scholarly journals Bigelovii A Protects against Lipopolysaccharide-Induced Acute Lung Injury by Blocking NF-κB and CCAAT/Enhancer-Binding ProteinδPathways

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Chunguang Yan ◽  
Fuqin Guan ◽  
Yanfei Shen ◽  
Huifang Tang ◽  
Dong Yuan ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
P38 Mapk ◽  
Inflammatory Mediators ◽  
Neutrophil Infiltration ◽  
Therapeutic Approaches ◽  
Lps Challenge ◽  
Enhancer Binding Protein ◽  
Underlying Mechanisms

Optimal methods are applied to acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS), but the mortality rate is still high. Accordingly, further studies dedicated to identify novel therapeutic approaches to ALI are urgently needed. Bigelovii A is a new natural product and may exhibit anti-inflammatory activity. Therefore, we sought to investigate its effect on lipopolysaccharide- (LPS-) induced ALI and the underlying mechanisms. We found that LPS-induced ALI was significantly alleviated by Bigelovii A treatment, characterized by reduction of proinflammatory mediator production, neutrophil infiltration, and lung permeability. Furthermore, Bigelovii A also downregulated LPS-stimulated inflammatory mediator expressionsin vitro. Moreover, both NF-κB and CCAAT/enhancer-binding proteinδ(C/EBPδ) activation were obviously attenuated by Bigelovii A treatment. Additionally, phosphorylation of both p38 MAPK and ERK1/2 (upstream signals of C/EBPδactivation) in response to LPS challenge was also inhibited by Bigelovii A. Therefore, Bigelovii A could attenuate LPS-induced inflammation by suppression of NF-κB, inflammatory mediators, and p38 MAPK/ERK1/2—C/EBPδ, inflammatory mediators signaling pathways, which provide a novel theoretical basis for the possible application of Bigelovii A in clinic.

scholarly journals The Crucial Role of PPARγ-Egr-1-Pro-Inflammatory Mediators Axis in IgG Immune Complex-Induced Acute Lung Injury

2021 ◽  
Vol 12 ◽  
Author(s):  
Chunguang Yan ◽  
Jing Chen ◽  
Yue Ding ◽  
Zetian Zhou ◽  
Bingyu Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Immune Complex ◽  
Inflammatory Mediators ◽  
Lung Inflammation ◽  
Acute Lung Inflammation ◽  
Pparγ Agonist

BackgroundThe ligand-activated transcription factor peroxisome proliferator-activated receptor (PPAR) γ plays crucial roles in diverse biological processes including cellular metabolism, differentiation, development, and immune response. However, during IgG immune complex (IgG-IC)-induced acute lung inflammation, its expression and function in the pulmonary tissue remains unknown.ObjectivesThe study is designed to determine the effect of PPARγ on IgG-IC-triggered acute lung inflammation, and the underlying mechanisms, which might provide theoretical basis for therapy of acute lung inflammation.SettingDepartment of Pathogenic Biology and Immunology, Medical School of Southeast UniversitySubjectsMice with down-regulated/up-regulated PPARγ activity or down-regulation of Early growth response protein 1 (Egr-1) expression, and the corresponding controls.InterventionsAcute lung inflammation is induced in the mice by airway deposition of IgG-IC. Activation of PPARγ is achieved by using its agonist Rosiglitazone or adenoviral vectors that could mediate overexpression of PPARγ. PPARγ activity is suppressed by application of its antagonist GW9662 or shRNA. Egr-1 expression is down-regulated by using the gene specific shRNA.Measures and Main ResultsWe find that during IgG-IC-induced acute lung inflammation, PPARγ expression at both RNA and protein levels is repressed, which is consistent with the results obtained from macrophages treated with IgG-IC. Furthermore, both in vivo and in vitro data show that PPARγ activation reduces IgG-IC-mediated pro-inflammatory mediators’ production, thereby alleviating lung injury. In terms of mechanism, we observe that the generation of Egr-1 elicited by IgG-IC is inhibited by PPARγ. As an important transcription factor, Egr-1 transcription is substantially increased by IgG-IC in both in vivo and in vitro studies, leading to augmented protein expression, thus amplifying IgG-IC-triggered expressions of inflammatory factors via association with their promoters.ConclusionDuring IgG-IC-stimulated acute lung inflammation, PPARγ activation can relieve the inflammatory response by suppressing the expression of its downstream target Egr-1 that directly binds to the promoter regions of several inflammation-associated genes. Therefore, regulation of PPARγ-Egr-1-pro-inflammatory mediators axis by PPARγ agonist Rosiglitazone may represent a novel strategy for blockade of acute lung injury.

scholarly journals Lidocaine Alleviates Sepsis-Induced Acute Lung Injury in Mice by Suppressing Tissue Factor and Matrix Metalloproteinase-2/9

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Binbin Zheng ◽  
Hongbo Yang ◽  
Jianan Zhang ◽  
Xueli Wang ◽  
Hao Sun ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Matrix Metalloproteinase ◽  
Gelatin Zymography ◽  
Neutrophil Infiltration ◽  
Negative Regulator ◽  
Matrix Metalloproteinase 2 ◽  
Cytokine Signaling

Acute lung injury (ALI) is one of the fatal symptoms of sepsis. However, there were no effective clinical treatments. TF accumulation-induced fibrin deposit formations and coagulation abnormalities in pulmonary vessels contribute to the lethality of ALI. Suppressor of cytokine signaling 3 (SOCS3) acts as an endogenous negative regulator of the TLR4/TF pathway. We hypothesized that inducing SOCS3 expression using lidocaine to suppress the TLR4/TF pathway may alleviate ALI. Hematoxylin and eosin (H&E), B-mode ultrasound, and flow cytometry were used to measure the pathological damage of mice. Gelatin zymography was used to measure matrix metalloproteinase-2/9 (MMP-2/9) activities. Western blot was used to assay the expression of protein levels. Here, we show that lidocaine could increase the survival rate of ALI mice and ameliorate the lung injury of ALI mice including reducing the edema, neutrophil infiltration, and pulmonary thrombosis formation and increasing blood flow velocity. Moreover, in vitro and in vivo, lidocaine could increase the expression of p-AMPK and SOCS3 and subsequently decrease the expression of p-ASK1, p-p38, TF, and the activity of MMP-2/9. Taken together, our study demonstrated that lidocaine could inhibit the TLR4/ASK1/TF pathway to alleviate ALI via activating AMPK-SOCS3 axis.

MRSA-Induced Endothelial Permeability and Acute Lung Injury are Attenuated by FTY720 S-Phosphonate

2021 ◽  
Author(s):  
Lichun Wang ◽  
Eleftheria Letsiou ◽  
Huashan Wang ◽  
Patrick Belvitch ◽  
Lucille Meliton ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Neutrophil Infiltration ◽  
Post Treatment ◽  
Fiber Formation ◽  
Actin Stress Fiber ◽  
Intratracheal Administration ◽  
Barrier Disruption

Disruption of the lung endothelial barrier is a hallmark of acute respiratory distress syndrome (ARDS), for which no effective pharmacologic treatments exist. Prior work has demonstrated that FTY720 S-phosphonate (Tys), an analog of sphingosine-1-phosphate (S1P) and FTY720, exhibits potent endothelial cell (EC) barrier protective properties. In this study we investigated the in vitro and in vivo efficacy of Tys against methicillin-resistant Staphylococcus aureus (MRSA), a frequent bacterial cause of ARDS. Tys protected human lung EC from barrier disruption induced by heat-killed MRSA (HK-MRSA) or staphylococcal α-toxin and attenuated MRSA-induced cytoskeletal changes associated with barrier disruption, including actin stress fiber formation and loss of peripheral VE-cadherin and cortactin. Tys inhibited Rho and MLC activation after MRSA and blocked MRSA-induced NF-κB activation and release of the pro-inflammatory cytokines, IL-6 and IL-8. In vivo, intratracheal administration of live MRSA in mice caused significant vascular leakage and leukocyte infiltration into the alveolar space. Pre- or post-treatment with Tys attenuated MRSA-induced lung permeability and levels of alveolar neutrophils. Post-treatment with Tys significantly reduced levels of BAL VCAM-1 and plasma IL-6 and KC induced by MRSA. Dynamic intravital imaging of mouse lungs demonstrated Tys attenuation of HK-MRSA-induced interstitial edema and neutrophil infiltration into lung tissue. Tys did not directly inhibit MRSA growth or viability in vitro. In conclusion, Tys inhibits lung EC barrier disruption and pro-inflammatory signaling induced by MRSA in vitro and attenuates acute lung injury induced by MRSA in vivo. These results support the potential utility of Tys as a novel ARDS therapeutic strategy.

scholarly journals VDR Attenuates Acute Lung Injury by Blocking Ang-2-Tie-2 Pathway and Renin-Angiotensin System

2013 ◽  
Vol 27 (12) ◽  
pp. 2116-2125 ◽  
Author(s):  
Juan Kong ◽  
Xiangdong Zhu ◽  
Yongyan Shi ◽  
Tianjing Liu ◽  
Yunzi Chen ◽  
...  
Keyword(s):  
Vitamin D ◽  
Acute Lung Injury ◽  
Angiotensin Ii ◽  
Lung Injury ◽  
Renin Angiotensin System ◽  
Neutrophil Infiltration ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Lps Challenge ◽  
Kinase Cascade

Acute lung injury (ALI) is a hallmark of systemic inflammation associated with high mortality. Although the vitamin D receptor (VDR) is highly expressed in the lung, its role in lung physiology remains unclear. We investigated the effect of VDR deletion on ALI using a lipopolysaccharide (LPS)-induced sepsis model. After LPS challenge VDR-null mice exhibited more severe ALI and higher mortality compared with wild-type (WT) counterparts, manifested by increased pulmonary vascular leakiness, pulmonary edema, apoptosis, neutrophil infiltration, and pulmonary inflammation, which was accompanied by excessive induction of angiopoietin (Ang)-2 and myosin light chain (MLC) phosphorylation in the lung. 1,25-Dihydroxyvitamin D blocked LPS-induced Ang-2 expression by blocking nuclear factor-κB activation in human pulmonary artery endothelial cells. The severity of lung injury seen in VDR-null mice was ameliorated by pretreatment with L1–10, an antagonist of Ang-2, suggesting that VDR signaling protects the pulmonary vascular barrier by targeting the Ang-2-Tie-2-MLC kinase cascade. Severe ALI in VDR-null mice was also accompanied by an increase in pulmonary renin and angiotensin II levels, and pretreatment of VDR-null mice with angiotensin II type 1 receptor blocker losartan partially ameliorated the severity of LPS-induced lung injury. Taken together, these observations provide evidence that the vitamin D-VDR signaling prevents lung injury by blocking the Ang-2-Tie-2-MLC kinase cascade and the renin-angiotensin system.

scholarly journals α-Mangostin Alleviated Lipopolysaccharide Induced Acute Lung Injury in Rats by Suppressing NAMPT/NAD Controlled Inflammatory Reactions

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mengqing Tao ◽  
Jia Jiang ◽  
Lin Wang ◽  
Yan Li ◽  
Qingcheng Mao ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Raw 264.7 Cells ◽  
Therapeutic Effects ◽  
Nicotinamide Phosphoribosyltransferase ◽  
Inflammatory Reactions ◽  
Hematological Analysis ◽  
Underlying Mechanisms

α-Mangostin (MAN) is a bioactive xanthone isolated from mangosteen. This study was designed to investigate its therapeutic effects on acute lung injury (ALI) and explore the underlying mechanisms of action. Rats from treatment groups were subject to oral administration of MAN for 3 consecutive days beforehand, and then ALI was induced in all the rats except for normal controls via an intraperitoneal injection with lipopolysaccharide. The severity of disease was evaluated by histological examination and hematological analysis. Protein expressions in tissues and cells were examined with immunohistochemical and immunoblotting methods, respectively. The levels of cytokines and nicotinamide adenine dinucleotide (NAD) were determined using ELISA and colorimetric kits, respectively. It was found that MAN treatment significantly improved histological conditions, reduced leucocytes counts, relieved oxidative stress, and declined TNF-α levels in ALI rats. Meanwhile, MAN treatment decreased expressions of nicotinamide phosphoribosyltransferase (NAMPT) and Sirt1 both in vivo and in vitro, which was accompanied with a synchronized decline of NAD and TNF-α. Immunoblotting assay further showed that MAN downregulated HMGB1, TLR4, and p-p65 in RAW 264.7 cells. MAN induced declines of both HMGB1/TLR4/p-p65 and TNF-α were substantially reversed by cotreatment with nicotinamide mononucleotide or NAD. These results suggest that downregulation of NAMPT/NAD by MAN treatments contributes to the alleviation of TLR4/NF-κB-mediated inflammations in macrophage, which is essential for amelioration of ALI in rats.

scholarly journals MK2 mediates macrophage activation and acute lung injury by regulating let-7e miRNA

2018 ◽  
Vol 315 (3) ◽  
pp. L371-L381 ◽  
Author(s):  
Yaxian Wu ◽  
Huiqiong He ◽  
Yunhe Ding ◽  
Sirui Liu ◽  
Depeng Zhang ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Macrophage Activation ◽  
Critical Role ◽  
Protein A ◽  
Cytokine Expression ◽  
Conditional Knockout ◽  
Lps Challenge ◽  
Tnf Α

MAPK-activated protein kinase 2 (MK2) plays a critical role in the development of inflammation. However, the modulatory mechanisms in macrophage activation and acute lung injury (ALI) have not been completely defined. Here, we reported that MK2-deficient mice (MK2−/−) protected against sepsis-induced ALI. In response to lipopolysaccharide (LPS) challenge, MK2−/− mice and myeloid cell-specific MK2 conditional knockout mice (MK2Lyz2-KO) exhibited attenuated inflammatory response, especially producing fewer amounts of tumor necrosis factor-α (TNF-α), interleukin (IL)-6, and macrophage inflammatory protein 2 (MIP-2). LPS treatment in vitro resulted in reduced cytokine expression in MK2−/− bone marrow-derived macrophages (BMDMs). Furthermore, we found that LPS-induced microRNA lethal-7e ( let-7e) expression was significantly increased in MK2−/− macrophages. Transfection of let-7e antagomirs into MK2−/− BMDM rescued LPS-induced expression of TNF-α, IL-6, and MIP-2. In contrast, transfection of let-7e mimics into MK2+/+BMDM decreased cytokine expression. Meanwhile, LPS-induced phosphorylation of cAMP response element-binding (CREB) protein, a substrate of MK2, was downregulated in MK2−/− BMDMs. Lin28, an inhibitory molecule of let-7, was significantly reduced in MK2−/− macrophages. Our results suggested that MK2 boosts LPS-induced macrophage activation and ALI via increasing activation of CREB and consequently, the expression of Lin28 and downregulation of let-7e.

scholarly journals MicroRNA-31-5p Exacerbates Lipopolysaccharide-Induced Acute Lung Injury via Inactivating Cab39/AMPKα Pathway

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Wan-li Jiang ◽  
Kao-chang Zhao ◽  
Wen Yuan ◽  
Fang Zhou ◽  
Heng-ya Song ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Oxidative Damage ◽  
Calcium Binding ◽  
Protective Effects ◽  
Compound C ◽  
Dependent Inhibition ◽  
Underlying Mechanisms

Acute lung injury (ALI) and the subsequent acute respiratory distress syndrome remain devastating diseases with high mortality rates and poor prognoses among patients in intensive care units. The present study is aimed at investigating the role and underlying mechanisms of microRNA-31-5p (miR-31-5p) on lipopolysaccharide- (LPS-) induced ALI. Mice were pretreated with miR-31-5p agomir, antagomir, and their negative controls at indicated doses for 3 consecutive days, and then they received a single intratracheal injection of LPS (5 mg/kg) for 12 h to induce ALI. MH-S murine alveolar macrophage cell lines were cultured to further verify the role of miR-31-5p in vitro. For AMP-activated protein kinase α (AMPKα) and calcium-binding protein 39 (Cab39) inhibition, compound C or lentiviral vectors were used in vivo and in vitro. We observed an upregulation of miR-31-5p in lung tissue upon LPS injection. miR-31-5p antagomir alleviated, while miR-31-5p agomir exacerbated LPS-induced inflammation, oxidative damage, and pulmonary dysfunction in vivo and in vitro. Mechanistically, miR-31-5p antagomir activated AMPKα to exert the protective effects that were abrogated by AMPKα inhibition. Further studies revealed that Cab39 was required for AMPKα activation and pulmonary protection by miR-31-5p antagomir. We provide the evidence that endogenous miR-31-5p is a key pathogenic factor for inflammation and oxidative damage during LPS-induced ALI, which is related to Cab39-dependent inhibition of AMPKα.

scholarly journals Inhibition of p38 MAPK Mitigates Lung Ischemia Reperfusion Injury by Reducing Blood–Air Barrier Hyperpermeability

2020 ◽  
Vol 11 ◽  
Author(s):  
Tiantian Wang ◽  
Chunxia Liu ◽  
Ling-hui Pan ◽  
Zhen Liu ◽  
Chang-long Li ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
P38 Mapk ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Glucose Deprivation ◽  
Endothelial Barrier ◽  
Oxygen Glucose Deprivation

Background: Lung ischemia reperfusion injury (LIRI) is a complex pathophysiological process activated by lung transplantation and acute lung injury. The p38 mitogen-activated protein kinase (MAPK) is involved in breakdown of the endothelial barrier during LIRI, but the mechanism is still unclear. Therefore, we investigated the function of p38 MAPK in LIRI in vivo and in vitro.Methods: Sprague–Dawley rats were subjected to ischemia reperfusion with or without pretreatment with a p38 MAPK inhibitor. Lung injury was assessed using hematoxylin and eosin staining, and pulmonary blood–air barrier permeability was evaluated using Evans blue staining. A rat pulmonary microvascular endothelial cell line was infected with lentiviral expressing short hairpin (sh)RNA targeting p38 MAPK and then cells were subjected to oxygen/glucose deprivation and reoxygenation (OGD/R). Markers of endothelial destruction were measured by western blot and immunofluorescence.Results:In vivo LIRI models showed structural changes indicative of lung injury and hyperpermeability of the blood–air barrier. Inhibiting p38 MAPK mitigated these effects. Oxygen/glucose deprivation and reoxygenation promoted hyperpermeability of the endothelial barrier in vitro, but knockdown of p38 MAPK attenuated cell injury; maintained endothelial barrier integrity; and partially reversed injury-induced downregulation of permeability protein AQP1, endothelial protective protein eNOS, and junction proteins ZO-1 and VE-cadherin while downregulating ICAM-1, a protein involved in destroying the endothelial barrier, and ET-1, a protein involved in endothelial dysfunction.Conclusion: Inhibition of p38 MAPK alleviates LIRI by decreasing blood–air hyperpermeability. Blocking p38 MAPK may be an effective treatment against acute lung injury.

scholarly journals Proteomic Analysis of Lung Tissue in a Rat Acute Lung Injury Model: Identification of PRDX1 as a Promoter of Inflammation

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Dongdong Liu ◽  
Pu Mao ◽  
Yongbo Huang ◽  
Yiting Liu ◽  
Xiaoqing Liu ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Lung Tissue ◽  
Critical Role ◽  
Model Identification ◽  
Airway Epithelial Cells ◽  
High Morbidity ◽  
Airway Epithelial ◽  
Lps Challenge

Acute respiratory distress syndrome (ARDS) remains a high morbidity and mortality disease entity in critically ill patients, despite decades of numerous investigations into its pathogenesis. To obtain global protein expression changes in acute lung injury (ALI) lung tissues, we employed a high-throughput proteomics method to identify key components which may be involved in the pathogenesis of ALI. In the present study, we analyzed lung tissue proteomes ofPseudomonas aeruginosa-induced ALI rats and identified eighteen proteins whose expression levels changed more than twofold as compared to normal controls. In particular, we found that PRDX1 expression in culture medium was elevated by a lipopolysaccharide (LPS) challenge in airway epithelial cellsin vitro. Furthermore, overexpression of PRDX1 increased the expression of proinflammatory cytokines interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α(TNF-α), whereas knockdown of PRDX1 led to downregulated expression of cytokines induced by LPS. In conclusion, our findings provide a global alteration in the proteome of lung tissues in the ALI rat model and indicate that PRDX1 may play a critical role in the pathogenesis of ARDS by promoting inflammation and represent a novel strategy for the development of new therapies against ALI.

Erythropoietin alleviates acute lung injury induced by ischemia-reperfusion through blocking p38 MAPK signaling

2021 ◽  
pp. 096032712110434
Author(s):  
Ling Jia ◽  
Wenjing Cui ◽  
Jiao Chen ◽  
Jinghui Yang ◽  
Xiang Xue ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Oxidative Damage ◽  
P38 Mapk ◽  
Ischemia Reperfusion ◽  
Mapk Signaling ◽  
Inflammatory Factors ◽  
Related Factors

Erythropoietin (EPO) has antiapoptotic, antioxidative, and anti-inflammatory effects on ischemia tissues and protects against acute lung injury (ALI) induced by ischemia-reperfusion (I/R). p38 mitogen-activated protein kinases (p38 MAPK) signaling is involved in the processes of I/R-induced ALI. However, the interaction of EPO with p38 MAPK signaling in I/R-induced ALI has not been reported. To explore this issue, we constructed an I/R-induced ALI model in vivo and in vitro using Sprague Dawley rats and BEAS-2B cells. Some I/R rats and hypoxia-reoxygenation (H/R)–induced cells were treated with EPO, and the others were used as control groups. The injuries of lung tissues and cells were respectively assessed by inflammatory cytokine, morphologic changes, cell viability, apoptosis, and oxidative damage–related factors. Western blot determined key proteins in the p38 MAPK signaling. Results indicated that I/R induced the increase of inflammatory factors, lung weight, filtration coefficient, bronchoalveolar lavage fluid protein content, apoptosis, neutrophil, and lung peroxidation, and H/R caused cell growth inhibition, apoptosis, and oxidative damage-related factors’ release. EPO attenuated I/R-induced injury in vivo and in vitro. Furthermore, the increase of p-p38, p-JNK, and p-ERK1/2 in lung tissues and cells induced by I/R was downregulated by EPO. Moreover, both EPO and an inhibitor of p38 MAPK (SB203580) alleviated H/R-induced cell injury. Erythropoietin along with SB203580 had more obvious protection effects than EPO alone. Collectively, EPO alleviated I/R-induced ALI by blocking p38 MAPK signaling. The interaction mechanism of EPO with p38 MAPK signaling contributes to understanding the processes of I/R-induced ALI and provides new insights for the disease treatment.

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