Human neutrophil peptides: a novel potential mediator of inflammatory cardiovascular diseases

Role of neutrophils in different stages of atherosclerosis

Neutrophils constitute the first line of defense in human immunity and can be attracted to inflamed and infected sites by various chemokines. As essential players in immune processes, neutrophils theoretically play integral roles in the course of chronic inflammation-induced atherosclerosis. However, because neutrophils are rarely found in atherosclerotic lesions, their involvement in the pathophysiological progression of atherosclerosis has been largely underestimated or ignored. Recent research has revealed convincing evidence showing the presence of neutrophils in atherosclerotic lesions and has revealed neutrophil contributions to different atherosclerosis stages in mice and humans. This review describes the underlying mechanisms of neutrophils in different stages of atherosclerosis and highlights potential neutrophil-targeted therapeutic strategies relevant to atherosclerosis. An in-depth understanding of neutrophils' roles in atherosclerosis pathology will promote exploration of new methods for the prevention and treatment of atherogenesis and atherothrombosis.

Neutrophil (dys)function due to altered immuno-metabolic axis in type 2 diabetes: implications in combating infections

Metabolic and inflammatory pathways are highly interdependent, and both systems are dysregulated in Type 2 diabetes (T2D). T2D is associated with pre-activated inflammatory signaling networks, aberrant cytokine production and increased acute phase reactants which leads to a pro-inflammatory 'feed forward loop'. Nutrient 'excess' conditions in T2D with hyperglycemia, elevated lipids and branched-chain amino acids significantly alter the functions of immune cells including neutrophils. Neutrophils are metabolically active cells and utilizes energy from glycolysis, stored glycogen and β-oxidation while depending on the pentose phosphate pathway for NADPH for performing effector functions such as chemotaxis, phagocytosis and forming extracellular traps. Metabolic changes in T2D result in constitutive activation and impeded acquisition of effector or regulatory activities of neutrophils and render T2D subjects for recurrent infections. Increased flux through the polyol and hexosamine pathways, elevated production of advanced glycation end products (AGEs), and activation of protein kinase C isoforms lead to (a) an enhancement in superoxide generation; (b) the stimulation of inflammatory pathways and subsequently to (c) abnormal host responses. Neutrophil dysfunction diminishes the effectiveness of wound healing, successful tissue regeneration and immune surveillance against offending pathogens. Hence, Metabolic reprogramming in neutrophils determines frequency, severity and duration of infections in T2D. The present review discusses the influence of the altered immuno-metabolic axis on neutrophil dysfunction along with challenges and therapeutic opportunities for clinical management of T2D-associated infections.

Reversal of Azole Resistance in Candida albicans by Human Neutrophil Peptide

With the spread of AIDS and the increase in immunocompromised patients, multi-drug-resistant fungal infections have become a serious concern among clinicians, predominantly in the developing world. Therefore, developing novel strategies and new drugs is essential to overcome drug resistance in fungal pathogens. Antimicrobial peptides of human origin have been investigated as a potential treatment against Candida infections. In this study, human neutrophil peptide (HNP) was tested for its antifungal activity alone and in combination with fluconazole (FLC) against azole-susceptible and resistant C. albicans isolates, following CLSI guidelines. Susceptibility and combination interactions were also confirmed by MUSE cell viability assay and isobolograms for synergistic combinations, respectively. The effect of HNP on biofilm inhibition was determined spectrophotometrically and microscopically. Drug susceptibility testing showed minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) ranging from 7.813 to 62.5 µg/mL and 15.625 to 250 µg/mL against all the tested C. albicans strains. The combination activity of FLC with HNP exhibited synergistic and additive interactions in 43% of each and indifferent interaction in 14%, and none of the combinations showed antagonistic interaction. Furthermore, HNB inhibited biofilm formation in all the tested C. albicans isolates. At the respective MICs, HNP exhibited inhibitory effects on the activity of the drug efflux pumps and their genes. These results warrant the application of HNP as a mono- or combination therapy with FLC to treat azole-resistant C. albicans.

Plasma human neutrophil peptides as biomarkers of disease severity and mortality in patients with decompensated cirrhosis

BACKGROUND & AIMS

Human neutrophil peptides (HNP)-1, -2 and -3 are the most abundant proteins in neutrophil azurophilic granules and are rapidly released via neutrophil degranulation upon activation. The aims of our study were to assess the role of HNP1-3 as biomarkers of disease severity in patients with decompensated cirrhosis and their value in predicting short-term mortality.

METHODS

In this study, 451 patients with acutely decompensated cirrhosis (AD) were enrolled at the two medical centres. Overall, 281 patients were enrolled as the training cohort from October 2015 to April 2019, and 170 patients were enrolled as the validation cohort from June 2020 to February 2021. Plasma HNP1-3 levels were measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Plasma HNP1-3 increased stepwise with disease severity (compensated cirrhosis: 0.3 (0.2-0.4); AD without acute-on-chronic liver failure (ACLF): 1.9 (1.3-4.8); ACLF-1: 2.3 (1.8-6.1); ACLF-2: 5.6 (2.9-12.3); ACLF-3: 10.3 (5.7-17.2) ng/ml). From the multivariate Cox regression analysis, HNP1-3 emerged as independent predictors of mortality at 30 and 90 days. Similar results were observed in the subgroup analysis. On ROC analysis, plasma HNP1-3 showed better predictive accuracy for 30- and 90-day mortality (area under the receiver operating characteristic (AUROC) of 0.850 and 0.885, respectively) than the neutrophil-to-lymphocyte ratio (NLR) and similar accuracy as end-stage liver disease (MELD: 0.881 and 0.874) and chronic liver failure-sequential organ failure (CLIF-SOFA: 0.887 and 0.878).

CONCLUSIONS

Plasma HNP1-3 levels were closely associated with disease severity and might be used to identify patients with AD at high risk of short-term mortality.

Advances in immunotherapy modalities for atherosclerosis

Cardiovascular disease (CVD) is one of the leading causes of death worldwide. Atherosclerosis is the pathological basis of atherosclerotic cardiovascular disease (ASCVD). Atherosclerosis is now understood to be a long-term immune-mediated inflammatory condition brought on by a complicated chain of factors, including endothelial dysfunction, lipid deposits in the artery wall, and monocyte-derived macrophage infiltration, in which both innate immunity and adaptive immunity play an indispensable role. Recent studies have shown that atherosclerosis can be alleviated by inducing a protective immune response through certain auto-antigens or exogenous antigens. Some clinical trials have also demonstrated that atherosclerotic is associated with the presence of immune cells and immune factors in the body. Therefore, immunotherapy is expected to be a new preventive and curative measure for atherosclerosis. In this review, we provide a summary overview of recent progress in the research of immune mechanisms of atherosclerosis and targeted therapeutic pathways.

Human Neutrophil Defensins Disrupt Liver Interendothelial Junctions and Aggravate Sepsis

Human neutrophil peptides 1-3 (HNP1-3), also known as human α-defensins, are the most abundant neutrophil granule proteins. The genes that encode HNP1-3, DEFA1/DEFA3, exhibit extensive copy number variations, which correlate well with their protein levels. Human and mouse studies have shown that increased copy numbers of DEFA1/DEFA3 worsen sepsis outcomes. Additionally, high concentrations of HNP1-3 in body fluids have been reported in patients with sepsis. However, direct evidence for the pathogenic role of HNP1-3 proteins during sepsis progression is lacking. In current study, sepsis was induced by means of cecal puncture and ligation. Various doses of HNP-1 (low dose with 0.5 mg/kg body weight and high dose with 10 mg/kg body weight) or phosphate buffer saline were intraperitoneally administered to mice at six hours after sepsis onset. Survival rate was monitored, and vascular permeability, endothelial cell pyroptosis, and immunofluorescence of endothelial adherens junction protein vascular endothelial-cadherin were evaluated. The administration of a high dose of HNP-1 after sepsis onset led to increased mortality, more severe liver injury, and increased vascular permeability in the liver and mesentery. The injection of high dose of HNP-1 did not directly induce liver endothelial cell death but destroyed interendothelial junctions in the liver. Moreover, genetic deficiency of nucleotide-binding oligomerization domain-like receptor protein-3 or caspase-1 abrogated the high mortality and disrupted liver interendothelial junctions caused by high dose of HNP-1 during sepsis. This study directly demonstrates that neutrophil defensins play a key role in regulating endothelial stability during sepsis development.

PPBP gene as a biomarker for coronary heart disease risk in postmenopausal Thai women

Background

Estrogen is an important ovarian hormone with anti-atherogenic and cardioprotective effects. Postmenopausal women have lower estrogen levels, associated with significantly higher risks of coronary heart disease (CHD) and CHD-related death. Effective biomarkers for the diagnosis, prediction, and treatment of CHD are needed to address this problem and thus reduce the mortality due to CHD in postmenopausal women. We recently reported that the PPBP and DEFA1/DEFA3 genes may be feasible synergistic biomarkers for CHD risk in Thai men with hyperlipidemia. The PPBP gene encodes pro-platelet basic protein (PPBP) from activated platelets, and DEFA1/DEFA3 encodes human neutrophil peptides (HNP) 1-3, mainly produced by activated neutrophils. Both platelets and neutrophils are involved in chronic inflammation during the development of atherogenesis and CHD. This study investigated the potential roles of PPBP and DEFA1/DEFA3 and their proteins as biomarkers for CHD risk in postmenopausal Thai women.

Methods

This cross-sectional study enrolled 90 postmenopausal Thai women, including 12 healthy controls (N), 18 patients with hyperlipidemia (H), and 21 patients diagnosed with CHD. The remaining 39 women were receiving cholesterol-lowering drugs for hyperlipidemia (HD) were excluded from the study. All CHD patients underwent coronary bypass grafting or coronary angioplasty. PPBP and DEFA1/DEFA3 mRNA expression levels in peripheral blood mononuclear cells isolated from heparinized blood were determined by quantitative reverse-transcription polymerase chain reaction. Levels of PPBP and HNP-1-3 proteins in corresponding plasma samples were assessed by enzyme-linked immunosorbent assay. Differences in parameters were compared among groups and correlations between parameters and clinical manifestations were analyzed.

Results

PPBP mRNA and protein levels were significantly increased in the CHD group compared with the N and H groups. In contrast, DEFA1/DEFA3 mRNA and HNP-1-3 protein levels did not differ significantly among the groups. None of the levels were associated with any of the clinical parameters analyzed in this study.

Conclusion

The results indicate that gene and protein expression levels of PPBP, but not DEFA1/DEFA3, and HNP-1-3, may be feasible biomarkers for assessing CHD risk in postmenopausal Thai women with hyperlipidemia.

Effect of Anti-Rheumatic Drugs on Cardiovascular Disease Events in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disease characterized by erosive arthritis, which can involve multiple systems. Patients with RA may have a variety of comorbidities, including cardiovascular disease (CVD), lung cancer, lymphoma, infection, osteoporosis, fatigue, depression, colon cancer, breast cancer, prostate cancer, and Alzheimer's disease. Among these comorbidities, the incidence of CVD, lung cancer, lymphoma, infection, and osteoporosis is higher. CVD is a serious complication of RA. The risk of CVD and associated mortality rate in patients with RA is high, and the treatment rate is low. In addition to traditional risk factors, such as age, sex, blood pressure, and diabetes, RA is also associated with inflammation. Furthermore, therapeutic drugs for RA, including non-steroidal anti-inflammatory drugs, glucocorticoids, and disease-modifying anti-rheumatic drugs, have beneficial or harmful effects on cardiovascular events in patients with RA. This article discusses the effects of therapeutic drugs for RA on cardiovascular events.

Soluble Tumor Necrosis Factor Receptor 1 is Associated With Cardiovascular Risk in Persons With Coronary Artery Calcium Score of Zero

Background:

A coronary artery calcium (CAC) score of zero confers a low but nonzero risk of atherosclerotic cardiovascular events (CVD) in asymptomatic patient populations, and additional risk stratification is needed to guide preventive interventions. Soluble tumor necrosis factor receptors (sTNFR-1 and sTNFR-2) are shed in the context of TNF-alpha signaling and systemic inflammation, which play a role in atherosclerosis and plaque instability. We hypothesized that serum sTNFR-1 concentrations may aid in cardiovascular risk stratification among asymptomatic patients with a CAC score of zero.

Methods:

We included all participants with CAC=0 and baseline sTNFR-1 measurements from the prospective cohort Multi-Ethnic Study of Atherosclerosis (MESA). The primary outcome was a composite CVD event (myocardial infarction, stroke, coronary revascularization, cardiovascular death).

Results:

The study included 1471 participants (mean age 57.6 years, 64% female), with measured baseline sTNFR-1 ranging from 603 pg/mL to 5544 pg/mL (mean 1294 pg/mL ±378.8 pg/mL). Over a median follow-up of 8.5 years, 37 participants (2.5%) experienced a CVD event. In multivariable analyses adjusted for Framingham Score, doubling of sTNFR-1 was associated with a 3-fold increase in the hazards of CVD (HR 3.0, 95% CI: 1.48-6.09, P = 0.002), which remained significant after adjusting for traditional CVD risk factors individually (HR 2.29; 95% CI: 1.04-5.06, P=0.04). Doubling of sTNFR-1 was also associated with progression of CAC >100, adjusted for age (OR 2.84, 95% CI: 1.33-6.03, P=0.007).

Conclusions:

sTNFR-1 concentrations are associated with more CVD events in participants with a CAC score of zero. Utilizing sTNFR-1 measurements may improve cardiovascular risk stratification and guide primary prevention in otherwise low-risk individuals.

Immunotherapy of multisystem inflammatory syndrome in children (MIS-C) following COVID-19 through mesenchymal stem cells

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new type of coronavirus causing coronavirus 2019 (COVID-19) that was first observed in Wuhan, China, in Dec. 2019. An inflammatory immune response targeting children appeared during the pandemic, which was associated with COVID-19 named multisystem inflammatory syndrome in children (MIS-C). Characteristics of MIS-C include the classic inflammation findings, multi-organ dysfunction, and fever as the cardinal feature. Up to now, no specific therapy has been identified for MIS-C. Currently, considerable progress has been obtained in the MIS-C treatment by cell therapy, specially Mesenchymal stem cells (MSCs). Unique properties have been reported for MSCs, such as various resources for purification of cell, high proliferation, self-renewal, non-invasive procedure, tissue regenerator, multidirectional differentiation, and immunosuppression. As indicated by a recent clinical research, MSCs have the ability of reducing disease inflammation and severity in children with MIS-C. In the present review study, the benefits and characteristics of MSCs and exosomes are discussed for treating patients with MIS-C.

Human neutrophil peptide (HNP) in deteriorate sepsis patients

OBJECTIVE

The objective of this study was analyzed HNP1 and HNP3 level of deteriorating sepsis patients.

METHODS

It was a cross-sectional study that observed HNP and sepsis level, samples size were 40 patients taken by consecutive random sampling. Analysis of HNP serum level use enzyme-linked immunosorbent assay (ELISA), data analyzed used independent T-test and presented in tables with mean, standard deviation, mean difference and probability value.

RESULTS

Results show that when patients become deteriorate or shock sepsis, HNP1 levels increase dramatically, which is 356.2pg/ml higher than sepsis patients and statistically significant (p=0.016, p≤0.05). It is similar to HNP3 level, which is 2.04ng/ml higher than with sepsis patients and statistically significant (p=0.021, p≤0.05).

CONCLUSION

This study reveals that HNP1 and HNP3 level increases dramatically in deteriorate sepsis patients. Level of HNP1 and HNP3 of sepsis patient is higher than nonsepsis patient, shock sepsis patient is higher than sepsis patient and both HNP1 and HNP3 level is higher in die patient compare to alive patient.

Neutrophil: An emerging player in the occurrence and progression of metabolic associated fatty liver disease

Metabolic-associated fatty liver disease (MAFLD) is a common type of chronic liver disease characterized by excessive lipid accumulation in hepatocytes, but the pathogenesis is still unclear. Neutrophils, the most abundant immune cells in the human body, defend against pathogens and regulate the inflammatory response. Recent studies have indicated that excessive liver infiltration of neutrophils is a significant histological hallmark of MAFLD, and neutrophils and their derived granule proteins participate in different stages of MAFLD, including hepatic steatosis, inflammation, fibrosis, cirrhosis and hepatocellular carcinoma. Hence, in this review, we summarize the role of neutrophils in the occurrence and progression of MAFLD and provide a perspective for the clinical application of neutrophils in MAFLD diagnosis and treatment.

Kynurenic Acid Analog Attenuates the Production of Tumor Necrosis Factor-α, Calgranulins (S100A 8/9 and S100A 12), and the Secretion of HNP1-3 and Stimulates the Production of Tumor Necrosis Factor-Stimulated Gene-6 in Whole Blood Cultures of Patients With Rheumatoid Arthritis

Objectives: Rheumatoid arthritis (RA) is a chronic, inflammatory joint disease with complex pathogenesis involving a variety of immunological events. Recently, it has been suggested that kynurenic acid (KYNA) might be a potential regulator of inflammatory processes in arthritis. KYNA has a definitive anti-inflammatory and immunosuppressive function. The aim of the present study is to investigate the complex effects of a newly synthesized KYNA analog—SZR72 on the in vitro production of tumor necrosis factor-α (TNF-α), tumor necrosis factor-stimulated gene-6 (TSG-6), calprotectin (SA1008/9), SA100 12 (EN-RAGE), and HNP1–3 (defensin-α) in the peripheral blood of patients with RA and the various effects of the disease.

Methods: Patients with RA (n = 93) were selected based on the DAS28 score, medication, and their rheumatoid factor (RF) status, respectively. Peripheral blood samples from 93 patients with RA and 50 controls were obtained, and activated by heat-inactivated S. aureus. Parallel samples were pretreated before the activation with the KYNA analog N-(2-N, N-dimethylaminoethyl)-4-oxo-1H-quinoline-2-carboxamide hydrochloride. Following the incubation period (18 h), the supernatants were tested for TNF-α, TSG-6, calprotectin, S100A12, and HNP1–3 content by ELISA.

Results: SZR72 inhibited the production of the following inflammatory mediators: TNF-α, calprotectin, S100A12, and HNP1–3 in whole blood cultures. This effect was observed in each group of patients in various phases of the disease. The basic (control) levels of these mediators were higher in the blood of patients than in healthy donors. In contrast, lower TSG-6 levels were detected in patients with RA compared to healthy controls. In addition, the KYNA analog exerted a stimulatory effect on the TSG-6 production ex vivo in human whole blood cultures of patients with RA in various phases of the disease.

Conclusion: These data further support the immunomodulatory role of KYNA in RA resulting in anti-inflammatory effects and draw the attention to the importance of the synthesis of the KYNA analog, which might have a future therapeutic potential.

Immunomodulatory and Regenerative Effects of Mesenchymal Stem Cells and Extracellular Vesicles: Therapeutic Outlook for Inflammatory and Degenerative Diseases

Mesenchymal stem cells (MSCs) are non-hematopoietic, multipotent stem cells derived from mesoderm, which can be easily isolated from many sources such as bone marrow, umbilical cord or adipose tissue. MSCs provide support for hematopoietic stem cells and have an ability to differentiate into multiple cell lines. Moreover, they have proangiogenic, protective and immunomodulatory properties. MSCs have the capacity to modulate both innate and adaptive immune responses, which accompany many diseases, by inhibiting pro-inflammatory reactions and stimulating anti-inflammatory activity. Recent findings revealed that the positive effect of MSCs is at least partly associated with the production of extracellular vesicles (EVs). EVs are small membrane structures, containing proteins, lipids and nuclei acids, which take part in intra-cellular communication. Many studies indicate that EVs contain protective and pro-regenerative properties and can modulate an immune response that is activated in various diseases such as CNS diseases, myocardial infarction, liver injury, lung diseases, ulcerative colitis or kidney injury. Thus, EVs have similar functions as their cells of origin and since they do not carry the risk of cell transplantation, such as tumor formation or small vessel blockage, they can be considered a potential therapeutic tool for cell-free therapy.

Insights Into Immunothrombosis: The Interplay Among Neutrophil Extracellular Trap, von Willebrand Factor, and ADAMTS13

Both neutrophil extracellular traps (NETs) and von Willebrand factor (VWF) are essential for thrombosis and inflammation. During these processes, a complex series of events, including endothelial activation, NET formation, VWF secretion, and blood cell adhesion, aggregation and activation, occurs in an ordered manner in the vasculature. The adhesive activity of VWF multimers is regulated by a specific metalloprotease ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motifs, member 13). Increasing evidence indicates that the interaction between NETs and VWF contributes to arterial and venous thrombosis as well as inflammation. Furthermore, contents released from activated neutrophils or NETs induce the reduction of ADAMTS13 activity, which may occur in both thrombotic microangiopathies (TMAs) and acute ischemic stroke (AIS). Recently, NET is considered as a driver of endothelial damage and immunothrombosis in COVID-19. In addition, the levels of VWF and ADAMTS13 can predict the mortality of COVID-19. In this review, we summarize the biological characteristics and interactions of NETs, VWF, and ADAMTS13, and discuss their roles in TMAs, AIS, and COVID-19. Targeting the NET-VWF axis may be a novel therapeutic strategy for inflammation-associated TMAs, AIS, and COVID-19.

The significance of α-defensins 1-3 in Behcet’s disease: a case-control study among Egyptian patients

Background

Behcet’s disease (BD) is associated with uveitis, oral ulcers, genital ulcers and arthritis. Enhanced activity of innate immunity components, such as neutrophils, natural killer (NK) cells and endothelial cells, is a prominent feature of BD. The aim of this study was to clarify the significance of α-defensins 1-3 in BD and detect their correlation with disease activity, severity and oral ulcer activity.

Results

Significant differences were found between Behcet’s patients and controls as regards serum α-defensins 1-3 (median 10.1, IQR 4–45 μg/ml versus median 7.4, IQR 0.6–13.2 μg/ml, p = 0.001) and salivary α-defensins 1-3 (median 17.4, IQR 5.7–44 μg/ml versus median 8.6, IQR 3.3–11 μg/ml, p < 0.001). Receiver operating characteristic (ROC) showed a fair area under curve (AUC) (AUC = 0.743), with sensitivity of 40% and specificity 100% at cutoff value of 17.3 μg/ml for serum α-defensins 1-3, while salivary α-defensins 1-3 showed excellent AUC (AUC = 0.936), with sensitivity of 93.3% and specificity of 86.7% at cutoff value of 9.8 μg/ml. The levels of serum and salivary α-defensins 1-3 > cutoff value were significantly higher in active severe Behcet’s patients with active oral ulcers (p < 0.001).

Conclusion

α-Defensins 1-3 may be involved in the pathogenesis of BD and could be valuable markers in the determination of disease activity, severity and oral ulcer activity.

Prospective evaluation of vascular changes in acute respiratory infections in children with cystic fibrosis

Background/aim

Acute exacerbations and chronic inflammation are risk factors for cardiovascular disease (CVD) in cystic fibrosis (CF) patients. The aim of this study was to investigate the effects of acute exacerbation therapy on arterial stiffness in children with CF.

Materials and methods

Augmentation index (Aix) and pulse wave velocity (PWV) were measured before and after treatment and 1 month after the end of treatment in patients with acute exacerbation. The relationship between hemodynamic measurements and c-reactive protein (CRP) and pulmonary function tests (PFTs) was investigated.

Results

Measurements before and after treatment were evaluated in 27 patients and were repeated in 21 patients who were clinically stable 1 month following acute exacerbation. There was a significant decrease in CRP and an increase in spirometry parameters after treatment. While no significant difference was found between PWV (P = 0.33), a significant difference for Aix before (41.95 ± 12.96%) and after (30.95 ± 11.47%) treatment and before treatment and stable clinical condition (34.19 ± 14.36%) was obtained (P =0.00, and P =0.01, respectively). No significant difference in heart rate and other hemodynamic measurements was found. Pretreatment Aix is associated with poor clinical condition (PFTs, BMI, and clinical score) and systemic inflammation (CRP) (P <0.05).

Conclusion

The decrease of arterial stiffness (Aix) with acute exacerbation treatment in children with CF has been demonstrated. This result shows that systemic inflammation in CF may cause an increase in arterial stiffness and recurrent exacerbations may increase the risk of CVD.

PR3 levels are impaired in plasma and PBMCs from Arabs with cardiovascular diseases

Cardiovascular disease (CVD) risks persist in patients despite treatment. CVD susceptibility also varies with sex and ethnicity and is not entirely explained by conventional CVD risk factors. The aim of the present study was to identify novel CVD candidate markers in circulating Peripheral blood mononuclear cells (PBMCs) and plasma from Arab obese subjects with and without CVD using proteomic approaches. Human adults with confirmed CVD (n = 208) and matched non-CVD controls (n = 152) living in Kuwait were examined in the present cross-sectional study. Anthropometric and classical biochemical parameters were determined. We employed a shotgun proteomic profiling approach on PBMCs isolated from a subset of the groups (n = 4, each), and differentially expressed proteins selected between the two groups were validated at the mRNA level using RT-PCR (n = 6, each). Plasma levels of selected proteins from the proteomics profiling: Proteinase-3 (PR3), Annexin-A3 (ANX3), Defensin (DEFA1), and Matrix Metalloproteinase-9 (MMP9), were measured in the entire cohort using human enzyme-linked immunosorbent assay kits and were subsequently correlated with various clinical parameters. Out of the 1407 we identified and quantified from the proteomics profiling, 47 proteins were dysregulated with at least twofold change between the two subject groups. Among the differentially expressed proteins, 11 were confirmed at the mRNA levels. CVD influenced the levels of the shortlisted proteins (MMP9, PR3, ANX3, and DEFA1) in the PBMCs and plasma differentially. Despite the decreased levels of both protein and mRNA in PBMCs, PR3 circulating levels increased significantly in patients with CVD and were influenced by neither diabetes nor statin treatment. No significant changes were; however, observed in the DEFA1, MMP9, and ANX3 levels in plasma. Multivariate logistic regression analysis revealed that only PR3 was independently associated with CVD. Our results suggest that the dysregulation of PR3 levels in plasma and PBMCs reflects underlying residual CVD risks even in the treated population. More prospective and larger studies are required to establish the role of PR3 in CVD progression.

Modulation of Human Neutrophil Peptides on P. aeruginosa Killing, Epithelial Cell Inflammation and Mesenchymal Stromal Cell Secretome Profiles

Objective

Neutrophil infiltration and release of the abundant human neutrophil peptides (HNP) are a common clinical feature in critically ill patients. We tested a hypothesis that different cell types respond to HNP differently in lung microenvironment that may influence the host responses.

Methods

Plasma concentrations of HNP were measured in healthy volunteers and patients with sepsis. Cells including the bacteria P. aeruginosa, human lung epithelial cells and mesenchymal stromal cells (MSCs) were exposed to various concentrations of HNP. Bacterial killing, epithelial cell inflammation, MSC adhesion and behaviours were examined after HNP stimulation.

Results

Incubation of P. aeruginosa or stimulation of human lung epithelial cells with HNP resulted in bacterial killing or IL-8 production at a dose of 50 μg/mL, while MSC adhesion and alternations of secretome profiles took place after HNP stimulation at a dose of 10 μg/mL. The secretome profile changes were characterized by increased release of the IL-6 family members such as C-reactive protein (CRP), leukemia inhibitory factor (LIF) and interleukin (IL-11), and first apoptosis signal (FAS) and platelet-derived growth factor-AA as compared to a vehicle control group.

Conclusion

Stimulation of MSCs with HNP resulted in changes of secretome profiles at 5-fold lower concentration than that required for bacterial killing and lung epithelial inflammation. This undisclosed risk factor of HNP in lung environment should be taken into consideration when MSCs are applied as cell therapy in inflammatory lung diseases.

Human neutrophil peptide-1 inhibits thrombus formation under arterial flow via its terminal free cysteine thiols

Essentials Biological activity of human neutrophil peptide (HNP)-1 in hemostasis under physiological conditions is not fully understood. HNP-1 inhibits the adhesion/aggregation of murine platelets on a fibrillar collagen surface or an activated endothelial cell surface under flow. The anti-adhesion activity appears to depend on the terminal free thiols of HNP-1, which may inhibit VWF-VWF lateral associations. Our results suggest a protective role and potential novel therapeutic use of HNP-1 for arterial thrombosis. SUMMARY: Background Human neutrophil peptides (HNPs), also known as α-defensins, are released from degranulated neutrophils and play an important role in innate immunity. However, their biological roles in hemostasis under flow are not fully explored. Objective This study aims to determine the role of HNP-1 on platelet adhesion and aggregation on a collagen surface or ultra large von Willebrand factor (ULVWF) on endothelium under flow and elucidate the structural elements required for its activity. Methods Anticoagulated whole blood from wild-type or Adamts13-/- mice was incubated with a fluorescein-conjugated anti-human CD41 in the presence of increasing concentrations of a synthetic HNP-1 and perfused over a collagen surface or a tumor necrosis factor (TNF)-α activated murine endothelial cell surface under arterial flow. The rate of accumulation and the final surface coverage of fluoresceinated murine platelets or the rate of forming platelet-decorated ULVWF strings were determined using the BioFlux microfluidic system. Results HNP-1 inhibited the rate and final coverage of fluorescein-labeled murine platelets on a fibrillar collagen surface under flow (100 dyne/cm2 ) in a concentration-dependent manner and the anti-adhesive activity of HNP-1 depended on its terminal free cysteine thiols. HNP-1 (20 μM) also dramatically inhibited the formation of platelets-decorated ULVWF strings on TNF-α activated murine endothelial surface under arterial flow. Conclusions Our results demonstrate for the first time an antiplatelet adhesion or antithrombotic activity of HNP-1; this activity depends on its terminal free thiols, likely affecting VWF-VWF lateral associations. These findings may suggest a potential novel therapeutic strategy for arterial thrombosis.

Newly Identified HNP-F from Human Neutrophil Peptide-1 Promotes Hemostasis

Active hemostatic agents can play a crucial role in saving patients' lives during surgery. Active hemostats have several advantages including utilization of natural blood coagulation and biocompatibility. Among them, although human neutrophil peptide-1 (HNP-1) has been previously reported with the hemostatic mechanism, which part of HNP-1 facilitates the hemostatic activity is not known. Here, a partial peptide (HNP-F) promoting hemostasis, originating from HNP-1, has been newly identified by the blood coagulation ability test. HNP-F shows the best hemostatic effect between the anterior half and posterior half of peptides. Moreover, microscopic images show platelet aggregation and an increase in the concentration of platelet factor 4, and the scanning electron microscope image of platelets support platelet activation by HNP-F. Thromboelastography indicates decreased clotting time and increased physical properties of blood clotting. Mouse liver experiments demonstrate improved hemostatic effect by treatment of peptide solution. Cell viability and hemolysis assays confirm the HNP-F's biosafety. It is hypothesized that the surface charge and structure of HNP-F could be favorable to interact with fibrinogen or thrombospondin-1. Collectively, because HNP-F as an active peptide hemostat has many advantages, it could be expected to become a potent hemostatic biomaterial, additive or pharmaceutical candidate for various hemostatic applications.

Dual specificity phosphatase DUSP6 promotes endothelial inflammation through inducible expression of ICAM-1

Tumor necrosis factor (TNF)-α activates a diverse array of signaling pathways in vascular endothelial cells (ECs), leading to the inflammatory phenotype that contributes to the vascular dysfunction and neutrophil emigration in patients with sepsis. To date, it is not well understood what key regulator might coordinate signaling pathways to achieve inflammatory response in TNF-α-stimulated ECs. This study investigated the role of dual specificity phosphatase-6 (DUSP6) in the regulation of endothelial inflammation. Using knockout mice, we found that DUSP6 is important for TNF-α-induced endothelial intercellular adhesion molecule-1 (ICAM-1) expression in aorta and in vein. Moreover, genetic deletion of Dusp6 in pulmonary circulation significantly alleviated the susceptibility of mice to lung injury caused by neutrophil recruitment during experimental sepsis induced by TNF-α or lipopolysaccharide (LPS). The role of DUSP6 was further investigated in primary human umbilical vein endothelial cells (HUVECs). Employing RNAi approach in which endogenous DUSP6 was ablated, we showed a critical function of DUSP6 to facilitate TNF-α-induced ICAM-1 expression and endothelial leukocyte interaction. Interestingly, DUSP6-promoted endothelial inflammation is independent of extracellular signaling-regulated kinase (ERK) signaling. On the other hand, inducible DUSP6 leads to activation of canonical nuclear factor (NF)-κB-mediated transcription of ICAM-1 gene in TNF-α-stimulated human ECs. These results are the first to demonstrate a positive role of DUSP6 in endothelial inflammation-mediated pathological process and the underlying mechanism through which DUSP6 promotes NF-κB signaling in the inflamed ECs. Our findings suggest that manipulation of DUSP6 holds great potential for the treatment of acute inflammatory diseases.

Neutrophilic granulocytes – promiscuous accelerators of atherosclerosis

Neutrophils, as part of the innate immune system, are classically described to be main actors during the onset of inflammation enforcing rapid neutralisation and clearance of pathogens. Besides their wellstudied role in acute inflammatory processes, recent advances strongly indicate a so far underappreciated importance of neutrophils in initiation and development of atherosclerosis. This review focuses on current findings on the role of neutrophils in atherosclerosis. As pro-inflammatory mechanisms of neutrophils have primarily been studied in the microvascular environment; we here aim at translating these into the context of macrovascular inflammation in atherosclerosis. Since much of the pro-inflammatory activities of neutrophils stem from instructing neighbouring cell types, we highlight the promiscuous interplay between neutrophils and platelets, monocytes, T lymphocytes, and dendritic cells and its possible relevance to atherosclerosis.

The correlation between plasma human neutrophil peptide 1-3 levels and severity of coronary artery disease

Introduction

Inflammation plays a key role in atherosclerosis, and discovering new biomarkers of inflammation is becoming important in order to uncover the pathogenesis of atherosclerotic coronary artery disease (CAD). Recent studies have focused on polymorphonuclear neutrophils. It has been suggested that human neutrophil peptide 1-3 (HNP1-3) is proatherogenic. In this study, we aimed to investigate the associations between plasma HNP1-3 levels and the severity of atherosclerosis via a generally accepted scoring system.

Material and methods

This cross-sectional, observational study included 107 consecutive patients suffering from stable angina pectoris and undergoing coronary angiography (CAG). Patients were divided into two groups according to the Gensini scoring (GS) system evaluating disease severity. Group 1 was composed of mild CAD patients with GS < 20 and group 2 consisted of severe CAD patients with GS ≥ 20. Plasma HNP1-3 levels were assessed by the ELISA method.

Results

The mean HNP1-3 levels were found to be lower in group 1 than group 2 (134.7 ng/ml vs. 147.5 ng/ml). HNP1-3 levels were significantly higher in the severe CAD group than the mild CAD group according to GS (p < 0.001). The results of multivariate logistic regression analysis revealed that only age > 62 years and HNP1-3 > 134 ng/ml were independent predictors of the severity of CAD after adjusting for gender, smoking, hypertension, hyperlipidemia, diabetes, family history of CAD and white blood cell count. In predicting the severity of CAD, the sensitivity and specificity of HNP1-3 were 83.9% (p < 0.001) and 58.8% (p < 0.001), respectively.

Conclusions

This study revealed that the plasma levels of HNP1-3 were significantly higher in severe CAD than mild CAD.

The Role of von Willebrand Factor in Vascular Inflammation: From Pathogenesis to Targeted Therapy

Beyond its role in hemostasis, von Willebrand factor (VWF) is an emerging mediator of vascular inflammation. Recent studies highlight the involvement of VWF and its regulator, ADAMTS13, in mechanisms that underlie vascular inflammation and immunothrombosis, like leukocyte rolling, adhesion, and extravasation; vascular permeability; ischemia/reperfusion injury; complements activation; and NETosis. The VWF/ADAMTS13 axis is implicated in the pathogenesis of atherosclerosis, promoting plaque formation and inflammation through macrophage and neutrophil recruitment in inflamed lesions. Moreover, VWF and ADAMTS13 have been recently proposed as prognostic biomarkers in cardiovascular, metabolic, and inflammatory diseases, such as diabetes, stroke, myocardial infarction, and sepsis. All these features make VWF an attractive therapeutic target in thromboinflammation. Several lines of research have recently investigated “tailor-made” inhibitors of VWF. Results from animal models and clinical studies support the potent anti-inflammatory and antithrombotic effect of VWF antagonism, providing reassuring data on its safety profile. This review describes the role of VWF in vascular inflammation “from bench to bedside” and provides an updated overview of the drugs that can directly interfere with the VWF/ADAMTS13 axis.

Presepsin (sCD14-ST): could it be a novel marker for the diagnosis of ST elevation myocardial infarction?

Introduction

Acute myocardial infarction (AMI) could be considered to be a state of inflammation. Many inflammatory markers have been evaluated in the AMI setting so far. Presepsin (PSP) is a novel biomarker for diagnosis and prognosis of systemic inflammation that has not been studied in the AMI setting to date. In this study, we aimed to examine serum PSP levels in patients with acute ST elevation myocardial infarction (STEMI).

Material and methods

Forty-eight patients with STEMI and fifty healthy controls without coronary artery disease, verified by coronary angiography, were included in the study. Together with routine laboratory tests needed for STEMI, plasma concentrations of PSP were measured in peripheral venous blood samples of the participants.

Results

Plasma PSP and troponin levels were significantly higher in patients with STEMI than controls (1988.89 ±3101.55 vs. 914.22 ±911.35 pg/ml, p = 0.001 and 3.46 ±3.39 vs. 0.08 ±0.43 ng/ml, p = 0.001, respectively). The cut-off value for PSP of 447 pg/ml was found to detect STEMI with 87.5% sensitivity, 44% specificity, 60% positive predictive value and 78.5% negative predictive value.

Conclusions

In this study, PSP levels were found to be significantly elevated in patients with STEMI together with high-sensitivity troponins. The PSP may be a new marker for AMI detection. Large scale studies are needed to reveal the importance of PSP in the diagnosis and prognosis of AMI.

Significance of Exhaled Breath Test in Clinical Diagnosis: A Special Focus on the Detection of Diabetes Mellitus

Analysis of volatile organic compounds (VOCs) emanating from human exhaled breath can provide deep insight into the status of various biochemical processes in the human body. VOCs can serve as potential biomarkers of physiological and pathophysiological conditions related to several diseases. Breath VOC analysis, a noninvasive and quick biomonitoring approach, also has potential for the early detection and progress monitoring of several diseases. This paper gives an overview of the major VOCs present in human exhaled breath, possible biochemical pathways of breath VOC generation, diagnostic importance of their analysis, and analytical techniques used in the breath test. Breath analysis relating to diabetes mellitus and its characteristic breath biomarkers is focused on. Finally, some challenges and limitations of the breath test are discussed.

Human neutrophil peptides and complement factor Bb in pathogenesis of acquired thrombotic thrombocytopenic purpura

Acquired thrombotic thrombocytopenic purpura is primarily caused by the deficiency of plasma ADAMTS13 activity resulting from autoantibodies against ADAMTS13. However, ADAMTS13 deficiency alone is often not sufficient to cause acute thrombotic thrombocytopenic purpura. Infections or systemic inflammation may precede acute bursts of the disease, but the underlying mechanisms are not fully understood. Herein, 52 patients with acquired autoimmune thrombotic thrombocytopenic purpura and 30 blood donor controls were recruited for the study. The plasma levels of human neutrophil peptides 1-3 and complement activation fragments (i.e. Bb, iC3b, C4d, and sC5b-9) were determined by enzyme-linked immunosorbent assays. Univariate analyses were performed to determine the correlation between each biomarker and clinical outcomes. We found that the plasma levels of human neutrophil peptides 1-3 and Bb in patients with acute thrombotic thrombocytopenic purpura were significantly higher than those in the control (P<0.0001). The plasma levels of HNP1-3 correlated with the levels of plasma complement fragment Bb (rho=0.48, P=0.0004) and serum lactate dehydrogenase (rho=0.28, P=0.04); in addition, the plasma levels of Bb correlated with iC3b (rho=0.55, P<0.0001), sC5b-9 (rho=0.63, P<0.0001), serum creatinine (rho=0.42, p=0.0011), and lactate dehydrogenase (rho=0.40, P=0.0034), respectively. Moreover, the plasma levels of iC3b and sC5b-9 were correlated (rho=0.72, P<0.0001), despite no statistically significant difference of the two markers between thrombotic thrombocytopenic purpura patients and the control. We conclude that innate immunity, i.e. neutrophil and complement activation via the alternative pathway, may play a role in the pathogenesis of acute autoimmune thrombotic thrombocytopenic purpura, and a therapy targeted at these pathways may be considered in a subset of these patients.

Dynamics of early stem cell recruitment in skin flaps subjected to ischemia reperfusion injury

OBJECTIVE

Bone marrow-derived stromal cell (BMSCs) therapy improves survival of skin flaps subject to ischemia/reperfusion (I/R) injury. However, very little is known about the trafficking and distribution of BMSCs in post-ischemic skin tissue following intravenous administration. The aim of this study was to assess the behavior of BMSCs in post-ischemic skin flaps and to compare the magnitude and kinetics of accumulation of BMSCs and leukocytes following I/R.

METHODS

Cutaneous flaps perfused by the inferior epigastric vessels were created in C57Bl6 mice. The flaps were subjected to 3.5h of ischemia followed by reperfusion. Wound healing and vascular perfusion were assessed in 3 groups of mice (sham, I/R, and I/R+BMSCs treatment) on days 3, 5, 7 and 14 post-reperfusion. The kinetics and magnitude of BMSCs and leukocyte recruitment were quantified in additional 2 groups (Sham and I/R) after I/R using intravital fluorescence microscopy at 2 and 4h after the intravenous injection of fluorescently labeled BMSCs.

RESULTS

Wound healing after I/R was significantly enhanced in skin flaps of mice treated with BMSCs, compared to controls. The rolling velocity of BMSCs was higher compared to leukocytes both in control mice (32.4±3.7μm/s vs 24.0±2.2μm/s, p<0.05) and in I/R mice (34.6±3.8μm/s vs 20.2±2.3μm/s, p<0.005). However, the rolling velocity of both cell populations was not altered by I/R. The firm adhesion and transendothelial migration of BMSCs did not differ from the values detected for leukocytes for both control and I/R mice.

CONCLUSIONS

The magnitude and kinetics of BMSCs recruitment in skin flaps subjected to I/R are not significantly different from the responses noted for leukocytes, suggesting that similar mechanisms may be involved in the recruitment of both cell populations following I/R.

Increased alpha-defensin expression is associated with risk of coronary heart disease: a feasible predictive inflammatory biomarker of coronary heart disease in hyperlipidemia patients

Background

Atherosclerosis is a multifactorial disorder of the heart vessels that develops over decades, coupling inflammatory mechanisms and elevated total cholesterol levels under the influence of genetic and environmental factors. Without effective intervention, atherosclerosis consequently causes coronary heart disease (CHD), which leads to increased risk of sudden death.

Polymorphonuclear neutrophils play a pivotal role in inflammation and atherogenesis. Human neutrophil peptides (HNPs) or alpha (α)-defensins are cysteine-rich cation polypeptides that are produced and released from activated polymorphonuclear neutrophil granules during septic inflammation and acute coronary vascular disorders. HNPs cause endothelial cell dysfunction during early atherogenesis. In this cross-sectional study, control, hyperlipidemia and CHD groups were representative as atherosclerosis development and CHD complications. We aimed to assess the correlation between α-defensin expression and the development of CHD, and whether it was a useful predictive indicator for CHD risk.

Methods

First, DNA microarray analysis was performed on peripheral blood mononuclear cells (PBMCs) from Thai control, hyperlipidemia and CHD male patients (n = 7). Gene expression profiling revealed eight up-regulated genes common between hyperlipidemia and CHD patients, but not controls. We sought to verify and compare α-defensin expression among the groups using: 1) real-time quantitative RT-PCR (qRT-PCR) to determine α-defensin mRNA expression (n = 10), and 2) enzyme-linked immunosorbent assay to determine plasma HNP 1–3 levels (n = 17). Statistically significant differences and correlations between groups were determined by the Mann–Whitney U test or the Kruskal–Wallis test, and the Rho-Spearman correlation, respectively.

Results

We found that α-defensin mRNA expression increased (mean 2-fold change) in the hyperlipidemia (p = 0.043) and CHD patients (p = 0.05) compared with the controls. CHD development moderately correlated with α-defensin mRNA expression (r = 0.429, p = 0.023) and with plasma HNP 1–3 levels (r = 0.486, p = 0.000).

Conclusions

Increased α-defensin expression is a potential inflammatory marker that may predict the risk of CHD development in Thai hyperlipidemia patients.

Human neutrophil peptides inhibit cleavage of von Willebrand factor by ADAMTS13: a potential link of inflammation to TTP

Infection or inflammation may precede and trigger formation of microvascular thrombosis in patients with acquired thrombotic thrombocytopenic purpura (TTP). However, the mechanism underlying this clinical observation is not fully understood. Here, we show that human neutrophil peptides (HNPs) released from activated and degranulated neutrophils inhibit proteolytic cleavage of von Willebrand factor (VWF) by ADAMTS13 in a concentration-dependent manner. Half-maximal inhibitory concentrations of native HNPs toward ADAMTS13-mediated proteolysis of peptidyl VWF73 and multimeric VWF are 3.5 μM and 45 μM, respectively. Inhibitory activity of HNPs depends on the RRY motif that is shared by the spacer domain of ADAMTS13. Native HNPs bind to VWF73 (KD = 0.72 μM), soluble VWF (KD = 0.58 μM), and ultra-large VWF on endothelial cells. Enzyme-linked immunosorbent assay (ELISA) demonstrates markedly increased plasma HNPs1-3 in most patients with acquired autoimmune TTP at presentation (median, ∼170 ng/mL; range, 58-3570; n = 19) compared with healthy controls (median, ∼23 ng/mL; range, 6-44; n = 18) (P < .0001). Liquid chromatography plus tandem mass spectrometry (LC-MS/MS) reveals statistically significant increases of HNP1, HNP2, and HNP3 in patient samples (all P values <.001). There is a good correlation between measurement of HNPs1-3 by ELISA and by LC-MS/MS (Spearman ρ = 0.7932, P < .0001). Together, these results demonstrate that HNPs1-3 may be potent inhibitors of ADAMTS13 activity, likely by binding to the central A2 domain of VWF and physically blocking ADAMTS13 binding. Our findings may provide a novel link between inflammation/infection and the onset of microvascular thrombosis in acquired TTP and potentially other immune thrombotic disorders.

Production of IL-8, VEGF and Elastase by Circulating and Intraplaque Neutrophils in Patients with Carotid Atherosclerosis

Objectives

Polymorphonuclear neutrophils (PMN) in atherosclerotic plaques have been identified only recently, and their contribution to plaque development is not yet fully understood. In this study, production of elastase, interleukin (IL)-8 and vascular endothelial growth factor (VEGF) by PMN was investigated in subjects with carotid stenosis undergoing carotid endarterectomy (CEA).

Methods

The study enrolled 50 patients (Pts) and 10 healthy subjects (HS). Circulating PMN (cPMN) isolated from venous blood (in both Pts and HS) and from plaques (pPMN, in Pts) were cultured, alone or with 0.1 μM fMLP. Elastase, IL-8 and VEGF mRNA were analyzed by real-time PCR. In CEA specimens, PMN were localized by immunohistochemistry.

Results

In both Pts cPMN and pPMN, IL-8 mRNA was higher at rest but lower after fMLP (P<0.01 vs HS), and VEGF mRNA was higher both at rest and after fMLP (P<0.01 vs HS), while elastase mRNA was not significantly different. On the contrary, protein production was always higher in cPMN of HS with respect to values measured in cells of Pts. In CEA specimens, CD66b+ cells localized to areas with massive plaque formation close to neovessels. Pts with soft and mix plaques, as defined by computed tomography, did not differ in cPMN or pPMN IL-8, VEGF or elastase mRNA, or in intraplaque CD66b+ cell density. However, Pts with soft plaques had higher white blood cell count due to increased PMN.

Conclusions

In Pts with carotid plaques, both circulating and intraplaque PMN produce IL-8, VEGF and elastase, which are crucial for plaque development and progression. These findings suggest mechanistic explanations to the reported correlation between PMN count and cardiovascular mortality in carotid ATH.

Inflammation, oxidative stress, and cardiovascular disease risk factors in adults with cystic fibrosis

Cystic fibrosis (CF) represents one of a number of localized lung and non-lung diseases with an intense chronic inflammatory component associated with evidence of systemic oxidative stress. Many of these chronic inflammatory diseases are accompanied by an array of atherosclerotic processes and cardiovascular disease (CVD), another condition strongly related to inflammation and oxidative stress. As a consequence of a dramatic increase in long-lived patients with CF in recent decades, the specter of CVD must be considered in these patients who are now reaching middle age and beyond. Buttressed by recent data documenting that CF patients exhibit evidence of endothelial dysfunction, a recognized precursor of atherosclerosis and CVD, the spectrum of risk factors for CVD in CF is reviewed here. Epidemiological data further characterizing the presence and extent of atherogenic processes in CF patients would seem important to obtain. Such studies should further inform and offer mechanistic insights into how other chronic inflammatory diseases potentiate the processes leading to CVDs.

Human neutrophil α-defensins are associated with adenosine diphosphate-inducible neutrophil-platelet aggregate formation and response to clopidogrel in patients with atherosclerosis

Human neutrophil α-defensins (HNPs) are antimicrobial peptides stored primarily in the azurophilic granules of polymorphonuclear leukocytes. Recently, it was shown that HNPs act as platelet agonists. We hypothesized that HNP levels are associated with the formation of neutrophil-platelet aggregates, and that they influence the response to clopidogrel therapy. HNP levels were determined by a commercially available enzyme-linked immunosorbent assay in 305 patients undergoing angioplasty and stenting for atherosclerotic cardiovascular disease. Neutrophil-platelet aggregates were measured by flow cytometry, and on-treatment platelet reactivity was determined using the VerifyNow P2Y12 and aspirin assays. HNP levels did not correlate with the formation of neutrophil-platelet aggregates in vivo (r = 0.05, P = 0.4). In contrast, HNP levels correlated significantly with adenosine diphosphate (ADP)-inducible neutrophil-platelet aggregate formation (r = 0.13, P = 0.04). On-treatment platelet reactivity by the VerifyNow P2Y12 assay was significantly more pronounced in patients with high HNP levels compared with patients with low HNP levels (211 P2Y12 reaction units [PRU; range, 143-293 PRU] vs 181 PRU [range, 129-237 PRU], P = 0.009). This association remained significant after adjusting for high-sensitivity C-reactive protein and interleukin 6 by multivariate regression analysis (P = 0.007). Moreover, high on-treatment residual platelet reactivity by the VerifyNow P2Y12 assay was more frequent in patients with high HNP levels than in patients with low HNP levels (40% vs 26.6%, P = 0.01). In conclusion, HNP levels are associated with ADP-inducible neutrophil-platelet aggregate formation and clopidogrel-mediated platelet inhibition. High levels of HNPs may, in part, be responsible for the observed response variability to clopidogrel.

Relevance of α-defensins (HNP1-3) and defensin β-1 in diabetes

AIM: To investigate the genetic background of human defensin expression in type 1 and 2 diabetes.

METHODS: Associations between DEFA1/DEFA3 gene copy number polymorphism and diabetes as well as between the promoter polymorphisms of DEFB1 and diabetes were studied. The copy number variation of the DEFA1/DEFA3 genes was determined in 257 diabetic patients (117 patients with type 1 and 140 with type 2 diabetes). The control group consisted of 221 age- and gender-matched healthy blood donors. The cumulative copy numbers of the DEFA1/DEFA3 genes were detected by using quantitative PCR analysis. To evaluate the HNP 1-3 (human neutrophil peptide 1-3 or α-defensin) levels in the circulation, plasma HNP 1-3 concentrations were measured by ELISA. The expression of DEFA1/A3 in peripheral leukocytes of the diabetic patients was measured by quantitative RT PCR analysis. Three SNPs of the human DEFB1 (human defensin β-1) gene: DEFB1 G-20A (rs11362), DEFB1 C-44G (rs1800972) and DEFB1 G-52A (rs1799946) were genotyped by Custom TaqMan^® Real Time PCR assay.

RESULTS: Significant differences were observed in HNP1-3 levels between the healthy subjects and both groups of diabetic patients. The mean ± SE was 28.78 ± 4.2 ng/mL in type 1 diabetes, and 29.82 ± 5.36 ng/mL in type 2 diabetes, vs 11.94 ± 2.96 ng/mL in controls; P < 0.01 respectively. There was no significant difference between patients with type 1 and type 2 diabetes in the high plasma concentrations of HNP1-3. The highest concentrations of α-defensin were found in diabetic patients with nephropathy (49.4 ± 4.8 ng/mL), neuropathy (38.7 ± 4.8 ng/mL) or cardiovascular complications (45.6 ± 1.45 ng/L). There was no significant difference in the cumulative copy numbers of DEFA1/DEFA3 genes between controls and patients, or between patients with the two types of diabetes. Comparisons of HNP 1-3 plasma level and DEFA1/A3 copy number of the same patient did not reveal significant relationship between defensin-α levels and the gene copy numbers (r² = 0.01). Similarly, no positive correlation was observed between the copy numbers and the mRNA expression levels of DEFA1/A3. Regarding the C-44G polymorphism of DEFB1, the GG “protective” genotype was much less frequent (1%-2%) among both groups of patients than among controls (9%).

CONCLUSION: Elevated HNP1-3 levels in diabetes are independent of DEFA1/DEFA3 copy numbers, but GG genotype of C-44G SNP in DEFB1 gene may result in decreased defensin β-1 production.

Mesenchymal stem cell therapy for cardiac inflammation: immunomodulatory properties and the influence of toll-like receptors

BACKGROUND

After myocardial infarction (MI), the inflammatory response is indispensable for initiating reparatory processes. However, the intensity and duration of the inflammation cause additional damage to the already injured myocardium. Treatment with mesenchymal stem cells (MSC) upon MI positively affects cardiac function. This happens likely via a paracrine mechanism. As MSC are potent modulators of the immune system, this could influence this postinfarct immune response. Since MSC express toll-like receptors (TLR), danger signal (DAMP) produced after MI could influence their immunomodulatory properties.

SCOPE OF REVIEW

Not much is known about the direct immunomodulatory efficiency of MSC when injected in a strong inflammatory environment. This review focuses first on the interactions between MSC and the immune system. Subsequently, an overview is provided of the effects of DAMP-associated TLR activation on MSC and their immunomodulative properties after myocardial infarction.

MAJOR CONCLUSIONS

MSC can strongly influence most cell types of the immune system. TLR signaling can increase and decrease this immunomodulatory potential, depending on the available ligands. Although reports are inconsistent, TLR3 activation may boost immunomodulation by MSC, while TLR4 activation suppresses it.

GENERAL SIGNIFICANCE

Elucidating the effects of TLR activation on MSC could identify new preconditioning strategies which might improve their immunomodulative properties.

Transgenic expression of human neutrophil peptide-1 enhances hepatic fibrosis in mice fed a choline-deficient, L-amino acid-defined diet

BACKGROUND

Neutrophils infiltrate the livers of patients with nonalcoholic steatohepatitis (NASH). Human neutrophil peptides (HNPs) induce cytokine and chemokine production under inflammatory conditions, which may contribute to the progression of NASH. In this study, we focused on the effects of HNP-1 on hepatic steatosis and fibrosis in a mouse model of NASH induced by a choline-deficient, L-amino acid-defined (CDAA) diet.

MATERIALS & METHODS

We generated transgenic mice expressing HNP-1 under the control of a β-actin-based promoter. HNP-1 transgenic and wild-type C57BL/6N mice were fed a CDAA diet for 16 weeks to induce hepatic steatosis and fibrosis. Serological and histological features were examined, and the effects of HNP-1 on hepatic stellate cell lines were assessed.

RESULTS

HNP-1 transgenic and wild-type mice fed the CDAA diet showed no significant differences in serum alanine aminotransferase levels or the degree of hepatic steatosis based on Oil red O staining and hepatic triglyceride content. In contrast, Sirius Red and Azan staining showed significantly more severe hepatic fibrosis in HNP-1 transgenic mice compared with wild-type mice. In addition, significantly more α-smooth muscle actin-positive hepatic stellate cells were observed in the transgenic mice than in the wild-type mice. Finally, the proliferation of the LI90 hepatic stellate cell line increased in response to HNP-1.

CONCLUSION

Our data indicate that HNP-1 enhances hepatic fibrosis in fatty liver by inducing hepatic stellate cell proliferation. Thus, neutrophil-derived HNP-1 may contribute to the progression of NASH.

Chemokines and Their Receptors Are Key Players in the Orchestra That Regulates Wound Healing

SIGNIFICANCE

Normal wound healing progresses through a series of overlapping phases, all of which are coordinated and regulated by a variety of molecules, including chemokines. Because these regulatory molecules play roles during the various stages of healing, alterations in their presence or function can lead to dysregulation of the wound-healing process, potentially leading to the development of chronic, nonhealing wounds.

RECENT ADVANCES

A discovery that chemokines participate in a variety of disease conditions has propelled the study of these proteins to a level that potentially could lead to new avenues to treat disease. Their small size, exposed termini, and the fact that their only modifications are two disulfide bonds make them excellent targets for manipulation. In addition, because they bind to G-protein-coupled receptors (GPCRs), they are highly amenable to pharmacological modulation.

CRITICAL ISSUES

Chemokines are multifunctional, and in many situations, their functions are highly dependent on the microenvironment. Moreover, each specific chemokine can bind to several GPCRs to stimulate the function, and both can function as monomers, homodimers, heterodimers, and even oligomers. Activation of one receptor by any single chemokine can lead to desensitization of other chemokine receptors, or even other GPCRs in the same cell, with implications for how these proteins or their receptors could be used to manipulate function.

FUTURE DIRECTIONS

Investment in better understanding of the functions of chemokines and their receptors in a local context can reveal new ways for therapeutic intervention. Understanding how different chemokines can activate the same receptor and vice versa could identify new possibilities for drug development based on their heterotypic interactions.

Characterization of Antimicrobial Peptides toward the Development of Novel Antibiotics

Antimicrobial agents have eradicated many infectious diseases and significantly improved our living environment. However, abuse of antimicrobial agents has accelerated the emergence of multidrug-resistant microorganisms, and there is an urgent need for novel antibiotics. Antimicrobial peptides (AMPs) have attracted attention as a novel class of antimicrobial agents because AMPs efficiently kill a wide range of species, including bacteria, fungi, and viruses, via a novel mechanism of action. In addition, they are effective against pathogens that are resistant to almost all conventional antibiotics. AMPs have promising properties; they directly disrupt the functions of cellular membranes and nucleic acids, and the rate of appearance of AMP-resistant strains is very low. However, as pharmaceuticals, AMPs exhibit unfavorable properties, such as instability, hemolytic activity, high cost of production, salt sensitivity, and a broad spectrum of activity. Therefore, it is vital to improve these properties to develop novel AMP treatments. Here, we have reviewed the basic biochemical properties of AMPs and the recent strategies used to modulate these properties of AMPs to enhance their safety.

ACTH- and cortisol-associated neutrophil modulation in coronary artery disease patients undergoing stent implantation

Background

Psychosocial stress and activation of neutrophil granulocytes are increasingly recognized as major risk factors of coronary artery disease (CAD), but the possible relationship of these two factors in CAD patients is largely unexplored. Activation of neutrophils was reported to be associated with stenting; however, the issue of neutrophil state in connection with percutaneous coronary intervention (PCI) is incompletely understood from the aspect of stress and its hypothalamic-pituitary-adrenal axis (HPA) background. Thus, we aimed to study cortisol- and ACTH-associated changes in granulocyte activation in patients undergoing PCI.

Methodology/Principal Findings

Blood samples of 21 stable angina pectoris (SAP) and 20 acute coronary syndrome (ACS) patients were collected directly before (pre-PCI), after (post-PCI) and on the following day of PCI (1d-PCI). Granulocyte surface L-selectin, CD15 and (neutrophil-specific) lactoferrin were analysed by flow cytometry. Plasma cortisol, ACTH, and lactoferrin, IL-6 were also assayed. In both groups, pre- and post-PCI ratios of lactoferrin-bearing neutrophils were relatively high, these percentages decreased substantially next day; similarly, 1d-PCI plasma lactoferrin was about half of the post-PCI value (all p≤0.0001). Post-PCI ACTH was reduced markedly next day, especially in ACS group (SAP: p<0.01, ACS: p≤0.0001). In ACS, elevated pre-PCI cortisol decreased considerably a day after stenting (p<0.01); in pre-PCI samples, cortisol correlated with plasma lactoferrin (r∼0.5, p<0.05). In 1d-PCI samples of both groups, ACTH showed negative associations with the ratio of lactoferrin-bearing neutrophils (SAP: r = −0.601, p<0.005; ACS: r = −0.541, p<0.05) and with plasma lactoferrin (SAP: r = −0.435, p<0.05; ACS: r = −0.609, p<0.005).

Conclusions/Significance

Pre- and post-PCI states were associated with increased percentage of activated/degranulated neutrophils indicated by elevated lactoferrin parameters, the 1d-PCI declines of which were associated with plasma ACTH in both groups. The correlation of plasma cortisol with plasma lactoferrin in the extremely stressed ACS before stenting, however, suggests an association of cortisol with neutrophil activation.

Monitoring states of altered carbohydrate metabolism via breath analysis: are times ripe for transition from potential to reality?

PURPOSE OF REVIEW

To introduce the potential of breath analysis as a diagnostic or monitoring tool in diabetes.

RECENT FINDINGS

Blood testing for plasma glucose and other metabolic variables is the base for the diagnosis and management of diabetes, whose two main types (type 1 and type 2, T1DM, T2DM) are projected to affect 450 million by 2030. As blood testing is often uncomfortable, painful, costly, and in some situations unreliable, the quest for alternative, noninvasive methods has been ongoing for decades. Breath analysis has emerged as an ideal alternative as sample collection is easy, painless, flexible, noninvasive, practical, and inexpensive. No single exhaled gas can reflect systemic glucose concentrations. Multiple gases, however, have been linked to various aspects of glucose metabolism, and integrated analysis of their simultaneous profiles during prolonged glycemic fluctuations has yielded accurate predictions of plasma values, building expectation that a clinically usable breath-based glucometer may be developed within a few years.

SUMMARY

While prototypes of hand-held breath testing glucometers may still be several years away, current research shows the imminent promise of this methodology and the widening support for its development.

Leukocyte and leukocyte subset counts reveal compensatory mechanisms in coronary heart disease

BACKGROUND

Leukocyte number in the circulation plays a central role in inflammatory diseases, such as coronary heart disease (CHD). Increased counts are correlated with the intensity of the peri-infarction inflammatory response and adverse outcomes. We investigated leukocyte and leukocyte subset counts in dyslipidaemia patients and their relationship with LDL oxidation.

METHODS

Dyslipidaemia patients (207) were selected for blood counts and LDL-C testing. The level of HNP-1and myeloperoxidase in subsets of leukocytes and their relationship with LDL oxidation were compared between 24 CHD patients and 24 normal controls.

RESULTS

In dyslipidaemia patients, total leukocyte and neutrophil counts increased with LDL-C (p=0.001). Monocyte counts showed the opposite trend (p=0.001). Although serum HNP-1 levels were not different between CHD patients and normal controls (p=0.558), neutrophil HNP-1 mRNA levels were 2.13-fold greater than those of normal controls. However, monocyte HNP-1 mRNA levels were lower (p=0.005). The distribution of myeloperoxidase in monocytes and neutrophils is different, myeloperoxidase locates mainly in the cytoplasm of monocytes, on the cell membrane of neutrophils.

CONCLUSIONS

Leukocyte and leukocyte subset counts may correlate with LDL-C levels and LDL oxidation. The monocyte-neutrophil interaction reveals a potential compensatory mechanism associated with LDL oxidation in CHD that may be a prognostic factor of CHD.

Cardiac stem cell therapy to modulate inflammation upon myocardial infarction

BACKGROUND

After myocardial infarction (MI) a local inflammatory reaction clears the damaged myocardium from dead cells and matrix debris at the onset of scar formation. The intensity and duration of this inflammatory reaction are intimately linked to post-infarct remodeling and cardiac dysfunction. Strikingly, treatment with standard anti-inflammatory drugs worsens clinical outcome, suggesting a dual role of inflammation in the cardiac response to injury. Cardiac stem cell therapy with different stem or progenitor cells, e.g. mesenchymal stem cells (MSC), was recently found to have beneficial effects, mostly related to paracrine actions. One of the suggested paracrine effects of cell therapy is modulation of the immune system.

SCOPE OF REVIEW

MSC are reported to interact with several cells of the immune system and could therefore be an excellent means to reduce detrimental inflammatory reactions and promote the switch to the healing phase upon cardiac injury. This review focuses on the potential use of MSC therapy for post-MI inflammation. To understand the effects MSC might have on the post-MI heart the cellular and molecular changes in the myocardium after MI need to be understood.

MAJOR CONCLUSIONS

By studying the general pathways involved in immunomodulation, and examining the interactions with cell types important for post-MI inflammation, it becomes clear that MSC treatment might provide a new therapeutic opportunity to improve cardiac outcome after acute injury.

GENERAL SIGNIFICANCE

Using stem cells to target the post-MI inflammation is a novel therapy which could have considerable clinical implications. This article is part of a Special Issue entitled Biochemistry of Stem Cells.

The clinical potential of exhaled breath analysis for diabetes mellitus

Various compounds in present human breath have long been loosely associated with pathological states (including acetone smell in uncontrolled diabetes). Only recently, however, the precise measurement of exhaled volatile organic compounds (VOCs) and aerosolized particles was made possible at extremely low concentrations by advances in several analytical methodologies, described in detail in the international literature and each suitable for specific subsets of exhaled compounds. Exhaled gases may be generated endogenously (in the pulmonary tract, blood, or peripheral tissues), as metabolic by-products of human cells or colonizing micro-organisms, or may be inhaled as atmospheric pollutants; growing evidence indicates that several of these molecules have distinct cell-to-cell signaling functions. Independent of origin and physiological role, exhaled VOCs are attractive candidates as biomarkers of cellular activity/metabolism, and could be incorporated in future non-invasive clinical testing devices. Indeed, several recent studies reported altered exhaled gas profiles in dysmetabolic conditions and relatively accurate predictions of glucose concentrations, at least in controlled experimental conditions, for healthy and diabetic subjects over a broad range of glycemic values. Optimization of this methodology and validation in large-scale trials under a wider range of conditions is needed to determine its true potential to transition into practical clinical use.