The Role of Reactive Oxygen Species (ROS) in the Formation of Extracellular Traps (ETs) in Humans

Extracellular traps (ETs) are reticulate structures of extracellular DNA associated with antimicrobial molecules. Their formation by phagocytes (mainly by neutrophils: NETs) has been identified as an essential element of vertebrate innate immune defense. However, as ETs are also toxic to host cells and potent triggers of autoimmunity, their role between pathogen defense and human pathogenesis is ambiguous, and they contribute to a variety of acute and chronic inflammatory diseases. Since the discovery of ET formation (ETosis) a decade ago, evidence has accumulated that most reaction cascades leading to ET release involve ROS. An important new facet was added when it became apparent that ETosis might be directly linked to, or be a variant of, the autophagy cell death pathway. The present review analyzes the evidence to date on the interplay between ROS, autophagy and ETosis, and highlights and discusses several further aspects of the ROS-ET relationship that are incompletely understood. These aspects include the role of NADPH oxidase-derived ROS, the molecular requirements of NADPH oxidase-dependent ETosis, the roles of NADPH oxidase subtypes, extracellular ROS and of ROS from sources other than NADPH oxidase, and the present evidence for ROS-independent ETosis. We conclude that ROS interact with ETosis in a multidimensional manner, with influence on whether ETosis shows beneficial or detrimental effects

The Role of Reactive Oxygen Species (ROS) in the Formation of Extracellular Traps (ETs) in Humans

Extracellular traps (ETs) are reticulate structures of extracellular DNA associated with antimicrobial molecules. Their formation by phagocytes (mainly by neutrophils: NETs) has been identified as an essential element of vertebrate innate immune defense. However, as ETs are also toxic to host cells and potent triggers of autoimmunity, their role between pathogen defense and human pathogenesis is ambiguous, and they contribute to a variety of acute and chronic inflammatory diseases. Since the discovery of ET formation (ETosis) a decade ago, evidence has accumulated that most reaction cascades leading to ET release involve ROS. An important new facet was added when it became apparent that ETosis might be directly linked to, or be a variant of, the autophagy cell death pathway. The present review analyzes the evidence to date on the interplay between ROS, autophagy and ETosis, and highlights and discusses several further aspects of the ROS-ET relationship that are incompletely understood. These aspects include the role of NADPH oxidase-derived ROS, the molecular requirements of NADPH oxidase-dependent ETosis, the roles of NADPH oxidase subtypes, extracellular ROS and of ROS from sources other than NADPH oxidase, and the present evidence for ROS-independent ETosis. We conclude that ROS interact with ETosis in a multidimensional manner, with influence on whether ETosis shows beneficial or detrimental effects

Rehabilitation Process and Outcome / Extracorporeal Shock Wave Therapy in Acute Injury Care : A Systematic Review

Objectives: We provide a systematic review of the literature to identify clinical studies assessing the effects of extracorporeal shock wave therapy (ESWT) on acutely injured tissues of human subjects, also highlighting the biological mechanisms by which the technique is proposed to promote the processes of early tissue repair. Special attention is also paid to the progress of research in animal models. Method: A systematic review of the literature on ESWT of acute injuries of bone and soft tissue as available in the PubMed/MEDLINE, Cochrane CENTRAL, SPORTDiscus, and CINAHL databases up to December 2017 was conducted. Results: A total of 10 studies were included. There is some evidence for the application of ESWT in an early postacute injury phase. Most studies report benefits with no or minimal side effects. However, different types of treated tissues and wounds (varying cause and severity) and resulting heterogeneity in study design and outcome measurement make it difficult to compare studies. The picture of knowledge remains limited by an apparent lack of data on optimal treatment timing and on tissue- and injury-specific parameters. Conclusions: Although the amount of studies to date is still limited, recent clinical research has presented first successful steps to introduce ESWT as a means of treatment in acute injury care. Therefore, on the basis of the analyzed data, further testing is encouraged to validate optimal timing, physical settings, and possible long-term effects to exclude potential risks.(VLID)289561

Biomolecules / The role of reactive oxygen species (ROS) in the formation of extracellular traps (ETs) in humans

Extracellular traps (ETs) are reticulate structures of extracellular DNA associated with antimicrobial molecules. Their formation by phagocytes (mainly by neutrophils: NETs) has been identified as an essential element of vertebrate innate immune defense. However, as ETs are also toxic to host cells and potent triggers of autoimmunity, their role between pathogen defense and human pathogenesis is ambiguous, and they contribute to a variety of acute and chronic inflammatory diseases. Since the discovery of ET formation (ETosis) a decade ago, evidence has accumulated that most reaction cascades leading to ET release involve ROS. An important new facet was added when it became apparent that ETosis might be directly linked to, or be a variant of, the autophagy cell death pathway. The present review analyzes the evidence to date on the interplay between ROS, autophagy and ETosis, and highlights and discusses several further aspects of the ROS-ET relationship that are incompletely understood. These aspects include the role of NADPH oxidase-derived ROS, the molecular requirements of NADPH oxidase-dependent ETosis, the roles of NADPH oxidase subtypes, extracellular ROS and of ROS from sources other than NADPH oxidase, and the present evidence for ROS-independent ETosis. We conclude that ROS interact with ETosis in a multidimensional manner, with influence on whether ETosis shows beneficial or detrimental effects

International Journal of Legal Medicine / Postmortem degradation of skeletal muscle proteins : a novel approach to determine the time since death

Estimating the time since death is a very important aspect in forensic sciences which is pursued by a variety of methods. The most precise method to determine the postmortem interval (PMI) is the temperature method which is based on the decrease of the body core temperature from 37 C. However, this method is only useful in the early postmortem phase (036 h). The aim of the present work is to develop an accurate method for PMI determination beyond this present limit. For this purpose, we used sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting, and casein zymography to analyze the time course of degradation of selected proteins and calpain activity in porcine biceps femoris muscle until 240 h postmortem (hpm). Our results demonstrate that titin, nebulin, desmin, cardiac troponin T, and SERCA1 degraded in a regular and predictable fashion in all samples investigated. Similarly, both the native calpain 1 and calpain 2 bands disintegrate into two bands subsequently. This degradation behavior identifies muscular proteins and enzymes as promising substrates for future molecular-based PMI determination technologies

The Initial Inflammatory Response to Bioactive Implants Is Characterized by NETosis

<div><p>Implants trigger an inflammatory response, which is important for osseointegration. Here we studied neutrophil extracellular trap (NET) release of human neutrophils in response to sandblasted large-grit acid etched (SLA) implants using fluorescent, confocal laser scanning and scanning electron microscopy. Our studies demonstrate that human neutrophils rapidly adhered to SLA surfaces, which triggered histone citrullination and NET release. Further studies showed that albumin or acetylsalicylic acid had no significant effects on the inflammatory response to SLA surfaces. In contrast to bioinert materials, which do not osseointegrate, the bioactivity of SLA surfaces is coupled with the ability to release NETs. Further investigations are necessary for clarifying the role of NETosis for osseointegration.</p></div

Neutrophil extracellular trap (NET) formation characterises stable and exacerbated COPD and correlates with airflow limitation

<span>Background: COPD is a progressive disease of the airways that is characterized by </span><span class="searchterm">neutrophilic</span><span> inflammation, a condition known to promote the excessive formation of </span><span class="searchterm">neutrophil</span><span> extracellular traps (NETs). The presence of large amounts of NETs has recently been demonstrated for a variety of inflammatory lung diseases including cystic fibrosis, asthma and exacerbated COPD. Objective: We test whether excessive NET generation is restricted to exacerbation of COPD or whether it also occurs during stable periods of the disease, and whether NET presence and amount correlates with the severity of airflow limitation. Patients, materials and methods: Sputum samples from four study groups were examined: COPD patients during acute exacerbation, patients with stable disease, and smoking and non-smoking controls without airflow limitation. Sputum induction followed the ECLIPSE protocol. Confocal laser microscopy (CLSM) and electron microscopy were used to analyse samples. Immunolabelling and fluorescent DNA staining were applied to trace NETs and related marker proteins. CLSM specimens served for quantitative evaluation. Results: Sputum of COPD patients is clearly characterised by NETs and NET-forming </span><span class="searchterm">neutrophils</span><span>. The presence of large amounts of NET is associated with disease severity ( p < 0.001): over 90 % in exacerbated COPD, 45 % in stable COPD, and 25 % in smoking controls, but less than 5 % in non-smokers. Quantification of NET-covered areas in sputum preparations confirms these results. Conclusions: NET formation is not confined to exacerbation but also present in stable COPD and correlates with the severity of airflow limitation. We infer that NETs are a major contributor to chronic inflammatory and lung tissue damage in COPD.</span

Cell adhesion to SLA surfaces from whole peripheral blood with different pre-treatments.

<p>(A) Representative images of the three pre-treatment groups (blue: DAPI, green: NE, red: CitH3), scale bar: 20μm. (B-F) Boxplots (interquartile range; line: median, whiskers: 1.5 x interquartile range) showing absolute (B-D) and relative (E) cell numbers and the areas covered by NETs (F) for the three groups. Superscript letters indicate groups of statistically significant differences. The three types of treatment were compared by univariate analysis of variance and by Tukey HSD post hoc test with subject and sampling session as covariates,. Superscript letters (a, b) indicate groups of statistically significant differences at the <i>P</i><0.05 level (similar letters: no significant differences, different letters: significant difference).</p

International Journal of Legal Medicine / First application of a protein-based approach for time since death estimation

Awareness of postmortem degradation processes in a human body is fundamental to develop methods for forensic time since death estimation (TDE). Currently, applied approaches are all more or less limited to certain postmortem phases, or have restrictions on behalf of circumstances of death. Novel techniques, however, rarely exceed basic research phases due to various reasons. We report the first application of a novel method, based on decay of muscle proteins, in a recent case of murder-suicide, where other TDE methods failed to obtain data. We detected considerably different protein degradation profiles in both individuals involved and compared the data to our presently available database. We obtained statistical evidence for un-simultaneous death and therefore received valuable information to trace the progression of events based on protein degradation. Although we could not sensibly convert the data to respective times of death, this case highlights the potential for future application and elucidates the necessary further steps to develop a viable TDE method