scholarly journals Quantitative Proteomic Analysis in Alveolar Type II Cells Reveals the Different Capacities of RAS and TGF-β to Induce Epithelial–Mesenchymal Transition

2021 ◽  
Vol 8 ◽  
Author(s):  
Yilu Zhou ◽  
Charlotte Hill ◽  
Liudi Yao ◽  
Juanjuan Li ◽  
David Hancock ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Proteomic Analysis ◽  
Cancer Metastasis ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Acute Injury ◽  
Alveolar Type ◽  
Type Ii ◽  
Label Free ◽  
Mesenchymal Transition

Alveolar type II (ATII) epithelial cells function as stem cells, contributing to alveolar renewal, repair and cancer. Therefore, they are a highly relevant model for studying a number of lung diseases, including acute injury, fibrosis and cancer, in which signals transduced by RAS and transforming growth factor (TGF)-β play critical roles. To identify downstream molecular events following RAS and/or TGF-β activation, we performed proteomic analysis using a quantitative label-free approach (LC-HDMSE) to provide in-depth proteome coverage and estimates of protein concentration in absolute amounts. Data are available via ProteomeXchange with identifier PXD023720. We chose ATIIER:KRASV12as an experimental cell line in which RAS is activated by adding 4-hydroxytamoxifen (4-OHT). Proteomic analysis of ATII cells treated with 4-OHT or TGF-β demonstrated that RAS activation induces an epithelial–mesenchymal transition (EMT) signature. In contrast, under the same conditions, activation of TGF-β signaling alone only induces a partial EMT. EMT is a dynamic and reversible biological process by which epithelial cells lose their cell polarity and down-regulate cadherin-mediated cell–cell adhesion to gain migratory properties, and is involved in embryonic development, wound healing, fibrosis and cancer metastasis. Thus, these results could help to focus research on the identification of processes that are potentially driving EMT-related human disease.

scholarly journals Mechanism of lipopolysaccharide-mediated induction of epithelial-mesenchymal transition of alveolar type II epithelial cells in absence of other inflammatory cells

2021 ◽  
Vol 19 ◽  
pp. 205873922110144
Author(s):  
Shuai Wu ◽  
Huan Ye ◽  
TianJiao Xue ◽  
Jiali Wang
Keyword(s):  
Epithelial Cells ◽  
Pulmonary Fibrosis ◽  
Epithelial Mesenchymal Transition ◽  
Mesenchymal Cell ◽  
Expression Level ◽  
Alveolar Type ◽  
Type Ii ◽  
Gram Negative ◽  
Mesenchymal Transition ◽  
Tgf Β1

Several studies have shown that gram-negative bacilli infection can cause acute lung injury, and that consequent pulmonary fibrosis is caused when alveolar type-II epithelial cells undergo epithelial-mesenchymal transition (EMT). However, the mechanism underlying this change remains unclear. This study aimed to elucidate whether the main toxin of gram-negative bacteria, lipopolysaccharide (LPS), can induce EMT in human alveolar epithelial cells, and the underlying molecular mechanisms. Human alveolar type-II epithelial cells (A549) were used in EMT induction experiments. Cells were collected after LPS exposure, and changes in the expression levels of epithelial and mesenchymal cell markers were determined. Further, the effect of LPS exposure on the expression of Toll-like Receptor 4 (TLR4), Transforming Growth Factor-beta 1 (TGF-β1) and Smad2/3 was assessed. The expression level of a mesenchymal cell marker was also assessed after pharmacological inhibition of TLR4 and TGF-β1 prior to addition of LPS, to identify downstream pathways involved in EMT induction. Results showed that LPS exposure caused significant downregulation of epithelial marker E-cadherin, and upregulation of mesenchymal marker vimentin, together with increased expression of TGF-β1 and activation of the TGF-β1/Smad2/3 pathway. Furthermore, pretreatment with TGF-β1 and TLR4 inhibitors suppressed EMT, and treatment with the latter also reduced the expression level of TGF-β1. Overall, we conclude that LPS directly induces EMT in A549 cells through upregulation of TLR4 and activation of the TGF-β1/Smad2/3 signalling pathway. Our results suggest that LPS-mediated pulmonary fibrosis may occur in ALI patients even if the LPS-induced inflammatory response is inhibited.

scholarly journals Different macrophages equally induce EMT in endometria of adenomyosis and normal

Reproduction ◽  
2017 ◽  
Vol 154 (1) ◽  
pp. 79-92 ◽  
Author(s):  
Min An ◽  
Dong Li ◽  
Ming Yuan ◽  
Qiuju Li ◽  
Lu Zhang ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Quantitative Polymerase Chain Reaction ◽  
Immunohistochemical Analysis ◽  
Secretory Phase ◽  
Normal Endometrium ◽  
Mesenchymal Transition ◽  
Expression Levels ◽  
Endometrial Cells

Endometrial cells and microenvironment are two important factors in the pathogenesis of adenomyosis. Our previous study demonstrated that macrophages can induce eutopic epithelial cells of adenomyosis to suffer from epithelial–mesenchymal transition (EMT). The aim of this study is to detect whether macrophages interacting with epithelial cells equally induce the EMT process in normal and eutopic endometria of healthy and adenomyotic patients; and whether macrophages parallelly polarize to M2. We investigated the expression levels of epithelial cadherin (E-cadherin), neural cadherin (N-cadherin), cytokeratin7 (CK7), vimentin, transforming growth factor-β1 (TGFB1), SMAD3 and pSMAD3 using immunohistochemistry and western blot, and then estimated the genetic levels of CD163, IL10 and MMP12 using real-time quantitative polymerase chain reaction (RT-PCR) in macrophages. Eutopic and normal endometrial tissues were obtained from 20 patients with adenomyosis and 11 control patients without adenomyosis, respectively. The immunohistochemical analysis shows distinct EMT in eutopic endometria in secretory phase; the expression levels of TGFB1, SMAD3 and pSMAD3 that indicate signal pathway of EMT were also higher in secretory phase. Macrophages can induce EMT process in primary endometrial epithelial cells derived from normal and eutopic endometria. After co-culturing, THP-1-derived macrophages polarized to M2. Compared with the eutopic endometrium group, further polarization to M2 was observed in the normal endometrium group. These results indicate that adenomyosis may be promoted by the pathologic EMT of epithelial cells, which is induced by macrophages that incapably polarize to M2.

scholarly journals The Molecular Mechanism of Epithelial–Mesenchymal Transition for Breast Carcinogenesis

Biomolecules ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 476 ◽  
Author(s):  
Chia-Jung Li ◽  
Pei-Yi Chu ◽  
Giou-Teng Yiang ◽  
Meng-Yu Wu
Keyword(s):  
Epithelial Cells ◽  
Tumor Progression ◽  
Signaling Pathways ◽  
Intracellular Signaling ◽  
Molecular Mechanisms ◽  
Transforming Growth Factor ◽  
Epithelial Mesenchymal Transition ◽  
Transforming Growth Factor Β ◽  
Inhibition Of Proliferation ◽  
Mesenchymal Transition

The transforming growth factor-β (TGF-β) signaling pathway plays multiple regulatory roles in the tumorigenesis and development of cancer. TGF-β can inhibit the growth and proliferation of epithelial cells and induce apoptosis, thereby playing a role in inhibiting breast cancer. Therefore, the loss of response in epithelial cells that leads to the inhibition of cell proliferation due to TGF-β is a landmark event in tumorigenesis. As tumors progress, TGF-β can promote tumor cell invasion, metastasis, and drug resistance. At present, the above-mentioned role of TGF-β is related to the interaction of multiple signaling pathways in the cell, which can attenuate or abolish the inhibition of proliferation and apoptosis-promoting effects of TGF-β and enhance its promotion of tumor progression. This article focuses on the molecular mechanisms through which TGF-β interacts with multiple intracellular signaling pathways in tumor progression and the effects of these interactions on tumorigenesis.

scholarly journals Pathological Study on Epithelial-Mesenchymal Transition in Silicotic Lung Lesions in Rat

2019 ◽  
Vol 6 (3) ◽  
pp. 70 ◽  
Author(s):  
Mao Komai ◽  
Karin Mihira ◽  
Akinori Shimada ◽  
Ikumi Miyamoto ◽  
Kikumi Ogihara ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Pulmonary Fibrosis ◽  
Epithelial Mesenchymal Transition ◽  
Crystalline Silicon ◽  
Interstitial Fibrosis ◽  
Female Rats ◽  
Dependent Manner ◽  
Type Ii ◽  
Mesenchymal Transition ◽  
Spindle Cells

Silicosis, caused by the inhalation of crystalline silicon dioxide or silica, is one of the most severe occupational diseases. Persistent inflammation and progressive massive pulmonary fibrosis are the most common histological changes caused by silicosis. Association of epithelial-mesenchymal transition (EMT) of hyperplastic type II epithelial cells with the fibrotic events of pulmonary fibrosis has been suggested in in vitro silica-exposed cultured cell models, patients with idiopathic pulmonary fibrosis, and bleomycin-induced experimental models. Histological features of EMT, however, are not fully described in silicotic lungs in in vivo. The purpose of this study was to demonstrate EMT of hyperplastic type II epithelial cells in the developmental process of progressive massive pulmonary fibrosis in the lungs of rats exposed to silica. F344 female rats were intratracheally instilled with 20 mg of crystalline silica (Min-U-Sil-5), followed by sacrifice at 1, 3, 6, and 12 months after instillation. Fibrosis, characterized by the formation of silicotic nodules, progressive massive fibrosis, and diffuse interstitial fibrosis, was observed in the lungs of the treated rats; the effects of fibrosis intensified in a time-dependent manner. Hyperplasia of the type II epithelial cells, observed in the massive fibrotic lesions, dominated in the lungs of rats at 6 and 12 months after the treatment. Immunohistochemistry of the serial sections of the lung tissues demonstrated positive labeling for cytokeratin, vimentin, and α-smooth muscle actin in spindle cells close to the foci of hyperplasia of type II epithelial cells. Spindle cells, which exhibited features of both epithelial cells and fibroblasts, were also demonstrated with bundles of collagen fibers in the fibrotic lesions, using electron microscopy. Increased expression of TGF-β was shown by Western blotting and immunohistochemistry in the lungs of the treated rats. These findings suggested that enhanced TGF-β expression and EMT of hyperplastic type II epithelial cells are involved in the development process of progressive massive pulmonary fibrosis during silicosis.

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