Autoantibodies against SUMO1-DHX35 in long-COVID.

Long COVID is a collection of symptoms as a late sequelae of SARS-CoV-2 infection. It often includes mental symptoms such as cognitive symptoms, persisting loss of smell and taste, in addition to exertional dyspnea. A role of various autoantibodies (autoAbs) has been postulated in long-COVID and is being further investigated. With the goal of identifying potentially unknown autoAbs, we screened plasma of patients with long COVID on in-house post-translationally modified protein macroarrays including citrullinated, SUMOylated and acetylated membranes. SUMO1ylated isoform DEAD/H (Asp-Glu-Ala-Asp/His) box helicase 35 (SUMO1-DHX35) was identified as only candidate antigen. In adult patients with long COVID, IgG autoAbs against SUMO1-DHX35 of IgG class were found in seven of 71 (9.8%) plasma samples, of IgM and IgG class in one of 69 (1.4%) samples, not in 200 healthy adult controls, not in 442 healthy children, and 146 children after SARS-CoV-2 infection. All autoAb-positive seven patients were female. AutoAb titers ranged between 200 to up to 400 By point mutagenesis and expression of FLAG-tagged mutants of DHX35 in HEK293 cells, and subsequent SUMOylation of purified constructs, lysine 53 was identified as a unique, never yet identified, SUMOylation site. The autoAbs had no reactivity against the non-SUMO1ylated mutant (K53R) of DHX35. To summarize, autoAbs against SUMO1-DHX35 were identified in adult female patients with long-COVID. Further studies are needed to verify the frequency of occurrence. The function of DHX35 has not yet been determined and there is no available information in relation to disease implication. The molecular mechanism causing the SUMOylation, the potential functional consequences of this post-translational modification on DHX35, and a potential pathogenicity of the autoAbs against SUMO1-DHX35 in COVID-19 and other possible contexts remain to be elucidated.

Concentrations of Soluble Angiotensin Converting Enzyme 2 (sACE2) in Children and Adults with and without COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing the coronavirus disease 2019 (COVID-19) pandemic, leads to illness and death. Various risk factors for a severe course, such as higher age, male gender and pre-existing illnesses are known. However, pathophysiological risk factors are largely unclear. Notably, the mild course of disease in children is conspicuous. Angiotensin converting enzyme 2 (ACE2) serves as a receptor for SARS-CoV-2 and is a key enzyme in infection. Differences in the distribution of ACE2 can provide insights into different courses of COVID-19. Our aim was to elucidate the role of ACE2 as a pathophysiological risk factor by measuring soluble ACE2 (sACE2) via ELISA in blood samples (lithium-heparin-plasma or serum) of 367 individuals including children and adults with and without COVID-19. sACE2-levels were compared between the groups according to age and sex. In adults and children with COVID-19, sACE2-concentrations are significantly higher compared to healthy individuals. sACE2-levels increase with age and are lower in children compared to adults with COVID-19. Sex doesn't significantly influence sACE2-concentration. It remains unclear whether sACE2 concentrations increase because of the infection and what factors could influence this response. In conclusion, the increase of sACE2-concentration with age could indicate that ACE2 concentrations mirror increased COVID-19 severity.

Plasma Metabolome Alterations Discriminate between COVID-19 and Non-COVID-19 Pneumonia.

Pneumonia is a common cause of morbidity and mortality and is most often caused by bacterial pathogens. COVID-19 is characterized by lung infection with potential progressive organ failure. The systemic consequences of both disease on the systemic blood metabolome are not fully understood. The aim of this study was to compare the blood metabolome of both diseases and we hypothesize that plasma metabolomics may help to identify the systemic effects of these diseases. Therefore, we profiled the plasma metabolome of 43 cases of COVID-19 pneumonia, 23 cases of non-COVID-19 pneumonia, and 26 controls using a non-targeted approach. Metabolic alterations differentiating the three groups were detected, with specific metabolic changes distinguishing the two types of pneumonia groups. A comparison of venous and arterial blood plasma samples from the same subjects revealed the distinct metabolic effects of pulmonary pneumonia. In addition, a machine learning signature of four metabolites was predictive of the disease outcome of COVID-19 subjects with an area under the curve (AUC) of 86 ± 10 %. Overall, the results of this study uncover systemic metabolic changes that could be linked to the etiology of COVID-19 pneumonia and non-COVID-19 pneumonia.

Glycyrrhizin through liquorice intake modulates ACE2 and HMGB1 levels-A pilot study in healthy individuals with implications for COVID-19 and ARDS.

BACKGROUND: Glycyrrhizin, an active component of liquorice root extract, exhibits antiviral and immunomodulatory properties by direct inhibition of the pro-inflammatory alarmin HMGB1 (High-mobility group box 1). OBJECTIVE: The aim of this study was to explore the role of liquorice intake on the viral entry receptor ACE2 (angiotensin-converting enzyme 2) and the immunoregulatory HMGB1 in healthy individuals and to explore HMGB1 expression in coronavirus disease 2019 (COVID-19) or non-COVID-19 in ARDS (acute respiratory distress syndrome patients). MATERIAL AND METHODS: This study enrolled 43 individuals, including hospitalised patients with i) acute respiratory distress syndrome (ARDS) due to COVID-19 (n = 7) or other underlying causes (n = 12), ii) mild COVID-19 (n = 4) and iii) healthy volunteers (n = 20). Healthy individuals took 50 g of liquorice (containing 3% liquorice root extract) daily for 7 days, while blood samples were collected at baseline and on day 3 and 7. Changes in ACE2 and HMGB1 levels were determined by Western blot analysis and enzyme-linked immunosorbent assay, respectively. Additionally, HMGB1 levels were measured in hospitalised COVID-19 patients with mild disease or COVID-19 associated acute respiratory distress syndrome (ARDS) and compared with a non-COVID-19-ARDS group. RESULTS: Liquorice intake significantly reduced after 7 days both cellular membranous ACE2 expression (-51% compared to baseline levels, p = 0.008) and plasma HMGB1 levels (-17% compared to baseline levels, p<0.001) in healthy individuals. Half of the individuals had a reduction in ACE2 levels of at least 30%. HMGB1 levels in patients with mild COVID-19 and ARDS patients with and without COVID-19 were significantly higher compared with those of healthy individuals (+317%, p = 0.002), but they were not different between COVID-19 and non-COVID-19 ARDS. CONCLUSIONS: Liquorice intake modulates ACE2 and HMGB1 levels in healthy individuals. HMGB1 is enhanced in mild COVID-19 and in ARDS with and without COVID-19, warranting evaluation of HMGB1 as a potential treatment target and glycyrrhizin, which is an active component of liquorice root extract, as a potential treatment in COVID-19 and non-COVID-19 respiratory disease.

miR449 Protects Airway Regeneration by Controlling AURKA/HDAC6-Mediated Ciliary Disassembly.

Airway mucociliary regeneration and function are key players for airway defense and are impaired in chronic obstructive pulmonary disease (COPD). Using transcriptome analysis in COPD-derived bronchial biopsies, we observed a positive correlation between cilia-related genes and microRNA-449 (miR449). In vitro, miR449 was strongly increased during airway epithelial mucociliary differentiation. In vivo, miR449 was upregulated during recovery from chemical or infective insults. miR0449-/- mice (both alleles are deleted) showed impaired ciliated epithelial regeneration after naphthalene and Haemophilus influenzae exposure, accompanied by more intense inflammation and emphysematous manifestations of COPD. The latter occurred spontaneously in aged miR449-/- mice. We identified Aurora kinase A and its effector target HDAC6 as key mediators in miR449-regulated ciliary homeostasis and epithelial regeneration. Aurora kinase A is downregulated upon miR449 overexpression in vitro and upregulated in miR449-/- mouse lungs. Accordingly, imaging studies showed profoundly altered cilia length and morphology accompanied by reduced mucociliary clearance. Pharmacological inhibition of HDAC6 rescued cilia length and coverage in miR449-/- cells, consistent with its tubulin-deacetylating function. Altogether, our study establishes a link between miR449, ciliary dysfunction, and COPD pathogenesis.

Distinct Patterns of Blood Cytokines Beyond a Cytokine Storm Predict Mortality in COVID-19.

BACKGROUND: COVID-19 comprises several severity stages ranging from oligosymptomatic disease to multi-organ failure and fatal outcomes. The mechanisms why COVID-19 is a mild disease in some patients and progresses to a severe multi-organ and often fatal disease with respiratory failure are not known. Biomarkers that predict the course of disease are urgently needed. The aim of this study was to evaluate a large spectrum of established laboratory measurements. PATIENTS AND METHODS: Patients from the prospective PULMPOHOM and CORSAAR studies were recruited and comprised 35 patients with COVID-19, 23 with conventional pneumonia, and 28 control patients undergoing elective non-pulmonary surgery. Venous blood was used to measure the serum concentrations of 79 proteins by Luminex multiplex immunoassay technology. Distribution of biomarkers between groups and association with disease severity and outcomes were analyzed. RESULTS: The biomarker profiles between the three groups differed significantly with elevation of specific proteins specific for the respective conditions. Several biomarkers correlated significantly with disease severity and death. Uniform manifold approximation and projection (UMAP) analysis revealed a significant separation of the three disease groups and separated between survivors and deceased patients. Different models were developed to predict mortality based on the baseline measurements of several protein markers. A score combining IL-1ra, IL-8, IL-10, MCP-1, SCF and CA-9 was associated with significantly higher mortality (AUC 0.929). DISCUSSION: Several newly identified blood markers were significantly increased in patients with severe COVID-19 (AAT, EN-RAGE, myoglobin, SAP, TIMP-1, vWF, decorin) or in patients that died (IL-1ra, IL-8, IL-10, MCP-1, SCF, CA-9). The use of established assay technologies allows for rapid translation into clinical practice.

Swarm Learning for decentralized and confidential clinical machine learning.

Fast and reliable detection of patients with severe and heterogeneous illnesses is a major goal of precision medicine1,2. Patients with leukaemia can be identified using machine learning on the basis of their blood transcriptomes3. However, there is an increasing divide between what is technically possible and what is allowed, because of privacy legislation4,5. Here, to facilitate the integration of any medical data from any data owner worldwide without violating privacy laws, we introduce Swarm Learning-a decentralized machine-learning approach that unites edge computing, blockchain-based peer-to-peer networking and coordination while maintaining confidentiality without the need for a central coordinator, thereby going beyond federated learning. To illustrate the feasibility of using Swarm Learning to develop disease classifiers using distributed data, we chose four use cases of heterogeneous diseases (COVID-19, tuberculosis, leukaemia and lung pathologies). With more than 16,400 blood transcriptomes derived from 127 clinical studies with non-uniform distributions of cases and controls and substantial study biases, as well as more than 95,000 chest X-ray images, we show that Swarm Learning classifiers outperform those developed at individual sites. In addition, Swarm Learning completely fulfils local confidentiality regulations by design. We believe that this approach will notably accelerate the introduction of precision medicine.

The IL-17 receptor IL-17RE mediates polyIC-induced exacerbation of experimental allergic asthma

BACKGROUND: The interleukin 17 receptor E (IL-17RE) is specific for the epithelial cytokine interleukin-17C (IL-17C). Asthma exacerbations are frequently caused by viral infections. Polyinosinic:polycytidylic acid (pIC) mimics viral infections through binding to pattern recognition receptors (e.g. TLR-3). We and others have shown that pIC induces the expression of IL-17C in airway epithelial cells. Using different mouse models, we aimed to investigate the function of IL-17RE in the development of experimental allergic asthma and acute exacerbation thereof. METHODS: Wild-type (WT) and IL-17RE deficient (Il-17re-/-) mice were sensitized and challenged with OVA to induce allergic airway inflammation. pIC or PBS were applied intranasally when allergic airway inflammation had been established. Pulmonary expression of inflammatory mediators, numbers of inflammatory cells, and airway hyperresponsiveness (AHR) were analyzed. RESULTS: Ablation of IL-17RE did not affect the development of OVA-induced allergic airway inflammation and AHR. pIC induced inflammation independent of IL-17RE in the absence of allergic airway inflammation. Treatment of mice with pIC exacerbated pulmonary inflammation in sensitized and OVA-challenged mice in an IL-17RE-dependent manner. The pIC-induced expression of cytokines (e.g. keratinocyte-derived chemokine (KC), granulocyte-colony stimulating factor (G-CSF)) and recruitment of neutrophils were decreased in Il-17re-/- mice. pIC-exacerbated AHR was partially decreased in Il-17re-/- mice. CONCLUSIONS: Our results indicate that IL-17RE mediates virus-triggered exacerbations but does not have a function in the development of allergic lung disease.