Regulatory effect of retinoid X receptor on oxidative stress response in-duced by hypoxia/reoxygenation in rat type Ⅱ alveolar epithelial cells / 中国病理生理杂志

AIM:To investigate the regulatory role of retinoid X receptor(RXR)in oxidative stress response of rat type Ⅱ alveolar epithelial cells(AECII)induced by hypoxia/reoxygenation(HR).METHODS:The AECII were di-vided into control(C)group,HR group,HR+solvent dimethyl sulfoxide(DMSO)group(HD group),HR+RXR agonist 9-cis-retinoic acid(9-RA)group(RA group),and HR+RXR antagonist HX531 group(HX group).Cell Counting Kit-8(CCK-8)method was used to measure the cell viability.Immunofluorescence staining was used to detect the expression of surfactant protein A(SP-A)and RXRα in AECII.Kits were detected to the levels of superoxide dismutase(SOD)and malondialdehyde(MDA)in cells.Transmission electron microscopy was used to observe the ultrastructural changes of the cells.Western blot was used to detect the protein level of nuclear factor E2-related factor 2(Nrf2).RT-PCR was used to detect the expression level of Nrf2 mRNA.RESULTS:Compared with C group,the cell viability and SOD activity in HR,HD,RA and HX groups were decreased significantly(P<0.05),the MDA content were increased significantly(P<0.05),the Nrf2 mRNA and protein expression levels were decreased significantly(P<0.05 or P<0.01),and the immuno-fluorescence expression of RXRα was significantly increased(P<0.01).Compared with HR and HX groups,the cells in RA group showed significantly increased cell viability(P<0.05),increased SOD activity(P<0.05),decreased MDA con-tent(P<0.05),increased Nrf2 mRNA and protein expression levels(P<0.01),and significantly increased immunofluo-rescence expression of RXRα(P<0.01).CONCLUSION:Hypoxia/reoxygenation can aggravate the oxidative stress re-sponse of rat AECII,and RXR agonist intervention can alleviate HR-induced rat AECII injury by inhibiting oxidative stress.

Acacetin ameliorates alveolar epithelial cell damage caused by Streptococcus pneumoniae infection by regulating Sirt1-mediated AMPK/Nrf2 signaling pathway / 中国免疫学杂志

Objective:To investigate effect of acacetin on alveolar epithelial cell damage caused by Streptococcus pneumoniae(SP)infection by regulating sirtuin 1(Sirt1)-mediated 5'-AMP activated protein kinase(AMPK)/nuclear factor erythroid-2 related factor 2(Nrf2)signaling pathway.Methods:Alveolar epithelial cells A549 cultured in vitro were infected with SP to establish a cell damage model.After treatment with acacetin at final concentrations of 0,5,25,50,100,150,200 μmol/L,CCK-8 was performed to detect cell viability of each treatment group and optimal concentration of acacetin was screened.A549 cells cultured in vitro were ran-domly separated into five groups:control group,model group,acacetin(150 μmol/L)group,EX527(Sirt1 inhibitor,40 μmol/L)group,acacetin(150 μmol/L)+EX527(40 μmol/L)group,control group was not treated,other groups were infected with SP to establish a cell damage model,and then treated with 150 μmol/L acacetin and 40 μmol/L EX527,CCK-8 and flow cytometry were performed to measure cell viability and apoptosis rate in each group;kits were performed to measure levels of reactive oxygen species(ROS),superoxide dismutase(SOD),malondialdehyde(MDA),lactate dehydrogenase(LDH)and IL-10,IL-1β,TNF-α levels of cells in each group;Western blot was performed to measure proliferation-related proteins Ki-67,proliferating cell nuclear antigen(PCNA),apoptosis-related proteins caspase-9,Bax,Sirt1 and AMPK/Nrf2 signaling pathway proteins p-AMPK/AMPK,Nrf2 expres-sions of cells in each group.Results:Model group had decreased A549 cell viability,SOD and IL-10 levels,p-AMPK/AMPK,Sirt1,Nrf2,Ki-67 and PCNA protein expressions(P<0.05),and increased apoptosis rate,MDA,LDH,ROS,IL-1β and TNF-α levels than control group(P<0.05).Compared with model group and acacetin+EX527 group,acacetin group had increased A549 cell viability,SOD and IL-10 levels,p-AMPK/AMPK,Sirt1,Nrf2,Ki-67 and PCNA protein expressions(P<0.05),and decreased apoptosis rate,MDA,LDH,ROS,IL-1β and TNF-α levels(P<0.05);EX527 group had decreased A549 cell viability,SOD and IL-10 levels,p-AMPK/AMPK,Sirt1,Nrf2,Ki-67 and PCNA protein expressions(P<0.05),and increased apoptosis rate,MDA,LDH,ROS,IL-1β and TNF-α levels(P<0.05).Conclusion:Acnestin can activate AMPK/Nrf2 signaling by up-regulating Sirt1 expression,thereby promoting secretion of anti-inflammatory factors,reducing production of ROS and pro-inflammatory factors,reducing inflammation and oxidative stress,and finally alleviating neuronal damage.

Effect of miR-141-3p targeting HMGB1 on LPS-induced A549 cell injury / 安徽医科大学学报

Objective @#To investigate the effect of miR-141-3p on LPS induced A549 cell injury by targeting high mobility group protein 1 (HMGB1) ．@*Methods @#A549 cells derived from type Ⅱ alveolar epithelial cells were taken as the study object，miR-141-3p mimics，mimics NC，HMGB1 gene overexpression plasmid (pcDNA3. 1-HMGB1) and empty Vector were transfected into A549 cells respectively or co-transfected，then 10 μg / ml LPS was used for 24 h．Cell proliferation activity was detected by cell counting kit-8 ( CCK-8) ．The activity of lactate dehydrogenase ( LDH) in the supernatant of cell culture was detected by colorimetry．The apoptosis level of each group was detec- ted by flow cytometry．The levels of interleukin (IL) -1 β , IL-6 and tumor necrosis factor α (TNF-α) were detected by enzyme-linked immunosorbent assay (Elisa) ．Dual luciferase reporter gene assay verified the targeted regulatory relationship between miR-141-3p and HMGB1 . @*Results @#After treatment with LPS ，the proliferative activity of A549 cells and the expression level of miR-141-3p decreased ( P ＜0. 05 ) ，the apoptosis rate increased ( P < 0. 05) ，the levels of IL-1 β , IL-6，TNF-α and the activity of LDH in supernatant increased (P＜0. 05) ．Overex- pression of miR-141-3p increased the proliferation activity of A549 cells treated with LPS (P ＜0. 05 ) ，and de- creased the apoptosis rate and the levels of IL-1 β , IL-6，TNF-α in cells and LDH activity in supernatant (P < 0. 05) ．However，overexpression of HMGB1 gene could reverse the ameliorative effect of miR-141-3p on LPS-in- duced A549 cell injury．Dual luciferase reporter gene experiment confirmed that HMGB1 was the downstream target gene of miR-141-3p．@*Conclusion @# miR-141-3p can inhibit LPS-induced apoptosis，reduce the expression level of inflammatory factors，and improve the damage of A549 cells，which may be related to the targeted regulation of HMGB1 expression.

Mechanism of ferroptosis induced by endoplasmic reticulum stress in sepsis related lung injury / 安徽医科大学学报

Objective @#To explore the mechanism of ferroptosis induced by endoplasmic reticulum stress (ERs ) in acute respiratory distress syndrome (ARDS) .@*Methods @#In order to determine the effects of LPS on oxidative stress and Fe2 + level of mouse capillary alveolar epithelial cells (MLE12 cells ) , the cells were treated with LPS (0 , 1 , 2 , 5 μg/ml) for 24 h . To verify the role of ferroptosis in lipopolysaccharide ( LPS)-induced cell death , MLE12 cells were divided into control ( Con ) group , iron removal inhibitor ( Fer-1) group , LPS group and LPS + Fer-1 group . LPS + Fer-1 group was pretreated with 10 μmol/L Fer-1 for 6 h , then the cells were exposed to 5 μg/ml LPS for 24 h . Con group was treated with solvent DMSO for 24 h . Fer-1 group was pretreated with 10 μmol/L Fer-1 for 6 h , and then treated with DMSO for 24 h . The cells in LPS group were exposed to 5 μg/ml LPS for 24 h . The MLE12 cells were divided into three groups : Con + Vector group , Con + sequence similarity family 134 mem ber B ( FAM134B ) group , LPS + Vector group and LPS + FAM134B group . After transfected with vector or FAM134B overexpression plasmid for 48 h , the cells were exposed or not exposed to 5 μg/ml LPS for 24 h . Cell viability was measured by CCK-8 . The levels of malondialdehyde (MDA) , glutathione and iron , the protein levels of ferroptosis markers [ cyclooxygenase 2(PTGS2) , glutathione peroxidase 4(GPX4)] and ERs markers [glucose reg ulatory protein 78( GRP78) , activated transcription factor 4 ( ATF4) and C/EBP homologous protein ( CHOP)] were measured in different groups . In order to further confirm the results of in vitro cell experiments , 40 mice were randomly divided into Con + Vector group , Con + FAM134B group , LPS + Vector group and LPS + FAM134B group , with 10 mice in each group . LPS induced sepsis models were established in LPS + Vector group and LPS + FAM134B group , and the levels of GPX4 and ERs in lung tissue were evaluated by immunofluorescence staining and protein blot. @*Results @#LPS treatment increased the levels of PTGS2 and MDA , and decreased the levels of GPX4 and GSH in MLE12 cells in a dose dependent manner. Compared with LPS group , the cell viability , GPX4 and GSH levels in LPS + Fer-1 group increased significantly (P < 0.05) , while the PTGS2 protein level and MDA level decreased significantly (P < 0.05) . Compared with LPS + Vector group , LPS + FAM134B group significantly increased cell viability (P < 0.05) , decreased PTGS2 protein level (P < 0.05) and increased GPX4 level ( P < 0.05) . At the same time , the level of MDA in LPS + FAM134B group was lower than that in LPS + Vector group (P < 0.05) , and the level of GSH was higher than that in LPS + Vector group (P < 0.05) . In animal experiment , compared with LPS + Vector group , the expression levels of 4 HNE , ATF4 and CHOP in lung tissue of LPS + FAM134B group decreased significantly ( P < 0.05 ) , and the expression levels of GPX4 , FAM134B group in creased significantly (P < 0.05) .@*Conclusion @#LPS induces ferroptosis and ERs in MLE12 cells in a dose depend ent manner. Activating the endoplasmic reticulum autophagy associated FAM134B receptor helps to inhibit ERs and alleviate cell ferroptosis .

Effects of wedelobata on apoptosis and secretion of inflammatory cytokines in the alveolar epithelium infected by Streptococcus pneumonia / 实用医学杂志

Objective To investigate the regulatory effects of wedelobata on apoptosis and secretion of inflammatory factors in the alveolar epithelial cells infected by Streptococcus pn e um on i a e.Methods Alveolar epithelial cells A549 were divided into infection group(1×108/CFU/mL cultured cells of Streptococcus pneumoniae),control group(no treatment),infection+wedelolactone low-dose group,middle-dose group and high-dose group(pretreated with wedelolactone at 10,20 and 40 μmol/L and then cultured cells of Streptococcus pneumoniae at 1×108/CFU/mL).Alveolar epithelial cells A549 were divided into infection group(1×108/CFU/mL cultured cells of Streptococcus pneumoniae),control group(no treatment),infection+wedelolactone low-dose group,middle-dose group and high-dose group(pretreated with wedelolactone at 10,20 and 40 μmol/L and then cultured cells of Streptococcus pneumoniae at 1×108/CFU/mL).Results Compared with control group,the apoptosis rate,the relative expression levels of Bax,Caspase-3 protein,IL-6,IL-1β and TNF-α mRNA were higher in infection group,infection + wedelolide low dose group,medium dose group and high dose group,while the expression level of Bcl-2 protein was lower(P＜0.05).Compared with the infected group,the apoptosis rate,the relative expression levels of Bax,Caspase-3 protein,IL-6,IL-1β and TNF-α mRNA and the expression levels of Bcl-2 protein were lower in the infected + wedelolide low dose,medium dose and high dose groups.Moreover,the apop-tosis rate,the expression levels of Bax,Caspase-3 protein,IL-6,IL-1β and TNF-α mRNA were the highest in the infected + wedelactone high-dose group,and the expression levels of Bcl-2 protein were the lowest(P＜0.05).Conclusion The apoptosis rate of alveolar epithelial cells infected by Streptococcus pneumoniae decreased and the secretion of inflammatory factors decreased after the intervention of wedelia lactone.

Involvement of RNF99 in potential link between ubiquitination and septic shock via TAK1/NF-κB signal-ing pathway / 实用医学杂志

Objective To explore the potential relationship between ubiquitination of transforming growth factor kinase 1(TAK1)/nuclear factor-κB(NF-κB)signaling pathway mediated by ring finger protein 99(RNF99)and septic acute respiratory distress syndrome(ARDS).Methods Plasmid and siRNA transfection were conducted to overexpress or knock down RNF99 in MLE12,and expressions of p65 phosphate and p65 protein were analyzed.The protein interaction between RNF99 and TRAF6 or TAK1 was analyzed by immunoprecipitation assay.Forty mice were randomly divided into WT plus PBS,WT plus LPS,RNF99 specific expression(TG)plus PBS,and TG plus LPS groups,with 10 mice in each group.Sepsis was induced by intraperitoneal injection of 30 mg/kg LPS.Results As compared with vector group,protein expression levels of TRAF6 and TAK1 in MLE12 cells decreased significantly in RNF99 group(P<0.05).Ubiquitinated TRAF6 protein increased in MLE12 cells with RNF99 knockdown.As compared with LPS plus vector group,phosphorylation level of p65 in MLE12 cells was signifi-cantly lower in LPS plus RNF99 group(P<0.05).As compared with si-NC group,protein expression levels of RNF99 and IκBα in si-RNF99 group decreased significantly(P<0.05).As compared with LPS plus si-NC group,phosphorylation level of p65 in LPS plus si-RNF99 group increased significantly(P<0.05).The staining percentage of CD68 macrophages in lung tissues was significantly lower in TG plus LPS group than in WT plus LPS group(P<0.05).Phosphorylation level of p65 in lung tissues was significantly lower in TG plus LPS group than in WT plus LPS group(P<0.05).Conclusion RNF99 regulates NF-κB signaling pathway by interacting with the key regulator of NF-κB signaling pathway(TRAF6/TAK1),and improves lung injury after intraperitoneal injection of LPS in mice.

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.

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.

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.

Effect of a novel phosphodiesterase type 5 inhibitor, CPD1, on paraquat-induced lung fibrosis in rats / 中国药理学通报

Aim To investigate the effects of CPD1, a novel phosphodiesterase 5 inhibitor, on lung pathological phenotype and epithelial-mesenchymal transition of alveolar epithelial cells in lung fibrosis model rats caused by paraquat (PQ). Methods Lung fibrosis model was constructed by a single intraperitoneal injection of PQ (30 mg·kg

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

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.

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.

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.

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.

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.