­­­­­­­A type I IFN, prothrombotic hyperinflammatory neutrophil signature is distinct for COVID-19 ARDS­­­

Background: Acute respiratory distress syndrome (ARDS) is a severe critical condition with a high mortality that is currently in focus given that it is associated with mortality caused by coronavirus disease 2019 (COVID-19). Neutrophils play a key role in the lung injury characteristic of non-COVID-19 ARDS and there is also accumulating evidence of neutrophil mediated lung injury in patients who succumb to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: We undertook a functional proteomic and metabolomic survey of circulating neutrophil populations, comparing patients with COVID-19 ARDS and non-COVID-19 ARDS to understand the molecular basis of neutrophil dysregulation. Results: Expansion of the circulating neutrophil compartment and the presence of activated low and normal density mature and immature neutrophil populations occurs in ARDS, irrespective of cause. Release of neutrophil granule proteins, neutrophil activation of the clotting cascade and upregulation of the Mac-1 platelet binding complex with formation of neutrophil platelet aggregates is exaggerated in COVID-19 ARDS. Importantly, activation of components of the neutrophil type I interferon responses is seen in ARDS following infection with SARS-CoV-2, with associated rewiring of neutrophil metabolism, and the upregulation of antigen processing and presentation. Whilst dexamethasone treatment constricts the immature low density neutrophil population, it does not impact upon prothrombotic hyperinflammatory neutrophil signatures. Conclusions: Given the crucial role of neutrophils in ARDS and the evidence of a disordered myeloid response observed in COVID-19 patients, this work maps the molecular basis for neutrophil reprogramming in the distinct clinical entities of COVID-19 and non-COVID-19 ARDS.

98 The Epidemiology of Acute Stress Disorder Among Inpatient Adult Patients with Burn Injury

Introduction Burn injured patients are at high risk for developing Acute Stress Disorder (ASD) and Posttraumatic Stress Disorder (PTSD) following injury. ASD itself is a reliable predictor for the development of PTSD, which usually persists once established. Injury-related characteristics in burn patients (TBSA and anatomic location of burn) do not predict the development of psychological trauma. There is a paucity of literature examining acute psychosocial evaluations of patients with burn injury to address the need for early interventions. Behavioral health assessment and treatment in burn centers may foster improved detection and management of ASD among a variety of other mental health conditions. The goal of this study is to investigate the demographic and injury characteristics associated with new ASD diagnoses in a cohort of inpatient burn survivors. Methods Burn injured patients who were admitted to a regional burn center between June 2019 and June 2020 and referred for burn psychology evaluation were retrospectively reviewed. Minors, non-burn injured patients, and those with incomplete evaluations were excluded. Demographic, injury characteristic, health history, and psychologic evaluation results were collected from the medical record. ASD diagnosis was defined by criteria outlined in the PTSD Checklist for DSM-5 (PCL-5). Demographic and injury characteristic were compared between patients with and without ASD diagnoses. Statistical analysis was performed with Mann-Whitney, Chi-square, and Fisher’s Exact test as appropriate. Significance was set at a p=0.05. Results Fifty-two patients with median age of 49.5 (IQR, 29–62) years and median TBSA of 6 (2.8–14.4) % met inclusion criteria. Of these, 11 (21%) patients were diagnosed with ASD. Patients with ASD were more often female, (73% vs. 29%, p=0.01), younger (38.5 years vs. 46 years, p=0.05), involved in a structural fire (45.5% vs. 10%, p=0.01), and employed at the time of injury (63% vs. 14.6%, p=0.002). There were no significant differences between groups in TBSA, hospital length of stay, ICU admission, or proportion of patients requiring operative intervention. Among patients who required operative intervention, those in the ASD group underwent fewer total procedures (1 vs. 4, p=0.05). Conclusions Patients who developed ASD were younger, more likely female, more often involved in structural fires, and employed. Markers of injury severity such as TBSA, need for operative intervention, ICU admission and hospital length of stay were not associated with the development of ASD.

­­­­­­­A type I IFN, prothrombotic hyperinflammatory neutrophil signature is distinct for COVID-19 ARDS­­­

Background: Acute respiratory distress syndrome (ARDS) is a severe critical condition with a high mortality that is currently in focus given that it is associated with mortality caused by coronavirus disease 2019 (COVID-19). Neutrophils play a key role in the lung injury characteristic of non-COVID-19 ARDS and there is also accumulating evidence of neutrophil mediated lung injury in patients who succumb to infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods: We undertook a functional proteomic and metabolomic survey of circulating neutrophil populations, comparing patients with COVID-19 ARDS and non-COVID-19 ARDS to understand the molecular basis of neutrophil dysregulation. Results: Expansion of the circulating neutrophil compartment and the presence of activated low and normal density mature and immature neutrophil populations occurs in ARDS, irrespective of cause. Release of neutrophil granule proteins, neutrophil activation of the clotting cascade and upregulation of the Mac-1 platelet binding complex with formation of neutrophil platelet aggregates is exaggerated in COVID-19 ARDS. Importantly, activation of components of the neutrophil type I interferon responses is seen in ARDS following infection with SARS-CoV-2, with associated rewiring of neutrophil metabolism, and the upregulation of antigen processing and presentation. Whilst dexamethasone treatment constricts the immature low density neutrophil population, it does not impact upon prothrombotic hyperinflammatory neutrophil signatures. Conclusions: Given the crucial role of neutrophils in ARDS and the evidence of a disordered myeloid response observed in COVID-19 patients, this work maps the molecular basis for neutrophil reprogramming in the distinct clinical entities of COVID-19 and non-COVID-19 ARDS.

Characteristic Curves and Criterion of Critical Difference in Assessing the Informativeness of Markers of Renal Damage in Lithotripsy

Aim of study. Determination of the diagnostic significance of laboratory biomarkers of renal tissue damage in remote nephrolithotripsy in patients with urolithiasis.Material and methods. On the basis of the urology department of the Republican Clinical Hospital (Ufa), 35 patients with urolithiasis were examined, who underwent remote shock wave lithotripsy sessions. The laboratory parameters were determined in patients: the number of erythrocytes, leukocytes in the blood, the level of lipocalin and microalbumin in the urine, as well as alpha2-microglobulin and cystatin C in the blood serum. The control group included 14 healthy donors. To determine the diagnostic efficacy of biomarkers of renal injury, characteristic curves were plotted, and lipocalin level shifts were interpreted taking into account the data on the critical difference criterion value.Results. When studying the urinary level of lipocalin in patients with urolithiasis, it was found that the difference in the concentration of the biomarker in them and in healthy individuals is statistically insignificant (0.68 pg/ml versus 0.4 pg/ml). After the first session of extracorporeal lithotripsy, an increase in urinary excretion of lipocalin by 5 times is noted, after the second - by an additional 1.6 times, and after the third - by another 1.7 times (the differences are statistically significant). To analyze the prognostic efficiency of markers of renal injury, characteristic curves were plotted. The area under the ROC curve for lipocalin varied from 0.77 to 0.80 depending on the number of sessions, which indicates a high diagnostic efficiency of this biomarker. The determination of the criterion of critical difference (CCD) showed that an increase in the level of lipocalin in the urine after the first session of lithotripsy more than 2.1 times is statistically significant. The concentration of the specified biomarker in urine exceeding 4.5 pg/ml, 6 pg/ml and 10 pg/ml after the first, second and third sessions of lithotripsy, respectively, can be considered as a basis for changing treatment tactics (delaying the second procedure) or performing lithotripsy in another way.Conclusion. Urinary lipocalin, associated with neutrophil gelatinase, is an informative biomarker of renal injury in the assessment of complications associated with the lithotripsy procedure.

Proteomics identifies a type I IFN, prothrombotic hyperinflammatory circulating COVID-19 neutrophil signature distinct from non-COVID-19 ARDS

Understanding the mechanisms by which infection with SARS-CoV-2 leads to acute respiratory distress syndrome (ARDS) is of significant clinical interest given the mortality associated with severe and critical coronavirus induced disease 2019 (COVID-19). Neutrophils play a key role in the lung injury characteristic of non-COVID-19 ARDS, but a relative paucity of these cells is observed at post-mortem in lung tissue of patients who succumb to infection with SARS-CoV-2. With emerging evidence of a dysregulated innate immune response in COVID-19, we undertook a functional proteomic survey of circulating neutrophil populations, comparing patients with COVID-19 ARDS, non-COVID-19 ARDS, moderate COVID-19, and healthy controls. We observe that expansion of the circulating neutrophil compartment and the presence of activated low and normal density mature and immature neutrophil populations occurs in both COVID-19 and non-COVID-19 ARDS. In contrast, release of neutrophil granule proteins, neutrophil activation of the clotting cascade and formation of neutrophil platelet aggregates is significantly increased in COVID-19 ARDS. Importantly, activation of components of the neutrophil type I IFN responses is specific to infection with SARS-CoV-2 and linked to metabolic rewiring. Together this work highlights how differential activation of circulating neutrophil populations may contribute to the pathogenesis of ARDS, identifying processes that are specific to COVID-19 ARDS.

Immunometabolic modulation of retinal inflammation by CD36 ligand

In subretinal inflammation, activated mononuclear phagocytes (MP) play a key role in the progression of retinopathies. Little is known about the mechanism involved in the loss of photoreceptors leading to vision impairment. Studying retinal damage induced by photo-oxidative stress, we observed that cluster of differentiation 36 (CD36)-deficient mice featured less subretinal MP accumulation and attenuated photoreceptor degeneration. Moreover, treatment with a CD36-selective azapeptide ligand (MPE-001) reduced subretinal activated MP accumulation in wild type mice and preserved photoreceptor layers and function as assessed by electroretinography in a CD36-dependent manner. The azapeptide modulated the transcriptome of subretinal activated MP by reducing pro-inflammatory markers. In isolated MP, MPE-001 induced dissociation of the CD36-Toll-like receptor 2 (TLR2) oligomeric complex, decreasing nuclear factor-kappa B (NF-κB) and NLR family pyrin domain containing 3 (NLRP3) inflammasome activation. In addition, MPE-001 caused an aerobic metabolic shift in activated MP, involving peroxisome proliferator-activated receptor-γ (PPAR-γ) activation, which in turn mitigated inflammation. Accordingly, PPAR-γ inhibition blocked the cytoprotective effect of MPE-001 on photoreceptor apoptosis elicited by activated MP. By altering activated MP metabolism, MPE-001 decreased immune responses to alleviate subsequent inflammation-dependent neuronal injury characteristic of various vision-threatening retinal disorders.

Pseudomonas aeruginosa exoenzymes U and Y induce a transmissible endothelial proteinopathy

We tested the hypothesis that Pseudomonas aeruginosa type 3 secretion system effectors exoenzymes Y and U (ExoY and ExoU) induce release of a high-molecular-weight endothelial tau, causing transmissible cell injury characteristic of an infectious proteinopathy. Both the bacterial delivery of ExoY and ExoU and the conditional expression of an activity-attenuated ExoU induced time-dependent pulmonary microvascular endothelial cell gap formation that was paralleled by the loss of intracellular tau and the concomitant appearance of high-molecular-weight extracellular tau. Transfer of the high-molecular-weight tau in filtered supernatant to naïve endothelial cells resulted in intracellular accumulation of tau clusters, which was accompanied by cell injury, interendothelial gap formation, decreased endothelial network stability in Matrigel, and increased lung permeability. Tau oligomer monoclonal antibodies captured monomeric tau from filtered supernatant but did not retrieve higher-molecular-weight endothelial tau and did not rescue the injurious effects of tau. Enrichment and transfer of high-molecular-weight tau to naïve cells was sufficient to cause injury. Thus we provide the first evidence for a pathophysiological stimulus that induces release and transmissibility of high-molecular-weight endothelial tau characteristic of an endothelial proteinopathy.

Natural Antioxidant Betanin Protects Rats from Paraquat-Induced Acute Lung Injury Interstitial Pneumonia

The effect of betanin on a rat paraquat-induced acute lung injury (ALI) model was investigated. Paraquat was injected intraperitoneally at a single dose of 20 mg/kg body weight, and betanin (25 and 100 mg/kg/d) was orally administered 3 days before and 2 days after paraquat administration. Rats were sacrificed 24 hours after the last betanin dosage, and lung tissue and bronchoalveolar lavage fluid (BALF) were collected. In rats treated only with paraquat, extensive lung injury characteristic of ALI was observed, including histological changes, elevation of lung : body weight ratio, increased lung permeability, increased lung neutrophilia infiltration, increased malondialdehyde (MDA) and myeloperoxidase (MPO) activity, reduced superoxide dismutase (SOD) activity, reduced claudin-4 and zonula occluden-1 protein levels, increased BALF interleukin (IL-1) and tumor necrosis factor (TNF)-αlevels, reduced BALF IL-10 levels, and increased lung nuclear factor kappa (NF-κB) activity. In rats treated with betanin, paraquat-induced ALI was attenuated in a dose-dependent manner. In conclusion, our results indicate that betanin attenuates paraquat-induced ALI possibly via antioxidant and anti-inflammatory mechanisms. Thus, the potential for using betanin as an auxilliary therapy for ALI should be explored further.