scholarly journals Airway Basal Cells Mediate Hypoxia-Induced EMT by Increasing Ribosome Biogenesis

2021 ◽  
Vol 12 ◽  
Author(s):  
Yapeng Hou ◽  
Yan Ding ◽  
Danni Du ◽  
Tong Yu ◽  
Wei Zhou ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Epithelial Cells ◽  
Airway Epithelium ◽  
Ribosome Biogenesis ◽  
Liquid Interface ◽  
Basal Cells ◽  
Data Set ◽  
Mesenchymal Transition ◽  
Primary Mouse ◽  
Cell Hypoxia

Excessive secretion of airway mucus and fluid accumulation are the common features of many respiratory diseases, which, in turn, induce cell hypoxia in the airway epithelium, resulting in epithelial–mesenchymal transition (EMT) and ultimately fibrosis. However, the mechanisms of EMT induced by hypoxia in the airway are currently unclear. To mimic the status of edematous fluid retention in the airway, we cultured primary mouse tracheal epithelial cells (MTECs) in a liquid–liquid interface (LLI) mode after full differentiation in a classic air–liquid interface (ALI) culture system. The cell hypoxia was verified by the physical characteristics and lactate production in cultured medium as well as HIF expression in MTECs cultured by LLI mode. EMT was evidenced and mainly mediated by basal cells, supported by flow cytometry and immunofluorescence assay. The differently expressed genes of basal and other airway epithelial cells were found to be enriched in the ribosome by our analysis of an MTEC single-cell RNA sequencing data set and Myc, the global regulator of ribosome biogenesis was identified to be highly expressed in basal cells. We next separated basal cells from bulk MTECs by flow cytometry, and the real-time PCR results showed that ribosome biogenesis was significantly upregulated in basal cells, whereas the inhibition of ribosome biogenesis alleviated the phosphorylation of the mammalian target of rapamycin/AKT and abrogated hypoxia-induced EMT in MTECs. Collectively, these observations strongly suggest that basal cells in the airway epithelium may mediate the process of hypoxia-induced EMT, partly through enhancing ribosome biogenesis.

scholarly journals Effect of Alpha-1 Antitrypsin on CFTR Levels in Primary Human Airway Epithelial Cells Grown at the Air-Liquid-Interface

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2639
Author(s):  
Frauke Stanke ◽  
Sabina Janciauskiene ◽  
Stephanie Tamm ◽  
Sabine Wrenger ◽  
Ellen Luise Raddatz ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Lung ◽  
Liquid Interface ◽  
Lung Epithelial Cells ◽  
Western Blots ◽  
Mesenchymal Transition ◽  
Protein Levels ◽  
Lung Epithelial ◽  
Cftr Protein ◽  
Air Liquid Interface

The cystic fibrosis transmembrane conductance regulator (CFTR) gene is influenced by the fundamental cellular processes like epithelial differentiation/polarization, regeneration and epithelial–mesenchymal transition. Defects in CFTR protein levels and/or function lead to decreased airway surface liquid layer facilitating microbial colonization and inflammation. The SERPINA1 gene, encoding alpha1-antitrypsin (AAT) protein, is one of the genes implicated in CF, however it remains unknown whether AAT has any influence on CFTR levels. In this study we assessed CFTR protein levels in primary human lung epithelial cells grown at the air-liquid-interface (ALI) alone or pre-incubated with AAT by Western blots and immunohistochemistry. Histological analysis of ALI inserts revealed CFTR- and AAT-positive cells but no AAT-CFTR co-localization. When 0.5 mg/mL of AAT was added to apical or basolateral compartments of pro-inflammatory activated ALI cultures, CFTR levels increased relative to activated ALIs. This finding suggests that AAT is CFTR-modulating protein, albeit its effects may depend on the concentration and the route of administration. Human lung epithelial ALI cultures provide a useful tool for studies in detail how AAT or other pharmaceuticals affect the levels and activity of CFTR.

scholarly journals Identification of a basal stem cell subpopulation in the prostate via functional, lineage tracing and single-cell RNA-seq analyses

2019 ◽  
Author(s):  
Xue Wang ◽  
Haibo Xu ◽  
Chaping Cheng ◽  
Zhongzhong Ji ◽  
Huifang Zhao ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Epithelial Cells ◽  
Single Cell ◽  
Basal Cell ◽  
Lineage Tracing ◽  
Cell Subpopulation ◽  
Basal Cells ◽  
Mesenchymal Transition ◽  
Genetic Ablation

AbstractThe basal cell compartment in many epithelial tissues such as the prostate, bladder, and mammary gland are generally believed to serve as an important pool of stem cells. However, basal cells are heterogenous and the stem cell subpopulation within basal cells is not well elucidated. Here we uncover that the core epithelial-to-mesenchymal transition (EMT) inducer Zeb is exclusively expressed in a prostate basal cell subpopulation based on both immunocytochemical and cell lineage tracing analysis. The Zeb1+prostate epithelial cells are multipotent prostate basal stem cells (PBSCs) that can self-renew and generate functional prostatic glandular structures with all three epithelial cell types at the single-cell level. Genetic ablation studies reveal an indispensable role for Zeb1 in prostate basal cell development. Utilizing unbiased single cell transcriptomic analysis of over 9000 mouse prostate basal cells, we find that Zeb1+basal cell subset shares gene expression signatures with both epithelial and mesenchymal cells and stands out uniquely among all the basal cell clusters. Moreover, Zeb1+epithelial cells can be detected in mouse and clinical samples of prostate tumors. Identification of the PBSC and its transcriptome profile is crucial to advance our understanding of prostate development and tumorigenesis.

scholarly journals Altered Epithelial-mesenchymal Plasticity as a Result of Ovol2 Deletion Minimally Impacts the Self-renewal of Adult Mammary Basal Epithelial Cells

2022 ◽  
Author(s):  
Peng Sun ◽  
Yingying Han ◽  
Maksim Plikus ◽  
Xing Dai
Keyword(s):  
Epithelial Cells ◽  
Basal Cell ◽  
Epithelial To Mesenchymal Transition ◽  
Basal Cells ◽  
Self Renewal ◽  
Mesenchymal Transition ◽  
Transcriptional State ◽  
Specific Deletion ◽  
Basal Epithelial Cells

AbstractStem-cell containing mammary basal epithelial cells exist in a quasi-mesenchymal transcriptional state characterized by simultaneous expression of typical epithelial genes and typical mesenchymal genes. Whether robust maintenance of such a transcriptional state is required for adult basal stem cells to fuel self-renewal and regeneration remains unclear. In this work, we utilized SMA-CreER to direct efficient basal cell-specific deletion of Ovol2, which encodes a transcription factor that inhibits epithelial-to-mesenchymal transition (EMT), in adult mammary gland. We identified a basal cell-intrinsic role of Ovol2 in promoting epithelial, and suppressing mesenchymal, molecular traits. Interestingly, Ovol2-deficient basal cells display minimal perturbations in their ability to support tissue homeostasis, colony formation, and transplant outgrowth. These findings underscore the ability of adult mammary basal cells to tolerate molecular perturbations associated with altered epithelia-mesenchymal plasticity without drastically compromising their self-renewal potential.

scholarly journals Cell Wall-associated Protein A as a Tool for Immunolocalization of Staphylococcus aureus in Infected Human Airway Epithelium

2000 ◽  
Vol 48 (4) ◽  
pp. 523-533 ◽  
Author(s):  
Emmanuel Mongodin ◽  
Odile Bajolet ◽  
Jocelyne Hinnrasky ◽  
Edith Puchelle ◽  
Sophie de Bentzmann
Keyword(s):  
Electron Microscopy ◽  
Staphylococcus Aureus ◽  
Epithelial Cells ◽  
Airway Epithelium ◽  
Protein A ◽  
Staphylococcal Protein A ◽  
Basal Cells ◽  
Bronchial Diseases

Staphylococcus aureus is a common human pathogen involved in non-bronchial diseases and in genetic and acquired bronchial diseases. In this study, we applied an immunolabeling approach for in vivo and in vitro detection of S. aureus, based on the affinity of staphylococcal protein A (SpA) for the Fc region of immunoglobulins, especially IgG. Most strains of S. aureus, including clinical strains, can be detected with this labeling technique. The approach can be used for detection and localization with transmission electron microscopy or light-fluorescence microscopy of S. aureus in infected tissues such as human bronchial tissue from cystic fibrosis (CF) patients. The methodology can also be applied to cell culture models with the aim of characterizing bacterial adherence to epithelial cells in backscattered electron imaging with scanning electron microscopy. Application to the study of S. aureus adherence to airway epithelium showed that the bacteria did not adhere in vivo to intact airway epithelium. In contrast, bacteria adhered to the basolateral plasma membrane of columnar cells, to basal cells, to the basement membrane and were identified beneath the lamina propria when the epithelium was injured and remodeled, or in vitro when the epithelial cells were dedifferentiated.

scholarly journals The FOXA1 transcriptional network coordinates key functions of primary human airway epithelial cells

2020 ◽  
Vol 319 (1) ◽  
pp. L126-L136
Author(s):  
Alekh Paranjapye ◽  
Michael J. Mutolo ◽  
Jey Sabith Ebron ◽  
Shih-Hsing Leir ◽  
Ann Harris
Keyword(s):  
Transcription Factors ◽  
Epithelial Cells ◽  
Airway Epithelium ◽  
Epithelial To Mesenchymal Transition ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Mesenchymal Transition ◽  
Human Airway ◽  
Human Airway Epithelium ◽  
Two Factors

The differentiated functions of the human airway epithelium are coordinated by a complex network of transcription factors. These include the pioneer factors Forkhead box A1 and A2 (FOXA1 and FOXA2), which are well studied in several tissues, but their role in airway epithelial cells is poorly characterized. Here, we define the cistrome of FOXA1 and FOXA2 in primary human bronchial epithelial (HBE) cells by chromatin immunoprecipitation with deep-sequencing (ChIP-seq). Next, siRNA-mediated depletion of each factor is used to investigate their transcriptome by RNA-seq. We found that, as predicted from their DNA-binding motifs, genome-wide occupancy of the two factors showed substantial overlap; however, their global impact on gene expression differed. FOXA1 is an abundant transcript in HBE cells, while FOXA2 is expressed at low levels, and both these factors likely exhibit autoregulation and cross-regulation. FOXA1 regulated loci are involved in cell adhesion and the maintenance of epithelial cell identity, particularly through repression of genes associated with epithelial to mesenchymal transition (EMT). FOXA1 also directly targets other transcription factors with a known role in the airway epithelium such as SAM-pointed domain-containing Ets-like factor (SPDEF). The intersection of the cistrome and transcriptome for FOXA1 revealed enrichment of genes involved in epithelial development and tissue morphogenesis. Moreover, depletion of FOXA1 was shown to reduce the transepithelial resistance of HBE cells, confirming the role of this factor in maintaining epithelial barrier integrity.

scholarly journals SOX21 modulates SOX2-initiated differentiation of epithelial cells in the extrapulmonary airways

2020 ◽  
Author(s):  
Evelien Eenjes ◽  
Marjon Buscop-van Kempen ◽  
Anne Boerema-de Munck ◽  
Lisette de Kreij-de Bruin ◽  
J. Marco Schnater ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Progenitor Cells ◽  
Airway Epithelium ◽  
Lung Development ◽  
Fetal Lung ◽  
Basal Cells ◽  
Induced Differentiation ◽  
Bronchial Epithelial ◽  
Sox2 Expression ◽  
Submucosal Glands

ABSTRACTSOX2 expression levels are crucial for the balance between maintenance and differentiation of airway progenitor cells during development and regeneration. Here, we describe SOX21 patterning of the proximal airway epithelium which coincides with high levels of SOX2. Airway progenitor cells in this SOX2+/SOX21+ zone show differentiation to basal cells, specifying cells for the extrapulmonary airways. We show that loss of SOX21 results in increased differentiation of progenitor cells during murine lung development. SOX21 inhibits SOX2-induced differentiation by antagonizing SOX2 binding on different promotors. SOX21 remains expressed in adult tracheal epithelium and submucosal glands, where SOX21 modulates SOX2-induced differentiation in a similar fashion. Using fetal lung organoids and adult bronchial epithelial cells, we show that SOX2+SOX21+ regionalization is conserved in human. Thus SOX21 modulates SOX2-initiated differentiation in extrapulmonary epithelial cells during development and regeneration after injury.

scholarly journals SOX21 modulates SOX2-initiated differentiation of epithelial cells in the extrapulmonary airways

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Evelien Eenjes ◽  
Marjon Buscop-van Kempen ◽  
Anne Boerema-de Munck ◽  
Gabriela G Edel ◽  
Floor Benthem ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Progenitor Cells ◽  
Airway Epithelium ◽  
Ciliated Cell ◽  
Fetal Lung ◽  
Mouse Lung ◽  
Basal Cells ◽  
Bronchial Epithelial ◽  
Sox2 Expression ◽  
Human Fetal Lung

SOX2 expression levels are crucial for the balance between maintenance and differentiation of airway progenitor cells during development and regeneration. Here, we describe patterning of the mouse proximal airway epithelium by SOX21, which coincides with high levels of SOX2 during development. Airway progenitor cells in this SOX2+/SOX21+ zone show differentiation to basal cells, specifying cells for the extrapulmonary airways. Loss of SOX21 showed an increased differentiation of SOX2+ progenitor cells to basal and ciliated cells during mouse lung development. We propose a mechanism where SOX21 inhibits differentiation of airway progenitors by antagonizing SOX2-induced expression of specific genes involved in airway differentiation. Additionally, in the adult tracheal epithelium SOX21 inhibits basal to ciliated cell differentiation. This suppressing function of SOX21 on differentiation contrasts SOX2, which mainly drives differentiation of epithelial cells during development and regeneration after injury. Furthermore, using human fetal lung organoids and adult bronchial epithelial cells, we show that SOX2+/SOX21+ regionalization is conserved. Lastly, we show that the interplay between SOX2 and SOX21 is context and concentration dependent leading to regulation of differentiation of the airway epithelium.

scholarly journals Temporal differentiation of bovine airway epithelial cells grown at an air-liquid interface

2017 ◽  
Author(s):  
Daniel Cozens ◽  
Erin Sutherland ◽  
Francesco Marchesi ◽  
Geraldine Taylor ◽  
Catherine Berry ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Ex Vivo ◽  
Animal Health ◽  
Bronchial Epithelium ◽  
Airway Epithelial Cells ◽  
Liquid Interface ◽  
Mucosal Barrier ◽  
Basal Cells ◽  
Airway Epithelial ◽  
Air Liquid Interface

AbstractThe respiratory epithelium is exposed to assault by toxins and pathogens through the process of inhalation, which has numerous implications on both human and animal health. As such, there is a need to develop and characterise anin vitromodel of the airway epithelium to study respiratory pathologies during infection or toxicology experiments. This has been achieved by growing airway epithelial cells at an air-liquid interface (ALI). Characterisation of ALI models are not well-defined for airway epithelial cells derived from non-human species. In this study we have fully characterised a bovine airway epithelial cell models (AECM) grown at an ALI in relation toex vivotissue. The morphology of the model was monitored at three day intervals, to identify the time-period at which the culture was optimally differentiated. The model was shown to be fully-differentiated by day 21 post-ALI. The culture formed a stereotypical pseudostratified, columnar epithelium containing the major cell types of the bronchial epithelium (ciliated-, goblet- and basal cells). Once fully differentiated the bovine AECM displayed both barrier function, through the formation of tight-junctions, and active mucociliary clearance, important properties of the mucosal barrier. The bovine bronchial epithelial cells remained stable for three weeks, with no evidence of deterioration or dedifferentiation. The window in which the model displayed full differentiation was determined to be between day 21-42 post-ALI. Through comparison withex vivotissue derived from donor animals, our bovine AECM was shown to be highly representative of thein vivobovine bronchial epithelium and can be utilised in the study of respiratory pathologies.

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