The Potential Impact of Heparanase Activity and Endothelial Damage in COVID-19 Disease.

SARS-CoV-2 was first detected in 2019 in Wuhan, China. It has been found to be the most pathogenic virus among coronaviruses and is associated with endothelial damage resulting in respiratory failure. Determine whether heparanase and heparan sulfate fragments, biomarkers of endothelial function, can assist in the risk stratification and clinical management of critically ill COVID-19 patients admitted to the intensive care unit. We investigated 53 critically ill patients with severe COVID-19 admitted between March and April 2020 to the University Hospital RWTH Aachen. Heparanase activity and serum levels of both heparanase and heparan sulfate were measured on day one (day of diagnosis) and day three in patients with COVID-19. The patients were classified into four groups according to the severity of ARDS. When compared to baseline data (day one), heparanase activity increased and the heparan sulfate serum levels decreased with increasing severity of ARDS. The heparanase activity significantly correlated with the lactate concentration on day one (r = 0.34, p = 0.024) and on day three (r = 0.43, p = 0.006). Heparanase activity and heparan sulfate levels correlate with COVID-19 disease severity and outcome. Both biomarkers might be helpful in predicting clinical course and outcomes in COVID-19 patients.

Inhibition of Macrophage Migration Inhibitory Factor Activity Attenuates Haemorrhagic Shock-Induced Multiple Organ Dysfunction in Rats.

Objective: The aim of this study was to investigate (a) macrophage migration inhibitory factor (MIF) levels in polytrauma patients and rats after haemorrhagic shock (HS), (b) the potential of the MIF inhibitor ISO-1 to reduce multiple organ dysfunction syndrome (MODS) in acute (short-term and long-term follow-up) HS rat models and (c) whether treatment with ISO-1 attenuates NF-κB and NLRP3 activation in HS. Background: The MODS caused by an excessive systemic inflammatory response following trauma is associated with a high morbidity and mortality. MIF is a pleiotropic cytokine which can modulate the inflammatory response, however, its role in trauma is unknown. Methods: The MIF levels in plasma of polytrauma patients and serum of rats with HS were measured by ELISA. Acute HS rat models were performed to determine the influence of ISO-1 on MODS. The activation of NF-κB and NLRP3 pathways were analysed by western blot in the kidney and liver. Results: We demonstrated that (a) MIF levels are increased in polytrauma patients on arrival to the emergency room and in rats after HS, (b) HS caused organ injury and/or dysfunction and hypotension (post-resuscitation) in rats, while (c) treatment of HS-rats with ISO-1 attenuated the organ injury and dysfunction in acute HS models and (d) reduced the activation of NF-κB and NLRP3 pathways in the kidney and liver. Conclusion: Our results point to a role of MIF in the pathophysiology of trauma-induced organ injury and dysfunction and indicate that MIF inhibitors may be used as a potential therapeutic approach for MODS after trauma and/or haemorrhage.

Prognostic Value of Bioactive Adrenomedullin in Critically Ill Patients with COVID-19 in Germany: An Observational Cohort Study.

The coronavirus disease 2019 (COVID-19) pandemic has placed a significant burden on hospitals worldwide. Objective biomarkers for early risk stratification and clinical management are still lacking. The aim of this work was to determine whether bioactive adrenomedullin can assist in the risk stratification and clinical management of critically ill COVID-19 patients. Fifty-three patients with confirmed COVID-19 were included in this prospective observational cohort study between March and April 2020. Bioactive adrenomedullin (bio-ADM) plasma concentration was measured daily for seven days after admission. The prognostic value and clinical significance of bio-ADM plasma levels were evaluated for the severity of respiratory failure, the need for extracorporeal organ support and outcome (28-day mortality). Bio-ADM levels increased with the severity of acute respiratory distress syndrome (ARDS; p < 0.001) and were significantly elevated in invasively ventilated patients (p = 0.006) and patients in need of extracorporeal membrane oxygenation (p = 0.040) or renal replacement therapy (RRT; p < 0.001) compared to patients without these conditions. Non-survivors showed significantly higher bio-ADM levels than survivors (p = 0.010). Bio-ADM levels predicted 28-day mortality (C-index 0.72, 95% confidence interval 0.56-0.87, p < 0.001). Bio-ADM plasma levels correlate with disease severity, the need for extracorporeal organ assistance, and outcome, and highlight the promising value of bio-ADM in the early risk stratification and management of patients with COVID-19.

Macrophage Migration Inhibitory Factor (MIF) Plasma Concentration in Critically Ill COVID-19 Patients: A Prospective Observational Study.

Mortality in critically ill coronavirus disease 2019 (COVID-19) patients is high and pharmacological treatment strategies remain limited. Early-stage predictive biomarkers are needed to identify patients with a high risk of severe clinical courses and to stratify treatment strategies. Macrophage migration inhibitory factor (MIF) was previously described as a potential predictor for the outcome of critically ill patients and for acute respiratory distress syndrome (ARDS), a hallmark of severe COVID-19 disease. This prospective observational study evaluates the predictive potential of MIF for the clinical outcome after severe COVID-19 infection. Plasma MIF concentrations were measured in 36 mechanically ventilated COVID-19 patients over three days after intensive care unit (ICU) admission. Increased compared to decreased MIF was significantly associated with aggravated organ function and a significantly lower 28-day survival (sequential organ failure assessment (SOFA) score; 8.2 ± 4.5 to 14.3 ± 3, p = 0.009 vs. 8.9 ± 1.9 to 12 ± 2, p = 0.296; survival: 56% vs. 93%; p = 0.003). Arterial hypertension was the predominant comorbidity in 85% of patients with increasing MIF concentrations (vs. decreasing MIF: 39%; p = 0.015). Without reaching significance, more patients with decreasing MIF were able to improve their ARDS status (p = 0.142). The identified association between an early MIF response, aggravation of organ function and 28-day survival may open future perspectives for biomarker-based diagnostic approaches for ICU management of COVID-19 patients.

Ribonuclease 1 attenuates septic cardiomyopathy and cardiac apoptosis in a murine model of polymicrobial sepsis.

Septic cardiomyopathy is a life-threatening organ dysfunction caused by sepsis. Ribonuclease 1 (RNase 1) belongs to a group of host-defense peptides that specifically cleave extracellular RNA (eRNA). The activity of RNase 1 is inhibited by ribonuclease-inhibitor 1 (RNH1). However, the role of RNase 1 in septic cardiomyopathy and associated cardiac apoptosis is completely unknown. Here, we show that sepsis resulted in a significant increase in RNH1 and eRNA serum levels compared with those of healthy subjects. Treatment with RNase 1 resulted in a significant decrease of apoptosis, induced by the intrinsic pathway, and TNF expression in murine cardiomyocytes exposed to either necrotic cardiomyocytes or serum of septic patients for 16 hours. Additionally, treatment of septic mice with RNase 1 resulted in a reduction in cardiac apoptosis, TNF expression, and septic cardiomyopathy. These data demonstrate that eRNA plays a crucial role in the pathophysiology of the organ (cardiac) dysfunction in sepsis and that RNase and RNH1 may be new therapeutic targets and/or strategies to reduce the cardiac injury and dysfunction caused by sepsis.

Bruton's Tyrosine Kinase Inhibition Attenuates the Cardiac Dysfunction Caused by Cecal Ligation and Puncture in Mice.

Sepsis is one of the most prevalent diseases in the world. The development of cardiac dysfunction in sepsis results in an increase of mortality. It is known that Bruton's tyrosine kinase (BTK) plays a role in toll-like receptor signaling and NLRP3 inflammasome activation, two key components in the pathophysiology of sepsis and sepsis-associated cardiac dysfunction. In this study we investigated whether pharmacological inhibition of BTK (ibrutinib 30 mg/kg and acalabrutinib 3 mg/kg) attenuates sepsis associated cardiac dysfunction in mice. 10-week old male C57BL/6 mice underwent CLP or sham surgery. One hour after surgery mice received either vehicle (5% DMSO + 30% cyclodextrin i.v.), ibrutinib (30 mg/kg i.v.), or acalabrutinib (3 mg/kg i.v.). Mice also received antibiotics and an analgesic at 6 and 18 h. After 24 h, cardiac function was assessed by echocardiography in vivo. Cardiac tissue underwent western blot analysis to determine the activation of BTK, NLRP3 inflammasome and NF-κB pathway. Serum analysis of 33 cytokines was conducted by a multiplex assay. When compared to sham-operated animals, mice subjected to CLP demonstrated a significant reduction in ejection fraction (EF), fractional shortening (FS), and fractional area change (FAC). The cardiac tissue from CLP mice showed significant increases of BTK, NF-κB, and NLRP3 inflammasome activation. CLP animals resulted in a significant increase of serum cytokines and chemokines (TNF-α, IL-6, IFN-γ, KC, eotaxin-1, eotaxin-2, IL-10, IL-4, CXCL10, and CXCL11). Delayed administration of ibrutinib and acalabrutinib attenuated the decline of EF, FS, and FAC caused by CLP and also reduced the activation of BTK, NF-κB, and NLRP3 inflammasome. Both ibrutinib and acalabrutinib significantly suppressed the release of cytokines and chemokines. Our study revealed that delayed intravenous administration of ibrutinib or acalabrutinib attenuated the cardiac dysfunction associated with sepsis by inhibiting BTK, reducing NF-κB activation and the activation of the inflammasome. Cytokines associated with sepsis were significantly reduced by both BTK inhibitors. Acalabrutinib is found to be more potent than ibrutinib and could potentially prove to be a novel therapeutic in sepsis. Thus, the FDA-approved BTK inhibitors ibrutinib and acalabrutinib may be repurposed for the use in sepsis.