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1.
Crit Care Explor ; 2(9): e0202, 2020 Sep.
Article in English | MEDLINE | ID: covidwho-1795075

ABSTRACT

OBJECTIVES: Patients with coronavirus disease 2019 acute respiratory distress syndrome appear to present with at least two distinct phenotypes: severe hypoxemia with relatively well-preserved lung compliance and lung gas volumes (type 1) and a more conventional acute respiratory distress syndrome phenotype, displaying the typical characteristics of the "baby lung" (type 2). We aimed to test plausible hypotheses regarding the pathophysiologic mechanisms underlying coronavirus disease 2019 acute respiratory distress syndrome and to evaluate the resulting implications for ventilatory management. DESIGN: We adapted a high-fidelity computational simulator, previously validated in several studies of acute respiratory distress syndrome, to: 1) develop quantitative insights into the key pathophysiologic differences between the coronavirus disease 2019 acute respiratory distress syndrome and the conventional acute respiratory distress syndrome and 2) assess the impact of different positive end-expiratory pressure, Fio2, and tidal volume settings. SETTING: Interdisciplinary Collaboration in Systems Medicine Research Network. SUBJECTS: The simulator was calibrated to represent coronavirus disease 2019 acute respiratory distress syndrome patients with both normal and elevated body mass indices undergoing invasive mechanical ventilation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: An acute respiratory distress syndrome model implementing disruption of hypoxic pulmonary vasoconstriction and vasodilation leading to hyperperfusion of collapsed lung regions failed to replicate clinical data on type 1 coronavirus disease 2019 acute respiratory distress syndrome patients. Adding mechanisms to reflect disruption of alveolar gas-exchange due to the effects of pneumonitis and heightened vascular resistance due to the emergence of microthrombi produced levels of ventilation perfusion mismatch and hypoxemia consistent with data from type 1 coronavirus disease 2019 acute respiratory distress syndrome patients, while preserving close-to-normal lung compliance and gas volumes. Atypical responses to positive end-expiratory pressure increments between 5 and 15 cm H2O were observed for this type 1 coronavirus disease 2019 acute respiratory distress syndrome model across a range of measures: increasing positive end-expiratory pressure resulted in reduced lung compliance and no improvement in oxygenation, whereas mechanical power, driving pressure, and plateau pressure all increased. Fio2 settings based on acute respiratory distress syndrome network protocols at different positive end-expiratory pressure levels were insufficient to achieve adequate oxygenation. Incrementing tidal volumes from 5 to 10 mL/kg produced similar increases in multiple indicators of ventilator-induced lung injury in the type 1 coronavirus disease 2019 acute respiratory distress syndrome model to those seen in a conventional acute respiratory distress syndrome model. CONCLUSIONS: Our model suggests that use of standard positive end-expiratory pressure/Fio2 tables, higher positive end-expiratory pressure strategies, and higher tidal volumes may all be potentially deleterious in type 1 coronavirus disease 2019 acute respiratory distress syndrome patients, and that a highly personalized approach to treatment is advisable.

2.
Clin Infect Dis ; 74(3): 479-489, 2022 02 11.
Article in English | MEDLINE | ID: covidwho-1684541

ABSTRACT

BACKGROUND: Increased inflammation has been well defined in coronavirus disease 2019 (COVID-19), while definitive pathways driving severe forms of this disease remain uncertain. Neutrophils are known to contribute to immunopathology in infections, inflammatory diseases, and acute respiratory distress syndrome, a primary cause of morbidity and mortality in COVID-19. Changes in neutrophil function in COVID-19 may give insight into disease pathogenesis and identify therapeutic targets. METHODS: Blood was obtained serially from critically ill COVID-19 patients for 11 days. Neutrophil extracellular trap formation (NETosis), oxidative burst, phagocytosis, and cytokine levels were assessed. Lung tissue was obtained immediately postmortem for immunostaining. PubMed searches for neutrophils, lung, and COVID-19 yielded 10 peer-reviewed research articles in English. RESULTS: Elevations in neutrophil-associated cytokines interleukin 8 (IL-8) and interleukin 6, and general inflammatory cytokines IFN-inducible protien-19, granulocyte macrophage colony-stimulating factor (GM-CSF), interleukin 1ß, interleukin 10, and tumor necrosis factor, were identified both at first measurement and across hospitalization (P < .0001). COVID-19 neutrophils had exaggerated oxidative burst (P < .0001), NETosis (P < .0001), and phagocytosis (P < .0001) relative to controls. Increased NETosis correlated with leukocytosis and neutrophilia, and neutrophils and NETs were identified within airways and alveoli in lung parenchyma of 40% of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected lungs available for examination (2 of 5). While elevations in IL-8 and absolute neutrophil count correlated with disease severity, plasma IL-8 levels alone correlated with death. CONCLUSIONS: Literature to date demonstrates compelling evidence of increased neutrophils in the circulation and lungs of COVID-19 patients. Importantly, neutrophil quantity and activation correlates with severity of disease. Similarly, our data show that circulating neutrophils in COVID-19 exhibit an activated phenotype with enhanced NETosis and oxidative burst.


Subject(s)
COVID-19 , Extracellular Traps , Critical Illness , Humans , Neutrophil Activation , Neutrophils , Phenotype , SARS-CoV-2
3.
Curr Med Imaging ; 17(11): 1324-1329, 2021.
Article in English | MEDLINE | ID: covidwho-1574892

ABSTRACT

BACKGROUND AND AIMS: Coronavirus Disease 2019 (COVID-19) pandemic has become a global health issue. This study aimed to explore the clinical characteristics and CT imaging features of patients with COVID-19 on admission. METHODS: Consecutive patients with laboratory-confirmed COVID-19 were retrospectively recruited to this study from January 2020 to March 2020. According to the disease severity status on admission, patients were divided into two groups, the common group, and the severe group. RESULTS: Forty-four patients (F/M 20/24) who were COVID-19 positive were enrolled in this study. The most common onset symptom was fever (90.9%), followed by cough (43.2%). As for the laboratory tests, common findings included increased C reactive protein (47.7%) and erythrocyte sedimentation rate (43.2%) and decreased lymphocyte (34.1%). The frequency of decreased lymphocyte count and increased lactate dehydrogenasewas higher in the severe group (n=14) than in the common group (n=30). About 86% of patients showed typical imaging findings of COVID-19 infection, including ground-glass opacity with ill-defined margins, air bronchogram, interlobular septal thickening, and consolidation. Lesions were mainly located in the peripheral and subpleural regions with diffused distribution and multiple lung lobes were found to be affected. CONCLUSION: Fever and cough were the most common onset symptoms of COVID-19. Increased C reactive protein and erythrocyte sedimentation rate were the most common laboratory findings. Typical signs of chest CT imaging of COVID-19 included ground-glass opacity with ill-defined margins, air bronchogram, interlobular septal thickening, and consolidation.


Subject(s)
COVID-19 , Humans , Retrospective Studies , SARS-CoV-2
4.
Clin Infect Dis ; 73(11): e4154-e4165, 2021 12 06.
Article in English | MEDLINE | ID: covidwho-1559099

ABSTRACT

BACKGROUND: Children and older adults with coronavirus disease 2019 (COVID-19) display a distinct spectrum of disease severity yet the risk factors aren't well understood. We sought to examine the expression pattern of angiotensin-converting enzyme 2 (ACE2), the cell-entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and the role of lung progenitor cells in children and older patients. METHODS: We retrospectively analyzed clinical features in a cohort of 299 patients with COVID-19. The expression and distribution of ACE2 and lung progenitor cells were systematically examined using a combination of public single-cell RNA-seq data sets, lung biopsies, and ex vivo infection of lung tissues with SARS-CoV-2 pseudovirus in children and older adults. We also followed up patients who had recovered from COVID-19. RESULTS: Compared with children, older patients (>50 years.) were more likely to develop into serious pneumonia with reduced lymphocytes and aberrant inflammatory response (P = .001). The expression level of ACE2 and lung progenitor cell markers were generally decreased in older patients. Notably, ACE2 positive cells were mainly distributed in the alveolar region, including SFTPC positive cells, but rarely in airway regions in the older adults (P < .01). The follow-up of discharged patients revealed a prolonged recovery from pneumonia in the older (P < .025). CONCLUSIONS: Compared to children, ACE2 positive cells are generally decreased in older adults and mainly presented in the lower pulmonary tract. The lung progenitor cells are also decreased. These risk factors may impact disease severity and recovery from pneumonia caused by SARS-Cov-2 infection in older patients.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19 , Stem Cells , Aged , Child , Humans , Lung/cytology , Middle Aged , RNA-Seq , Retrospective Studies , Severity of Illness Index
5.
Angiogenesis ; 24(3): 677-693, 2021 08.
Article in English | MEDLINE | ID: covidwho-1549443

ABSTRACT

Endothelial barrier disruption and vascular leak importantly contribute to organ dysfunction and mortality during inflammatory conditions like sepsis and acute respiratory distress syndrome. We identified the kinase Arg/Abl2 as a mediator of endothelial barrier disruption, but the role of Arg in endothelial monolayer regulation and its relevance in vivo remain poorly understood. Here we show that depletion of Arg in endothelial cells results in the activation of both RhoA and Rac1, increased cell spreading and elongation, redistribution of integrin-dependent cell-matrix adhesions to the cell periphery, and improved adhesion to the extracellular matrix. We further show that Arg is activated in the endothelium during inflammation, both in murine lungs exposed to barrier-disruptive agents, and in pulmonary microvessels of septic patients. Importantly, Arg-depleted endothelial cells were less sensitive to barrier-disruptive agents. Despite the formation of F-actin stress fibers and myosin light chain phosphorylation, Arg depletion diminished adherens junction disruption and intercellular gap formation, by reducing the disassembly of cell-matrix adhesions and cell retraction. In vivo, genetic deletion of Arg diminished vascular leak in the skin and lungs, in the presence of a normal immune response. Together, our data indicate that Arg is a central and non-redundant regulator of endothelial barrier integrity, which contributes to cell retraction and gap formation by increasing the dynamics of adherens junctions and cell-matrix adhesions in a Rho GTPase-dependent fashion. Therapeutic inhibition of Arg may provide a suitable strategy for the treatment of a variety of clinical conditions characterized by vascular leak.


Subject(s)
Extracellular Matrix/metabolism , Gap Junctions/enzymology , Human Umbilical Vein Endothelial Cells/enzymology , Protein-Tyrosine Kinases/metabolism , Pulmonary Alveoli/enzymology , Animals , Cell Adhesion/genetics , Enzyme Activation , Extracellular Matrix/genetics , Gap Junctions/genetics , Humans , Inflammation/enzymology , Inflammation/genetics , Mice , Mice, Knockout , Protein-Tyrosine Kinases/genetics
6.
Toxins (Basel) ; 12(4)2020 04 02.
Article in English | MEDLINE | ID: covidwho-1453289

ABSTRACT

Bacterial toxins play a key role in the pathogenesis of lung disease. Based on their structural and functional properties, they employ various strategies to modulate lung barrier function and to impair host defense in order to promote infection. Although in general, these toxins target common cellular signaling pathways and host compartments, toxin- and cell-specific effects have also been reported. Toxins can affect resident pulmonary cells involved in alveolar fluid clearance (AFC) and barrier function through impairing vectorial Na+ transport and through cytoskeletal collapse, as such, destroying cell-cell adhesions. The resulting loss of alveolar-capillary barrier integrity and fluid clearance capacity will induce capillary leak and foster edema formation, which will in turn impair gas exchange and endanger the survival of the host. Toxins modulate or neutralize protective host cell mechanisms of both the innate and adaptive immunity response during chronic infection. In particular, toxins can either recruit or kill central players of the lung's innate immune responses to pathogenic attacks, i.e., alveolar macrophages (AMs) and neutrophils. Pulmonary disorders resulting from these toxin actions include, e.g., acute lung injury (ALI), the acute respiratory syndrome (ARDS), and severe pneumonia. When acute infection converts to persistence, i.e., colonization and chronic infection, lung diseases, such as bronchitis, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF) can arise. The aim of this review is to discuss the impact of bacterial toxins in the lungs and the resulting outcomes for pathogenesis, their roles in promoting bacterial dissemination, and bacterial survival in disease progression.


Subject(s)
Bacteria/pathogenicity , Bacterial Infections/microbiology , Bacterial Toxins/metabolism , Lung/microbiology , Respiratory Tract Infections/microbiology , Adaptive Immunity , Animals , Bacteria/immunology , Bacteria/metabolism , Bacterial Infections/immunology , Bacterial Infections/metabolism , Bacterial Infections/pathology , Disease Progression , Host-Pathogen Interactions , Humans , Immunity, Innate , Lung/immunology , Lung/metabolism , Lung/pathology , Respiratory Tract Infections/immunology , Respiratory Tract Infections/metabolism , Respiratory Tract Infections/pathology , Signal Transduction
7.
Intensive Care Med Exp ; 8(1): 8, 2020 Feb 05.
Article in English | MEDLINE | ID: covidwho-1453065

ABSTRACT

BACKGROUND: Human mesenchymal stem/stromal cells (hMSCs) represent a promising therapeutic strategy for ventilator-induced lung injury (VILI) and acute respiratory distress syndrome. Translational challenges include restoring hMSC efficacy following cryopreservation, developing effective xenogeneic-free (XF) hMSCs and establishing true therapeutic potential at a clinically relevant time point of administration. We wished to determine whether cytokine pre-activation of cryopreserved, bone marrow-derived XF-hMSCs would enhance their capacity to facilitate injury resolution following VILI and elucidate mechanisms of action. METHODS: Initially, in vitro studies examined the potential for the secretome from cytokine pre-activated XF-hMSCs to attenuate pulmonary epithelial injury induced by cyclic mechanical stretch. Later, anaesthetised rats underwent VILI and, 6 h following injury, were randomized to receive 1 × 107 XF-hMSC/kg that were (i) naive fresh, (ii) naive cryopreserved, (iii) cytokine pre-activated fresh or (iv) cytokine pre-activated cryopreserved, while control animals received (v) vehicle. The extent of injury resolution was measured at 24 h after injury. Finally, the role of keratinocyte growth factor (KGF) in mediating the effect of pre-activated XF-hMSCs was determined in a pulmonary epithelial wound repair model. RESULTS: Pre-activation enhanced the capacity of the XF-hMSC secretome to decrease stretch-induced pulmonary epithelial inflammation and injury. Both pre-activated fresh and cryopreserved XF-hMSCs enhanced resolution of injury following VILI, restoring oxygenation, improving lung compliance, reducing lung leak and improving resolution of lung structural injury. Finally, the secretome of pre-activated XF-hMSCs enhanced epithelial wound repair, in part via a KGF-dependent mechanism. CONCLUSIONS: Cytokine pre-activation enhanced the capacity of cryopreserved, XF-hMSCs to promote injury resolution following VILI, potentially via a KGF-dependent mechanism.

8.
Surg Today ; 51(3): 447-451, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-1453756

ABSTRACT

Accumulation of experience and advances in techniques and instruments have enabled surgeons to perform video-assisted thoracic surgery (VATS) safely for sublobar resection, including segmentectomy and wedge resection. A key to successful VATS sublobar resection is to have adequate resection margins and the appropriate use of articulated surgical staplers is essential for this purpose. The SigniaTM stapling system (Covidien Japan, Tokyo) has been used extensively in the fields of thoracic surgery. Its features include high maneuverability with fully powered articulation, rotation, clamping, and firing, which the surgeon can control with one hand. We introduce the "sliding technique" using the SigniaTM system, which allows for adjustment of the resection lines of the pulmonary parenchyma to optimize safe surgical margins with minimal stapler movement, and without repetitively moving the stapler in and out of the pleural cavity, during VATS sublobar resection.


Subject(s)
Lung Neoplasms/surgery , Lung/surgery , Margins of Excision , Pneumonectomy/instrumentation , Pneumonectomy/methods , Surgical Staplers , Surgical Stapling/instrumentation , Surgical Stapling/methods , Thoracic Surgery, Video-Assisted/instrumentation , Thoracic Surgery, Video-Assisted/methods , Humans , Safety
9.
Antimicrob Agents Chemother ; 65(9): e0060221, 2021 08 17.
Article in English | MEDLINE | ID: covidwho-1434879

ABSTRACT

Remdesivir (RDV; GS-5734, Veklury), the first FDA-approved antiviral to treat COVID-19, is a single-diastereomer monophosphoramidate prodrug of an adenosine analogue. RDV is taken up in the target cells and metabolized in multiple steps to form the active nucleoside triphosphate (TP) (GS-443902), which, in turn, acts as a potent and selective inhibitor of multiple viral RNA polymerases. In this report, we profiled the key enzymes involved in the RDV metabolic pathway with multiple parallel approaches: (i) bioinformatic analysis of nucleoside/nucleotide metabolic enzyme mRNA expression using public human tissue and lung single-cell bulk mRNA sequence (RNA-seq) data sets, (ii) protein and mRNA quantification of enzymes in human lung tissue and primary lung cells, (iii) biochemical studies on the catalytic rate of key enzymes, (iv) effects of specific enzyme inhibitors on the GS-443902 formation, and (v) the effects of these inhibitors on RDV antiviral activity against SARS-CoV-2 in cell culture. Our data collectively demonstrated that carboxylesterase 1 (CES1) and cathepsin A (CatA) are enzymes involved in hydrolyzing RDV to its alanine intermediate MetX, which is further hydrolyzed to the monophosphate form by histidine triad nucleotide-binding protein 1 (HINT1). The monophosphate is then consecutively phosphorylated to diphosphate and triphosphate by cellular phosphotransferases. Our data support the hypothesis that the unique properties of RDV prodrug not only allow lung-specific accumulation critical for the treatment of respiratory viral infection such as COVID-19 but also enable efficient intracellular metabolism of RDV and its MetX to monophosphate and successive phosphorylation to form the active TP in disease-relevant cells.


Subject(s)
COVID-19 , SARS-CoV-2 , Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/pharmacology , COVID-19/drug therapy , Humans , Lung , Nerve Tissue Proteins
10.
Immunology ; 163(3): 239-249, 2021 07.
Article in English | MEDLINE | ID: covidwho-1434725

ABSTRACT

Communication between stromal and immune cells is essential to maintain tissue homeostasis, mount an effective immune response and promote tissue repair. This 'crosstalk' occurs in both the steady state and following a variety of insults, for example, in response to local injury, at sites of infection or cancer. What do we mean by crosstalk between cells? Reciprocal activation and/or regulation occurs between immune and stromal cells, by direct cell contact and indirect mechanisms, including the release of soluble cytokines. Moving beyond cell-to-cell contact, this review investigates the complexity of 'cross-space' cellular communication. We highlight different examples of cellular communication by a variety of lung stromal and immune cells following tissue insults. This review examines how the 'geography of the lung microenvironment' is altered in various disease states; more specifically, we investigate how this influences lung epithelial cells and fibroblasts via their communication with immune cells and each other.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Epithelial Cells/immunology , Fibroblasts/immunology , Lung/pathology , Stromal Cells/immunology , Animals , Cell Communication , Cellular Microenvironment , Humans , Immunity, Cellular
11.
AJR Am J Roentgenol ; 214(6): 1287-1294, 2020 06.
Article in English | MEDLINE | ID: covidwho-1408325

ABSTRACT

OBJECTIVE. The purpose of this study was to investigate 62 subjects in Wuhan, China, with laboratory-confirmed coronavirus disease (COVID-19) pneumonia and describe the CT features of this epidemic disease. MATERIALS AND METHODS. A retrospective study of 62 consecutive patients with laboratory-confirmed COVID-19 pneumonia was performed. CT images and clinical data were reviewed. Two thoracic radiologists evaluated the distribution and CT signs of the lesions and also scored the extent of involvement of the CT signs. The Mann-Whitney U test was used to compare lesion distribution and CT scores. The chi-square test was used to compare the CT signs of early-phase versus advanced-phase COVID-19 pneumonia. RESULTS. A total of 62 patients (39 men and 23 women; mean [± SD] age, 52.8 ± 12.2 years; range, 30-77 years) with COVID-19 pneumonia were evaluated. Twenty-four of 30 patients who underwent routine blood tests (80.0%) had a decreased lymphocyte count. Of 27 patients who had their erythrocyte sedimentation rate and high-sensitivity C-reactive protein level assessed, 18 (66.7%) had an increased erythrocyte sedimentation rate, and all 27 (100.0%) had an elevated high-sensitivity C-reactive protein level. Multiple lesions were seen on the initial CT scan of 52 of 62 patients (83.9%). Forty-eight of 62 patients (77.4%) had predominantly peripheral distribution of lesions. The mean CT score for the upper zone (3.0 ± 3.4) was significantly lower than that for the middle (4.5 ± 3.8) and lower (4.5 ± 3.7) zones (p = 0.022 and p = 0.020, respectively), and there was no significant difference in the mean CT score of the middle and lower zones (p = 1.00). The mean CT score for the anterior area (4.4 ± 4.1) was significantly lower than that for the posterior area (7.7 ± 6.3) (p = 0.003). CT findings for the patients were as follows: 25 patients (40.3%) had ground-glass opacities (GGO), 21 (33.9%), consolidation; 39 (62.9%), GGO plus a reticular pattern; 34 (54.8%), vacuolar sign; 28 (45.2%), microvascular dilation sign; 35 (56.5%), fibrotic streaks; 21 (33.9%), a subpleural line; and 33 (53.2%), a subpleural transparent line. With regard to bronchial changes seen on CT, 45 patients (72.6%) had air bronchogram, and 11 (17.7%) had bronchus distortion. In terms of pleural changes, CT showed that 30 patients (48.4%) had pleural thickening, 35 (56.5%) had pleural retraction sign, and six (9.7%) had pleural effusion. Compared with early-phase disease (≤ 7 days after the onset of symptoms), advanced-phase disease (8-14 days after the onset of symptoms) was characterized by significantly increased frequencies of GGO plus a reticular pattern, vacuolar sign, fibrotic streaks, a subpleural line, a subpleural transparent line, air bronchogram, bronchus distortion, and pleural effusion; however, GGO significantly decreased in advanced-phase disease. CONCLUSION. CT examination of patients with COVID-19 pneumonia showed a mixed and diverse pattern with both lung parenchyma and the interstitium involved. Identification of GGO and a single lesion on the initial CT scan suggested early-phase disease. CT signs of aggravation and repair coexisted in advanced-phase disease. Lesions presented with a characteristic multifocal distribution in the middle and lower lung regions and in the posterior lung area. A decreased lymphocyte count and an increased high-sensitivity C-reactive protein level were the most common laboratory findings.


Subject(s)
Coronavirus Infections/diagnostic imaging , Pneumonia, Viral/diagnostic imaging , Tomography, X-Ray Computed , Adult , Aged , COVID-19 , China , Female , Humans , Male , Middle Aged , Pandemics , Retrospective Studies
12.
Vox Sang ; 116(8): 849-861, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1402984

ABSTRACT

Growing evidence suggests that ABO blood group may play a role in the immunopathogenesis of SARS-CoV-2 infection, with group O individuals less likely to test positive and group A conferring a higher susceptibility to infection and propensity to severe disease. The level of evidence supporting an association between ABO type and SARS-CoV-2/COVID-19 ranges from small observational studies, to genome-wide-association-analyses and country-level meta-regression analyses. ABO blood group antigens are oligosaccharides expressed on red cells and other tissues (notably endothelium). There are several hypotheses to explain the differences in SARS-CoV-2 infection by ABO type. For example, anti-A and/or anti-B antibodies (e.g. present in group O individuals) could bind to corresponding antigens on the viral envelope and contribute to viral neutralization, thereby preventing target cell infection. The SARS-CoV-2 virus and SARS-CoV spike (S) proteins may be bound by anti-A isoagglutinins (e.g. present in group O and group B individuals), which may block interactions between virus and angiotensin-converting-enzyme-2-receptor, thereby preventing entry into lung epithelial cells. ABO type-associated variations in angiotensin-converting enzyme-1 activity and levels of von Willebrand factor (VWF) and factor VIII could also influence adverse outcomes, notably in group A individuals who express high VWF levels. In conclusion, group O may be associated with a lower risk of SARS-CoV-2 infection and group A may be associated with a higher risk of SARS-CoV-2 infection along with severe disease. However, prospective and mechanistic studies are needed to verify several of the proposed associations. Based on the strength of available studies, there are insufficient data for guiding policy in this regard.


Subject(s)
ABO Blood-Group System , COVID-19 , ABO Blood-Group System/genetics , Blood Grouping and Crossmatching , Humans , Prospective Studies , SARS-CoV-2
13.
Turk J Biol ; 44(3): 168-177, 2020.
Article in English | MEDLINE | ID: covidwho-1395051

ABSTRACT

A novel coronavirus (SARS-CoV-2, formerly known as nCoV-2019) that causes an acute respiratory disease has emerged in Wuhan, China and spread globally in early 2020. On January the 30th, the World Health Organization (WHO) declared spread of this virus as an epidemic and a public health emergency. With its highly contagious characteristic and long incubation time, confinement of SARS-CoV-2 requires drastic lock-down measures to be taken and therefore early diagnosis is crucial. We analysed transcriptome of SARS-CoV-2 infected human lung epithelial cells, compared it with mock-infected cells, used network-based reporter metabolite approach and integrated the transcriptome data with protein-protein interaction network to elucidate the early cellular response. Significantly affected metabolites have the potential to be used in diagnostics while pathways of protein clusters have the potential to be used as targets for supportive or novel therapeutic approaches. Our results are in accordance with the literature on response of IL6 family of cytokines and their importance, in addition, we find that matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9) with keratan sulfate synthesis pathway may play a key role in the infection. We hypothesize that MMP9 inhibitors have potential to prevent "cytokine storm" in severely affected patients.

14.
J Stem Cells Regen Med ; 16(2): 50-62, 2020.
Article in English | MEDLINE | ID: covidwho-1390025

ABSTRACT

The use of in vitro 3D organoid/colony forming assay (CFA); which mimics the in vivo environment have provided insight into the mechanisms by which lung stem cells maintain and repair the lung. In recent years, the use of CFA has markedly expanded. However, variations among laboratories in lung cell isolation methods, media used, type, origin, and processing methods of mesenchymal cells used as feeders for the epithelial colonies, and terms utilized to describe and quantify the growing colonies, have caused difficulty in reproducing results among different labs. In this study, we compared several previously described methods for lung cell isolation and culture media, to identify their influence on retrieved cells and growing colonies. We also characterized the effect of freeze/thaw, and propagation of fibroblasts on their ability to support epithelial colonies. Importantly, we suggested markers to identify fibroblast subtypes that offer the best support to alveolar stem cell proliferation. Then, we used our optimized assay to confirm the in vitro identity of recently described epithelial progenitors. We also tested the effect of hyperoxia on lung stem cells, and examined the expression of the receptors for the SARS-COV-2 virus's entry into epithelial cells, on our organoids. In summary, our findings facilitate CFA standardization, help understand how niche cell variations influence growing colonies, and confirm some of the recently described lung stem cells.

15.
Stem Cell Res Ther ; 11(1): 448, 2020 10 23.
Article in English | MEDLINE | ID: covidwho-1388825

ABSTRACT

Gene therapy is being investigated for a range of serious lung diseases, such as cystic fibrosis and emphysema. Recombinant adeno-associated virus (rAAV) is a well-established, safe, viral vector for gene delivery with multiple naturally occurring and artificial serotypes available displaying alternate cell, tissue, and species-specific tropisms. Efficient AAV serotypes for the transduction of the conducting airways have been identified for several species; however, efficient serotypes for human lung parenchyma have not yet been identified. Here, we screened the ability of multiple AAV serotypes to transduce lung bud organoids (LBOs)-a model of human lung parenchyma generated from human embryonic stem cells. Microinjection of LBOs allowed us to model transduction from the luminal surface, similar to dosing via vector inhalation. We identified the naturally occurring rAAV2 and rAAV6 serotypes, along with synthetic rAAV6 variants, as having tropism for the human lung parenchyma. Positive staining of LBOs for surfactant proteins B and C confirmed distal lung identity and suggested the suitability of these vectors for the transduction of alveolar type II cells. Our findings establish LBOs as a new model for pulmonary gene therapy and stress the relevance of LBOs as a viral infection model of the lung parenchyma as relevant in SARS-CoV-2 research.


Subject(s)
Dependovirus/genetics , Genetic Therapy/methods , Human Embryonic Stem Cells/cytology , Lung Diseases/therapy , Organoids/cytology , Cell Line , Dependovirus/immunology , Gene Transfer Techniques , Genetic Vectors/genetics , Humans , Lung/metabolism , Models, Biological , Parenchymal Tissue/cytology
16.
JCI Insight ; 5(19)2020 10 02.
Article in English | MEDLINE | ID: covidwho-1388620

ABSTRACT

The emergence of SARS-CoV-2 has created an international health crisis, and small animal models mirroring SARS-CoV-2 human disease are essential for medical countermeasure (MCM) development. Mice are refractory to SARS-CoV-2 infection owing to low-affinity binding to the murine angiotensin-converting enzyme 2 (ACE2) protein. Here, we evaluated the pathogenesis of SARS-CoV-2 in male and female mice expressing the human ACE2 gene under the control of the keratin 18 promoter (K18). In contrast to nontransgenic mice, intranasal exposure of K18-hACE2 animals to 2 different doses of SARS-CoV-2 resulted in acute disease, including weight loss, lung injury, brain infection, and lethality. Vasculitis was the most prominent finding in the lungs of infected mice. Transcriptomic analysis from lungs of infected animals showed increases in transcripts involved in lung injury and inflammatory cytokines. In the low-dose challenge groups, there was a survival advantage in the female mice, with 60% surviving infection, whereas all male mice succumbed to disease. Male mice that succumbed to disease had higher levels of inflammatory transcripts compared with female mice. To our knowledge, this is the first highly lethal murine infection model for SARS-CoV-2 and should be valuable for the study of SARS-CoV-2 pathogenesis and for the assessment of MCMs.


Subject(s)
Cause of Death , Coronavirus Infections/pathology , Disease Progression , Peptidyl-Dipeptidase A/genetics , Pneumonia, Viral/pathology , Severe Acute Respiratory Syndrome/pathology , Angiotensin-Converting Enzyme 2 , Animals , COVID-19 , Coronavirus Infections/physiopathology , Disease Models, Animal , Female , Humans , Lung/pathology , Male , Mice , Mice, Transgenic , Pandemics , Pneumonia, Viral/physiopathology , Severe Acute Respiratory Syndrome/physiopathology , Severity of Illness Index , Survival Rate , Virus Replication/genetics
18.
Sci Adv ; 6(48)2020 11.
Article in English | MEDLINE | ID: covidwho-1388431

ABSTRACT

Acute respiratory distress syndrome is associated with a robust inflammatory response that damages the vascular endothelium, impairing gas exchange. While restoration of microcapillaries is critical to avoid mortality, therapeutic targeting of this process requires a greater understanding of endothelial repair mechanisms. Here, we demonstrate that lung endothelium possesses substantial regenerative capacity and lineage tracing reveals that native endothelium is the source of vascular repair after influenza injury. Ablation of chicken ovalbumin upstream promoter-transcription factor 2 (COUP-TF2) (Nr2f2), a transcription factor implicated in developmental angiogenesis, reduced endothelial proliferation, exacerbating viral lung injury in vivo. In vitro, COUP-TF2 regulates proliferation and migration through activation of cyclin D1 and neuropilin 1. Upon influenza injury, nuclear factor κB suppresses COUP-TF2, but surviving endothelial cells ultimately reestablish vascular homeostasis dependent on restoration of COUP-TF2. Therefore, stabilization of COUP-TF2 may represent a therapeutic strategy to enhance recovery from pathogens, including H1N1 influenza and SARS-CoV-2.


Subject(s)
COUP Transcription Factor II/metabolism , Endothelial Cells/metabolism , Endothelium, Vascular/metabolism , Influenza A Virus, H1N1 Subtype , Lung/cytology , Lung/physiology , Orthomyxoviridae Infections/metabolism , Regeneration/genetics , Animals , COUP Transcription Factor II/genetics , Cell Movement/genetics , Cell Proliferation/genetics , Disease Models, Animal , Female , Gene Knockout Techniques , HEK293 Cells , Humans , Male , Mice , Mice, Transgenic , Orthomyxoviridae Infections/virology , Transfection
20.
Cell Rep Med ; 1(8): 100137, 2020 11 17.
Article in English | MEDLINE | ID: covidwho-1386734

ABSTRACT

Drug repurposing has the advantage of identifying potential treatments on a shortened timescale. In response to the pandemic spread of SARS-CoV-2, we took advantage of a high-content screen of 3,713 compounds at different stages of clinical development to identify FDA-approved compounds that reduce mucin-1 (MUC1) protein abundance. Elevated MUC1 levels predict the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) and correlate with poor clinical outcomes. Our screen identifies fostamatinib (R788), an inhibitor of spleen tyrosine kinase (SYK) approved for the treatment of chronic immune thrombocytopenia, as a repurposing candidate for the treatment of ALI. In vivo, fostamatinib reduces MUC1 abundance in lung epithelial cells in a mouse model of ALI. In vitro, SYK inhibition by the active metabolite R406 promotes MUC1 removal from the cell surface. Our work suggests fostamatinib as a repurposing drug candidate for ALI.

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