Expression of ISG60 is induced by TLR3 signaling in BEAS­2B bronchial epithelial cells: Possible involvement in CXCL10 expression.

Viral infections in the respiratory tract are common, and, in recent years, severe acute respiratory syndrome coronavirus 2 outbreaks have highlighted the effect of viral infections on antiviral innate immune and inflammatory reactions. Specific treatments for numerous viral respiratory infections have not yet been established and they are mainly treated symptomatically. Therefore, understanding the details of the innate immune system underlying the airway epithelium is crucial for the development of new therapies. The present study aimed to investigate the function and expression of interferon (IFN)­stimulated gene (ISG)60 in non­cancerous bronchial epithelial BEAS­2B cells exposed to a Toll­like receptor 3 agonist. BEAS­2B cells were treated with a synthetic TLR3 ligand, polyinosinic­polycytidylic acid (poly IC). The mRNA and protein expression levels of ISG60 were analyzed using reverse transcription­quantitative PCR and western blotting, respectively. The levels of C­X­C motif chemokine ligand 10 (CXCL10) were examined using an enzyme­linked immunosorbent assay, and the effects of knockdown of IFN­ß, ISG60 and ISG56 were examined using specific small interfering RNAs. Notably, ISG60 expression was increased in proportion to poly IC concentration, and recombinant human IFN­ß also induced ISG60 expression. By contrast, knockdown of IFN­ß and ISG56 decreased ISG60 expression, and ISG60 knockdown reduced CXCL10 and ISG56 expression. These findings suggested that ISG60 is partly implicated in CXCL10 expression and that ISG60 may serve a role in the innate immune response of bronchial epithelial cells. The present study highlights ISG60 as a potential target for new therapeutic strategies against viral infections in the airway.

Common double-lumen tube selection methods overestimate adequate tube sizes in individual patients - a 3D reconstruction study.

BACKGROUND: Appropriate selection of double-lumen tube sizes for one-lung ventilation is crucial to prevent airway damage. Current selection methods rely on demographic factors or 2D radiography. Prediction of left bronchial diameter is indispensable for choosing the adequate tube size. This prospective observational study investigates if current selection methods sufficiently predict individuals' left bronchial diameters for DLT selection compared to the 3D reconstruction. METHODS: 100 patients necessitating thoracic surgery with one-lung ventilation and left-sided double-lumen tubes, ≥ 18 years of age, and a set of chest X-rays and 2D thorax CT scans for 3D reconstruction of the left main bronchus were included between 07/2021 and 06/2023. The cross-validated prediction error and the width of the 95%-prediction intervals of the 3D left main bronchial diameter utilizing linear prediction models were based on current selection methods. RESULTS: The mean bronchial diameter in 3D reconstruction was 13.6 ± 2.1 mm. The ranges of the 95%-prediction intervals for the bronchial diameter were 6.4 mm for demographic variables, 8.3 mm for the tracheal diameter from the X-ray, and 5.9 mm for bronchial diameter from the 2D-CT scans. Current methods violated the suggested '≥1 mm' safety criterion in up to 7% (men) and 42% (women). Particularly, 2D radiography overestimated women's left bronchial diameter. Current methods even allowed the selection of double-lumen tubes with bronchial tube sections greater than the bronchial diameter in women. CONCLUSIONS: Neither demographic nor 2D-radiographic methods sufficiently account for the variability of the bronchial diameter. Wide 95%-prediction intervals for the bronchial diameter hamper accurate individual double-lumen tube selection. This increases women's risk of bronchial damage, particularly if they have other predisposing factors. These patients may benefit from 3D reconstruction of the left main bronchus. TRIAL REGISTRATION: Not applicable.

Complete transection of the bilateral main bronchus in a 5-year-old patient: a case report.

BACKGROUND: Tracheobronchial injuries caused by blunt chest trauma are rare in children, and such injuries usually involve multiple organs. Most cases involve respiratory failure on the way to the hospital, and the mortality rate is high. Herein, we describe the case of a 5-year-old patient who fell from an electric vehicle, causing complete rupture of the bilateral main bronchus. CASE PRESENTATION: We treated a 5-year-old patient with complete bilateral main bronchus rupture. Chest computed tomography (CT) failed to detect bronchial rupture. Continuous closed thoracic drainage resulted in a large amount of bubble overflow. Tracheal rupture was suspected. Fibreoptic bronchoscopy revealed complete rupture of the right main bronchus and rupture of the left main bronchus. Emergency tracheoplasty was performed under cardiopulmonary bypass (CPB). During the operation, we found that the bilateral main bronchi were completely ruptured. Postoperative recovery was smooth. The traditional surgical method for treating these injuries is lateral thoracotomy. However, a median sternotomy provides a better opportunity for selective repair. Extracorporeal circulation-assisted surgery is required for patients with unstable breathing. CONCLUSION: Complete fractures of the bilateral main bronchi are rare. Bronchial rupture should be suspected in the presence of expansion defect-dropped lungs and massive air leakage despite tube thoracostomy in haemopneumothorax developing after thoracic trauma. Extracorporeal circulation-assisted tracheoplasty is a relatively safe option for children whose respiratory system is difficult to maintain, thus ensuring oxygenation ventilation and a clear surgical field.

Low-Dose CT-derived Bronchial Parameters in Individuals with Healthy Lungs.

Background CT-derived bronchial parameters have been linked to chronic obstructive pulmonary disease and asthma severity, but little is known about these parameters in healthy individuals. Purpose To investigate the distribution of bronchial parameters at low-dose CT in individuals with healthy lungs from a Dutch general population. Materials and Methods In this prospective study, low-dose chest CT performed between May 2017 and October 2022 were obtained from participants who had completed the second-round assessment of the prospective, longitudinal Imaging in Lifelines study. Participants were aged at least 45 years, and those with abnormal spirometry, self-reported respiratory disease, or signs of lung disease at CT were excluded. Airway lumens and walls were segmented automatically. The square root of the bronchial wall area of a hypothetical airway with an internal perimeter of 10 mm (Pi10), luminal area (LA), wall thickness (WT), and wall area percentage were calculated. Associations between sex, age, height, weight, smoking status, and bronchial parameters were assessed using univariable and multivariable analyses. Results The study sample was composed of 8869 participants with healthy lungs (mean age, 60.9 years ± 10.4 [SD]; 4841 [54.6%] female participants), including 3672 (41.4%) never-smokers and 1197 (13.5%) individuals who currently smoke. Bronchial parameters for male participants were higher than those for female participants (Pi10, slope [ß] range = 3.49-3.66 mm; LA, ß range = 25.40-29.76 mm2; WT, ß range = 0.98-1.03 mm; all P < .001). Increasing age correlated with higher Pi10, LA, and WT (r2 range = 0.06-0.09, 0.02-0.01, and 0.02-0.07, respectively; all P < .001). Never-smoking individuals had the lowest Pi10 followed by formerly smoking and currently smoking individuals (3.62 mm ± 0.13, 3.68 mm ± 0.14, and 3.70 mm ± 0.14, respectively; all P < .001). In multivariable regression models, age, sex, height, weight, and smoking history explained up to 46% of the variation in bronchial parameters. Conclusion In healthy individuals, bronchial parameters differed by sex, height, weight, and smoking history; male sex and increasing age were associated with wider lumens and thicker walls. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Emrich and Varga-Szemes in this issue.

Wnt5a-mediated autophagy contributes to the epithelial-mesenchymal transition of human bronchial epithelial cells during asthma.

BACKGROUND: The epithelial-mesenchymal transition (EMT) of human bronchial epithelial cells (HBECs) is essential for airway remodeling during asthma. Wnt5a has been implicated in various lung diseases, while its role in the EMT of HBECs during asthma is yet to be determined. This study sought to define whether Wnt5a initiated EMT, leading to airway remodeling through the induction of autophagy in HBECs. METHODS: Microarray analysis was used to investigate the expression change of WNT5A in asthma patients. In parallel, EMT models were induced using 16HBE cells by exposing them to house dust mites (HDM) or interleukin-4 (IL-4), and then the expression of Wnt5a was observed. Using in vitro gain- and loss-of-function approaches via Wnt5a mimic peptide FOXY5 and Wnt5a inhibitor BOX5, the alterations in the expression of the epithelial marker E-cadherin and the mesenchymal marker protein were observed. Mechanistically, the Ca2+/CaMKII signaling pathway and autophagy were evaluated. An autophagy inhibitor 3-MA was used to examine Wnt5a in the regulation of autophagy during EMT. Furthermore, we used a CaMKII inhibitor KN-93 to determine whether Wnt5a induced autophagy overactivation and EMT via the Ca2+/CaMKII signaling pathway. RESULTS: Asthma patients exhibited a significant increase in the gene expression of WNT5A compared to the healthy control. Upon HDM and IL-4 treatments, we observed that Wnt5a gene and protein expression levels were significantly increased in 16HBE cells. Interestingly, Wnt5a mimic peptide FOXY5 significantly inhibited E-cadherin and upregulated α-SMA, Collagen I, and autophagy marker proteins (Beclin1 and LC3-II). Rhodamine-phalloidin staining showed that FOXY5 resulted in a rearrangement of the cytoskeleton and an increase in the quantity of stress fibers in 16HBE cells. Importantly, blocking Wnt5a with BOX5 significantly inhibited autophagy and EMT induced by IL-4 in 16HBE cells. Mechanistically, autophagy inhibitor 3-MA and CaMKII inhibitor KN-93 reduced the EMT of 16HBE cells caused by FOXY5, as well as the increase in stress fibers, cell adhesion, and autophagy. CONCLUSION: This study illustrates a new link in the Wnt5a-Ca2+/CaMKII-autophagy axis to triggering airway remodeling. Our findings may provide novel strategies for the treatment of EMT-related diseases.

Loss of CFTR Reverses Senescence Hallmarks in SARS-CoV-2 Infected Bronchial Epithelial Cells.

SARS-CoV-2 infection has been recently shown to induce cellular senescence in vivo. A senescence-like phenotype has been reported in cystic fibrosis (CF) cellular models. Since the previously published data highlighted a low impact of SARS-CoV-2 on CFTR-defective cells, here we aimed to investigate the senescence hallmarks in SARS-CoV-2 infection in the context of a loss of CFTR expression/function. We infected WT and CFTR KO 16HBE14o-cells with SARS-CoV-2 and analyzed both the p21 and Ki67 expression using immunohistochemistry and viral and p21 gene expression using real-time PCR. Prior to SARS-CoV-2 infection, CFTR KO cells displayed a higher p21 and lower Ki67 expression than WT cells. We detected lipid accumulation in CFTR KO cells, identified as lipolysosomes and residual bodies at the subcellular/ultrastructure level. After SARS-CoV-2 infection, the situation reversed, with low p21 and high Ki67 expression, as well as reduced viral gene expression in CFTR KO cells. Thus, the activation of cellular senescence pathways in CFTR-defective cells was reversed by SARS-CoV-2 infection while they were activated in CFTR WT cells. These data uncover a different response of CF and non-CF bronchial epithelial cell models to SARS-CoV-2 infection and contribute to uncovering the molecular mechanisms behind the reduced clinical impact of COVID-19 in CF patients.

ALKBH5 Modulates Asthma Progression by Downregulating N6-methyladenosine Methylation.

Asthma is a chronic respiratory disease that is characterized by airway inflammation, excessive mucus production, and airway remodeling. Prevention and treatment for asthma is an urgent issue in clinical studies. In recent years, N6-methyladenosine methylation (m6A) has emerged as a promising regulatory approach involved in multiple diseases. ALKBH5 (alkB homolog 5) is a demethylase widely studied in disease pathologies. This work aimed to explore the regulatory mechanisms underlying the ALKBH5-regulated asthma. We established an interleukin-13 (IL-13)-stimulated cell model to mimic the in vitro inflammatory environment of asthma. ALKBH5 knockdown in bronchial epithelial cells was performed using siRNAs, and the knockdown efficacy was analyzed by quantitative PCR (qPCR). Cell viability and proliferation were measured by cell counting kit 8 (CCK-8) and colony formation assay. The ferroptosis was assessed by measuring the total iron, Fe2+, lipid reactive oxygen species (ROS), malondialdehyde (MDA), and superoxide dismutase (SOD) levels. The enrichment of N6-methyladenosine methylation (m6A) modification was detected by the MeRIP assay. Knockdown of ALKBH5 significantly elevated the survival and colony formation ability of bronchial epithelial cells in the IL-13 induction model. The levels of total iron, Fe2+, lipid ROS, and MDA were remarkedly elevated, and the SOD level was reduced in IL-13-induced bronchial epithelial cells, and depletion of ALKBH5 reversed these effects. Knockdown of ALKBH5 elevated the enrichment of m6A modification and expression of glutathione peroxidase 4 (GPX4). Knockdown of GPX4 abolished the pro-proliferation and anti-ferroptosis effects of siALKBH5. Knockdown of ALKBH5 improved the proliferation of bronchial epithelial cells and alleviated cell ferroptosis.

Zedoarondiol inhibits human bronchial smooth muscle cell proliferation through the CAV-1/PDGF signalling pathway.

Airway remodelling in lung diseases can be treated by inhibiting excessive smooth muscle cell proliferation. Zedoarondiol (Zed) is a natural compound isolated from the Chinese herb Curcuma longa. The caveolin-1 (CAV-1) is widely expressed in lung cells and plays a key role in platelet-derived growth factor (PDGF) signalling and cell proliferation. This study aims to investigate the effect of Zed on human bronchial smooth muscle cell (HBSMC) proliferation and explore its potential molecular mechanisms. We assessed the effect of Zed on the proliferation of PDGF-stimulated HBSMCs and performed proteomic analysis to identify potential molecular targets and pathways. CAV1 siRNA was used to validate our findings in vitro. In PDGF-stimulated HBSMCs, Zed significantly inhibited excessive proliferation of HBSMCs. Proteomic analysis of zedoarondiol-treated HBSMCs revealed significant enrichment of differentially expressed proteins in cell proliferation-related pathways and biological processes. Zed inhibition of HBSMC proliferation was associated with upregulation of CAV1, regulation of the CAV-1/PDGF pathway and inhibition of MAPK and PI3K/AKT signalling pathway activation. Treatment of HBSMCs with CAV1 siRNA partly reversed the inhibitory effect of Zed on HBSMC proliferation. Thus, this study reveals that zedoarondiol potently inhibits HBSMC proliferation by upregulating CAV-1 expression, highlighting its potential value in airway remodelling and related diseases.

[Navigational bronchoscopy with tranbronchial cryobiopsy in differential diagnosis of peripheral pulmonary lesions]. / Navigatsionnaya bronkhoskopiya s transbronkhial'noi kriobiopsiei v differentsial'noi diagnostike perifericheskikh obrazovanii legkikh.

OBJECTIVE: To evaluate the efficacy and safety of tranbronchial cryobiopsy (TBCB) with 1.9-mm and 1.1-mm cryoprobes in patients with peripheral pulmonary lesions (PPLs). MATERIAL AND METHODS: We analyzed 34 patients (mean age 60 years) with PPLs who underwent bronchoscopy with TBCB. Mean lesion size was 31.5 mm, upper lobe localization was predominant (47% of cases). CT signs of appropriate bronchus were identified in 79% (27/34) of cases. Manual branch tracking and virtual bronchoscopy (VB) were performed pre-procedurally, and radial endobronchial ultrasonography (rEBUS) was performed during bronchoscopy for accurate positioning of PPLs. TBCB was performed using 1.9-mm (n=19) or 1.1-mm (n=15) cryoprobes without fluoroscopic guidance. Incidence and severity of bleeding and pneumothorax were evaluated in all patients. RESULTS: Total efficacy of TBCB was 76.5% (26/34): 78.9% (15/19) for 1.9-mm cryoprobe and 73.3% (11/15) for 1.1-mm cryoprobe (p=0.702). Efficacy depended on the presence of CT signs of bronchus (presence - 94%, absence 14.3%, p<0.001) and PPL size (94% for PPL >30 mm and 58.8% for PPL <30 mm, p=0.016). Central probe position during rEBUS was associated with 94.7% diagnostic efficacy (18/19), adjacent probe position - 72.7% (8/11) (p=0.088). Bleeding grade 3 (Nasville) occurred in 5.8% (2/34) of cases, and no pneumothorax was observed. CONCLUSION: TBCB is an effective and safe diagnostic method for PPLs.

Establishing Air-Liquid Interface (ALI) Airway Culture Models for Infectious Disease Research.

Air-liquid interface (ALI) airway culture models serve as a powerful tool to emulate the characteristic features of the respiratory tract in vitro. These models are particularly valuable for studying emerging respiratory viral and bacterial infections. Here, we describe an optimized protocol to obtain the ALI airway culture models using normal human bronchial epithelial cells (NHBECs). The protocol outlined below enables the generation of differentiated mucociliary airway epithelial cultures by day 28 following exposure to air.

Tracheobronchial Foreign Body in Children with an Insidious Medical History.

This study explored the clinical features of tracheobronchial foreign bodies (TFB) in children lacking both a foreign body aspiration history and bronchial cut-off signs on imaging. This study was conducted between 2011 and 2021, including 45 children without a choking history or tracheal interruption on CT scans. Common symptoms were cough and wheezing (91.1%, 41 cases), followed by decreased breath sounds (55.6%, 25 cases), rales (48.9%, 22 cases), and wheezing (42.2%, 19 cases). Prior to TFB confirmation, bronchopneumonia was the prevalent diagnosis (88.9%, 40 cases). Vegetable matter was the most frequent foreign body type (75.6%, 34 cases), primarily located in the right main bronchus (31.1%) and left lower lobe bronchus (22.2%). TFB in children with obscure medical histories presents non-specifically, highlighting bronchoscopy's pivotal role in diagnosis and treatment. Key Words: Bronchoscope, Paediatrics, Tracheobronchial foreign body, Diagnosis.

Fractured Metallic Tracheostomy Tube: A Rare Presentation of Bronchial Foreign Body.

BACKGROUND: Tracheostomy is an important life-saving surgical procedure that could be used to secure the lower airway. It can however serve as a source of airway compromise when fragments from it are deposited. This condition must be diagnosed early enough, and appropriate intervention should be done to forestall potential morbidity and mortality. CASE REPORT: A 56-year-old tracheostomized patient presented to the accident and emergency department with a 4-hour history of sudden onset choking cough and labored breathing. The shaft of his tracheostomy tube (TT) was fractured and subsequently aspirated while he was attempting to remove and clean the inner tube that morning. He has used the TT for about 6 years and lost to follow-up clinic visits. The chest radiograph showed the metallic foreign body lodged within the trachea. He had an emergency rigid bronchoscopy via the tracheostomy stoma, and the object was retrieved. All respiratory symptoms subsequently resolved, and a check radiograph showed normal findings. CONCLUSION: Tracheostomy tube fracture and aspiration should be ruled out in every tracheostomized patient with sudden onset acute respiratory symptoms. Otolaryngologists must always emphasize the need for proper handling of TT, regular follow-up, and tube replacement when due.

Combination of transbronchoscopic oxygen insufflation and a digital chest drainage system in endobronchial occlusion: a hybrid technique for localization of fistula in intractable pneumothorax.

BACKGROUND: The management of intractable secondary pneumothorax poses a considerable challenge as it is often not indicated for surgery owing to the presence of underlying disease and poor general condition. While endobronchial occlusion has been employed as a non-surgical treatment for intractable secondary pneumothorax, its effectiveness is limited by the difficulty of locating the bronchus leading to the fistula using conventional techniques. This report details a case treated with endobronchial occlusion where the combined use of transbronchoscopic oxygen insufflation and a digital chest drainage system enabled location of the bronchus responsible for a prolonged air leak, leading to the successful treatment of intractable secondary pneumothorax. CASE PRESENTATION: An 83-year-old male, previously diagnosed with chronic hypersensitivity pneumonitis and treated with long-term oxygen therapy and oral corticosteroid, was admitted due to a pneumothorax emergency. Owing to a prolonged air leak after thoracic drainage, the patient was deemed at risk of developing an intractable secondary pneumothorax. Due to his poor respiratory condition, endobronchial occlusion with silicone spigots was performed instead of surgery. The location of the bronchus leading to the fistula was unclear on CT imaging. When the bronchoscope was wedged into each subsegmental bronchus and low-flow oxygen was insufflated, a digital chest drainage system detected a significant increase of the air leak only in B5a and B5b, thus identifying the specific location of the bronchus leading to the fistula. With the occlusion of those bronchi using silicone spigots, the air leakage decreased from 200 mL/min to 20 mL/min, and the addition of an autologous blood patch enabled successful removal of the drainage tube. CONCLUSION: The combination of transbronchoscopic oxygen insufflation with a digital chest drainage system can enhance the therapeutic efficacy of endobronchial occlusion by addressing the problems encountered in conventional techniques, where the ability to identify the leaking bronchus is dependent on factors such as the amount of escaping air and the location of the fistula.

[Comparative analysis of the effects of bronchial intubation and bronchial blocker on the outcomes of thoracoscopic surgery in infants and small children].

Objective: To compare the effects of bronchial intubation and blocker on the outcomes of thoracoscopic surgery in infants and small children. Methods: A total of 387 children, including 210 males and 177 females, aged (17.5±8.3) months, who underwent elective thoracoscopic surgery under general anesthesia in Children's Hospital Affiliated to Capital Institute of Pediatrics from January 2019 to August 2023 were retrospectively analyzed. The children were divided into bronchial intubation group and bronchial blocker group according to the intraoperative single-lung ventilation mode. After matching the age factor using the propensity score matching with nearest neighbor matching method, 258 cases were finally included in the bronchial intubation group, and 129 cases were included in the bronchial blocker group. The primary outcome was the incidence of postoperative pulmonary complications in two groups. The secondary outcomes included the incidence of intraoperative hypoxemia, postoperative oxygenation index, postoperative extubation time, the length of postoperative hospitalization and the total medical expenses during hospitalization between the two groups. Results: The incidence of postoperative pulmonary complications in the bronchial intubation group and bronchial blocker group was 15.5% (40/258) and 12.4% (16/129), the incidence of intraoperative hypoxemia was 20.2% (52/258) and 16.3% (21/129), the postoperative oxygen indexes were 306 (269, 323) and 311 (274, 336) mmHg (1 mmHg=0.133 kPa), the extubation time was (9.2±4.5) and (8.9±4.2) min, the length of postoperative hospitalization was (5.5±0.6) and (5.5±0.5) days and the total medical expenses were (34±6) and (35±6) thousand yuan, with no statistically significant differences between the two groups (all P>0.05). Conclusion: Both bronchial intubation and blocker can be used for one lung ventilation in thoracoscopic surgery for infants and small children, without affecting the postoperative outcomes.

[The use of bronchial occlusion test in a preterm infant with severe bronchopulmonary dysplasia complicated by severe lobar emphysema]. / æ”¯æ°”ç®¡å°å µè¯•éªŒåœ¨æ—©äº§å„¿é‡åº¦æ”¯æ°”ç®¡è‚ºå‘è‚²ä¸è‰¯ä¼´ä¸¥é‡è‚ºå¶æ°”è‚¿ä¸­çš„åº”ç”¨1例.

In infants with severe bronchopulmonary dysplasia (sBPD), severe pulmonary lobar emphysema may occur as a complication, contributing to significant impairment in ventilation. Clinical management of these infants is extremely challenging and some may require lobectomy to improve ventilation. However, prior to the lobectomy, it is very difficult to assess whether the remaining lung parenchyma would be able to sustain adequate ventilation postoperatively. In addition, preoperative planning and perioperative management are also quite challenging in these patients. This paper reports the utility of selective bronchial occlusion in assessing the safety and efficacy of lobectomy in a case of sBPD complicated by severe right upper lobar emphysema. Since infants with sBPD already have poor lung development and significant lung injury, lobectomy should be viewed as a non-traditional therapy and be carried out with extreme caution. Selective bronchial occlusion test can be an effective tool in assessing the risks and benefits of lobectomy in cases with sBPD and lobar emphysema. However, given the technical difficulty, successful application of this technique requires close collaboration of an experienced interdisciplinary team.

The Modulation of Respiratory Epithelial Cell Differentiation by the Thickness of an Electrospun Poly-ε-Carprolactone Mesh Mimicking the Basement Membrane.

The topology of the basement membrane (BM) affects cell physiology and pathology, and BM thickening is associated with various chronic lung diseases. In addition, the topology of commercially available poly (ethylene terephthalate) (PET) membranes, which are used in preclinical in vitro models, differs from that of the human BM, which has a fibrous and elastic structure. In this study, we verified the effect of BM thickness on the differentiation of normal human bronchial epithelial (NHBE) cells. To evaluate whether the thickness of poly-ε-carprolactone (PCL) mesh affects the differentiation of NHBE cells, cells were grown on thin- (6-layer) and thick-layer (80-layer) meshes consisting of electrospun PCL nanofibers using an air-liquid interface (ALI) cell culture system. It was found that the NHBE cells formed a normal pseudostratified epithelium composed of ciliated, goblet, and basal cells on the thin-layer PCL mesh; however, goblet cell hyperplasia was observed on the thick-layer PCL mesh. Differentiated NHBE cells cultured on the thick-layer PCL mesh also demonstrated increased epithelial-mesenchymal transition (EMT) compared to those cultured on the thin-layer PCL mesh. In addition, expression of Sox9, nuclear factor (NF)-κB, and oxidative stress-related markers, which are also associated with goblet cell hyperplasia, was increased in the differentiated NHBE cells cultured on the thick-layer PCL mesh. Thus, the use of thick electrospun PCL mesh led to NHBE cells differentiating into hyperplastic goblet cells via EMT and the oxidative stress-related signaling pathway. Therefore, the topology of the BM, for example, thickness, may affect the differentiation direction of human bronchial epithelial cells.

Tyndallized bacteria prime bronchial epithelial cells to mount an effective innate immune response against infections.

Airway epithelium represents a physical barrier against toxic substances and pathogens but also presents pattern recognition receptors on the epithelial cells that detect pathogens leading to molecule release and sending signals that activate both the innate and adaptive immune responses. Thus, impaired airway epithelial function and poor integrity may increase the recurrence of infections. Probiotic use in respiratory diseases as adjuvant of traditional therapy is increasingly widespread. There is growing interest in the use of non-viable heat-killed bacteria, such as tyndallized bacteria (TB), due to safety concerns and to their immunomodulatory properties. This study explores in vitro the effects of a TB blend on the immune activation of airway epithelium. 16HBE bronchial epithelial cells were exposed to different concentrations of TB. Cell viability, TB internalization, TLR2 expression, IL-6, IL-8 and TGF-ßl expression/release, E-cadherin expression and wound healing were assessed. We found that TB were tolerated, internalized, increased TLR2, E-cadherin expression, IL-6 release and wound healing but decreased both IL-8 and TGF-ßl release. In conclusion, TB activate TLR2 pathway without inducing a relevant pro-inflammatory response and improve barrier function, leading to the concept that TB preserve epithelial homeostasis and could be used as strategy to prevent and to manage respiratory infection, exacerbations included.

Identifying vagal bronchopulmonary afferents mediating cough response to inhaled sulfur dioxide in mice.

Sulfur dioxide (SO2), a common environmental and industrial air pollutant, possesses a potent effect in eliciting cough reflex, but the primary type of airway sensory receptors involved in its tussive action has not been clearly identified. This study was carried out to determine the relative roles of three major types of vagal bronchopulmonary afferents [slowly adapting receptors (SARs), rapidly adapting receptors (RARs), and C-fibers] in regulating the cough response to inhaled SO2. Our results showed that inhalation of SO2 (300 or 600 ppm for 8 min) evoked an abrupt and intense stimulatory effect on bronchopulmonary C-fibers, which continued for the entire duration of inhalation challenge and returned toward the baseline in 1-2 min after resuming room air-breathing in anesthetized and mechanically ventilated mice. In stark contrast, the same SO2 inhalation challenge generated a distinct and consistent inhibitory effect on both SARs and phasic RARs; their phasic discharges synchronized with respiratory cycles during the baseline (breathing room air) began to decline progressively within 1-3 min after the onset of SO2 inhalation, ceased completely before termination of the 8-min inhalation challenge, and then slowly returned toward the baseline after >40 min. In a parallel study in awake mice, inhalation of SO2 at the same concentration and duration as that in the nerve recording experiments evoked cough responses in a pattern and time course similar to that observed in the C-fiber responses. Based on these results, we concluded that stimulation of vagal bronchopulmonary C-fibers is primarily responsible for triggering the cough response to inhaled SO2.NEW & NOTEWORTHY This study demonstrated that inhalation of a high concentration of sulfur dioxide, an irritant gas and common air pollutant, completely and reversibly inhibited the neural activities of both slowly adapting receptor and rapidly adapting receptor, two major types of mechanoreceptors in the lungs with their activities conducted by myelinated fibers. Furthermore, the results of this study suggested that stimulation of vagal bronchopulmonary C-fibers is primarily responsible for triggering the cough reflex responses to inhaled sulfur dioxide.