STAT3 Promotes Apoptosis of Alveolar Epithelial Cells by Inhibiting AKT Signaling

2021 ◽  
Vol 7 (4) ◽  
pp. 741-748
Author(s):  
Jianhua Liu ◽  
Liqing Zheng ◽  
Liang Cao ◽  
Changhong Zhang ◽  
Chen Li
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Signaling Pathway ◽  
Alveolar Epithelial Cell ◽  
Akt Signaling ◽  
Alveolar Epithelial Cells ◽  
Type Ii ◽  
Akt Signaling Pathway ◽  
Alveolar Epithelial ◽  
Epithelial Cell Apoptosis

Type II alveolar epithelial cells are a crucial component of alveolar epithelium, and transcriptional activator 3 (STAT3) have functions in regulating alveolar epithelial cell proliferation. Therefore, based on the modular approach, we analyzed the effects of silencing STAT3 on type II alveolar epithelial cells and studied its mechanism of action. Initially, in the GEO database, we downloaded data on type II alveolar epithelial cells. For transcript to me data in alveolar epithelial cell samples, we performed a differential analysis. Secondly, protein interaction network analysis (PPIs) were performed on the differential genes, and the PPIs were analyzed modularly. The module gene was subjected to enrichment analysis of GO function and KEGG pathway. Non-coding RNAs and transcription factors that regulate the module are predicted based on hyper geometric testing. Thus, we have a total of 13 dysfunction modules. These modular genes are significantly involved in biological processes such as nuclear membranes, embryonic organ development, and regulate the insulin signaling pathway and the PI3K-Akt signaling pathway substantially. We identified vital ncRNA pivots (miR-205-5p) and TF pivot (Eomes, Etsl, Nfkbl, Spi1, Statl, Usfl) to regulate dysfunction modules significantly. Our work deciphered a co-expression network that involved essential gene regulation of type II alveolar epithelial cell apoptosis. It helps to reveal the regulation of silencing STAT3 gene on alveolar epithelial cell apoptosis and deepen our understanding of the mechanism. More importantly, we explained that the silencing gene STAT3 inhibits the apoptosis of alveolar epithelial cells by activating the AKT signaling pathway, providing a new theoretical reference for the study of alveolar epithelial cells.

Effect of cigarette smoke and its condensates on alveolar epithelial cell injury in vitro

1994 ◽  
Vol 266 (1) ◽  
pp. L92-L100 ◽  
Author(s):  
S. Lannan ◽  
K. Donaldson ◽  
D. Brown ◽  
W. MacNee
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cigarette Smoke ◽  
Cell Injury ◽  
Cell Attachment ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Type Ii ◽  
Alveolar Epithelial

The oxidant-antioxidant balance in the airspaces of the lungs may be critical in protecting the lungs from the effects of cigarette smoke. We studied the effect of cigarette smoke and its condensates on the detachment, attachment, and proliferation of the A549 human alveolar epithelial cell line, in an in vitro model of cell injury and regeneration and the protective effects of antioxidants. Whole and vapor phase cigarette smoke decreased 51Cr-labeled A549 cell attachment, increased cell detachment, and decreased cell proliferation, as assessed by [3H]thymidine uptake. Freshly isolated rat type II alveolar epithelial cells showed an enhanced susceptibility to smoke-induced cell lysis when compared with the A549 cell line. Reduced glutathione (GSH) (400 microM) protected against the effects of cigarette smoke exposure on cell attachment, proliferation, and detachment. Depletion of intracellular GSH with buthionine sulfoxamine enhanced the epithelial cell detachment injury produced by smoke condensates. We conclude that cigarette smoke and its condensates cause an oxidant-induced injury to A549 human type II alveolar epithelial cells. Both intra- and extracellular GSH have important roles in protecting epithelial cells from the injurious effects of cigarette smoke.

Association of ICAM-1 with the cytoskeleton in rat alveolar epithelial cells in primary culture

1996 ◽  
Vol 271 (5) ◽  
pp. L707-L718 ◽  
Author(s):  
W. W. Barton ◽  
S. E. Wilcoxen ◽  
P. J. Christensen ◽  
R. Paine
Keyword(s):  
Endothelial Cells ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Alveolar Epithelial Cell ◽  
Inflammatory Cells ◽  
Alveolar Epithelial Cells ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Epithelial

Intercellular adhesion molecule-1 ICAM-1) is a transmembrane adhesion protein that is expressed constitutively on the apical surface of type I cells in vivo and on type II cells in vitro as they spread in culture, assuming type I cell-like characteristics. To investigate the possible interaction of ICAM-1 with the alveolar epithelial cell cytoskeleton, rat type II cells in primary culture were extracted with nonionic detergent, and residual ICAM-1 associated with the cytoskeletal remnants was determined using immunofluorescence microscopy, immunoprecipitation, and cell-based enzyme-linked immunosorbent assay. A large fraction of alveolar epithelial cell ICAM-1 remained associated with the cytoskeleton after detergent extraction, whereas two other transmembrane molecules, transferrin receptor and class II major histocompatibility complex, were completely removed. ICAM-1 was redistributed on the cell surface after the disruption of actin filaments with cytochalasin B, suggesting interaction with the actin cytoskeleton. In contrast, ICAM-1 was completely detergent soluble in rat pulmonary artery endothelial cells, human umbilical vein endothelial cells, and rat alveolar macrophages. The association of ICAM-1 with the alveolar epithelial cell cytoskeleton was not altered after stimulation with inflammatory cytokines. However, detergent resistant ICAM-1 was significantly increased after crosslinking of ICAM-1 on the cell surface, suggesting that this cytoskeletal association may be modulated by interactions of alveolar epithelial cells with inflammatory cells. The association of ICAM-1 with the cytoskeleton in alveolar epithelial cells may provide a fixed intermediary between mobile inflammatory cells and the alveolar surface.

Regulation of type II alveolar epithelial cell proliferation by TGF-beta during bleomycin-induced lung injury in rats

1994 ◽  
Vol 267 (5) ◽  
pp. L498-L507 ◽  
Author(s):  
N. Khalil ◽  
R. N. O'Connor ◽  
K. C. Flanders ◽  
W. Shing ◽  
C. I. Whitman
Keyword(s):  
Cell Proliferation ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Type Ii ◽  
Epithelial Cell Proliferation ◽  
Tgf Beta ◽  
Alveolar Epithelial

Three isoforms of transforming growth factor-beta (TGF-beta) are found in mammalian cells and are potent regulators of inflammation, connective tissue synthesis, cellular proliferation, and differentiation. To determine the distribution and regulation of TGF-beta isoforms during pulmonary injury, a rat model of bleomycin-induced lung inflammation and repair was used. Using immunohistochemistry, we demonstrate that TGF-beta 2 and TGF-beta 3 were localized to alveolar macrophages as well as epithelial and smooth muscle cells of both normal rat lungs and rat lungs obtained at all time intervals after bleomycin administration. Early in bleomycin-induced lung injury, when there is active proliferation of type II alveolar epithelial cells, there was an increase in the number of type II alveolar epithelial cells isolated per lung and an increase in DNA synthesis by explanted type II alveolar epithelial cells. At this time, the secretion of biologically active TGF-beta 1–3, which are potent inhibitors of epithelial cell proliferation, was decreased. However, the secretion of TGF-beta 1–3 activity was markedly increased later in the injury response and coincided with a reduction in the number of type II alveolar epithelial cells isolated per lung and DNA synthesis in vitro. Furthermore, the addition of TGF-beta 1, 2, and 3 to cultures of actively proliferating type II alveolar epithelial cells resulted in inhibition of [3H]thymidine incorporation, whereas, in the presence of anti-TGF-beta 1-3 antibody, there was an increase in [3H]thymidine incorporation. Our findings suggest that altered secretion of TGF-beta 1-3 activity by type II alveolar epithelial cells during bleomycin-induced lung injury may regulate pulmonary alveolar epithelial cell proliferation during injury and repair phases.

scholarly journals Long non-coding RNA MALAT1 protects epithelial cells from LPS-induced acute lung injury by regulating miRNA-181a-3p /B

2020 ◽  
Author(s):  
Yaling Liu ◽  
Xiaodong Wang ◽  
Liqun Yang ◽  
Hong Xie
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Apoptosis ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Alveolar Epithelial ◽  
Non Coding Rna ◽  
Tnf Α ◽  
Epithelial Cell Apoptosis ◽  
Long Non Coding Rna

Abstract Background Long non-coding RNA metastasis-associated lung adenocarcinoma transcript-1 (MALAT1) plays an important role in the pathophysiological process of inflammation. We aimed to investigate MALAT1 and its function in modulating miRNA-181a-3p and Bcl-2 in lipopolysaccharide (LPS)-induced acute lung injury (ALI). Methods We analysed MALAT1 in ALI patients, as well as the alveolar epithelial cell models of LPS-induced injury. The expression of MALAT1 and miRNA-181a-3p were evaluated by qRT-PCR, and Bcl-2 was measured by western blot. Inflammatory factors tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 mRNA levels were also quantified by qRT-PCR. Luciferase reporter assay was used to verify direct interaction between MALAT1 and miRNA-181a-3p, or miRNA-181a-3p and Bcl-2. Transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) assay was performed to detect alveolar epithelial cell apoptosis. Results Serum MALAT1 and Bcl-2 levels decreased in ALI patients, whereas miRNA-181a-3p, TNF-α, IL-1β and IL-6 levels increased (P<0.01). MALAT1 was inversely correlated to miRNA-181a-3p (R=-0.508, P=0.0031) in ALI patients. SiMALAT1 transfection upregulated miRNA-181a-3p level and downregulated Bcl-2 expression, aggravating alveolar epithelial cell apoptosis. MiRNA-181a-3p downregulated the Bcl-2 expression both in LPS-induced ALI rats and alveolar epithelial cells, as well as promoted apoptosis. TNF-α, IL-1β and IL-6 levels increased after LPS stimulation and siMALAT1 transfection. Conclusions The results demonstrate that LPS-induced ALI decreases lncRNA MALAT1, increases miRNA-181a-3p and inflammatory factor expression, downregulates the Bcl-2 level and promotes alveolar epithelial cell apoptosis. Down-regulation of MALAT1 may erase the protection of alveolar epithelial cells from LPS-induced ALI via up-regulating of miRNA-181a-3p.

scholarly journals Senescence associated long non-coding RNA 1 regulates cigarette smoke-induced senescence of type II alveolar epithelial cells through sirtuin-1 signaling

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098604
Author(s):  
Dong Yuan ◽  
Yuanshun Liu ◽  
Mengyu Li ◽  
Hongbin Zhou ◽  
Liming Cao ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cigarette Smoke ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Sirtuin 1 ◽  
Type Ii ◽  
Alveolar Epithelial ◽  
Non Coding Rna ◽  
Long Non Coding Rna

Objective The primary aim of our study was to explore the mechanisms through which long non-coding RNA (lncRNA)-mediated sirtuin-1 (SIRT1) signaling regulates type II alveolar epithelial cell (AECII) senescence induced by a cigarette smoke-media suspension (CSM). Methods Pharmacological SIRT1 activation was induced using SRT2104 and senescence-associated lncRNA 1 (SAL-RNA1) was overexpressed. The expression of SIRT1, FOXO3a, p53, p21, MMP-9, and TIMP-1 in different groups was detected by qRT-PCR and Western blotting; the activity of SA-β gal was detected by staining; the binding of SIRT1 to FOXO3a and p53 gene transcription promoters was detected by Chip. Results We found that CSM increased AECII senescence, while SAL-RNA1 overexpression and SIRT1 activation significantly decreased levels of AECII senescence induced by CSM. Using chromatin immunoprecipitation, we found that SIRT1 bound differentially to transcriptional complexes on the FOXO3a and p53 promoters. Conclusion Our results suggested that lncRNA-SAL1-mediated SIRT1 signaling reduces senescence of AECIIs induced by CSM. These findings suggest a new therapeutic target to limit the irreversible apoptosis of lung epithelial cells in COPD patients.

Protective effect of IL-6 on alveolar epithelial cell death induced by hydrogen peroxide

2005 ◽  
Vol 288 (2) ◽  
pp. L342-L349 ◽  
Author(s):  
Hiroshi Kida ◽  
Mitsuhiro Yoshida ◽  
Shigenori Hoshino ◽  
Koji Inoue ◽  
Yukihiro Yano ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Lung Fibroblasts ◽  
Alveolar Epithelial ◽  
Epithelial Cell Death

The goal of this study was to examine whether IL-6 could directly protect lung resident cells, especially alveolar epithelial cells, from reactive oxygen species (ROS)-induced cell death. ROS induced IL-6 gene expression in organotypic lung slices of wild-type (WT) mice. ROS also induced IL-6 gene expression in mouse primary lung fibroblasts, dose dependently. The organotypic lung slices of WT were more resistant to ROS-induced DNA fragmentation than those of IL-6-deficient (IL-6−/−) mice. WT resistance against ROS was abrogated by treatment with anti-IL-6 antibody. TdT-mediated dUTP nick end labeling stain and electron microscopy revealed that DNA fragmented cells in the IL-6−/− slice included alveolar epithelial cells and endothelial cells. In vitro studies demonstrated that IL-6 reduced ROS-induced A549 alveolar epithelial cell death. Together, these data suggest that IL-6 played an antioxidant role in the lung by protecting lung resident cells, especially alveolar epithelial cells, from ROS-induced cell death.

Injury of rat pulmonary alveolar epithelial cells by H2O2: dependence on phenotype and catalase

1991 ◽  
Vol 260 (4) ◽  
pp. L318-L325 ◽  
Author(s):  
R. H. Simon ◽  
J. A. Edwards ◽  
M. M. Reza ◽  
R. G. Kunkel
Keyword(s):  
Epithelial Cells ◽  
Catalase Activity ◽  
Lung Diseases ◽  
Alveolar Epithelial Cell ◽  
Alveolar Epithelial Cells ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Epithelial

In a variety of inflammatory lung diseases, type I alveolar epithelial cells are more likely to be injured than are type II cells. Because oxidants have been implicated as a cause of injury in various inflammatory lung diseases, we evaluated the effects of differentiation on alveolar epithelial cell susceptibility to H2O2-induced injury. With the use of isolated rat type II cells in culture, we found that the cytotoxic effect of H2O2 increased between days 2 and 7, when type II cells are known to lose their distinctive type II properties and assume a more type I-like appearance. We previously reported that type II cells utilized both intracellular catalase and glutathione-dependent reactions to protect against H2O2. We therefore examined whether alterations in either of these protective mechanisms were responsible for the differentiation-dependent changes in sensitivity to H2O2. We found that catalase activity within alveolar epithelial cells decreased between 2 and 7 days in culture, whereas no changes were detected in glutathione-dependent systems. We then used a histochemical technique that detects catalase activity and found that type II cells within rat lungs possessed numerous catalase-containing peroxisomes, whereas very few were detected in type I cells. These findings demonstrate that as type II cells assume a type I-like phenotype, they become more susceptible to H2O2-induced injury. This increased susceptibility is associated with reductions in intracellular catalase activity, both in vitro and in vivo.

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