SARS Unique Domain (SUD) of Severe Acute Respiratory Syndrome Coronavirus Induces NLRP3 Inflammasome-Dependent CXCL10-Mediated Pulmonary Inflammation

Severe acute respiratory syndrome–associated coronavirus (SARS-CoV) initiates the cytokine/chemokine storm-mediated lung injury. The SARS-CoV unique domain (SUD) with three macrodomains (N, M, and C), showing the G-quadruplex binding activity, was examined the possible role in SARS pathogenesis in this study. The chemokine profile analysis indicated that SARS-CoV SUD significantly up-regulated the expression of CXCL10, CCL5 and interleukin (IL)-1β in human lung epithelial cells and in the lung tissues of the mice intratracheally instilled with the recombinant plasmids. Among the SUD subdomains, SUD-MC substantially activated AP-1-mediated CXCL10 expression in vitro. In the wild type mice, SARS-CoV SUD-MC triggered the pulmonary infiltration of macrophages and monocytes, inducing CXCL10-mediated inflammatory responses and severe diffuse alveolar damage symptoms. Moreover, SUD-MC actuated NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome-dependent pulmonary inflammation, as confirmed by the NLRP3 inflammasome inhibitor and the NLRP3−/− mouse model. This study demonstrated that SARS-CoV SUD modulated NLRP3 inflammasome-dependent CXCL10-mediated pulmonary inflammation, providing the potential therapeutic targets for developing the antiviral agents.

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Janus Kinase Inhibition Ameliorates Ischemic Stroke Injury and Neuroinflammation Through Reducing NLRP3 Inflammasome Activation via JAK2/STAT3 Pathway Inhibition

Frontiers in Immunology ◽

10.3389/fimmu.2021.714943 ◽

2021 ◽

Vol 12 ◽

Author(s):

Hua Zhu ◽

Zhihong Jian ◽

Yi Zhong ◽

Yingze Ye ◽

Yonggang Zhang ◽

...

Keyword(s):

Ischemic Stroke ◽

Brain Tissue ◽

Proinflammatory Cytokines ◽

Nlrp3 Inflammasome ◽

Inflammatory Responses ◽

Immunofluorescence Staining ◽

Western Blots ◽

Stat3 Pathway ◽

Stat3 Signaling

BackgroundInflammatory responses play a multiphase role in the pathogenesis of cerebral ischemic stroke (IS). Ruxolitinib (Rux), a selective oral JAK 1/2 inhibitor, reduces inflammatory responses via the JAK2/STAT3 pathway. Based on its anti-inflammatory and immunosuppressive effects, we hypothesized that it may have a protective effect against stroke. The aim of this study was to investigate whether inhibition of JAK2 has a neuroprotective effect on ischemic stroke and to explore the potential molecular mechanisms.MethodsRux, MCC950 or vehicle was applied to middle cerebral artery occlusion (MCAO) mice in vivo and an oxygen-glucose deprivation/reoxygenation (OGD/R) model in vitro. After 3 days of reperfusion, neurological deficit scores, infarct volume and brain water content were assessed. Immunofluorescence staining and western blots were used to measure the expression of NLRP3 inflammasome components. The infiltrating cells were investigated by flow cytometry. Proinflammatory cytokines were assessed by RT-qPCR. The expression of the JAK2/STAT3 pathway was measured by western blots. Local STAT3 deficiency in brain tissue was established with a lentiviral vector carrying STAT3 shRNA, and chromatin immunoprecipitation (ChIP) assays were used to investigate the interplay between NLRP3 and STAT3 signaling.ResultsRux treatment improved neurological scores, decreased the infarct size and ameliorated cerebral edema 3 days after stroke. In addition, immunofluorescence staining and western blots showed that Rux application inhibited the expression of proteins related to the NLRP3 inflammasome and phosphorylated STAT3 (P-STAT3) in neurons and microglia/macrophages. Furthermore, Rux administration inhibited the expression of proinflammatory cytokines, including TNF-α, IFN-γ, HMGB1, IL-1β, IL-2, and IL-6, suggesting that Rux may alleviate IS injury by inhibiting proinflammatory reactions via JAK2/STAT3 signaling pathway regulation. Infiltrating macrophages, B, T, cells were also reduced by Rux. Local STAT3 deficiency in brain tissue decreased histone H3 and H4 acetylation on the NLRP3 promoter and NLRP3 inflammasome component expression, indicating that the NLRP3 inflammasome may be directly regulated by STAT3 signaling. Rux application suppressed lipopolysaccharide (LPS)-induced NLRP3 inflammasome secretion and JAK2/STAT3 pathway activation in the OGD/R model in vitro.ConclusionJAK2 inhibition by Rux in MCAO mice decreased STAT3 phosphorylation, thus inhibiting the expression of downstream proinflammatory cytokines and the acetylation of histones H3 and H4 on the NLRP3 promoter, resulting in the downregulation of NLRP3 inflammasome expression.

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Eosinophil-derived IL-13 promotes emphysema

European Respiratory Journal ◽

10.1183/13993003.01291-2018 ◽

2019 ◽

Vol 53 (5) ◽

pp. 1801291 ◽

Cited By ~ 10

Author(s):

Alfred D. Doyle ◽

Manali Mukherjee ◽

William E. LeSuer ◽

Tyler B. Bittner ◽

Saif M. Pasha ◽

...

Keyword(s):

Mouse Model ◽

Inflammatory Responses ◽

Pulmonary Inflammation ◽

Forced Expiratory Volume ◽

Chronic Obstructive ◽

Chronic Type ◽

Obstructive Pulmonary Disease ◽

Lung Eosinophilia

The inflammatory responses in chronic airway diseases leading to emphysema are not fully defined. We hypothesised that lung eosinophilia contributes to airspace enlargement in a mouse model and to emphysema in patients with chronic obstructive pulmonary disease (COPD).A transgenic mouse model of chronic type 2 pulmonary inflammation (I5/hE2) was used to examine eosinophil-dependent mechanisms leading to airspace enlargement. Human sputum samples were collected for translational studies examining eosinophilia and matrix metalloprotease (MMP)-12 levels in patients with chronic airways disease.Airspace enlargement was identified in I5/hE2 mice and was dependent on eosinophils. Examination of I5/hE2 bronchoalveolar lavage identified elevated MMP-12, a mediator of emphysema. We showed, in vitro, that eosinophil-derived interleukin (IL)-13 promoted alveolar macrophage MMP-12 production. Airspace enlargement in I5/hE2 mice was dependent on MMP-12 and eosinophil-derived IL-4/13. Consistent with this, MMP-12 was elevated in patients with sputum eosinophilia and computed tomography evidence of emphysema, and also negatively correlated with forced expiratory volume in 1 s.A mouse model of chronic type 2 pulmonary inflammation exhibited airspace enlargement dependent on MMP-12 and eosinophil-derived IL-4/13. In chronic airways disease patients, lung eosinophilia was associated with elevated MMP-12 levels, which was a predictor of emphysema. These findings suggest an underappreciated mechanism by which eosinophils contribute to the pathologies associated with asthma and COPD.

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CD36-Mediated Lipid Accumulation and Activation of NLRP3 Inflammasome Lead to Podocyte Injury in Obesity-Related Glomerulopathy

Mediators of Inflammation ◽

10.1155/2019/3172647 ◽

2019 ◽

Vol 2019 ◽

pp. 1-16 ◽

Cited By ~ 1

Author(s):

Jing Zhao ◽

Hong-liang Rui ◽

Min Yang ◽

Li-jun Sun ◽

Hong-rui Dong ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Lipid Accumulation ◽

Inflammatory Responses ◽

Regulatory Element ◽

Animal Experiments ◽

Receptor Protein ◽

Peroxisome Proliferator ◽

Podocyte Injury ◽

Peroxisome Proliferator Activated Receptor

Podocyte injury critically contributes to the pathogenesis of obesity-related glomerulopathy (ORG). Recently, lipid accumulation and inflammatory responses have been found to be involved in podocyte injury. This study is to explore their role and relationship in podocyte injury of ORG. In animal experiments, the ORG mice developed proteinuria, podocyte injury, and hypertriglyceridemia, accompanied with deregulated lipid metabolism, renal ectopic lipid deposition, activation of NOD-like receptor protein 3 (NLRP3) inflammasome, and secretion of IL-1β of the kidney. The expression of adipose differentiation-related protein (ADRP), CD36, sterol regulatory element-binding protein 1 (SREBP-1), and peroxisome proliferator-activated receptor α (PPARα) in renal tissue were increased. In in vitro cell experiments, after cultured podocytes were stimulated with leptin, similar to ORG mice, we found aggravated podocyte injury, formatted lipid droplet, increased expression of ADRP and CD36, activated NLRP3 inflammasome, and released IL-1β. In addition, after blocking CD36 with inhibitor sulfo-N-succinimidyl oleate (SSO) or CD36 siRNA, activation of NLRP3 inflammasome and release of IL-1β are downregulated, and podocyte injury was alleviated. However, after blocking NLRP3 with MCC950, although podocyte injury was alleviated and release of IL-1β was decreased, there was no change in the expression of CD36, ADRP, and intracellular lipid droplets. Taken together, our study suggests that CD36-mediated lipid accumulation and activation of NLRP3 inflammasome may be one of the potential pathogeneses of ORG podocyte injury.

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Modulation of the NLRP3 inflammasome by Sars-CoV-2 Envelope protein

Scientific Reports ◽

10.1038/s41598-021-04133-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mustafa Yalcinkaya ◽

Wenli Liu ◽

Mohammad N. Islam ◽

Andriana G. Kotini ◽

Galina A. Gusarova ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Inflammatory Responses ◽

Pulmonary Inflammation ◽

Protein A ◽

Lavage Fluid ◽

Viral Rna ◽

Poly I:C ◽

Inflammasome Activation ◽

E Protein ◽

Nlrp3 Inflammasome Activation

AbstractDespite the initial success of some drugs and vaccines targeting COVID-19, understanding the mechanism underlying SARS-CoV-2 disease pathogenesis remains crucial for the development of further approaches to treatment. Some patients with severe Covid-19 experience a cytokine storm and display evidence of inflammasome activation leading to increased levels of IL-1β and IL-18; however, other reports have suggested reduced inflammatory responses to Sars-Cov-2. In this study we have examined the effects of the Sars-Cov-2 envelope (E) protein, a virulence factor in coronaviruses, on inflammasome activation and pulmonary inflammation. In cultured macrophages the E protein suppressed inflammasome priming and NLRP3 inflammasome activation. Similarly, in mice transfected with E protein and treated with poly(I:C) to simulate the effects of viral RNA, the E protein, in an NLRP3-dependent fashion, reduced expression of pro-IL-1β, levels of IL-1β and IL-18 in broncho-alveolar lavage fluid, and macrophage infiltration in the lung. To simulate the effects of more advanced infection, macrophages were treated with both LPS and poly(I:C). In this setting the E protein increased NLRP3 inflammasome activation in both murine and human macrophages. Thus, the Sars-Cov-2 E protein may initially suppress the host NLRP3 inflammasome response to viral RNA while potentially increasing NLRP3 inflammasome responses in the later stages of infection. Targeting the Sars-Cov-2 E protein especially in the early stages of infection may represent a novel approach to Covid-19 therapy.

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Release of acidic store calcium is required for effective priming of the NLRP3 inflammasome

10.1101/2022.01.06.475262 ◽

2022 ◽

Author(s):

Nick Platt ◽

Dawn Shepherd ◽

Yuzhe Weng ◽

Grant Charles Churchill ◽

Antony Galione ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Calcium Release ◽

Inflammatory Responses ◽

Lysosomal Storage ◽

Release Channel ◽

Type C ◽

Niemann Pick ◽

Lysosomal Protein

The lysosome is a dynamic signaling organelle that is critical for cell functioning. It is a regulated calcium store that can contribute to Ca2+-regulated processes via both local calcium release and more globally by influencing ER Ca2+release. Here, we provide evidence from studies of an authentic mouse model of the lysosomal storage disease Niemann-Pick Type C (NPC) that has reduced lysosomal Ca2+ levels, and genetically modified mice in which the two-pore lysosomal Ca2+ release channel family are deleted that lysosomal Ca2+ signaling is required for normal pro-inflammatory responses. We demonstrate that production of the pro-inflammatory cytokine IL-1beta via the NLRP3 inflammasome is significantly reduced in murine Niemann-Pick Type C, the inhibition is selective because secretion of TNF alpha is not diminished, and it is a consequence of inefficient inflammasome priming. Synthesis of precursor ProIL-1 beta is significantly reduced in macrophages genetically deficient in the lysosomal protein Npc1, which is mutated in most clinical cases of NPC, and in wild type cells in which Npc1 activity is pharmacologically inhibited. Comparable reductions in ProIL-1 beta generation were measured in vitro and in vivo by macrophages genetically altered to lack expression of the two-pore lysosomal Ca2+ release channels Tpcn1 or Tpcn2. These data demonstrate a requirement for lysosome-dependent Ca2+ signaling in the generation of specific pro-inflammatory responses.

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Targeting NLRP3 Inflammasome Activation in Severe Asthma

Journal of Clinical Medicine ◽

10.3390/jcm8101615 ◽

2019 ◽

Vol 8 (10) ◽

pp. 1615 ◽

Cited By ~ 5

Author(s):

Efthymia Theofani ◽

Maria Semitekolou ◽

Ioannis Morianos ◽

Konstantinos Samitas ◽

Georgina Xanthou

Keyword(s):

Severe Asthma ◽

Nlrp3 Inflammasome ◽

Molecular Mechanisms ◽

Inflammatory Responses ◽

Pulmonary Inflammation ◽

Airflow Obstruction ◽

Inflammasome Activation ◽

Pyrin Domain ◽

Nlrp3 Inflammasome Activation ◽

Reversible Airflow Obstruction

Severe asthma (SA) is a chronic lung disease characterized by recurring symptoms of reversible airflow obstruction, airway hyper-responsiveness (AHR), and inflammation that is resistant to currently employed treatments. The nucleotide-binding oligomerization domain-like Receptor Family Pyrin Domain Containing 3 (NLRP3) inflammasome is an intracellular sensor that detects microbial motifs and endogenous danger signals and represents a key component of innate immune responses in the airways. Assembly of the NLRP3 inflammasome leads to caspase 1-dependent release of the pro-inflammatory cytokines IL-1β and IL-18 as well as pyroptosis. Accumulating evidence proposes that NLRP3 activation is critically involved in asthma pathogenesis. In fact, although NLRP3 facilitates the clearance of pathogens in the airways, persistent NLRP3 activation by inhaled irritants and/or innocuous environmental allergens can lead to overt pulmonary inflammation and exacerbation of asthma manifestations. Notably, administration of NLRP3 inhibitors in asthma models restrains AHR and pulmonary inflammation. Here, we provide an overview of the pathophysiology of SA, present molecular mechanisms underlying aberrant inflammatory responses in the airways, summarize recent studies pertinent to the biology and functions of NLRP3, and discuss the role of NLRP3 in the pathogenesis of asthma. Finally, we contemplate the potential of targeting NLRP3 as a novel therapeutic approach for the management of SA.

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18β-Glycyrrhetinic Acid Protectes Neonatal Rats with Hyperoxia Exposure Through Inhibiting ROS/NF-κB/NLRP3 Inflammasome

10.21203/rs.3.rs-936715/v1 ◽

2021 ◽

Author(s):

Qing Cai ◽

Ziyun Liu ◽

Xuefei Yu ◽

Xinyi Zhao ◽

Xindong Xue ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Inflammatory Responses ◽

Pulmonary Inflammation ◽

The Body ◽

Glycyrrhetinic Acid ◽

Pulmonary Insufficiency ◽

Protective Effects ◽

Neonatal Rats ◽

Alveolar Development ◽

Hyperoxia Exposure

Abstract Bronchopulmonary dysplasia (BPD) is a common devastating pulmonary complication in preterm infants. Oxygen supplementation is a lifesaving therapeutic measure used for premature infants with pulmonary insufficiency. However, oxygen toxicity is a significant trigger for BPD, and oxidative stress-induced inflammatory responses, in turn, worsens the oxidative toxicity resulting in lung injury and arresting of lung development. Glycyrrhiza radix is commonly used in the medicine and food industries. 18β-Glycyrrhetinic acid (18β-GA), a primary active ingredient of Glycyrrhiza radix, has a powerful anti-oxidative and anti-inflammatory effects. This study aimed to determine whether 18β-GA has protective effects on neonatal rats with hyperoxia exposure. Newborn Sprague-Dawley rats were kept in either 21% (normoxia) or 80% O2 (hyperoxia) continuously from postnatal day (PN) 1 to 14. 18β-GA was injected intragastrically at 50 or 100 mg/kg body weight once a day from PN 1 to 14. We examined the body weights and alveolar development, and measured ROS level and the markers of pulmonary inflammation. Mature-IL-1β and NF-κB pathway proteins, and the NLRP3 inflammasome, were assessed; concurrently, caspase-1 activity was measured. Our results indicated that hyperoxia resulted in alveolar simplification and decreased bodyweight of neonatal rats. Hyperoxia exposure increased ROS level and pulmonary inflammation, and activated NF-κB and the NLRP3 inflammasome. 18β-GA treatment decreased ROS level, inhibited the activation of NF-κB and the NLRP3 inflammasome, decreased pulmonary inflammation, improved alveolar development, and increased the bodyweight of neonatal rats with hyperoxia exposure. Our study demonstrates that 18β-GA protects neonatal rats with hyperoxia exposure through inhibiting ROS/NF-κB/NLRP3 inflammasome.

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Use of a Mechanism-based Toxicological Approach to Analyze the Pulmonary Pro-Fibrogenic Effects of Air Pollution PM2.5 Particulates

10.21203/rs.2.22194/v1 ◽

2020 ◽

Author(s):

Wei Cao ◽

Xiang Wang ◽

Ming Yan ◽

Chong Hyun Chang ◽

Joshua Kim ◽

...

Keyword(s):

Nlrp3 Inflammasome ◽

Fine Particulate Matter ◽

Lung Epithelial Cells ◽

Chronic Obstructive ◽

Inflammasome Activation ◽

Nlrp3 Inflammasome Activation ◽

Oropharyngeal Aspiration ◽

Tgf Β1

Abstract Background Airborne fine particulate matter (PM2.5) has been known capable of causing acute and chronic respiratory inflammation such as chronic obstructive pulmonary disease (COPD) and lung fibrosis. With incremental experience in the predictive toxicological approach on the potential adverse effects of nanomaterials, it is logical to explore the feasibility of using such a mechanism-based approach on PM2.5-induced lung toxicity. Results In this study, we collected a panel of eight PM2.5 samples for a comparative analysis of their pro-fibrogenic effects in the lung. These samples were collected on filters in November 2017 in Zhengzhou, Henan, China. In vitro screening shows although the PM2.5 particles did not induce significant cytotoxicity, they cause potent TNF-α and interleukin-1β (IL-1β) production in THP-1 cells as well as TGF-β1 in BEAS-2B lung epithelial cells. PM2.5 induced IL-1β production was shown to involve NLRP3 inflammasome activation, which was evidenced by the inhibited IL-1β production in NLRP3- and ASC-deficient cells and use of an inhibitor for cathepsin B, a known activation of the inflammasome through lysosomal damage pathway. Administration of PM2.5 to the lung in mice via oropharyngeal aspiration confirmed that the particles could induce TGF-β1 production in the bronchoalveolar lavage (BAL) fluid and collagen deposition in the lung at 21 days post-exposure, suggesting PM2.5 has the potential to induce pulmonary fibrosis. The ranking of the pro-fibrogenic effects by the PM2.5 samples in vivo was consistent with that of the IL-1β production in vitro. Conclusions In summary, we demonstrate that the PM2.5 is capable of inducing NLRP3 inflammasome activation and a series of cellular responses originating from the epithelial–mesenchymal trophic cell unit in the lung to induce fibrosis in vivo.

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Nelfinavir inhibits replication of severe acute respiratory syndrome coronavirus 2 in vitro

10.1101/2020.04.06.026476 ◽

2020 ◽

Cited By ~ 26

Author(s):

Norio Yamamoto ◽

Shutoku Matsuyama ◽

Tyuji Hoshino ◽

Naoki Yamamoto

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Protease Inhibitor ◽

Antiviral Agents ◽

Specific Treatment ◽

Potential Candidate ◽

Serum Concentrations ◽

Candidate Drug ◽

Approved Drugs ◽

Hiv 1

AbstractIn December 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, Hubei Province, China. No specific treatment has been established against coronavirus disease-2019 (COVID-19) so far. Therefore, it is urgently needed to identify effective antiviral agents for the treatment of this disease, and several approved drugs such as lopinavir have been evaluated. Here, we report that nelfinavir, an HIV-1 protease inhibitor, potently inhibits replication of SARS-CoV-2. The effective concentrations for 50% and 90% inhibition (EC50 and EC90) of nelfinavir were 1.13 µM and 1.76 µM respectively, the lowest of the nine HIV-1 protease inhibitors including lopinavir. The trough and peak serum concentrations of nelfinavir were three to six times higher than EC50 of this drug. These results suggest that nelfinavir is a potential candidate drug for the treatment of COVID-19 and should be assessed in patients with COVID-19.

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IL-17A-mediated expression of epithelial IL-17C promotes inflammation during acute Pseudomonas aeruginosa pneumonia

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00158.2016 ◽

2016 ◽

Vol 311 (5) ◽

pp. L1015-L1022 ◽

Cited By ~ 20

Author(s):

Lisa Wolf ◽

Sandra Sapich ◽

Anja Honecker ◽

Christopher Jungnickel ◽

Frederik Seiler ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Epithelial Cells ◽

Pulmonary Inflammation ◽

Alveolar Epithelial Cells ◽

Lung Epithelial Cells ◽

Immune Functions ◽

Alveolar Epithelial ◽

Inflammatory Protein ◽

Interleukin 17A

Lung epithelial cells are suggested to promote pathogen-induced pulmonary inflammation by the release of chemokines, resulting in enhanced recruitment of circulating leukocytes. Recent studies have shown that the interleukin-17C (IL-17C) regulates innate immune functions of epithelial cells in an autocrine manner. The aim of this study was to investigate the contribution of IL-17C to pulmonary inflammation in a mouse model of acute Pseudomonas aeruginosa pneumonia. Infection with P. aeruginosa resulted in an increased expression of IL-17C in lung tissue of wild-type mice. Numbers of neutrophils and the expression of the neutrophil-recruiting chemokines keratinocyte-derived chemokine and macrophage inflammatory protein 2 were significantly decreased in lungs of IL-17C-deficient (IL-17C−/−) mice infected with P. aeruginosa at 24 h. Systemic concentrations of interleukin-6 (IL-6) were significantly decreased in infected IL-17C−/− mice at 24 h and the survival of IL-17C−/− mice was significantly increased at 48 h. The expression of IL-17C was reduced in infected mice deficient for interleukin-17A (IL-17A), whereas pulmonary concentrations of IL-17A were not affected by the deficiency for IL-17C. Stimulation of primary alveolar epithelial cells with IL-17A resulted in a significantly increased expression of IL-17C in vitro. Our data suggest that IL-17A-mediated expression of epithelial IL-17C amplifies the release of chemokines by epithelial cells and thereby contributes to the recruitment of neutrophils and systemic inflammation during acute P. aeruginosa pneumonia.

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