OBJECTIVETo study the expression of SUMO-modified CCAAT enhancer binding protein α (C/EBPα) in preterm rat model of bronchopulmonary dysplasisa (BPD) induced by hyperoxia exposure and its role.

METHODSEighteen preterm rats were randomly divided into an air group and a hyperoxia group (n=9 each). The model of BPD was prepared in preterm rats exposed to hyperoxia. The rats from the two groups were sacrificed on postnatal days 4, 7 and 14 respectively (3 rats at each time) and lung tissues were harvested. Periodic acid-Schiff (PAS) staining was used to observe the differentiation of rat lung tissues. Ki67 expression was detected by immunohistochemistry. Western blot was used to measure the protein expression of small ubiquitin-related modifier-1(SUMO1) and C/EBPα. A co-immunoprecipitation assay was performed to measure the protein expression of SUMO-modified C/EBPα.

RESULTSCompared with the air group, the hyperoxia group showed a decreased glycogen content in the lung tissue on postnatal day 4, and an increased content on postnatal days 7 and 14. Over the time of hyperoxia exposure, the hyperoxia group showed an increased expression of Ki67 in the lung tissue compared with the air group at all time points. Compared with the air group, the protein expression of C/EBPα increased on postnatal day 4 and decreased on postnatal days 7 and 14 in the hyperoxia group (P<0.05). The hyperoxia group had significantly upregulated expression of SUMO1 and SUMO-modified C/EBPα compared with the air group at all time points (P<0.05). In the hyperoxia group, the protein expression of SUMO-modified C/EBPα was positively correlated with the glycogen content (r=0.529, P<0.05) and the expression of Ki67 (r=0.671, P<0.05).

CONCLUSIONSHyperoxia may induce over-proliferation and differentiation disorders of alveolar epithelial cells in preterm rat model of BPD, possibly through an increased expression of SUMO-modified C/EBP&alpha.

Animals ; Animals, Newborn ; Bronchopulmonary Dysplasia ; etiology ; metabolism ; pathology ; CCAAT-Enhancer-Binding Protein-alpha ; metabolism ; Cell Proliferation ; Disease Models, Animal ; Hyperoxia ; complications ; pathology ; Ki-67 Antigen ; analysis ; Pulmonary Alveoli ; pathology ; Rats ; Rats, Sprague-Dawley ; Sumoylation

Irreversible destruction of bronchi and alveoli can lead to multiple incurable lung diseases. Identifying lung stem/progenitor cells with regenerative capacity and utilizing them to reconstruct functional tissue is one of the biggest hopes to reverse the damage and cure such diseases. Here we showed that a rare population of SOX9 basal cells (BCs) located at airway epithelium rugae can regenerate adult human lung. Human SOX9 BCs can be readily isolated by bronchoscopic brushing and indefinitely expanded in feeder-free condition. Expanded human SOX9 BCs can give rise to alveolar and bronchiolar epithelium after being transplanted into injured mouse lung, with air-blood exchange system reconstructed and recipient's lung function improved. Manipulation of lung microenvironment with Pirfenidone to suppress TGF-β signaling could further boost the transplantation efficiency. Moreover, we conducted the first autologous SOX9 BCs transplantation clinical trial in two bronchiectasis patients. Lung tissue repair and pulmonary function enhancement was observed in patients 3-12 months after cell transplantation. Altogether our current work indicated that functional adult human lung structure can be reconstituted by orthotopic transplantation of tissue-specific stem/progenitor cells, which could be translated into a mature regenerative therapeutic strategy in near future.
Bronchiectasis ; genetics ; metabolism ; Humans ; Pulmonary Alveoli ; cytology ; metabolism ; SOX9 Transcription Factor ; genetics ; metabolism ; Stem Cell Transplantation ; methods ; Stem Cells ; cytology ; metabolism

OBJECTIVETo explore the expression of CASZ1 and its relationship with the pulmonary microvascular development in lung tissue of newborn rats exposed to hyperoxia which induced bronchopulmonary dysplasia (BPD).

METHODForty-eight newborn Sprague Dawley(SD) rats (male and female unlimited) were randomly divided into two groups: experimental group and control group according to random digits table with 24 in each.The rats in experimental group were exposed to high oxygen volume fraction of 800 ml/L and the rats in control group were exposed to normal air. Eight rats were randomly selected from each group on day 3 and 7 after oxygen exposure.The sections of lung were stained with HE method in order to assess lung histological changes, the alveolar development was evaluated by the number of radial alveolar count (RAC) and septal wall thickness. CD31 was detected by immunohistochemistry (IHC) method and the capillary density was calculated. The location, distribution and expression of CASZ1 in the lung tissue were detected by the immunohistochemistry, Western blotting, and quantitative PCR (qPCR).

RESULT(1) Stained by HE, lungs of experimental group showed destroyed alveoli, alveoli fusion and increased septal wall thickness, RAC were significantly lower than those in control group(14 d: septal wall thickness (12.69 ± 0.63) μm vs. (6.53 ± 0.16) μm, RAC 5.9 ± 0.4 vs. 8.4 ± 1.0, t = 19.046, 4.760, P both = 0.000). (2) CD31 protein was expressed predominantly in cytoplasm of pulmonary microvascular endothelial cells. The experimental group CD31 average optical density (AIOD) were decreased compared with control group((16.6 ± 1.6) × 10(3) vs.(40.1 ± 2.4) × 10(3), (18.1 ± 1.4) × 10(3) vs.(83.2 ± 5.2) × 10(3), (49.2 ± 5.4) × 10(3) vs.(136.2 ± 28.1) × 10(3), t=16.185, 16.066 and 6.078, P<0.01 for all comparisons). Capillary density in experimental group was also significantly decreased compared with control group ((3.84 ± 0.15)% vs.(6.01 ± 0.22)%, (4.17 ± 0.38)% vs.(6.15 ± 0.24)%, (5.43 ± 0.44)% vs. (9.13 ± 0.25)%, t = 16.124, 8.773 and 14.076, P all < 0.01). (3)RT-qPCR and Western blotting showed that the CASZ1 mRNA significantly increased in experimental group compared with control group(0.56 ± 0.17 vs. 1.00 ± 0.26, 0.32 ± 0.29 vs. 0.58 ± 0.14, 0.14 ± 0.22 vs. 0.56 ± 0.15, t=3.890, 3.303 and 2.388, P < 0.05 for all comparisons), and the protein expression of CASZ1 also significantly increased in experimental group compared with control group (0.65 ± 0.02 vs. 0.78 ± 0.23, 0.46 ± 0.03 vs. 0.75 ± 0.05, 0.34 ± 0.22 vs. 0.75 ± 0.04, t=6.200 and 10.485 and 14.998, P < 0.05 for all comparisons). (4)The protein level of CASZ1 in experimental group was positively correlated with capillary density (r=0.519, P<0.01).

CONCLUSIONCASZ1 is involved in the whole process of newborn rats BPD and may be linked to pulmonary microvascular dysplasia.

Animals ; Animals, Newborn ; Bronchopulmonary Dysplasia ; pathology ; Female ; Hyperoxia ; pathology ; Lung ; blood supply ; pathology ; Male ; Oxygen ; adverse effects ; Pulmonary Alveoli ; RNA, Messenger ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Transcription Factors ; metabolism

OBJECTIVETo study the association between endoplasmic reticulum stress (ERS) pathway mediated by inositol-requiring kinase 1 (IRE1) and the apoptosis of type II alveolar epithelial cells (AECIIs) exposed to hyperoxia.

METHODSThe primarily cultured AECIIs from preterm rats were devided into an air group and a hyperoxia group. The model of hyperoxia-induced cell injury was established. The cells were harvested at 24, 48, and 72 hours after hyperoxia exposure. An inverted phase-contrast microscope was used to observe morphological changes of the cells. Annexin V/PI double staining flow cytometry was performed to measure cell apoptosis. RT-PCR and Western blot were used to measure the mRNA and protein expression of glucose-regulated protein 78 (GRP78), IRE1, X-box binding protein-1 (XBP-1), and C/EBP homologous protein (CHOP). An immunofluorescence assay was performed to measure the expression of CHOP.

RESULTSOver the time of hyperoxia exposure, the hyperoxia group showed irregular spreading and vacuolization of AECIIs. Compared with the air group, the hyperoxia group showed a significantly increased apoptosis rate of AECIIs and significantly increased mRNA and protein expression of GRP78, IRE1, XBP1, and CHOP compared at all time points (P<0.05). The hyperoxia group had significantly greater fluorescence intensity of CHOP than the air group at all time points. In the hyperoxia group, the protein expression of CHOP was positively correlated with the apoptosis rate of AECIIs and the protein expression of IRE1 and XBP1 (r=0.97, 0.85, and 0.88 respectively; P<0.05).

CONCLUSIONSHyperoxia induces apoptosis of AECIIs possibly through activating the IRE1-XBP1-CHOP pathway.

Animals ; Apoptosis ; Cells, Cultured ; Endoplasmic Reticulum Stress ; physiology ; Endoribonucleases ; physiology ; Epithelial Cells ; physiology ; Female ; Hyperoxia ; metabolism ; pathology ; Multienzyme Complexes ; physiology ; Protein-Serine-Threonine Kinases ; physiology ; Pulmonary Alveoli ; pathology ; Rats ; Rats, Sprague-Dawley ; Transcription Factor CHOP ; physiology ; X-Box Binding Protein 1 ; physiology

In the study, the effects of Panax notoginseng saponins (PNS) on alveolar epithelial to mesenchymal transition (EMT) and extracellular matrix degradation were observed in a type of human alveolar epithelial cell, A549 cells, stimulated by TGF-beta1. Firstly, MTT method was applied to evaluation of cellular proliferation and found that PNS from 12.5 mg x L(-1) to 200 mg x L(-1) dosage could not inhibit significantly cellular proliferation. Then, cells were divided into five groups, normal group, TGF-beta1 group, TGF-beta1 + 50 mg x L(-1) PNS group, TGF-beta1 + 100 mg x L(-1) PNS group and TGF-beta1 + 200 mg x L(-1) PNS group. Normal cells were not stimulatec by TGF-beta1; TGF-beta1 cells were only stimulated by TGF-beta1 and the other cells were stimulated by TGF-beta1 with different doses of PNS, respectively. After stimulation, cells and supernatants were collected for assays. Cellular roundness was applied to quantitative evaluation of morphological change. Immunocytochemistry was applied to examine E-cadherion, a-SMA and FN proteins expression in the cells. Enzyme linked-immunosorbent assay was applied to MMP-9 and TIMP-1 levels. The results showed that EMT of A549 cells was induced by TGF-beta1, showing significant change of roundness, E-cadherion, alpha-SMA and FN (P < 0.05, P < 0.01). Compared to TGF-beta1, PNS significantly inhibited the changes of roundness (P < 0.05), FN and alpha-SMA (P < 0.05, P < 0.01) and not significantly inhibited the change of E-cadherion. Furthermore, MMP-9 levels were significantly increased by TGFbeta1 stimulation (P < 0.05), without significant change of TIMP-1. Compared with TGF-beta1, PNS could significantly increase MMP-9 level (P < 0.05) and decrease TIMP-1 levels (P < 0.05, P < 0.01). In conclusion, PNS could inhibit alveolar epithelial cell EMT induced by TGF-beta1, with increase of extracellular matrix degradation ability, which showed anti-fibrosis of lung ability.
Cell Proliferation ; drug effects ; Drugs, Chinese Herbal ; pharmacology ; Epithelial-Mesenchymal Transition ; drug effects ; Humans ; Matrix Metalloproteinase 9 ; metabolism ; Panax notoginseng ; chemistry ; Pulmonary Alveoli ; cytology ; drug effects ; metabolism ; Saponins ; pharmacology ; Transforming Growth Factor beta1 ; metabolism

OBJECTIVETo investigate the effect of arginine vasopressin (AVP) on alveolar fluid clearance (AFC) in acute lung injury (ALI).

METHODSForty-eight healthy adult Sprague-Dawley rats were randomly divided into control group, ALI model group and AVP treatment group. The pathological changes in the lungs, lung water content, alveolar permeability and AFC were observed, and the expressions of alveolar epithelial sodium channel (ENaC) and Na⁺, K⁺-ATPase were measured.

RESULTSCompared with those in the model group, the rats treated with AVP showed significantly decreased alveolar permeability (0.27 ± 0.15 vs 0.59 ± 0.19) and lung water content (5.01 ± 1.59 vs 8.67 ± 1.79) (P<0.05) and increased AFC (23.56 ± 4.51 vs 8.28 ± 3.57) and of α-ENaC expressions (1.296 ± 0.322 vs 0.349 ± 0.141) and α1-Na⁺, K⁺-ATPase (1.421 ± 0.389 vs 0.338 ± 0.186) (P<0.05).

CONCLUSIONAVP can promote AFC in with ALI possibly by up-regulation of α-ENaC, α1-Na⁺, and K⁺-ATPase.

Acute Lung Injury ; drug therapy ; Animals ; Arginine Vasopressin ; pharmacology ; Epithelial Sodium Channels ; metabolism ; Lung ; drug effects ; pathology ; Pulmonary Alveoli ; drug effects ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Sodium-Potassium-Exchanging ATPase ; metabolism

OBJECTIVETo explore the roles of PKCβ/P66Shc oxidative stress signal pathway in mediating hyperoxia-induced reactive oxgen species (ROS) production in alveolar epithelial cells (A549) and the protective effects of PKCβ inhibitor on hyperoxia-induced injuries of alveolar epithelial cells.

METHODSA549 cells were cultured in vitro and randomly divided into three groups: control, hyperoxia and PKCβ inhibitor LY333531 treatment. The hyperoxia group was exposed to a mixture of O2 (950 mL/L) and CO2 (50 mL/L) for 10 minutes and then cultured in a closed environment. The LY333531 group was treated with PKCβ inhibitor LY333531 of 10 µmol/L for 24 hours before hyperoxia induction. Cells were collected 24 hours after culture and the levels of PKCβ, Pin1, P66Shc and P66Shc-Ser36 were detected by Western blot. The intracellular translocation of P66Shc, the production of ROS and cellular mitochondria membrane potential were measured using the confocal microscopy.

RESULTSCompared with the control group, the levels of PKCβ, Pin1, P66Shc and P-P66Shc-Ser36 in A549 cells 24 hours after culture increased significantly in the hyperoxia group. These changes in the hyperoxia group were accompanied with an increased translocation rate of P66Shc from cytoplasm into mitochondria, an increased production of mitochondrial ROS, and a reduced mitochondrial membrane potential. Compared with the hyperoxia group, the levels of Pin1, P66Shc and P66Shc-Ser36 in A549 cells, the translocation rate of P66Shc from cytoplasm into mitochondria and the production of mitochondrial ROS decreased significantly, while the mitochondrial membrane potential increased significantly in the LY333531 treatment group. However, there were significant differences in the above mentioned measurements between the LY333531 treatment and control groups.

CONCLUSIONSHyperoxia can increase the expression of PKCβ in alveolar epithelial cells and production of mitochondrial ROS and decrease mitochondrial membrane potential. PKCβ inhibitor LY333531 can partially disrupt these changes and thus alleviate the hyperoxia-induced alveolar epithelial cell injury.

Cell Hypoxia ; Cells, Cultured ; Epithelial Cells ; metabolism ; Humans ; Indoles ; pharmacology ; Maleimides ; pharmacology ; Oxidative Stress ; Protein Kinase C beta ; physiology ; Pulmonary Alveoli ; cytology ; metabolism ; Reactive Oxygen Species ; metabolism ; Shc Signaling Adaptor Proteins ; physiology ; Signal Transduction ; physiology ; Src Homology 2 Domain-Containing, Transforming Protein 1

Fetal lung development normally occurs in a hypoxic environment. Hypoxia-inducible factor (HIF)-1alpha is robustly induced under hypoxia and transactivates many genes that are essential for fetal development. Most preterm infants are prematurely exposed to hyperoxia, which can halt hypoxia-driven lung maturation. We were to investigate whether the HIF-1alpha inducer, deferoxamine (DFX) can improve alveolarization in a rat model of bronchopulmonary dysplasia (BPD). A rat model of BPD was produced by intra-amniotic lipopolysaccharide (LPS) administration and postnatal hyperoxia (85% for 7 days), and DFX (150 mg/kg/d) or vehicle was administered to rat pups intraperitoneally for 14 days. On day 14, the rat pups were sacrificed and their lungs were removed and examined. A parallel in vitro study was performed with a human small airway epithelial cell line to test whether DFX induces the expression of HIF-1alpha and its target genes. Alveolarization and pulmonary vascular development were impaired in rats with BPD. However, DFX significantly ameliorated these effects. Immunohistochemical analysis showed that HIF-1alpha was significantly upregulated in the lungs of BPD rats treated with DFX. DFX was also found to induce HIF-1alpha in human small airway epithelial cells and to promote the expression of HIF-1alpha target genes. Our data suggest that DFX induces and activates HIF-1alpha, thereby improving alveolarization and vascular distribution in the lungs of rats with BPD.
Animals ; Bronchopulmonary Dysplasia/*drug therapy/*metabolism/pathology ; Deferoxamine/*administration & dosage ; Female ; Hypoxia-Inducible Factor 1, alpha Subunit/*metabolism ; Male ; Pulmonary Alveoli/drug effects/*growth & development/metabolism/pathology ; Pulmonary Veins/drug effects/*growth & development/pathology ; Rats ; Rats, Sprague-Dawley ; Treatment Outcome ; Up-Regulation/drug effects

OBJECTIVETo investigate the protective effect of curcumin (CU) on type II alveolar epithelial cells (A549 cells) during paraquat (PQ)-induced oxidative damage and its underlying mechanism.

METHODSRoutinely cultured A549 cells were divided into blank control group, CU control group, PQ group, and PQ+Cu group to receive respective treatments for 24 h. Cell viability was determined by MTT assay. The NFE2L2 expression in A549 cells was measured by RT-PCR and Western blot. The activities of the heme oxygenase-1 (HO-1) and NAD (P) H: quinone oxidoreductase 1 (NQO-1) in cells and the superoxide dismutase (SOD) and catalase (CAT) in supernatant, as well as malondialdehyde (MDA) content, were measured by enzyme-linked immunosorbent assay. After siRNA depletion of Nrf2, the protective effect of CU on A549 cells during PQ-induced oxidative damage was evaluated.

RESULTSPQ, even at a dose of 0.1 mmol/L, could significantly suppress the viability of A549 cells in a dose-dependent manner. CU showed no significant inhibitory effect on the viability of A549 cells when given at a dose below 160 ümol/L. Compared with the blank control group, the PQ group had significantly decreased SOD activity and significantly increased CAT activity and MDA content after 24-h exposure to 800 ümol/L PQ (P < 0.05 or P < 0.01). Thanks to pretreatment with 80 ümol/L CU, the PQ+CU group had significantly increased SOD and CAT activities and significantly decreased MDA content compared with the PQ group (P < 0.01). Compared with the blank control group, the PQ group had significantly increased expression of NFE2L2 and its downstream factors HO-1 and NQO-1 (P < 0.01), while the PQ+CU group had significantly higher expression of NFE2L2, HO-1,and NQO-1 than the PQ group (P < 0.01).Compared with the PQ+CU group, the CU+PQ+NFE2L2siRNA group had significantly decreased SOD and CAT activities and significantly increased MDA content (P < 0.01).

CONCLUSIONLow-dose CU significantly reduces the PQ-induced oxidative damage in A549 cells in vitro by activation of the Nrf2-ARE pathway.

Cell Line ; Curcumin ; pharmacology ; Humans ; NF-E2-Related Factor 2 ; metabolism ; Oxidation-Reduction ; Oxidative Stress ; Paraquat ; toxicity ; Pulmonary Alveoli ; cytology ; metabolism ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism

This study is to investigate the effect of artesunate on transforming growth factor-beta1 (TGF-beta1) induced epithelial-mesenchymal transition (EMT) and its possible mechanism. After the in vitro cultured RLE-6TN cells were treated with TGF-beta1 then artesunate intervened on it, after 24 h, expression of the markers of mesenchymal cell was assayed using Western blotting and real-time PCR analysis. Western blotting was also used to detect the effect of TGF-beta1 on the Smad3 and Smad7 expressions of RLE-6TN cells. Morphological alterations were examined by phase-contrast microscope, and ultrastructure changes by electron microscope. Incubation of RLE-6TN cells with TGF-beta1 resulted in the up-regulation of the expression of the mesenchymal cell markers, after artesunate intervened on it, resulted in the down-regulation of the expression. Meanwhile, incubation with artesunate intervened on RLE-6TN cells could lead to the apparent down-regulation of the expression of Smad3 and up-regulation of Samd7 and the transition of RLE-6TN cells to mesenchymal-like by TGF-beta1 induction, after artesunate intervened on it, RLE-6TN cells to epithelial-like. TGF-beta1 induced epithelial-mesenchymal transition process; artesunate can inhibit TGF-beta1-induced epithelial-mesenchymal transition process, the possible mechanism is up-regulation of the expression of Smad7 and down-regulation of the expression of Smad3, meanwhile inhibits phosphorylation of Smad3.
Actins ; genetics ; metabolism ; Animals ; Artemisia ; chemistry ; Artemisinins ; isolation & purification ; pharmacology ; Cell Line ; Cell Proliferation ; drug effects ; Epithelial Cells ; cytology ; metabolism ; Epithelial-Mesenchymal Transition ; drug effects ; Idiopathic Pulmonary Fibrosis ; pathology ; Plants, Medicinal ; chemistry ; Pulmonary Alveoli ; cytology ; RNA, Messenger ; metabolism ; Rats ; Smad3 Protein ; genetics ; metabolism ; Smad7 Protein ; genetics ; metabolism ; Transforming Growth Factor beta1 ; pharmacology ; Vimentin ; genetics ; metabolism