Cigarette Smoke Impairs A2A Adenosine Receptor Mediated Wound Repair through Up-regulation of Duox-1 Expression.

Cigarette smoke (CS) exposure and intrinsic factors such as the NADPH oxidases produce high levels of reactive oxygen species (ROS), ensuing inflammatory tissue injury. We previously demonstrated that CS-generated ROS, particularly hydrogen peroxide (H2O2), impaired adenosine stimulated wound repair. We hypothesized that CS exposure modulates expression of Dual oxidase 1 (Duox-1), a NADPH oxidases known to generate H2O2. To test this hypothesis, we used human bronchial epithelial cell line Nuli-1 and C57BL/6 mice. Cells were treated with 5% CS extract (CSE) for various periods of time, and mice were exposed to whole body CS for six weeks. Both CSE and CS treatment induced increased expression of Duox-1, and silencing of Doux-1 improved the rate of cell wound repair induced by CSE treatment. Nuli-1 cells pretreated with thapsigargin but not calcium ionophore exhibited increased Duox-1 mRNA expression. CSE treatment stimulated PKCα activation, which was effectively blocked by pretreatment with diphenylene iodonium, a NADPH oxidase inhibitor. Compared to control, lungs from CS-exposed mice showed a significant increase in PKCα activity and Duox-1 expression. Collectively, the data demonstrated that CS exposure upregulates expression of Duox-1 protein. This further leads to H2O2 production and PKCα activation, inhibiting A2AAR-stimulated wound repair

Chronic Ethanol Exposure: Pathogenesis of Pulmonary Disease and Dysfunction

Ethanol (EtOH) is the world’s most commonly used drug, and has been widely recognized as a risk factor for developing lung disorders. Chronic EtOH exposure affects all of the organ systems in the body and increases the risk of developing pulmonary diseases such as acute lung injury and pneumonia, while exacerbating the symptoms and resulting in increased mortality in many other lung disorders. EtOH and its metabolites inhibit the immune response of alveolar macrophages (AMs), increase airway leakage, produce damaging reactive oxygen species (ROS), and disrupt the balance of antioxidants/oxidants within the lungs. In this article, we review the role of EtOH exposure in the pathogenesis and progression of pulmonary disease

Co-Exposure to Cigarette Smoke and Alcohol Decreases Airway Epithelial Cell Cilia Beating in a Protein Kinase Cε-Dependent Manner

Alcohol use disorders are associated with increased lung infections and exacerbations of chronic lung diseases. Whereas the effects of cigarette smoke are well recognized, the interplay of smoke and alcohol in modulating lung diseases is not clear. Because innate lung defense is mechanically maintained by airway cilia action and protein kinase C (PKC)-activating agents slow ciliary beat frequency (CBF), we hypothesized that the combination of smoke and alcohol would decrease CBF in a PKC-dependent manner. Primary ciliated bronchial epithelial cells were exposed to 5% cigarette smoke extract plus100 mmol/L ethanol for up to 24 hours and assayed for CBF and PKCε. Smoke and alcohol co-exposure activated PKCε by 1 hour and decreased both CBF and total number of beating cilia by 6 hours. A specific activator of PKCε, DCP-LA, slowed CBF after maximal PKCε activation. Interestingly, activation of PKCε by smoke and alcohol was only observed in ciliated cells, not basal bronchial epithelium. In precision-cut mouse lung slices treated with smoke and alcohol, PKCε activation preceded CBF slowing. Correspondingly, increased PKCε activity and cilia slowing were only observed in mice co-exposed to smoke and alcohol, regardless of the sequence of the combination exposure. No decreases in CBF were observed in PKCε knockout mice co-exposed to smoke and alcohol. These data identify PKCε as a key regulator of cilia slowing in response to combined smoke and alcohol-induced lung injury

SEGEL: A Web Server for Visualization of Smoking Effects on Human Lung Gene Expression

<div><p>Cigarette smoking is a major cause of death worldwide resulting in over six million deaths per year. Cigarette smoke contains complex mixtures of chemicals that are harmful to nearly all organs of the human body, especially the lungs. Cigarette smoking is considered the major risk factor for many lung diseases, particularly chronic obstructive pulmonary diseases (COPD) and lung cancer. However, the underlying molecular mechanisms of smoking-induced lung injury associated with these lung diseases still remain largely unknown. Expression microarray techniques have been widely applied to detect the effects of smoking on gene expression in different human cells in the lungs. These projects have provided a lot of useful information for researchers to understand the potential molecular mechanism(s) of smoke-induced pathogenesis. However, a user-friendly web server that would allow scientists to fast query these data sets and compare the smoking effects on gene expression across different cells had not yet been established. For that reason, we have integrated eight public expression microarray data sets from trachea epithelial cells, large airway epithelial cells, small airway epithelial cells, and alveolar macrophage into an online web server called SEGEL (Smoking Effects on Gene Expression of Lung). Users can query gene expression patterns across these cells from smokers and nonsmokers by gene symbols, and find the effects of smoking on the gene expression of lungs from this web server. Sex difference in response to smoking is also shown. The relationship between the gene expression and cigarette smoking consumption were calculated and are shown in the server. The current version of SEGEL web server contains 42,400 annotated gene probe sets represented on the Affymetrix Human Genome U133 Plus 2.0 platform. SEGEL will be an invaluable resource for researchers interested in the effects of smoking on gene expression in the lungs. The server also provides useful information for drug development against smoking-related diseases. The SEGEL web server is available online at <a href="http://www.chengfeng.info/smoking_database.html" target="_blank">http://www.chengfeng.info/smoking_database.html</a>.</p></div

Influence of Cigarettes and Alcohol on the Severity and Death of COVID-19: A Multicenter Retrospective Study in Wuhan, China

Background: The recent emergence and rapid global spread of coronavirus disease 2019 (COVID-19) is leading to public health crises worldwide. Alcohol consumption and cigarette smoking (CS) are two known risk factors in many diseases including respiratory infections. Methods: We performed a multi-center study in the four largest hospitals designated for COVID-19 patients in Wuhan. There are totally 1547 patients diagnosed with COVID-19 enrolled in the study, alcohol consumption and CS history were evaluated among these patients. The epidemiology, laboratory findings and outcomes of patients contracted COVID-19 were further studied. Results: Our findings indicated that COVID-19 patients with a history of CS tend to have more severe outcomes than non-smoking patients. However, alcohol consumption did not reveal significant effects on neither development of severe illness nor death rates in COVID-19 patients. Conclusion: CS is a risk factor for developing severe illness and increasing mortality during the SARS-CoV-2 infection. We believe that our findings will provide a better understanding on the effects of alcohol intake and CS exposure in COVID-19 patients

The expression levels of the gene ADORA2B in different cell types from smokers (red bars) and nonsmokers (green bars).

<p>These cell types include small airways epithelial cells, large airways epithelial cells, trachea epithelial cells, and alveolar macrophage.</p

The ADORA2B expression level changes along with age in smokers (red) and nonsmokers (green).

<p>The ADORA2B expression level changes along with age in smokers (red) and nonsmokers (green).</p

The ratio (log2-transformed) of ADORA2B expression levels in smokers vs nonsmokers.

<p>Positive and negative values in the graph demonstrated up and down regulation of the gene in smokers. The dotted line represents 1,5 fold change.</p

NLRP3 Deletion Protects from Hyperoxia-induced Acute Lung Injury

Inspiration of a high concentration of oxygen, a therapy for acute lung injury (ALI), could unexpectedly lead to reactive oxygen species (ROS) production and hyperoxia-induced acute lung injury (HALI). Nucleotide-binding domain and leucine-rich repeat PYD-containing protein 3 (NLRP3) senses the ROS, triggering inflammasome activation and interleukin-1β (IL-1β) production and secretion. However, the role of NLRP3 inflammasome in HALI is unclear. The main aim of this study is to determine the effect of NLRP3 gene deletion on inflammatory response and lung epithelial cell death. Wild-type (WT) and NLRP3−/− mice were exposed to 100% O2 for 48–72 h. Bronchoalveolar lavage fluid and lung tissues were examined for proinflammatory cytokine production and lung inflammation. Hyperoxia-induced lung pathological score was suppressed in NLRP3−/− mice compared with WT mice. Hyperoxia-induced recruitment of inflammatory cells and elevation of IL-1β, TNFα, macrophage inflammatory protein-2, and monocyte chemoattractant protein-1 were attenuated in NLRP3−/− mice. NLRP3 deletion decreased lung epithelial cell death and caspase-3 levels and a suppressed NF-κB levels compared with WT controls. Taken together, this research demonstrates for the first time that NLRP3-deficient mice have suppressed inflammatory response and blunted lung epithelial cell apoptosis to HALI. acute lung injury (ALI) is characterized by severe alveolar damage resulting from an acute inflammatory response that leads to proinflammatory cytokine production, neutrophil, macrophage infiltration, and edema. The most severe form of ALI is acute respiratory distress syndrome (ARDS), which is a major cause for admission to critical care units. Hyperoxia therapy is a necessary part of treatment for patients with acute and chronic cardiovascular and pulmonary diseases. However, prolonged exposure to hyperoxia could deteriorate ALI (19, 47). Currently, there are several animal models available to study the mechanism of ALI. The hyperoxia-induced acute lung injury (HALI) animal model became widely used to study human ALI after Cochrane et al. (7) revealed the increase of oxidants in the lungs of patients with ARDS. It is now well established that there are clinically relevant similarities between the animal model of HALI and human lung injury (26). However, the molecular mechanisms that initiate and amplify the lung inflammation in response to inhaled oxygen are not well understood. IL-1β is one of the most potent early cytokines found in ALI patients, and it induces the production of other cytokines (12). The proinflammatory cytokine IL-1β is also known to be one of the most biologically important inflammatory mediators in the air space of patients with early ALI (35). Interestingly, IL-1β can also act as an important activator and prosurvival cytokine for neutrophils (37). However, mechanisms that initiate IL-1β processing in ALI are not clearly defined. Martinon et al. (25) first reported in 2002 that caspase-1-mediated processing of IL-1β is mediated by the nucleotide-binding domain and leucine-rich repeat PYD-containing protein 3 (NLRP3) inflammasome. The NLRP3 inflammasome is a multiprotein complex, which contains NLRP3, the caspase recruitment domain containing protein Cardinal, apoptosis-associated speck-like protein (ASC), and caspase-1 (33). NLRP3 inflammasome is implicated in sensing stress caused by reactive oxygen species (9, 32). Recently we showed that hyperoxia induces inflammasome activation (21, 22). However, whether inhibition or deletion of NLRP3 inflammasome is critical to confer protection against HALI has not been studied yet. Since the HALI model is thoroughly characterized in terms of reactive oxygen species involvement, assessing the effect of NLRP3 deletion on HALI will provide important information about how NLRP3 plays a role in HALI and might result in novel therapeutic strategies to treat ALI. In this study for the first time we used NLRP3-deficient mice to identify the role of inflammasomes in hyperoxia-induced lung injury