Search Results (49)

Particulate matter (PM) is a major component of ambient air pollution. PM exposure is linked to numerous adverse health effects, including chronic lung diseases. Air quality guidelines designed to regulate levels of ambient PM are currently based on the mass concentration of different particle sizes, independent of their origin and chemical composition. The objective of this study was to assess the relative hazardous effects of carbonaceous particles (soot), ammonium nitrate, ammonium sulfate, and copper oxide (CuO), which are standard components of ambient air, reflecting contributions from primary combustion, secondary inorganic constituents, and non-exhaust emissions (NEE) from vehicular traffic. Human epithelial cells representing bronchial (BEAS-2B) and alveolar locations (H441 and A549) in the airways, human lung fibroblasts (HFL-1), and rat precision-cut lung slices (PCLS) were exposed in submerged cultures to different concentrations of particles for 5–72 h. Following exposure, cell viability, metabolic activity, reactive oxygen species (ROS) formation, and inflammatory responses were analyzed. CuO and, to a lesser extent, soot reduced cell viability in a dose-dependent manner, increased ROS formation, and induced inflammatory responses. Ammonium nitrate and ammonium sulfate did not elicit any significant cytotoxic responses but induced immunomodulatory alterations at very high concentrations. Our findings demonstrate that secondary inorganic components of PM have a lower hazard cytotoxicity compared with combustion-derived and indicative NEE components, and alveolar epithelial cells are more sensitive to PM exposure. This information should help to inform which sources of PM to target and feed into improved, targeted air quality guidelines. Full article

In patients with aspirin-exacerbated respiratory disease (AERD), there is disparate regulation of prostaglandin E2 (PGE₂) and prostaglandin D₂ (PGD₂). Both prostanoids are synthesised by cyclooxygenase 1 (COX-1) and cyclooxygenase 2 (COX-2). However, while the basal synthesis of PGE₂ tends to decrease, that of PGD₂ increases in patients with AERD. Furthermore, both behave differently in response to the inhibitory action of NSAIDs on COX-1: PGE₂ levels decrease while PGD₂ increases. Increased PGD₂ release correlates with nasal, bronchial, and extra-pulmonary symptoms caused by aspirin in AERD. The proposed hypothesis establishes that the answer to this paradoxical dissociation can be found in the airway epithelium. This is based on the observation that reduced COX-2 mRNA and/or protein expression is associated with reduced PGE₂ synthesis in cultured fibroblast and epithelial cells from AERD compared to patients with asthma who are aspirin-tolerant and healthy subjects. The low production of PGE₂ by the airway epithelium in AERD results in an excessive release of alarmins (TSLP, IL-33), which in turn contributes to activating group 2 innate lymphoid cells (ILC2s) and PGD₂ synthesis by mast cells and eosinophils. Aspirin, by further increasing the diminished PGE₂ regulation capacity in AERD, leads to respiratory reactions associated with the surge in PGD₂ from mast cells and eosinophils. In summary, the downregulation of COX-2 and the subsequent low production of PGE₂ by airway cells account for the apparently paradoxical increased production of PGD₂ by mast cells and eosinophils at the baseline and after aspirin provocation in patients with AERD. A better understanding of the role of the airway epithelium would contribute to elucidating the mechanism of AERD. Full article

Idiopathic pulmonary fibrosis (IPF) is a pulmonary disease characterized by excessive extracellular matrix protein deposition in the lung interstitium, subsequently causing respiratory failure. IPF still has a high medical unmet requirement due to the lack of effective treatments to inhibit disease progression. The etiology of IPF remains unclear, but mitochondrial dysfunction is considered to be associated with IPF development. Therefore, targeting mitochondrial abnormalities would be a promising strategy for treating IPF. Recently, exogenous mitochondrial transplantation has been beneficial for treating mitochondrial dysfunction. The current study aimed to examine the therapeutic effect of mitochondrial transplantation on IPF in vitro and in vivo. Mitochondria were isolated from human umbilical cord mesenchymal stem cells, referred to as PN-101. Human lung fibroblasts and human bronchial epithelial cells were exposed to transforming growth factor-β, followed by PN-101 treatment to determine the in vitro efficacy of mitochondrial transplantation. An IPF mouse model established by a single intratracheal instillation of bleomycin was utilized to determine the in vivo efficacy of the intravenously treated mitochondria. PN-101 attenuated mitochondrial damage, inhibited EMC production, and suppressed epithelial-to-mesenchymal transition in vitro. Additionally, intravenous PN-101 administration alleviated bleomycin-induced fibrotic processes in the IPF mouse model with a therapeutic context. Our data indicate that PN-101 is a novel and potential therapeutic agent for IPF. Full article

Cold atmospheric plasma (CAP) devices generate reactive oxygen and nitrogen species, have antimicrobial and antiviral properties, but also affect the molecular and cellular mechanisms of eukaryotic cells. The aim of this study is to investigate CAP treatment in the upper respiratory tract (URT) to reduce the incidence of ventilator-associated bacterial pneumonia (especially superinfections with multi-resistant pathogens) or viral infections (e.g., COVID-19). For this purpose, the surface-microdischarge-based plasma intensive care (PIC) device was developed by terraplasma medical GmbH. This study analyzes the safety aspects using in vitro assays and molecular characterization of human oral keratinocytes (hOK), human bronchial–tracheal epithelial cells (hBTE), and human lung fibroblasts (hLF). A 5 min CAP treatment with the PIC device at the “throat” and “subglottis” positions in the URT model did not show any significant differences from the untreated control (ctrl.) and the corresponding pressurized air (PA) treatment in terms of cell morphology, viability, apoptosis, DNA damage, and migration. However, pro-inflammatory cytokines (MCP-1, IL-6, and TNFα) were induced in hBTE and hOK cells and profibrotic molecules (collagen-I, FKBP10, and αSMA) in hLF at the mRNA level. The use of CAP in the oropharynx may make an important contribution to the recovery of intensive care patients. The results indicate that a 5 min CAP treatment in the URT with the PIC device does not cause any cell damage. The extent to which immune cell activation is induced and whether it has long-term effects on the organism need to be carefully examined in follow-up studies in vivo. Full article

Oxidative stress in the human lung is caused by both internal (e.g., inflammation) and external stressors (smoking, pollution, and infection) to drive pathology in a number of lung diseases. Cellular damage caused by oxidative damage is reversed by several pathways, one of which is the antioxidant response. This response is regulated by the transcriptional factor NRF2, which has the ability to regulate the transcription of more than 250 genes. In disease, this balance is overwhelmed, and the cells are unable to return to homeostasis. Several pharmacological approaches aim to improve the antioxidant capacity by inhibiting the interaction of NRF2 with its key cytosolic inhibitor, KEAP1. Here, we evaluate an alternative approach by overexpressing NRF2 from chemically modified RNAs (cmRNAs). Our results demonstrate successful expression of functional NRF2 protein in human cell lines and primary cells. We establish a kinetic transcriptomic profile to compare antioxidant response gene expression after treatment of primary human bronchial epithelial cells with either KEAP1 inhibitors or cmRNAs. The key gene signature is then applied to primary human lung fibroblasts and alveolar macrophages to uncover transcriptional preferences in each cell system. This study provides a foundation for the understanding of NRF2 dynamics in the human lung and provides initial evidence of alternative ways for pharmacological interference. Full article

Bronchial asthma is characterized by airway inflammation, airway hyperresponsiveness, and reversible airway obstruction. Eosinophils contribute to the pathogenesis of airway disease mainly by releasing eosinophil-specific granules, lipid mediators, superoxide anions, and their DNA. Type-2 cytokines such as interleukin (IL)-4 and IL-13 also play roles in the development of bronchial asthma. Among these cytokines, IL-4 is involved in T-cell differentiation, B-cell activation, B-cell differentiation into plasma cells, and the production of immunoglobulin E. Although IL-13 has similar effects to IL-4, IL-13 mainly affects structural cells, such as epithelial cells, smooth muscle cells, and fibroblasts. IL-13 induces the differentiation of goblet cells that produce mucus and induces the airway remodeling, including smooth muscle hypertrophy. IL-4 and IL-13 do not directly activate the effector functions of eosinophils; however, they can induce eosinophilic airway inflammation by upregulating the expression of vascular cell adhesion molecule-1 (for adhesion) and CC chemokine receptor 3 ligands (for migration). Dupilumab, a human anti-IL-4 receptor α monoclonal antibody that inhibits IL-4 and IL-13 signaling, decreases asthma exacerbations and mucus plugs and increases lung function in moderate to severe asthma. In addition, dupilumab is effective for chronic rhinosinusitis with nasal polyps and for atopic dermatitis, and IL-4/IL-13 blocking is expected to suppress allergen sensitization, including transcutaneous sensitization and atopic march. Full article

The use of nanoparticle systems for the controlled release of growth factors is a promising approach to mimicking of the biochemical environment of native tissues in tissue engineering. However, sustaining growth factor release inside an appropriate therapeutic window is a challenge, particularly in bioprinted scaffolds. In this study, a chitosan-coated alginate-based nanoparticle system loaded with hepatocyte growth factor was developed and then incorporated into bioprinted scaffolds. The release kinetics were investigated with a focus on identifying the impact of the chitosan coating and culture conditions. Our results demonstrated that the chitosan coating decreased the release rate and lessened the initial burst release, while culturing in dynamic conditions had no significant impact compared to static conditions. The nanoparticles were then incorporated into bioinks at various concentrations, and scaffolds with a three-dimensional (3D) structure were bioprinted from the bioinks containing human pulmonary fibroblasts and bronchial epithelial cells to investigate the potential use of a controlled release system in respiratory tissue engineering. It was found that the bioink loaded with a concentration of 4 µg/mL of nanoparticles had better printability compared to other concentrations, while the mechanical stability of the scaffolds was maintained over a 14-day culture period. The examination of the incorporated cells demonstrated a high degree of viability and proliferation with visualization of the beginning of an epithelial barrier layer. Taken together, this study demonstrates that a chitosan-coated alginate-based nanoparticle system allows the sustained release of growth factors in bioprinted respiratory tissue scaffolds. Full article

Background and Objectives: Chronic inflammation due to Pseudomonas aeruginosa (PA) infection in people with cystic fibrosis (CF) remains a concerning issue in the wake of modulator therapy initiation. Given the perpetuating cycle of colonization, infection, chronic inflammation, and recurrent injury to the lung, there are increases in the risk for mortality in the CF population. We have previously shown that fibroblast growth factor (FGF) 23 can exaggerate transforming growth factor (TGF) beta-mediated bronchial inflammation in CF. Our study aims to shed light on whether FGF23 signaling also plays a role in PA infection of the CF bronchial epithelium. Materials and Methods: CF bronchial epithelial cells were pretreated with FGF23 or inhibitors for FGF receptors (FGFR) and then infected with different PA isolates. After infection, immunoblot analyses were performed on these samples to assess the levels of phosphorylated phospholipase C gamma (PLCγ), total PLCγ, phosphorylated extracellular signal-regulated kinase (ERK), and total ERK. Additionally, the expression of FGFRs and interleukins at the transcript level (RT-qPCR), as well as production of interleukin (IL)-6 and IL-8 at the protein level (ELISA) were determined. Results: Although there were decreases in isoform-specific FGFRs with increases in interleukins at the mRNA level as well as phosphorylated PLCγ and the production of IL-8 protein with PA infection, treatment with FGF23 or FGFR blockade did not alter downstream targets such as IL-6 and IL-8. Conclusions: FGF23 signaling does not seem to modulate the PA-mediated inflammatory response of the CF bronchial epithelium. Full article

Accumulating evidence suggests that an important role is played by electric signals in modifying cell behaviour during developmental, regenerative and pathological processes. However, their role in asthma has not yet been addressed. Bronchial fibroblasts have recently been identified having important roles in asthma development. Therefore, we adapted an experimental approach based on the lineages of human bronchial fibroblasts (HBF) derived from non-asthmatic (NA) donors and asthmatic (AS) patients to elucidate whether their reactivity to direct current electric fields (dcEF) could participate in the asthmatic process. The efficient responsiveness of NA HBF to an electric field in the range of 2–4 V/cm was illustrated based on the perpendicular orientation of long axes of the cells to the field lines and their directional movement towards the anode. These responses were related to the activity of TGF-β signalling, as the electrotaxis and re-orientation of NA HBF polarity was impaired by the inhibitors of canonical and non-canonical TGF-β-dependent pathways. A similar tendency towards perpendicular cell-dcEF orientation was observed for AS HBF. However, their motility remained insensitive to the electric field applied at 2–4 V/cm. Collectively, these observations demonstrate the sensitivity of NA HBF to dcEF, as well as the inter-relations between this parameter and the canonical and non-canonical TGF-β pathways, and the differences between the electrotactic responses of NA and AS HBF point to the possible role of their dcEFs in desensitisation in the asthmatic process. This process may impair the physiologic behaviour of AS HBF functions, including cell motility, ECM deposition, and contractility, thus promoting bronchial wall remodelling, which is a characteristic of bronchial asthma. Full article

Asthma is a common chronic respiratory disease that affects millions of people worldwide, and its prevalence continues to increase. Vitamin D has been proposed as a potential environmental factor in asthma pathogenesis, due to its immunomodulatory effects. This systematic review aimed to evaluate the effect of vitamin D supplementation in order to prevent airway remodeling in asthmatic patients. Four electronic databases, namely PubMed, Embase, Clinical trails.gov, and CINAHL, were thoroughly searched to conduct a comprehensive literature review. The International Prospective Register of Systematic Reviews (CRD42023413798) contains a record of the registered protocol. We identified 9447 studies during the initial search; 9 studies (0.1%) met the inclusion criteria and were included in the systematic review. All included studies were experimental studies that investigated the impact of vitamin D supplementation on airway remodeling in asthma. The studies included in this review suggest that vitamin D inhibits airway smooth muscle cell contraction and remodeling, reduces inflammation, regulates collagen synthesis in the airways, and modulates the action of bronchial fibroblasts. However, one study suggests that TGF-β1 can impair vitamin D-induced and constitutive airway epithelial host defense mechanisms. Overall, vitamin D appears to have a potential role in the prevention and management of asthma. Full article

The airway wall remodeling observed in asthma is associated with subepithelial fibrosis and enhanced activation of human bronchial fibroblasts (HBFs) in the fibroblast to myofibroblast transition (FMT), induced mainly by transforming growth factor-β (TGF-β). The relationships between asthma severity, obesity, and hyperlipidemia suggest the involvement of peroxisome proliferator-activated receptors (PPARs) in the remodeling of asthmatic bronchi. In this study, we investigated the effect of PPARδ ligands (GW501516 as an agonist, and GSK0660 as an antagonist) on the FMT potential of HBFs derived from asthmatic patients cultured in vitro. This report shows, for the first time, the inhibitory effect of a PPARδ agonist on the number of myofibroblasts and the expression of myofibroblast-related markers—α-smooth muscle actin, collagen 1, tenascin C, and connexin 43—in asthma-related TGF-β-treated HBF populations. We suggest that actin cytoskeleton reorganization and Smad2 transcriptional activity altered by GW501516 lead to the attenuation of the FMT in HBF populations derived from asthmatics. In conclusion, our data demonstrate that a PPARδ agonist stimulates antifibrotic effects in an in vitro model of bronchial subepithelial fibrosis. This suggests its potential role in the development of a possible novel therapeutic approach for the treatment of subepithelial fibrosis during asthma. Full article

The progression of smoking-related diseases is characterized by macrophage-mediated inflammation, which is responsible for an increased expression of proinflammatory cytokines and galectins, molecules that bind specifically to β-galactoside sugars. This study aimed to assess the anti-inflammatory and antioxidant effects of a broad selection of differently lactose-modified hyaluronic acids (HA) named HYLACH^®, which are able to bind proinflammatory galectins. The best HYLACH ligands for Gal-3 were selected in silico and their activities were tested in vitro on primary human bronchial fibroblasts obtained from smokers and inflamed with the conditioned medium of activated U937 monocytes. Changes in cell viability, ROS generation, proinflammatory mediators, and MMP expression, at both gene and protein levels, were analyzed. The in silico results show that HYLACH with a percentage of lactosylation of 10–40% are the best ligands for Gal-3. The in vitro study revealed that HYLACH compounds with 10, 20, and 40% lactosylation (HYLACH-1-2-3) administrated to inflamed cell cultures counteracted the oxidative damage and restored gene and protein expression for IL-1β, TNF-α, IL-6, Gal-1, Gal-3, and MMP-3 to near baseline values. The evidence that HYLACH attenuated macrophage-induced inflammation, inhibited MMP expression, and exhibited antioxidative effects provide an initial step toward the development of a therapeutic treatment suitable for smoking-related diseases. Full article

Mechanical ventilation (MV) used in patients with acute lung injury (ALI) induces lung inflammation and causes fibroblast proliferation and excessive collagen deposition—a process termed epithelial–mesenchymal transition (EMT). Phosphoinositide 3-kinase-γ (PI3K-γ) is crucial in modulating EMT during the reparative phase of ALI; however, the mechanisms regulating the interactions among MV, EMT, and PI3K-γ remain unclear. We hypothesized that MV with or without bleomycin treatment would increase EMT through the PI3K-γ pathway. C57BL/6 mice, either wild-type or PI3K-γ-deficient, were exposed to 6 or 30 mL/kg MV for 5 h after receiving 5 mg/kg AS605240 intraperitoneally 5 days after bleomycin administration. We found that, after bleomycin exposure in wild-type mice, high-tidal-volume MV induced substantial increases in inflammatory cytokine production, oxidative loads, Masson’s trichrome staining level, positive staining of α-smooth muscle actin, PI3K-γ expression, and bronchial epithelial apoptosis (p < 0.05). Decreased respiratory function, antioxidants, and staining of the epithelial marker Zonula occludens-1 were also observed (p < 0.05). MV-augmented bleomycin-induced pulmonary fibrogenesis and epithelial apoptosis were attenuated in PI3K-γ-deficient mice, and we found pharmacological inhibition of PI3K-γ activity through AS605240 (p < 0.05). Our data suggest that MV augmented EMT after bleomycin-induced ALI, partially through the PI3K-γ pathway. Therapy targeting PI3K-γ may ameliorate MV-associated EMT. Full article

Inflammation is closely related to asthma and its defining feature: airway remodeling. The aim of this study was to determine the effects of extracts of normal (NR) and transformed (TR) Leonotis nepetifolia roots on respiratory cells and against the gingival epithelium. Extracts from NR and TR roots were added to lung fibroblast, bronchial epithelial and gingival fibroblast cell lines, in the presence of HRV-16 infection, to determine their impact on inflammation. The expression of inflammatory cytokines (IL-6, IL-1β, GM-CSF and MCAF) as well as total thiol contents were assessed. The TR extract inhibited rhinovirus-induced IL-6 and IL-1β expression in all tested airway cells (p < 0.05). Additionally, the extract decreased GM-CSF expression in bronchial epithelial cells. The tested extracts had positive effects on total thiol content in all tested cell lines. The TR root extract demonstrated wound healing potential. While both tested extracts exhibited anti-inflammatory and antioxidative effects, they were stronger for the TR extract, possibly due to higher concentrations of beneficial metabolites such as phenols and flavonoids. Additionally, wound healing activity was demonstrated for the TR root extract. These results suggest that TR root extract may become a promising therapeutic agent in the future. Full article

In vitro airway models are increasingly important for pathomechanistic analyses of respiratory diseases. Existing models are limited in their validity by their incomplete cellular complexity. We therefore aimed to generate a more complex and meaningful three-dimensional (3D) airway model. Primary human bronchial epithelial cells (hbEC) were propagated in airway epithelial cell growth (AECG) or PneumaCult ExPlus medium. Generating 3D models, hbEC were airlifted and cultured on a collagen matrix with donor-matched bronchial fibroblasts for 21 days comparing two media (AECG or PneumaCult ALI (PC ALI)). 3D models were characterized by histology and immunofluorescence staining. The epithelial barrier function was quantified by transepithelial electrical resistance (TEER) measurements. The presence and function of ciliated epithelium were determined by Western blot and microscopy with high-speed camera. In 2D cultures, an increased number of cytokeratin 14-positive hbEC was present with AECG medium. In 3D models, AECG medium accounted for high proliferation, resulting in hypertrophic epithelium and fluctuating TEER values. Models cultured with PC ALI medium developed a functional ciliated epithelium with a stable epithelial barrier. Here, we established a 3D model with high in vivo–in vitro correlation, which has the potential to close the translational gap for investigations of the human respiratory epithelium in pharmacological, infectiological, and inflammatory research. Full article