Ischemic Postconditioning Attenuates Myocardial Ischemia-Reperfusion-Induced Acute Lung Injury by Regulating Endoplasmic Reticulum Stress-Mediated Apoptosis

ABSTRACT Objective: To explore the effect of ischemic postconditioning on myocardial ischemia-reperfusion-induced acute lung injury (ALI). Methods: Forty adult male C57BL/6 mice were randomly divided into sham operation group (SO group), myocardial ischemia-reperfusion group (IR group), ischemic preconditioning group (IPRE group) and ischemic postconditioning group (IPOST group) (10 mice in each group). Anterior descending coronary artery was blocked for 60 min and then reperfused for 15 min to induce myocardial IR. For the IPRE group, 3 consecutive cycles of 5 min of occlusion and 5 minutes of reperfusion of the coronary arteries were performed before ischemia. For the IPOST group, 3 consecutive cycles of 5 min reperfusion and 5 minutes of occlusion of the coronary arteries were performed before reperfusion. Pathological changes of lung tissue, lung wet-to-dry (W/D) weight ratio, inflammatory factors, oxidative stress indicators, apoptosis of lung cells and endoplasmic reticulum stress (ERS) protein were used to evaluate lung injury. Results: After myocardial IR, lung injury worsened significantly, manifested by alveolar congestion, hemorrhage, structural destruction of alveolar septal thickening, and interstitial neutrophil infiltration. In addition, lung W/D ratio was increased, plasma inflammatory factors, including interleukin (IL)-6, tumor necrosis factor (TNF)-α, and IL-17A, were increased, malondialdehyde (MDA) activity of lung tissue was increased, and superoxide dismutase (SOD) activity was decreased after myocardial IR. It was accompanied by the increased protein expression levels of ERS-related protein glucose regulatory protein 78 (GRP78), CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), and caspase-12, and the increased apoptotic indices of lung tissues. Conclusion: IPOST can effectively improve myocardial IR-induced ALI by inhibiting ERS-induced apoptosis of alveolar epithelial cells.

Inhibitory effects of formononetin on lipopolysaccharide-induced apoptosis and inflammatory response in alveolar epithelial cells / 中国药房

OBJECTIVE To investigate the inhibitory effects of formononetin on lipopolysaccharide （LPS）-induced apoptosis and inflammatory response in alveolar epithelial cells through phosphoinositide 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway. METHODS Human lung cancer alveolar basal epithelial cells A549 were cultured in vitro and divided into control group （no intervention）， model group （1 μg/mL LPS）， different concentrations of formononetin groups （1 μg/mL LPS+6.25， 12.5， 25， 50 μmol/L formononetin）. The levels of inflammatory factors （interleukin-8， tumor necrosis factor-α） and cell viability were detected in each group. Another A549 cells were divided into control group， model group （1 μg/mL LPS）， LPS+25 group （1 μg/mL LPS+25 μmol/L formononetin）， inhibitor group （1 μg/mL LPS+20 μmol/L LY294002）， formononetin+inhibitor group （1 μg/mL LPS+25 μmol/L formononetin+20 μmol/L LY294002） and formononetin+activator group （1 μg/mL LPS+25 μmol/L formononetin+ 10 μmol/L SC79）. The secretion levels and mRNA expressions of inflammatory factors， cell apoptosis， and expressions of the key proteins of PI3K/Akt signaling pathway were detected in each group. RESULTS Compared with model group， the levels of inflammatory factors were decreased significantly after the intervention of 25 μmol/L of formononetin， and the cell viability was increased significantly （P＜0.05）. Compared with the control group， the secretion levels and mRNA expressions of inflammatory factors， apoptotic rate， and relative expressions of phosphorylated Akt and phosphorylated PI3K of the model group were increased significantly （P＜0.05）. Compared with the model group， the above indexes of the LPS+25 group and the inhibitor group were decreased significantly （P＜0.05）. Compared with the LPS+25 group， the above indicators of formononetin+inhibitor group were further decreased， while those of formononetin+activator group were increased significantly （P＜0.05）. CONCLUSIONS Formononetin can inhibit LPS-induced epithelial cell apoptosis and improve inflammatory response， and the mechanism may be related to the inhibition of the PI3K/Akt signaling pathway.

Influences of notoginsenoside R1 on the injury of alveolar epithelial cells infected by Klebsiella pneumoniae by regulating JAK2STAT3 signaling pathway / 中国热带医学

@#Abstract: Objective　To investigate the influences of notoginsenoside R1 (NGR1) on cell injury and Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) signaling pathway of alveolar epithelial cells infected by Klebsiella pneumoniae (Kp). Methods　A549 cells were grouped into five groups: control group (C group), infection group (Infect group), infection + low NGR1 group (Infect + L-NGR1 group), infection + high NGR1 group (Infect + H-NGR1 group), and infection+high NGR1+JAK2/STAT3 pathway inhibitor group (Infect+H-NGR1+SD-1029 group). Cell proliferation was measured using CCK8; ELISA kits were applied to detect the contents of interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interferon γ (IFN-γ) in the culture medium; flow cytometry was applied to detect apoptosis; RT-qPCR was applied to detect the expressions of JAK2/STAT3; Western blot was applied to detect JAK2/STAT3 pathway, autophagy protein microtubule-associated protein 1 light chain 3 (LC3), autophagy-relatedgene5 (Atg5), autophagy-related gene (Atg) 6 (Beclin-1), apoptosis protein B-cell lymphoma 2 (Bcl-2), Bcl-2-accociated protein (Bax), cysteinyl aspartate specific proteinase (cleaved-caspase-3) proteins expression. Results　Compared with the C group, the 72 h cell viability, the protein levels of Bcl-2, LC3-II/I, Atg5, Beclin-1, the mRNA relative expressions and protein phosphorylation levels of JAK2, STAT3 in the Infect group were obviously decreased (P<0.05); the contents of IL-1β, TNF-α, IFN-γ, apoptosis rate, the protein levels of Bax and cleaved-caspase-3 were obviously increased (P<0.05). Compared with Infect group, the 72 h cell viability, the protein levels of Bcl-2, LC3-II/I, Atg5, Beclin-1, the mRNA relative expressions and protein phosphorylation levels of JAK2, STAT3 in the Infect+L-NGR1 group and Infect+H-NGR1 group were obviously increased (P<0.05); the contents of IL-1β, TNF-α, IFN-γ, apoptosis rate, the protein levels of Bax and cleaved-Caspase-3 were obviously decreased (P<0.05). Compared with Infect+H-NGR1 group, the 72 h cell viability, the protein levels of Bcl-2, LC3-II/I, Atg5, Beclin-1, the protein phosphorylation levels of JAK2, STAT3 in the Infect+H-NGR1+SD-1029 group were obviously decreased (P<0.05), and the contents of IL-1β, TNF-α, IFN-γ, apoptosis rate, the protein levels of Bax and cleaved-caspase-3 were obviously increased (P<0.05). Conclusions NGR1 can activate the JAK2/STAT3 signaling pathway, promote autophagy of alveolar epithelial cells, and inhibit Kp-induced inflammatory injury and apoptosis of alveolar epithelial cells.

Electrotaxis of alveolar epithelial cells in direct-current electric fields / 中华创伤杂志(英文版)

PURPOSE@#This study aims to elucidate the electrotaxis response of alveolar epithelial cells (AECs) in direct-current electric fields (EFs), explore the impact of EFs on the cell fate of AECs, and lay the foundation for future exploitation of EFs for the treatment of acute lung injury.@*METHODS@#AECs were extracted from rat lung tissues using magnetic-activated cell sorting. To elucidate the electrotaxis responses of AECs, different voltages of EFs (0, 50, 100, and 200 mV/mm) were applied to two types of AECs, respectively. Cell migrations were recorded and trajectories were pooled to better demonstrate cellular activities through graphs. Cell directionality was calculated as the cosine value of the angle formed by the EF vector and cell migration. To further demonstrate the impact of EFs on the pulmonary tissue, the human bronchial epithelial cells transformed with Ad12-SV40 2B (BEAS-2B cells) were obtained and experimented under the same conditions as AECs. To determine the influence on cell fate, cells underwent electric stimulation were collected to perform Western blot analysis.@*RESULTS@#The successful separation and culturing of AECs were confirmed through immunofluorescence staining. Compared with the control, AECs in EFs demonstrated a significant directionality in a voltage-dependent way. In general, type Ⅰ alveolar epithelial cells migrated faster than type Ⅱ alveolar epithelial cells, and under EFs, these two types of cells exhibited different response threshold. For type Ⅱ alveolar epithelial cells, only EFs at 200 mV/mm resulted a significant difference to the velocity, whereas for, EFs at both 100 mV/mm and 200 mV/mm gave rise to a significant difference. Western blotting suggested that EFs led to an increased expression of a AKT and myeloid leukemia 1 and a decreased expression of Bcl-2-associated X protein and Bcl-2-like protein 11.@*CONCLUSION@#EFs could guide and accelerate the directional migration of AECs and exert antiapoptotic effects, which indicated that EFs are important biophysical signals in the re-epithelialization of alveolar epithelium in lung injury.

Swertiamarin attenuates paraquat-induced pulmonary epithelial-like cell apoptosis via NOX4-mediated regulation of redox and mitochondrial function

Abstract The aim of the present study was to investigate the effect of swertiamarin (STM) in attenuating paraquat (PQ)-induced human lung alveolar epithelial-like cell (A549) apoptosis and the underlying mechanisms. A549 cells were pretreated with different concentrations of STM for 2 hr and then cultured with or without PQ (700 µM) for 24 hr. Cell survival was determined using the CCK8 assay. Morphological changes, MDA content, inflammatory factors, fibrogenesis parameters, apoptosis rates, redox status and mitochondrial membrane potential (MMP) were evaluated. The expression of several genes involved in the modulation of redox status was measured by Western blotting. Cell viability and MMP were decreased, but the apoptosis rate and DCFH oxidation were elevated by PQ exposure. STM pretreatment notably increased cell viability and MMP and reduced the apoptosis rate and DCFH oxidation. Furthermore, TLR4- NOX4 signaling was significantly inhibited by STM. The downregulation of NOX4 by siRNA exerted the same protective effects as STM. This study provides the first evidence that STM attenuates PQ-induced pulmonary epithelial-like cell apoptosis via NOX4-mediated regulation of redox and mitochondrial function

Continuous purification and culture of rat type 1 and type 2 alveolar epithelial cells by magnetic cell sorting / 中华创伤杂志(英文版)

PURPOSE@#The incidence of acute lung injury (ALI) in severe trauma patients is 48% and the mortality rate following acute respiratory distress syndrome evolved from ALI is up to 68.5%. Alveolar epithelial type 1 cells (AEC1s) and type 2 cells (AEC2s) are the key cells in the repair of injured lungs as well as fetal lung development. Therefore, the purification and culture of AEC1s and AEC2s play an important role in the research of repair and regeneration of lung tissue.@*METHODS@#Sprague-Dawley rats (3-4 weeks, 120-150 g) were purchased for experiment. Dispase and DNase I were jointly used to digest lung tissue to obtain a single-cell suspension of whole lung cells, and then magnetic bead cell sorting was performed to isolate T1α positive cells as AEC1s from the single-cell suspension by using polyclonal rabbit anti-T1a (a specific AEC1s membrane protein) antibodies combined with anti-rabbit IgG microbeads. Afterwards, alveolar epithelial cell membrane marker protein EpCAM was designed as a key label to sort AEC2s from the remaining T1α-neg cells by another positive immunomagnetic selection using monoclonal mouse anti-EpCAM antibodies and anti-mouse IgG microbeads. Cell purity was identified by immunofluorescence staining and flow cytometry.@*RESULTS@#The purity of AEC1s and AEC2s was 88.3% ± 3.8% and 92.6% ± 2.7%, respectively. The cell growth was observed as follows: AEC1s stretched within the 12-16 h, but the cells proliferated slowly; while AEC2s began to stretch after 24 h and proliferated rapidly from the 2nd day and began to differentiate after 3 days.@*CONCLUSION@#AEC1s and AEC2s sorted by this method have high purity and good viability. Therefore, our method provides a new approach for the isolation and culture of AEC1s and AEC2s as well as a new strategy for the research of lung repair and regeneration.

Dynamic phenotype of lung type Ⅱ alveolar epithelial cells in radiation-induced lung injury and its role in the formation of fibrosis / 中华放射医学与防护杂志

Objective:To explore the dynamic phenotype of type Ⅱ alveolar epithelial cells(AEC Ⅱ)in radiation-induced lung fibrosisand its role in the formation of fibrosis.Methods:Totally 90 C57BL/6J female mice were divided into 2 groups: irradiation group (50, thoracic irradiation with a single dose of 20 Gy X-rays), control group (40, sham irradiation). At 24 h, 4 and 12 weeks after irradiation, 5 mice were euthanized and the lungs were collected for pathological observation. The other lungtissues were collected for the isolation of primary AEC Ⅱ cells with microbeadssorting.The mRNA expressions of proSP-C, HOPX, vimentin, β-catenin and TGF-β1 in AEC II cells were detected by RT-PCR.Results:Acute pneumonitis was observed in the lungs at 24 h after irradiation and alleviated in accompany with partial alveolar septal thickening and a small amount of collagen deposition at 4 weeks after irradiation. The collagen deposition became more pronounced at 12 weeks after irradiation, together with collapsed and fused alveolar cavities, alveolar septal hyperplasia, and pulmonary fibrosis formation.The mRNAexpression levels of proSP-C and HOPX in primary AEC Ⅱ cells increased at 24 hours after irradiation and then approached to a peak value at 4 weeks after irradiation ( F=8.441, 3.586, P=0.036). The mRNA expression levels of vimentin, a biomarker of EMT, was increased significantly at 4 weeks and continued up to 12 weeks after irradiation( F=8.358, P=0.001). The mRNA expression levels of profibrotic factors β-catenin and TGF-β1 were both significant increased at 12 weeks after irradiation( F=4.62, 3.279, P=0.044). Conclusions:The phenotypeof AECⅡ cells could not only be transformed from proSP-C+ to HOPX+ /proSP-C+ , HOPX+ /proSP-C+ /vimentin+ , and vimentin+ /proSP-C, but also differentiated into mesenchymal cells with highly expressed profibrotic factors, thereby inducing EMT process, which either played a role in the repair of radiation-induced lung injury or triggered radiation-induced fibrosis.

The role of polyomavirus enhancer activator 3 in hyperoxic-induced alveolar epithelial cells type Ⅱ injury / 中华实用儿科临床杂志

Objective:To investigate the role of polyomavirus enhancer activator 3 (PEA3) in hyperoxia-induced injury of type Ⅱ alveolar epithelial cells (AEC Ⅱ) and the underlying mechanism.Methods:AEC Ⅱ cells were cultured in vitro and divided into hyperoxia group and normoxia group.After 24 h, 48 h and 72 h of hyperoxia or air treatment, cells were collected and the best treatment time was selected at 48 h. AEC Ⅱ cells were divided into 3 groups: control group, negative control group (transfected with negative control) and PEA3 over expression group (transfected with PEA3 overexpression plasmid). Each group was further divided into hyperoxia subgroup and normoxia subgroup.Cells were harvested at 48 h after hyperoxia or normoxia treatment.Reactive oxygen species (ROS), Nod-like receptor domain 3 (NLRP3), monocyte chemoattractant protein-1 (MCP-1), interleukin(IL)-1β, IL-6, IL-8, IL-18, surfactant protein C (SP-C), aquaporins 5 (AQP5), PEA3 and manganese superoxide dismutase (MnSOD) levels were detected.Differences were compared by the t-test and repeated measures analysis of variance using SPSS 20.0 statistical software. Results:The interaction of grouping and treatment duration had significant effects on ROS, IL-1β, IL-6, IL-8, IL-18, SP-C and AQP5 levels in AEC Ⅱ cells ( F=19.857, 20.132, 23.133, 18.673, 28.341, 27.333 and 34.217, respectively, all P<0.05). At 24 h, 48 h and 72 h, ROS level in hyperoxia group was 1.78, 1.94 and 2.26 times higher than that in normoxia group ( t=18.649, 17.486 and 19.385, respectively all P<0.05). NLRP3 and MCP-1 levels were significantly upregulated in hyperoxia group.IL-1β level was 1.33, 1.69, and 1.65 times higher in hypoxia group at 24 h, 48 h and 72 h than that of normoxia group; IL-6 level was 1.26, 1.56 and 2.12 timers higher; IL-8 level was 1.13, 1.47 and 2.34 times higher; and IL-18 level was 1.46, 1.72 and 1.95 times higher, respectively (all P<0.05). The protein expression of SP-C was downregulated, while that of AQP5 was significantly upregulated in hypoxia group.The RNA expression of SP-C was 22%, 63% and 72% lower in hypoxia group than that in normoxia group at 24 h, 48 h and 72 h ( t=3.982, 16.328 and 20.259, P<0.05, respectively), and that of AQP5 was 1.92, 5.23 and 7.36 times higher ( t=14.631, 18.945 and 19.521, respectively, all P<0.05). There were significant differences in ROS, IL-1β, IL-6, IL-8, IL-18, SP-C and AQP5 levels at 24 h, 48 h and 72 h in hyperoxia group ( F=22.343, 20.566, 23.701, 19.222, 32.146, 40.278 and 37.107, respectively, all P<0.05). After 48 h of PEA3 overexpression, compared with the hyperoxic negative control group, ROS level in hyperoxic AEC Ⅱ cells overexpressing PEA3 decreased by 34% ( t=14.635, P<0.05). NLRP3 and MCP-1 were downregulated in hyperoxic AEC Ⅱ cells after overexpression of PEA3.IL-1β, IL-6, IL-8 and IL-18 levels decreased by 29%, 22%, 27% and 18%, respectively ( t=15.895, 17.872, 18.749 and 15.274, all P=0.000). SP-C was upre-gulated and AQP5 was downregulated by overexpression of PEA3 in hyperoxic AEC Ⅱ cells.In addition, PEA3 and MnSOD levels were significantly enhanced. Conclusions:Overexpression of PEA3 can alleviate the increase of ROS level in AEC Ⅱ cells, block the activation of various inflammatory pathways and reduce the transformation from AEC Ⅱ to AEC Ⅰ cells via enhancing MnSOD level.

Tea grape reduces abdominal aortic occlusion-induced lung injury

Abstract Introduction: Ischemia-associated mortality caused by aortic cross-clamps, as in ruptured abdominal aorta aneurysm surgeries, and reperfusion following their removal represent some of the main emergency conditions in cardiovascular surgery. The purpose of our study was to examine the potential protective effect of tea grape against aortic occlusion-induced lung injury using biochemical, histopathological, immunohistochemical, and quantitative analyses. Methods: Thirty-two male Sprague-Dawley rats were randomly assigned into four groups: control (healthy), glycerol + ischemia/reperfusion (I/R) (sham), I/R, and I/R + tea grape. Results: Following aortic occlusion, we observed apoptotic pneumocytes, thickening in the alveolar wall, edematous areas in interstitial regions, and vascular congestion. We also observed an increase in pulmonary malondialdehyde (MDA) levels and decrease in pulmonary glutathione (GSH). However, tea grape reduced apoptotic pneumocytes, edema, vascular congestion, and MDA levels, while increased GSH levels in lung tissue. Conclusion: Our findings suggest that tea grape is effective against aortic occlusion-induced lung injury by reducing oxidative stress and apoptosis.

Definición, patogenia y factores de riesgo de la fibrosis pulmonar idiopática / Definition, pathogenesis and risk factors of idiopathic pulmonary fibrosis

La fibrosis pulmonar idiopática (FPI) es una forma específica de neumonía intersticial idiopática, de tipo fibrosante crónica y progresiva, con patrón radiológico y/o histológico de neumonía intersticial usual (NIU). Su patogenia es compleja, el modelo más aceptado actualmente es basado en las células epiteliales alveolares, aberrantemente activadas que conducen a la proliferación de fibroblastos y su diferenciación a miofibroblastos que depositan matriz extracelular y destruyen irreversiblemente la arquitectura pulmonar. No existe un claro factor inicial que explique la activación y posterior mantención del mecanismo de la fibrosis. El factor de crecimiento transformante beta (TGF-β) liberado por las células epiteliales alveolares se ha implicado como unos de los principales conductores de la inducción y proliferación de fibroblastos alterados que persiste mucho tiempo después de la estimulación inicial, lo que explicaría en gran parte el comportamiento clínico progresivo y crónico.

Idiopathic pulmonary fibrosis (IPF) is a specific form of idiopathic interstitial pneumonia, of chronic and progressive fibrosing type, with radiological and / or histological pattern of usual interstitial pneumonia (UIP). Its pathogenesis is complex, the most accepted model currently is based on the fact that the alveolar epithelial cells, aberrantly activated, lead to the proliferation of fibroblasts and their differentiation to myofibroblasts that deposit extracellular matrix and irreversibly destroy the pulmonary architecture. There is no clear initial trigger that explains the activation and subsequent maintenance of the fibrosis mechanism. The transforming growth factor beta (TGF-β), released by the alveolar epithelial cells, has been implicated as one of the main drivers of the induction and proliferation of altered fibroblasts that persists long after the initial stimulation, which would largely explain progressive and chronic clinical behavior.

Bone marrow mesenchymal stem cells protect lungs from smoke inhalation injury by differentiating into alveolar epithelial cells via Notch signaling

To examine the protective effect of transplanting bone marrow mesenchymal stem cells (BMSCs) in treating lung injuryinduced by smoke exposure and to investigate the underlying mechanisms of this protection. SD rats were randomlydivided into four groups: normal group, normal ? BMSCGFP group, smoke group, and smoke ? BMSCGFP group. Todetect lung injury, we measured arterial blood gas, the wet-to-dry weight ratio, and levels of interleukin-1b, tumor necrosisfactor-a, interleukin-10, and interleukin-13 in bronchoalveolar lavage fluid and lung tissues. We also conductedhistopathology examinations. The protein markers of alveolar epithelial cells were measured to determine the BMSCdifferentiation. The protein levels of Notch1, Jagged-1, and Hes-1 also were detected. In the present study, BMSCtransplantation significantly decreased the wet-dry weight ratio of the lung, reduced the production of inflammatorymediators, and alleviated lung injury simply through differentiating into alveolar type II cells and alveolar type I cells.Western blot analysis confirmed that the protein expression of Notch-1, Jagged-1, and Hes-1 increased significantly aftersystemic BMSC transplantation. No significant difference was observed between the normal group and the normal ? BMSCGFP group. Our findings indicate that systemic transplantation of BMSCs alleviated lung injury induced bysmoke exposure, which may be associated with BMSCs’ ability to differentiate into alveolar-type cells via the Notchsignaling pathway.

Effects of diammonium glycyrrhizinate on Toll-like receptor 4 in alveolar epithelial cells induced by paraquat / 中华急诊医学杂志

Objective To investigate the effects of diammonium glycyrrhizinate (DG) on Toll-like receptor 4 in rat alveolar epithelial cells induced by paraquat (PQ).Methods Rats in the PR and PDR groups were induced 2 h by RU486 (100 nmol/L).Then rats in the DG and PDR groups were induced 2 h by DG (0.6 mg/mL).Finally,PQ (0.6 mg/mL) were administered and induced 24h in the PQ,DG,PR and PDR groups,while,the NE group was induced 24 h by absolute ethyl alcohol (0.33 μ mol/L),and the NS group was induced 24 h without drugs.MTT assay was used to measure the cell growth and inhibitioneffects of PQ and DG on cells.The ELISA assay was applied to measure the levels of the TLR-4,Myd88,NF-κB P65 and GR.The gene expressions ofTLR-4,Myd88,NF-κB P65 and GR were detected by RT-PCR.Results The survival rate of rat alveolar epithelial cells was decreased by PQ (200,400,600,800,1 000,1 500,2 000 μmol/L),and the IC50 value for 24 h was 927.045 μmol/L.The inhibition rates were (11.74±1.44)％,(18.76±1.30)％,(28.74±0.54)％,(40.30±0.55)％,(51.24±0.76)％,(68.19±1.10)％,(83.16±0.59)％ in the 200,400,600,800,1 000,1 500,2 000 pmol/L PQ treatment groups,respectively.And the inhibition rates were (48.01±1.37)％,(40.68±2.33)％,(32.76±4.11)％,(34.12±4.3)％,(39.22±2.23)％,(51.26±-0.39)％ in the 0.2,0.4,0.6,0.8,1,and 2 mg/mL DG treatment groups,respectively.The levels of TLR4,Myd88,NF-κB P65,and TNF-a in the PQ and PR groups were higher than those in the NS group (all P＜0.01).While,the levels of GR in the PQ and PR groups were lower than that in the NS group (all P＜0.01).And,the levels of TLR4,Myd88,NF-rκB P65,and TNF-α in the DG and PDR groups were lower than those in the PQ group (all P＜0.01).But the levels of GR in the DG and PDR groups were higher than that in the PQ group (all P＜0.01).Conclusions Diammonium Glycyrrhizinate can attenuate the injury of rat alveolar epithelial cells induced by paraquat,can decrease the levels of TLR-4,Myd88,NF-KB and TNF-α,and increase the GR level.

Bleomycin Inhibits Proliferation via Schlafen-Mediated Cell Cycle Arrest in Mouse Alveolar Epithelial Cells / 결핵

BACKGROUND: Idiopathic pulmonary fibrosis involves irreversible alveolar destruction. Although alveolar epithelial type II cells are key functional participants within the lung parenchyma, how epithelial cells are affected upon bleomycin (BLM) exposure remains unknown. In this study, we determined whether BLM could induce cell cycle arrest via regulation of Schlafen (SLFN) family genes, a group of cell cycle regulators known to mediate growth-inhibitory responses and apoptosis in alveolar epithelial type II cells. METHODS: Mouse AE II cell line MLE-12 were exposed to 1–10 µg/mL BLM and 0.01–100 µM baicalein (Bai), a G1/G2 cell cycle inhibitor, for 24 hours. Cell viability and levels of pro-inflammatory cytokines were analyzed by MTT and enzyme-linked immunosorbent assay, respectively. Apoptosis-related gene expression was evaluated by quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR). Cellular morphology was determined after DAPI and Hoechst 33258 staining. To verify cell cycle arrest, propidium iodide (PI) staining was performed for MLE-12 after exposure to BLM. RESULTS: BLM decreased the proliferation of MLE-12 cells. However, it significantly increased expression levels of interleukin 6, tumor necrosis factor α, and transforming growth factor β1. Based on Hoechst 33258 staining, BLM induced condensation of nuclear and fragmentation. Based on DAPI and PI staining, BLM significantly increased the size of nuclei and induced G2/M phase cell cycle arrest. Results of qRT-PCR analysis revealed that BLM increased mRNA levels of BAX but decreased those of Bcl2. In addition, BLM/Bai increased mRNA levels of p53, p21, SLFN1, 2, 4 of Schlafen family. CONCLUSION: BLM exposure affects pulmonary epithelial type II cells, resulting in decreased proliferation possibly through apoptotic and cell cycle arrest associated signaling.

Role and mechanism of nonreceptor tyrosine kinase Tec in endotoxin/lipopolysaccharide-induced interleukin-8 production in human alveolar epithelial cells A549 / 中华烧伤杂志

Objective@#To investigate the role and mechanism of nonreceptor tyrosine kinase Tec in the production of pro-inflammatory cytokine interleukin-8 (IL-8) induced by endotoxin/lipopolysaccharide (LPS) in human alveolar epithelial cells A549.@*Methods@#Human alveolar epithelial cells A549 were routinely cultured and passaged in Roswell Park Memorial Institute-1640 medium containing 10% fetal bovine serum. The second or third passage of cells were collected for subsequent experiments. (1) Cells were collected and divided into 6 groups with 4 wells in each group according to the random number table. Cells in blank control group were routinely cultured for 2 h. Cells in simple LPS group were routinely cultured for 1 h and then stimulated by 1 μg/mL LPS for 1 h. Cells in simple LFM-A13 group were cultured with conventional culture medium adding 75 μmol/L LFM-A13 for 1 h and then cultured with replaced conventional culture medium for 1 h. Cells in 25 μmol/L LFM-A13+ LPS group, 75 μmol/L LFM-A13+ LPS group, and 100 μmol/L LFM-A13+ LPS group were cultured with conventional culture medium adding 25, 75, and 100 μmol/L LFM-A13 respectively for 1 h and then all stimulated by 1 μg/mL LPS added into the replaced conventional culture medium for 1 h. The protein expression of Tec in cells of each group was detected by Western blotting, and the content of IL-8 in cell culture supernatant of each group was determined by enzyme-linked immunosorbent assay. (2) Cells were collected and divided into 5 groups with 4 wells in each group according to the random number table. Cells in blank control group were routinely cultured for 2 h. Cells in small interfering RNA (siRNA) control+ LPS group were transfected with empty lentivirus for 10 h and then stimulated by 1 μg/mL LPS added into the conventional culture medium for 2 h. Cells in Tec mus-298 RNA interference (RNAi)+ LPS group, Tec mus-299 RNAi+ LPS group, and Tec mus-300 RNAi+ LPS group were transfected with lentivirus loaded with Tec mus-298 RNAi, Tec mus-299 RNAi, and Tec mus-300 RNAi respectively for 10 h and then stimulated by 1 μg/mL LPS added into the conventional culture medium for 2 h. The protein expression of Tec in cells of each group was detected by Western blotting to screen Tec-siRNA with the best silencing effect on Tec gene. (3) Cells were collected and divided into 4 groups with 4 wells in each group according to the random number table. Cells in blank control group were routinely cultured for 2 h. Cells in virus control group were transfected with empty lentivirus for 10 h and then routinely cultured for 2 h. Cells in simple LPS group were stimulated by 1 μg/mL LPS added into the conventional culture medium for 2 h. Cells in Tec-siRNA+ LPS group were transfected with lentivirus loaded with Tec-siRNA with the best silencing effect on Tec gene for 10 h and then stimulated by 1 μg/mL LPS added into the conventional culture medium for 2 h. The protein expressions of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK) MAPK of cells in each group were detected by Western blotting. Data were processed with one-way analysis of variance and the least significant difference-t test.@*Results@#(1) Compared with that of blank control group, the protein expression of Tec of cells in simple LPS group was obviously increased (t=9.72, P<0.05), but the protein expression of Tec of cells in simple LFM-A13 group was not obviously changed (t=4.31, P=0.05). Compared with that of simple LPS group, the protein expression of Tec of cells in 25 μmol/L LFM-A13+ LPS group, 75 μmol/L LFM-A13+ LPS group, or 100 μmol/L LFM-A13+ LPS group was obviously decreased (t=9.72, 9.07, 16.33, P<0.05 or P<0.01). Compared with (189±22) pg/mL of blank control group, the content of IL-8 in culture supernatant of cells in simple LPS group was obviously increased [(214±10) pg/mL, t=2.18, P<0.05], but the content of IL-8 in culture supernatant of cells in simple LFM-A13 group was not obviously changed [(173±43) pg/mL, t=0.64, P>0.05]. Compared with that of simple LPS group, the content of IL-8 in culture supernatant of cells in 25 μmol/L LFM-A13+ LPS group was not obviously changed [(204±38) pg/mL, t=0.54, P>0.05], but the content of IL-8 in culture supernatant of cells in 75 μmol/L LFM-A13+ LPS group and 100 μmol/L LFM-A13+ LPS group was obviously decreased [(144±44), (137±51) pg/mL, t=3.63, 2.55, P<0.05 or P<0.01]. (2) Compared with that of blank control group, the protein expression of Tec of cells in siRNA control+ LPS group was obviously increased (t=14.24, P<0.01). Compared with that of siRNA control+ LPS group, the protein expression of Tec of cells in Tec mus-298 RNAi+ LPS group or Tec mus-299 RNAi+ LPS group was obviously decreased (t=36.03, 18.23, P<0.01), but the protein expression of Tec of cells in Tec mus-300 RNAi+ LPS group was not obviously changed (t=4.08, P>0.05). The protein expression of Tec was the lowest in cells of Tec mus-298 RNAi+ LPS group, so Tec mus-298 RNAi was used in subsequent experiment. (3) Compared with 1.16±0.16 and 0.78±0.11 of blank control group, the protein expressions of p38 MAPK and ERK MAPK of cells in virus control group were not obviously changed (1.66±0.13, 0.89±0.11, t=11.09, 3.60, P>0.05), but the protein expressions of p38 MAPK and ERK MAPK of cells in simple LPS group were obviously increased (2.83±0.29, 1.86±0.37, t=9.70, 7.23, P<0.05). Compared with those of simple LPS group, the protein expression of p38 MAPK and protein expression of ERK MAPK of cells in Tec-siRNA+ LPS group were obviously decreased (0.69±0.16, 1.03±0.24, t=13.78, 4.12, P<0.05 or P<0.01).@*Conclusions@#Tec may mediate the production and release of pro-inflammatory cytokine IL-8 from human alveolar epithelial cells A549 induced by LPS via the p38 MAPK and ERK MAPK signal pathways.

Olaparib regulates inflammatory response in lipopolysaccharide-induced A549 cells through PARP-1 pathway / 中国药理学与毒理学杂志

OBJECTIVE To investigate the protective effect of olaparib on the inflammatory damage to alveolar epithelial cells induced by lipopolysaccharide (LPS). METHODS The alveolar epithelial cells (A549) were cultured in vitro and incubated with LPS 10 mg-L-1 and olaparib 10 and 25 μmol-L-1 for 24 h. The levels of cytokines interleukin 6 (IL-6), IL-8, and IL-10 were detected by enzyme linked immunosorbent assay (ELISA), the mRNA expression levels of TNF-α, IL-1β, IL-6, IL-8, and ICAM-1 were analyzed by real-time PCR, the level of ROS was analyzed by flow cytometry, and the expression of poly (ADP-ribose) polymerase-1 (PARP-1) and phosphorylation of proteins involved in NF-ΚB signaling pathway in cells were detected by Western blotting. RESULTS Compared with LPS 10 mg-L-1 injury group, olaparib 10 and 25 μmol·L-1 could significantly reduce the release of IL-6, IL-8 and ROS levels in A549 cells induced by LPS (P<0.01), and increase the release of IL-10 (P<0.01). Olaparib 10 and 25 μmol·L-1 could also inhibit the mRNA expressions of TNF-α, IL-1β, IL-6, IL-8, and ICAM-1 (P<0.01), and inhibit the expression of PARP-1 and phosphorylation proteins involved in NF-ΚB signaling pathway induced by LPS (P<0.01). CONCLUSION Olaparib has some protective effect on inflammatory damage and oxidative stress in alveolar epithelial cells induced by LPS, and the mechanism may be that it inhibits the expression and release of cytokines by down-regulating the expression of PARP-1 and subsequently affecting the activation of the NF-ΚB pathway.

Effect of agmatine on apoptosis of type Ⅱ alveolar epithelial cells in rats with hyperoxia-induced acute lung injury / 中国中西医结合急救杂志

Objective To investigate the effects of agmatine (AGM) on the apoptosis of type Ⅱ alveolar epithelial cells (AECⅡ) in rats with hyperoxia-induced acute lung injury (HALI) and provide a theoretical basis for the treatment of HALI. Methods A total of 24 Sprague-Dawley (SD) rats were randomly divided into three groups:normal control group (fed in air), HALI model group and AGM pretreatment group (400 mg/kg AGM was given before the hyperoxia treatment or HALI model establishment), each group with 8 rats. The rats were placed in a self-made high oxygen model box with oxygen concentration of > 90%, temperature of 25-27 ℃, humidity of 50%-70% and carbon dioxide concentration < 0.5% to replicate the HALI rat model; no any treatment was given to the normal control group. After the hyperoxia was treated for 48 hours, the arterial blood was taken from the rat carotid artery for blood gas analysis;under light microscope, the pathological changes of lung tissues were observed and the pathological evaluation scores were carried out; the contents of tumor necrosis factor-α (TNF-α) and interleukins (IL-6, IL-1) in bronchoalveolar lavage fluid (BALF) were detected by enzyme-linked immunosorbent assay (ELISA); the apoptosis of AECⅡ of lung tissues was determined by flow cytometry, and the apoptotic rate was calculated; the expressions of the apoptosis related protein Bcl-2 and Bax were detected by Western Blot. Results Compared with the normal control group, the oxygenation index (OI) and Bcl-2 of HALI model group and AGM pretreatment group were significantly decreased [OI (mmHg, 1mmHg = 0.133 kPa): 135.04±16.82 vs. 463.74±22.04, Bcl-2 protein expression (A value): 0.35±0.18 vs. 0.89±0.08], while the respiratory index (RI), pathological scores of lung injury, TNF-α, IL-6, IL-1, the apoptosis rate of AECⅡ, Bax protein expression were all significantly increased [RI: 1.29±0.15 vs. 0.24±0.03, pathological score of lung tissue: 4.72±1.32 vs. 0, TNF-α (μg/L): 44.48±1.42 vs. 14.12±0.88, IL-6 (μg/L): 51.46±1.62 vs. 23.20±0.89, IL-1 (μg/L): 44.03±2.45 vs. 11.64±1.34, apoptosis rate of AECⅡ: (56.24±1.14)% vs. (22.64±0.58)%, Bax protein expression (A value): 2.37±0.34 vs. 1.41±0.48, all P < 0.05]. Compared with HALI model group, the OI and Bcl-2 of AGM pretreatment group were significantly increased [OI (mmHg): 364.72±14.56 vs. 135.04±16.82, Bcl-2 protein expression (A value): 0.68±0.10 vs. 0.35±0.18, all P < 0.05], while the RI, pathological scores of lung injury, TNF-α, IL-6, IL-1, apoptosis rate of AECⅡ, and Bax protein expression were significantly decreased [RI: 0.45±0.09 vs. 1.29±0.15, pathological score of lung tissue: 2.30±0.96 vs. 4.72±1.32, TNF-α (μg/L):22.98±0.72 vs. 44.48±1.42, IL-6 (μg/L): 35.79±0.86 vs. 51.46±1.62, IL-1 (μg/L): 24.06±0.86 vs. 44.03±2.45, apoptosis rate of AECⅡ: (28.58±1.21)% vs. (56.24±1.14)%, Bax protein expression (A value): 1.98±0.42 vs. 2.37±0.34, all P < 0.05]. Conclusion The apoptotic rate of AECⅡ in HALI rats is reduced by AGM, and the regulatory mechanism needs to be further studied.

The inflammatory effect of exosomes derived from alveolar epithelial cells stimulated by lipopolysaccharide on the alveolar macrophages / 中华急诊医学杂志

Objective To explore the inflammatory effect of exosomes derived from alveolar epithelial cells stimulated by lipopolysaccharide (LPS) on the alveolar macrophages (NR8383). Methods The alveolar epithelial cells disposed with different treatments were co-cultured with alveolar macrophages by using a Transwell system separately. Alveolar epithelial cells (RLE-6TN) were randomly divided into 4 groups: normal group, LPS-stimulated group, exosome inhibitor group, and exosome inhibitor pretreatment + LPS stimulation group. NR8383 cultured alone was considered as a blank control. After the 12-h co-culture, the real-time PCR (qPCR) was performed to examine the mRNA relative expression of IL-6, TNF-α, and IL-1β in NR8383 cells. To further explore the role of exosomes derived from RLE-6TN on alveolar macrophages mediated inflammationary response, the experimental exosomes (exosomes derived from LPS-induced RLE-6TN) and control exosomes exosomes derived from normal RLE-6TN were extracted by gradient ultracentrifugation. Transmission electron microscopy and Western blotting analyses was performed to identify the exosomes, and qNano particle diameter analyzer was conducted to measure the particle diameter of exosomes. In vitro, NR8383 cells were divided into 3 groups which were cultured with exosomes derived from LPS-stimulated RLE-6TN at a concentration of 10 μg/mL (experimental group), exosomes derived from untreated RLE-6TN at the same concentration of 10 μg/mL (control group), and the PBS at the same volume with experimental group (PBS group), respectively for 12 h. After the treatment, the phagocytosis of NR8383 cells was observed by laser confocal microscope and the release of interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α in supernatants of NR8383 was detected by enzyme-linked immunosorbent assay ELISA Results (1)In the co-culture experiment, the mRNA relative expression of pro-inflammatory cytokine in the LPS group was significantly increased compared with the blank control group (P<0.01), however comparing the exosome inhibitor pretreatment+LPS group with the LPS group, the expression of pro-inflammatory cytokine was decreased (P<0.01). (2) The extracted exosomes were observed as circular or elliptical vesicles with a diameter of 40-100 nm under the transmission electron microscopy. Western blotting analyses showed that the extracted exosomes express the protein marker, such as CD63 and CD9; After incubation with NR8383 cells for 5 h, laser scanning confocal microscope showed that the exosomes labeled with red fluorescent were uptaken by NR8383 cells. (3)After the exosomes derived from the LPS-disposed RLE-6TN and the normal RLE-6TN cells were incubated with NR8383 cells respectively. The ELISA test showed that treated the alveolar macrophages with LPS induced alveolar epithelial secreted exosomes led to a robustly increased release of pro-inflammatory cytokine (P<0.01), but there was no significant difference between the control group and PBS group (P>0.05). Conclusions Exosomes derived from LPS-disposed alveolar epithelial cells activate the alveolar macrophage-mediated inflammatory response.

The role of erlotinib in the acute lung injury and the expression of surfactant protein A / 中华急诊医学杂志

Objective To investigate the role of erlotinib in the expression of surfactant protein A (SP-A) in LPS-induced acute lung injury (ALI) of mice model.Methods C57BL/6 mice were randomly (random number)divided into control group (n=6),ER group (n=6),LPS group (n=6),and ER+LPS group (n=6).In the LPS group,2 mg/kg LPS was instilled into trachea of mice to induce lung injury.In control group,normal saline was instilled into trachea of mice instead.In the ER+LPS group and ER group,100 mg/kg of edotinib was instilled into stomach of mice,and one hour later.2 mg/kg LPS was instilled into trachea of mice in ER+PLS group to induce lung injury.Twenty-four hours later,bronchoalveolar lavage fluid (BALF) and lung tissue of mice in four groups were collected.HE staining were used for evaluating pathological changes of lung injury.Lung wet/dry weight ratio,protein concentrations and total cell numbers in the BALF were measured to determine the degree of pulmonary edema.Immunohistochemical staining and Western Blot were used for testing the protein expression of SP-A,Data of multiple groups were analyzed by one way variance (ANOVA) and inter-group comparisons were made by the least significant difference (LSD) tests.Results There was no significant difference in lung injury score (LIS) between control group (0.056±0.008) and ER (0.064±0.037) group,The LIS in LPS group (0.846-±0.047) was higher than that in control group,however the LIS in ER+LPS group (0.279±0.020) was significant lower than that in LPS group (P ＜ 0.05).Lung wet/dry weight,SP-A concentration and total cell numbers in the bronchoalveolar lavage fluid revealed that the degree of pulmonary edema in LPS group was higher than that in control group,and this pulmonary edema was reversed by erlotinib treatment.Immunohistochemical staining and Western blot showed that the expression of SP-A in LPS group was decreased compared with control group,but it was recovered after erlotinib treatment (P ＜ 0.05).Conclusions Erlotinib could protect the LPS-induced ALI,and it may be related to the regulation of SP-A.

The protective effect of broneol on LPS induced acute lung injury / 中国药理学通报

Aim To investigate the effect of broneol on acute lung injury(ALI) induced by lipopolysaccharide (LPS). Methods Male C57 mice were randomly di-vided into saline group, model group, broneol group and dexamethasone group, then the ALI mouse model was induced by instilling intratracheally with LPS. The levels of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),interleukin-6(IL-6) and keratinocyte-de-rived cytokine (KC) were measured at 6h, 12h and 24h after instillation of LPS, and the pathological changes of lung were observed. Mice alveolar macro-phages (MHS) and epithelial cells (MLE-12) were stimulated by LPS. After the stimulation of 1h, 3h, 6h,9h, 12h, 24h, the levels of TNF-α and IL-6 in MHS cells and the contents of KC and macrophage in-flammatory protein-2 (MIP-2) in MLE-12 cells were measured. Results Broneol could inhibit the secre-tion of TNF-α,KC and IL-1β;the early effect of bro-neol on IL-6 was not obvious,but the later effect after the treatment of 24 hours was obvious. After LPS instil-lation 6h and 12h,Broneol could significantly improve lung tissue pathological changes. Broneol had no effect on TNF-α secretion of MHS cells, but it obviously af-fected IL-6 secretion in the later stage. In addition, broneol significantly inhibited KC and MIP2 secretion in MLE-12 cells at the later stage of LPS stimulation. Conclusions Broneol can protect LPS-induced acute lung injury. The mechanism may be related to the inhi-bition of the release of inflammatory factors,the activa-tion of inflammatory cells and the aggregation of neutro-phils.

Analysis of PM2.5 components during winter in Xinxiang city and their inflammatory effects on human type Ⅱ alveolar epithelial cells / 新乡医学院学报

Objective To analyze the PM2.5 components collected during winter in Xinxiang city and their inflammatory effects on human type lⅡ alveolar epithelial cells.Methods Fine particulate matter (PM2.5) was collected during winter in Xinxiang using a high-volume air sampler.The composition and mass concentration of soluble anions and metal elements in PM2.5 were determined with ion chromatography and inductive coupled plasma emission spectrometer,respectively.3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was used to examine the effect of PM2.5 on viability of human type Ⅱ alveolar epithelial cell line A549;enzyme-linked immunosorbent assay was used to examine the expression of interleukin-1β(IL-1β) and interleukin-8 (IL-8) in A549 cells.Results Airborne PM2.5 contained higher levels of NOx and SO42-during winter in Xinxiang city.The amount of PM2.5-derived metal elements in PM2.5 varied significantly,with higher levels of Ca,Mg,Zn and Al.The inhibition ratio of 12.5,25.0,50.0,100.0,200.0,400.0 mg · L-1 pM2.5 group on A549 of human type Ⅱ alveolar epithelial cell was higher than that of 0.0 mg · L-1 PM2.5 group (P ＜ 0.05).The inhibition ratio of 200.0,400.0 mg · L-1 PM2.5 group on A549 of human type Ⅱ alveolar epithelial cell was higher than that of 12.5,25.0,50.0,100.0 mg · L-1 PM2.5 group(P ＜ 0.05).There was no significant difference in the inhibition ratio in the 12.5,25.0,50.0,100.0 mg · L-1 PM2.5 group (P ＞ 0.05),and there was no significant difference in the inhibition ratio between 200.0 mg · L-1 PM2.5 group and 400.0 mg · L-1 PM2.5 group(P ＞ 0.05).Compared with 0.0 mg · L-1 pM2.5 group,the IL-1βand IL-8 protein expression of the human type Ⅱ alveolar epithelial cells culture supernatants in the 25.0,50.0,100.0 mg · L-1PM2.5 group was higher(P ＜0.05).But there was no significant difference in the IL-1β and IL-8 protein expression of human type Ⅱ alveolar epithelial cell culture supernatants among 25.0,50.0,100.0 mg · L-1 pM2.5 group (P ＞ 0.05).Conclusion Analysis of source apportionment suggests that construction and automobiles are main sources of ambient PM2.5 air pollution.Moreover,exposure to PM2.5 can cause damage and pro-inflammatory response of human type Ⅱalveolar epithelial cells.