scholarly journals Emodin Attenuates LPS-Induced Acute Lung Injury by Inhibiting NLRP3 Inflammasome-Dependent Pyroptosis Signaling Pathway In vitro and In vivo

Inflammation ◽  
2021 ◽  
Author(s):  
Yuhan Liu ◽  
Luorui Shang ◽  
Jiabin Zhou ◽  
Guangtao Pan ◽  
Fangyuan Zhou ◽  
...  

Abstract—Emodin, the effective component of the traditional Chinese medicine Dahuang, has anti-inflammatory effects. However, the protective effects and potential mechanisms of emodin are not clear. This study investigated the protective effects and potential mechanisms of emodin on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in vitro and in vivo. In vivo, we designed an LPS-induced ALI rat model. In vitro, we chose the J774A.1 cell line to establish an inflammatory cellular model, and knocked down NOD-like receptor family pyrin domain containing 3 (NLRP3) using small interfering RNA. The mRNA and protein expression of NLRP3, a C-terminal caspase recruitment domain (ASC), caspase 1 (CASP1), and gasdermin D (GSDMD) in cells and lung tissues were detected by western blot and real-time quantitative polymerase chain reaction (PCR). The expression levels of interleukin 1 beta (IL-1β) and IL-18 in the serum and supernatant were determined by the enzyme-linked immunosorbent assay. The degree of pathological injury in lung tissue was evaluated by hematoxylin and eosin (H&E) staining. In vitro, we demonstrated that emodin could inhibit NLRP3 and then inhibit the expression of ASC, CASP1, GSDMD, IL-1β, and IL-18. In vivo, we confirmed that emodin had protective effects on LPS-induced ALI and inhibitory effects on NLRP3 inflammasome -dependent pyroptosis. Emodin showed excellent protective effects against LPS-induced ALI by regulating the NLRP3 inflammasome-dependent pyroptosis signaling pathway.

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Quanxin Ma ◽  
Kai Wang ◽  
Qinqin Yang ◽  
Shun Ping ◽  
Weichun Zhao ◽  
...  

Veronicastrum axillare is a traditional medical plant in China which is widely used in folk medicine due to its versatile biological activities, especially for its anti-inflammatory effects. However, the detailed mechanism underlying this action is not clear. Here, we studied the protective effects of V. axillare against acute lung injury (ALI), and we further explored the pharmacological mechanisms of this action. We found that pretreatment with V. axillare suppressed the release of proinflammatory cytokines in the serum of ALI mice. Histological analysis of lung tissue demonstrated that V. axillare inhibited LPS-induced lung injury, improved lung morphology, and reduced the activation of nuclear factor-κB (NF-κB) in the lungs. Furthermore, the anti-inflammatory actions of V. axillare were investigated in vitro. We observed that V. axillare suppressed the mRNA expression of interleukin-1β (IL-1β), IL-6, monocyte chemotactic protein-1 (MCP-1), cyclooxygenase-2 (COX-2), and tumor necrosis factor-α (TNF-α) in RAW264.7 cells challenged with LPS. Furthermore, pretreatment of V. axillare in vitro reduced the phosphorylation of p65 and IκB-α which is activated by LPS. In conclusion, our data firstly demonstrated that the anti-inflammatory effects of V. axillare against ALI were achieved through downregulation of the NF-κB signaling pathway, thereby reducing the production of inflammatory mediators.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yu-Qiong He ◽  
Can-Can Zhou ◽  
Jiu-Ling Deng ◽  
Liang Wang ◽  
Wan-Sheng Chen

Acute lung injury (ALI) is a common life-threatening lung disease, which is mostly associated with severe inflammatory responses and oxidative stress. Tanreqing injection (TRQ), a Chinese patent medicine, is clinically used for respiratory-related diseases. However, the effects and action mechanism of TRQ on ALI are still unclear. Recently, STING as a cytoplasmic DNA sensor has been found to be related to the progress of ALI. Here, we showed that TRQ significantly inhibited LPS-induced lung histological change, lung edema, and inflammatory cell infiltration. Moreover, TRQ markedly reduced inflammatory mediators release (TNF-α, IL-6, IL-1β, and IFN-β). Furthermore, TRQ also alleviated oxidative stress, manifested by increased SOD and GSH activities and decreased 4-HNE, MDA, LDH, and ROS activities. In addition, we further found that TRQ significantly prevented cGAS, STING, P-TBK, P-P65, P-IRF3, and P-IκBα expression in ALI mice. And we also confirmed that TRQ could inhibit mtDNA release and suppress signaling pathway mediated by STING in vitro. Importantly, the addition of STING agonist DMXAA dramatically abolished the protective effects of TRQ. Taken together, this study indicated that TRQ alleviated LPS-induced ALI and inhibited inflammatory responses and oxidative stress through STING signaling pathway.


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.


2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Tao Zhu ◽  
Changyi Li ◽  
Xue Zhang ◽  
Chunyan Ye ◽  
Shuo Tang ◽  
...  

The reduction of pulmonary surfactant (PS) is essential for decreased pulmonary compliance and edema in acute lung injury (ALI). Thyroid transcription factor-1 (TTF-1) plays a major role in the regulation of surfactant protein-A (SP-A), the most abundant protein component of PS. Simultaneously, the glucagon-like peptide-1 (GLP-1) analogue can enhance SP-A expression in the lung. However, the underlying mechanism is still unknown. The purpose of this study was to explore whether liraglutide, a GLP-1 analogue, upregulates SP-A expression through the TTF-1 signaling pathway in ALI. In vivo, a murine model of ALI was induced by lipopolysaccharide (LPS). Pulmonary inflammation, edema, insulin level, ultrastructural changes in type II alveolar epithelial (ATII) cells, and SP-A and TTF-1 expression were analyzed. In vitro, rat ATII cells were obtained. SP-A and TTF-1 expression in cells was measured. ShRNA-TTF-1 transfection was performed to knock down TTF-1 expression. Our data showed that LPS-induced lung injury and increase in insulin level, and LPS-induced reduction of SP-A and TTF-1 expression in both the lung and cells, were significantly compromised by liraglutide. Furthermore, we also found that these effects of liraglutide were markedly blunted by shRNA-TTF-1. Taken together, our findings suggest that liraglutide enhances SP-A expression in ATII cells and attenuates pulmonary inflammation in LPS-induced ALI, most likely through the TTF-1 signaling pathway.


2022 ◽  
Author(s):  
Zixuan Liu ◽  
Mingming Chen ◽  
Yini Sun ◽  
Xu Li ◽  
Liu Cao ◽  
...  

Heparin-binding protein (HBP), as a granule protein secreted by polymorphonuclear neutrophils (PMNs) participates in the pathophysiological process of sepsis. It has been reported that HBP is a biomarker of sepsis, which is related to the severity of septic shock and organ dysfunction. HBP binds to vascular endothelial cells as one of the primary target sites. However, it is still unclear whether HBP-binding protein receptors exist on the surface of ECs. The effect of HBP on vascular permeability in sepsis and its mechanism needs to be explored. We conducted in vivo and in vitro study. We demonstrated that HBP bound to transforming growth factor-β receptor type 2 (TGF-β-R2) as a ligand. GST pull-down analysis reveals that HBP mainly interacts with the extracellular domain of TGF-β-R2. HBP induced acute lung injury (ALI) and vascular leakage via activation of TGF-β/SMAD2/3 signaling pathway. Permeability assay suggests TGF-β-R2 is necessary for HBP-induced increased permeability. We also defined the role of HBP and its potential membrane receptor TGF-β-R2 in the blood-gas barrier in the pathogenesis of HBP-related ALI.


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.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xiyue Zhang ◽  
Li Du ◽  
Jinrong Zhang ◽  
Chunyan Li ◽  
Jie Zhang ◽  
...  

Acute lung injury (ALI) is a respiratory disease that leads to death in severe cases. Hordenine (Hor), a barley-derived natural product, has various biological activities, including anti-inflammatory, and anti-oxidation activities. We investigated the effect of Hor on lipopolysaccharide-induced ALI and its potential mechanism. The anti-inflammatory effects of Hor were detected using in vivo and in vitro models by enzyme-linked immunosorbent assay, real-time polymerase chain reaction, western blotting, and molecular docking simulations. Hor inhibited increases in the levels of inflammatory factors both in vivo and in vitro, and its anti-inflammatory effect inhibited activation of protein kinase B, nuclear factor-κB, and mitogen-activated protein kinase signaling. Hor alleviated lipopolysaccharide-induced ALI by inhibiting inflammatory cytokine increases in vivo and in vitro and shows potential for preventing inflammatory disease.


2021 ◽  
Author(s):  
Haijin Lv ◽  
Xiaofeng Yuan ◽  
Jiebin Zhang ◽  
Tongyu Lu ◽  
Jia Yao ◽  
...  

Abstract Objectives: Acute lung injury (ALI) remains one of the common causes of morbidity and mortality worldwide, so far, without any effective therapeutic approach. Previous researches have revealed that topical administration of umbilical cord-derived mesenchymal stem cells (UC-MSCs) can attenuate pathological changes in experimental acute lung injury. Heat shock (HS) pretreatment has been identified as a method to enhance survival and function of cells. The present study aimed to assess whether HS-pretreated mesenchymal stem cells (MSCs) could strengthen the immunomodulation and recovery from ALI. Materials and Methods: HS pretreatment was defined 42℃ for 1h, the changes of biological characteristics and the secreted functions were detected. In the mouse model of ALI, we intranasally dripped the pretreated UC-MSCs in vivo, confirmed their therapeutic effects and detected the phenotypes of macrophages in bronchoalveolar lavage fluid (BALF). To elucidate their mechanisms, we co-cultured the pretreated UC-MSCs with macrophages in vitro, and the expression levels of inflammasome-related proteins in macrophages were assessed. Finally, Apoptozole was used for further determine the role of HSP70 in HS-pretreated UC-MSCs-based therapy. Results: The data showed that UC-MSCs did not represented significant changes in viability and biological characterizations after received HS pretreatment. Administration of HS-pretreated UC-MSCs into the ALI model, improved pathological changes and lung damage-related indexes, reduced of the levels of pro-inflammatory cytokines and modulated the balance of M1/M2. Mechanistically, both in vivo and in vitro studies demonstrated that HS pretreatment enhanced the protein level of HSP70 in UC-MSCs and subsequently upregulated the synthesis and secretion of PGE2, which negatively modulated the NLRP3 inflammasome activation of alveolar macrophages. And these effects was partially reversed by Apoptozole. Conclusion: HS pretreatment can strengthen the beneficial effects of UC-MSCs on inhibiting NLRP3 inflammasome activation of macrophages in ALI. The mechanism may be contributed to the upregulated expression of HSP70 to further induce PGE2 synthesis and secretion.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jiali Song ◽  
Daoxing Chen ◽  
Yingqiao Pan ◽  
Xueqin Shi ◽  
Qian Liu ◽  
...  

Myeloid differentiation factor 88 (MyD88) is a hub protein in the Toll-like receptor signaling pathway, which acts as a master switch for numerous inflammatory diseases, including acute lung injury (ALI). Although this protein is considered as a crucial therapeutic target, there are currently no clinically approved MyD88-targeting drugs. Based on previous literature, here we report the discovery via computer-aided drug design (CADD) of a small molecule, M20, which functions as a novel MyD88 inhibitor to efficiently relieve lipopolysaccharide-induced inflammation both in vitro and in vivo. Computational chemistry, surface plasmon resonance detection (SPR) and biological experiments demonstrated that M20 forms an important interaction with the MyD88-Toll/interleukin-1 receptor domain and thereby inhibits the protein dimerization. Taken together, this study found a MyD88 inhibitor, M20, with a novel skeleton, which provides a crucial understanding in the development and modification of MyD88 inhibitors. Meanwhile, the favorable bioactivity of the hit compound is also conducive to the treatment of acute lung injury or other more inflammatory diseases.


Sign in / Sign up

Export Citation Format

Share Document