Elastase Research Articles

Approaches to Control and Monitor Protease Levels in Chronic Wounds

AbstractSome wounds do not follow the typical healing trajectory and show very little, if any, progress. They dreadfully threaten the patients' quality of life and may even lead to limb amputation and death. Several interrelated systemic and local factors may cause a delay in wound healing. The microenvironment of these wounds can be different from wounds that heal spontaneously or with standard treatment. As discussed in the present work, proteases’ levels or activity can be elevated in some cases of chronic ulcers; infection can aggravate the situation. A detailed overview of the proteases’ effect on wound healing is presented in this work. Assuming untimely or irregularly excessive proteolytic activity plays a pathological role, some researchers targeted attenuation of protease level as a strategy to promote healing. This can be done via different approaches, including physical removal, inhibiting their activity, and controlling their expression directly through gene silencing or indirectly, for instance, by resolving infection. Apart from targeting protease modulation as a therapeutic strategy, many studies have examined the protease state to gain insights into the underlying mechanisms by which a remedy, dressing, or specific therapy has affected the healing process. This study aims to provide an overview of the studies in these two categories. Of course, various proteases are involved in the healing process, but in each study, usually, only one or some of them are investigated; matrix metalloproteinase‐2 (MMP‐2), MMP‐9, and human neutrophil elastase (HNE) are among them. Furthermore, in some cases, cumulative proteolytic activity is evaluated in terms of gelatinolytic, collagenolytic, or caseinolytic activity, which is also absolutely beneficial. Some research groups have considered the potential of proteases as a diagnostic or prognostic biomarker and have tried to develop some sensors or indicators; this topic is also covered in the present work.

Resveratrol prevents the release of neutrophil extracellular traps (NETs) by controlling hydrogen peroxide levels and nuclear elastase migration.

Neutrophil extracellular traps (NETs) are defense mechanisms that trap and kill microorganisms and degrade cytokines. However, excessive production, dysregulation of suppression mechanisms, or inefficient removal of NETs can contribute to increased inflammatory response and the development of pathological conditions. Therefore, research has focused on identifying drugs that inhibit or delay the NET release process. Since reactive oxygen species (ROS) play a significant role in NET release, we aimed to investigate whether resveratrol (RSV), with a wide range of biological and pharmacological properties, could modulate NET release in response to different stimuli. Thus, human neutrophils were pretreated with RSV and subsequently stimulated with PMA, LPS, IL-8, or Leishmania. Our findings revealed that RSV reduced the release of NETs in response to all tested stimuli. RSV decreased hydrogen peroxide levels in PMA- and LPS-stimulated neutrophils, inhibited myeloperoxidase activity, and altered the localization of neutrophil elastase. RSV inhibition of NET generation was not mediated through A2A or A2B adenosine receptors or PKA. Based on the observed effectiveness of RSV in inhibiting NET release, our study suggests that this flavonoid holds potential as a candidate for treating NETs involving pathologies.

Corilagin Inhibits Neutrophil Extracellular Trap Formation and Protects against Hydrochloric Acid/Lipopolysaccharide-Induced Acute Lung Injury in Mice by Suppressing the STAT3 and NOX2 Signaling Pathways.

Acute lung injury (ALI) and its severe manifestation, acute respiratory distress syndrome (ARDS), are characterized by uncontrolled inflammatory responses, neutrophil activation and infiltration, damage to the alveolar capillary membrane, and diffuse alveolar injury. Neutrophil extracellular traps (NETs), formed by activated neutrophils, contribute significantly to various inflammatory disorders and can lead to tissue damage and organ dysfunction. Corilagin, a compound found in Phyllanthus urinaria, possesses antioxidative and anti-inflammatory properties. In this study, we investigated the protective effects and underlying mechanisms of corilagin in hydrochloric acid (HCl)/lipopolysaccharide (LPS)-induced lung injury. Mice received intraperitoneal administration of corilagin (2.5, 5, or 10 mg/kg) or an equal volume of saline 30 min after intratracheal HCl/LPS administration. After 20 h, lung tissues were collected for analysis. Corilagin treatment significantly mitigated lung injury, as evidenced by reduced inflammatory cell infiltration, decreased production of proinflammatory cytokines, and alleviated oxidative stress. Furthermore, corilagin treatment suppressed neutrophil elastase expression, reduced NET formation, and inhibited the expression of ERK, p38, AKT, STAT3, and NOX2. Our findings suggest that corilagin inhibits NET formation and protects against HCl/LPS-induced ALI in mice by modulating the STAT3 and NOX2 signaling pathways.

Advancing Nonsmall Cell Lung Cancer Diagnosis Accuracy via Dual Detection Fluorescent Nanoprobes.

Among the primary threats to human health worldwide, nonsmall cell lung cancer (NSCLC) remains a significant factor and is a leading cause of cancer-related deaths. Due to subtle early symptoms, NSCLC patients are diagnosed at advanced stages, resulting in low survival rates. Herein, novel Au-Se bond nanoprobes (NPs) designed for the specific detection of Calpain-2 (CAPN2) and Human Neutrophil Elastase (HNE), pivotal biomarkers in NSCLC, were developed. The NPs demonstrated exceptional specificity and sensitivity toward CAPN2 and HNE, enabling dual-color fluorescence imaging to distinguish between NSCLC cells and normal lung cells effectively. The NPs' performance was consistent across a wide pH range (6.2 to 8.0), and it exhibited remarkable resistance to biological thiol interference, indicating its robustness in complex physiological environments. These findings suggest the nanoprobe is a promising tool for early NSCLC diagnosis, offering a novel approach for enhancing the accuracy of cancer detection.

Extracellular traps development in canine neutrophils induced by infective stage Toxocara canis larvae

Neutrophils, a crucial element of the host defense system, develop extracellular traps against helminth parasites. Neutrophils accumulate around the larvae of Toxocara canis (T. canis) in the tissues of the organism. This study aimed to determine the reaction in canine neutrophils after incubation with infective stage T. canis larvae (L3) in vitro. Most L3 were still active and moved between the extracellular traps (NETs) after 60-min incubation. NETs were not disintegrated by L3 movement. The L3 was only immobilized by NETs, entrapped larvae were still motile between the traps at the 24 h incubation. NETs were observed not only to accumulate around the mouth, excretory pole or anus but also the entire body of live L3. The extracellular DNA amount released from the canine neutrophils after being induced with phorbol 12-myristate 13-acetate was not affected by T. canis excretory/secretory products obtained from 250 L3. To the Authors’knowledge, the extracellular trap structures was firstly observed in canine neutrophils against T. canis L3 in vitro. NETs decorated with myeloperoxidase, neutrophil elastase and histone (H3) were observed under fluorescence microscope. There were not significant differences in the amount of extracellular DNA (P > 0.05), but the morphological structure of NETs was different in the live and head-inactivated T. canis larvae.

Neutrophil Elastase Degrades Histone Deacetylases and Sirtuin 1 in Primary Human Monocyte Derived Macrophages.

Neutrophil elastase (NE) is taken up by macrophages, retains intracellular protease activity, and induces a pro-inflammatory phenotype. However, the mechanism of NE-induced pro-inflammatory polarization of macrophages is not well understood. We hypothesized that intracellular NE degrades histone deacetylases (HDAC) and Sirtuins, disrupting the balance of lysine acetylation and deacetylation and resulting in nuclear to cytoplasmic translocation of a major alarmin, High Mobility Group Box 1 (HMGB1), a pro-inflammatory response in macrophages. Human blood monocytes were obtained from healthy donors or from subjects with cystic fibrosis (CF) or chronic obstructive pulmonary disease (COPD). Monocytes were differentiated into blood monocyte derived macrophages (BMDMs) in vitro. Human BMDMs were exposed to NE or control vehicle, and the abundance of HDACs and Sirtuins was determined by Western blotting of total cell lysates or nuclear extracts or determined by ELISA. HDAC, Sirtuin, and Histone acetyltransferase (HAT) activities were measured. NE degraded most HDACs and Sirtuin (Sirt)1, resulting in decreased HDAC and sirtuin activities, with minimal change in HAT activity. We then evaluated whether the NE-induced loss of Sirt activity or loss of HDAC activities would alter the cellular localization of HMGB1. NE treatment or treatment with Trichostatin A (TSA), a global HDAC inhibitor, both increased HMGB1 translocation from the nucleus to the cytoplasm, consistent with HMGB1 activation. NE significantly degraded Class I and II HDAC family members and Sirt 1, which shifted BMDMs to a pro-inflammatory phenotype.

Endothelial PTP1B Deletion Promotes VWF Exocytosis and Venous Thromboinflammation.

Endothelial activation promotes the release of procoagulant extracellular vesicles and inflammatory mediators from specialized storage granules. Endothelial membrane exocytosis is controlled by phosphorylation. We hypothesized that the absence of PTP1B (protein tyrosine phosphatase 1B) in endothelial cells promotes venous thromboinflammation by triggering endothelial membrane fusion and exocytosis. Mice with inducible endothelial deletion of PTP1B (End.PTP1B-KO) underwent inferior vena cava ligation to induce stenosis and venous thrombosis. Primary endothelial cells from transgenic mice and human umbilical vein endothelial cells were used for mechanistic studies. Vascular ultrasound and histology showed significantly larger venous thrombi containing higher numbers of Ly6G (lymphocyte antigen 6 family member G)-positive neutrophils in mice with endothelial PTP1B deletion, and intravital microscopy confirmed the more pronounced neutrophil recruitment following inferior vena cava ligation. RT2 PCR profiler array and immunocytochemistry analysis revealed increased endothelial activation and adhesion molecule expression in primary End.PTP1B-KO endothelial cells, including CD62P (P-selectin) and VWF (von Willebrand factor). Pretreatment with the NF-κB (nuclear factor kappa B) kinase inhibitor BAY11-7082, antibodies neutralizing CD162 (P-selectin glycoprotein ligand-1) or VWF, or arginylglycylaspartic acid integrin-blocking peptides abolished the neutrophil adhesion to End.PTP1B-KO endothelial cells in vitro. Circulating levels of annexin V+ procoagulant endothelial CD62E+ (E-selectin) and neutrophil (Ly6G+) extracellular vesicles were also elevated in End.PTP1B-KO mice after inferior vena cava ligation. Higher plasma MPO (myeloperoxidase) and Cit-H3 (citrullinated histone-3) levels and neutrophil elastase activity indicated neutrophil activation and extracellular trap formation. Infusion of End.PTP1B-KO extracellular vesicles into C57BL/6J wild-type mice most prominently enhanced the recruitment of endogenous neutrophils, and this response was blunted in VWF-deficient mice or by VWF-blocking antibodies. Reduced PTP1B binding and tyrosine dephosphorylation of SNAP23 (synaptosome-associated protein 23) resulting in increased VWF exocytosis and neutrophil adhesion were identified as mechanisms, all of which could be restored by NF-κB kinase inhibition using BAY11-7082. Our findings show that endothelial PTP1B deletion promotes venous thromboinflammation by enhancing SNAP23 phosphorylation, endothelial VWF exocytosis, and neutrophil recruitment.

Logistic regression model for the prediction of asthenia development in schizophrenia based on inflammatory blood markers

IntroductionAccording to a number of authors, inflammation is involved in the development of asthenic syndrome in different diseases. The results of our own studies indicate that the main feature of the spectrum of inflammatory markers in patients with asthenic syndrome in schizophrenia is low enzymatic activity of leukocyte elastase against the background of high levels of other inflammatory markers. Presumably, the decrease in LE activity may be associated with functional exhaustion of neutrophils and/or their transmigration to the brain through the disrupted blood-brain barrier due to a long-term chronic inflammatory process.ObjectivesTo create a logistic regression model for predicting the development of asthenia in schizophrenia based on the analysis of the association between leukocyte elastase (LE) and α1-proteinase inhibitor (α1-PI) activity in blood plasma.MethodsA database including clinical and demographic parameters (ICD-10 diagnosis, duration of the disease, psychometric evaluation according to the PANSS and MFI-20 scales, sex and age) and immunological parameters (enzymatic activity of LE and functional activity of α1-PI in blood plasma) of 95 patients from 22 to 55 years old with paroxysmal-progressive (F20.x1) and paranoid (F20.00) schizophrenia was used to construct the model. An asthenic symptom complex was diagnosed in 61 patients.ResultsA binary logistic regression model linking the probability of developing asthenia to LE and α1-PI activity was constructed by analyzing a database of patients with schizophrenia.P=1/(1+exp [-(11.71-0.057-LE+0.027-α1-PI)] (2), whereP is the probability of asthenia development; exp is the base of the natural logarithm; 11.71 is the regression constant; 0.057 is the coefficient for LE; 0.027 is the coefficient for α1-PI.This model adequately describes the clinical data and has good predictive ability (sensitivity - 93.44%, specificity - 76.47%, AUC - 0.89).ConclusionsA binary logistic regression model was created to predict the development of asthenia in schizophrenia using immunological parameters LE and α1-PI. The model is highly effective and can complement clinical examination of patients with schizophrenia, contributing to the objective diagnosis of asthenic syndrome and, consequently, timely therapeutic correction.Disclosure of InterestNone Declared

Subgroups of patients with late onset schizophrenia-like psychoses revealed by the analysis of glutathione-dependent enzymes and inflammation markers

IntroductionWhile chronic inflammation and enhanced imbalance of pro- and antioxidant, including glutathione-dependent, systems contribute substantially to pathogenesis of mental disorders in old age, extent of oxidative stress and degree of inflammatory processes severity are varying among patients with late onset schizophrenia.ObjectivesRevealing various phenotypes in patients with late onset schizophrenia basing on measurement of activity levels for blood glutathione-dependent enzymes and inflammation markers and analysis of their links with clinical features of the patients.MethodsOf 59 studied women patients 34 were with late onset (after 40 years) and 25 with very late onset (after 60 years) schizophrenia or schizophrenia-like psychoses (F20; F22.8; F25; F23; F06.2 by ICD-10). 34 mentally healthy women elder than 50 years comprised controls. Glutathione reductase (GR), glutathione-S-transferase (GST), neutrophil elastase (NE), and α1-roteinase inhibitor (α1-PI) activities were measured in blood. PANSS, CDSS and CGI-S were used to assess the severity of psychotic symptoms, depression and treatment effectiveness.ResultsIn the whole group of patients, GR was lower (p<0.05), and α1-PI was higher (p<0.0001) than in control group. Clustering the patients by their biochemical and immunological signs revealed two clusters (C1, n=34, and C2, n=25) significantly differing by GST (p<0.0001), NE (p<0.0001), and α1-PI (p<0.001) activities. As compared with controls, GST and α1-PI were higher (p<0.05 and p<0.0001), and NE was lower (p<0.05) in C1. As compared with controls, GR activity was lower (p<0.05), NE activity was higher (p<0.001), and α1-PI activity was much higher (p<0.001) in C2. Patients of C1 and C2 did not differ in age, diagnosis, severity of the disease, but differed in clinical features of the course of the disease: significantly more patients with very late onset schizophrenia (76%) were met in C1 (χ2=13.41, p<0.001). Also, different clinical-biological correlations were found in these clusters. Particularly, negative correlations of baseline NE activity with PANSS general psychopathology subscale scores (R=-0.39, p<0.05) and with total PANSS scores (R=-0.39, p<0.05) were found in C1. Positive correlation of GST activity with PANSS positive subscale score was found in C2 (R=0.43, p<0.05).ConclusionsThe revealed clusters differ in the extent of the glutathione antioxidant system impairment and in levels of the immune response markers. The revealing of the patient subgroups on the basis of biological markers reflecting impairments in metabolic and immune systems can represent interest in the search for individual treatment approaches.Disclosure of InterestNone Declared

Features of the spectrum of immune markers in patients with juvenile depression with clinically high risk of psychosis

IntroductionIdentification of biomarkers associated with the risk of psychosis manifestation in juvenile patients with depression may contribute to a better understanding of the pathogenesis of mental disorders and early diagnosis.ObjectivesTo determine the level of pro-inflammatory and anti-inflammatory cytokines and other inflammatory indicators in the plasma of juvenile patients with depression and clinically high risk of psychosis, and to study the correlation of these markers with the severity of psychopathologic symptoms.Methods80 young men aged 16-24 years with the first depressive episode (F32.1-2, F32.38, F32.8) were examined. Based on the severity of attenuated psychotic symptoms (APS) in the structure of depression according to the SOPS scale, all patients were divided into two groups - with clinically high risk of psychosis (n=58) and with depression without APS (n=22). The HDRS-21 and SANS scales were also used for psychometric assessment. Serum level of cytokines TNF-α, IL-6, IL-8, IL-10, TNF-α/IL-6 ratio, TNF-α/IL-10 ratio, leukocyte elastase (LE) and α1-proteinase inhibitor (α1-PI) activity, C-reactive protein (CRP) concentration, and the level of autoantibodies to S-100B protein were determined.ResultsBoth groups of patients showed a high level of inflammation assessed by LE and α1-PI activity (p>0.05). Significantly higher level of IL-6 (p=0.03), CRP concentration (p=0.026) and TNF-α/IL-10 ratio (p=0.032) were found in patients with clinically high risk of psychosis. This group was also characterised by high level of autoantibodies to the S-100B protein compared to patients with depression without APS (p=0.048). In the high clinical risk group, correlations were found between the SOPS positive subscale score and the level of TNF-α (R=0.32, p=0.017), IL-8 (R=-0.3, p=0.034), TNF-α/IL-6 ratio (R=0.30, p=0.021) and TNF-α/IL-10 ratio (R=0.32, p=0.014). The SOPS negative subscale score correlated with CRP concentration (R=0.3, p=0.043). The SOPS total score correlated with TNF-α/IL-10 ratio (R=0.31, p=0.021). In this group of patients, the level of IL-10 was found to correlate with the duration of the disease (R=0.48, p<0.001). In patients with depression without APS, the level of IL-6 was correlated with the severity of depression according to the HDRS scale, and the level of TNF-α was associated with the duration of the depressive episode (R=0.51, p=0.029).ConclusionsThe obtained results confirm the involvement of inflammation in the development of juvenile depression. Qualitative and quantitative characteristics of the spectrum of immune markers and the cytokine profile, and correlations with the severity of psychopathologic symptoms were revealed in patients with clinically high risk of psychosis.Disclosure of InterestNone Declared

A neutrophil elastase inhibitor, sivelestat, attenuates sepsis-induced acute kidney injury by inhibiting oxidative stress

BackgroundSivelestat, a selective inhibitor of neutrophil elastase (NE), can mitigate sepsis-related acute lung injury. However, the role of sivelestat in inhibiting oxidative stress and attenuating sepsis-related acute kidney injury (AKI) remains unclear. Here, we reported the effects of sivelestat against oxidative stress-induced AKI by suppressing the production of oxidative stress indicators. Materials and methodsA male Sprague-Dawley rat model of sepsis was established by cecal ligation and puncture (CLP). Sivelestat or normal saline was administered into jugular vein with a sustained-release drug delivery system. Indicators of inflammation and AKI, including white blood cells (WBC), neutrophils, lymphocytes, C-reactive proteins (CRP), procalcitonin (PCT), blood urea nitrogen (BUN), creatinine (Cr) and uric acid (UA), were assessed at 24 h post-sivelestat treatment. Indicators of liver injury, including direct bilirubin (DBIL), indirect bilirubin (IBIL), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), were also assessed at 24 h post-sivelestat treatment. Indicators of oxidative stress, including superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px), were assessed at 12 h and 24 h post-sivelestat treatment. At 24 h post-sivelestat treatment, H&E staining of kidney and liver tissue was performed to observe pathological alterations. ResultsAt 24 h post normal saline or sivelestat (0.2 g/kg body weight) treatment, WBC, neutrophil, CRP, PCT, MDA, BUN, Cr, UA, AST, ALT, DBIL and IBIL were increased, while SOD and GSH-Px were decreased, in septic rats treated with normal saline compared with that in non-septic rats treated with normal saline (all p < 0.05). The changes of these indicators were reversed in septic rats treated with sivelestat compared with that in septic rats treated with normal saline (all p < 0.05). Similar results were found regarding the levels of oxidative stress indicators at 12 h post-sivelestat treatment. The degenerative histopathological changes in both kidney and liver tissues were ameliorated upon sivelestat treatment. ConclusionsSivelestat plays a protective role in sepsis-related AKI by inhibiting oxidative stress. Our study reveals a possible therapeutic potential of sivelestat for oxidative stress-induced AKI.

Immunological predictors of rhythmic transcranial magnetic stimulation (rTMS) efficiency in patients with treatment-resistant schizophrenia

IntroductionModel and clinical studies demonstrate the efficiency of rhythmic transcranial magnetic stimulation (rTMS) in diseases associated with neuroinflammation. The therapeutic potential of rTMS is related to modulation of neuroplasticity in the CNS, activation of neurogenesis and reduction of neuroinflammatory processes. Presumably, one of the factors that determines the efficiency of rTMS can be the features of the immune status of patients.ObjectivesTo reveal the features of the spectrum of inflammatory markers in patients with treatment-resistant schizophrenia with different efficiency of rTMS.Methods 31 male patients aged 16 to 47 years (mean age 29.9 ± 8.4 years) with treatment-resistant schizophrenia who developed a first psychotic episode in adolescence (19-25 years) were examined. The course of rTMS was conducted for 3 weeks (15 sessions). Depending on the dynamics of clinical and psychometric parameters after the course of rTMS, the patients were divided into three groups: group 1 - with worsening of clinical condition (n=8); group 2 - without therapeutic effect (n=12); group 3 - with good therapeutic response (n=11). Before rTMS, leukocyte elastase (LE) and α1-proteinase inhibitor (α1-PI) activity, and the levels of autoantibodies to S-100B protein and myelin basic protein (MBP) in the plasma of patients were determined. The parameters of 18 healthy male donors without clinical signs of psychiatric and somatic pathology were used as controls.ResultsAll groups of patients were characterised by moderate and high levels of immune system activation, determined by a complex of inflammatory and autoimmune markers. At the same time, the high level of immune system activation in patients with low MTR efficiency was associated with low LE activity in plasma (within the reference range or below the lower limit - 200.6 (168.5- 220.3) nmol/min·mL), which was not consistent with the overall level of inflammation. This group of patients also showed high levels of antibodies to MBP compared to control values (p&lt;0.05). The low LE activity can be explained by the transmigration of neutrophils from the blood to the brain due to a critical increase in the permeability of the blood-brain barrier, which is largely controlled by LE.ConclusionsThe study confirmed the participation of immune mechanisms in the formation of therapeutic resistance in schizophrenia and revealed the characteristics of the spectrum of immune markers in patients with low efficiency of rTMS.Disclosure of InterestNone Declared

Connection of molecular and cellular components of the immune system in endogenous psychoses with depressive-delusional symptoms

IntroductionThe data of current research indicate the participation of systemic inflammation in the pathogenesis of endogenous psychoses. Changes in the level of peripheral immune markers are associated with the development of neuroinflammation and correlate with the severity of psychopathological symptoms detected in patients. However, the association between individual components of the immune system involved in the development of endogenous psychosis remains poorly understood.ObjectivesTo study the connection between molecular and cellular components of the immune system in women with endogenous psychoses with depressive-delusional symptoms.Methods32 female patients aged 23 [17; 36] years with endogenous psychoses within different nosologies (F20, F21, F31, depressive-delusional conditions) and 17 women without clinical signs of psychiatric pathology were examined. The activity of leukocyte elastase (LE), α1-proteinase inhibitor (α1-PI), the proportion of four subpopulations of monocytes (classical CD14++CD16-, intermediate CD14++CD16+, nonclassical CD14+CD16+ and transitional CD14+CD16-) in plasma, activity of cytochrome-c oxidase (COX), glutamate dehydrogenase (GDH), glutathione s-transferase (GST) and glutathione reductase (GR) in platelets and functional activity of complement system (faCS) in serum were determined. The PANSS scale was used to assess the severity of psychopathological symptoms.ResultsIncreased activity of the inflammatory markers LE (p=0.033) and α1-PI (p=0.02) was found in the plasma of the patients. Increased percentage of pro-inflammatory monocytes (intermediate and transient) in plasma (p=0.003) was confirmed by negative correlations between CD14++CD16- and CD14++CD16+ (R=-0.685, p=0.00002), CD14++CD16- and CD14+CD16- (R=-0.608, p=0.0002), CD14++CD16- and CD14+CD16+ (R=-0.424, p=0.002). A decrease in GDH activity (p=0.0079), GST activity (p=0.002) and GR activity (p=0.0006) was observed in patient platelets, which can reflect changes in the activity of intracellular metabolic pathways. A positive correlation was found between COX activity and α1-PI (R=0.51, p=0.025). A significant decrease in faCS compared to control (p=0.0003) and a negative correlation between faCS and GST activity (R=-0.496, p=0.011) were observed. faCS was positively correlated with the degree of reduction in the PANSS score (R=0.416, p=0.038).ConclusionsThe revealed connection between molecular and cellular components of the immune system in patients with endogenous psychoses reflect activation of the systemic inflammatory response accompanied by changes in the ratio of monocyte subpopulations and impaired regulation of the complement system. The data obtained can be used to develop methods of monitoring patients taking into account their immunological features.Disclosure of InterestNone Declared

The pathological function of neutrophils in pemphigoid diseases

Abstract Pemphigoid diseases (PDs) are a group of autoimmune blistering diseases, including bullous pemphigoid, epidermolysis bullosa acquisita, mucous membrane pemphigoid, linear immunoglobulin A disease, and other rare variants. These diseases are characterized by the presence of autoantibodies that target proteins at the dermal-epidermal junction, resulting in the formation of tense blisters and erosions on the skin and/or mucosa. The current therapeutic approaches, such as systemic corticosteroid, are associated with significant adverse effects, highlighting that safer and more effective treatment options are an urgent clinical need. To address this unmet need, a comprehensive understanding of the detailed mechanisms underlying PDs is essential. Based on their histopathological infiltration in pemphigoid lesions, neutrophils have long been implicated as major contributors to the initiation and progression of the diseases. Numerous in vivo and in vitro studies have investigated the role of neutrophils in the pemphigoid pathology, revealing various pathological mechanisms induced by these cells, including the release of neutrophil elastase and matrix metalloproteinase-9, as well as the formation of neutrophil extracellular traps. The present review provides a comprehensive summary and critical evaluation of the current understanding regarding the role of neutrophils in PDs. In addition, it discusses the potential of targeting neutrophil-associated pathways as a novel therapeutic approach for the diseases.

Gasdermin D promotes influenza virus-induced mortality through neutrophil amplification of inflammation

Influenza virus activates cellular inflammasome pathways, which can be both beneficial and detrimental to infection outcomes. Here, we investigate the function of the inflammasome-activated, pore-forming protein gasdermin D (GSDMD) during infection. Ablation of GSDMD in knockout (KO) mice (Gsdmd−/−) significantly attenuates influenza virus-induced weight loss, lung dysfunction, lung histopathology, and mortality compared with wild type (WT) mice, despite similar viral loads. Infected Gsdmd−/− mice exhibit decreased inflammatory gene signatures shown by lung transcriptomics. Among these, diminished neutrophil gene activation signatures are corroborated by decreased detection of neutrophil elastase and myeloperoxidase in KO mouse lungs. Indeed, directly infected neutrophils are observed in vivo and infection of neutrophils in vitro induces release of DNA and tissue-damaging enzymes that is largely dependent on GSDMD. Neutrophil depletion in infected WT mice recapitulates the reductions in mortality, lung inflammation, and lung dysfunction observed in Gsdmd−/− animals, while depletion does not have additive protective effects in Gsdmd−/− mice. These findings implicate a function for GSDMD in promoting lung neutrophil responses that amplify influenza virus-induced inflammation and pathogenesis. Targeting the GSDMD/neutrophil axis may provide a therapeutic avenue for treating severe influenza.

The Dual Role of Neutrophil Extracellular Traps (NETs) in Sepsis and Ischemia-Reperfusion Injury: Comparative Analysis across Murine Models.

A better understanding of the function of neutrophil extracellular traps (NETs) may facilitate the development of interventions for sepsis. The study aims to investigate the formation and degradation of NETs in three murine sepsis models and to analyze the production of reactive oxygen species (ROS) during NET formation. Murine sepsis was induced by midgut volvulus (720° for 15 min), cecal ligation and puncture (CLP), or the application of lipopolysaccharide (LPS) (10 mg/kg body weight i.p.). NET formation and degradation was modulated using mice that were genetically deficient for peptidyl arginine deiminase-4 (PAD4-KO) or DNase1 and 1L3 (DNase1/1L3-DKO). After 48 h, mice were killed. Plasma levels of circulating free DNA (cfDNA) and neutrophil elastase (NE) were quantified to assess NET formation and degradation. Plasma deoxyribonuclease1 (DNase1) protein levels, as well as tissue malondialdehyde (MDA) activity and glutathione peroxidase (GPx) activity, were quantified. DNase1 and DNase1L3 in liver, intestine, spleen, and lung tissues were assessed. The applied sepsis models resulted in a simultaneous increase in NET formation and oxidative stress. NET formation and survival differed in the three models. In contrast to LPS and Volvulus, CLP-induced sepsis showed a decreased and increased 48 h survival in PAD4-KO and DNase1/1L3-DKO mice, when compared to WT mice, respectively. PAD4-KO mice showed decreased formation of NETs and ROS, while DNase1/1L3-DKO mice with impaired NET degradation accumulated ROS and chronicled the septic state. The findings indicate a dual role for NET formation and degradation in sepsis and ischemia-reperfusion (I/R) injury: NETs seem to exhibit a protective capacity in certain sepsis paradigms (CLP model), whereas, collectively, they seem to contribute adversely to scenarios where sepsis is combined with ischemia-reperfusion (volvulus).

Anti-inflammatory effect and pharmacokinetics of dehydroandrographolide, an active component of Andrographis paniculata, on Poly(I:C)-induced acute lung injury

Acute lung injury (ALI) is a common and critical respiratory disorder caused by various factors, with viral infection being the leading contributor. Dehydroandrographolide (DAP), a constituent of the Chinese herbal plant Andrographis paniculata, exhibits a range of activities including anti-inflammatory, in vitro antiviral and immune-enhancing effects. This study evaluated the anti-inflammatory effects and pharmacokinetics (PK) profile of DAP in ALI mice induced by intratracheal instillation of Poly(I:C) (PIC). The results showed that oral administration of DAP (10–40 mg/kg) effectively suppressed the increase in lung wet–dry weight ratio, total cells, total protein content, accumulation of immune cells, inflammatory cytokines and neutrophil elastase levels in bronchoalveolar lavage fluid of PIC-treated mice. DAP concentrations, determined by an LC-MS/MS method, in plasma after receiving DAP (20 mg/kg) were unchanged compared to those in normal mice. However, DAP concentrations and relative PK parameters in the lungs were significantly altered in PIC-treated mice, exhibiting a relatively higher maximum concentration, larger AUC, and longer elimination half-life than those in the lungs of normal mice. These results demonstrated that DAP could improve lung edema and inflammation in ALI mice, and suggested that lung injury might influence the PK properties of DAP, leading to increased lung distribution and residence. Our study provides evidence that DAP displays significant anti-inflammatory activity against viral lung injury and is more likely to distribute to damaged lung tissue.

Association of the immediate perioperative dynamics of circulating DNA levels and neutrophil extracellular traps formation in cancer patients.

Elevated circulating DNA (cirDNA) concentrations were found to be associated with trauma or tissue damage which suggests involvement of inflammation or cell death in post-operative cirDNA release. We carried out the first prospective, multicenter study of the dynamics of cirDNA and neutrophil extracellular trap (NETs) markers during the perioperative period from 24 h before surgery up to 72 h after curative surgery in cancer patients. We examined the plasma levels of two NETs protein markers [myeloperoxidase (MPO) and neutrophil elastase (NE)], as well as levels of cirDNA of nuclear (cir-nDNA) and mitochondrial (cir-mtDNA) origin in 29 colon, prostate, and breast cancer patients and in 114 healthy individuals (HI). The synergistic analytical information provided by these markers revealed that: (i) NETs formation contributes to post-surgery conditions; (ii) post-surgery cir-nDNA levels were highly associated with NE and MPO in colon cancer [r=0.60 (P<0.001) and r=0.53 (P<0.01), respectively], but not in prostate and breast cancer; (iii) each tumor type shows a specific pattern of cir-nDNA and NETs marker dynamics, but overall the pre- and post-surgery median values of cir-nDNA, NE, and MPO were significantly higher in cancer patients than in HI. Taken as a whole, our work reveals the association of NETs formation with the elevated cir-nDNA release during a cancer patient's perioperative period, depending on surgical procedure or cancer type. By contrast, cir-mtDNA is poorly associated with NETs formation in the studied perioperative period, which would appear to indicate a different mechanism of release or suggest mitochondrial dysfunction.

Immature neutrophils in cord blood exert increased expression of genes associated with antimicrobial function.

The immune systems of both the mother and the newborn face significant challenges during birth. Proper immune regulation after birth is essential for the survival of neonates. Numerous studies have demonstrated that the neonatal immune system is relatively immature, particularly in its adaptive arm, placing the primary responsibility for immune surveillance on innate immunity. Given the significant role of neutrophils in protecting the neonate after birth, we conducted a study investigating the properties of neutrophils in newborn cord blood using various methodological approaches. Our findings demonstrate the presence of immature low-density neutrophils in the cord blood, which are likely responsible for the observed elevated expression of genes coding for proteins essential to antimicrobial response, including myeloperoxidase, neutrophils elastase, and defensins. We propose that these cells function normally and support the protection of newborns early after birth. Furthermore, our results suggest that the mode of delivery might significantly influence the programming of neutrophil function. The presented findings emphasize the importance of distinct neutrophil subpopulations in neonatal immunity and their potential impact on early postnatal health.

Reorganization of the actin cytoskeleton during the formation of neutrophil extracellular traps (NETs)

We analyzed actin cytoskeleton alterations during NET extrusion by neutrophil-like dHL-60 cells and human neutrophils in the absence of DNase1 containing serum to avoid chromatin degradation and microfilament disassembly. NET-formation by dHL-60 cells and neutrophils was induced by Ionomycin or phorbol-12-myristat-13-acetate (PMA). Subsequent staining with anti-actin and TRITC-phalloidin showed depolymerization of the cortical F-actin at spatially confined areas, the NET extrusion sites, effected by transient activation of the monooxygenase MICAL-1 supported by the G-actin binding proteins cofilin, profilin, thymosin ß4 and probably the F-actin fragmenting activity of gelsolin and/or its fragments, which also decorated the formed NETs. MICAL-1 itself appeared to be proteolyzed by neutrophil elastase possibly to confine its activity to the NET-extrusion area. The F-actin oxidization activity of MICAL-1 is inhibited by Levosimendan leading to reduced NET-formation. Anti-gasdermin-D immunohistochemistry showed a cytoplasmic distribution in non-stimulated cells. After stimulation the NET-extrusion pore displayed reduced anti-gasdermin-D staining but accumulated underneath the plasma membrane of the remaining cell body. A similar distribution was observed for myosin that concentrated together with cortical F-actin along the periphery of the remaining cell body suggesting force production by acto-myosin interactions supporting NET expulsion as indicated by the inhibitory action of the myosin ATPase inhibitor blebbistatin. Isolated human neutrophils displayed differences in their content of certain cytoskeletal proteins. After stimulation neutrophils with high gelsolin content preferentially formed “cloud”-like NETs, whereas those with low or no gelsolin formed long “filamentous” NETs.