Involvement of GPR43 Receptor in Effect of Lacticaseibacillus rhamnosus on Murine Steroid Resistant Chronic Obstructive Pulmonary Disease: Relevance to Pro-Inflammatory Mediators and Oxidative Stress in Human Macrophages.

BACKGROUND: Cytokine storm and oxidative stress are present in chronic obstructive pulmonary disease (COPD). Individuals with COPD present high levels of NF-κB-associated cytokines and pro-oxidant agents as well as low levels of Nrf2-associated antioxidants. This condition creates a steroid-resistant inflammatory microenvironment. Lacticaseibacillus rhamnosus (Lr) is a known anti-cytokine in lung diseases; however, the effect of Lr on lung inflammation and oxidative stress in steroid-resistant COPD mice remains unknown. OBJECTIVE: Thus, we investigated the Lr effect on lung inflammation and oxidative stress in mice and macrophages exposed to cigarette smoke extract (CSE) and unresponsive to steroids. METHODS: Mice and macrophages received dexamethasone or GLPG-094 (a GPR43 inhibitor), and only the macrophages received butyrate (but), all treatments being given before CSE. Lung inflammation was evaluated from the leukocyte population, airway remodeling, cytokines, and NF-κB. Oxidative stress disturbance was measured from ROS, 8-isoprostane, NADPH oxidase, TBARS, SOD, catalase, HO-1, and Nrf2. RESULTS: Lr attenuated cellularity, mucus, collagen, cytokines, ROS, 8-isoprostane, NADPH oxidase, and TBARS. Otherwise, SOD, catalase, HO-1, and Nrf2 were upregulated in Lr-treated COPD mice. Anti-cytokine and antioxidant effects of butyrate also occurred in CSE-exposed macrophages. GLPG-094 rendered Lr and butyrate less effective. CONCLUSIONS: Lr attenuates lung inflammation and oxidative stress in COPD mice, suggesting the presence of a GPR43 receptor-dependent mechanism also found in macrophages.

Beneficial effects of empagliflozin and liraglutide on the cerebral microcirculation of diabetic rats.

OBJECTIVES: This study aimed to evaluate the effects of the antidiabetics liraglutide, a GLP-1 analog, and empagliflozin, an SGLT-2 inhibitor, on the brain microcirculation of diabetic rats. METHODS: Type 2 diabetes mellitus (DM) was experimentally induced in male Wistar rats by combining a high-fat diet and a low dose of streptozotocin (35 mg/kg). Liraglutide (100 µg/kg s.c.) and empagliflozin (10 mg/kg, oral) were administered for 5 weeks. Body weight was monitored periodically. Oral glucose tolerance, fasting glycemia, and blood triglycerides were evaluated after the treatments. Endothelial-leukocyte interactions in the brain microcirculation and structural capillary density were assessed. RESULTS: DM rats presented metabolic and cerebrovascular alterations. Liraglutide treatment decreased body weight and blood triglycerides of DM rats. Empagliflozin treatment improved glucose tolerance but only the combination therapy significantly reduced fasting blood glucose. Both treatments and their combination reduced leukocyte adhesion into the endothelium of brain venules. However, empagliflozin was more effective in preventing DM-induced microvascular rarefaction. CONCLUSION: These findings suggest that chronic treatment with SGLT2 inhibitors and GLP-1 receptor agonists may serve as potential therapeutic approaches to prevent microvascular complications associated with diabetes.

Long-term assessment of systemic microcirculatory function and plasma cytokines after coronavirus disease 2019 (COVID-19).

Systemic microvascular dysfunction has been shown to be present in COVID-19, and serum cytokines are known to be involved in the regulation of vascular function. We sought to evaluate systemic microvascular endothelial function, with laser doppler perfusion monitoring (LDPM), and plasma levels of cytokines after acute COVID-19. Individuals admitted to a Cardiology hospital with acute COVID-19 and followed for 12-15 months after recovery underwent noninvasive evaluation of systemic endothelium-dependent microvascular reactivity by cutaneous LDPM with local thermal hyperemia (LTH). A multiplex biometric immunoassay panel was used to assess 48 serum cytokines and chemokines. Twenty patients and 14 control volunteers were enrolled. The areas under the curves of vasodilation induced by LTH were significantly increased after recovery (P=0.009) and were not different from values obtained in healthy volunteers (P = 0.85). The peak microvascular flow during LTH did also significantly increase (P = 0.02), and was not different form values obtained in healthy volunteers (P = 0.55). Several cytokines displayed significantly reduced serum concentrations after recovery from COVID-19. In conclusion, endothelium-dependent systemic microvascular reactivity improved after recovery from COVID-19 in patients with cardiovascular diseases, in parallel with a reduction in the levels of several serum cytokines and chemokines involved in the regulation of vascular function and inflammation.

Long-term assessment of systemic microcirculatory function and plasma cytokines after coronavirus disease 2019 (COVID-19)

Abstract Systemic microvascular dysfunction has been shown to be present in COVID-19, and serum cytokines are known to be involved in the regulation of vascular function. We sought to evaluate systemic microvascular endothelial function, with laser doppler perfusion monitoring (LDPM), and plasma levels of cytokines after acute COVID-19. Individuals admitted to a Cardiology hospital with acute COVID-19 and followed for 12-15 months after recovery underwent noninvasive evaluation of systemic endothelium-dependent microvascular reactivity by cutaneous LDPM with local thermal hyperemia (LTH). A multiplex biometric immunoassay panel was used to assess 48 serum cytokines and chemokines. Twenty patients and 14 control volunteers were enrolled. The areas under the curves of vasodilation induced by LTH were significantly increased after recovery (P=0.009) and were not different from values obtained in healthy volunteers (P= 0.85). The peak microvascular flow during LTH did also significantly increase (P= 0.02), and was not different form values obtained in healthy volunteers (P= 0.55). Several cytokines displayed significantly reduced serum concentrations after recovery from COVID-19. In conclusion, endothelium-dependent systemic microvascular reactivity improved after recovery from COVID-19 in patients with cardiovascular diseases, in parallel with a reduction in the levels of several serum cytokines and chemokines involved in the regulation of vascular function and inflammation.

The Na/K-ATPase role as a signal transducer in lung inflammation.

Acute respiratory distress syndrome (ARDS) is marked by damage to the capillary endothelium and alveolar epithelium following edema formation and cell infiltration. Currently, there are no effective treatments for severe ARDS. Pathologies such as sepsis, pneumonia, fat embolism, and severe trauma may cause ARDS with respiratory failure. The primary mechanism of edema clearance is the epithelial cells' Na/K-ATPase (NKA) activity. NKA is an enzyme that maintains the electrochemical gradient and cell homeostasis by transporting Na+ and K+ ions across the cell membrane. Direct injury on alveolar cells or changes in ion transport caused by infections decreases the NKA activity, loosening tight junctions in epithelial cells and causing edema formation. In addition, NKA acts as a receptor triggering signal transduction in response to the binding of cardiac glycosides. The ouabain (a cardiac glycoside) and oleic acid induce lung injury by targeting NKA. Besides enzymatic inhibition, the NKA triggers intracellular signal transduction, fostering proinflammatory cytokines production and contributing to lung injury. Herein, we reviewed and discussed the crucial role of NKA in edema clearance, lung injury, and intracellular signaling pathway activation leading to lung inflammation, thus putting the NKA as a protagonist in lung injury pathology.

Development and validation of liquid chromatography-tandem mass spectrometry method to quantify dasatinib in plasma and its application to a pharmacokinetic study

Abstract Dasatinib, a potent oral multi-targeted kinase inhibitor against Src and Bcr-Abl, can decrease inflammatory response in sepsis. A simple and cost-effective method for determination of an effective dose dasatinib was established. This method was validated in human plasma, with the aim of reducing the number of animals used, thus, avoiding ethical problems. Dasatinib and internal standard lopinavir were extracted from 180 uL of plasma using liquid-liquid extraction with methyl tert-butil ether, followed by liquid chromatography coupled to triple quadrupole mass spectrometry in multiple reaction monitoring mode. For the pharmacokinetic study, 1 mg/kg of dasatinib was administered to mice with and without sepsis. The method was linear over the concentration range of 1-98 ng/mL for DAS in mice and human plasma, with r2>0.99 and presented intra- and interday precision within the range of 2.3 - 6.2 and 4.3 - 7.0%, respectively. Further intra- and interday accuracy was within the range of 88.2 - 105.8 and 90.6 - 101.7%, respectively. The mice with sepsis showed AUC0-t = 2076.06 h*ng/mL and Cmax =102.73 ng/mL and mice without sepsis presented AUC0-t = 2128.46 h*ng/mL. Cmax = 164.5 ng/mL. The described analytical method was successfully employed in pharmacokinetic study of DAS in mice.

Agathisflavone, a natural biflavonoid that inhibits SARS-CoV-2 replication by targeting its proteases.

Despite the fast development of vaccines, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) still circulates through variants of concern (VoC) and escape the humoral immune response. SARS-CoV-2 has provoked over 200,000 deaths/months since its emergence and only a few antiviral drugs showed clinical benefit up to this moment. Thus, chemical structures endowed with anti-SARS-CoV-2 activity are important for continuous antiviral development and natural products represent a fruitful source of substances with biological activity. In the present study, agathisflavone (AGT), a biflavonoid from Anacardium occidentale was investigated as a candidate anti-SARS-CoV-2 compound. In silico and enzymatic analysis indicated that AGT may target mainly the viral main protease (Mpro) and not the papain-like protease (PLpro) in a non-competitive way. Cell-based assays in type II pneumocytes cell lineage (Calu-3) showed that SARS-CoV-2 is more susceptible to AGT than to apigenin (APG, monomer of AGT), in a dose-dependent manner, with an EC50 of 4.23 ± 0.21 µM and CC50 of 61.3 ± 0.1 µM and with a capacity to inhibit the level of pro-inflammatory mediator tumor necrosis factor-alpha (TNF-α). These results configure AGT as an interesting chemical scaffold for the development of novel semisynthetic antivirals against SARS-CoV-2.

Fluorine Atoms on C6H5-Corrole Affect the Interaction with Mpro and PLpro Proteases of SARS-CoV-2: Molecular Docking and 2D-QSAR Approaches.

The chymotrypsin-like cysteine protease (3CLpro, also known as main protease-Mpro) and papain-like protease (PLpro) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been used as the main targets for screening potential synthetic inhibitors for posterior in vitro evaluation of the most promising compounds. In this sense, the present work reports for the first time the evaluation of the interaction between Mpro/PLpro with a series of 17 porphyrin analogues-corrole (C1), meso-aryl-corrole (C2), and 15 fluorinated-meso-aryl-corrole derivatives (C3-C17) via molecular docking calculations. The impact of fluorine atoms on meso-aryl-corrole structure was also evaluated in terms of binding affinity and physical-chemical properties by two-dimensional quantitative structure-activity relationship (2D-QSAR). The presence of phenyl moieties increased the binding capacity of corrole for both proteases and depending on the position of fluorine atoms might impact positively or negatively the binding capacity. For Mpro the para-fluorine atoms might decrease drastically the binding capacity, while for PLpro there was a certain increase in the binding affinity of fluorinated-corroles with the increase of fluorine atoms into meso-aryl-corrole structure mainly from tri-fluorinated insertions. The 2D-QSAR models indicated two separated regions of higher and lower affinity for Mpro:C1-C17 based on dual electronic parameters (σI and σR), as well as one model was obtained with a correlation between the docking score value of Mpro:C2-C17 and the corresponding 13C nuclear magnetic resonance (NMR) chemical shifts of the sp2 carbon atoms (δC-1 and δC-2) of C2-C17. Overall, the fluorinated-meso-aryl-corrole derivatives showed favorable in silico parameters as potential synthetic compounds for future in vitro assays on the inhibition of SARS-CoV-2 replication.

Proteomic Profile of Procoagulant Extracellular Vesicles Reflects Complement System Activation and Platelet Hyperreactivity of Patients with Severe COVID-19.

Background: Extracellular vesicles (EVs) are a valuable source of biomarkers and display the pathophysiological status of various diseases. In COVID-19, EVs have been explored in several studies for their ability to reflect molecular changes caused by SARS-CoV-2. Here we provide insights into the roles of EVs in pathological processes associated with the progression and severity of COVID-19. Methods: In this study, we used a label-free shotgun proteomic approach to identify and quantify alterations in EV protein abundance in severe COVID-19 patients. We isolated plasma extracellular vesicles from healthy donors and patients with severe COVID-19 by size exclusion chromatography (SEC). Then, flow cytometry was performed to assess the origin of EVs and to investigate the presence of circulating procoagulant EVs in COVID-19 patients. A total protein extraction was performed, and samples were analyzed by nLC-MS/MS in a Q-Exactive HF-X. Finally, computational analysis was applied to signify biological processes related to disease pathogenesis. Results: We report significant changes in the proteome of EVs from patients with severe COVID-19. Flow cytometry experiments indicated an increase in total circulating EVs and with tissue factor (TF) dependent procoagulant activity. Differentially expressed proteins in the disease groups were associated with complement and coagulation cascades, platelet degranulation, and acute inflammatory response. Conclusions: The proteomic data reinforce the changes in the proteome of extracellular vesicles from patients infected with SARS-CoV-2 and suggest a role for EVs in severe COVID-19.

Commercially Available Flavonols Are Better SARS-CoV-2 Inhibitors than Isoflavone and Flavones.

Despite the fast development of vaccines, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is still circulating and generating variants of concern (VoC) that escape the humoral immune response. In this context, the search for anti-SARS-CoV-2 compounds is still essential. A class of natural polyphenols known as flavonoids, frequently available in fruits and vegetables, is widely explored in the treatment of different diseases and used as a scaffold for the design of novel drugs. Therefore, herein we evaluate seven flavonoids divided into three subclasses, isoflavone (genistein), flavone (apigenin and luteolin) and flavonol (fisetin, kaempferol, myricetin, and quercetin), for COVID-19 treatment using cell-based assays and in silico calculations validated with experimental enzymatic data. The flavonols were better SARS-CoV-2 inhibitors than isoflavone and flavones. The increasing number of hydroxyl groups in ring B of the flavonols kaempferol, quercetin, and myricetin decreased the 50% effective concentration (EC50) value due to their impact on the orientation of the compounds inside the target. Myricetin and fisetin appear to be preferred candidates; they are both anti-inflammatory (decreasing TNF-α levels) and inhibit SARS-CoV-2 mainly by targeting the processability of the main protease (Mpro) in a non-competitive manner, with a potency comparable to the repurposed drug atazanavir. However, fisetin and myricetin might also be considered hits that are amenable to synthetic modification to improve their anti-SARS-CoV-2 profile by inhibiting not only Mpro, but also the 3'-5' exonuclease (ExoN).

Clinical features, electroencephalogram, and biomarkers in pediatric sepsis-associated encephalopathy.

To date, no specific diagnostic criteria for sepsis-associated encephalopathy (SAE) have been established. We studied 33 pediatric patients with sepsis prospectively and evaluated the level of consciousness, the presence of delirium, electroencephalographic (EEG) findings, and plasma levels of neuron-specific enolase and S100-calcium-binding protein-B. A presumptive diagnosis of SAE was primarily considered in the presence of a decreased level of consciousness and/or delirium (clinical criteria), but specific EEG abnormalities were also considered (EEG criteria). The time course of the biomarkers was compared between groups with and without clinical or EEG criteria. The Functional Status Scale (FSS) was assessed at admission, discharge, and 3-6 months post-discharge. Clinical criteria were identified in 75.8% of patients, EEG criteria in 26.9%, both in 23.1%, and none in 23.1%. Biomarkers did not differ between groups. Three patients had an abnormal FSS at discharge, but no one on follow-up. A definitive diagnostic pattern for SAE remained unclear. Clinical criteria should be the basis for diagnosis, but sedation may be a significant confounder, also affecting EEG interpretation. The role of biomarkers requires a better definition. The diagnosis of SAE in pediatric patients remains a major challenge. New consensual diagnostic definitions and mainly prognostic studies are needed.

Mouse Model of Oleic Acid-Induced Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome (ARDS) is a significant threat to critically ill patients with a high fatality rate. Pollutant exposure, cigarette smoke, infectious agents, and fatty acids can induce ARDS. Animal models can mimic the complex pathomechanism of the ARDS. However, each of them has limitations. Notably, oleic acid (OA) is increased in critically ill patients with harmful effects on the lung. OA can induce lung injury by emboli, disrupting tissue, altering pH, and impairing edema clearance. OA-induced lung injury model resembles various features of ARDS with endothelial injury, increased alveolar permeability, inflammation, membrane hyaline formation, and cell death. Herein, induction of lung injury is described by injecting OA (in salt form) directly into the lung and intravenously in a mouse since it is the physiological form of OA at pH 7. Thus, the injection of OA in the salt form is a helpful animal model to study lung injury/ARDS without causing emboli or altering the pH, thereby getting close to what is happening in critically ill patients.

SARS-CoV-2 Infection and Possible Neonatal Neurological Outcomes: A Literature Review.

The virus responsible for COVID-19 is designated "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2), a highly transmissible and pathogenic coronavirus. Although people of all ages are susceptible to SARS-CoV-2 infection, clinical manifestations may vary with age. The response of neonates to SARS-CoV-2 infection or exposure differs from that of children and adults. Encephalitis due to viral infections in the central nervous system (CNS) and childhood multisystem inflammatory syndrome (MIS-C) are some of the possible neonatal consequences of SARS-CoV-2 infection. This review aims to verify possible neonatal neurological outcomes after SARS-CoV-2 infection. Overall, the cellular and molecular basis of the neurological sequelae of SARS-CoV-2 in neonates remains unclear, and attempts to elucidate the pathophysiology of COVID-19 involve a comparison with the mechanism of other viral diseases. There are a considerable number of case reports in the literature exploring neurological outcomes in the neonatal period. In this review, we present possible effects of SARS-CoV-2 in neonates, emphasizing the importance of monitoring this group. The mechanisms of SARS-CoV-2 entry into the CNS have not yet been fully elucidated, and the potential severity of SARS-CoV-2 infection in neonates, as well as the possible short- and long-term neurological sequelae, remain unclear.

6-Shogaol Exerts a Neuroprotective Factor in Offspring after Maternal Immune Activation in Rats.

6-Shogaol is one of the main active phenolic components of ginger and has neuroprotective effects by protecting brain against the oxidative stress and regulate the levels of neurotrophic factors. The objective of the present study was to verify the effect of 6-shogaol on neurochemical parameters in offspring after maternal immune activation by lipopolysaccharide (LPS) in rats. Twelve pregnant Wistar rats received 100 µg/kg of LPS or saline solution on the gestational day 9.5. Male offspring participated in the study and from the postnatal days (PND) 30 and 55, respectively, they were supplemented with 6-shogaol or saline solution, by gavage at a dose of 10 mg/kg/day, orally for 5 days. In PND 37 and 62, analysis of kinase signaling regulated by extracellular signal 1/2 (ERK 1/2), levels of neurotrophic factor derived from the brain (BDNF), and neuron-specific enolase (NSE), lipid and protein oxidative damage was evaluated by 4-hydroxy-2-nonenal (HNE) and 3-nitrotyrosine (3-NT), respectively, and myeloperoxidase (MPO) activity was performed in the hippocampus. Prenatal exposure to LPS significantly decreased ERK and BDNF levels in PND 37 and 62, increased NSE levels and lipid damage in rats in PND 37, and increased 3-NT level in rats in PND 62. With treatment using 6-shogaol, an increase in ERK and BDNF levels was identified in PND 37 and 62 and a reduction in HNE and MPO activity in rats in PND 37 and 62, respectively. 6-Shogaol positively increased markers of neuronal growth, plasticity and synaptic activity and reduced oxidative damage in the hippocampus in an animal model of autism by maternal immune activation.

Immunomodulatory and Anti-fibrotic Effects Following the Infusion of Umbilical Cord Mesenchymal Stromal Cells in a Critically Ill Patient With COVID-19 Presenting Lung Fibrosis: A Case Report.

Background: The patients with coronavirus disease 2019 (COVID-19) associated with severe acute respiratory distress syndrome (ARDS) may require prolonged mechanical ventilation which often results in lung fibrosis, thus worsening the prognosis and increasing fatality rates. A mesenchymal stromal cell (MSC) therapy may decrease lung inflammation and accelerate recovery in COVID-19. In this context, some studies have reported the effects of MSC therapy for patients not requiring invasive ventilation or during the first hours of tracheal intubation. However, this is the first case report presenting the reduction of not only lung inflammation but also lung fibrosis in a critically ill long-term mechanically ventilated patient with COVID-19. Case Presentation: This is a case report of a 30-year-old male patient with COVID-19 under invasive mechanical ventilation for 14 days in the intensive care unit (ICU), who presented progressive clinical deterioration associated with lung fibrosis. The symptoms onset was 35 days before MSC therapy. The patient was treated with allogenic human umbilical-cord derived MSCs [5 × 107 (2 doses 2 days interval)]. No serious adverse events were observed during and after MSC administration. After MSC therapy, PaO2/FiO2 ratio increased, the need for vasoactive drugs reduced, chest CT scan imaging, which initially showed signs of bilateral and peripheral ground-glass, as well as consolidation and fibrosis, improved, and the systemic mediators associated with inflammation decreased. Modulation of the different cell populations in peripheral blood was also observed, such as a reduction in inflammatory monocytes and an increase in the frequency of patrolling monocytes, CD4+ lymphocytes, and type 2 classical dendritic cells (cDC2). The patient was discharged 13 days after the cell therapy. Conclusions: Mesenchymal stromal cell therapy may be a promising option in critically ill patients with COVID-19 presenting both severe lung inflammation and fibrosis. Further clinical trials could better assess the efficacy of MSC therapy in critically ill patients with COVID-19 with lung fibrosis associated with long-term mechanical ventilation.

PMA treatment fosters rat retinal ganglion cell survival via TNF signaling.

An insult can trigger a protective response or even cell death depending on different factors that include the duration and magnitude of the event and the ability of the cell to activate protective intracellular signals, including inflammatory cytokines. Our previous work showed that the treatment of Lister Hooded rat retinal cell cultures with 50 ng/mL phorbol 12-myristate 13-acetate (PMA), a protein kinase C activator, increases the survival of retinal ganglion cells (RGCs) kept in culture for 48 h after axotomy. Here we aim to analyze how PMA modulates the levels of TNF-α and IL-1ß (both key inflammatory mediators) and the impact of this modulation on RGCs survival. We hypothesize that the increase in RGCs survival mediated by PMA treatment depends upon modulation of the levels of IL-1ß and TNF-α. The effect of PMA treatment was assayed on cell viability, caspase 3 activation, TNF-α and IL-1ß release and TNF receptor type I (TNFRI) and TNF receptor type II (TNFRII) levels. PMA treatment increases IL-1ß and TNF-α levels in 15 min in culture and increases the release of both cytokines after 30 min and 24 h, respectively. Both IL-1ß and TNF-α levels decrease after 48 h of PMA treatment. PMA treatment also induces an increase in TNFRII levels while decreasing TNFRI after 24 h. PMA also inhibited caspase-3 activation, and decreased ROS production and EthD-1/calcein ratio in retinal cell cultures leading to an increase in cell viability. The neutralization of IL-1ß (anti-IL1ß 0,1ng/mL), the neutralization of TNF-α (anti-TNF-α 0,1ng/mL) and the TNF-α inhibition using a recombinant soluble TNFRII abolished PMA effect on RGCs survival. These data suggest that PMA treatment induces IL1ß and TNF-α release and modulation of TNFRI/TNFRII expression promoting RGCs survival after axotomy.

Glucagon Reduces Neutrophil Migration and Increases Susceptibility to Sepsis in Diabetic Mice.

Sepsis is one of the most common comorbidities observed in diabetic patients, associated with a deficient innate immune response. Recently, we have shown that glucagon possesses anti-inflammatory properties. In this study, we investigated if hyperglucagonemia triggered by diabetes might reduce the migration of neutrophils, increasing sepsis susceptibility. 21 days after diabetes induction by intravenous injection of alloxan, we induced moderate sepsis in Swiss-Webster mice through cecum ligation and puncture (CLP). The glucagon receptor (GcgR) antagonist des-his1-[Glu9]-glucagon amide was injected intraperitoneally 24h and 1h before CLP. We also tested the effect of glucagon on CXCL1/KC-induced neutrophil migration to the peritoneal cavity in mice. Neutrophil chemotaxis in vitro was tested using transwell plates, and the expression of total PKA and phospho-PKA was evaluated by western blot. GcgR antagonist restored neutrophil migration, reduced CFU numbers in the peritoneal cavity and improved survival rate of diabetic mice after CLP procedure, however, the treatment did no alter hyperglycemia, CXCL1/KC plasma levels and blood neutrophilia. In addition, glucagon inhibited CXCL1/KC-induced neutrophil migration to the peritoneal cavity of non-diabetic mice. Glucagon also decreased the chemotaxis of neutrophils triggered by CXCL1/KC, PAF, or fMLP in vitro. The inhibitory action of glucagon occurred in parallel with the reduction of CXCL1/KC-induced actin polymerization in neutrophils in vitro, but not CD11a and CD11b translocation to cell surface. The suppressor effect of glucagon on CXCL1/KC-induced neutrophil chemotaxis in vitro was reversed by pre-treatment with GcgR antagonist and adenylyl cyclase or PKA inhibitors. Glucagon also increased PKA phosphorylation directly in neutrophils in vitro. Furthermore, glucagon impaired zymosan-A-induced ROS production by neutrophils in vitro. Human neutrophil chemotaxis and adherence to endothelial cells in vitro were inhibited by glucagon treatment. According to our results, this inhibition was independent of CD11a and CD11b translocation to neutrophil surface or neutrophil release of CXCL8/IL-8. Altogether, our results suggest that glucagon may be involved in the reduction of neutrophil migration and increased susceptibility to sepsis in diabetic mice. This work collaborates with better understanding of the increased susceptibility and worsening of sepsis in diabetics, which can contribute to the development of new effective therapeutic strategies for diabetic septic patients.

Should COVID-19 be branded to viral thrombotic fever?

Coronaviruses can cause a diverse array of clinical manifestations, from fever with symptoms of the common cold to highly lethal severe acute respiratory syndrome (SARS) and middle east respiratory syndrome (MERS). SARS-CoV-2, the coronavirus discovered in Hubei province, China, at the end of 2019, became known worldwide for causing coronavirus disease 2019 (COVID-19). Over one year's time period, the scientific community has produced a large bulk of knowledge about this disease and countless reports about its immune-pathological aspects. This knowledge, including data obtained in postmortem studies, points unequivocally to a hypercoagulability state. However, the name COVID-19 tells us very little about the true meaning of the disease. Our proposal is more comprehensive; it intends to frame COVID-19 in more clinical terminology, making an analogy to viral haemorrhagic fever (VHF). Thus, we found irrefutable evidence in the current literature that COVID-19 is the first viral disease that can be branded as a viral thrombotic fever. This manuscript points out that SARS-CoV-2 goes far beyond pneumonia or SARS. COVID-19 infections promote remarkable interactions among the endothelium, coagulation, and immune response, building up a background capable of promoting a "thrombotic storm," much more than a "cytokine storm." The importance of a viral protease called main protease (Mpro) is highlighted as a critical component for its replication in the host cell. A deeper analysis of this protease and its importance on the coagulation system is also discussed for the first time, mainly because of its similarity with the thrombin and factor Xa molecules, as recently pointed out by structural comparison crystallographic structures.