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1.
Signal Transduct Target Ther ; 6(1): 428, 2021 12 17.
Article in English | MEDLINE | ID: covidwho-1585884

ABSTRACT

SARS-CoV-2 infection-induced hyper-inflammation links to the acute lung injury and COVID-19 severity. Identifying the primary mediators that initiate the uncontrolled hypercytokinemia is essential for treatments. Mast cells (MCs) are strategically located at the mucosa and beneficially or detrimentally regulate immune inflammations. In this study, we showed that SARS-CoV-2-triggered MC degranulation initiated alveolar epithelial inflammation and lung injury. SARS-CoV-2 challenge induced MC degranulation in ACE-2 humanized mice and rhesus macaques, and a rapid MC degranulation could be recapitulated with Spike-RBD binding to ACE2 in cells; MC degranulation altered various signaling pathways in alveolar epithelial cells, particularly, the induction of pro-inflammatory factors and consequential disruption of tight junctions. Importantly, the administration of clinical MC stabilizers for blocking degranulation dampened SARS-CoV-2-induced production of pro-inflammatory factors and prevented lung injury. These findings uncover a novel mechanism for SARS-CoV-2 initiating lung inflammation, and suggest an off-label use of MC stabilizer as immunomodulators for COVID-19 treatments.


Subject(s)
COVID-19/metabolism , Cell Degranulation , Lung Injury/metabolism , Mast Cells/metabolism , Pulmonary Alveoli/metabolism , SARS-CoV-2/metabolism , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/genetics , Cell Line, Tumor , Female , Humans , Lung Injury/genetics , Lung Injury/virology , Macaca mulatta , Male , Mice, Inbred BALB C , Mice, Transgenic , Pulmonary Alveoli/virology , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism
2.
Sci Rep ; 11(1): 23993, 2021 12 14.
Article in English | MEDLINE | ID: covidwho-1585801

ABSTRACT

Previous work indicates that SARS-CoV-2 virus entry proteins angiotensin-converting enzyme 2 (ACE-2) and the cell surface transmembrane protease serine 2 (TMPRSS-2) are regulated by sex hormones. However, clinical studies addressing this association have yielded conflicting results. We sought to analyze the impact of sex hormones, age, and cardiovascular disease on ACE-2 and TMPRSS-2 expression in different mouse models. ACE-2 and TMPRSS-2 expression was analyzed by immunostaining in a variety of tissues obtained from FVB/N mice undergoing either gonadectomy or sham-surgery and being subjected to ischemia-reperfusion injury or transverse aortic constriction surgery. In lung tissues sex did not have a significant impact on the expression of ACE-2 and TMPRSS-2. On the contrary, following myocardial injury, female sex was associated to a lower expression of ACE-2 at the level of the kidney tubules. In addition, after myocardial injury, a significant correlation between younger age and higher expression of both ACE-2 and TMPRSS-2 was observed for lung alveoli and bronchioli, kidney tubules, and liver sinusoids. Our experimental data indicate that gonadal hormones and biological sex do not alter ACE-2 and TMPRSS-2 expression in the respiratory tract in mice, independent of disease state. Thus, sex differences in ACE-2 and TMPRSS-2 protein expression observed in mice may not explain the higher disease burden of COVID-19 among men.


Subject(s)
Aging/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Cardiomyopathies/metabolism , Castration/adverse effects , Serine Endopeptidases/metabolism , Animals , Bronchioles/metabolism , Disease Models, Animal , Female , Gene Expression Regulation , Kidney Tubules/metabolism , Liver/metabolism , Male , Mice , Pulmonary Alveoli/metabolism , Virus Internalization
3.
Cells ; 11(1)2021 12 24.
Article in English | MEDLINE | ID: covidwho-1580995

ABSTRACT

The lamellar body (LB) of the alveolar type II (ATII) cell is a lysosome-related organelle (LRO) that contains surfactant, a complex mix of mainly lipids and specific surfactant proteins. The major function of surfactant in the lung is the reduction of surface tension and stabilization of alveoli during respiration. Its lack or deficiency may cause various forms of respiratory distress syndrome (RDS). Surfactant is also part of the innate immune system in the lung, defending the organism against air-borne pathogens. The limiting (organelle) membrane that encloses the LB contains various transporters that are in part responsible for translocating lipids and other organic material into the LB. On the other hand, this membrane contains ion transporters and channels that maintain a specific internal ion composition including the acidic pH of about 5. Furthermore, P2X4 receptors, ligand gated ion channels of the danger signal ATP, are expressed in the limiting LB membrane. They play a role in boosting surfactant secretion and fluid clearance. In this review, we discuss the functions of these transporting pathways of the LB, including possible roles in disease and as therapeutic targets, including viral infections such as SARS-CoV-2.


Subject(s)
COVID-19/metabolism , Ion Channels/metabolism , Lung/metabolism , Membrane Transport Proteins/metabolism , Pulmonary Surfactants/metabolism , COVID-19/virology , Humans , Lung/virology , Organelles/metabolism , Organelles/virology , Pulmonary Alveoli/metabolism , Pulmonary Alveoli/virology , SARS-CoV-2/physiology
4.
Mol Med Rep ; 24(4)2021 Oct.
Article in English | MEDLINE | ID: covidwho-1395036

ABSTRACT

Chronic alcohol abuse increases the risk of mortality and poor outcomes in patients with acute respiratory distress syndrome. However, the underlying mechanisms remain to be elucidated. The present study aimed to investigate the effects of chronic alcohol consumption on lung injury and clarify the signaling pathways involved in the inhibition of alveolar fluid clearance (AFC). In order to produce rodent models with chronic alcohol consumption, wild­type C57BL/6 mice were treated with alcohol. A2a adenosine receptor (AR) small interfering (si)RNA or A2bAR siRNA were transfected into the lung tissue of mice and primary rat alveolar type II (ATII) cells. The rate of AFC in lung tissue was measured during exposure to lipopolysaccharide (LPS). Epithelial sodium channel (ENaC) expression was determined to investigate the mechanisms underlying alcohol­induced regulation of AFC. In the present study, exposure to alcohol reduced AFC, exacerbated pulmonary edema and worsened LPS­induced lung injury. Alcohol caused a decrease in cyclic adenosine monophosphate (cAMP) levels and inhibited α­ENaC, ß­ENaC and γ­ENaC expression levels in the lung tissue of mice and ATII cells. Furthermore, alcohol decreased α­ENaC, ß­ENaC and γ­ENaC expression levels via the A2aAR or A2bAR­cAMP signaling pathways in vitro. In conclusion, the results of the present study demonstrated that chronic alcohol consumption worsened lung injury by aggravating pulmonary edema and impairing AFC. An alcohol­induced decrease of α­ENaC, ß­ENaC and γ­ENaC expression levels by the A2AR­mediated cAMP pathway may be responsible for the exacerbated effects of chronic alcohol consumption in lung injury.


Subject(s)
Acute Lung Injury/metabolism , Alveolar Epithelial Cells/metabolism , Epithelial Sodium Channels/drug effects , Epithelial Sodium Channels/metabolism , Ethanol/pharmacology , Receptors, Adenosine A2/metabolism , Acute Lung Injury/chemically induced , Acute Lung Injury/pathology , Alveolar Epithelial Cells/pathology , Animals , Cyclic AMP/metabolism , Cytokines , Lipopolysaccharides/adverse effects , Lung/metabolism , Lung Injury/chemically induced , Lung Injury/metabolism , Lung Injury/pathology , Mice , Mice, Inbred C57BL , Pulmonary Alveoli/metabolism , Pulmonary Edema/chemically induced , Pulmonary Edema/metabolism , Pulmonary Edema/pathology , RNA Splicing Factors/genetics , RNA Splicing Factors/metabolism , Rats , Receptor, Adenosine A2A/genetics , Receptor, Adenosine A2A/metabolism , Signal Transduction
5.
Respir Res ; 22(1): 237, 2021 Aug 26.
Article in English | MEDLINE | ID: covidwho-1371969

ABSTRACT

Follow-up studies of COVID-19 patients have found lung function impairment up to six months after initial infection, but small airway function has not previously been studied. Patients (n = 20) hospitalised for a severe SARS-CoV-2 infection underwent spirometry, impulse oscillometry, and multiple measurements of alveolar nitric oxide three to six months after acute infection. None of the patients had small airway obstruction, nor increased nitric oxide concentration in the alveolar level. None of the patients had a reduced FEV1/FVC or significant bronchodilator responses in IOS or spirometry. In conclusion, we found no evidence of inflammation or dysfunction in the small airways.


Subject(s)
COVID-19/complications , COVID-19/physiopathology , Respiratory Tract Diseases/physiopathology , Adult , Aged , Female , Finland , Follow-Up Studies , Forced Expiratory Volume , Humans , Length of Stay , Male , Middle Aged , Nitric Oxide/metabolism , Pulmonary Alveoli/metabolism , Respiratory Function Tests , Respiratory Tract Diseases/etiology , Spirometry , Survivors , Vital Capacity
6.
Inflamm Res ; 70(8): 847-858, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1318745

ABSTRACT

BACKGROUND: Recognizing only sharp elevation in a short period of time, the COVID-19 SARS-CoV-2 propagation is more and more marked in the whole world. Induced inflammation afterwards infection engenders a high infiltration of immune cells and cytokines that triggers matrix metalloproteinases (MMPs) activation. These endopeptidases are mediators of the lung extracellular matrix (ECM), a basic element for alveoli structure and gas exchange. METHODS: When immune cells, MMPs, secreted cytokines and several other mediators are gathered a pathological matrix remodeling occurs. This phenomenon tends to tissue destruction in the first place and a pulmonary hypertrophy and fibrosis in the second place. FINDINGS: After pathological matrix remodeling establishment, pathological diseases take place even after infection state. Since post COVID-19 pulmonary fibrosis is an emerging complication of the disease, there is an urge to better understand and characterize the implication of ECM remodeling during SARS-CoV-2 infection. CONCLUSION: Targeting MMPs and their inhibitors could be a probable solution for occurred events since there are many cured patients that remain with severe sequels even after the end of infection.


Subject(s)
COVID-19/immunology , COVID-19/virology , Extracellular Matrix/metabolism , Matrix Metalloproteinases/metabolism , SARS-CoV-2 , Cell Communication , Cell Lineage , Cytokines/metabolism , Cytoplasm/metabolism , Fibrosis/immunology , Homeostasis , Humans , Hypertrophy , Immune System , Interferon-gamma/metabolism , Lung/physiopathology , Pulmonary Alveoli/metabolism , Pulmonary Fibrosis , Pulmonary Gas Exchange
7.
Eur Rev Med Pharmacol Sci ; 25(13): 4639-4643, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1319966

ABSTRACT

OBJECTIVE: Acute respiratory distress syndrome (ARDS) is characterized by quantitative and qualitative changes in surfactant composition, leading to surfactant dysregulation with alveolar collapse and acute respiratory hypoxic failure. Recently, surfactant has been hypothesized to play a relevant role in COVID-19, representing a strong defender against SARS-CoV-2 infection. The aim of our work was the study of immunohistochemical surfactant expression in the lungs of patients died following SARS-CoV-2 ARDS, in order to shed light on a possible therapeutic surfactant administration. PATIENTS AND METHODS: We investigated four patients who died due to ARDS following SARS-COV-2 infection and four patients submitted to lung biopsy, in the absence of SARS-CoV-2 infection. In all 8 cases, lung specimens were immunostained with anti-surfactant protein A (SP-A) and B (SP-B). RESULTS: In control subjects, reactivity for SP-B was restricted to type II alveolar cells. Immunostaining for SP-A was observed on the surface of alveolar spaces. In the COVID-19 positive lungs, immunoreactivity for SP-B was similar to that observed in control lungs; SP-A was strongly expressed along the alveolar wall. Moreover, dense aggregates of SP-A positive material were observed in the alveolar spaces. CONCLUSIONS: Our immunohistochemical data show the dysregulation of surfactant production in COVID-19 patients, particularly regarding SP-A expression. The increased presence of SP-A in condensed masses inside alveolar spaces could invalidate the therapeutic efficacy of the treatment with exogenous surfactant.


Subject(s)
COVID-19/metabolism , Immunohistochemistry , Protein Precursors/analysis , Pulmonary Surfactant-Associated Protein A/analysis , Pulmonary Surfactant-Associated Proteins/analysis , COVID-19/diagnostic imaging , Humans , Protein Precursors/genetics , Protein Precursors/metabolism , Pulmonary Alveoli/diagnostic imaging , Pulmonary Alveoli/metabolism , Pulmonary Surfactant-Associated Protein A/genetics , Pulmonary Surfactant-Associated Protein A/metabolism , Pulmonary Surfactant-Associated Proteins/genetics , Pulmonary Surfactant-Associated Proteins/metabolism , Retrospective Studies , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism
8.
Nature ; 586(7831): 785-789, 2020 10.
Article in English | MEDLINE | ID: covidwho-1281725

ABSTRACT

In the mammalian lung, an apparently homogenous mesh of capillary vessels surrounds each alveolus, forming the vast respiratory surface across which oxygen transfers to the blood1. Here we use single-cell analysis to elucidate the cell types, development, renewal and evolution of the alveolar capillary endothelium. We show that alveolar capillaries are mosaics; similar to the epithelium that lines the alveolus, the alveolar endothelium is made up of two intermingled cell types, with complex 'Swiss-cheese'-like morphologies and distinct functions. The first cell type, which we term the 'aerocyte', is specialized for gas exchange and the trafficking of leukocytes, and is unique to the lung. The other cell type, termed gCap ('general' capillary), is specialized to regulate vasomotor tone, and functions as a stem/progenitor cell in capillary homeostasis and repair. The two cell types develop from bipotent progenitors, mature gradually and are affected differently in disease and during ageing. This cell-type specialization is conserved between mouse and human lungs but is not found in alligator or turtle lungs, suggesting it arose during the evolution of the mammalian lung. The discovery of cell type specialization in alveolar capillaries transforms our understanding of the structure, function, regulation and maintenance of the air-blood barrier and gas exchange in health, disease and evolution.


Subject(s)
Capillaries/cytology , Pulmonary Alveoli/blood supply , Pulmonary Alveoli/cytology , Pulmonary Gas Exchange , Aging , Alligators and Crocodiles/anatomy & histology , Animals , Biological Evolution , Capillaries/metabolism , Cell Division , Cell Self Renewal , Cellular Senescence , Humans , Male , Mice , Pulmonary Alveoli/metabolism , Stem Cells/classification , Stem Cells/cytology , Turtles/anatomy & histology
9.
Am J Pathol ; 191(8): 1374-1384, 2021 08.
Article in English | MEDLINE | ID: covidwho-1240148

ABSTRACT

Patients with coronavirus disease 2019 (COVID-19) who are critically ill develop vascular complications characterized by thrombosis of small, medium, and large vessels. Dysfunction of the vascular endothelium due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been implicated in the pathogenesis of the COVID-19 vasculopathy. Although initial reports suggested that endothelial injury was caused directly by the virus, recent studies indicate that endothelial cells do not express angiotensin-converting enzyme 2, the receptor that SARS-CoV-2 uses to gain entry into cells, or express it at low levels and are resistant to the infection. These new findings, together with the observation that COVID-19 triggers a cytokine storm capable of injuring the endothelium and disrupting its antithrombogenic properties, favor an indirect mechanism of endothelial injury mediated locally by an augmented inflammatory reaction to infected nonendothelial cells, such as the bronchial and alveolar epithelium, and systemically by the excessive immune response to infection. Herein we review the vascular pathology of COVID-19 and critically discuss the potential mechanisms of endothelial injury in this disease.


Subject(s)
COVID-19/metabolism , Cytokine Release Syndrome/metabolism , Endothelium, Vascular/injuries , Endothelium, Vascular/metabolism , SARS-CoV-2/metabolism , Thrombosis/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Bronchi/metabolism , Bronchi/pathology , COVID-19/complications , COVID-19/pathology , COVID-19/therapy , Cytokine Release Syndrome/etiology , Cytokine Release Syndrome/pathology , Cytokine Release Syndrome/therapy , Endothelium, Vascular/pathology , Humans , Pulmonary Alveoli/metabolism , Pulmonary Alveoli/pathology , Respiratory Mucosa/metabolism , Respiratory Mucosa/pathology , Thrombosis/etiology , Thrombosis/pathology , Thrombosis/therapy
10.
J Med Virol ; 93(3): 1443-1448, 2021 03.
Article in English | MEDLINE | ID: covidwho-1196454

ABSTRACT

Our study intended to longitudinally explore the prediction effect of immunoglobulin A (IgA) on pulmonary exudation progression in COVID-19 patients. The serum IgA was tested with chemiluminescence method. Autoregressive moving average model was used to extrapolate the IgA levels before hospital admission. The positive rate of IgA and IgG in our cohort was 97% and 79.0%, respectively. In this study, the IgA levels peaks within 10-15 days after admission, while the IgG levels peaks at admission. We found that the time difference between their peaks was about 10 days. Viral RNA detection results showed that the positive rate in sputum and feces were the highest. Blood gas analysis showed that deterioration of hypoxia with the enlargement of pulmonary exudation area. And alveolar-arterial oxygen difference and oxygenation index were correlated with IgA and IgG. The results of biopsy showed that the epithelium of lung was exfoliated and the mucosa was edematous. In severe COVID-19 patients, the combination of IgA and IgG can predict the progress of pulmonary lesions and is closely related to hypoxemia and both also play an important defense role in invasion and destruction of bronchial and alveolar epithelium by SARS-CoV-2.


Subject(s)
COVID-19/pathology , COVID-19/virology , Immunoglobulin A/blood , Immunoglobulin G/blood , Sputum/virology , Aged , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/virology , Antibodies, Viral/blood , Bronchi/metabolism , Bronchi/virology , COVID-19/blood , COVID-19/metabolism , Female , Humans , Hypoxia/blood , Hypoxia/metabolism , Male , Middle Aged , Mucous Membrane/metabolism , Mucous Membrane/virology , Oxygen/metabolism , Pulmonary Alveoli/metabolism , Pulmonary Alveoli/virology , RNA, Viral/genetics , SARS-CoV-2/genetics
11.
Mol Cell Biochem ; 476(1): 93-107, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-737128

ABSTRACT

Mesenchymal stem cells (MSCs) can alleviate acute respiratory distress syndrome (ARDS), but the mechanisms involved are unclear, especially about their specific effects on cellular mitochondrial respiratory function. Thirty mice were allocated into the Control, LPS, and LPS + Bone marrow mesenchymal stem cell (BMSC) group (n = 10/group). Mouse alveolar epithelial cells (MLE-12) and macrophage cells (RAW264.7) were divided into the same groups. Pathological variation, inflammation-related factors, reactive oxygen species (ROS), ATP levels, and oxygen consumption rate (OCR) were analyzed. Pathologic features of ARDS were observed in the LPS group and were significantly alleviated by BMSCs. The trend in inflammation-related factors among the three groups was the LPS group > LPS + BMSC group > Control group. In the MLE-12 co-culture system, IL-6 was increased in the LPS group but not significantly reduced in the LPS + BMSC group. In the RAW264.7 co-culture system, IL-1ß, TNF-α, and IL-10 levels were all increased in the LPS group, IL-1ß and TNF-α levels were reduced by BMSCs, while IL-10 level kept increasing. ROS and ATP levels were increased and decreased respectively in both MLE-12 and RAW264.7 cells in the LPS groups but reversed by BMSCs. Basal OCR, ATP-linked OCR, and maximal OCR were lower in the LPS groups. Impaired basal OCR and ATP-linked OCR in MLE-12 cells were partially restored by BMSCs, while impaired basal OCR and maximal OCR in RAW264.7 cells were restored by BMSCs. BMSCs improved the mitochondrial respiration dysfunction of macrophages and alveolar epithelial cells induced by LPS, alleviated lung tissue injury, and inflammatory response in a mouse model of ARDS.


Subject(s)
Epithelium/metabolism , Mesenchymal Stem Cells/cytology , Mitochondria/metabolism , Pulmonary Alveoli/metabolism , Respiratory Distress Syndrome/metabolism , Adenosine Triphosphate/metabolism , Animals , Bone Marrow Cells/cytology , Coculture Techniques , Inflammation , Interleukin-10/metabolism , Interleukin-6/metabolism , Lipopolysaccharides/metabolism , Lung Injury/metabolism , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Oxygen Consumption , RAW 264.7 Cells
12.
Virchows Arch ; 479(4): 827-833, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1012211

ABSTRACT

We present results from clinical, radiologic, gas exchange, lung mechanics, and fibre-optic bronchoscopy-guided transbronchial biopsies in a case of acute respiratory failure due to SARS-CoV-2 (Covid-19). This report highlights the pulmonary, immunological, and inflammatory changes found during acute diffuse alveolar damage and the later organizing phase. An early diffuse alveolar damage pattern with predominant epithelial involvement with active recruitment of T cells and monocytes was observed followed by a late organizing pattern with pneumocyte hyperplasia, inflammatory infiltration, prominent endotheliitis, and secondary germinal centers. The patient's deterioration paralleling the late immuno-pathological findings based the decision to administer intravenous corticosteroids, resulting in clinical, gasometric, and radiologic improvement. We believe that real-time clinicopathological correlation, along with the description of the immunological processes at play, will contribute to the full clinical picture of Covid-19 and might lead to a more rational approach in the precise timing of anti-inflammatory, anti-cytokine, or steroid therapies.


Subject(s)
Bronchi/pathology , COVID-19/drug therapy , Steroids/therapeutic use , Aged , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/virology , Biopsy/methods , Bronchi/virology , COVID-19/pathology , COVID-19/virology , Humans , Lung/pathology , Male , Pulmonary Alveoli/metabolism , Pulmonary Alveoli/virology , Respiratory Insufficiency/drug therapy , Respiratory Insufficiency/pathology , Respiratory Insufficiency/virology , SARS-CoV-2/isolation & purification
13.
Sci Rep ; 10(1): 19522, 2020 11 11.
Article in English | MEDLINE | ID: covidwho-920619

ABSTRACT

SARS-CoV-2, the pathogenic agent of COVID-19, employs angiotensin converting enzyme-2 (ACE2) as its cell entry receptor. Clinical data reveal that in severe COVID-19, SARS-CoV-2 infects the lung, leading to a frequently lethal triad of respiratory insufficiency, acute cardiovascular failure, and coagulopathy. Physiologically, ACE2 plays a role in the regulation of three systems that could potentially be involved in the pathogenesis of severe COVID-19: the kinin-kallikrein system, resulting in acute lung inflammatory edema; the renin-angiotensin system, promoting cardiovascular instability; and the coagulation system, leading to thromboembolism. Here we assembled a healthy human lung cell atlas meta-analysis with ~ 130,000 public single-cell transcriptomes and show that key elements of the bradykinin, angiotensin and coagulation systems are co-expressed with ACE2 in alveolar cells and associated with their differentiation dynamics, which could explain how changes in ACE2 promoted by SARS-CoV-2 cell entry result in the development of the three most severe clinical components of COVID-19.


Subject(s)
Betacoronavirus/genetics , Blood Coagulation , Gene Expression Profiling , Kallikrein-Kinin System/genetics , Peptidyl-Dipeptidase A/genetics , Pulmonary Alveoli/cytology , Renin-Angiotensin System/genetics , Angiotensin-Converting Enzyme 2 , Betacoronavirus/enzymology , Betacoronavirus/physiology , Humans , Pulmonary Alveoli/metabolism , SARS-CoV-2 , Serine Endopeptidases/genetics
15.
Cell Stem Cell ; 27(6): 905-919.e10, 2020 12 03.
Article in English | MEDLINE | ID: covidwho-885442

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the cause of a present pandemic, infects human lung alveolar type 2 (hAT2) cells. Characterizing pathogenesis is crucial for developing vaccines and therapeutics. However, the lack of models mirroring the cellular physiology and pathology of hAT2 cells limits the study. Here, we develop a feeder-free, long-term, three-dimensional (3D) culture technique for hAT2 cells derived from primary human lung tissue and investigate infection response to SARS-CoV-2. By imaging-based analysis and single-cell transcriptome profiling, we reveal rapid viral replication and the increased expression of interferon-associated genes and proinflammatory genes in infected hAT2 cells, indicating a robust endogenous innate immune response. Further tracing of viral mutations acquired during transmission identifies full infection of individual cells effectively from a single viral entry. Our study provides deep insights into the pathogenesis of SARS-CoV-2 and the application of defined 3D hAT2 cultures as models for respiratory diseases.


Subject(s)
COVID-19 , Pulmonary Alveoli/virology , SARS-CoV-2/physiology , Stem Cells/virology , COVID-19/virology , Cell Culture Techniques , Culture Media , Humans , Interferons/metabolism , Models, Biological , Pulmonary Alveoli/metabolism , Pulmonary Alveoli/ultrastructure , SARS-CoV-2/ultrastructure , Transcriptome , Virus Internalization , Virus Replication
17.
Adv Mater ; 32(43): e2004901, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-756243

ABSTRACT

The COVID-19 pandemic has taken a significant toll on people worldwide, and there are currently no specific antivirus drugs or vaccines. Herein it is a therapeutic based on catalase, an antioxidant enzyme that can effectively breakdown hydrogen peroxide and minimize the downstream reactive oxygen species, which are excessively produced resulting from the infection and inflammatory process, is reported. Catalase assists to regulate production of cytokines, protect oxidative injury, and repress replication of SARS-CoV-2, as demonstrated in human leukocytes and alveolar epithelial cells, and rhesus macaques, without noticeable toxicity. Such a therapeutic can be readily manufactured at low cost as a potential treatment for COVID-19.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Antioxidants/therapeutic use , Betacoronavirus/drug effects , Catalase/therapeutic use , Coronavirus Infections/drug therapy , Pneumonia, Viral/drug therapy , Animals , Anti-Inflammatory Agents/pharmacokinetics , Antioxidants/pharmacokinetics , Betacoronavirus/physiology , COVID-19 , Catalase/pharmacokinetics , Cell Line , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Humans , Leukocytes/drug effects , Leukocytes/metabolism , Leukocytes/virology , Macaca mulatta , Mice , Mice, Inbred BALB C , Oxidative Stress/drug effects , Pandemics , Pneumonia, Viral/metabolism , Pneumonia, Viral/virology , Pulmonary Alveoli/drug effects , Pulmonary Alveoli/metabolism , Pulmonary Alveoli/virology , SARS-CoV-2 , Virus Replication/drug effects
18.
Int J Legal Med ; 134(6): 2209-2214, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-695582

ABSTRACT

A 75-year-old man presented to a French hospital with a 4-day fever after returning from a coronavirus disease-19 (COVID-19) cluster region. A reverse-transcription polymerase chain reaction test was positive for severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) using a nasopharyngeal swab sample. After he returned home and a telephone follow-up, he was found deceased 9 days after first showing symptoms. Whole-body, non-enhanced, post-mortem computed tomography (PMCT) and a forensic autopsy were performed approximately 48 h after death, with sanitary precautions. The PMCT showed bilateral and diffuse crazy-paving lung opacities, with bilateral pleural effusions. Post-mortem virology studies detected the presence of SARS-CoV-2 (B.1 lineage) in the nasopharynx, plasma, lung biopsies, pleural effusion and faeces confirming the persistence of viral ribonucleic acid 48 h after death. Microscopic examination showed that severe lung damage was responsible for his death. The main abnormality was diffuse alveolar damage, associated with different stages of inflammation and fibrosis. This case is one of the first to describe complete post-mortem data for a COVID-19 death and highlights the ability of PMCT to detect severe involvement of the lungs before autopsy in an apparently natural death. The present pathology results are concordant with previously reported findings and reinforce the disease pathogenesis hypothesis of combined viral replication with an inappropriate immune response.


Subject(s)
Betacoronavirus/pathogenicity , Coronavirus Infections/pathology , Lung/diagnostic imaging , Lung/pathology , Pneumonia, Viral/pathology , Aged , Alveolar Epithelial Cells/pathology , Autopsy , COVID-19 , Fibrin/metabolism , Humans , Hyperplasia , Male , Pandemics , Pleural Effusion/diagnostic imaging , Pleural Effusion/pathology , Pulmonary Alveoli/metabolism , Pulmonary Alveoli/pathology , SARS-CoV-2 , Tomography, X-Ray Computed
19.
Med Arch ; 74(2): 134-138, 2020 Apr.
Article in English | MEDLINE | ID: covidwho-613836

ABSTRACT

INTRODUCTION: COVID-19 is a new viral illness that can affect the lungs and airways with lethal consequences leading to the death of the patients. The ACE2 receptors were widely disturbed among body tissues such as lung, kidney, small intestine, heart, and others in different percent and considered a target for the nCOVID-19 virus. S-protein of the virus was binding to ACE2 receptors caused downregulation of endogenous anti-viral mediators, upregulation of NF-κB pathway, ROS and pro-apoptotic protein. Nrf2 was a transcription factor that's play a role in generation of anti-oxidant enzymes. AIM: To describe and establish role of Nrf2 activators for treatment COVID-19 positive patients. METHODS: We used method of analysis of the published papers with described studies about COVID-19 connected with pharmacological issues and aspects which are included in global fighting against COVID-19 infection, and how using DMF (Nrf2 activator) in clinical trial for nCOVID-19 produce positive effects in patients for reduce lung alveolar cells damage. RESULTS: we are found that Nrf2 activators an important medication that's have a role in reduce viral pathogenesis via inhibit virus entry through induce SPLI gene expression as well as inhibit TRMPSS2, upregulation of ACE2 that's make a competition with the virus on binding site, induce gene expression of anti-viral mediators such as RIG-1 and INFs, induce anti-oxidant enzymes, also they have a role in inhibit NF-κB pathway, inhibit both apoptosis proteins and gene expression of TLRs. CONCLUSION: We are concluded that use DMF (Nrf2 activator) in clinical trial for nCOVID-19 positive patients to reduce lung alveolar cells damage.


Subject(s)
Betacoronavirus/metabolism , Coronavirus Infections/metabolism , Lung/metabolism , NF-E2-Related Factor 2/metabolism , Pneumonia, Viral/metabolism , Alveolar Epithelial Cells/metabolism , COVID-19 , Humans , Pandemics , Pulmonary Alveoli/metabolism , SARS-CoV-2
20.
Med Hypotheses ; 144: 110020, 2020 Nov.
Article in English | MEDLINE | ID: covidwho-608981

ABSTRACT

Pulmonary surfactant is considered to be one of the soaps. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the other enveloped viruses become very weak against surfactant. The SARS virus binds to angiotensin-converting enzyme (ACE2) receptor and causes pneumonia. In the lung, the ACE2 receptor sits on the top of lung cells known as alveolar epithelial type II (AE2) cells. These cells play an important role in producing surfactant. Pulmonary surfactant is believed to regulate the alveolar surface tension in mammalian lungs. To our knowledge, AE2 cells are believed to act as immunoregulatory cells; however, pulmonary surfactant itself has not been believed to act as a defender against the enveloped viruses. This study hypothesises that pulmonary surfactant may be a strong defender of enveloped viruses. Therefore, old coronaviruses merely cause pneumonia. On the contrary, new SARS-CoV-2 can suppress the production of surfactant that binds to the ACE2 of AE2 cells. The coronavirus can survive in the lung tissue because of the exhaustion of pulmonary surfactant.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/prevention & control , COVID-19/physiopathology , Pneumonia, Viral/physiopathology , Pulmonary Surfactants/therapeutic use , SARS-CoV-2 , Ambroxol/therapeutic use , Bromhexine/therapeutic use , COVID-19/drug therapy , Clinical Trials as Topic , Crystallography, X-Ray , Humans , Models, Theoretical , Phagocytosis , Pregnenediones/therapeutic use , Pulmonary Alveoli/metabolism , Surface Tension , Surface-Active Agents
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