Search results for "Respiratory epithelium"
showing 10 items of 37 documents
Vitamin A and ciliated cells I. Respiratory epithelia
1986
To estimate the role of vitamin A on ciliated cells we investigated whether ciliated cells undergo any alteration during vitamin A deficiency. The epithelia examined include the ciliated cells of the respiratory tract and the ciliated sensory cells of the inner ear, the tongue, and the olfactory cells. This part of the paper will describe the ciliated epithelium of the tracheobronchial tract and its relation to vitamin A status. During vitamin A deficiency a partial loss of ciliae can be observed before any squamous metaplasia (which usually occurs during longer lasting vitamin A deficiency) develops. The scanning electron microscopic data illustrate the altered surface of the epithelium du…
Caged Dexamethasone/Quercetin Nanoparticles, Formed of the Morphogenetic Active Inorganic Polyphosphate, are Strong Inducers of MUC5AC
2021
Inorganic polyphosphate (polyP) is a widely distributed polymer found from bacteria to animals, including marine species. This polymer exhibits morphogenetic as well as antiviral activity and releases metabolic energy after enzymatic hydrolysis also in human cells. In the pathogenesis of the coronavirus disease 2019 (COVID-19), the platelets are at the frontline of this syndrome. Platelets release a set of molecules, among them polyP. In addition, the production of airway mucus, the first line of body defense, is impaired in those patients. Therefore, in this study, amorphous nanoparticles of the magnesium salt of polyP (Mg-polyP-NP), matching the size of the coronavirus SARS-CoV-2, were pr…
Extracellular calcium-sensing receptor mediates human bronchial epithelial wound repair
2010
The airway epithelium routinely undergoes damage that requires repair to restore epithelial barrier integrity. Cell migration followed by proliferation are necessary steps to achieve epithelial repair. Calcium-sensing receptor (CaSR) is implicated in cell migration and proliferation processes. Thus we hypothesized that CaSR mediates lung epithelial wound repair. We detected CaSR expression in human lung and in well-differentiated human bronchial epithelial cells (HBEC). To test the CaSR functionality, HBEC loaded with fura-2 were stimulated with extracellular Ca(2+) ([Ca(2+)](out)) which resulted in a concentration-dependent intracellular Ca(2+) ([Ca(2+)](i)) increase (potency approximately…
Role of chronic exposure to cigarette smoke on endoglin/CD105 expression in airway epithelium
2015
Dysregulation of airway epithelium function related to cigarette smoke exposure plays an important role in the pathophysiology of COPD and is associated to tissue damage and disease severity. CD105 is a component of the receptor complex of TGF-β, a pleiotropic cytokine involved in cellular proliferation, differentiation and migration. CD105 regulates the expression of different components of the extracellular matrix suggesting a role of CD105 in cellular transmigration and remodeling processes. The aim of the present study was to investigate the expression of endoglin/CD105 in airway epithelium of COPD patients and its involvement in tissue remodeling and COPD progression. We evaluated the …
Barrier functions and paracellular integrity in human cell culture models of the proximal respiratory unit.
2009
International audience; Airway epithelial cells provide a barrier to the translocation of inhaled materials. Tight (TJ) and adherens junctions (AJ) play a key role in maintaining barrier functions, and are responsible for the selective transport of various substances through the paracellular pathway. In this study we compared a bronchial cell line (16HBE14o-) and primary bronchial cells (HBEC), both cocultivated with the fibroblast cell line Wi-38, with respect to their structural differentiation and their reaction to cytokine stimulation. HBEC formed a pseudostratified epithelial layer and expressed TJ and AJ proteins after 2 weeks in coculture. Mucus-producing and ciliated cells were foun…
Effects of normobaric oxygen on ciliary beat frequency of human respiratory epithelium
1998
Respiratory infection is a major cause of morbidity after general anaesthesia. Impairment of respiratory ciliary beat frequency (CBF) by different stress factors causes a decrease in mucus transport rate (MTR). We have tested the effect of different concentrations of oxygen on CBF of human respiratory epithelium in a prospective, randomized, in vitro study. Samples of superficial mucosa of the inferior nasal turbinates of 20 non-smoking healthy volunteers were harvested and exposed to three different oxygen environments (group I = 21% oxygen, group II = 60% oxygen and group III = 95% oxygen) for 2 h. In 50% of the samples, exposure time was prolonged. At 30, 60, 90, 120 and 240 min, light m…
Airway epithelium: more than just a barrier!
1999
Abstract Airway epithelium: source of non-neuronal acetylcholine and modulator of neurotransmission
Epithelial-mesenchymal communication in the pathogenesis of chronic asthma.
2005
Although Th-2-mediated inflammation is a key therapeutic target in asthma, its relationship to altered structure and functions of the airways is largely unknown. In addition to inflammation, asthma is a disorder involving the airway epithelium that is more vulnerable to environmental injury and responds to this by impaired healing. This establishes a chronic wound scenario that is capable of sustaining chronic inflammation as well as remodeling. This response occurs as a consequence of activation of the epithelial-mesenchymal unit, involving reciprocal activities of growth factors belonging to the fibroblast growth factor, epidermal growth factor, and transforming growth factor-beta familie…
Effects of bacterial lipopolysaccharides (LPS) and tumour necrosis factor-alpha (TNF alpha) on rat tracheal epithelial cells in culture: morphology, …
1996
Rat tracheal epithelial cells were cultured and the effects of LPS and TNF alpha on cell morphology, rate of proliferation and NO synthase activity were studied. NO synthase activity was determined by measuring the accumulation of 3H-L-citrulline during incubation of confluent monolayer with 3H-L-arginine. In untreated cells no significant 3H-L-citrulline formation was detected, and bradykinin and the calcium ionophore A 23187 failed to stimulate 3H-L-citrulline formation excluding a constitutively expressed, calcium-dependent NO synthase activity. After culturing the cells for 18 h in the presence of LPS (10 micrograms/ml) and TNF alpha (500 U/ml) a marked formation of 3H-L-citrulline coul…
Authors' response to: epithelial mesenchymal transition (EMT) in small airways of COPD patient.
2013
We understand the reservations highlighted by Sohal and Walters in their letter in response to our recent work published.1 In their letter, Sohal and Walters argue that E-cadherin and ZO-1 are absent in our immunohistochemistry analysis of small bronchi of smokers and COPD patients, and that if disappeared completely epithelium would fall apart.1 In our study, we detected downregulation of E-cadherin and ZO-1 as well as a change of intercellular and apical distribution to diffuse cytoplasmic redistribution (figure 3B; in our work published in Thorax on 7 January 2013),2 but not …