scholarly journals Prom1 and Notch regulate ciliary length and dynamics in multiciliated cells of the airway epithelium

2022 ◽  
Author(s):  
Carlos F Hurtado Serra ◽  
Helu Liu ◽  
Jun Qian ◽  
Munemasa Mori ◽  
Jining Lu ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Airway Epithelium ◽  
Transmembrane Protein ◽  
Cell Phenotype ◽  
Phenotypic Differences ◽  
Innate Defense ◽  
Multiciliated Cells ◽  
Environmental Agents ◽  
Mammalian Lung

Differences in ciliary morphology and dynamics among multiciliated cells of the respiratory tract have been well reported and known to contribute to efficient mucociliary clearance. Nevertheless, little is known about how phenotypic differences among multiciliated cells are established in the mammalian lung. Here we show that Prominin-1 (Prom1), a transmembrane protein widely used as stem cell and tumor-initiating marker, is crucial to this process. During airway differentiation, Prom1 becomes restricted to multiciliated cells, where it is expressed at distinct levels along the proximal-distal axis of the airways and in the adult airway epithelium in vitro. We found that Prom1 is induced by Notch in post-specified multiciliated cells and that Notch inactivation abolishes the gradients of Prom1 in the developing airways and in differentiating organotypic cultures. Prom1 was not required for multicilia formation and when inactivated resulted in longer cilia, which remained functional but beating at a lower frequency. Disruption of Notch resulted in opposite effects and suggested that Notch fine-tunes Prom1 levels to regulate the multiciliated cell phenotype and generate diversity among these cells in the respiratory tract. By controlling these features, this mechanism contributes to the innate defense of the lung against environmental agents and prevent pulmonary disease.

scholarly journals Junctional Adhesion Molecule 3 Expression in the Mouse Airway Epithelium Is Linked to Multiciliated Cells

2021 ◽  
Vol 9 ◽  
Author(s):  
Clara Maria Mateos-Quiros ◽  
Sergio Garrido-Jimenez ◽  
Guadalupe Álvarez-Hernán ◽  
Selene Diaz-Chamorro ◽  
Juan Francisco Barrera-Lopez ◽  
...  
Keyword(s):  
Stem Cell ◽  
Adhesion Molecule ◽  
Airway Epithelium ◽  
Barrier Function ◽  
Cell Types ◽  
Specific Cell ◽  
Recycling Endosome ◽  
Multiciliated Cells ◽  
Beating Frequency

Tight-junction (TJ) proteins are essential for establishing the barrier function between neighbor epithelial cells, but also for recognition of pathogens or cell migration. Establishing the expression pattern and localization of different TJ proteins will help to understand the development and physiology of the airway. Here we identify that the junctional adhesion molecule 3 (Jam3) expression is restricted to multiciliated cells (MCCs) in the airway epithelium. In vitro, Jam3 expression varies along airway basal stem cell (BSC) differentiation and upon DAPT treatment or IL6 exposure. However, Jam3 is not required for BSC differentiation to specific cell types. In addition, we found that MCC lacking Jam3 display normal cilia morphology and cilia beating frequency with a delay in BB assembly/positioning in MCCs during differentiation. Remarkably, Jam3 in MCC is mostly localized to subapical organelles, which are negative for the apical recycling endosome marker Rab11 and positive for EEA1. Our data show that Jam3 expression is connected to mature MCC in the airway epithelium and suggest a Jam3 role unrelated to its known barrier function.

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

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.

Preliminary Report of In vitro and In vivo Effectiveness of Dornase Alfa on SARS-CoV-2 Infection (Preprint)

2020 ◽  
Author(s):  
Hacer Kuzu Okur ◽  
Koray Yalcin ◽  
Cihan Tastan ◽  
Sevda Demir ◽  
Bulut Yurtsever ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Respiratory Tract ◽  
Mononuclear Cells ◽  
Multiple Organ ◽  
Peripheral Blood Mononuclear ◽  
Dornase Alfa ◽  
Tract Infections ◽  
Adult Peripheral Blood

UNSTRUCTURED Dornase alfa, the recombinant form of the human DNase I enzyme, breaks down neutrophil extracellular traps (NET) that include a vast amount of DNA fragments, histones, microbicidal proteins and oxidant enzymes released from necrotic neutrophils in the highly viscous mucus of cystic fibrosis patients. Dornase alfa has been used for decades in patients with cystic fibrosis to reduce the viscoelasticity of respiratory tract secretions, to decrease the severity of respiratory tract infections, and to improve lung function. Previous studies have linked abnormal NET formations to lung diseases, especially to acute respiratory distress syndrome (ARDS). Coronavirus disease 2019 (COVID-19) pandemic affected more than two million people over the world, resulting in unprecedented health, social and economic crises. The COVID-19, viral pneumonia that progresses to ARDS and even multiple organ failure, is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). High blood neutrophil levels are an early indicator of SARS-CoV-2 infection and predict severe respiratory diseases. A similar mucus structure is detected in COVID-19 patients due to the accumulation of excessive NET in the lungs. Here, we show our preliminary results with dornase alfa that may have an in-vitro anti-viral effect against SARS-CoV-2 infection in a bovine kidney cell line, MDBK without drug toxicity on healthy adult peripheral blood mononuclear cells. In this preliminary study, we also showed that dornase alfa can promote clearance of NET formation in both an in-vitro and three COVID-19 cases who showed clinical improvement in radiological analysis (2-of-3 cases), oxygen saturation (SpO2), respiratory rate, disappearing of dyspnea and coughing.

scholarly journals Elevated expression of the adhesion GPCR ADGRL4/ELTD1 promotes endothelial sprouting angiogenesis without activating canonical GPCR signalling

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David M. Favara ◽  
Ines Liebscher ◽  
Ali Jazayeri ◽  
Madhulika Nambiar ◽  
Helen Sheldon ◽  
...  
Keyword(s):  
Transcriptional Profiling ◽  
Gc Content ◽  
Luciferase Reporter ◽  
Cell Phenotype ◽  
Beta Catenin ◽  
Sprouting Angiogenesis ◽  
Proteolytic Site ◽  
Elevated Expression ◽  
Adhesion Gpcr

AbstractADGRL4/ELTD1 is an orphan adhesion GPCR (aGPCR) expressed in endothelial cells that regulates tumour angiogenesis. The majority of aGPCRs are orphan receptors. The Stachel Hypothesis proposes a mechanism for aGPCR activation, in which aGPCRs contain a tethered agonist (termed Stachel) C-terminal to the GPCR-proteolytic site (GPS) cleavage point which, when exposed, initiates canonical GPCR signalling. This has been shown in a growing number of aGPCRs. We tested this hypothesis on ADGRL4/ELTD1 by designing full length (FL) and C-terminal fragment (CTF) ADGRL4/ELTD1 constructs, and a range of potential Stachel peptides. Constructs were transfected into HEK293T cells and HTRF FRET, luciferase-reporter and Alphascreen GPCR signalling assays were performed. A stable ADGRL4/ELTD1 overexpressing HUVEC line was additionally generated and angiogenesis assays, signalling assays and transcriptional profiling were performed. ADGRL4/ELTD1 has the lowest GC content in the aGPCR family and codon optimisation significantly increased its expression. FL and CTF ADGRL4/ELTD1 constructs, as well as Stachel peptides, did not activate canonical GPCR signalling. Furthermore, stable overexpression of ADGRL4/ELTD1 in HUVECs induced sprouting angiogenesis, lowered in vitro anastomoses, and decreased proliferation, without activating canonical GPCR signalling or MAPK/ERK, PI3K/AKT, JNK, JAK/HIF-1α, beta catenin or STAT3 pathways. Overexpression upregulated ANTXR1, SLC39A6, HBB, CHRNA, ELMOD1, JAG1 and downregulated DLL4, KIT, CCL15, CYP26B1. ADGRL4/ELTD1 specifically regulates the endothelial tip-cell phenotype through yet undefined signalling pathways.

Elucidating the anti-biofilm and anti-quorum sensing potential of selenocystine against respiratory tract infections causing bacteria: in vitro and in silico studies

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bharti Patel ◽  
Subrata Mishra ◽  
Indira K. Priyadarsini ◽  
Sirisha L. Vavilala
Keyword(s):  
Quorum Sensing ◽  
Respiratory Tract ◽  
Protein Function ◽  
Docking Studies ◽  
Klebsiella Pneumonia ◽  
Potential Candidate ◽  
In Silico Studies ◽  
Specific Proteins ◽  
Tract Infections

Abstract Bacteria are increasingly relying on biofilms to develop resistance to antibiotics thereby resulting in their failure in treating many infections. In spite of continuous research on many synthetic and natural compounds, ideal anti-biofilm molecule is still not found thereby warranting search for new class of molecules. The current study focuses on exploring anti-biofilm potential of selenocystine against respiratory tract infection (RTI)-causing bacteria. Anti-bacterial and anti-biofilm assays demonstrated that selenocystine inhibits the growth of bacteria in their planktonic state, and formation of biofilms while eradicating preformed-biofilm effectively. Selenocystine at a MIC50 as low as 42 and 28 μg/mL effectively inhibited the growth of Klebsiella pneumonia and Pseudomonas aeruginosa. The antibacterial effect is further reconfirmed by agar cup diffusion assay and growth-kill assay. Selenocystine showed 30–60% inhibition of biofilm formation in K. pneumonia, and 44–70% in P. aeruginosa respectively. It also distorted the preformed-biofilms by degrading the eDNA component of the Extracellular Polymeric Substance matrix. Molecular docking studies of selenocystine with quorum sensing specific proteins clearly showed that through the carboxylic acid moiety it interacts and inhibits the protein function, thereby confirming its anti-biofilm potential. With further validation selenocystine can be explored as a potential candidate for the treatment of RTIs.

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