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 ◽  
...  

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.

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Evelien Eenjes ◽  
Marjon Buscop-van Kempen ◽  
Anne Boerema-de Munck ◽  
Gabriela G Edel ◽  
Floor Benthem ◽  
...  

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.


2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Shakir Hasan ◽  
Nikhil Nitin Kulkarni ◽  
Arni Asbjarnarson ◽  
Irena Linhartova ◽  
Radim Osicka ◽  
...  

ABSTRACTThe airway epithelium restricts the penetration of inhaled pathogens into the underlying tissue and plays a crucial role in the innate immune defense against respiratory infections. The whooping cough agent,Bordetella pertussis, adheres to ciliated cells of the human airway epithelium and subverts its defense functions through the action of secreted toxins and other virulence factors. We examined the impact ofB. pertussisinfection and of adenylate cyclase toxin-hemolysin (CyaA) action on the functional integrity of human bronchial epithelial cells cultured at the air-liquid interface (ALI).B. pertussisadhesion to the apical surface of polarized pseudostratified VA10 cell layers provoked a disruption of tight junctions and caused a drop in transepithelial electrical resistance (TEER). The reduction of TEER depended on the capacity of the secreted CyaA toxin to elicit cAMP signaling in epithelial cells through its adenylyl cyclase enzyme activity. Both purified CyaA and cAMP-signaling drugs triggered a decrease in the TEER of VA10 cell layers. Toxin-produced cAMP signaling caused actin cytoskeleton rearrangement and induced mucin 5AC production and interleukin-6 (IL-6) secretion, while it inhibited the IL-17A-induced secretion of the IL-8 chemokine and of the antimicrobial peptide beta-defensin 2. These results indicate that CyaA toxin activity compromises the barrier and innate immune functions ofBordetella-infected airway epithelia.


2020 ◽  
Vol 55 (6) ◽  
pp. 1901200 ◽  
Author(s):  
Nick J.I. Hamilton ◽  
Dani Do Hyang Lee ◽  
Kate H.C. Gowers ◽  
Colin R. Butler ◽  
Elizabeth F. Maughan ◽  
...  

Current methods to replace damaged upper airway epithelium with exogenous cells are limited. Existing strategies use grafts that lack mucociliary function, leading to infection and the retention of secretions and keratin debris. Strategies that regenerate airway epithelium with mucociliary function are clearly desirable and would enable new treatments for complex airway disease.Here, we investigated the influence of the extracellular matrix (ECM) on airway epithelial cell adherence, proliferation and mucociliary function in the context of bioengineered mucosal grafts. In vitro, primary human bronchial epithelial cells (HBECs) adhered most readily to collagen IV. Biological, biomimetic and synthetic scaffolds were compared in terms of their ECM protein content and airway epithelial cell adherence.Collagen IV and laminin were preserved on the surface of decellularised dermis and epithelial cell attachment to decellularised dermis was greater than to the biomimetic or synthetic alternatives tested. Blocking epithelial integrin α2 led to decreased adherence to collagen IV and to decellularised dermis scaffolds. At air–liquid interface (ALI), bronchial epithelial cells cultured on decellularised dermis scaffolds formed a differentiated respiratory epithelium with mucociliary function. Using in vivo chick chorioallantoic membrane (CAM), rabbit airway and immunocompromised mouse models, we showed short-term preservation of the cell layer following transplantation.Our results demonstrate the feasibility of generating HBEC grafts on clinically applicable decellularised dermis scaffolds and identify matrix proteins and integrins important for this process. The long-term survivability of pre-differentiated epithelia and the relative merits of this approach against transplanting basal cells should be assessed further in pre-clinical airway transplantation models.


2000 ◽  
Vol 48 (4) ◽  
pp. 535-544 ◽  
Author(s):  
Peter H. Michelson ◽  
Margaret Tigue ◽  
Jonathan C.R. Jones

Epithelial cells attach to the basement membrane through adhesive contacts between the basal cells of the epithelium and the proteins of the extracellular matrix (ECM). The hemidesmosome (HD) is a specialized cell-ECM contact, that mediates the attachment of the epithelial cell basal surface to the ECM. In bronchial epithelial cells, the protein components that constitute the HD have not been demonstrated. Using immunohistochemical techniques, we determined that normal human bronchial epithelial (NHBE) cells express the HD cell surface integrin α6β4 and produce laminin 5, the ECM protein associated with HDs. Furthermore, expression of the HD-associated structural proteins, bullous pemphigoid antigens 1 (BPAG 1) and 2 (BPAG 2), was demonstrated in NHBE cells by immunofluorescence microscopy and immunoblot analyses. In addition, we confirmed the presence of laminin 5 in the basement membrane (BM) of bronchial epithelial biopsy specimens and of BP230, BP180, and the α6β4 integrin heterodimer at the site of bronchial epithelial cell-ECM interaction in vivo. Finally, using electron microscopy, we were able to demonstrate intact HDs in a glutaraldehyde-fixed NHBE cell monolayer. These findings suggest that bronchial epithelium forms HDs and that the laminin 5-α6β4 integrin interaction may be important in stabilizing epithelial cell adhesion to the BM in the lung.


1997 ◽  
Vol 155 (2) ◽  
pp. 313-327 ◽  
Author(s):  
LD Wallen ◽  
W Myint ◽  
K Nygard ◽  
S Shimasaki ◽  
DR Clemmons ◽  
...  

A role for IGF binding proteins (IGFBPs) in lung development is suggested by the identification of IGFBPs in lung tissue and production of IGFBPs by fetal lung cells in culture. To characterize the expression of IGFBPs during lung development in the rat in vivo (16 days gestation through adulthood), the expression of IGFBP mRNAs (IGFBP-1 to IGFBP-6) was examined by Northern analysis and in situ hybridization, and IGFBP peptides (IGFBP-2, IGFBP-3, and IGFBP-5) were localized by immunohistochemistry. IGFBP-1 mRNA was not detectable. IGFBP-2 mRNA (1.8 kb) was expressed in both fetal and postnatal life with peak expression during the fetal pseudoglandular stage. IGFBP-2 mRNA was localized mainly to airway epithelium. IGFBP-3 mRNA (2.4 kb) was maximally expressed postnatally in the saccular stage of lung development; it was identified in airway epithelium and interstitium in the fetal lung, but predominantly in airway epithelium after birth. IGFBP-4 (2.6 kb) and IGFBP-5 (6.0 kb) mRNA levels were maximal after birth, from 3 to 21 days postnatal (saccular and alveolar stage). IGFBP-4 mRNA was localized primarily to the interstitium and blood vessels early in development, but was abundant in airway epithelium in the adult. IGFBP-5 mRNA was most abundant in the airway epithelium. IGFBP-3, IGFBP-4, IGFBP-5, and to a lesser extent IGFBP-6 were localized to the large cartilaginous airways in the adult. IGFBP-2, IGFBP-3, and IGFBP-5 peptides were distributed more widely than their respective mRNAs, with a temporal pattern of immunoreactivity following that of their mRNAs. Maximal staining was noted in airway epithelium for IGFBP-2 in the newborn, for IGFBP-3 in the saccular stage (newborn to 3 days postnatal), and for IGFBP-5 in the alveolar stage (5 to 21 days postnatal). Our studies demonstrate that IGFBP-2, IGFBP-3, IGFBP-4, and IGFBP-5 are synthesized and distributed in spatially and temporally different patterns in the developing lung. The widespread distribution of IGFBP immunoreactivity compared with their respective mRNAs suggests that IGFBPs are important paracrine factors in the regulation of IGF action in the developing lung.


2010 ◽  
Vol 298 (6) ◽  
pp. L775-L783 ◽  
Author(s):  
Yulian Wang ◽  
Benjamin S. Maciejewski ◽  
Diana Drouillard ◽  
Melissa Santos ◽  
Michael A. Hokenson ◽  
...  

Mechanical forces are critical for fetal lung development. Using surfactant protein C (SP-C) as a marker, we previously showed that stretch-induced fetal type II cell differentiation is mediated via the ERK pathway. Caveolin-1, a major component of the plasma membrane microdomains, is important as a signaling protein in blood vessels exposed to shear stress. Its potential role in mechanotransduction during fetal lung development is unknown. Caveolin-1 is a marker of type I epithelial cell phenotype. In this study, using immunocytochemistry, Western blotting, and immunogold electron microscopy, we first demonstrated the presence of caveolin-1 in embryonic day 19 (E19) rat fetal type II epithelial cells. By detergent-free purification of lipid raft-rich membrane fractions and fluorescence immunocytochemistry, we found that mechanical stretch translocates caveolin-1 from the plasma membrane to the cytoplasm. Disruption of the lipid rafts with cholesterol-chelating agents further increased stretch-induced ERK activation and SP-C gene expression compared with stretch samples without disruptors. Similar results were obtained when caveolin-1 gene was knocked down by small interference RNA. In contrast, adenovirus overexpression of the wild-type caveolin-1 or delivery of caveolin-1 scaffolding domain peptide inside the cells decreased stretch-induced ERK phosphorylation and SP-C mRNA expression. In conclusion, our data suggest that caveolin-1 is present in E19 fetal type II epithelial cells. Caveolin-1 is translocated from the plasma membrane to the cytoplasm by mechanical stretch and functions as an inhibitory protein in stretch-induced type II cell differentiation via the ERK pathway.


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