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Objective:To investigate the expression of long non-coding RNA metastasis associated lung adenocarcinoma transcript 1(lncRNA MALAT1) in bronchopulmonary dysplasia (BPD) of neonatal rats induced by hyperoxia and its effect on alveolar type 2 epithelial cells (AEC Ⅱ).Methods:The lung injury model of neonatal SD rats induced by hyperoxia(model group, n=50, inhaled oxygen concentration of 80%-85%) and the control group(inhaled air, n=50) were prepared.Lung tissue samples were taken and retained on days 1, 3, 7, 14 and 21, and the physiological and pathological changes of lung tissue were detected by paraffin-embedded sections and hematoxylin-eosin staining; The dynamic expression of lncRNA MALAT1 in lung tissue was detected by real-time fluorescent quantitative polymerase chain reaction; The dynamic expression of surfactant protein C(SPC) in lung tissue and AECⅡ was detected by Western blot.AECⅡ was extracted from lung tissue of normal newborn rats, and lncRNA MALAT1 was knocked down by siRNA.The cells were collected and Western blot as well as immunofluorescence were used to detect the changes of SPC. Results:The lung tissue of model group gradually became thickened with alveolar compartments, and the alveolar cavity was enlarged with the disappearance of alveolar spine and other pathological structural changes.Compared with the control group, there was no difference in the expression of lncRNA MALAT1 and SPC in the lung tissue from model group on days 1, 3( P>0.05), but the expression of lncRNA MALAT1 and SPC significantly increased on days 7, 14 and 21( P<0.05). When lncRNA MALAT1 was inhibited, SPC expression showed a decrease trend. Conclusion:Hyperoxia can lead to the stagnation of lung development in neonatal rats, and the structure and function of alveolar disorders are impaired.The expression of lncRNA MALAT1 is involved in the process of hyperoxia-induced BPD in neonatal rats.The increase of lncRNA MALAT1 may promote the proliferation of AECⅡ.
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Objectives To determine the effect of Hippo signaling pathway on lung injury repair of bone-marrow derived mesenchymal stem cells (mMSCs) in murine lipopolysaccharide (LPS) induced acute respiratory distress syndrome (ARDS).Methods C57BL/6 mouse bone marrow-derived MSC (mMSCs) cell lines with low expression of large tumor suppressor 1 (LATS 1) were constructed by lentiviral vector transfection.ARDS was modeled by intratracheally injection of 2 mg/mL lipopolysaccharide (LPS)50 μL.C57BL/6 mice were randomly(random number) divided into four groups (n=36):normal control group,ARDS group,ARDS mice transplanted with mMSCs transfected with blank lentivirus vector (MSC-shcontrol group) or sh-LATS 1 lentivirus vector (MSC-shLATS 1 group).Mice were sacrificed at 3,7,and 14 d after modeling,and lung tissue and bronchoalveolar lavage fluid (BALF) were collected.Near-infrared fluorescence imaging,immunofluorescence staining and Western blot were used to evaluate retention and differentiation of mMSCs in lung tissue.Lung tissue wet weight/body weight ratio (LWW/BW) and total protein (TP) and albumin (ALB) in BALF were determined to reflect pulmonary edema.The expression of Occludin protein in lung epithelium was tested by Western blot.The levels of interleukins (IL-1β,IL-6,and IL-10) in BALF were assessed by enzyme-linked immunosorbent assay (ELISA).Lung injury score and pulmonary fibrosis score in lung tissue were assessed.Results The retention ofmMSCs at 3,7 and 14 d in the MSC-shLATS1 group were significantly higher than those in the MSC-shcontrol group [(26.25±4.58) vs (12.13±3.75) cells/HP,(20.49±3.86) vs (9.97±2.76) cells/HP,and (13.77±3.55) vs (6.89±2.10) cells/HP.all P＜0.05],so was the differentiation of mMSCs into type Ⅱ alveolar epithelial cells at 14 d [(64.12±15.29)％ vs (19.64±3.71)％,P＜0.05].LWW/BW and TP and ALB in BALF at 3 and 14 d in the MSC-shLATS1 group [(9.85±1.51),(6.11±0.83) (mg/g) and (5.12±0.87),(3.05±0.87) (mg/mL)and (0.44±0.18),(0.33±0.04) (mg/mL)] were higher than those in the MSC-shcontrol group [(14.88± 1.74),(8.04±l.70)(mg/g) and (8.08±1.72),(5.94±1.20) (mg/mL) and (0.71±0.21),(1.07±0.29) (mg/mL)] (all P＜0.05),so was the relative expression of Occludin protein[(0.79±0.11) vs (0.49±0).19),(P＜0.05)].The levels of IL-1β and IL-6(pg/mL) in BALF in the MSC-shLATS1 group [(60.11±8.58),(101.74±11.55)] was lower than those in the MSC-shcontrol group [(99.26±14.32),(145.54±13.29)] (all P＜0.05),but the levels of IL-10 in BALF in the MSC-shLATS 1 group (316.65±37.88)pg/mL was higher than those in the MSC-shcontrol group (190.83±22.61)pg/mL (P＜0.05).Lung injury scores at 3 and 14 d in the MSC-shLATS1 group [(7.18±1.12),(3.33±0.49)] was lower than those in the MSC-shcontrol group [(9.72±1.45),(5.11±0.86)] (all P＜0.05),so was pulmonary fibrosis score at 14 d [(0.68±0.12) vs (1.47±0.18),P＜0.05].Conclusion Inhibition of Hippo signaling pathway through underexpression of LATS1 could improve the therapeutic effects of mMSCs in murine LPS-induced ARDS.
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[Objective]To investigate the effect of human umbilical cord mesenchymal stem cells on infected state of human alve?olar type Ⅱ epithelial cells.[Methods]Human alveolar type Ⅱ epithelial cells A549(1×105/mL)2 mL and PA(3×104 CFU/mL)2 mL has grown after 6 hours,add hUCMSC(1 × 106/mL)2 mL as the experimental group,add equal amounts of phosphate buffer (PBS)for infection,A549 and PBS and the medium has grown as the control group. A549 cells morphological changes between the compared groups(Transmission electron microscope,TEM),A549 cell viability(new CCK-8 cell proliferation assay Kit),A549 cells apoptosis(Annexin V-FITC/PI double staining flow cytometry)and the expression of A549 pulmonary surfactant A(SP-A) (Western blot).[Results]Transmission electron microscope cell morphology observation displayed ,infection group A549 cell dam?aged obviously,cell quality appeared empty bubble degeneration,chromatin height agglutination,visible apoptosis bodies;experi?ment group cell package film structure full,nuclear film full,nucleolus obviously,nuclear chromatin electronic density low,chroma? tin uniform,no apoptotic bodies;control group A549 cell structure full,membrane surface micro-fluff rich,nuclear film full,nucle?ar week clearance structure normal,chromatin uniform;infection group and control group compared,Infection group A549 cell sur?vival significantly reduced[(70.35±2.89)% and(97.37±2.07)%,n=3,P<0.01],apoptosis rate significantly increased[(8.63%± 0.16)%and(2.55±0.11)%,n=3,P<0.01],In the infected group,PA could damage A549 cells and decrease the amount of SP-A ex?pression(n=5,P<0.05). In the experiment group,the protective effect of hUCMSC on the A549 cells after infection may increase the expression of SP-A(n=5,P<0.05);[Conclusions]HUCMSC inhibits the infection of A549 cells apoptosis and protection of A549 cells secrete SP-A.
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AIM:To investigate the effects of myeloid-related protein 8/14 ( MRP8/14 ) on the survival and apoptosis of human alveolar epithelial cell line A549, and to explore the role of nuclear factor-κB (NF-κB) in this process. METHODS:A549 cells were treated with different doses of MRP8/14 or stimulated with MRP8/14 for different time.The effect of MRP8/14 on the viability of A549 cells was determined by CCK-8 assay.The apoptotic rates were tested by flow cytometry.The nuclear translocation of NF-κB p65 was detected by Western blot and indirect immunofluorescence.Be-sides, the phosphorylation level of NF-κB p65 was determined by Western blot.NF-κB-specific inhibitor Bay 11-7082 was used to further analyze the role of NF-κB in the apoptosis induced by MRP8/14.RESULTS:The viability of the A549 cells was affected by MRP8/14 in a dose-and time-dependent manner.Flow cytometric analysis showed that the apoptotic rates were increased in the cells treated with MRP8/14 (P<0.01).In A549 cells administered with MRP8/14, NF-κB p65 was significantly phosphorylated and translocated into the nuclei, suggesting the activation of NF-κB signaling pathway. However, NF-κB-specific inhibitor Bay 11-7082 significantly attenuated the cell apoptosis induced by MRP8/14 ( P <0.01).CONCLUSION:NF-κB plays an important role in regulating the apoptosis of human alveolar epithelial cells in-duced by MRP8/14.
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Objective To study the protective role of pre-resolving mediator lipoxin A4(LXA4) in the NA+ -K+-ATPase in alveolar type Ⅱ (AT Ⅱ ) epithelial cells of rats exposed to lipopolysaccharide (LPS). Method The AT Ⅱ cells were isolated and purified, and divided randomly into control group (PBS), vehiculum (alcohol 0.7 μL/mL) group, LPS (1 μg/mL) group, LXA4(1/10 mol/mL) group and LPS (1 μg/mL LPS) + LXA4(1/10 mol/mL) group. After exposure to LPS and/or LXA4 for4 hours, NA+-K+ -ATPase and β1-subunits mRNA in AT Ⅱ epithelial cells were detected by using RT-PCR, and ATP, ADP, AMP, total adenine nucleotides (TAN) and energy charge (EC) were measured by using high performance liquid chromatography (HPLC), and then the activities of Na+-K+-ATPase were calculated accordingly. Results The NA+-K+-ATPase α-subunit and β-subunit mRNA were significantly decreased in LPS group ( P ＜ 0.05 vs. control group). However, the expressions of NA+ -K+-ATPase mRNA were significantly enhanced by application of LXA4 to AT Ⅱ epithelial cells exposed to LPS (P ＜0.05 vs. LPS group). The activities of NA+ -K+ -ATPase were enhanced in LPS group (P ＜0.05 vs. control group). Compared with control group and LPS group, the activities of NA+-K+-ATpase in LPS + LXA4 group were significantly increased (P ＜0.01 vs. control group; P ＜0.05 vs. LPS group). The EC of AT Ⅱ epithelial cells were higher in LPS group ( P ＜ 0.01 vs. control group). There were no significant differences in EC between control group and LPS + LXA4group(P ＞0.05). Conclusions The pro-resolving mediator LXA4 can enhance the expressions of NA + -K + -ATPase α-subunit and β-subunit mRNA, and the activities of NA + -K + -ATPase in AT Ⅱ epithelial cells or rats exposed to LPS, and ca also balance the metabolism of AT Ⅱ epithelial cells. These findings suggest that LXA4 plays an important role in lung edema clearance in lung injury induced by endotoxin, and the role is likely associated with the enhancement of the expressions of Na+ -K+ -AT-Pase α-subunit and β-subunit, and the activities of Na+ -K* -ATPase, maintaining the balance of metabolism of AT Ⅱ epithelial cells.
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Objective To investigate the apoptosis response to mechanical stretch in human alveolar type Ⅱ epithelial cells A549.Methods First,A549 cells were given different stretch(0%,5%,15%,30%) at frequency of 0.5 Hz for 4 h.Then,A549 cells were stretched for different periods(0 h,2 h,4 h,8 h) at stretch 15%,0.5 Hz.Last,A549 cells were stretched for different frequency(0 Hz,0.2 Hz,0.5 Hz and 1 Hz) at stretch 15% for 4 h.The early apoptosis was detected by flow cytometry. Results A549 cells submitted to cyclic stretch caused the early apoptosis in a time-,stretch-and frequency-dependent manner.In details,at 0.5 Hz and 4 h stretch-dependence occurred,at 15% stretch and 0.5 Hz time-dependence occurred,and at 15% stretch and 4 h frequency-dependence occurred. Conclusion Mechanical stretch can induce the early apoptosis in human alveolar type Ⅱ epithelial cells A549,which may be one of the mechanisms of ventilator-induced lung injury.
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Objective To study the role of signal transducer and activator of transcription3 (Stat3) in alveolar type Ⅱ epithelial cells (AT-Ⅱ) treated with the serum from rat model of severe acute pancreatitis. Methods AT-Ⅱ cells of primary culture were treated with serum from rat model of severe acute pancreatitis (SAP group),or SAP serum+AG490 (JAK inhibitor),while the normal cell control was set. AT-Ⅱ cells after treatment were collected to determine activation of Stat3 by EMSA,Stat3 mRNA expression by RT-PCR,and surfactant protein C (SP-C) level in AT-Ⅱ cells by flow cytometry. Results Stat3 protein and mRNA levels were enhanced in SAP group (P