Endocrine disrupting chemicals in Italian drinking water systems: Insights from a three-year investigation combining chemical and effect-based tools

Drinking water quality can be compromised by endocrine-disrupting chemicals (EDCs). Three phenolic compounds [bisphenol A (BPA), nonylphenol (NP), and 4-octylphenol (OP)] and three hormones [17β-estradiol (E2), estrone (E1), and 17α-ethinylestradiol (EE2)] were analyzed as EDCs potentially occurring in source and drinking water from three full-scale drinking water treatment plants (DWTPs) in the Romagna area (Italy) by a combined approach of HPLC-MS/MS target analysis and effect-based tests for estrogenicity and genotoxicity. The EDC removal efficiency was evaluated at different steps along the treatment process in the most advanced DWTP. NP prevailed in all samples, followed by BPA. Sporadic contamination by OP and E1/E2 appeared only in the source waters; EE2 was never detected. No estrogenic or genotoxic activity was found, except for two samples showing estrogenicity well below the effect-based trigger value suggested for drinking water safety (0.9 ng/L EEQ). BPA and NP levels were largely below the threshold value; however, increases were observed after the intermediate steps of the treatment chain. The good quality of the water relied on the last step, i.e. the activated carbon filtration. DWTPs may represent an extra source of EDCs and monitoring chemical occurrence at all steps of the process is advisable to improve efficiency.

Impaired autophagy in the lower airways and lung parenchyma in stable COPD

Background

There is increasing evidence of autophagy activation in COPD, but its role is complex and probably regulated through cell type-specific mechanisms. This study aims to investigate the autophagic process at multiple levels within the respiratory system, using different methods to clarify conflicting results reported so far.

Methods

This cross-sectional study was performed on bronchial biopsies and peripheral lung samples obtained from COPD patients (30 and 12 per sample type, respectively) and healthy controls (25 and 22 per sample type, respectively), divided by smoking history. Subjects were matched for age and smoking history. We analysed some of the most important proteins involved in autophagosome formation, such as LC3 and p62, as well as some molecules essential for lysosome function, such as lysosome-associated membrane protein 1 (LAMP1). Immunohistochemistry was used to assess the autophagic process in both sample types. ELISA and transcriptomic analysis were performed on lung samples.

Results

We found increased autophagic stimulus in smoking subjects, regardless of respiratory function. This was revealed by immunohistochemistry through a significant increase in LC3 (p<0.01) and LAMP1 (p<0.01) in small airway bronchiolar epithelium, alveolar septa and alveolar macrophages. Similar results were obtained in bronchial biopsy epithelium by evaluating LC3B (p<0.05), also increased in homogenate lung tissue using ELISA (p<0.05). Patients with COPD, unlike the others, showed an increase in p62 by ELISA (p<0.05). No differences were found in transcriptomics analysis.

Conclusions

Different techniques, applied at post-transcriptional level, confirm that cigarette smoke stimulates autophagy at multiple levels inside the respiratory system, and that autophagy failure may characterise COPD.

Autophagy/Mitophagy in Airway Diseases: Impact of Oxidative Stress on Epithelial Cells

Autophagy is the key process by which the cell degrades parts of itself within the lysosomes. It maintains cell survival and homeostasis by removing molecules (particularly proteins), subcellular organelles, damaged cytoplasmic macromolecules, and by recycling the degradation products. The selective removal or degradation of mitochondria is a particular type of autophagy called mitophagy. Various forms of cellular stress (oxidative stress (OS), hypoxia, pathogen infections) affect autophagy by inducing free radicals and reactive oxygen species (ROS) formation to promote the antioxidant response. Dysfunctional mechanisms of autophagy have been found in different respiratory diseases such as chronic obstructive lung disease (COPD) and asthma, involving epithelial cells. Several existing clinically approved drugs may modulate autophagy to varying extents. However, these drugs are nonspecific and not currently utilized to manipulate autophagy in airway diseases. In this review, we provide an overview of different autophagic pathways with particular attention on the dysfunctional mechanisms of autophagy in the epithelial cells during asthma and COPD. Our aim is to further deepen and disclose the research in this direction to stimulate the develop of new and selective drugs to regulate autophagy for asthma and COPD treatment.

Extracellular vesicles from PBDE-47 treated M(LPS) THP-1 macrophages modulate the expression of markers of epithelial integrity, EMT, inflammation and muco-secretion in ALI culture of airway epithelium

AIMS

The lung epithelial cells form a physical barrier to the external environment acting as the first line of defence against potentially harmful environmental stimuli. These cells interact with several other cellular components, of which macrophages are some of the most relevant. We analysed the effects of the PBDE-47 on the microRNA cargo of THP-1 macrophage like derived small Extracellular Vesicles (sEVs) and the effects on A549 lung epithelial cells.

MAIN METHODS

sEVs from M(LPS) THP-1 macrophage-like cells after PBDE-47 treatment (sEVs^PBDE+LPS) were characterized by nanoparticle tracking analysis and their microRNA cargo studied by qPCR. Confocal microscopy was applied to study sEVs cellular uptake by A549 cells. The expression of tight junctions (TJs), adhesion molecules, inflammation markers and mucus production in A549 cultured in air liquid interface (ALI) conditions were studied by Real Time PCR and confocal microscopy.

KEY FINDINGS

sEVs^PBDE+LPS microRNA cargo analysis showed that the PBDE-47 modulated the expression of the miR-15a-5p, miR29a-3p, miR-143-3p and miR-122-5p. Furthermore, ALI cultured A549 cells incubated with sEVs^PBDE+LPS showed that zonula occludens-1 (p ≤ 0.04), claudin (p ≤ 0.02), E-cadherin (p ≤ 0.006) and Vimentin (p ≤ 0.0008) mRNAs were increased in A549 cells after sEVs^PBDE+LPS treatment. Indeed, Interleukin (IL)-8 (p ≤ 0.008) and mucin (MUC5AC and MUC5B) (p ≤ 0.03 and p ≤ 0.0001) mRNA expression were up- and down-regulated, respectively.

SIGNIFICANCE

PBDE-47 treated macrophages secrete sEVs with altered microRNA cargo that affect the mRNA expression of TJs, adhesion molecules, cytokines and EMT markers damaging the normal function of the lung epithelium, potentially contributing to the development of lung diseases.

Non-Coding RNAs in Airway Diseases: A Brief Overview of Recent Data

Inflammation of the human lung is mediated in response to different stimuli (e.g., physical, radioactive, infective, pro-allergenic, or toxic) such as cigarette smoke and environmental pollutants. These stimuli often promote an increase in different inflammatory activities in the airways, manifesting themselves as chronic diseases (e.g., allergic airway diseases, asthma chronic bronchitis/chronic obstructive pulmonary disease, or even lung cancer). Non-coding RNA (ncRNAs) are single-stranded RNA molecules of few nucleotides that regulate the gene expression involved in many cellular processes. ncRNA are molecules typically involved in the reduction of translation and stability of the genes of mRNAs s. They regulate many biological aspects such as cellular growth, proliferation, differentiation, regulation of cell cycle, aging, apoptosis, metabolism, and neuronal patterning, and influence a wide range of biologic processes essential for the maintenance of cellular homeostasis. The relevance of ncRNAs in the pathogenetic mechanisms of respiratory diseases has been widely established and in the last decade many papers were published. However, once their importance is established in pathogenetic mechanisms, it becomes important to further deepen the research in this direction. In this review we describe several of most recent knowledge concerning ncRNA (overall miRNAs) expression and activities in the lung.

Overview of the Mechanisms of Oxidative Stress: Impact in Inflammation of the Airway Diseases

Inflammation of the human lung is mediated in response to different stimuli (e.g., physical, radioactive, infective, pro-allergenic or toxic) such as cigarette smoke and environmental pollutants. They often promote an increase in inflammatory activities in the airways that manifest themselves as chronic diseases (e.g., allergic airway diseases, asthma, chronic bronchitis/chronic obstructive pulmonary disease (COPD) or even lung cancer). Increased levels of oxidative stress (OS) reduce the antioxidant defenses, affect the autophagy/mitophagy processes, and the regulatory mechanisms of cell survival, promoting inflammation in the lung. In fact, OS potentiate the inflammatory activities in the lung, favoring the progression of chronic airway diseases. OS increases the production of reactive oxygen species (ROS), including superoxide anions (O₂^-), hydroxyl radicals (OH) and hydrogen peroxide (H₂O₂), by the transformation of oxygen through enzymatic and non-enzymatic reactions. In this manner, OS reduces endogenous antioxidant defenses in both nucleated and non-nucleated cells. The production of ROS in the lung can derive from both exogenous insults (cigarette smoke or environmental pollution) and endogenous sources such as cell injury and/or activated inflammatory and structural cells. In this review, we describe the most relevant knowledge concerning the functional interrelation between the mechanisms of OS and inflammation in airway diseases.

Impact of Air Pollution in Airway Diseases: Role of the Epithelial Cells (Cell Models and Biomarkers)

Biomedical research is multidisciplinary and often uses integrated approaches performing different experimental models with complementary functions. This approach is important to understand the pathogenetic mechanisms concerning the effects of environmental pollution on human health. The biological activity of the substances is investigated at least to three levels using molecular, cellular, and human tissue models. Each of these is able to give specific answers to experimental problems. A scientific approach, using biological methods (wet lab), cell cultures (cell lines or primary), isolated organs (three-dimensional cell cultures of primary epithelial cells), and animal organisms, including the human body, aimed to understand the effects of air pollution on the onset of diseases of the respiratory system. Biological methods are divided into three complementary models: in vitro, ex vivo, and in vivo. In vitro experiments do not require the use of whole organisms (in vivo study), while ex vivo experiments use isolated organs or parts of organs. The concept of complementarity and the informatic support are useful tools to organize, analyze, and interpret experimental data, with the aim of discussing scientific notions with objectivity and rationality in biology and medicine. In this scenario, the integrated and complementary use of different experimental models is important to obtain useful and global information that allows us to identify the effect of inhaled pollutants on the incidence of respiratory diseases in the exposed population. In this review, we focused our attention on the impact of air pollution in airway diseases with a rapid and descriptive analysis on the role of epithelium and on the experimental cell models useful to study the effect of toxicants on epithelial cells.

Endotyping Seasonal Allergic Rhinitis in Children: A Cluster Analysis

Background

Seasonal Allergic Rhinitis (SAR) is a heterogeneous inflammatory disease. We hypothesized that a cluster analysis based on the evaluation of cytokines in nasal lavage (NL) could characterize distinctive SAR endotypes in children.

Methods

This cross-sectional study enrolled 88 children with SAR. Detailed medical history was obtained by well-trained physicians. Quality of life and sleep quality were assessed through standardized questionnaires [Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) and Pittsburgh Sleep Quality Index (PSQI) respectively]. Children were grouped through K-means clustering using Interleukin (IL)-5, IL-17, IL-23, and Interferon (INF)-γ in NL.

Results

Out of the 88 patients enrolled, 80 were included in the cluster analysis, which revealed three SAR endotypes. Cluster 1 showed lower levels of IL-5 and IL-17 and intermediate levels of IL-23 and IFN-γ; Cluster 2 had higher levels of IL-5 and intermediate levels of IL-17, IL-23, and IFN-γ; Cluster 3 showed higher levels of IL-17, IL-23, and IFN-γ and intermediate levels of IL-5. Cluster 1 showed intermediate values of nasal pH and nasal nitric oxide (nNO), and a lower percentage of neutrophils at nasal cytology than Clusters 2 and 3. Cluster 2 had a lower level of nasal pH, a higher nNO, higher scores in the ocular domain of PRQLQ, and worse sleep quality than Clusters 1 and 3. Cluster 3 showed a higher percentage of neutrophils at nasal cytology than Clusters 1 and 2.

Conclusions

Our study identified three endotypes based on the evaluation of cytokines in NL, highlighting that childhood SAR is characterized by heterogeneous inflammatory cytokines.

Airway epithelial dysfunction and mesenchymal transition in chronic obstructive pulmonary disease: Role of Oct-4

The airway epithelium is a dynamic tissue that undergoes slow but constant renewal. Dysregulation of airway epithelial function related to cigarette smoke exposure plays an important role in the pathophysiology of COPD. Oct4 is a transcription factor responsible for maintaining cellular self-renewal and regeneration, and CD146 and CD105/Endoglin are adhesion molecules involved in cell proliferation, differentiation, epithelial-mesenchymal-transition and tissue remodeling. Bronchial biopsy specimens (BBs) were obtained from 7 healthy controls (HC) and 10 COPD and subjected to paraffin embedding; BBs from HC were also used for epithelial cell expansion and pHBEC/ALI (air-liquid interface) culture. pHBEC/ALI were exposed to cigarette smoke extract (CSE) for 7, 14 and 21 days. In BBs, Oct4, CD146 and CD105 were evaluated by immunohistochemistry. In pHBEC/ALI, the expression of Oct4, CD146, CD105 and acetyl-αtubulin was evaluated by Western Blot, MUC5AC and IL-8 measurements by ELISA. The Oct4 epithelial immunoreactivity was lower in COPD than in HC, whilst CD146 and CD105 expression was higher in COPD than in HC. In pHBEC/ALI, Transepithelial Electrical Resistance values, measured over 7 to 21 days of differentiation, decreased by 18% (2.5% CSE) and 29% (5% CSE) compared to untreated samples. Oct4 and acetyl-αtubulin were induced after one-week differentiation and downregulated by CSE in reconstituted epithelium; CD146, CD105, MUC5AC and IL-8 were increased by CSE. Oct4 de-regulation and CD146 and CD105 overexpression, induced by cigarette smoke exposure, might play a role in airway epithelial dysfunction by causing changes in self-renewal and mesenchymal transition mechanisms, leading to alteration of epithelium homeostasis and abnormal tissue remodeling involved in progression of COPD.

Expression/Activation of PAR-1 in Airway Epithelial Cells of COPD Patients: Ex Vivo/In Vitro Study

The role of PAR-1 expression and activation was described in epithelial cells from the central and distal airways of COPD patients using an ex vivo/in vitro model. PAR-1 immunoreactivity was studied in epithelial cells from surgical specimens of the central and distal airways of COPD patients and healthy control (HC). Furthermore, PAR-1 expression and activation were measured in both the human bronchial epithelial cell line (16HBE) and normal human bronchial epithelial cells (NHBEs) exposed to cigarette smoke extract (CSE) (10%) or thrombin. Finally, cell proliferation, apoptosis, and IL-8 release were detected in stimulated NHBEs. We identified higher levels of PAR-1 expression/activation in epithelial cells from the central airways of COPD patients than in HC. Active PAR-1 increased in epithelial cells from central and distal airways of COPD, with higher levels in COPD smokers (correlated with pack-years) than in COPD ex-smokers. 16HBE and NHBEs exposed to CSE or thrombin showed increased levels of active PAR-1 (localized in the cytoplasm) than baseline conditions, while NHBEs treated with thrombin or CSE showed increased levels of IL-8 proteins, with an additional effect when used in combination. Smoking habits generate the upregulation of PAR-1 expression/activation in airway epithelial cells, and promoting IL-8 release might affect the recruitment of infiltrating cells in the airways of COPD patients.

PBDEs affect inflammatory and oncosuppressive mechanisms via the EZH2 methyltransferase in airway epithelial cells

AIMS

We aimed to investigate the effect of PBDEs (47, 99, 209) on cellular events involved in epigenetic modification, inflammation, and epithelial mesenchymal transition (EMT).

MATERIALS AND METHODS

We studied: 1) ERK1/2 phosphorylation; 2) Enhancer of Zester Homolog 2 (EZH2); 3) Histone H3 tri-methylated in lysine 27 (H3K27me3); 4) K-RAS; 5) silencing disabled homolog 2-interacting protein gene (DAB2IP), 6) let-7a; 7) Muc5AC/Muc5B, and 8) IL-8 in a 3D in vitro model of epithelium obtained with primary Normal Human Bronchial Epithelial cells (pNHBEs) or A549 cell line, chronically exposed to PBDEs (47, 99, 209).

KEY FINDINGS

PBDEs (10 nM, 100 nM and 1 μM) increased ERK1/2 phosphorylation, and EZH2, H3K27me3, and K-RAS protein expression, while decreased DAB2IP and Let-7a transcripts in pNHBEs ALI culture. Furthermore PBDEs (47, 99) (100 nM) increased Muc5AC and Muc5B mRNA, and PBDE 47 (100 nM) IL-8 mRNA via EZH2 in pNHBEs. Finally, PBDEs (100 nM) affected EZH2, H3K27me3, K-RAS protein expression, and DAB2IP, Let-7a transcripts and cell invasion in A549 cells. Gsk343 (methyltransferase EZH2 inhibitor) (1 mM) and U0126 (inhibitor of MEK1/2) (10 μM) were used to show the specific effect of PBDEs.

SIGNIFICANCE

PBDE inhalation might promote inflammation/cancer via EZH2 methyltransferase activity and H3K27me3, k-RAS and ERk1/2 involvement, generating adverse health outcomes of the human lung.

A 3D "In Vitro" Model to Study Hyaluronan Effect in Nasal Epithelial Cell Line Exposed to Double-Stranded RNA Poly(I:C)

Environmental agents, including viral and bacterial infectious agents, are involved in the alteration of physicochemical and biological parameters in the nasal epithelium. Hyaluronan (HA) has an important role in the regulation of tissue healing properties. High molecular weight HA (HMW-HA) shows greater anti-inflammatory responses than medium molecular weight HA (MMW-HA) and low molecular weight HA (LMW-HA). We investigated the effect of HMW-HA, MMW-HA and LMW-HA on the regulation of physicochemical and biological parameters in an “in vitro” model that might mimic viral infections of the nasal epithelium. Human nasal epithelial cell line RPMI2650 was stimulated with double-stranded RNA (dsRNA) Poly(I:C) for 5 days in air-liquid-interface (ALI) culture (3D model of airway tissue). dsRNA Poly(I:C) treatment significantly decreased transepithelial electrical resistance (TEER) in the stratified nasal epithelium of RPMI2650 and increased pH values, rheological parameters (elastic G’ and viscous G’’), and Muc5AC and Muc5B production in the apical wash of ALI culture of RPMI2650 in comparison to untreated cells. RPMI2650 treated with dsRNA Poly(I:C) in the presence of HMW-HA showed lower pH values, Muc5AC and Muc5B production, and rheological parameters, as well as increased TEER values in ALI culture, compared to cells treated with Poly(I:C) alone or pretreated with LMW-HA and MMW-HA. Our 3D “in vitro” model of epithelium suggests that HMW-HA might be a coadjuvant in the pharmacological treatment of viral infections, allowing for the control of some physicochemical and biological properties affecting the epithelial barrier of the nose during infection.

Cytotoxic and genotoxic effects of the flame retardants (PBDE-47, PBDE-99 and PBDE-209) in human bronchial epithelial cells

Polybrominated diphenyl ethers (PBDEs) are widespread as flame-retardants in different types of consumer products. PBDEs present in the air or dust and their inhalation can damage human health by influencing the respiratory system. We evaluated the effects of environment relevant concentrations (0.01-1  μM) of PBDE-47, PBDE-99 and PBDE-209 on the mechanism of oxidative stress, dysregulation of cell proliferation, apoptosis, and DNA damage and repair (in term of H2AX phosphorylation ser139) in an in-vitro/ex-vivo model of bronchial epithelial cells. PBDEs (-47, -99 and -209) at the environment relevant concentrations (0.01 and 1  μM) induce oxidative stress (in term of NOX-4 expression as well as ROS and JC-1 production), activate the mechanism of DNA-damage and repair affecting Olive Tail length (comet assay) production and H2AX phosphorylation (ser139) in normal human bronchial epithelial cells. Furthermore PBDEs, although do not affect cell viability, induce cell apoptosis and single cell capacity to grow into a colony (like a cancer phenotype) in bronchial epithelial cells. Finally, PBDE-47 had a greater effect than -99 and -209. PBDE-47, -99 and -209 congeners exert cytotoxic and genotoxic effects, and play a critical role in the dysregulation of oxidative stress, damaging DNA and the related gene expression in bronchial epithelial cells. Our findings might suggest that PBDEs inhalation might have adverse effect on human health regarding pulmonary diseases in the areas of environmental pollution.

Can PBDEs affect the pathophysiologic complex of epithelium in lung diseases?

Brominated flame-retardant (BFRs) exposure promotes multiple adverse health outcomes involved in oxidative stress, inflammation, and tissues damage. We investigated BFR effects, known as polybrominated diphenyl ethers (PBDEs) (47, 99 and 209) in an air-liquid-interface (ALI) airway tissue derived from A549 cell line, and compared with ALI culture of primary human bronchial epithelial cells (pHBEC). The cells, exposed to PBDEs (47, 99 and 209) (0.01-1 μM) for 24 h, were studied for IL-8, Muc5AC and Muc5B (mRNAs and proteins) production, as well as NOX-4 (mRNA) expression. Furthermore, we evaluated tight junction (TJ) integrity by Trans-Epithelial Electrical Resistance (TEER) measurements, and zonula occludens-1 (ZO-1) expression in the cells, and pH variations and rheological properties (elastic G', and viscous G″, moduli) in apical washes of ALI cultures. N-acetylcysteine (NAC) (10 mM) effects were tested in our experimental model of A549 cells. PBDEs (47, 99 and 209) exposure decreased TEER, ZO-1 and pH values, and increased IL-8, Muc5AC, Muc5B (mRNAs and proteins), NOX-4 (mRNA), and rheological parameters (G', G″) in ALI cultures of A549 cell line and pHBEC. NAC inhibited PBDE effects in A549 cells. PBDE inhalation might impairs human health of the lungs inducing oxidative stress, inflammatory response, loss of barrier integrity, unchecked mucus production, as well as altered physicochemical and biological properties of the fluids in airway epithelium. The treatment with anti-oxidants restored the negative effects of PBDEs in epithelial cells.

Cigarette smoke affects the onco-suppressor DAB2IP expression in bronchial epithelial cells of COPD patients

Cigarette smoke is a risk factor for COPD and lung cancer. In cancer, epigenetic modifications affect the expression of Enhancer of Zester Homolog 2 (EZH2), and silenced disabled homolog 2 interacting protein gene (DAB2IP) (onco-suppressor gene) by Histone H3 tri-methylation in lysine 27 (H3K27me3). In"ex vivo"studies, we assessed EZH2, H3K27me3 and DAB2IP immunoreactivity in bronchial epithelial cells from COPD patients (smokers, ex-smokers), Smoker and control subjects. In"in vitro" experiments we studied the effect of cigarette smoke extract (CSE) on EZH2/H3K27me3/DAB2IP expression, apoptosis, invasiveness, and vimentin expression in 16HBE, primary cells, and lung cancer cell lines (A549) long-term exposed to CSE. Finally, in "in vitro"studies, we tested the effect of GSK343 (selective inhibitor of EZH2). EZH2 and H3K27me3 expression was higher, while DAB2IP was lower levels, in bronchial epithelium from COPD and Smokers than in Controls. CSE increased EZH2, H3K27me3 expression and decreased DAB2IP, cell apoptosis and invasiveness in epithelial cells. GSK343 restored the effects of CSE. Cigarette smoke affects EZH2 expression, and reduced DAB2IP via H3K27me3 in COPD patients. The molecular mechanisms associated with EZH2 expression, generate a dysregulation of cell apoptosis, mesenchymal transition, and cell invasiveness in bronchial epithelial cells, encouraging the progression of airway inflammation toward lung cancer in COPD patients.

IL-17A-associated IKK-α signaling induced TSLP production in epithelial cells of COPD patients

Thymic stromal lymphopoietin (TSLP) is a cytokine expressed in the epithelium, involved in the pathogenesis of chronic disease. IL-17A regulates airway inflammation, oxidative stress, and reduction of steroid sensitivity in chronic obstructive pulmonary disease (COPD). TSLP and IL-17A were measured in induced sputum supernatants (ISs) from healthy controls (HC), healthy smokers (HS), and COPD patients by enzyme-linked immunosorbent assay. Human bronchial epithelial cell line (16HBE) and normal bronchial epithelial cells were stimulated with rhIL-17A or ISs from COPD patients to evaluate TSLP protein and mRNA expression. The effects of the depletion of IL-17A in ISs, an anticholinergic drug, and the silencing of inhibitor kappa kinase alpha (IKKα) on TSLP production were evaluated in 16HBE cells. Coimmunoprecipitation of acetyl-histone H3(Lys14)/IKKα was evaluated in 16HBE cells treated with rhIL-17A and in the presence of the drug. TSLP and IL-17A levels were higher in ISs from COPD patients and HS compared with HC. TSLP protein and mRNA increased in 16HBE cells and in normal bronchial epithelial cells stimulated with ISs from COPD patients compared with ISs from HC and untreated cells. IKKα silencing reduced TSLP production in 16HBE cells stimulated with rhIL-17A and ISs from COPD patients. RhIL-17A increased the IKKα/acetyl-histone H3 immunoprecipitation in 16HBE cells. The anticholinergic drug affects TSLP protein and mRNA levels in bronchial epithelial cells treated with rhIL-17A or with ISs from COPD patients, and IKKα mediated acetyl-histone H3(Lys14). IL-17A/IKKα signaling induced the mechanism of chromatin remodeling associated with acetyl-histone H3(Lys14) and TSLP production in bronchial epithelial cells. Anticholinergic drugs might target TSLP derived from epithelial cells during the treatment of COPD.

Cigarette smoke and non-neuronal cholinergic system in the airway epithelium of COPD patients

Acetylcholine (ACh), synthesized by Choline Acetyl-Transferase (ChAT), exerts its physiological effects via mAChRM3 in epithelial cells. We hypothesized that cigarette smoke affects ChAT, ACh, and mAChRM3 expression in the airways from COPD patients promoting airway disease. ChAT, ACh, and mAChRM3 were assessed: "ex vivo" in the epithelium from central and distal airways of COPD patients, Healthy Smoker (S) and Healthy Subjects (C), and "in vitro" in bronchial epithelial cells stimulated with cigarette smoke extract (CSE). In central airways, mAChRM3, ChAT, and ACh immunoreactivity was significantly higher in the epithelium from S and COPD than in C subjects. mAChRM3, ChAT, and ACh score of immunoreactivity was high in the metaplastia area of COPD patients. mAChRM3/ChAT and ACh/ChAT co-localization of immunoreactivity was observed in the bronchial epithelium from COPD. In vitro, CSE stimulation significantly increased mAChRM3, ChAT, and ACh expression and mAChRM3/ChAT and ACh/ChAT co-localization in 16HBE and NHBE, and increased 16HBE proliferation. Cigarette smoke modifies the levels of mAChMR3, ChAT expression, and ACh production in bronchial epithelial cells from COPD patients. Non-neuronal components of cholinergic system may have a role in the mechanism of bronchial epithelial cell proliferation, promoting alteration of normal tissue, and of related pulmonary functions.

Crosstalk between mAChRM3 and β2AR, via acetylcholine PI3/PKC/PBEP1/Raf-1 MEK1/2/ERK1/2 pathway activation, in human bronchial epithelial cells after long-term cigarette smoke exposure

BACKGROUND

Cigarette smoke extract (CSE) affects the expression of non-neuronal components of cholinergic system in bronchial epithelial cells and, as PEBP1/Raf-mediated MAPK1/2 and ERK1/2 pathway, promotes inflammation and oxidative stress.

AIMS

We studied whether Acetylcholine (ACh) is involved in the mechanism of crosstalk between mAChRM3 and β2Adrenergic receptors (β2AR) promoting, via PI3/PKC/PBEP1/Raf/MEK1/2/ERK1/2 activation, β2AR desensitization, inflammation and, oxidative stress in a bronchial epithelial cell line (16HBE) after long-term exposure to cigarette smoke extract (LECSE).

METHODS

We evaluated mAChRM3 and Choline Acetyltransferase (ChAT) expression, ACh production, PEBP1, ERk1/2, and β2AR phosphorylation, as well as NOX-4, ROS production and IL-8 release in 16HBE after LECSE. The inhibitory activity of Hemicholinium (HCh-3) (a potent choline uptake blocker), LY294002 (a highly selective inhibitor of PI3 kinase), Tiotropium (Spiriva®) (anticholinergic drug) and Olodaterol (β2AR agonist), were tested in 16HBE after LECSE.

RESULTS

mAChRM3, ChAT, ACh activity, pPEBP1, pβ2AR, pERK1/2, ROS, NOX-4 and IL-8 increased after LECSE in 16HBE LECSE compared to untreated cells. HCh-3 and LY294002 (alone or in combination) as well as Tiotropium (Spiriva®) or Olodaterol (alone or in combination) all reduced the levels of pPEBP1, pβ2AR, pERK1/2, ROS, NOX-4, and IL-8 in 16HBE LECSE compared to untreated cells.

CONCLUSIONS

LECSE promotes ACh production which enhances PI3/PKC/PEBP1/Raf-ERK1/2 pathway activation, heterologous β2AR desensitization, as well as release of inflammatory and oxidative mediators in bronchial epithelial cells. The use of anticholinergic drugs and long-acting β2-agonists, alone or in combination may be dampen these inflammatory mechanisms when used in combination in some epithelial cell types.

Identification of IL-17F/frequent exacerbator endotype in asthma

BACKGROUND

Severe asthma might be associated with overexpression of T_h17 cytokines, which induce neutrophil recruitment via neutrophil-mobilizing cytokines in airways.

OBJECTIVE

To study IL-17-related cytokines in nasal/bronchial biopsies from controls and mild asthmatics (MAs) to severe asthmatics (SAs) in relation to exacerbation rate.

METHODS

Inflammatory cells and IL-17A⁺, IL-17F⁺, IL-21⁺, IL-22⁺, and IL-23⁺ cells were examined by immunohistochemistry in cryostat sections of bronchial/nasal biopsies obtained from 33 SAs (21 frequent exacerbators [FEs]), 31 MAs (3 FEs), and 14 controls. IL-17F protein was also measured by ELISA in bronchial/nasal lysates and by immunohistochemistry in bronchial tissue obtained from subjects who died because of fatal asthma. Immunofluorescence/confocal microscopy was used for IL-17F colocalization.

RESULTS

Higher number (P < .05) of neutrophils, IL-17A⁺, IL-17F⁺, and IL-21⁺ cells in bronchial biopsies and higher numbers (P < .01) of IL-17F⁺ and IL-21⁺ cells in nasal biopsies were observed in SAs compared with MAs. Bronchial IL-17F⁺ cells correlated with bronchial neutrophils (r = 0.54), exacerbation rate (r = 0.41), and FEV₁ (r = -0.46). Nasal IL-17F⁺ cells correlated with bronchial IL-17F (r = 0.35), exacerbation rate (r = 0.47), and FEV₁ (r = -0.61). FEs showed increased number of bronchial neutrophils/eosinophils/CD4⁺/CD8⁺ cells and bronchial/nasal IL-17F⁺ cells. Receiver operating characteristic curve analysis evidenced predictive cutoff values of bronchial neutrophils and nasal/bronchial IL-17F for discriminating between asthmatics and controls, between MAs and SAs and between FEs and non-FEs. IL-17F protein increased in bronchial/nasal lysates of SAs and FEs and in bronchial tissue of fatal asthma. IL-17F colocalized in CD4⁺/CD8⁺ cells.

CONCLUSIONS

IL-17-related cytokines expression was amplified in bronchial/nasal mucosa of neutrophilic asthma prone to exacerbation, suggesting a pathogenic role of IL-17F in FEs.

Airway lipoxin A4/formyl peptide receptor 2-lipoxin receptor levels in pediatric patients with severe asthma

BACKGROUND

Lipoxins are biologically active eicosanoids with anti-inflammatory properties. Lipoxin A4 (LXA4) signaling blocks asthmatic responses in human and experimental model systems. There is evidence that patients with respiratory diseases, including severe asthma (SA), display defective generation of lipoxin signals despite glucocorticoid therapy.

OBJECTIVE

We investigated airway levels of formyl peptide receptor 2-lipoxin receptor (FPR2/ALXR), LXA4, and its counterregulatory compound, leukotriene B4 (LTB4), in patients with childhood asthma. We addressed the potential interplay of the LXA4-FPR2/ALXR axis and glucocorticoids in the resolution of inflammation.

METHODS

We examined LXA4 and LTB4 concentrations in induced sputum supernatants from children with intermittent asthma (IA), children with SA, and healthy control (HC) children. In addition, we investigated FPR2/ALXR expression in induced sputum cells obtained from the study groups. Finally, we evaluated in vitro the molecular interaction between LXA4 and glucocorticoid receptor-based mechanisms.

RESULTS

We found that children with SA have decreased LXA4 concentrations in induced sputum supernatants in comparison with children with IA. In contrast to decreases in LXA4 concentrations, LTB4 concentrations were increased in children with asthma independent of severity. LXA4 concentrations negatively correlated with LTB4 concentrations and with exacerbation numbers in children with SA. FPR2/ALXR expression was reduced in induced sputum cells of children with SA compared with that seen in HC subjects and children with IA. Finally, we describe in vitro the existence of crosstalk between LXA4 and glucocorticoid receptor at the cytosolic level mediated by G protein-coupled FPR2/ALXR in peripheral blood granulocytes isolated from HC subjects, children with IA, and children with SA.

CONCLUSION

Our findings provide evidence for defective LXA4 generation and FPR2/ALXR expression that, associated with increased LTB4, might be involved in a reduction in the ability of inhaled corticosteroids to impair control of airway inflammation in children with SA.

Prostaglandin E₂ possesses different potencies in inducing Vascular Endothelial Growth Factor and Interleukin-8 production in COPD human lung fibroblasts

We studied the role of PGE2, its biosynthetic enzymes and its receptors, in regulating the functions of lung fibroblasts through the production of Vascular Endothelial Growth Factor (VEGF) and Interleukin-8 (IL-8) in COPD subjects. Lung fibroblasts from Control (C) (n=6), Smoker (HS) (n=6) and COPD patients (n=8) were cultured, and basal PGE2, VEGF, and IL-8 measured in supernatants by ELISA. COX-1/COX-2 and EP receptors expression were assessed by western blot and by RT-PCR. Release of VEGF and IL-8 by human fetal lung fibroblasts (HFL-1; lung, diploid, human) was evaluated under different conditions. PGE2, VEGF, and IL-8 levels, COX-2, EP2, and EP4 protein expression and mRNA were increased in COPD when compared to Controls. Low concentrations of synthetic PGE2 increased the release of VEGF in HFL-1, but higher concentrations were needed to induce the release of IL-8. This effect was mimicked by an EP2 agonist and modulated by an EP4 antagonist. In the airways of COPD subjects, fibroblast-derived PGE2 may regulate angiogenesis and inflammation through the production of VEGF and IL-8 respectively, suggesting that the increase in expression of COX-2, EP2 and EP4 observed in COPD fibroblasts may contribute to steering the role of PGE2 from homeostatic to pro-inflammatory.

Advances in asthma pathophysiology: stepping forward from the Maurizio Vignola experience

Maurizio Vignola was a superb and innovative researcher, who wrote seminal papers on the biology of airway epithelium in asthma. Inflammation and remodelling were the main topics of his research, mostly conducted in biopsy specimens from patients with asthma of variable severity, encompassing the entire spectrum of the disease from mild to severe asthma. His observations contributed to define the biology of asthma as we know it today, and opened the way to the personalised treatment of asthma. His group has successfully continued to investigate the biology and clinical aspects of bronchial asthma, with major interest in the clinical use of biomarkers to monitor disease activity, and in the development of new therapeutic perspectives. This review summarises the latest work on these topics proudly conducted by Maurizio's closest collaborators. The results indicate significant progress in our understanding of asthma in the last 10 years, in particular increased knowledge of the complex interaction between inflammatory and remodelling pathways, improved recognition of biological and clinical asthma phenotypes, and development of new treatment strategies, especially for patients with severe corticosteroid-resistant asthma.

Biomarkers may help to define disease phenotypes and new treatment strategies for asthmahttp://ow.ly/G2Fl6

Cigarette smoke affects IL-17A, IL-17F and IL-17 receptor expression in the lung tissue: Ex vivo and in vitro studies

Cigarette smoke is a risk factor for Chronic Obstructive Pulmonary Disease (COPD). Th-17 cytokines are involved in the pathogenesis of COPD. We aimed to evaluate the role of cigarette smoke on the expression of IL-17A, IL-17F and IL-17R in airways of COPD patients. Epithelial and subepithelial immunoreactivity for IL-17A, IL-17F and IL-17R was assessed in surgical specimens from COPD patients (n=15) and from healthy subjects (HC) (n=10) by immunohistochemistry. In vitro, human epithelial cell line 16HBE and A549 as well as PBMC from normal donors were stimulated with cigarette smoke extract (CSE) (0%, 2.5%, 5%, 10%) to evaluate the IL-17A, IL-17F and IL-17R expression by flow cytometry. Furthermore, rhIL-17A and CSE stimulation was evaluated on proliferation and apoptosis in 16HBE and in A549. In central and distal airways immunoreactivity for IL-17A, IL-17F and IL-17R significantly increased in the epithelium and IL-17A in the subepithelium from COPD than in HC. In distal airway, immunoreactivity for IL-17F increased in the subepithelium of COPD than in HC. IL-17A immunoreactivity positively correlate with IL-17R and total pack years in the epithelium from central and distal airways of COPD patients. In vitro, CSE stimulation significantly increased IL-17F and IL-17R in 16HBE (2.5%) and A549 (5%) while IL-17A and IL-17F in PBMC (10%). IL-17A and CSE stimulation, rather than CSE or rhIL-17A alone, significantly increased proliferation in 16HBE and apoptosis in A549. Cigarette smoke increases Th17 immunity in lung tissue of COPD patients, promoting the mechanism of proliferation and apoptosis in airway epithelial cells.

IL-33/ST2 axis controls Th2/IL-31 and Th17 immune response in allergic airway diseases

IL-33 targeting ST2 receptor (T1/ST2), expressed on Th2 cell surface, regulates the production of cytokines like IL-17A and IL-31. We studied the role of IL-33/ST2 axis in IL-31 and IL-17A production in patients with allergic rhinitis (AR) and with concomitant allergic asthma and rhinitis (AAR). 20 healthy control subjects (HC), 14 AR and 17 AAR subjects were recruited and blood samples collected. IL-33, soluble ST2 (sST2), IL-17A and IL-31 plasma concentrations were measured by ELISA method. T1/ST2, IL-31 and IL-17A cellular expression were studied in peripheral blood mononuclear cells (PBMC) from HC, AR and AAR (n=6 for each group) by flow-cytometry. In vitro, we also evaluated the effect of beclomethasone dipropionate (BDP) on T1/ST2, IL-31 and IL-17A expression in CD3(+)T-cells from PBMC of AAR (n=6). Plasma levels of IL-33, IL-31 and IL-17A were significantly higher and sST2 was lower in patients with AR and AAR than in HC. IL-31 and IL-17A intracellular levels significantly increased, whereas T1/ST2 expression was significantly lower, in CD3(+)T-cells from AR and AAR compared to HC. Positive correlations were observed between plasmatic components of IL-33/ST2 axis and IL-31 in both AR and AAR and IL-17A in AAR. In vitro IL-31 and IL-17A intracellular levels decreased after BDP treatment, whereas T1/ST2 expression increased in cultured CD3(+)T-cells obtained from AAR. IL-33/ST2 axis is involved in Th2/IL-31 and Th17 immune response during the progression of allergic airway disease. In vitro BDP is able to control Th2/IL-31 and Th17 immune response in PBMC from allergic patients.

Nasal IL-17F is related to bronchial IL-17F/neutrophilia and exacerbations in stable atopic severe asthma

Severe asthma (SA) is associated with neutrophil recruitment and T helper (TH )17 chemokine overexpression in bronchial biopsies. We aimed to evaluate IL-17A and IL-17F expression in nasal/bronchial lamina propria of atopic mild-to-severe asthmatics and controls in relation to neutrophilia and asthma exacerbations. Cryostat sections of nasal/bronchial biopsies obtained from 14 SA and 14 mild asthma (MA) stable atopic patients with rhinitis, and seven healthy controls were analyzed by immunohistochemistry for neutrophils, IL-17A and IL-17F expression. Atopic SA showed an increase in asthma exacerbations number, IL-17F and IL-17A expression in nasal/bronchial lamina propria compared to MA and controls, and a higher expression of bronchial neutrophils in SA compared to MA and controls. In all asthmatics, significant relationships were found between bronchial IL-17F and neutrophils/FEV1 , nasal IL-17F and bronchial neutrophil/IL-17 markers and between the latter and exacerbations, suggesting that nasal IL-17F might be informative on bronchial IL17-driven neutrophilia in atopic SA.

Cigarette smoke alters non-neuronal cholinergic system components inducing MUC5AC production in the H292 cell line

Cigarette smoke extract (CSE) affects the expression of Choline Acetyl-Transferase (ChAT), muscarinic acetylcholine receptors, and mucin production in bronchial epithelial cells. Mucin 5AC (MUC5AC), muscarinic acetylcholine receptor M3, ChAT expression, acetylcholine levels and acetylcholine binding were measured in a human pulmonary mucoepidermoid carcinoma cell line (H292) stimulated with CSE. We performed ChAT/RNA interference experiments in H292 cells stimulated with CSE to study the role of ChAT/acetylcholine in MUC5AC production. The effects of Hemicholinium-3 (HCh-3) (50 μM) (a potent and selective choline uptake blocker) and Tiotropium bromide (Spiriva(®)) (100 nM), alone or in combination with Salmeterol (SL) and Fluticasone propionate (FP), were tested in this model. MUC5AC, muscarinic acetylcholine receptor M3, ChAT, acetylcholine expression and acetylcholine binding significantly increased in H292 cells stimulated with CSE (5%) compared to untreated cells. HCh-3 reduced acetylcholine binding and MUC5AC production in H292 cells stimulated with CSE. ChAT/RNA interference eliminated the effect of CSE on MUC5AC production. FP reduced ChAT and acetylcholine binding in unstimulated cells, while showing a partial effect in CSE stimulated cells. SL increased the ChAT expression and acetylcholine binding in H292 cells stimulated with or without CSE. Tiotropium, alone or together with FP and SL, reduced acetylcholine binding and MUC5AC production in H292 cells stimulated with CSE. CSE affects the ChAT/acetylcholine expression, increasing MUC5AC production in H292 cells. Pharmacological treatment with anticholinergic drugs reduces the secretion of MUC5AC generated by autocrine acetylcholine activity in airway epithelial cells.

IL-33/IL-31 axis: a new pathological mechanisms for EGFR tyrosine kinase inhibitors-associated skin toxicity

The dermatologic side effects are the most common adverse effects associated with Epidermal Growth Factor Receptor tyrosine kinase inhibitors. Although the mechanisms underlying the development of the skin toxicity remain unclear, immunological mechanisms are considered to be involved. A possible correlation between plasma levels of certain cytokines and development of skin toxicity has been reported. The aim of this work was to investigate the possible contribution of IL-31 and IL-33, cytokines involved in disorders associated with itching, in the pathogenesis of pruritus in patients undergoing EGFR-TK inhibitors. We report a significant increase of IL-31 and IL-33 serum levels in a patient with a bronchioalveolar carcinoma, who had showed previous skin rash, xerosis, and pruritus during treatment with different EGFR-TK inhibitors. She developed intense iching during gefitinib therapy. Therefore, we had collected patient blood sample to evaluate IL-31 and IL-33 serum levels compared to controls, reporting a significant increase in serum of patient. In the light of these findings, EGFR-TK inhibitors-related symptoms of dermatologic toxicities might be related to the release of IL-31 and IL-33. In particular, it is supposable that EGFR-TK inhibitors could cause keratinocytes injury, the release of IL-33 and the consequent interaction with its receptor on mast cells, that induces the secretion of several factors capable to cause skin manifestations, included IL-31, a known pruritus-inducing cytokine. This report, to the best of our knowledge, is the first work describing a possible involvement of IL-31/IL-33 axis in the pathogenesis of skin side effects related to EGFR-TK inhibitors treatment.

Increased levels of Th17 cells are associated with non-neuronal acetylcholine in COPD patients

T-lymphocytes, including Th17-cells and T-cells expressing acetylcholine (ACh), are key components of systemic inflammation in chronic obstructive pulmonary disease (COPD). We investigated whether ACh promotes Th17 cells in COPD. ACh, IL-17A, IL-22, RORγt, FOXP3 expression and AChIL-17A, AChIL-22, AChRORγt coexpression was evaluated in peripheral blood mononuclear cells (PBMC) from COPD patients (n=16), healthy smokers (HS) (n=12) and healthy control subjects (HC) (n=13) (cultured for 48 h with PMA) by flow cytometry. Furthermore, we studied the effect of Tiotropium (Spiriva®) (100 nM) and Olodaterol (1nM) alone or in combination, and of hemicholinium-3 (50 μM) on AChIL-17A, AChIL-22, AChRORγt, and FOXP3 expression in CD3+PBT-cells of PBMC from COPD patients (n=6) cultured for 48 h with PMA. CD3+PBT-cells expressing ACh, IL-17A, IL-22 and RORγt together with CD3+PBT-cells co-expressing AChIL-17A, AChIL-22 and AChRORγt were significantly increased in COPD patients compared to HC and HS subjects with higher levels in HS than in HC without a significant difference. CD3+FOXP3+PBT-cells were increased in HS than in HC and COPD. Tiotropium and Olodaterol reduced the percentage of CD3+PBT-cells co-expressing AChIL-17A, AChIL-22, and AChRORγt while increased the CD3+FOXP3+PBT-cells in PBMC from COPD patients, cultured in vitro for 48 h, with an additive effect when used in combination. Hemicholnium-3 reduced the percentage of ACh+IL-17A+, ACh+IL-22+, and ACh+RORγt+ while it did not affect FOXP3+ expression in CD3+PBT-cells from cultured PBMC from COPD patients. We concluded that ACh might promote the increased levels of Th17-cells in systemic inflammation of COPD. Long-acting β2-agonists and anticholinergic drugs might contribute to control this event.

The role of transforming growth factor-β1 in airway inflammation of childhood asthma

TGF-beta-targeting structural and inflammatory cells has been implicated in the mechanisms leading to the inflammatory and restructuring processes in asthma, suggesting an impact of TGF-beta1 signaling on the development and persistency of this disease. We investigated the potential early involvement of TGF-beta1 activity in the immunological and molecular mechanisms underlying progression of inflammation in childhood asthma. We evaluated the levels of TGF-beta1 in induced sputum supernatants (ISSs) and the expression of small mother cell against decapentaplegic (Smad) 2 and Smad7 proteins in induced sputum cells (ISCs) from children with intermittent asthma (IA), moderate asthma (MA) and control subjects (C). Furthermore, we investigated the regulatory role of TGF-beta1 activity on eosinophil and neutrophil adhesion to epithelial cells using adhesion assay, and on the granulocyte expression of adhesion molecule CD11b/CD18 Macrophage-1 antigen (MAC-1), by flow cytometry. We found that the levels of TGF-beta1 are increased in ISSs of IA and MA in comparison to C, concomitantly to the activation of intracellular signaling TGFbeta/Smads pathway in ISCs. In MA, TGF-beta1 levels correlated with the number of sputum eosinophils and neutrophils. Furthermore, we showed the ability of sputum TGF-beta1 to promote eosinophil and neutrophil adhesion to epithelial cells, and to increase the expression of MAC-1 on the granulocyte surface. This study shows the activation of TGFbeta/Smad signaling pathway in the airways of children with IA and, despite the regular ICS treatment, in children with MA, and provides evidence for the contribution of TGF-beta1 in the regulation of granulocyte activation and trafficking.

Gemcitabine sensitizes lung cancer cells to Fas/FasL system-mediated killing

Gemcitabine is a chemotherapy agent commonly used in the treatment of non-small cell lung cancer (NSCLC) that has been demonstrated to induce apoptosis in NSCLC cells by increasing functionally active Fas expression. The aim of this study was to evaluate the Fas/Fas ligand (FasL) system involvement in gemcitabine-induced lung cancer cell killing. NSCLC H292 cells were cultured in the presence or absence of gemcitabine. FasL mRNA and protein were evaluated by real-time PCR, and by Western blot and flow cytometry, respectively. Apoptosis of FasL-expressing cells was evaluated by flow cytometry, and caspase-8 and caspase-3 activation by Western blot and a colorimetric assay. Cytotoxicity of lymphokine-activated killer (LAK) cells and malignant pleural fluid lymphocytes against H292 cells was analysed in the presence or absence of the neutralizing anti-Fas ZB4 antibody, by flow cytometry. Gemcitabine increased FasL mRNA and total protein expression, the percentage of H292 cells bearing membrane-bound FasL (mFasL) and of mFasL-positive apoptotic H292 cells, as well as caspase-8 and caspase-3 cleavage. Moreover, gemcitabine increased CH11-induced caspase-8 and caspase-3 cleavage and proteolytic activity. Cytotoxicity of LAK cells and pleural fluid lymphocytes was increased against gemcitabine-treated H292 cells and was partially inhibited by ZB4 antibody. These results demonstrate that gemcitabine: (i) induces up-regulation of FasL in lung cancer cells triggering cell apoptosis via an autocrine/paracrine loop; (ii) induces a Fas-dependent apoptosis mediated by caspase-8 and caspase-3 activation; (iii) enhances the sensitivity of lung cancer cells to cytotoxic activity of LAK cells and malignant pleural fluid lymphocytes, partially via Fas/FasL pathway. Our data strongly suggest an active involvement of the Fas/FasL system in gemcitabine-induced lung cancer cell killing.

Plasma leptin and vascular endothelial growth factor (VEGF) in normal subjects at high altitude (5050 m)

CONTEXT

High altitude (HA) is a model of severe hypoxia exposure in humans. We hypothesized that nocturnal hypoxemia or acute maximal exercise at HA might affect plasma leptin and VEGF levels.

OBJECTIVES

Plasma leptin, VEGF and other metabolic variables were studied after nocturnal pulse oximetry and after maximal exercise in healthy lowlanders on the 3rd-4th day of stay in Lobuche (5050 m, HA) and after return to sea level (SL).

RESULTS

Leptin was similar at SL or HA in both pre- and post-exercise conditions. Pre-exercise VEGF at HA was lower, and cortisol was higher, than at SL, suggesting that nocturnal intermittent hypoxia associated with periodic breathing at HA might affect these variables.

CONCLUSIONS

Leptin levels appear unaffected at HA, whereas nocturnal hypoxic stress may affect plasma VEGF. Future HA studies should investigate the possible role of nocturnal intermittent hypoxemia on metabolism.

Effect of nebulized beclomethasone on airway inflammation and clinical status of children with allergic asthma and rhinitis: a randomized, double-blind, placebo-controlled study

We aimed to evaluate the therapeutic effect of nebulized beclomethasone dipropionate (nBDP) on both allergic asthma and rhinitis. In a randomized, double-blind, placebo-controlled study, 40 children (mean age 10.7 ± 2.1 years) with allergic asthma and rhinitis received either nBDP (daily dose of 800 µg, administered twice daily) or placebo for 4 weeks (with a face mask), after a 2-week run-in period of clinical assessment. Nasal and oral fractional exhaled nitric oxide (FeNO) measurements together with pulmonary function tests, nasal and oral exhaled breath condensate (EBC) collection for pH and interleukin-5 (IL-5) measurements as well as nasal and bronchial symptom scores were obtained at baseline and after 4-week treatment. A significant improvement in oral FeNO, oral and nasal EBC IL-5 and nasal EBC pH was observed in the nBDP group when comparing the values with baseline, together with an improvement in symptom score of the visual analogue scale, nasal obstruction, sneezing, rhinorrhea, breathing difficulty, cough, wheezing and sleep disturbance (nBDP end treatment vs. baseline, Wilcoxon signed-rank test). nBDP was more effective than placebo (ANCOVA test) in improving [difference Δ = response after treatment at the last visit (active or placebo) - value at baseline] nasal pH, oral IL-5, oral FeNO, forced expiratory volume in 1 s, forced expiratory volume in 1 s/forced vital capacity, peek expiratory flow, visual analogue scale, breathing difficulty, cough, wheezing and sleep disturbance scores. No differences were observed between the nBDP and the placebo group for symptom score of rhinitis. nBDP is a useful treatment for airway inflammation and clinical status in children with concomitant allergic asthma and rhinitis.

β₂ long-acting and anticholinergic drugs control TGF-β1-mediated neutrophilic inflammation in COPD

We quantified TGF-β1 and acetylcholine (ACh) concentrations in induced sputum supernatants (ISSs) from 18 healthy controls (HC), 22 healthy smokers (HS) and 21 COPDs. ISSs from HC, HS and COPD as well as rhTGF-β1 were also tested in neutrophil adhesion and in mAChR2, mAChR3 and ChAT expression experiments in human bronchial epithelial cells (16-HBE). Finally, we evaluated the effects of Olodaterol (a novel inhaled β(2)-adrenoceptor agonist) and Tiotropium Spiriva®, alone or in combination, on neutrophil adhesion and mAChRs and ChAT expression in stimulated 16-HBE. The results showed that 1) TGF-β1 and ACh concentrations are increased in ISSs from COPD in comparison to HC and HS, and TGF-β1 in HS is higher than in HC; 2) ISSs from COPD and HS caused increased neutrophil adhesion to 16-HBE when compared to ISSs from HC. The effect of ISSs from COPD was significantly reduced by TGF-β1 depletion or by the pretreatment with Olodaterol or Tiotropium alone or in combination, while the effect of ISSs from HS was significantly reduced by the pretreatment with Olodaterol alone; 3) mAChR2, mAChR3 and ChAT expression was increased in 16-HBE stimulated with ISSs from COPD and TGF-β1 depletion significantly reduced this effect on mAChR3 and ChAT expression; 4) rhTGF-β1 increased mAChR2, mAChR3 and ChAT expression in 16-HBE; 5) Olodaterol did not affect the expression of mAChRs and ChAT in 16-HBE. Our findings support the use of β₂ long-acting and anticholinergic drugs to control the bronchoconstriction and TGF-β1-mediated neutrophilic inflammation in COPD.

In vitro anticholinergic drugs affect CD8+ peripheral blood T-cells apoptosis in COPD

Novel pharmacological strategies are aimed at the resolution of systemic inflammation in COPD potentiating peripheral blood T-cell (PBT-cell) apoptosis. Although muscarinic acetylcholine receptors (mAChRs) M(3) and choline-acetyltransferase (ChAT) participate in the airway inflammation of COPD, their role in PBT-cell apoptosis remains unexplained. We evaluated in PBT-cells from COPD patients, smoker (S) and control (C) subjects: (1) apoptosis (by annexin V binding), (2) mAChR M(3) and ChAT expression, acetylcholine (ACh)-binding; (3) choline levels in serum and PBT-cells extracts. We tested the effects of Tiotropium (Spiriva(®)) and hemicholinium-3 (HCh-3) on apoptosis, NFκB pathway, caspases 3 and 8 activity and choline levels, in PBT-cells from COPD patients. We showed that: (1) apoptosis, mAChR M(3) and ChAT expression and the CD3+ and CD8+ ACh-binding are increased in PBT-cells from COPD patients when compared to C subjects, while CD4+/CD8+ ratio of ACh-binding to PBT cells was reduced in COPD; (2) choline levels are higher in serum and PBT-cells extracts from COPD patients than in S and C; (3) Tiotropium and HCh-3 reduced CD4+ and increased CD8+ apoptosis via caspases 3 and 8 activities and via IκB mediated mechanisms in COPD patients. This study suggests the involvement of non-neuronal components of cholinergic system in the regulation of PBT-cell apoptosis in COPD and demonstrates that Tiotropium regulates CD4+ and CD8+ PBT-cell apoptosis. It provides novel putative pharmacological targets for the resolution of systemic inflammation in COPD.

Cigarette smoke extract activates human bronchial epithelial cells affecting non-neuronal cholinergic system signalling in vitro

AIMS

Acetylcholine (ACh) is synthesized by Choline Acetyl-Transferase (ChAT) that exerts its physiological effects in airway epithelial cells via muscarinic receptor (MR) activation. We evaluate the effect of ACh stimulation on human bronchial epithelial cells (16-HBE) and test whether cigarette smoke extract (CSE) can modify the basal cellular response to ACh affecting the non-neuronal cholinergic system signalling.

MAIN METHODS

ACh stimulated 16-HBE were tested for ACh-binding, Leukotriene B(4) (LTB(4)) release and ERK1/2 and NFkB pathway activation. Additionally, we investigated all the aforementioned parameters as well as ChAT and MR proteins and mRNA expression and endogenous ACh production in CSE-treated 16-HBE.

KEY FINDINGS

We showed that ACh induced in 16-HBE, in a concentration-dependent manner, LTB(4) release via the activation of ERK1/2 and NFkB pathways. The addition of Tiotropium (Spiriva®), Gallamine, Telenzepine and 4-DAMP (muscarinic receptor antagonists), as well as of PD 098059 (MAPKK inhibitor) and BAY117082 (inhibitor of IkBα phosphorilation), down-regulated the ACh-induced effects. Additionally, CSE treatment of 16-HBE increased the binding of ACh, and shifted the LTB4 release from the concentration ACh 1μM to 10nM. Finally, we observed that the treatment of 16-HBE with CSE increased the expression of ChAT, M(2) and M(3) and of endogenous ACh production in 16-HBE. Tiotropium regulated the LTB4 release and ACh production in CSE treated 16-HBE.

SIGNIFICANCE

CSE increases the pro-inflammatory activity of human bronchial epithelial cells, and promotes the cellular response to lower concentrations of ACh, by affecting the expression of ChAT and MRs. Tiotropium might prevent pro-inflammatory events generated by ACh together with CSE.

Increased leptin/leptin receptor pathway affects systemic and airway inflammation in COPD former smokers

Background

Leptin, a hormone produced mainly by adipose tissue, regulates food intake and energy expenditure. It is involved in inflammatory diseases such as chronic obstructive pulmonary disease (COPD) and its deficiency is associated with increased susceptibility to the infection. The leptin receptor is expressed in the lung and in the neutrophils.

Methods

We measured the levels of leptin, tumor necrosis factor alpha (TNF-α) and soluble form of intercellular adhesion molecule-1 (sICAM-1) in sputum and plasma from 27 smoker and former smoker patients with stable COPD using ELISA methods. Further we analyzed leptin and its receptor expression in sputum cells from 16 COPD patients using immunocytochemistry.

Results

In plasma of COPD patients, leptin was inversely correlated with TNF-α and positively correlated with the patient weight, whereas the levels of sICAM-1 were positively correlated with TNF-α. In sputum of COPD patients leptin levels were correlated with forced expiratory volume in 1 second/forced vitality capacity. Additionally, increased levels of sputum leptin and TNF-α were observed in COPD former smokers rather than smokers. Further the expression of leptin receptor in sputum neutrophils was significantly higher in COPD former smokers than in smokers, and the expression of leptin and its receptor was positively correlated in neutrophils of COPD former smokers.

Conclusion

Our findings suggest a role of leptin in the local and systemic inflammation of COPD and, taking into account the involvement of neutrophils in this inflammatory disease, describe a novel aspect of the leptin/leptin receptor pathway in the regulation of host defense after smoking cessation.

IκB kinase-driven nuclear factor-κB activation in patients with asthma and chronic obstructive pulmonary disease

BACKGROUND

Nuclear factor-κB (NF-κB) is a transcriptional factor of different inflammatory patterns involved in asthma and chronic obstructive pulmonary disease (COPD) that is tightly controlled by IκB kinase (IKK) complex.

OBJECTIVE

We investigated the dysregulation of IKK-driven NF-κB activation in patients with asthma and COPD.

METHODS

We assessed IKKα and IKKβ expression and activation, their regulation by glucocorticosteroids, and their involvement in IL-8 synthesis in PBMCs isolated from asthmatic patients, healthy smokers (HSs), patients with COPD, and control subjects. PBMCs from control subjects were stimulated with TNF-α and cigarette smoke extract in the presence or absence of fluticasone propionate (FP), L-glutathione reduced, or both, and IKK activation and IL-8 release were evaluated.

RESULTS

IKKα activity was higher in patients with COPD and HSs than in asthmatic patients and control subjects. IKKβ activity was higher in asthmatic patients, HSs, and patients with COPD than in control subjects. In vitro FP treatment induced inhibition of both IKKα and IKKβ activity in PBMCs from asthmatic patients, patients with COPD, and HSs, although IKKβ activity was more sensitive to FP than that of IKKα. FP reduced the IL-8 released from PBMCs of asthmatic patients, patients with COPD, and HSs, although IL-8 inhibition was higher in asthmatic patients than in patients with COPD and HSs. FP reduced IKKα and IKKβ activities in TNF-α and cigarette smoke extract-treated PBMCs, with higher levels of inhibition for IKKβ than IKKα activity. L-glutathione reduced improved the downregulatory effects of FP on IKKα and IL-8 levels.

CONCLUSION

Based on differential activation of IKKα and IKKβ, our findings suggest a different profile in the upstream regulation of the IKK-driven NF-κB system in asthmatic patients and patients with COPD. These differences in the regulation of the inflammatory process may explain, at least in part, the different pharmacologic responses in these patients.

Novel perspectives in the detection of oral and nasal oxidative stress and inflammation in pediatric united airway diseases

United airway disease (UAD) concept proposed that asthma and rhinitis are both different clinical manifestation of a single inflammatory process. The aim of this study is to assess in upper and lower airways the level of inflammation and oxidative stress and to investigate the relationship between biomarkers in persistent allergic rhinitis (PER) and in concomitant asthma with PER. By a crosssectional study we measured oral and nasal (FENO) and oral and nasal EBC 8-isoprostane, LTB4 and PGE2 in children with PER (n=14) and with PER and concomitant intermittent asthma (IA; n=25), mild persistent asthma (mA; n=28), moderate persistent asthma (MA; n=13) and in Healthy Controls (HCs; n=13). Oral and nasal FENO concentrations were increased in children with PER, IA, mA and MA when compared with HCs. Nasal 8-isoprostane was higher in EBC of children with PER and asthma than in HCs. Oral and nasal LTB4 were higher in EBC of children with PER and mA than in HCs. Oral and nasal PGE2 concentrations were higher in EBC of children with PER than in HCs. Positive correlations between oral and nasal biomarkers were found in IA for LTB4 and PGE2, in mA for FENO, 8-isoprostane, LTB4 and PGE2, and in MA for PGE2. No correlations were observed in children with PER and HCs. Our results suggest that non-invasive markers of inflammation and oxidative stress might be useful to study the relationships between oral and nasal compartments in allergic children with PER and concomitant asthma with the aim of defining the UAD.

Bronchial epithelial damage after a half-marathon in nonasthmatic amateur runners

High neutrophil counts in induced sputum have been found in nonasthmatic amateur runners at rest and after a marathon, but the pathogenesis of airway neutrophilia in athletes is still poorly understood. Bronchial epithelial damage may occur during intense exercise, as suggested by investigations conducted in endurance-trained mice and competitive human athletes studied under resting conditions. To gain further information on airway changes acutely induced by exercise, airway cell composition, apoptosis, IL-8 concentration in induced sputum, and serum CC-16 level were measured in 15 male amateur runners at rest (baseline) and shortly after a half-marathon. Different from results obtained after a marathon, neutrophil absolute counts were unchanged, whereas bronchial epithelial cell absolute counts and their apoptosis increased significantly ( P < 0.01). IL-8 in induced sputum supernatants almost doubled postrace compared with baseline ( P < 0.01) and correlated positively with bronchial epithelial cell absolute counts ( R2 = 0.373, P < 0.01). Serum CC-16 significantly increased after all races ( P < 0.01). These data show mild bronchial epithelial cell injury acutely induced by intense endurance exercise in humans, extending to large airways the data obtained in peripheral airways of endurance-trained mice. Therefore, neutrophil influx into the airways of athletes may be secondary to bronchial epithelial damage associated with intense exercise.

Non-invasive markers of airway inflammation and remodeling in childhood asthma

To evaluate the relationship between pro-inflammatory and pro-remodeling mediators and severity and control of asthma in children, the levels of IL-8, MMP-9, TIMP-1 in induced sputum supernatants, the number of sputum eosinophils, as well as FeNO, were investigated in 35 asthmatic children, 12 with intermittent (IA) and 23 with moderate asthma (MA), and 9 controls (C). The patients with asthma were followed for 1 yr and sputum was obtained twice during the follow-up. Biomarker levels were correlated with the number of exacerbations. We found that IL-8, MMP-9, TIMP-1 and the numbers of eosinophils in induced sputum, as well as FeNO, were increased in children with IA and MA in comparison to C. The ongoing inflammation was confirmed by increased nuclear p65 NF-kappaB subunit localization in sputum cells. In MA, FeNO measurements, sputum eosinophils and IL-8 levels, positively correlated with the occurrence of disease exacerbations during a 1-yr follow-up. According to FeNO, sputum eosinophils and IL-8 sputum concentrations, and the number of exacerbations, two distinct phenotypes of MA were identified. This study shows that the presence of bronchial inflammation is detectable in the airways of some IA, as well as in the airways of MA, despite the regular ICS treatment. This study also proposes the need to perform large prospective studies to confirm the importance of measuring specific biomarkers in induced sputum, concomitantly to FeNO analyses, to assess sub-clinical airway inflammation and disease control in children with asthma.

Chronic obstructive pulmonary disease and neutrophil infiltration: role of cigarette smoke and cyclooxygenase products

Cigarette smoke is the main cause of chronic obstructive pulmonary disease (COPD), where it can contribute to the observed airway inflammation. PGE(2) is produced within human airways, and both pro- and anti-inflammatory activities have been reported. We quantitated PGE(2) concentrations in induced sputum supernatants from different groups of subjects and correlated the obtained values to neutrophil infiltration as well as to the expression of cyclooxygenase-2 (COX-2). Cigarette smoke extract (CSE) was used to evaluate the effect of smoking on COX-2 and PGE(2) receptor expression as well as on PGE(2) release in neutrophils and alveolar macrophages (AM) obtained from normal donors. The effects of PGE(2) and of PGE receptor agonists and antagonists were evaluated on the adhesion of neutrophil to a human bronchial epithelial cell line (16HBE). PGE(2) levels, COX-2 expression, and neutrophil infiltration were significantly higher in normal smokers and COPD smokers (P < 0.0001) compared with controls and COPD former smokers. Induced sputum supernatant caused neutrophil adhesion to 16HBE that was significantly reduced, in COPD smokers only, by PGE(2) immunoprecipitation. In vitro experiments confirmed that CSE increased PGE(2) release and COX-2 and PGE(2) receptor expression in neutrophils and AM; PGE(2) enhanced the adhesion of neutrophils to 16HBE, and a specific E-prostanoid 4 (EP(4)) receptor antagonist blunted its effect. These results suggest that CSE promote the induction of COX-2 and contributes to the proinflammatory effects of PGE(2) in the airways of COPD subjects.

Smoke, choline acetyltransferase, muscarinic receptors, and fibroblast proliferation in chronic obstructive pulmonary disease

Acetylcholine (ACh), synthesized by choline acetyltransferase (ChAT), and muscarinic M(1), M(2), and M(3) receptors (MRs) are involved in fibroblast proliferation. We evaluated ChAT, MRs, and extracellular signal-regulated kinase (ERK) 1/2 and nuclear factor (NF) kappaB activation in lung fibroblasts from patients with chronic obstructive pulmonary disease (COPD), control smokers, and controls. Human fetal lung fibroblasts (HFL-1) stimulated with interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha, and cigarette smoke extracts (CSEs) were evaluated for ChAT and MR expression. We tested the effects of ACh on fibroblast proliferation and its ability to bind fibroblasts from patients with COPD, control smokers, controls, and HFL-1 stimulated with IL-1beta, TNF-alpha, and CSE. ChAT, M(1), and M(3) expression and ERK1/2 and NFkappaB activation were increased, whereas M(2) was reduced, in COPD and smoker subjects compared with controls. IL-1beta increased the ChAT and M(3), TNF-alpha down-regulated M(2), and CSE increased ChAT and M(3) expression while down-regulating the expression of M(2) in HFL-1 cells. ACh stimulation increased fibroblast proliferation in patients with COPD, control smokers, and controls, with higher effect in control smokers and patients with COPD and increased HFL-1 proliferation only in CSE-treated cells. The binding of ACh was higher in patients with COPD and in control smokers than in controls and in CSE-treated than in IL-1beta- and TNF-alpha-stimulated HFL-1 cells. Tiotropium (Spiriva; [1alpha,2beta,4beta,5alpha,7beta-7-hydroxydi-2-thienylacetyl)oxy]-9,9-dimethyl-3-oxa-9-azoniatrcyclo[3.3.1.0(24)], C(19)H(22) NO(4)S(2)Br.H(2)O), gallamine triethiodide (C(19)H(22)N(4)O(2)S.2HCl.H(2)O), telenzepine [4,9-d-dihydro-3-methyl-4-[(4-methyl-1piperazinyl) acetyl]-10H-thieno [3,4-b][1,5]benzodiazepine-10-one dihydrobromide, C(30)H(60)I(3)N(3)O(3)], 4-diphenylacetoxy-N-methylpiperidine, PD098059 [2-(2-amino-3methoxyphenyl)-4H-1benzopyran-4-one, C(16)H(13)NO(3)], and BAY 11-7082 [(E)-3-(4-methylphenylsulfonyl)-2-propenetrile, C(10)H(9)NO(2)C], down-regulated the ACh-induced fibroblast proliferation, promoting the MRs and ERK1/2 and NFkappaB pathways involvement in this phenomenon. These results suggest that cigarette smoke might alter the expression of ChAT and MRs, promoting airway remodeling in COPD and that anticholinergic drugs, including tiotropium, might prevent these events.