scholarly journals LincRNA-Cox2 functions to regulate inflammation in alveolar macrophages during acute lung injury.

2021 ◽  
Author(s):  
Elektra K Robinson ◽  
Atesh K Worthington ◽  
Donna M Poscablo ◽  
Barbara Shapleigh ◽  
May Mohammed Salih ◽  
...  

The respiratory system exists at the interface between our body and the surrounding non-sterile environment; therefore, it is critical for a state of homeostasis to be maintained through a balance of pro- and anti- inflammatory cues. An appropriate inflammatory response is vital for combating pathogens, while an excessive or uncontrolled inflammatory response can lead to the development of chronic diseases. Recent studies show that actively transcribed noncoding regions of the genome are emerging as key regulators of biological processes, including inflammation. LincRNA-Cox2 is one such example of an inflammatory inducible long noncoding RNA functioning to control immune response genes. Here using bulk and single cell RNA-seq, in addition to florescence activated cell sorting, we show that lincRNA-Cox2 is most highly expressed in the lung, particularly in alveolar macrophages where it functions to control immune gene expression following acute lung injury. Utilizing a newly generated lincRNA-Cox2 transgenic overexpressing mouse, we show that it can function in trans to control genes including Ccl3, 4 and 5. This work greatly expands our understanding of the role for lincRNA-Cox2 in host defense and sets in place a new layer of regulation in RNA-immune-regulation of genes within the lung.

2021 ◽  
Author(s):  
Gaojian Wang ◽  
Yaping Zhang ◽  
Nianqiang Hu ◽  
Qinxue Liu ◽  
Fengjie Ma ◽  
...  

Abstract Background: Mesenchymal stem cell have shown therapeutic effect on acute lung injury, MSC could be activated when added to inflammatory environment and in turn suppress inflammation, yet the mechanism is complex and not understood. Methods: To determine the effect of MSC on ALI and alveolar macrophage activation, MSCs were administered to ALI mice and co-cultured with activated MH-S cells (alveolar macrophage cell line). To find the genes critical for MSC’s immunosuppressive effects, rest and activated MSCs induced by inflammatory MH-S cells were harvested for RNA-seq. To prove that PGE2 participates in the immunosuppressive effects of MSC, COX2 inhibitor and PGE2 receptor antagonist were added to the co-culture system and administrated to ALI mice. Results: The intratracheal administration of MSCs attenuated ALI and suppressed alveolar macrophages activation in vivo, the activation of MH-S cells was also significantly reduced after co-culturing with MSCs in vitro. The RNA-seq data of rest and activated MSCs suggested that the Ptgs2 gene may play an important role in MSC exerting immunosuppressive effects. Correspondingly, we found that the COX2 protein and PGE2 released by activated MSCs were increased dramatically after co-culturing with MH-S. The use of COX2 inhibitor NS-398 restrained the secretion of PGE2 and reversed the suppressive effect on macrophages activation of MSCs in vitro. Furthermore, GW627368X, a selective antagonist of PGE2 receptor (EP4 receptor), also reversed the inhibitory effects of MSCs on alveolar macrophages and their protective effects on ALI mice.Conclusions: MSC attenuate ALI partly through suppressing alveolar macrophage activation via PGE2 binding to EP4 receptor.


2017 ◽  
Vol 117 (11) ◽  
pp. 2125-2134 ◽  
Author(s):  
Laura Chimenti ◽  
Marta Camprubí-Rimblas ◽  
Raquel Guillamat-Prats ◽  
Maria Gomez ◽  
Jessica Tijero ◽  
...  

Objective Alveolar macrophages play a key role in the development and resolution of acute respiratory distress syndrome (ARDS), modulating the inflammatory response and the coagulation cascade in lungs. Anti-coagulants may be helpful in the treatment of ARDS. This study investigated the effects of nebulized heparin on the role of alveolar macrophages in limiting lung coagulation and inflammatory response in an animal model of acute lung injury (ALI). Methods Rats were randomized to four experimental groups. In three groups, ALI was induced by intratracheal instillation of lipopolysaccharide (LPS) and heparin was nebulized at constant oxygen flow: the LPS/Hep group received nebulized heparin 4 and 8 hours after injury; the Hep/LPS/Hep group received nebulized heparin 30 minutes before and 4 and 8 hours after LPS-induced injury; the LPS/Sal group received nebulized saline 4 and 8 hours after injury. The control group received only saline. Animals were exsanguinated 24 hours after LPS instillation. Lung tissue, bronchoalveolar lavage fluid (BALF) and alveolar macrophages isolated from BALF were analysed. Results LPS increased protein concentration, oedema and neutrophils in BALF as well as procoagulant and proinflammatory mediators in lung tissue and alveolar macrophages. In lung tissue, nebulized heparin attenuated ALI through decreasing procoagulant (tissue factor, thrombin–anti-thrombin complexes, fibrin degradation products) and proinflammatory (interleukin 6, tumour necrosis factor alpha) pathways. In alveolar macrophages, nebulized heparin reduced expression of procoagulant genes and the effectors of transforming growth factor beta (Smad 2, Smad 3) and nuclear factor kappa B (p-selectin, CCL-2). Pre-treatment resulted in more pronounced attenuation. Conclusion Nebulized heparin reduced pulmonary coagulopathy and inflammation without producing systemic bleeding, partly by modulating alveolar macrophages.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Huahe Zhu ◽  
Shun Wang ◽  
Cong Shan ◽  
Xiaoqian Li ◽  
Bo Tan ◽  
...  

AbstractXuan-bai-cheng-qi decoction (XCD), a traditional Chinese medicine (TCM) prescription, has been widely used to treat a variety of respiratory diseases in China, especially to seriously infectious diseases such as acute lung injury (ALI). Due to the complexity of the chemical constituent, however, the underlying pharmacological mechanism of action of XCD is still unclear. To explore its protective mechanism on ALI, firstly, a network pharmacology experiment was conducted to construct a component-target network of XCD, which identified 46 active components and 280 predicted target genes. Then, RNA sequencing (RNA-seq) was used to screen differentially expressed genes (DEGs) between ALI model rats treated with and without XCD and 753 DEGs were found. By overlapping the target genes identified using network pharmacology and DEGs using RNA-seq, and subsequent protein–protein interaction (PPI) network analysis, 6 kernel targets such as vascular epidermal growth factor (VEGF), mammalian target of rapamycin (mTOR), AKT1, hypoxia-inducible factor-1α (HIF-1α), and phosphoinositide 3-kinase (PI3K) and gene of phosphate and tension homology deleted on chromsome ten (PTEN) were screened out to be closely relevant to ALI treatment. Verification experiments in the LPS-induced ALI model rats showed that XCD could alleviate lung tissue pathological injury through attenuating proinflammatory cytokines release such as tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β. Meanwhile, both the mRNA and protein expression levels of PI3K, mTOR, HIF-1α, and VEGF in the lung tissues were down-regulated with XCD treatment. Therefore, the regulations of XCD on PI3K/mTOR/HIF-1α/VEGF signaling pathway was probably a crucial mechanism involved in the protective mechanism of XCD on ALI treatment.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qingsong Sun ◽  
Man Luo ◽  
Zhiwei Gao ◽  
Xiang Han ◽  
Weiqin Wu ◽  
...  

Abstract Background Acute lung injury (ALI) is a pulmonary disorder that leads to acute respiration failure and thereby results in a high mortality worldwide. Increasing studies have indicated that toll-like receptor 4 (TLR4) is a promoter in ALI, and we aimed to explore the underlying upstream mechanism of TLR4 in ALI. Methods We used lipopolysaccharide (LPS) to induce an acute inflammatory response in vitro model and a murine mouse model. A wide range of experiments including reverse transcription quantitative polymerase chain reaction, western blot, enzyme linked immunosorbent assay, flow cytometry, hematoxylin–eosin staining, RNA immunoprecipitation, luciferase activity and caspase-3 activity detection assays were conducted to figure out the expression status, specific role and potential upstream mechanism of TLR4 in ALI. Result TLR4 expression was upregulated in ALI mice and LPS-treated primary bronchial/tracheal epithelial cells. Moreover, miR-26a-5p was confirmed to target TLR4 according to results of luciferase reporter assay. In addition, miR-26a-5p overexpression decreased the contents of proinflammatory factors and inhibited cell apoptosis, while upregulation of TLR4 reversed these effects of miR-26a-5p mimics, implying that miR-26a-5p alleviated ALI by regulating TLR4. Afterwards, OPA interacting protein 5 antisense RNA 1 (OIP5-AS1) was identified to bind with miR-26a-5p. Functionally, OIP5-AS1 upregulation promoted the inflammation and miR-26a-5p overexpression counteracted the influence of OIP5-AS1 upregulation on cell inflammatory response and apoptosis. Conclusion OIP5-AS1 promotes ALI by regulating the miR-26a-5p/TLR4 axis in ALI mice and LPS-treated cells, which indicates a promising insight into diagnostics and therapeutics in ALI.


2005 ◽  
Vol 31 (3) ◽  
pp. 307-321 ◽  
Author(s):  
Yoshizumi Takemura ◽  
Yoshinobu Iwasaki ◽  
Kazuhiro Nagata ◽  
Ichiro Yokomura ◽  
Sou Tando ◽  
...  

2020 ◽  
Author(s):  
Hongxia Mei ◽  
Ying Tao ◽  
Tianhao Zhang ◽  
Feng Qi

Abstract Background: Acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS) are critical life-threatening syndromes characterized by the infiltration of a large number of neutrophils that lead to an excessive inflammatory response. Emodin (Emo) is a naturally occurring anthraquinone derivative and an active ingredient of Chinese medicine. It is believed to have anti-inflammatory effects. In this study, we examined the impact of Emo on the pulmonary inflammatory response and the neutrophil function in a rat model of lipopolysaccharide (LPS)-induced ALI.Results: Treatment with Emo protected rat against LPS-induced ALI. Compared to untreated rat, Emo-treated rat exhibited significantly ameliorated lung pathological changes and decreased tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). However, Emo has no protective effect on the rat model of acute lung injury with neutrophil deficiency. In addition, treatment with Emo enhanced the bactericidal capacity of LPS-induced neutrophils via the up-regulation of the ability of neutrophils to phagocytize bacteria and generate neutrophil extracellular traps (NETs). Emo also downregulated the neutrophil respiratory burst and the expression of reactive oxygen species (ROS) in LPS-stimulated neutrophils, alleviating the damage of neutrophils to surrounding tissues. Finally, Emo can accelerate the resolution of inflammation by promoting apoptosis of neutrophils. Conclusion: Our results provide the evidence that Emo could ameliorates LPS-induced ALI via its anti-inflammatory action by modulating the function of neutrophils. Emo may be a promising preventive and therapeutic agent in the treatment of ALI.


2021 ◽  
Author(s):  
Liang Qiao ◽  
Rongxia Li ◽  
Shangang Hu ◽  
Yu Liu ◽  
Hongqiang Liu ◽  
...  

Abstract Objective Previously, the protective effect of microRNA (miR)-145-5p has been discovered in acute lung injury (ALI). Thus, this study attempts to further discuss the mechanism of miR-145-5p in ALI through the downstream E26 transformation-specific proto-oncogene 2 (ETS2)/transforming growth factor β1 (TGF-β1)/Smad pathway. Methods A lipopolysaccharide (LPS)-induced rat ALI model was established. Recombinant adenovirus miR-145-5p and/or ETS2 overexpression plasmid was administrated into rats. Afterwards, pathological damage in the lung tissue, wet/dry (W/D) ratio, apoptosis and contents of serum inflammatory factors were observed. miR-145-5p, ETS2, TGF-β1, Smad2/3, phosphorylated Smad2/3 levels were measured in rats. Results miR-145-5p was down-regulated, ETS2 was up-regulated and TGF-β1/Smad pathway was activated in LPS-suffered rats. Overexpression of miR-145-5p inactivated the TGF-β1/Smad pathway and attenuated ALI, as reflected by relived pathological damage, and decreased W/D ratio, apoptosis and inflammatory response. Oppositely, loss of miR-145-5p or enhancement of ETS2 worsened ALI and activated the TGF-β1/Smad pathway. Moreover, elevation of ETS2 decreased miR-145-5p-mediated protection against ALI. Conclusion Evidently, miR-145-5p negatively regulates ETS2 expression and inactivates TGF-β1/Smad pathway to ameliorate ALI in rats.


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.


Sign in / Sign up

Export Citation Format

Share Document