scholarly journals LncRNA HOTAIR Increases Inflammatory Responses by Activating NF-κB Pathway in LPS-Induced Acute Lung Injury

2020 ◽  
Author(s):  
XiaoMei Huang ◽  
ZeXun Mo ◽  
YuJun Li ◽  
Hua He ◽  
KangWei Wang ◽  
...  

Abstract Background Nuclear factor kappa-B (NF-κB) activation increased the expression of cytokines and further lead to lung injury was considered the main mechanism of acute lung injury (ALI). Here, we focus on exploring the potential regulatory mechanism between long noncoding RNA (LncRNA) HOX transcript antisense RNA (HOTAIR) and NF-κB on LPS-induced ALI. Methods A549 cells were then divided into 4 groups: HOTAIR group, NC group, si-HOTAIR group and si-NC group. These 4 groups were then treated with 1μg/mL lipopolysaccharides (LPS) or without LPS at 37°C for 24 h. The expression level of cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6) and LncRNA HOTAIR were evaluated by quantitative Real Time Polymerase Chain Reaction (qRT-PCR) and Enzyme-linked immunosorbent assay (ELISA). Western Blot analysis was adopted for evaluating the level of p-IκBα/IκBα and p-p65/p65. Nuclear translocation of p65 was observed by immunofluorescence staining. Results qRT-PCR and ELISA assay showed that the expression of cytokines (IL-1β, IL-6 and TNF-α) and inflammatory gene HOTAIR was remarkably increased with LPS treatment (p < 0.01). Over-expression of HOTAIR significantly increased the expression of cytokines (including IL-1β, IL-6 and TNF-α) and NF-κB pathway associated proteins (including p-IκBα/IκBα and p-p65/p65), while knockdown of HOTAIR had the opposite effect (p < 0.01). The immunofluorescence assay showed that the level of p65 in the nucleus was significantly higher in the HOTAIR group and significantly lowers in the si-HOTAIR group (p < 0.01). Conclusion HOTAIR may play a pro-inflammatory response through NF-κB pathway in LPS-induced ALI, which may provide a perspective for further understanding the pathogenic mechanism of ALI.

Antioxidants ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 198 ◽  
Author(s):  
Ba-Wool Lee ◽  
Ji-Hye Ha ◽  
Han-Gyo Shin ◽  
Seong-Hun Jeong ◽  
Da-Bin Jeon ◽  
...  

Spiraea prunifolia var. simpliciflora (SP) is traditionally used as an herbal remedy to treat fever, malaria, and emesis. This study aimed to evaluate the anti-oxidative and anti-inflammatory properties of the methanol extract of SP leaves in tumor necrosis factor (TNF)-α-stimulated NCI-H292 cells and in a lipopolysaccharide (LPS)-induced acute lung injury (ALI) mouse model. SP decreased the number of inflammatory cells and the levels of TNF-α, interleukin (IL)-1β, and IL-6 in the bronchoalveolar lavage fluid, and inflammatory cell infiltration in the lung tissues of SP-treated mice. In addition, SP significantly suppressed the mRNA and protein levels of TNF-α, IL-1β, and IL-6 in TNF-α-stimulated NCI-H292 cells. SP significantly suppressed the phosphorylation of the mitogen-activated protein kinases (MAPKs) and p65-nuclear factor-kappa B (NF-κB) in LPS-induced ALI mice and TNF-α-stimulated NCI-H292 cells. SP treatment enhanced the nuclear translocation of nuclear factor erythroid 2-related factor (Nrf2) with upregulated antioxidant enzymes and suppressed reactive oxygen species (ROS)-mediated oxidative stress in the lung tissues of LPS-induced ALI model and TNF-α-stimulated NCI-H292 cells. Collectively, SP effectively inhibited airway inflammation and ROS-mediated oxidative stress, which was closely related to its ability to induce activation of Nrf2 and inhibit the phosphorylation of MAPKs and NF-κB. These findings suggest that SP has therapeutic potential for the treatment of ALI.


2021 ◽  
Author(s):  
Zeyu Jiang ◽  
Jinyi Tan ◽  
Yan Yuan ◽  
Jiang Shen ◽  
Yan Chen

AbstractExtensive evidence has revealed the crucial roles of long non-coding RNAs (lncRNAs) in acute lung injury (ALI). This study aimed to explore the mechanism of lncRNA SNHG1 in lipopolysaccharides (LPS)-induced ALI. RT-qPCR was employed to test the levels of SNHG1, miR-421 and TIMP3 in A549 cells. Cell viability and apoptosis were assessed by CCK-8 assay and flow cytometry. ELISA assay was adopted to examine the levels of inflammatory-related cytokines, including IL-1β, IL-6 and TNF-α. The binding sequences of miR-421 and SNHG1 or TIMP3 were predicted using starBase software. Then dual-luciferase reporter and RIP assays were adopted to verify the interaction between miR-421 and SNHG1 or TIMP3. The protein level of TIMP3 was measured by western blotting. It was found that LPS stimulation downregulated SNHG1 level and SNHG1 addition decreased viability, and induced apoptosis as well as promoted inflammatory responses in LPS-treated A549 cells. SNHG1 could sponge miR-421 and SNHG1 protected A549 cells from LPS-induced injury via inhibiting miR-421. Moreover, TIMP3 was a target of miR-421. MiR-421 silence protected A549 cells against the LPS-triggered inhibition in viability, and promotion in apoptosis and inflammatory responses. SNHG1 could upregulate TIMP3 through acting as a ceRNA of miR-421 in A549 cells. Altogether, the present study elaborated that SNHG1 inhibited LPS-stimulated ALI by modulating the miR-421/TIMP3 axis.


2021 ◽  
Vol 12 ◽  
Author(s):  
An-qi Ren ◽  
Hui-jun Wang ◽  
Hai-yan Zhu ◽  
Guan Ye ◽  
Kun Li ◽  
...  

Background and Aims:Rabdosia japonica var. glaucocalyx is a traditional Chinese medicine (TCM) for various inflammatory diseases. This present work aimed to investigate the protective effects of R. japonica var. glaucocalyx glycoproteins on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and the potential mechanism.Methods: Glycoproteins (XPS) were isolated from R. japonica var. glaucocalyx, and homogeneous glycoprotein (XPS5-1) was purified from XPS. ANA-1 cells were used to observe the effect of glycoproteins on the secretion of inflammatory mediators by enzyme-linked immunosorbent assay (ELISA). Flow cytometry assay, immunofluorescence assay, and Western blot analysis were performed to detect macrophage polarization in vitro. The ALI model was induced by LPS via intratracheal instillation, and XPS (20, 40, and 80 mg/kg) was administered intragastrically 2 h later. The mechanisms of XPS against ALI were investigated by Western blot, ELISA, and immunohistochemistry.Results:In vitro, XPS and XPS5-1 downregulated LPS-induced proinflammatory mediators production including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and nitric oxide (NO) and upregulated LPS-induced IL-10 secretion. The LPS-stimulated macrophage polarization was also modulated from M1 to M2. In vivo, XPS maintained pulmonary histology with significantly reducing protein concentration and numbers of mononuclear cells in bronchoalveolar lavage fluid (BALF). The level of IL-10 in BALF was upregulated by XPS treatment. The level of cytokines including TNF-α, IL-1β, and IL-6 was downregulated. XPS also decreased infiltration of macrophages and polymorphonuclear leukocytes (PMNs) in lung. XPS suppressed the expression of key proteins in the TLR4/NF-κB signal pathway.Conclusion: XPS was demonstrated to be a potential agent for treating ALI. Our findings might provide evidence supporting the traditional application of R. japonica var. glaucocalyx in inflammation-linked diseases.


2000 ◽  
Vol 279 (6) ◽  
pp. L1137-L1145 ◽  
Author(s):  
Edward Abraham ◽  
Aaron Carmody ◽  
Robert Shenkar ◽  
John Arcaroli

Acute lung injury is characterized by accumulation of neutrophils in the lungs, accompanied by the development of interstitial edema and an intense inflammatory response. To assess the role of neutrophils as early immune effectors in hemorrhage- or endotoxemia-induced lung injury, mice were made neutropenic with cyclophosphamide or anti-neutrophil antibodies. Endotoxemia- or hemorrhage-induced lung edema was significantly reduced in neutropenic animals. Activation of the transcriptional regulatory factor nuclear factor-κB after hemorrhage or endotoxemia was diminished in the lungs of neutropenic mice compared with nonneutropenic controls. Hemorrhage or endotoxemia was followed by increases in pulmonary mRNA and protein levels for interleukin-1β (IL-1β), macrophage inflammatory protein-2 (MIP-2), and tumor necrosis factor-α (TNF-α). Endotoxin-induced increases in proinflammatory cytokine expression were greater than those found after hemorrhage. The amounts of mRNA or protein for IL-1β, MIP-2, and TNF-α were significantly lower after hemorrhage in the lungs of neutropenic versus nonneutropenic mice. Neutropenia was associated with significant reductions in IL-1β and MIP-2 but not in TNF-α expression in the lungs after endotoxemia. These experiments show that neutrophils play a centrol role in initiating acute inflammatory responses and causing injury in the lungs after hemorrhage or endotoxemia.


Author(s):  
Jiajia Jin ◽  
Hong Qian ◽  
Bing Wan ◽  
Li Zhou ◽  
Cen Chen ◽  
...  

Macrophage activation is a key contributing factor for excessive inflammatory responses of acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Geranylgeranyl diphosphate synthase (GGPPS) plays a key role in the development of inflammatory diseases. Our group previously showed that GGPPS in alveolar epithelium have deleterious effects on acute lung injury induced by LPS or mechanical ventilation. Herein, we examined the role of GGPPS in modulating macrophage activation in ALI/ARDS. We found significant increased GGPPS expression in alveolar macrophages in ARDS patients compared to healthy volunteers and in ALI mice induced by LPS. GGPPS-floxed control (GGPPSfl/fl) and myeloid-selective knockout (GGPPSfl/flLysMcre) mice were then generated. Interestingly, using a LPS-induced ALI mouse model, we showed that myeloid-specific GGPPS knockout significantly increased mortality, aggravated lung injury, and increased the accumulation of inflammatory cells, total protein, and inflammatory cytokines in BALF. In vitro, GGPPS deficiency up-regulated the production of LPS-induced IL-6, IL-1β, and TNF-α in alveolar macrophages, bone marrow-derived macrophages (BMDMs), and THP-1 cells. Mechanistically, GGPPS knockout increased phosphorylation and nuclear translocation of NF-κB p65 induced by LPS. In addition, GGPPS deficiency increased the level of GTP-Rac1, which was responsible for NF-κB activation. In conclusion, decreased expression of GGPPS in macrophages aggravates lung injury and inflammation in ARDS, at least partly by regulating Rac1-dependent NF-κB signaling. GGPPS in macrophages may represent a novel therapeutic target in ARDS.


2008 ◽  
Vol 295 (3) ◽  
pp. L497-L504 ◽  
Author(s):  
Xia Zhao ◽  
Jaroslaw W. Zmijewski ◽  
Emmanuel Lorne ◽  
Gang Liu ◽  
Young-Jun Park ◽  
...  

AMP-activated protein kinase (AMPK) is activated by increases in the intracellular AMP-to-ATP ratio and plays a central role in cellular responses to metabolic stress. Although activation of AMPK has been shown to have anti-inflammatory effects, there is little information concerning the role that AMPK may play in modulating neutrophil function and neutrophil-dependent inflammatory events, such as acute lung injury. To examine these issues, we determined the effects of pharmacological activators of AMPK, 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR) and barberine, on Toll-like receptor 4 (TLR4)-induced neutrophil activation. AICAR and barberine dose-dependently activated AMPK in murine bone marrow neutrophils. Exposure of LPS-stimulated neutrophils to AICAR or barberine inhibited release of TNF-α and IL-6, as well as degradation of IκBα and nuclear translocation of NF-κB, compared with findings in neutrophil cultures that contained LPS without AICAR or barberine. Administration of AICAR to mice resulted in activation of AMPK in the lungs and was associated with decreased severity of LPS-induced lung injury, as determined by diminished neutrophil accumulation in the lungs, reduced interstitial pulmonary edema, and diminished levels of TNF-α and IL-6 in bronchoalveolar lavage fluid. These results suggest that AMPK activation reduces TLR4-induced neutrophil activation and diminishes the severity of neutrophil-driven proinflammatory processes, including acute lung injury.


2020 ◽  
Vol 19 (7) ◽  
pp. 1429-1433
Author(s):  
Jihong Shu ◽  
Zhenjiao Fang ◽  
Xinjun Xiong

Purpose: To investigate the effect of penehyclidine hydrochloride (PHC) on interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), hypoxia inducible factor-1α (HIF-1α), and oxidative stress levels in lung tissues of acute lung injury (ALI) neonatal rats.Methods: 40 male Sprague-Dawley (SD) rats were assigned to model, low-dose PHC, high-dose PHC, and control groups (n = 10). Levels of IL-6, TNF-α and HIF-1α were evaluated by enzyme-linked immunosorbent assay (ELISA). Pulmonary lesions were determined histologically using H&E staining.Results: The lung tissue levels of IL-6, TNF-α and HIF-1α were significantly higher in model rats than in control rats, and significantly lower in PHC-treated rats than in model group, with decrease in levels as PHC dose increased (p < 0.05). The lung tissue activity of MPO and level of MDA in model rats were significantly higher than those in control rats, but significantly lower in the lung tissues of the two PHC groups than in the model group; decrease in levels occurred as PHC dose increased (p < 0.05).Conclusion: PHC decreases the lung and serum levels of IL-6, TNF-α and HIF-1α in a rat model of ALI, and mitigates pulmonary oxidative stress and lung tissue damage. Thus, penehyclidine hydrochloride may be useful to mitigate ALI-induced damage in patients. However, further studies and clinical trials are required to ascertain this Keywords: Penehyclidine hydrochloride, Alveolar septum, Acute lung injury, Inflammatory cells, IL-6, TNF-α, HIF-1α, Oxidative stress


2005 ◽  
Vol 288 (5) ◽  
pp. L958-L965 ◽  
Author(s):  
Jae Yeol Kim ◽  
Jong Sung Park ◽  
Derek Strassheim ◽  
Ivor Douglas ◽  
Fernando Diaz del Valle ◽  
...  

High mobility group box 1 (HMGB1) is a novel late mediator of inflammatory responses that contributes to endotoxin-induced acute lung injury and sepsis-associated lethality. Although acute lung injury is a frequent complication of severe blood loss, the contribution of HMGB1 to organ system dysfunction in this setting has not been investigated. In this study, HMGB1 was detected in pulmonary endothelial cells and macrophages under baseline conditions. After hemorrhage, in addition to positively staining endothelial cells and macrophages, neutrophils expressing HMGB1 were present in the lungs. HMGB1 expression in the lung was found to be increased within 4 h of hemorrhage and then remained elevated for more than 72 h after blood loss. Neutrophils appeared to contribute to the increase in posthemorrhage pulmonary HMGB1 expression since no change in lung HMGB1 levels was found after hemorrhage in mice made neutropenic with cyclophosphamide. Plasma concentrations of HMGB1 also increased after hemorrhage. Blockade of HMGB1 by administration of anti-HMGB1 antibodies prevented hemorrhage-induced increases in nuclear translocation of NF-κB in the lungs and pulmonary levels of proinflammatory cytokines, including keratinocyte-derived chemokine, IL-6, and IL-1β. Similarly, both the accumulation of neutrophils in the lung as well as enhanced lung permeability were reduced when anti-HMGB1 antibodies were injected after hemorrhage. These results demonstrate that hemorrhage results in increased HMGB1 expression in the lungs, primarily through neutrophil sources, and that HMGB1 participates in hemorrhage-induced acute lung injury.


2014 ◽  
Vol 307 (10) ◽  
pp. L735-L745 ◽  
Author(s):  
Dae Won Park ◽  
Shaoning Jiang ◽  
Yanping Liu ◽  
Gene P. Siegal ◽  
Ken Inoki ◽  
...  

Although AMP-activated protein kinase (AMPK) is involved in regulating carbohydrate and lipid metabolism, activated AMPK also plays an anti-inflammatory role in many cell populations. However, despite the ability of AMPK activation to diminish the severity of inflammatory responses, previous studies have found that AMPK activity is diminished in LPS-treated neutrophils and also in lungs of mice with LPS-induced acute lung injury (ALI). Since GSK3β participates in regulating AMPK activity, we examined potential roles for GSK3β in modulating LPS-induced activation of neutrophils and macrophages and in influencing severity of ALI. We found that GSK3β-dependent phosphorylation of T479-AMPK was associated with pT172 dephosphorylation and inactivation of AMPK following TLR4 engagement. GSK3β inhibitors BIO (6-bromoindirubin-3′-oxime), SB216763 , or siRNA knockdown of GSK3β, but not the PI3K/AKT inhibitor LY294002, prevented Thr172-AMPK dephosphorylation. Exposure to LPS resulted in rapid binding between IKKβ and AMPKα, and phosphorylation of S485-AMPK by IKKβ. These results suggest that IKKβ-dependent phosphorylation of S485-AMPK was an essential step in subsequent phosphorylation and inactivation AMPK by GSK3β. Inhibition of GSK3β activity delayed IκBα degradation and diminished expression of the proinflammatory TNF-α in LPS-stimulated neutrophils and macrophages. In vivo, inhibition of GSK3β decreased the severity of LPS-induced lung injury as assessed by development of pulmonary edema, production of TNF-α and MIP-2, and release of the alarmins HMGB1 and histone 3 in the lungs. These results show that inhibition of AMPK by GSK3β plays an important contributory role in enhancing LPS-induced inflammatory responses, including worsening the severity of ALI.


2021 ◽  
Vol 19 (12) ◽  
pp. 2559-2563
Author(s):  
Hongcheng Zang ◽  
Gang Shao

Purpose: To investigate the effect of dexmedetomidine in a rat model of acute lung injury (ALI), and the underlying mechanism. Methods: Acute lung injury (ALI) was induced in adult male Sprague Dawley rats (n = 27) using lipopolysaccharide (LPS). Three rat groups were used (9 rats/group): untreated control, LPS and treatment groups. Pathological lesions in rat pulmonary tissues were assessed and inflammatory scores determined. The levels TNF-α and IL-6 in BALF were determined using their respective enzyme-linked immunosorbent assay (ELISA) kits, while protein levels of p-IκB and NF-κB p65 were assessed by Western blotting. Results: Lung tissue damage was markedly mitigated in treatment mice, relative to LPS mice (p < 0.05). Inflammatory scores and population of neutrophils and macrophages increased significantly in LPS mice, relative to control, but decreased by dexmedetomidine exposure (p < 0.05). Similarly, TNF-α and IL-6 levels in pulmonary tissue homogenates of LPS rats were increased, relative to control rats, but were downregulated by dexmedetomidine exposure (p < 0.05). Moreover, dexmedetomidine downregulated the expressions of p-IκB and NF-κB p65 in pulmonary tissues (p < 0.05). Conclusion: Dexmedetomidine mitigates LPS-induced ALI in rats by blocking the activation of NF-κB and IκB, coupled with inhibition of the secretion of TNF-α and IL-6. Keywords: Acute lung injury, Dexmedetomidine, Inflammatory cytokines, NF-κB pathway, Sepsis


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