scholarly journals Downregulation of miR-497-5p Improves Sepsis-Induced Acute Lung Injury by Targeting IL2RB

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wei Lou ◽  
Jieping Yan ◽  
Weisi Wang

Introduction. Acute lung injury (ALI) induced by sepsis is a process related to inflammatory reactions, which involves lung cell apoptosis and production of inflammatory cytokine. Here, lipopolysaccharide (LPS) was applied to stimulate the mouse or human normal lung epithelial cell line (BEAS-2B) to construct a sepsis model in vivo and in vitro, and we also investigated the effect of miR-497-5p on sepsis-induced ALI. Material and Methods. Before LPS treatment, miR-497-5p antagomir was injected intravenously into mice to inhibit miR-497-5p expression in vivo. Similarly, miR-497-5p was knocked down in BEAS-2B cells. Luciferase reporter assay was applied to predict and confirm the miR-497-5p target gene. Cell viability, apoptosis, the levels of miR-497-5p, IL2RB, SP1, inflammatory cytokine, and lung injury were assessed. Results. In BEAS-2B cells, a significant increase of apoptosis and inflammatory cytokine was shown after LPS stimulation. In septic mice, increased inflammatory cytokine production and apoptosis in lung cells and pulmonary morphological abnormalities were shown. The miR-497-5p inhibitor transfection showed antiapoptotic and anti-inflammatory effects on BEAS-2B cells upon LPS stimulation. In septic mice, the miR-497-5p antagomir injection also alleviated ALI, apoptosis, and inflammation caused by sepsis. The downregulation of IL2RB in BEAS-2B cells reversed the protective effects of the miR-497-5p inhibitor against ALI. Conclusion. In conclusion, downregulation of miR-497-5p reduced ALI caused by sepsis through targeting IL2RB, indicating the potential effect of miR-497-5p for improving ALI caused by sepsis.

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098635
Author(s):  
Qi Gao ◽  
Ningqing Chang ◽  
Donglian Liu

Objectives To investigate the mechanisms underlying the protective effect of sufentanil against acute lung injury (ALI). Material and Methods Rats were administered lipopolysaccharide (LPS) by endotracheal instillation to establish a model of ALI. LPS was used to stimulate BEAS-2B cells. The targets and promoter activities of IκB were assessed using a luciferase reporter assay. Apoptosis of BEAS-2B cells was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling. Results Sufentanil treatment markedly reduced pathological changes in lung tissue, pulmonary edema and secretion of inflammatory factors associated with ALI in vivo and in vitro. In addition, sufentanil suppressed apoptosis induced by LPS and activated NF-κB both in vivo and in vitro. Furthermore, upregulation of high mobility group box protein 1 (HMGB1) protein levels and downregulation of miR-129-5p levels were observed in vivo and in vitro following sufentanil treatment. miR-129-5p targeted the 3ʹ untranslated region and its inhibition decreased promoter activities of IκB-α. miR-129-5p inhibition significantly weakened the protective effect of sufentanil on LPS-treated BEAS-2B cells. Conclusion Sufentanil regulated the miR-129-5p/HMGB1 axis to enhance IκB-α expression, suggesting that sufentanil represents a candidate drug for ALI protection and providing avenues for clinical treatment.


2021 ◽  
Vol 12 (10) ◽  
Author(s):  
Deqiang Luo ◽  
Wei Dai ◽  
Xiaojin Feng ◽  
Chengzhi Ding ◽  
Qiang Shao ◽  
...  

AbstractAcute lung injury (ALI) is a common lung pathology that is accompanied by alveolar macrophage (AM) activation and inflammatory response. This study investigated the role of the long non-coding RNA NONRATT004344 (hereafter named lncRNA NLRP3) in regulating the Nod-like receptor protein 3 (NLRP3)-triggered inflammatory response in early ALI and the underlying mechanism as well. We established LPS-induced ALI models to explore their interactive mechanisms in vitro and in vivo. Luciferase reporter assays were performed to determine that miR-138-5p could bind to lncRNA NLRP3 and NLRP3. We observed increased lncRNA NLRP3 expression, decreased miR-138-5p expression, NLRP3 inflammasome activation, and upregulated caspase-1, IL-1β, and IL-18 expression in the LPS-induced ALI model. Furthermore, lncRNA NLRP3 overexpression activated the NLRP3 inflammasome and promoted IL-1β and IL-18 secretion; the miR-138-5p mimic abolished these effects in vivo and in vitro. Consistently, miR-138-5p inhibition reversed the effects of lncRNA NLRP3 silencing on the expression of NLRP3-related molecules and inhibition of the NLRP3/caspase-1/IL-1β signalling pathway. Mechanistically, lncRNA NLRP3 sponging miR-138-5p facilitated NLRP3 activation through a competitive endogenous RNA (ceRNA) mechanism. In summary, our results suggested that lncRNA NLRP3 binding miR-138-5p promotes NLRP3-triggered inflammatory response via lncRNA NLRP3/miR-138-5p/NLRP3 ceRNA network (ceRNET) and provides insights into the treatment of early ALI.


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.


Author(s):  
Fen Liu ◽  
Wei Peng ◽  
Jiaquan Chen ◽  
Zeyao Xu ◽  
Rong Jiang ◽  
...  

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.


2021 ◽  
Author(s):  
yuhan liu ◽  
jiabin zhou ◽  
yingying luo ◽  
jinxiao li ◽  
luorui shang ◽  
...  

Abstract Background Honokiol (HKL) has been reported to ameliorate lipopolysaccharide (LPS)-induced acute lung injury (ALI). However, its potential mechanism imparting the protective effects remains unclear. In this study, the protective mechanism of HKL on LPS-induced ALI was explored in vivo and in vitro. Methods In vivo, the SD rats were intratracheally instilled with LPS (5 mg/kg) to establish an acute lung injury model and then treated with HKL (1.25/2.5/5 mg/kg) or ML385 (30 mg/kg) intraperitoneally. In vitro, the human bronchial epithelial cell line (BEAS-2B) was stimulated with LPS and ATP to induce pyroptosis and treated with HKL (12.5/25/50 µM). Small interfering RNA (siRNA) technique was used to knockdown Nrf2 in BEAS-2B cells. The protein and mRNA expression levels of Nrf2, HO-1, NLRP3, ASC, CASP1, and GSDMD in cells and lung tissues were detected by western blot and real time-PCR. The expression levels of interleukin (IL)-1β, IL-18, MPO, MDA, and SOD in bronchoalveolar lavage fluid (BALF) and supernatant were determined by ELISA. The degree of pathological injury of lung tissue was evaluated by H&E staining. Results The results showed that HKL could alleviate the oxidative stress and inflammatory responses by regulating the levels of MPO, MDA, SOD, IL-1β, IL-18 in supernatant. And HKL inhibited the expression levels of NLRP3, ASC, CASP1, GSDMD via activation of Nrf2 in BEAS-2B cells. Further studies revealed that HKL could attenuate the pathological injury in LPS-induced ALI rats and the molecular mechanism was consistent with the results in vitro. Conclusions Our study demonstrated that HKL could alleviate LPS-induced ALI by reducing the oxidative stress and inhibiting NLRP3 inflammasome-mediated pyroptosis, which was partly dependent on the Nrf2 activation.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mengqing Tao ◽  
Jia Jiang ◽  
Lin Wang ◽  
Yan Li ◽  
Qingcheng Mao ◽  
...  

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.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Yuhan Liu ◽  
Jiabin Zhou ◽  
Yingying Luo ◽  
Jinxiao Li ◽  
Luorui Shang ◽  
...  

Abstract Background Honokiol (HKL) has been reported to ameliorate lipopolysaccharide (LPS)-induced acute lung injury (ALI). However, its potential mechanism of its protective effects remains unclear. In this study, the protective mechanism of HKL on LPS-induced ALI was explored in vivo and in vitro. Methods In vivo, the SD rats were intratracheally instilled with LPS (5 mg/kg) to establish an acute lung injury model and then treated with HKL (1.25/2.5/5 mg/kg) or ML385 (30 mg/kg) intraperitoneally. In vitro, the human bronchial epithelial cell line (BEAS-2B) was stimulated with LPS and ATP to induce pyroptosis and treated with HKL (12.5/25/50 μM). Small interfering RNA (siRNA) technique was used to knockdown Nrf2 in BEAS-2B cells. The protein and mRNA expression levels of Nrf2, HO-1, NLRP3, ASC, CASP1, and GSDMD in cells and lung tissues were detected by western blot and real time-PCR. The expression levels of interleukin (IL)-1β, IL-18, MPO, MDA, and SOD in bronchoalveolar lavage fluid (BALF) and supernatant were determined by ELISA. The degree of pathological injury of lung tissue was evaluated by H&E staining. Results The results showed that HKL could alleviate oxidative stress and inflammatory responses by regulating the levels of MPO, MDA, SOD, IL-1β, IL-18 in supernatant. And it could also inhibit the expression levels of NLRP3, ASC, CASP1, GSDMD via activation of Nrf2 in BEAS-2B cells. Further studies revealed that HKL could attenuate the pathological injury in LPS-induced ALI rats, and the molecular mechanism was consistent with the results in vitro. Conclusions Our study demonstrated that HKL could alleviate LPS-induced ALI by reducing the oxidative stress and inhibiting NLRP3 inflammasome-mediated pyroptosis, which was partly dependent on the Nrf2 activation. Graphical Abstract


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.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Wan-li Jiang ◽  
Kao-chang Zhao ◽  
Wen Yuan ◽  
Fang Zhou ◽  
Heng-ya Song ◽  
...  

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.


2021 ◽  
Author(s):  
Wenjing Jia ◽  
Wenting Ding ◽  
Xinmiao Chen ◽  
Zhengwei Xu ◽  
Yeilin Tang ◽  
...  

Abstract Acute lung injury (ALI) characterized by a series of inflammatory reactions and served as the main cause of mortality in intensive care unit patients. Although great progress have been made in understanding the pathophysiology of ALI, there are no effective treatment in clinic. Recently, we have synthesized a selenium-containing compounds, which possess obvious anti-inflammatory activity. The aim of the present study is to evaluate the protective effects of the selenium-containing compound 34# in LPS-induced ALI in mice as well as its underlying mechanism. Compound 34# was found to inhibit LPS-induced macrophage inflammatory cytokine release. These effects were observed to be produced via suppression of the MAPKs/AP-1 pathway. Compound 34# was also noted to attenuate the LPS-induced lung inflammation in mice with ALI. The corresponding results suggested that compound 34# possesses remarkable protective effects on LPS-induced ALI. Furthermore, the MAPKs/AP-1 pathway may prove to be its the underlying mechanism. Accordingly, compound 34# may serve as a potential candidate for the prevention of ALI.


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