Phenotypic Analysis of BrdU Label-Retaining Cells during the Maturation of Conducting Airway Epithelium in a Porcine Lung

Stem/progenitor cells have recently been demonstrated to play key roles in the maturation, injury repair, and regeneration of distinct organs or tissues. Porcine has spurred an increased interest in biomedical research models and xenotransplantation, owing to most of its organs share similarities in physiology, cellular composition and size to humans. Therefore, characterization of stem/progenitor cells in porcine organs or tissues may provide a novel avenue to better understand the biology and function of stem cells in humans. In the present study, potential stem/progenitor cells in conducting airway epithelium of a porcine lung were characterized by morphometric analysis of bromodeoxyuridine (BrdU) label-retaining cells (LRCs) during the maturation of the lung. The results showed a pseudostratified mucociliary epithelium comprised of basal, ciliated, goblet, and columnar cells in the conducting airway of a porcine lung. In addition, the majority of primary epithelial cells able to proliferate in vitro expressed keratin 5, a subpopulation of these keratin 5-positive cells, also expressed CD117 (c-Kit) or CD49f (integrin alpha 6, ITGA6), implying that they might be potential epithelial stem/progenitor cells in conducting airway of a porcine lung. Lineage tracing analysis with a BrdU-labeled neonatal piglet showed that the proportion of BrdU-labeled cells in conducting airways decreased over the 90-day period of lung maturation. The BrdU-labeled epithelial cells also expressed keratin 14, mucin 5AC, or prosurfactant protein C (ProSP-C); among them, the keratin 14-positive cells were the most frequent BrdU-labeled epithelial cell type as determined by immunohistochemical and immunofluorescence staining. This study may provide valuable information on the biology and function of epithelial stem/progenitor cells in conducting airway of pigs and humans.

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Neonatal Wnt-dependent Lgr5 positive stem cells are essential for uterine gland development

Nature Communications ◽

10.1038/s41467-019-13363-3 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 5

Author(s):

Ryo Seishima ◽

Carly Leung ◽

Swathi Yada ◽

Katzrin Bte Ahmed Murad ◽

Liang Thing Tan ◽

...

Keyword(s):

Stem Cells ◽

Progenitor Cells ◽

Reproductive Tract ◽

Ex Vivo ◽

Lineage Tracing ◽

Major Advance ◽

Uterine Gland ◽

And Function ◽

Gland Development

AbstractWnt signaling is critical for directing epithelial gland development within the uterine lining to ensure successful gestation in adults. Wnt-dependent, Lgr5-expressing stem/progenitor cells are essential for the development of glandular epithelia in the intestine and stomach, but their existence in the developing reproductive tract has not been investigated. Here, we employ Lgr5-2A-EGFP/CreERT2/DTR mouse models to identify Lgr5-expressing cells in the developing uterus and to evaluate their stem cell identity and function. Lgr5 is broadly expressed in the uterine epithelium during embryogenesis, but becomes largely restricted to the tips of developing glands after birth. In-vivo lineage tracing/ablation/organoid culture assays identify these gland-resident Lgr5high cells as Wnt-dependent stem cells responsible for uterine gland development. Adjacent Lgr5neg epithelial cells within the neonatal glands function as essential niche components to support the function of Lgr5high stem cells ex-vivo. These findings constitute a major advance in our understanding of uterine development and lay the foundations for investigating potential contributions of Lgr5+ stem/progenitor cells to uterine disorders.

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Fibroblast growth factor-9 expression in airway epithelial cells amplifies the type I interferon response and alters influenza A virus pathogenesis

10.1101/2021.12.22.473953 ◽

2021 ◽

Author(s):

Bradley Hiller ◽

Yongjun Yin ◽

Yi-Chieh Perng ◽

Ítalo de Araujo Castro ◽

Lindsey Fox ◽

...

Keyword(s):

Epithelial Cells ◽

Virus Infection ◽

Airway Epithelium ◽

Influenza A ◽

Alveolar Epithelium ◽

Airway Epithelial Cells ◽

Type I ◽

Airway Epithelial ◽

Conducting Airway ◽

Respiratory Virus Infection

Influenza A virus (IAV) preferentially infects conducting airway and alveolar epithelial cells in the lung. The outcome of these infections is impacted by the host response, including the production of various cytokines, chemokines, and growth factors. Fibroblast growth factor-9 (FGF9) is required for lung development, can display antiviral activity in vitro, and is upregulated in asymptomatic patients during early IAV infection. We therefore hypothesized that FGF9 would protect the lungs from respiratory virus infection and evaluated IAV pathogenesis in mice that overexpress FGF9 in club cells in the conducting airway epithelium (FGF9-OE mice). However, we found that FGF9-OE mice were highly susceptible to IAV and Sendai virus infection compared to control mice. FGF9-OE mice displayed elevated and persistent viral loads, increased expression of cytokines and chemokines, and increased numbers of infiltrating immune cells as early as 1 day post-infection (dpi). Gene expression analysis showed an elevated type I interferon (IFN) signature in the conducting airway epithelium and analysis of IAV tropism uncovered a dramatic shift in infection from the conducting airway epithelium to the alveolar epithelium in FGF9-OE lungs. These results demonstrate that FGF9 signaling primes the conducting airway epithelium to rapidly induce a localized, protective IFN and proinflammatory cytokine response during viral infection. Although this response protects the airway epithelial cells from IAV infection, it allows for early and enhanced infection of the alveolar epithelium, ultimately leading to increased morbidity and mortality. Our study illuminates a novel role for FGF9 in regulating respiratory virus infection and pathogenesis.

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

10.1101/2020.06.04.134338 ◽

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.

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In vivo replacement of damaged bladder urothelium by Wolffian duct epithelial cells

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1802966115 ◽

2018 ◽

Vol 115 (33) ◽

pp. 8394-8399 ◽

Cited By ~ 5

Author(s):

Diya B. Joseph ◽

Anoop S. Chandrashekar ◽

Lisa L. Abler ◽

Li-Fang Chu ◽

James A. Thomson ◽

...

Keyword(s):

Epithelial Cells ◽

Dna Methyltransferase ◽

Wolffian Duct ◽

Bladder Epithelium ◽

Bladder Urothelium ◽

Keratin 5 ◽

Bladder Regeneration ◽

Bladder Cells ◽

And Function

The bladder’s remarkable regenerative capacity had been thought to derive exclusively from its own progenitors. While examining consequences of DNA methyltransferase 1 (Dnmt1) inactivation in mouse embryonic bladder epithelium, we made the surprising discovery that Wolffian duct epithelial cells can support bladder regeneration. Conditional Dnmt1 inactivation in mouse urethral and bladder epithelium triggers widespread apoptosis, depletes basal and intermediate bladder cells, and disrupts uroplakin protein expression. These events coincide with Wolffian duct epithelial cell recruitment into Dnmt1 mutant urethra and bladder where they are reprogrammed to express bladder markers, including FOXA1, keratin 5, P63, and uroplakin. This is evidence that Wolffian duct epithelial cells are summoned in vivo to replace damaged bladder epithelium and function as a reservoir of cells for bladder regeneration.

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

eLife ◽

10.7554/elife.57325 ◽

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.

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Lrig1 expression identifies airway basal cells with high proliferative capacity and restricts lung squamous cell carcinoma growth

European Respiratory Journal ◽

10.1183/13993003.00816-2020 ◽

2021 ◽

pp. 2000816

Author(s):

Laura Succony ◽

Sandra Gómez-López ◽

Adam Pennycuick ◽

Ahmed S. N. Alhendi ◽

Derek Davies ◽

...

Keyword(s):

Lung Cancer ◽

Squamous Cell Carcinoma ◽

Epithelial Cells ◽

Cell Carcinoma ◽

Progenitor Cells ◽

Squamous Cell ◽

Airway Epithelium ◽

Lung Squamous Cell Carcinoma ◽

Airway Epithelial Cells ◽

Airway Epithelial

Lung squamous cell carcinoma (LUSC) accounts for a significant proportion of cancer deaths worldwide, and is preceded by the appearance of progressively disorganised pre-invasive lesions in the airway epithelium. Yet the biological mechanisms underlying progression of pre-invasive lesions into invasive LUSC are not fully understood. LRIG1 is downregulated in pre-invasive airway lesions and invasive LUSC tumours and this correlates with decreased lung cancer patient survival.Using an Lrig1 knock-in reporter mouse and human airway epithelial cells collected at bronchoscopy, we show that during homeostasis LRIG1 is heterogeneously expressed in the airway epithelium. In basal airway epithelial cells, the suspected cell of origin of LUSC, LRIG1 identifies a subpopulation of progenitor cells with higher in vitro proliferative and self-renewal potential in both the mouse and human. Using the N-nitroso-tris-chloroethylurea (NTCU)-induced murine model of LUSC, we find that Lrig1 loss-of-function leads to abnormally high cell proliferation during the earliest stages of pre-invasive disease and to the formation of significantly larger invasive tumours, suggesting accelerated disease progression.Together, our findings identify LRIG1 as a marker of basal airway progenitor cells with high proliferative potential and as a regulator of pre-invasive lung cancer progression. This work highlights the clinical relevance of LRIG1 and the potential of the NTCU-induced LUSC model for functional assessment of candidate tumour suppressors and oncogenes.

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New Ultrastructural Observations on Injury and Regeneration of Cilia in Mammalian Conducting Airway Epithelium

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100099544 ◽

1981 ◽

Vol 39 ◽

pp. 624-625

Author(s):

J.L. Carson ◽

A.M. Collier

Keyword(s):

Respiratory Tract ◽

Airway Epithelium ◽

Defense Mechanisms ◽

Normal Growth ◽

Fetal Lung ◽

Secretory Cells ◽

Airway Epithelial ◽

Ciliated Cells ◽

Conducting Airway ◽

Conducting Airways

The ciliated cells lining the conducting airways of mammals are integral to the defense mechanisms of the respiratory tract, functioning in coordination with secretory cells in the removal of inhaled and cellular debris. The effects of various infectious and toxic agents on the structure and function of airway epithelial cell cilia have been studied in our laboratory, both of which have been shown to affect ciliary ultrastructure.These observations have led to questions about ciliary regeneration as well as the possible induction of ciliogenesis in response to cellular injury. Classical models of ciliogenesis in the conducting airway epithelium of the mammalian respiratory tract have been based primarily on observations of the developing fetal lung. These observations provide a plausible explanation for the embryological generation of ciliary beds lining the conducting airways but do little to account for subsequent differentiation of ciliated cells and ciliogenesis during normal growth and development.

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