Respiratory epithelium

About: Respiratory epithelium is a research topic. Over the lifetime, 5048 publications have been published within this topic receiving 222304 citations. The topic is also known as: respiratory tract epithelium & Respiratory Mucosa.

Peroxisome proliferator–activated receptor γ is expressed in airways and inhibits features of airway remodeling in a mouse asthma model

Abstract: Background Allergic asthma is associated with persistent functional and structural changes in the airways and involves many different cell types. Peroxisome proliferator–activated receptor γ (PPAR-γ), a member of the nuclear hormone receptor superfamilly, is predominantly expressed in adipose tissue and plays a major role in regulating adipocyte differentiation and glucose metabolism. Recently, PPAR-γ has been shown to play an important role in the control of inflammatory responses, including within the lung, acting on both immune and nonimmune cells. Objective Our aim was to assess the anti-inflammatory potential of a PPAR-γ agonist locally delivered by means of nebulization. Methods We used a mouse model of asthma induced by sensitization and airway challenge with ovalbumin. Ciglitazone, a PPAR-γ agonist, was administered by means of nebulization alone at the time of antigen challenge or by means of gavage and nebulization. Treatments with both ciglitazone and GW9662, a specific antagonist, were also performed to verify that ciglitazone's effects were mediated through PPAR-γ activation. Results Our results show that PPAR-γ is mainly expressed in airway epithelium on antigen sensitization. Treatment with ciglitazone reduced PPAR-γ levels in the lung, whereas combined treatment with GW9662 abrogated this inhibition. Importantly, nebulization with ciglitazone decreased airway hyperresponsiveness, basement membrane thickness, mucus production, collagen deposition, and TGF-β synthesis. A significant correlation was also found between airway hyperresponsiveness, basement membrane thickness, and TGF-β levels. Conclusion These results demonstrate that inhaled agonistic ligands of PPAR-γ might have new therapeutic potential for airway asthmatic inflammation.

Decreased Cu,Zn-SOD activity in asthmatic airway epithelium: correction by inhaled corticosteroid in vivo

Abstract: To investigate the antioxidant response of respiratory epithelium to the chronic airway inflammation in asthma, the major intracellular antioxidants [copper and zinc-containing superoxide dismutase (Cu,Zn-SOD) and manganese-containing SOD (Mn-SOD), catalase, and glutathione peroxidase] were quantitated in bronchial epithelial cells of healthy control and asthmatic individuals. Although catalase and glutathione peroxidase in bronchial epithelium of asthmatics were similar to control SOD activity in asthmatics not on inhaled corticosteroid (-CS) was lower than asthmatics on inhaled corticosteroid (+CS) and controls. Investigation of Mn-SOD and Cu,Zn-SOD activities revealed that the lower SOD activity in asthmatics -CS was because of decreased Cu,Zn-SOD activity. However, Mn-SOD and Cu,Zn-SOD mRNA and protein levels were similar among asthmatics -CS, asthmatics +CS, and controls. Importantly, Cu,Zn-SOD specific activity in asthmatics -CS was decreased in comparison with control and asthmatics +CS. Furthermore, in paired comparisons of asthmatics -CS and +CS, inhaled corticosteroids resulted in normalization of bronchial epithelial Cu,Zn-SOD specific activity. These findings suggest loss of Cu,Zn-SOD activity in asthma is related to inflammation, perhaps through oxidant inactivation of Cu,Zn-SOD protein.

Derivation of distal airway epithelium from human embryonic stem cells.

Abstract: The pluripotency of embryonic stem cells (ESC) is offering new opportunities in tissue engineering and cell therapy. We have shown previously that alveolar epithelial cells, specifically type II pneumocytes, can be derived from murine ESC and hypothesized that a similar protocol could be used successfully on human ESC. Undifferentiated human ESC were induced to form embryoid bodies that were transferred into adherent culture conditions and grown in a medium designed for the maintenance of mature small airway epithelium. On inverted microscopy, the generated cells showed the cobblestone-like morphology of epithelium. The presence of surfactant protein C, a specific marker of type II pneumocytes, and its corresponding RNA were demonstrated by immunostaining and reverse transcription polymerase chain reaction, respectively. Electron microscopy revealed frequent cells with the typical ultrastructure of type II pneumocytes. This study provides evidence for in vitro induction of the differentiation from human ESC of alveolar type II cells, which have the potential for therapeutic use or construction of an in vitro model of human lung.

A contiguous network of dendritic antigen-presenting cells within the respiratory epithelium.

Abstract: This study utilises a simple technique to section airway epithelium in a plane parallel to the basement membrane, thus providing a unique plan view of the intra-epithelial cell populations. Immunopero