scholarly journals IL-17 mediated macrophage polarization increased inflammatory damage in SWI-ALI models

2020 ◽  
Author(s):  
Jiayi Zhao ◽  
Jin Pu ◽  
Rong Zhang ◽  
Jian Fan ◽  
Yiping Han ◽  
...  
Keyword(s):  
Wound Healing ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Alveolar Epithelial Cell ◽  
Macrophage Polarization ◽  
Alveolar Epithelial Cells ◽  
In Vitro Test ◽  
Alveolar Epithelial ◽  
Inflammatory Damage

Abstract BackgroundSeawater inhalation induced acute lung injury (SWI-ALI) is the common accident in daily naval training. To investigate the mechanism of SWI-ALI will help to improve the treatment effect. Alveolar macrophages (AM) is the majority of alveolar, also paly the key role in SWI-ALI repair. IL-17 also paly the key role in the innate immunity process.MethodIn this study, we used seawater induced the ALI in mouse model. And the lungs and serum were exacted at D1, D3, D7 and D14. The AM polarization were tested by flow cytometry. The IL-17 concentration were tested by ELISA. Then the IL-17 function were confirmed by in vitro test. The mouse alveolar epithelial cell and mouse AM were co-cultured. The test compared the wound healing effect of MAE with and without IL-17.ResultThe AM switch into M1 and IL-17A increased were found after seawater dosing. And the IL-17a supplement attenuated wound healing of alveolar epithelial cells through improve the polarization of AM were confirmed in vitro model.ConclusionThe high IL-I7 micro-environment will increased the inflammatory damage through induced macrophage polarization in acute lung injury. The IL-17 antagonists have the potential to increase clinical effect in SWI-ALI treatment.

scholarly journals Exosomes Derived From Alveolar Epithelial Cells Promote Alveolar Macrophage Activation Mediated by miR-92a-3p in Sepsis-Induced Acute Lung Injury

2021 ◽  
Vol 11 ◽  
Author(s):  
Fen Liu ◽  
Wei Peng ◽  
Jiaquan Chen ◽  
Zeyao Xu ◽  
Rong Jiang ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Pulmonary Inflammation ◽  
Cecal Ligation ◽  
Alveolar Epithelial Cells ◽  
Luciferase Reporter ◽  
Alveolar Epithelial

Acute lung injury (ALI) induced by sepsis is characterized by disruption of the epithelial barrier and activation of alveolar macrophages (AMs), which leads to uncontrolled pulmonary inflammation. However, effective treatments for ALI are unavailable. The exact mechanism by which the initial mediator of alveolar epithelial cells (AECs) induces inflammation remains elusive. Here we investigated the roles of AEC-derived exosomes in AM activation and sepsis-induced ALI in vivo and in vitro. Cecal ligation and puncture (CLP) was utilized to establish septic lung injury model in rats. The effect of exosomal inhibition by intratracheal GW4869 administration on lung injury was investigated. To assess the effects of AEC-derived exosomes on ALI, we treated the rat alveolar epithelial cell line RLE-6TN with LPS to induce cell damage. Exosomes from conditioned medium of LPS-treated AECs (LPS-Exos) were isolated by ultracentrifugation. The miRNAs in LPS-Exos were screened by miRNA expression profile analysis. The effects of miR-92a-3p on the function of AMs were studied. We found that intratracheal GW4869 administration ameliorated lung injury following CLP-induced ALI. LPS-Exos were taken up by AMs and activated these cells. Consistently, administration of LPS-Exos in rats significantly aggravated pulmonary inflammation and alveolar permeability. Moreover, miR-92a-3p was enriched in LPS-Exos and could be delivered to AMs. Inhibition of miR-92a-3p in AECs diminished the proinflammatory effects of LPS-Exos in vivo and in vitro. Mechanistically, miR-92a-3p activates AMs along with pulmonary inflammation. This process results in activation of the NF-κB pathway and downregulation of PTEN expression, which was confirmed by a luciferase reporter assay. In conclusion, AEC-derived exosomes activate AMs and induce pulmonary inflammation mediated by miR-92a-3p in ALI. The present findings revealed a previously unidentified role of exosomal miR-92a-3p in mediating the crosstalk between injured AEC and AMs. miR-92a-3p in AEC exosomes might represent a novel diagnostic biomarker for ALI, which may lead to a new therapeutic approach.

In vivo mitogenic action of HGF on lung epithelial cells: pulmotrophic role in lung regeneration

1996 ◽  
Vol 270 (6) ◽  
pp. L1031-L1039 ◽  
Author(s):  
H. Ohmichi ◽  
K. Matsumoto ◽  
T. Nakamura
Keyword(s):  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Dna Synthesis ◽  
Airway Epithelial Cells ◽  
Alveolar Epithelial Cells ◽  
Alveolar Epithelial ◽  
Lung Regeneration

Hepatocyte growth factor (HGF) has mitogenic, morphogenic, and motogenic activities on epithelial cells and plays important roles in regeneration of the liver and the kidney. We previously found that the expression of HGF gene is rapidly induced in the lung after acute lung injury in experimental animals and that HGF levels are elevated in blood of patients with lung diseases. To search for a possible pulmotrophic function of HGF in lung regeneration, we examined the mitogenic activity of HGF on tracheal epithelial cells in vitro and evaluated the efficacy of HGF-administration on lung regeneration after acute lung injury in mice. HGF markedly stimulated proliferation and DNA synthesis of rat tracheal epithelial cells in primary culture in a dose-dependent manner. The intravenous injection of human recombinant HGF (10 micrograms.mouse-1.day-1) into mice with acute lung injury induced by the intratracheal infusion of 10 mM HCI stimulated DNA synthesis of airway epithelial cells to levels threefold higher than those in mice with no HGF-injections, but it did not stimulate DNA synthesis of alveolar epithelial cells. However, HGF injection at higher dose (100 micrograms.mouse-1.day-1) stimulated DNA synthesis of alveolar epithelial cells in vivo. These results indicate that HGF is a potent mitogen for airway epithelial cells and alveolar epithelial cells in vivo as well as in vitro. HGF may act as pulmotrophic factor responsible for airway and alveolar regeneration during lung regeneration after acute lung injury.

scholarly journals Negative Effects of SIGIRR on TRAF6 Ubiquitination in Acute Lung Injury In Vitro

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Feng Tian ◽  
Qiang Lu ◽  
Jie Lei ◽  
Yunfeng Ni ◽  
Nianlin Xie ◽  
...  
Keyword(s):  
Immune Response ◽  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Alveolar Macrophage ◽  
Signaling Pathway ◽  
Alveolar Epithelial Cells ◽  
Alveolar Epithelial ◽  
Macrophage Cells

In this study, the effects of single immunoglobin IL-1 receptor-related protein (SIGIRR) on tumor necrosis factor- (TNF-) receptor-associated factor 6 (TRAF6) ubiquitination in acute lung injury (ALI) were evaluated in both alveolar epithelial cells and alveolar macrophage cells in vitro. Our results found that SIGIRR negatively regulated TRAF6 ubiquitination and such SIGIRR inhibition could enhance the TRAF6 expression in both alveolar epithelial cells (AECs) and alveolar macrophage cells (AMCs). SIGIRR knockdown may increase NF-κB activity via TRAF6 regulation by the classical but not the nonclassical NF-κB signaling pathway. Such modulation between TRAF6 and SIGIRR could affect cytokine secretion and exacerbate the immune response; the IL-8, NFKB1, and NFKBIA mRNA levels were reduced after SIGIRR overexpression. The current study reveals the molecular mechanisms of the negative regulatory roles of SIGIRR on the innate immune response related to the LPS/TLR-4 signaling pathway and provides evidence for strategies to clinically treat inflammatory diseases.

scholarly journals DNaseI Protects against Paraquat-Induced Acute Lung Injury and Pulmonary Fibrosis Mediated by Mitochondrial DNA

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Guo Li ◽  
Li Yuzhen ◽  
Chen Yi ◽  
Chen Xiaoxiang ◽  
Zhou Wei ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Pulmonary Fibrosis ◽  
Lung Injury ◽  
Alveolar Epithelial Cell ◽  
Disease Model ◽  
Lavage Fluid ◽  
Alveolar Epithelial ◽  
Fast Tracking ◽  
Lung Injury Model

Background. Paraquat (PQ) poisoning is a lethal toxicological challenge that served as a disease model of acute lung injury and pulmonary fibrosis, but the mechanism is undetermined and no effective treatment has been discovered.Methods and Findings. We demonstrated that PQ injures mitochondria and leads to mtDNA release. The mtDNA mediated PBMC recruitment and stimulated the alveolar epithelial cell production of TGF-β1 in vitro. The levels of mtDNA in circulation and bronchial alveolar lavage fluid (BALF) were elevated in a mouse of PQ-induced lung injury. DNaseI could protect PQ-induced lung injury and significantly improved survival. Acute lung injury markers, such as TNFα, IL-1β, and IL-6, and marker of fibrosis, collagen I, were downregulated in parallel with the elimination of mtDNA by DNaseI. These data indicate a possible mechanism for PQ-induced, mtDNA-mediated lung injury, which may be shared by other causes of lung injury, as suggested by the same protective effect of DNaseI in bleomycin-induced lung injury model. Interestingly, increased mtDNA in the BALF of patients with amyopathic dermatomyositis-interstitial lung disease can be appreciated.Conclusions. DNaseI targeting mtDNA may be a promising approach for the treatment of PQ-induced acute lung injury and pulmonary fibrosis that merits fast tracking through clinical trials.

scholarly journals p53-Fibrinolytic system and acute lung injury

Biologia ◽  
2016 ◽  
Vol 71 (10) ◽  
Author(s):  
Yashodhar Prabhakar Bhandary
Keyword(s):  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Plasminogen Activator ◽  
Lung Diseases ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Fibrinolytic System ◽  
Alveolar Epithelial ◽  
Pai 1

AbstractA different form of lung disease including acute lung injury (ALI) and its most severe form, acute respiratory distress syndrome, bronchiolitis, interstitial lung diseases and drug-induced lung diseases are often associated with alveolar epithelial cell apoptosis. Epithelial cells that are the prime important cell in the alveolar architecture produce fibrinolytic components, such as urokinase-type plasminogen activator (uPA), its receptor (uPAR), plasminogen activator inhibitor-1 (PAI-1), and tumor suppressor protein p53. The increased expression of p53, which is responsible for apoptosis of alveolar epithelial cells, and the other components of the fibrinolytic system, and a decreased alveolar fibrinolysis, are strongly involved in the pathogenesis of ALI. The fibrinolytic system, such as uPA, uPAR and PAI-1 interaction with p53, brings about the regulation of the signaling response, as well as the fibrinolytic properties, which will be useful in maintaining the unity of the cell, and also providing the signals to the cells on whether they undergo apoptosis or survival after ALI.

scholarly journals Preexposure to hyperoxia causes increased lung injury and epithelial apoptosis in mice ventilated with high tidal volumes

2010 ◽  
Vol 299 (5) ◽  
pp. L711-L719 ◽  
Author(s):  
Patrudu S. Makena ◽  
Charlean L. Luellen ◽  
Louisa Balazs ◽  
Manik C. Ghosh ◽  
Kaushik Parthasarathi ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Tidal Volume ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Lower Tidal Volume ◽  
Caspase Cleavage ◽  
Alveolar Epithelial ◽  
Severe Lung

Both high tidal volume mechanical ventilation (HV) and hyperoxia (HO) have been implicated in ventilator-induced lung injury. However, patients with acute lung injury are often exposed to HO before the application of mechanical ventilation. The potential priming of the lungs for subsequent injury by exposure to HO has not been extensively studied. We provide evidence that HO (90%) for 12 h followed by HV (25 μl/g) combined with HO for 2 or 4 h (HO-12h+HVHO-2h or -4h) induced severe lung injury in mice. Analysis of lung homogenates showed that lung injury was associated with cleavage of executioner caspases, caspases-3 and -7, and their downstream substrate poly(ADP-ribose) polymerase-1 (PARP-1). No significant lung injury or caspase cleavage was seen with either HO for 16 h or HV for up to 4 h. Ventilation for 4 h with HO (HVHO) did not cause significant lung injury without preexposure to HO. Twelve-hour HO followed by lower tidal volume (6 μl/g) mechanical ventilation failed to produce significant injury or caspase cleavage. We also evaluated the initiator caspases, caspases-8 and -9, to determine whether the death receptor or mitochondrial-mediated pathways were involved. Caspase-9 cleavage was observed in HO-12h+HVHO-2h and -4h as well as HO for 16 h. Caspase-8 activation was observed only in HO-12h+HVHO-4h, indicating the involvement of both pathways. Immunohistochemistry and in vitro stretch studies showed caspase cleavage in alveolar epithelial cells. In conclusion, preexposure to HO followed by HV produced severe lung injury associated with alveolar epithelial cell apoptosis.

scholarly journals Oxypaeoniflorin Prevents Acute Lung Injury Induced by Lipopolysaccharide through the PTEN/AKT Pathway in a Sirt1-Dependent Manner

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Fan Guohua ◽  
Zhu Tieyuan ◽  
Wang Rui ◽  
Xiong Juan
Keyword(s):  
Oxidative Stress ◽  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Inflammatory Response ◽  
Alveolar Epithelial Cells ◽  
Dependent Manner ◽  
Alveolar Epithelial ◽  
And Oxidative Stress

Acute lung injury (ALI) is featured by pulmonary edema, alveolar barrier injury, inflammatory response, and oxidative stress. The activation of Sirt1 could relieve lipopolysaccharide- (LPS-) induced murine ALI by maintaining pulmonary epithelial barrier function. Oxypaeoniflorin (Oxy) serves as a major component of Paeonia lactiflora Pall., exerting cardioprotection by activating Sirt1. However, the role of Oxy in ALI induced by LPS remains unclear. The aim of the present study is to illustrate the modulatory effects and molecular mechanisms by which Oxy operates in ALI induced by LPS. The intraperitoneal injection of LPS was performed to establish the murine ALI model while LPS-treated alveolar epithelial cells were used to mimic the in vitro ALI model. Levels of lung injury, oxidative stress, and inflammatory response were detected to observe the potential effects of Oxy on ALI. Oxy treatment mitigated lung edema, inflammatory response, and oxidative stress in mouse response to LPS, apart from improving 7-day survival. Meanwhile, Oxy also increased the expression and activity of Sirt1. Intriguingly, Sirt1 deficiency or inhibition counteracted the protective effects of Oxy treatment in LPS-treated mice or LPS-treated alveolar epithelial cells by regulating the PTEN/AKT signaling pathway. These results demonstrated that Oxy could combat ALI in vivo and in vitro through inhibiting inflammatory response and oxidative stress in a Sirt1-dependent manner. Oxy owns the potential to be a promising candidate against ALI.

H2O2 inhibits alveolar epithelial wound repair in vitro by induction of apoptosis

2004 ◽  
Vol 287 (2) ◽  
pp. L448-L453 ◽  
Author(s):  
Thomas Geiser ◽  
Masanobu Ishigaki ◽  
Coretta van Leer ◽  
Michael A. Matthay ◽  
V. Courtney Broaddus
Keyword(s):  
Acute Lung Injury ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Cell Viability ◽  
Wound Repair ◽  
Wound Edge ◽  
Alveolar Epithelial ◽  
Induction Of Apoptosis

Reactive oxygen species (ROS) are released into the alveolar space and contribute to alveolar epithelial damage in patients with acute lung injury. However, the role of ROS in alveolar repair is not known. We studied the effect of ROS in our in vitro wound healing model using either human A549 alveolar epithelial cells or primary distal lung epithelial cells. We found that H2O2 inhibited alveolar epithelial repair in a concentration-dependent manner. At similar concentrations, H2O2 also induced apoptosis, an effect seen particularly at the edge of the wound, leading us to hypothesize that apoptosis contributes to H2O2-induced inhibition of wound repair. To learn the role of apoptosis, we blocked caspases with the pan-caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp (zVAD). In the presence of H2O2, zVAD inhibited apoptosis, particularly at the wound edge and, most importantly, maintained alveolar epithelial wound repair. In H2O2-exposed cells, zVAD also maintained cell viability as judged by improved cell spreading and/or migration at the wound edge and by a more normal mitochondrial potential difference compared with cells not treated with zVAD. In conclusion, H2O2 inhibits alveolar epithelial wound repair in large part by induction of apoptosis. Inhibition of apoptosis can maintain wound repair and cell viability in the face of ROS. Inhibiting apoptosis may be a promising new approach to improve repair of the alveolar epithelium in patients with acute lung injury.

scholarly journals TRIM72 is required for effective repair of alveolar epithelial cell wounding

2014 ◽  
Vol 307 (6) ◽  
pp. L449-L459 ◽  
Author(s):  
Seong Chul Kim ◽  
Thomas Kellett ◽  
Shaohua Wang ◽  
Miyuki Nishi ◽  
Nagaraja Nagre ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Molecular Mechanisms ◽  
Striated Muscle ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Lung Cells ◽  
Alveolar Epithelial ◽  
High Tidal Volume Ventilation

The molecular mechanisms for lung cell repair are largely unknown. Previous studies identified tripartite motif protein 72 (TRIM72) from striated muscle and linked its function to tissue repair. In this study, we characterized TRIM72 expression in lung tissues and investigated the role of TRIM72 in repair of alveolar epithelial cells. In vivo injury of lung cells was introduced by high tidal volume ventilation, and repair-defective cells were labeled with postinjury administration of propidium iodide. Primary alveolar epithelial cells were isolated and membrane wounding and repair were labeled separately. Our results show that absence of TRIM72 increases susceptibility to deformation-induced lung injury whereas TRIM72 overexpression is protective. In vitro cell wounding assay revealed that TRIM72 protects alveolar epithelial cells through promoting repair rather than increasing resistance to injury. The repair function of TRIM72 in lung cells is further linked to caveolin 1. These data suggest an essential role for TRIM72 in repair of alveolar epithelial cells under plasma membrane stress failure.

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