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1.
Int J Mol Sci ; 23(5)2022 Feb 26.
Article in English | MEDLINE | ID: covidwho-1736945

ABSTRACT

Disruption of the alveolar-endothelial barrier caused by inflammation leads to the progression of septic acute lung injury (ALI). In the present study, we investigated the beneficial effects of simvastatin on the endotoxin lipopolysaccharide (LPS)-induced ALI and its related mechanisms. A model of ALI was induced within experimental sepsis developed by intraperitoneal injection of a single non-lethal LPS dose after short-term simvastatin pretreatment (10-40 mg/kg orally). The severity of the lung tissue inflammatory injury was expressed as pulmonary damage scores (PDS). Alveolar epithelial cell apoptosis was confirmed by TUNEL assay (DNA fragmentation) and expressed as an apoptotic index (AI), and immunohistochemically for cleaved caspase-3, cytochrome C, and anti-apoptotic Bcl-xL, an inhibitor of apoptosis, survivin, and transcriptional factor, NF-kB/p65. Severe inflammatory injury of pulmonary parenchyma (PDS 3.33 ± 0.48) was developed after the LPS challenge, whereas simvastatin significantly and dose-dependently protected lung histology after LPS (p < 0.01). Simvastatin in a dose of 40 mg/kg showed the most significant effects in amelioration alveolar epithelial cells apoptosis, demonstrating this as a marked decrease of AI (p < 0.01 vs. LPS), cytochrome C, and cleaved caspase-3 expression. Furthermore, simvastatin significantly enhanced the expression of Bcl-xL and survivin. Finally, the expression of survivin and its regulator NF-kB/p65 in the alveolar epithelium was in strong positive correlation across the groups. Simvastatin could play a protective role against LPS-induced ALI and apoptosis of the alveolar-endothelial barrier. Taken together, these effects were seemingly mediated by inhibition of caspase 3 and cytochrome C, a finding that might be associated with the up-regulation of cell-survival survivin/NF-kB/p65 pathway and Bcl-xL.


Subject(s)
Acute Lung Injury , NF-kappa B , Acute Lung Injury/chemically induced , Acute Lung Injury/drug therapy , Acute Lung Injury/metabolism , Alveolar Epithelial Cells/metabolism , Apoptosis , Caspase 3/genetics , Caspase 3/metabolism , Cytochromes c/metabolism , Endotoxins/adverse effects , Humans , Lipopolysaccharides/toxicity , Lung/pathology , NF-kappa B/metabolism , Simvastatin/adverse effects , Survivin/genetics , Up-Regulation
2.
Sci Total Environ ; 825: 153964, 2022 Jun 15.
Article in English | MEDLINE | ID: covidwho-1689055

ABSTRACT

Fine particulate matter (PM2.5) pollution poses significant health concerns worldwide and can cause respiratory diseases. However, how it causes health problems is still poorly understood. Angiotensin-converting enzyme (ACE)2 is a terminal carboxypeptidase implicated in the functions of renin-angiotensin system (RAS) and plays a crucial role in the control of lung inflammation. To investigate whether ACE2 functions in PM2.5-induced lung inflammation, wild-type (WT) C57BL/6J mice and ACE2 knock-out (KO) mice were intratracheally instilled with PBS or PM2.5 suspension for 3 consecutive days, respectively. The concentrations of cytokines in bronchoalveolar lavage fluid (BALF) were determined by ELISA. The expression of ACE2 and ACE and activation of inflammatory signaling pathways in lung tissues were evaluated by immunofluorescence staining and Western blotting. We found that PM2.5 exposure increased ACE2 expression. Loss of ACE2 significantly elevated the levels of total proteins, total cells, and the concentrations of MCP-1, IL-1ß in BALF after PM2.5 challenge. Additionally, loss of ACE2 enhanced lung pathologies, airway resistance, and inflammatory signaling activation. Collectively, loss of ACE2 exacerbates PM2.5-induced acute lung injury in mice.


Subject(s)
Acute Lung Injury , Pneumonia , Acute Lung Injury/chemically induced , Acute Lung Injury/metabolism , Acute Lung Injury/pathology , Angiotensin-Converting Enzyme 2 , Animals , Lung/pathology , Mice , Mice, Inbred C57BL , Mice, Knockout , Particulate Matter/metabolism , Particulate Matter/toxicity
3.
Front Immunol ; 12: 791753, 2021.
Article in English | MEDLINE | ID: covidwho-1639168

ABSTRACT

Background: Infection of SARS-CoV-2 may cause acute respiratory syndrome. It has been reported that SARS-CoV-2 nucleocapsid protein (N-protein) presents early in body fluids during infection. The direct involvement of N-protein in lung injury is poorly understood. Methods: Recombinant N-protein was pretreated with polymyxin B, a lipopolysaccharide (LPS)-neutralizing agent. C57BL/6, C3H/HeJ (resistant to LPS), and C3H/HeN (control for C3H/HeJ) mice were exposed to N-protein via intratracheal administration to examine acute lung injury. In vitro, bone marrow-derived macrophages (BMDMs) were cultured with N-protein to study phosphorylation of nuclear factor kappa B (NF-ĸB) p65, macrophage polarization, and expression of proinflammatory cytokines. Results: N-protein produced acute lung injury in C57BL/6 mice, with elevated protein permeability, total cell count, neutrophil infiltration, and proinflammatory cytokines in the bronchioalveolar lavage. N-protein also induced lung injury in both C3H/HeJ and C3H/HeN mice, indicating that the effect could not be attributed to the LPS contamination. N-protein triggered phosphorylation of NF-ĸB p65 in vitro, which was abolished by both N-protein denaturation and treatment with an antibody for N-protein, demonstrating that the effect is N-protein specific. In addition, N-protein promoted M1 macrophage polarization and the expression of proinflammatory cytokines, which was also blocked by N-protein denaturation and antibody for N-protein. Furthermore, N-protein induced NF-ĸB p65 phosphorylation in the lung, while pyrrolidine dithiocarbamate, an NF-ĸB inhibitor, alleviated the effect of N-protein on acute lung injury. Conclusions: SARS-CoV-2 N-protein itself is toxic and induces acute lung injury in mice. Both N-protein and NF-ĸB pathway may be therapeutic targets for treating multi-organ injuries in Coronavirus disease 2019 (COVID-19).


Subject(s)
Acute Lung Injury/virology , COVID-19 , Coronavirus Nucleocapsid Proteins/toxicity , NF-kappa B/metabolism , Acute Lung Injury/metabolism , Animals , Mice , Mice, Inbred C3H , Mice, Inbred C57BL , Phosphoproteins/toxicity , SARS-CoV-2
4.
Pharmacol Res ; 176: 106083, 2022 02.
Article in English | MEDLINE | ID: covidwho-1638968

ABSTRACT

The pathogenic hyper-inflammatory response has been revealed as the major cause of the severity and death of the Corona Virus Disease 2019 (COVID-19). Xuanfei Baidu Decoction (XFBD) as one of the "three medicines and three prescriptions" for the clinically effective treatment of COVID-19 in China, shows unique advantages in the control of symptomatic transition from moderate to severe disease states. However, the roles of XFBD to against hyper-inflammatory response and its mechanism remain unclear. Here, we established acute lung injury (ALI) model induced by lipopolysaccharide (LPS), presenting a hyperinflammatory process to explore the pharmacodynamic effect and molecular mechanism of XFBD on ALI. The in vitro experiments demonstrated that XFBD inhibited the secretion of IL-6 and TNF-α and iNOS activity in LPS-stimulated RAW264.7 macrophages. In vivo, we confirmed that XFBD improved pulmonary injury via down-regulating the expression of proinflammatory cytokines such as IL-6, TNF-α and IL1-ß as well as macrophages and neutrophils infiltration in LPS-induced ALI mice. Mechanically, we revealed that XFBD treated LPS-induced acute lung injury through PD-1/IL17A pathway which regulates the infiltration of neutrophils and macrophages. Additionally, one major compound from XFBD, i.e. glycyrrhizic acid, shows a high binding affinity with IL17A. In conclusion, we demonstrated the therapeutic effects of XFBD, which provides the immune foundations of XFBD and fatherly support its clinical applications.


Subject(s)
Acute Lung Injury/drug therapy , Drugs, Chinese Herbal/pharmacology , Interleukin-17/metabolism , Macrophages/drug effects , Neutrophils/drug effects , Programmed Cell Death 1 Receptor/metabolism , Signal Transduction/drug effects , Acute Lung Injury/metabolism , Animals , COVID-19/drug therapy , COVID-19/metabolism , Cell Line , China , Cytokines/metabolism , Leukocyte Count/methods , Macrophages/metabolism , Male , Mice , Mice, Inbred C57BL , Neutrophils/metabolism , RAW 264.7 Cells
5.
J Med Chem ; 65(4): 2971-2987, 2022 02 24.
Article in English | MEDLINE | ID: covidwho-1616927

ABSTRACT

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is one of the most common complications in COVID-19. Elastase has been recognized as an important target to prevent ALI/ARDS in the patient of COVID-19. Cyclotheonellazole A (CTL-A) is a natural macrocyclic peptide reported to be a potent elastase inhibitor. Herein, we completed the first total synthesis of CTL-A in 24 linear steps. The key reactions include three-component MAC reactions and two late-stage oxidations. We also provided seven CTL-A analogues and elucidated preliminary structure-activity relationships. The in vivo ALI mouse model further suggested that CTL-A alleviated acute lung injury with reductions in lung edema and pathological deterioration, which is better than sivelestat, one approved elastase inhibitor. The activity of CTL-A against elastase, along with its cellular safety and well-established synthetic route, warrants further investigation of CTL-A as a candidate against COVID-19 pathogeneses.


Subject(s)
Acute Lung Injury/drug therapy , Leukocyte Elastase/antagonists & inhibitors , Peptides, Cyclic/pharmacology , Respiratory Distress Syndrome/drug therapy , Serine Proteinase Inhibitors/pharmacology , Acute Lung Injury/chemically induced , Acute Lung Injury/metabolism , Animals , Bleomycin , COVID-19/drug therapy , COVID-19/metabolism , COVID-19/pathology , Cell Line , Disease Models, Animal , Humans , Leukocyte Elastase/metabolism , Male , Mice , Mice, Inbred C57BL , Peptides, Cyclic/chemical synthesis , Peptides, Cyclic/chemistry , Respiratory Distress Syndrome/chemically induced , Respiratory Distress Syndrome/metabolism , Serine Proteinase Inhibitors/chemical synthesis , Serine Proteinase Inhibitors/chemistry
6.
Cells ; 11(2)2022 01 06.
Article in English | MEDLINE | ID: covidwho-1613628

ABSTRACT

Inflammatory lung injury is characterized by lung endothelial cell (LEC) death, alveolar epithelial cell (AEC) death, LEC-LEC junction weakening, and leukocyte infiltration, which together disrupt nutrient and oxygen transport. Subsequently, lung vascular repair is characterized by LEC and AEC regeneration and LEC-LEC junction re-annealing, which restores nutrient and oxygen delivery to the injured tissue. Pulmonary hypoxia is a characteristic feature of several inflammatory lung conditions, including acute lung injury (ALI), acute respiratory distress syndrome (ARDS), and severe coronavirus disease 2019 (COVID-19). The vascular response to hypoxia is controlled primarily by the hypoxia-inducible transcription factors (HIFs) 1 and 2. These transcription factors control the expression of a wide variety of target genes, which in turn mediate key pathophysiological processes including cell survival, differentiation, migration, and proliferation. HIF signaling in pulmonary cell types such as LECs and AECs, as well as infiltrating leukocytes, tightly regulates inflammatory lung injury and repair, in a manner that is dependent upon HIF isoform, cell type, and injury stimulus. The aim of this review is to describe the HIF-dependent regulation of inflammatory lung injury and vascular repair. The review will also discuss potential areas for future study and highlight putative targets for inflammatory lung conditions such as ALI/ARDS and severe COVID-19. In the development of HIF-targeted therapies to reduce inflammatory lung injury and/or enhance pulmonary vascular repair, it will be vital to consider HIF isoform- and cell-specificity, off-target side-effects, and the timing and delivery strategy of the therapeutic intervention.


Subject(s)
Acute Lung Injury/metabolism , Basic Helix-Loop-Helix Transcription Factors/metabolism , COVID-19/metabolism , Hypoxia-Inducible Factor 1/metabolism , Lung/metabolism , Respiratory Distress Syndrome/metabolism , SARS-CoV-2/metabolism , Signal Transduction , Acute Lung Injury/pathology , COVID-19/pathology , Humans , Lung/pathology , Respiratory Distress Syndrome/pathology
7.
Int J Mol Sci ; 22(23)2021 Nov 29.
Article in English | MEDLINE | ID: covidwho-1561718

ABSTRACT

S100A9, a pro-inflammatory alarmin, is up-regulated in inflamed tissues. However, the role of S100A9 in regulating neutrophil activation, inflammation and lung damage in sepsis is not known. Herein, we hypothesized that blocking S100A9 function may attenuate neutrophil recruitment in septic lung injury. Male C57BL/6 mice were pretreated with the S100A9 inhibitor ABR-238901 (10 mg/kg), prior to cercal ligation and puncture (CLP). Bronchoalveolar lavage fluid (BALF) and lung tissue were harvested for analysis of neutrophil infiltration as well as edema and CXC chemokine production. Blood was collected for analysis of membrane-activated complex-1 (Mac-1) expression on neutrophils as well as CXC chemokines and IL-6 in plasma. Induction of CLP markedly increased plasma levels of S100A9. ABR-238901 decreased CLP-induced neutrophil infiltration and edema formation in the lung. In addition, inhibition of S100A9 decreased the CLP-induced up-regulation of Mac-1 on neutrophils. Administration of ABR-238901 also inhibited the CLP-induced increase of CXCL-1, CXCL-2 and IL-6 in plasma and lungs. Our results suggest that S100A9 promotes neutrophil activation and pulmonary accumulation in sepsis. Targeting S100A9 function decreased formation of CXC chemokines in circulation and lungs and attenuated sepsis-induced lung damage. These novel findings suggest that S100A9 plays an important pro-inflammatory role in sepsis and could be a useful target to protect against the excessive inflammation and lung damage associated with the disease.


Subject(s)
Acute Lung Injury/prevention & control , Calgranulin B/metabolism , Neutrophil Infiltration/drug effects , Sepsis/complications , Acute Lung Injury/etiology , Acute Lung Injury/metabolism , Animals , Chemokines, CXC/metabolism , Drug Evaluation, Preclinical , Interleukin-6/metabolism , Lung/metabolism , Male , Mice, Inbred C57BL , Sepsis/immunology , Sepsis/metabolism
8.
Int J Mol Sci ; 22(23)2021 Nov 27.
Article in English | MEDLINE | ID: covidwho-1560687

ABSTRACT

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe respiratory disorders that are caused by aspiration, sepsis, trauma, and pneumonia. A clinical feature of ALI/ARDS is the acute onset of severe hypoxemia, and the mortality rate, which is estimated at 38-50%, remains high. Although prostaglandins (PGs) are detected in the bronchoalveolar lavage fluid of patients with ALI/ARDS, the role of PGF2α in ALI remains unclear. We aimed to clarify the role of PGF2α/PGF2α receptor (FP) signaling in acid-induced ALI using an FP receptor antagonist, AL8810. Intratracheal injection of hydrochloric acid (HCl) increased neutrophil migration into the lungs, leading to respiratory dysfunction. Pre-administration of AL8810 further increased these features. Moreover, pre-treatment with AL8810 enhanced the HCl-induced expression of pro-inflammatory cytokines and neutrophil migratory factors in the lungs. Administration of HCl decreased the gene expression of lung surfactant proteins, which was further reduced by co-administration of AL8810. Administration of AL8810 also increased lung edema and reduced mRNA expression of epithelial sodium channel in the lungs, indicating that AL8810 reduced fluid clearance. Furthermore, AL8810 also increased lipopolysaccharide-induced expression of adhesion molecules such as intracellular adhesion molecule-1 and E-selectin in human umbilical vein endothelial cells. These results indicate that inhibition of FP receptors by AL8810 exacerbated HCl-induced ALI.


Subject(s)
Acute Lung Injury/metabolism , Lung/drug effects , Pneumonia/metabolism , Receptors, Prostaglandin/antagonists & inhibitors , Respiratory Distress Syndrome/metabolism , Acute Lung Injury/chemically induced , Acute Lung Injury/pathology , Animals , Disease Models, Animal , Female , Hydrochloric Acid/toxicity , Lung/metabolism , Lung/pathology , Mice , Mice, Inbred C57BL , Pneumonia/chemically induced , Pneumonia/immunology , Pneumonia/pathology , Prostaglandins F/metabolism , Respiratory Distress Syndrome/chemically induced , Respiratory Distress Syndrome/pathology
9.
Int J Mol Sci ; 22(20)2021 Oct 18.
Article in English | MEDLINE | ID: covidwho-1470894

ABSTRACT

Infection caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2) in many cases is accompanied by the release of a large amount of proinflammatory cytokines in an event known as "cytokine storm", which is associated with severe coronavirus disease 2019 (COVID-19) cases and high mortality. The excessive production of proinflammatory cytokines is linked, inter alia, to the enhanced activity of receptors capable of recognizing the conservative regions of pathogens and cell debris, namely TLRs, TREM-1 and TNFR1. Here we report that peptides derived from innate immunity protein Tag7 inhibit activation of TREM-1 and TNFR1 receptors during acute inflammation. Peptides from the N-terminal fragment of Tag7 bind only to TREM-1, while peptides from the C-terminal fragment interact solely with TNFR1. Selected peptides are capable of inhibiting the production of proinflammatory cytokines both in peripheral blood mononuclear cells (PBMCs) from healthy donors and in vivo in the mouse model of acute lung injury (ALI) by diffuse alveolar damage (DAD). Treatment with peptides significantly decreases the infiltration of mononuclear cells to lungs in animals with DAD. Our findings suggest that Tag7-derived peptides might be beneficial in terms of the therapy or prevention of acute lung injury, e.g., for treating COVID-19 patients with severe pulmonary lesions.


Subject(s)
Acute Lung Injury/pathology , Cytokines/chemistry , Peptides/metabolism , Receptors, Tumor Necrosis Factor, Type I/metabolism , Triggering Receptor Expressed on Myeloid Cells-1/metabolism , Acute Lung Injury/metabolism , Animals , Cytokines/genetics , Cytokines/metabolism , Disease Models, Animal , Humans , Interferon-gamma/genetics , Interferon-gamma/metabolism , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/metabolism , Lipopolysaccharides/pharmacology , Lung/metabolism , Lung/pathology , Lymphocyte Activation/drug effects , Male , Mice , Mice, Inbred ICR , Peptides/chemistry , Peptides/pharmacology , Protein Binding , Receptors, Tumor Necrosis Factor, Type I/antagonists & inhibitors , Triggering Receptor Expressed on Myeloid Cells-1/antagonists & inhibitors
10.
J Immunol Res ; 2021: 4414544, 2021.
Article in English | MEDLINE | ID: covidwho-1443671

ABSTRACT

COVID-19 is a respiratory infection caused by the SARS-CoV-2 virus that can rapidly escalate to life-threatening pneumonia and acute respiratory distress syndrome (ARDS). Recently, extracellular high mobility group box 1 (HMGB1) has been identified as an essential component of cytokine storms that occur with COVID-19; HMGB1 levels correlate significantly with disease severity. Thus, the modulation of HMGB1 release may be vital for treating COVID-19. HMGB1 is a ubiquitous nuclear DNA-binding protein whose biological function depends on posttranslational modifications, its redox state, and its cellular localization. The acetylation of HMGB1 is a prerequisite for its translocation from the nucleus to the cytoplasm and then to the extracellular milieu. When released, HMGB1 acts as a proinflammatory cytokine that binds primarily to toll-like receptor 4 (TLR4) and RAGE, thereby stimulating immune cells, endothelial cells, and airway epithelial cells to produce cytokines, chemokines, and other inflammatory mediators. In this study, we demonstrate that inhaled [D-Ala2]-dynorphin 1-6 (leytragin), a peptide agonist of δ-opioid receptors, significantly inhibits HMGB1 secretion in mice with lipopolysaccharide- (LPS-) induced acute lung injury. The mechanism of action involves preventing HMGB1's hyperacetylation at critical lysine residues within nuclear localization sites, as well as promoting the expression of sirtuin 1 (SIRT1), an enzyme known to deacetylate HMGB1. Leytragin's effects are mediated by opioid receptors, since naloxone, an antagonist of opioid receptors, abrogates the leytragin effect on SIRT1 expression. Overall, our results identify leytragin as a promising therapeutic agent for the treatment of pulmonary inflammation associated with HMGB1 release. In a broader context, we demonstrate that the opioidergic system in the lungs may represent a promising target for the treatment of inflammatory lung diseases.


Subject(s)
Acute Lung Injury/drug therapy , Dynorphins/pharmacology , HMGB1 Protein/metabolism , Acetylation , Acute Lung Injury/metabolism , Animals , COVID-19/drug therapy , COVID-19/metabolism , Disease Models, Animal , Mice , Mice, Inbred C57BL , Receptors, Opioid/metabolism , Sirtuin 1/metabolism
11.
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
12.
Am J Physiol Lung Cell Mol Physiol ; 321(2): L477-L484, 2021 08 01.
Article in English | MEDLINE | ID: covidwho-1376529

ABSTRACT

Acute lung injury (ALI) leading to acute respiratory distress syndrome is the major cause of COVID-19 lethality. Cell entry of SARS-CoV-2 occurs via the interaction between its surface spike protein (SP) and angiotensin-converting enzyme-2 (ACE2). It is unknown if the viral spike protein alone is capable of altering lung vascular permeability in the lungs or producing lung injury in vivo. To that end, we intratracheally instilled the S1 subunit of SARS-CoV-2 spike protein (S1SP) in K18-hACE2 transgenic mice that overexpress human ACE2 and examined signs of COVID-19-associated lung injury 72 h later. Controls included K18-hACE2 mice that received saline or the intact SP and wild-type (WT) mice that received S1SP. K18-hACE2 mice instilled with S1SP exhibited a decline in body weight, dramatically increased white blood cells and protein concentrations in bronchoalveolar lavage fluid (BALF), upregulation of multiple inflammatory cytokines in BALF and serum, histological evidence of lung injury, and activation of signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways in the lung. K18-hACE2 mice that received either saline or SP exhibited little or no evidence of lung injury. WT mice that received S1SP exhibited a milder form of COVID-19 symptoms, compared with the K18-hACE2 mice. Furthermore, S1SP, but not SP, decreased cultured human pulmonary microvascular transendothelial resistance (TER) and barrier function. This is the first demonstration of a COVID-19-like response by an essential virus-encoded protein by SARS-CoV-2 in vivo. This model of COVID-19-induced ALI may assist in the investigation of new therapeutic approaches for the management of COVID-19 and other coronaviruses.


Subject(s)
Acute Lung Injury/pathology , COVID-19/complications , Cell Membrane Permeability , Endothelial Cells/pathology , Lung/pathology , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/metabolism , Acute Lung Injury/etiology , Acute Lung Injury/metabolism , Animals , Disease Models, Animal , Endothelial Cells/metabolism , Endothelial Cells/virology , Humans , Lung/metabolism , Lung/virology , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Protein Subunits , Spike Glycoprotein, Coronavirus/genetics , Virus Replication
13.
Pharmacol Res ; 163: 105224, 2021 01.
Article in English | MEDLINE | ID: covidwho-1364404

ABSTRACT

Acute lung injury (ALI) and its more severe form, acute respiratory distress syndrome (ARDS) as common life-threatening lung diseases with high mortality rates are mostly associated with acute and severe inflammation in lungs. With increasing in-depth studies of ALI/ARDS, significant breakthroughs have been made, however, there are still no effective pharmacological therapies for treatment of ALI/ARDS. Especially, the novel coronavirus pneumonia (COVID-19) is ravaging the globe, and causes severe respiratory distress syndrome. Therefore, developing new drugs for therapy of ALI/ARDS is in great demand, which might also be helpful for treatment of COVID-19. Natural compounds have always inspired drug development, and numerous natural products have shown potential therapeutic effects on ALI/ARDS. Therefore, this review focuses on the potential therapeutic effects of natural compounds on ALI and the underlying mechanisms. Overall, the review discusses 159 compounds and summarizes more than 400 references to present the protective effects of natural compounds against ALI and the underlying mechanism.


Subject(s)
Acute Lung Injury/drug therapy , Lung/drug effects , Phytochemicals/pharmacology , Respiratory Distress Syndrome/drug therapy , Acute Lung Injury/etiology , Acute Lung Injury/metabolism , Acute Lung Injury/pathology , Animals , Humans , Lung/metabolism , Lung/pathology , Phytochemicals/isolation & purification , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/pathology , Signal Transduction
14.
Am J Physiol Lung Cell Mol Physiol ; 321(2): L477-L484, 2021 08 01.
Article in English | MEDLINE | ID: covidwho-1280498

ABSTRACT

Acute lung injury (ALI) leading to acute respiratory distress syndrome is the major cause of COVID-19 lethality. Cell entry of SARS-CoV-2 occurs via the interaction between its surface spike protein (SP) and angiotensin-converting enzyme-2 (ACE2). It is unknown if the viral spike protein alone is capable of altering lung vascular permeability in the lungs or producing lung injury in vivo. To that end, we intratracheally instilled the S1 subunit of SARS-CoV-2 spike protein (S1SP) in K18-hACE2 transgenic mice that overexpress human ACE2 and examined signs of COVID-19-associated lung injury 72 h later. Controls included K18-hACE2 mice that received saline or the intact SP and wild-type (WT) mice that received S1SP. K18-hACE2 mice instilled with S1SP exhibited a decline in body weight, dramatically increased white blood cells and protein concentrations in bronchoalveolar lavage fluid (BALF), upregulation of multiple inflammatory cytokines in BALF and serum, histological evidence of lung injury, and activation of signal transducer and activator of transcription 3 (STAT3) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathways in the lung. K18-hACE2 mice that received either saline or SP exhibited little or no evidence of lung injury. WT mice that received S1SP exhibited a milder form of COVID-19 symptoms, compared with the K18-hACE2 mice. Furthermore, S1SP, but not SP, decreased cultured human pulmonary microvascular transendothelial resistance (TER) and barrier function. This is the first demonstration of a COVID-19-like response by an essential virus-encoded protein by SARS-CoV-2 in vivo. This model of COVID-19-induced ALI may assist in the investigation of new therapeutic approaches for the management of COVID-19 and other coronaviruses.


Subject(s)
Acute Lung Injury/pathology , COVID-19/complications , Cell Membrane Permeability , Endothelial Cells/pathology , Lung/pathology , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/metabolism , Acute Lung Injury/etiology , Acute Lung Injury/metabolism , Animals , Disease Models, Animal , Endothelial Cells/metabolism , Endothelial Cells/virology , Humans , Lung/metabolism , Lung/virology , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Protein Subunits , Spike Glycoprotein, Coronavirus/genetics , Virus Replication
15.
Int J Mol Sci ; 22(11)2021 May 24.
Article in English | MEDLINE | ID: covidwho-1273453

ABSTRACT

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common and devastating clinical disorders with high mortality and no specific therapy. Lipopolysaccharide (LPS) is usually used intratracheally to induce ALI in mice. The aim of this study was to examine the effects of an ultramicronized preparation of palmitoylethanolamide (um-PEA) in mice subjected to LPS-induced ALI. Histopathological analysis reveals that um-PEA reduced alteration in lung after LPS intratracheal administration. Besides, um-PEA decreased wet/dry weight ratio and myeloperoxidase, a marker of neutrophils infiltration, macrophages and total immune cells number and mast cells degranulation in lung. Moreover, um-PEA could also decrease cytokines release of interleukin (IL)-6, interleukin (IL)-1ß, tumor necrosis factor (TNF)-α and interleukin (IL)-18. Furthermore, um-PEA significantly inhibited the phosphorylation of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha (IκBα) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation in ALI, and at the same time decreased extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (p38/MAPK) expression, that was increased after LPS administration. Our study suggested that um-PEA contrasted LPS-induced ALI, exerting its potential role as an adjuvant anti-inflammatory therapeutic for treating lung injury, maybe also by p38/NF-κB pathway.


Subject(s)
Acute Lung Injury/drug therapy , Amides/pharmacology , Cytokines/metabolism , Ethanolamines/pharmacology , MAP Kinase Signaling System/drug effects , Palmitic Acids/pharmacology , Acute Lung Injury/metabolism , Acute Lung Injury/pathology , Amides/therapeutic use , Animals , Ethanolamines/therapeutic use , Immunohistochemistry , Inflammation/metabolism , Interleukin-18/metabolism , Interleukin-1beta/metabolism , Interleukin-6/metabolism , JNK Mitogen-Activated Protein Kinases/metabolism , Lipopolysaccharides/administration & dosage , Lipopolysaccharides/toxicity , Macrophages/drug effects , Macrophages/immunology , Male , Mast Cells/drug effects , Mast Cells/pathology , Mice , Mitogen-Activated Protein Kinase 1/metabolism , Mitogen-Activated Protein Kinase 3/metabolism , NF-KappaB Inhibitor alpha/metabolism , NF-kappa B/metabolism , Neutrophils/drug effects , Neutrophils/immunology , Palmitic Acids/therapeutic use , Peroxidase/metabolism , Tumor Necrosis Factor-alpha/metabolism , p38 Mitogen-Activated Protein Kinases/metabolism
16.
Int J Mol Sci ; 22(10)2021 May 15.
Article in English | MEDLINE | ID: covidwho-1236794

ABSTRACT

Acute lung injury (ALI) afflicts approximately 200,000 patients annually and has a 40% mortality rate. The COVID-19 pandemic has massively increased the rate of ALI incidence. The pathogenesis of ALI involves tissue damage from invading microbes and, in severe cases, the overexpression of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß). This study aimed to develop a therapy to normalize the excess production of inflammatory cytokines and promote tissue repair in the lipopolysaccharide (LPS)-induced ALI. Based on our previous studies, we tested the insulin-like growth factor I (IGF-I) and BTP-2 therapies. IGF-I was selected, because we and others have shown that elevated inflammatory cytokines suppress the expression of growth hormone receptors in the liver, leading to a decrease in the circulating IGF-I. IGF-I is a growth factor that increases vascular protection, enhances tissue repair, and decreases pro-inflammatory cytokines. It is also required to produce anti-inflammatory 1,25-dihydroxyvitamin D. BTP-2, an inhibitor of cytosolic calcium, was used to suppress the LPS-induced increase in cytosolic calcium, which otherwise leads to an increase in proinflammatory cytokines. We showed that LPS increased the expression of the primary inflammatory mediators such as toll like receptor-4 (TLR-4), IL-1ß, interleukin-17 (IL-17), TNF-α, and interferon-γ (IFN-γ), which were normalized by the IGF-I + BTP-2 dual therapy in the lungs, along with improved vascular gene expression markers. The histologic lung injury score was markedly elevated by LPS and reduced to normal by the combination therapy. In conclusion, the LPS-induced increases in inflammatory cytokines, vascular injuries, and lung injuries were all improved by IGF-I + BTP-2 combination therapy.


Subject(s)
Acute Lung Injury/drug therapy , Acute Lung Injury/metabolism , Anilides/pharmacology , Cytokines/metabolism , Gene Expression Regulation/drug effects , Insulin-Like Growth Factor I/pharmacology , Thiadiazoles/pharmacology , Acute Lung Injury/pathology , Acute Lung Injury/virology , Anilides/therapeutic use , Animals , COVID-19/complications , Calcium/metabolism , Calcium Channels/metabolism , Cytokines/genetics , Disease Models, Animal , Female , Gene Expression Regulation/genetics , Immunohistochemistry , Insulin-Like Growth Factor I/metabolism , Insulin-Like Growth Factor I/therapeutic use , Interferon-gamma/genetics , Interferon-gamma/metabolism , Interleukin-17/genetics , Interleukin-17/metabolism , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Lipopolysaccharides/toxicity , Mice , Mice, Inbred C57BL , Signal Transduction/drug effects , Signal Transduction/genetics , Thiadiazoles/therapeutic use , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/metabolism , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/metabolism
17.
Transl Res ; 233: 104-116, 2021 07.
Article in English | MEDLINE | ID: covidwho-1051128

ABSTRACT

The p53/p21 pathway is activated in response to cell stress. However, its role in acute lung injury has not been elucidated. Acute lung injury is associated with disruption of the alveolo-capillary barrier leading to acute respiratory distress syndrome (ARDS). Mechanical ventilation may be necessary to support gas exchange in patients with ARDS, however, high positive airway pressures can cause regional overdistension of alveolar units and aggravate lung injury. Here, we report that acute lung injury and alveolar overstretching activate the p53/p21 pathway to maintain homeostasis and avoid massive cell apoptosis. A systematic pooling of transcriptomic data from animal models of lung injury demonstrates the enrichment of specific p53- and p21-dependent gene signatures and a validated senescence profile. In a clinically relevant, murine model of acid aspiration and mechanical ventilation, we observed changes in the nuclear envelope and the underlying chromatin, DNA damage and activation of the Tp53/p21 pathway. Absence of Cdkn1a decreased the senescent response, but worsened lung injury due to increased cell apoptosis. Conversely, treatment with lopinavir and/or ritonavir led to Cdkn1a overexpression and ameliorated cell apoptosis and lung injury. The activation of these mechanisms was associated with early markers of senescence, including expression of senescence-related genes and increases in senescence-associated heterochromatin foci in alveolar cells. Autopsy samples from lungs of patients with ARDS revealed increased senescence-associated heterochromatin foci. Collectively, these results suggest that acute lung injury activates p53/p21 as an antiapoptotic mechanism to ameliorate damage, but with the side effect of induction of senescence.


Subject(s)
Acute Lung Injury/metabolism , Cyclin-Dependent Kinase Inhibitor p21/metabolism , Acids/administration & dosage , Acids/toxicity , Acute Lung Injury/etiology , Acute Lung Injury/pathology , Animals , Apoptosis , Cellular Senescence , Cyclin-Dependent Kinase Inhibitor p21/deficiency , Cyclin-Dependent Kinase Inhibitor p21/genetics , DNA Damage , Disease Models, Animal , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Respiration, Artificial/adverse effects , Respiratory Distress Syndrome/etiology , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/pathology , Signal Transduction , Stress, Mechanical , Tumor Suppressor Protein p53/deficiency , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism
19.
Int J Mol Sci ; 22(4)2021 Feb 20.
Article in English | MEDLINE | ID: covidwho-1090323

ABSTRACT

Severe COVID-19 is characterized by a "cytokine storm", the mechanism of which is not yet understood. I propose that cytokine storms result from synergistic interactions among Toll-like receptors (TLR) and nucleotide-binding oligomerization domain-like receptors (NLR) due to combined infections of SARS-CoV-2 with other microbes, mainly bacterial and fungal. This proposition is based on eight linked types of evidence and their logical connections. (1) Severe cases of COVID-19 differ from healthy controls and mild COVID-19 patients in exhibiting increased TLR4, TLR7, TLR9 and NLRP3 activity. (2) SARS-CoV-2 and related coronaviruses activate TLR3, TLR7, RIG1 and NLRP3. (3) SARS-CoV-2 cannot, therefore, account for the innate receptor activation pattern (IRAP) found in severe COVID-19 patients. (4) Severe COVID-19 also differs from its mild form in being characterized by bacterial and fungal infections. (5) Respiratory bacterial and fungal infections activate TLR2, TLR4, TLR9 and NLRP3. (6) A combination of SARS-CoV-2 with bacterial/fungal coinfections accounts for the IRAP found in severe COVID-19 and why it differs from mild cases. (7) Notably, TLR7 (viral) and TLR4 (bacterial/fungal) synergize, TLR9 and TLR4 (both bacterial/fungal) synergize and TLR2 and TLR4 (both bacterial/fungal) synergize with NLRP3 (viral and bacterial). (8) Thus, a SARS-CoV-2-bacterium/fungus coinfection produces synergistic innate activation, resulting in the hyperinflammation characteristic of a cytokine storm. Unique clinical, experimental and therapeutic predictions (such as why melatonin is effective in treating COVID-19) are discussed, and broader implications are outlined for understanding why other syndromes such as acute lung injury, acute respiratory distress syndrome and sepsis display varied cytokine storm symptoms.


Subject(s)
Acute Lung Injury/immunology , COVID-19/immunology , Cytokine Release Syndrome/immunology , NLR Proteins/immunology , Respiratory Distress Syndrome/immunology , Sepsis/immunology , Toll-Like Receptors/immunology , Acute Lung Injury/drug therapy , Acute Lung Injury/metabolism , Animals , COVID-19/drug therapy , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/metabolism , Humans , Inflammation/drug therapy , Inflammation/immunology , Respiratory Distress Syndrome/drug therapy , Respiratory Distress Syndrome/metabolism , SARS-CoV-2/immunology , Sepsis/drug therapy , Sepsis/metabolism , Toll-Like Receptors/metabolism
20.
Int J Mol Sci ; 22(4)2021 Feb 16.
Article in English | MEDLINE | ID: covidwho-1085071

ABSTRACT

Despite progress in understanding the pathophysiology of acute lung damage, currently approved treatment possibilities are limited to lung-protective ventilation, prone positioning, and supportive interventions. Various pharmacological approaches have also been tested, with neuromuscular blockers and corticosteroids considered as the most promising. However, inhibitors of phosphodiesterases (PDEs) also exert a broad spectrum of favorable effects potentially beneficial in acute lung damage. This article reviews pharmacological action and therapeutical potential of nonselective and selective PDE inhibitors and summarizes the results from available studies focused on the use of PDE inhibitors in animal models and clinical studies, including their adverse effects. The data suggest that xanthines as representatives of nonselective PDE inhibitors may reduce acute lung damage, and decrease mortality and length of hospital stay. Various (selective) PDE3, PDE4, and PDE5 inhibitors have also demonstrated stabilization of the pulmonary epithelial-endothelial barrier and reduction the sepsis- and inflammation-increased microvascular permeability, and suppression of the production of inflammatory mediators, which finally resulted in improved oxygenation and ventilatory parameters. However, the current lack of sufficient clinical evidence limits their recommendation for a broader use. A separate chapter focuses on involvement of cyclic adenosine monophosphate (cAMP) and PDE-related changes in its metabolism in association with coronavirus disease 2019 (COVID-19). The chapter illuminates perspectives of the use of PDE inhibitors as an add-on treatment based on actual experimental and clinical trials with preliminary data suggesting their potential benefit.


Subject(s)
Acute Lung Injury/drug therapy , Phosphodiesterase Inhibitors/therapeutic use , Acute Lung Injury/metabolism , Acute Lung Injury/physiopathology , Animals , COVID-19/drug therapy , COVID-19/metabolism , COVID-19/physiopathology , Cyclic AMP/metabolism , Disease Models, Animal , Humans , Phosphodiesterase Inhibitors/pharmacology , Phosphoric Diester Hydrolases/metabolism , Respiratory Distress Syndrome/drug therapy , Respiratory Distress Syndrome/metabolism , Respiratory Distress Syndrome/physiopathology , Sepsis/drug therapy , Sepsis/metabolism , Sepsis/physiopathology
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