cells, including endothelial progenitor cells, with proangiogenic potential that is largely exerted through paracrine functions. As exercise is known to improve CV outcomes such as angiogenesis and endothelial function, much attention is being given to exercise to improve the number and function of CACs. Accordingly, there is a growing body of evidence that acute, short-term, and chronic exercise have beneficial effects on the number and function of different subsets of CACs. In particular, recent studies show that aerobic exercise training can increase the number of CACs in circulation and enhance the function of isolated CACs as assessed in ex vivo assays. This review summarizes the roles of different subsets of CACs and the effects of acute and chronic exercise on CAC number and function, with a focus on the number and paracrine function of circulating CD34+ cells, CD31+ cells, and CD62E+ cells. © 2019 American Physiological Society. Compr Physiol 9:767-797, 2019.

Observational study on Swedish plaque psoriasis patients receiving narrowband-UVB treatment show decreased S100A8/A9 protein and gene expression levels in lesional psoriasis skin but no effect on S100A8/A9 protein levels in serum

S100A8 and S100A9 proteins are highly upregulated in patients with psoriasis and have been proposed as potential biomarkers for psoriasis. The present study was designed to analyze the effect of narrowband ultraviolet B therapy on these proteins.

S100A8, S100A9 gene expression and S100A8/A9 heterocomplex protein levels were analyzed in lesional and non-lesional skin before and after narrowband-UVB treatment in patients with chronic plaque type psoriasis. In addition, disease severity was measured by psoriasis area and severity index (PASI) and serum protein levels of S100A8/A9 were repeatedly analyzed. Narrowband-UVB treatment significantly reduced S100A8, S100A9 gene expression and S100A8/A9 protein levels in lesional skin while serum levels showed no significant change. No correlation between PASI and serum S100A8/A9 protein levels was found. These results implicate a role of S100A8/A9 in the anti-inflammatory effect of narrowband-UVB. Serum S100A8/A9 levels do not respond to treatment suggesting that serum S100A8/A9 does not originate from psoriasis skin keratinocytes. Serum S100A8/A9 levels do not correlate with PASI questioning serum S100A8/A9 as a biomarker for psoriasis skin activity.

Trial Registration: DRKS 00014817.

Cardiovascular endothelial inflammation by chronic coexposure to lead (Pb) and polycyclic aromatic hydrocarbons from preschool children in an e-waste recycling area

Lead (Pb) and polycyclic aromatic hydrocarbon (PAH) exposure is positively associated with cardiovascular disease (CVD), and the possible potential mechanism may be caused by damage to the endothelium by modulation of inflammatory processes. No comprehensive research shows co-exposure of Pb and PAH on cardiovascular endothelial inflammation in electronic waste (e-waste) exposed populations. Given this, the aim of this study is to provide evidence for a relationship between Pb and PAH co-exposure and cardiovascular endothelial inflammation, in an e-waste-exposed population, to delineate the link between a potential mechanism for CVD and environmental exposure. We recruited 203 preschool children (3-7 years) were enrolled from Guiyu (e-waste-exposed group, n = 105) and Haojiang (reference group, n = 98). Blood Pb levels and urinary PAH metabolites were measured. Percentages of T cells, CD4⁺ T cells and CD8⁺ T cells, complete blood counts, endothelial inflammation biomarker (serum S100A8/A9), and other inflammatory biomarkers [serum interleukin (IL)-6, IL-12p70, gamma interferon-inducible protein 10 (IP-10)] levels were evaluated. Blood Pb, total urinary hydroxylated PAH (ΣOHPAH), total hydroxynaphthalene (ΣOHNap) and total hydroxyfluorene (ΣOHFlu) levels, S100A8/A9, IL-6, IL-12p70 and IP-10 concentrations, absolute counts of monocytes, neutrophils, and leukocytes, as well as CD4⁺ T cell percentages were significantly higher in exposed children. Elevated blood Pb, urinary 2-hydroxynaphthalene (2-OHNap) and ΣOHFlu levels were associated with higher levels of IL-6, IL-12p70, IP-10, CD4⁺ T cell percentages, neutrophil and monocyte counts. Mediator models indicated that neutrophils exert the significant mediation effect on the relationship between blood Pb levels and S100A8/A9. IL-6 exerts a significant mediation effect on the relationship between blood Pb levels and IP-10, as well as the relationship between urinary ΣOHFlu levels and IP-10. Our results indicate that children with elevated exposure levels of Pb and PAHs have exacerbated vascular endothelial inflammation, which may indicate future CVD risk in e-waste recycling areas.

Identification of Candidate Genes and MicroRNAs for Acute Myocardial Infarction by Weighted Gene Coexpression Network Analysis

Background

Identification of potential molecular targets of acute myocardial infarction is crucial to our comprehensive understanding of the disease mechanism. However, studies of gene coexpression analysis via jointing multiple microarray data of acute myocardial infarction still remain restricted.

Methods

Microarray data of acute myocardial infarction (GSE48060, GSE66360, GSE97320, and GSE19339) were downloaded from Gene Expression Omnibus database. Three data sets without heterogeneity (GSE48060, GSE66360, and GSE97320) were subjected to differential expression analysis using MetaDE package. Differentially expressed genes having upper 25% variation across samples were imported in weighted gene coexpression network analysis. Functional and pathway enrichment analyses were conducted for genes in the most significant module using DAVID. The predicted microRNAs to regulate target genes in the most significant module were identified using TargetScan. Moreover, subpathway analyses using iSubpathwayMiner package and GenCLiP 2.0 were performed on hub genes with high connective weight in the most significant module.

Results

A total of 1027 differentially expressed genes and 33 specific modules were screened out between acute myocardial infarction patients and control samples. Ficolin (collagen/fibrinogen domain containing) 1 (FCN1), CD14 molecule (CD14), S100 calcium binding protein A9 (S100A9), and mitochondrial aldehyde dehydrogenase 2 (ALDH2) were identified as critical target molecules; hsa-let-7d, hsa-let-7b, hsa-miR-124-3, and hsa-miR-9-1 were identified as potential regulators of the expression of the key genes in the two biggest modules.

Conclusions

FCN1, CD14, S100A9, ALDH2, hsa-let-7d, hsa-let-7b, hsa-miR-124-3, and hsa-miR-9-1 were identified as potential candidate regulators in acute myocardial infarction. These findings might provide new comprehension into the underlying molecular mechanism of disease.

Association of circulating calprotectin with lipid profile in axial spondyloarthritis

Calprotectin (CPT) is released during inflammation, also in the context of atherosclerosis. The link between CPT and the atherosclerotic process was evaluated in several diseases. However, studies in axial spondyloarthritis (axSpA), associated with a high incidence of subclinical atherosclerosis, are scarce. Therefore, we assessed the association of CPT with subclinical atherosclerosis and metabolic risk factors in axSpA. CPT serum levels were measured by enzyme-linked immunosorbent assay in 163 axSpA patients and 63 controls. Subclinical atherosclerosis was determined in patients by carotid ultrasonography (assessing the presence/absence of carotid plaques and carotid intima-media thickness [cIMT]). Data on inflammation, disease activity, lipid profile and treatment were collected to evaluate its relationship with CPT. axSpA patients evidenced lower CPT levels than controls. CPT showed no association with plaques or cIMT in axSpA. CPT and HDL-cholesterol negatively correlated, while a positive association of CPT with the atherogenic index was disclosed. Additionally, axSpA patients with C-reactive protein values at diagnosis higher than 3 mg/L displayed higher CPT levels. Our study shows no relationship between CPT and markers of subclinical atherosclerosis in axSpA. Nevertheless, it demonstrates an association of CPT with adverse lipid profiles and inflammatory biomarkers, which could further influence on the development of atherosclerosis.

Genetic Variants Contributing to Circulating Matrix Metalloproteinase 8 Levels and Their Association With Cardiovascular Diseases: A Genome-Wide Analysis

BACKGROUND

Matrix metalloproteinase 8 (MMP-8) is a proinflammatory enzyme expressed mainly by neutrophils. Elevated serum and plasma concentrations of MMP-8 are associated with the risk for and outcome of cardiovascular diseases (CVDs). The origin of circulating MMP-8 is not completely clear.

METHODS AND RESULTS

We performed a genome-wide association study of serum MMP-8 levels in 2 populations comprising altogether 6049 individuals. Moreover, we studied whether MMP-8-associated variants are linked to increased risk of CVDs and overall mortality in >20 000 subjects. The strongest association with serum MMP-8 was found in locus 1q31.3, containing the gene for complement factor H (lead single nucleotide polymorphism: rs800292; P=2.4×10^-35). In functional experiments, activation of the alternative pathway of complement in the carriers of rs800292 minor allele (Ile62 in factor H) led to decreased release of MMP-8 from neutrophils compared with the major allele (Val62 in factor H). Another association was detected in 1q21.3, containing genes S100A8, S100A9, and S100A12 (strongest association: rs1560833; P=5.3×10^-15). The minor allele of rs1560833 was inversely associated with CVD (odds ratio [95% confidence interval]: 0.90 [0.82-0.99]; P=0.032) and the time to incident CVD event (hazard ratio [95% confidence interval]: 0.91 [0.84-0.99]; P=0.032) in men but not in women.

CONCLUSIONS

According to our results, the activation of the alternative pathway of the complement system strongly contributes to serum MMP-8 concentration. Genetic polymorphism in S100A9-S100A12-S100A8 locus affects serum and plasma MMP-8 and shows a suggestive association with the risk of CVDs. Our results show that genetic variation determines a significant portion of circulating MMP-8 concentrations.

Plasma calprotectin and risk of cardiovascular disease: Findings from the PREVEND prospective cohort study

BACKGROUND AND AIMS

We aimed to assess the association of circulating calprotectin, an inflammation-associated protein, with cardiovascular disease (CVD) risk and determine whether it improves risk prediction.

METHODS

Plasma calprotectin measurements were made at baseline in 5290 participants in the PREVEND prospective study. Hazard ratios (95% confidence intervals [CI]) for CVD were calculated.

RESULTS

After a median follow-up of 8.3 years, 339 first CVD events were recorded. Calprotectin concentration was correlated with several conventional risk factors as well as with high-sensitivity C-reactive protein (hsCRP) (r = 0.42). Calprotectin was log-linearly associated with CVD risk. The risk for CVD adjusted for conventional cardiovascular risk factors was 1.26 (95% CI, 1.13-1.41) per 1 standard deviation higher baseline log_e calprotectin, and was 1.24 (95% CI, 1.11-1.39) following further adjustment for triglycerides, body mass index, and other potential confounders. The association remained present after further adjustment for hsCRP 1.15 (95% CI, 1.02-1.30). Comparing extreme quartiles of plasma calprotectin levels, the corresponding adjusted HRs for CVD were 1.96 (1.37-2.82), 1.89 (1.31-2.72), and 1.56 (1.07-2.29). The association of calprotectin with CVD risk did not vary importantly in several relevant clinical subgroups. Adding calprotectin to the Framingham CVD Risk Score was associated with a C-index change (0.0016; p=0.42) difference in -2 log likelihood (p=0.038), IDI (0.0080; p < 0.001), and NRI (4.03%; p=0.024).

CONCLUSIONS

There is a log-linear association of calprotectin concentration with risk of CVD, which may be partly dependent on hsCRP. Adding calprotectin to conventional risk factors improves CVD risk assessment using measures of reclassification and -2 log likelihood.

Predictive value of serum calprotectin (S100A8/A9) for clinical response after starting or tapering anti-TNF treatment in patients with rheumatoid arthritis

Objectives

Calprotectin (S100A8/A9) has been correlated with disease activity in rheumatoid arthritis (RA). The aim of this study was to investigate the predictive value of serum calprotectin for clinical response after starting and tapering anti-tumour necrosis factor treatment in RA.

Methods

Serum samples and clinical outcomes were derived from two longitudinal RA studies.

At baseline (starting or tapering of adalimumab or etanercept), calprotectin levels were determined by ELISA. In the Biologic Individual Optimised Treatment Outcome Prediction (BIO-TOP) study, treatment effect was assessed after 6 months using the European League Against Rheumatism (EULAR) response criteria. In the Dose Reduction Strategies of Subcutaneous TNF Inhibitors (DRESS) study, patients were classified at 18 months as being successfully dose reduced, discontinued or not able to reduce the dose. Area under the receiver operating characteristic curves (AUC) were generated to evaluate the predictive value of calprotectin and logistic prediction models were created to assess its added value.

Results

In the BIO-TOP study, calprotectin levels were higher in responders (n=50: 985 ng/mL (p25–p75: 558–1417)) compared with non-responders (n=75: 645 ng/mL (p25–p75: 415–973), p=0.04).

AUC for predicting EULAR good response was 0.61 (95% CI 0.50 to 0.71). The prediction model with calprotectin (AUC 0.77, 95% CI 0.68 to 0.85) performed similarly to the baseline model (AUC 0.74, 95% CI 0.65 to 0.82, p=0.29). In the DRESS study, calprotectin levels were similar between the three groups (n=47; n=19; n=36) and calprotectin was not predictive for clinical response after tapering.

Conclusions

Serum calprotectin has some predictive value for clinical response after starting anti-TNF treatment, although it has no added value to other clinical factors. In patients with low disease activity, serum calprotectin is not predictive for clinical response after tapering anti-TNF treatment.

Trial registration number

NTR4647 (BIO-TOP study) and NTR3216 (DRESS study); Pre-results.

Secretion of the Phosphorylated Form of S100A9 from Neutrophils Is Essential for the Proinflammatory Functions of Extracellular S100A8/A9

S100A8 and S100A9 are members of the S100 family of cytoplasmic EF-hand Ca²⁺-binding proteins and are abundantly expressed in the cytosol of neutrophils. In addition to their intracellular roles, S100A8/A9 can be secreted in the extracellular environment and are considered as alarmins able to amplify the inflammatory response. The intracellular activity of S100A8/A9 was shown to be regulated by S100A9 phosphorylation, but the importance of this phosphorylation on the extracellular activity of S100A8/A9 has not yet been extensively studied. Our work focuses on the impact of the phosphorylation state of secreted S100A9 on the proinflammatory function of neutrophils. In a first step, we characterized the secretion of S100A8/A9 in different stimulatory conditions and investigated the phosphorylation state of secreted S100A9. Our results on neutrophil-like differentiated HL-60 (dHL-60) cells and purified human neutrophils showed a time-dependent secretion of S100A8/A9 when induced by phorbol 12-myristoyl 13-acetate and this secreted S100A9 was found in a phosphorylated form. Second, we evaluated the impact of this phosphorylation on proinflammatory cytokine expression and secretion in dHL-60 cells. Time course experiments with purified unphosphorylated or phosphorylated S100A8/A9 were performed and the expression and secretion levels of interleukin (IL)-1α, IL-1β, IL-6, tumor necrosis factor alpha, CCL2, CCL3, CCL4, and CXCL8 were measured by real-time PCR and cytometry bead array, respectively. Our results demonstrate that only the phosphorylated form of the complex induces proinflammatory cytokine expression and secretion. For the first time, we provide evidence that S100A8/PhosphoS100A9 is inducing cytokine secretion through toll-like receptor 4 signaling.

Stress-induced release of the S100A8/A9 alarmin is elevated in coronary artery disease patients with impaired cortisol response

Psychological stress is thought to be an important trigger of cardiovascular events, yet the involved pathways and mediators are largely unknown. Elevated systemic levels of the pro-inflammatory alarmin S100A8/A9 correlate with poor prognosis in coronary artery disease (CAD) patients. Here, we investigated the links between S100A8/A9 release and parameters of anti-inflammatory glucocorticoid secretion in two different cohorts subjected to a psychological stress test. In the first cohort of 60 CAD patients, psychological stress induced a rapid increase of circulating S100A8/A9. This rapid S100A8/A9 response strongly correlated with elevated evening saliva cortisol levels, suggesting an association with a dysregulated hypothalamic–pituitary–adrenal (HPA) axis. In the second cohort of 27 CAD patients and 28 controls, elevated S100A8/A9 levels were still detectable 24 h after stress in 40% of patients and 36% of controls, with a tendency for higher levels in patients. The sustained S100A8/A9 response was associated with a poor rapid cortisol release after stress in patients, but not in the control group. Our findings reveal for the first time that acute psychological stress induces elevated levels of S100A8/A9. We also provide hypothesis-generating evidence that dysregulated cortisol secretion in CAD patients might be associated with an exaggerated pro-inflammatory S100A8/A9 response.