scholarly journals Cigarette smoke exposure and alveolar macrophages: mechanisms for lung disease

Thorax ◽  
2021 ◽  
pp. thoraxjnl-2020-216296
Author(s):  
Sebastian T Lugg ◽  
Aaron Scott ◽  
Dhruv Parekh ◽  
Babu Naidu ◽  
David R Thickett
Keyword(s):  
Cigarette Smoking ◽  
Lung Injury ◽  
Lung Disease ◽  
Alveolar Macrophage ◽  
Cigarette Smoke ◽  
Alveolar Macrophages ◽  
Iron Homeostasis ◽  
Cigarette Smoke Exposure ◽  
Bacterial Killing ◽  
Macrophage Populations

Cigarette smoking is the leading cause of preventable death worldwide. It causes chronic lung disease and predisposes individuals to acute lung injury and pulmonary infection. Alveolar macrophages are sentinel cells strategically positioned in the interface between the airway lumen and the alveolar spaces. These are the most abundant immune cells and are the first line of defence against inhaled particulates and pathogens. Recently, there has been a better understanding about the ontogeny, phenotype and function of alveolar macrophages and their role, not only in phagocytosis, but also in initiating and resolving immune response. Many of the functions of the alveolar macrophage have been shown to be dysregulated following exposure to cigarette smoke. While the mechanisms for these changes remain poorly understood, they are important in the understanding of cigarette smoking-induced lung disease. We review the mechanisms by which smoking influences alveolar macrophage: (1) recruitment, (2) phenotype, (3) immune function (bacterial killing, phagocytosis, proteinase/anti-proteinase release and reactive oxygen species production) and (4) homeostasis (surfactant/lipid processing, iron homeostasis and efferocytosis). Further understanding of the mechanisms of cigarette smoking on alveolar macrophages and other lung monocyte/macrophage populations may allow novel ways of restoring cellular function in those patients who have stopped smoking in order to reduce the risk of subsequent infection or further lung injury.

scholarly journals Cigarette Smoke Exposure Worsens Endotoxin-Induced Lung Injury and Pulmonary Edema in Mice

2017 ◽  
Vol 19 (9) ◽  
pp. 1033-1039 ◽  
Author(s):  
Jeffrey E Gotts ◽  
Jason Abbott ◽  
Xiaohui Fang ◽  
Haru Yanagisawa ◽  
Naoki Takasaka ◽  
...  
Keyword(s):  
Lung Injury ◽  
Pulmonary Edema ◽  
Cigarette Smoke ◽  
Smoke Exposure ◽  
Cigarette Smoke Exposure

scholarly journals p53- and PAI-1-mediated induction of C-X-C chemokines and CXCR2: importance in pulmonary inflammation due to cigarette smoke exposure

2016 ◽  
Vol 310 (6) ◽  
pp. L496-L506 ◽  
Author(s):  
Nivedita Tiwari ◽  
Amarnath S. Marudamuthu ◽  
Yoshikazu Tsukasaki ◽  
Mitsuo Ikebe ◽  
Jian Fu ◽  
...  
Keyword(s):  
Lung Injury ◽  
Cigarette Smoke ◽  
Lung Inflammation ◽  
Cellular Adhesion ◽  
Alveolar Epithelial Cells ◽  
Cigarette Smoke Exposure ◽  
Chronic Obstructive ◽  
P53 Expression ◽  
Cellular Adhesion Molecule ◽  
Pai 1

We previously demonstrated that tumor suppressor protein p53 augments plasminogen activator inhibitor-1 (PAI-1) expression in alveolar epithelial cells (AECs) during chronic cigarette smoke (CS) exposure-induced lung injury. Chronic lung inflammation with elevated p53 and PAI-1 expression in AECs and increased susceptibility to and exacerbation of respiratory infections are all associated with chronic obstructive pulmonary disease (COPD). We recently demonstrated that preventing p53 from binding to the endogenous PAI-1 mRNA in AECs by either suppressing p53 expression or blockading p53 interactions with the PAI-1 mRNA mitigates apoptosis and lung injury. Within this context, we now show increased expression of the C-X-C chemokines (CXCL1 and CXCL2) and their receptor CXCR2, and the intercellular cellular adhesion molecule-1 (ICAM-1), in the lung tissues of patients with COPD. We also found a similar increase in lung tissues and AECs from wild-type (WT) mice exposed to passive CS for 20 wk and in primary AECs treated with CS extract in vitro. Interestingly, passive CS exposure of mice lacking either p53 or PAI-1 expression resisted an increase in CXCL1, CXCL2, CXCR2, and ICAM-1. Furthermore, inhibition of p53-mediated induction of PAI-1 expression by treatment of WT mice exposed to passive CS with caveolin-1 scaffolding domain peptide reduced CXCL1, CXCL2, and CXCR2 levels and lung inflammation. Our study reveals that p53-mediated induction of PAI-1 expression due to chronic CS exposure exacerbates lung inflammation through elaboration of CXCL1, CXCL2, and CXCR2. We further provide evidence that targeting this pathway mitigates lung injury associated with chronic CS exposure.

Structural and functional remodeling of the female Apoe-/- mouse aorta due to chronic cigarette smoke exposure

2021 ◽  
Author(s):  
Yasmeen M. Farra ◽  
Jacqueline Matz ◽  
Bhama Ramkhelawon ◽  
Jessica M. Oakes ◽  
Chiara Bellini
Keyword(s):  
Cigarette Smoking ◽  
Cigarette Smoke ◽  
Cigarette Smoke Exposure ◽  
Wall Thickening ◽  
Cross Sectional ◽  
Fibrous Cap ◽  
Cardiovascular Morbidity And Mortality ◽  
Chronic Smoking ◽  
And Function ◽  
Thoracic And Abdominal

Despite a decline in popularity over the last several decades, cigarette smoking remains a leading cause of cardiovascular morbidity and mortality. Yet, the effects of cigarette smoking on vascular structure and function are largely unknown. To evaluate changes in the mechanical properties of the aorta that occur with chronic smoking, we exposed female Apolipoprotein E-deficient mice to mainstream cigarette smoke daily for 24 weeks, with room air as control. By the time of sacrifice, cigarette-exposed mice had lower body mass, but experienced larger systolic/diastolic blood pressure when compared to controls. Smoking was associated with significant wall thickening, reduced axial stretch, and circumferential material softening of the aorta. While this contributed to maintaining intrinsic tissue stiffness at control levels despite larger pressure loads, the structural stiffness became significantly larger. Furthermore, the aorta from cigarette-exposed mice exhibited decreased ability to store elastic energy and augment diastolic blood flow. Histological analysis revealed a region-dependent increase in the cross-sectional area due to smoking. Increased smooth muscle and extracellular matrix content led to medial thickening in the ascending aorta, while collagen deposition increased the thickness of the descending thoracic and abdominal aorta. Atherosclerotic lesions were larger in exposed vessels and featured a necrotic core overlaid by a thinned fibrous cap and macrophage infiltration, consistent with a vulnerable phenotype. Collectively, our data indicate that cigarette smoking decreases the mechanical functionality of the aorta, inflicts morphometric alterations to distinct segments of the aorta, and accelerates the progression of atherosclerosis.

scholarly journals Cigarette Smoke Exposure Inhibits Bacterial Killing via TFEB-Mediated Autophagy Impairment and Resulting Phagocytosis Defect

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Garrett Pehote ◽  
Manish Bodas ◽  
Kathryn Brucia ◽  
Neeraj Vij
Keyword(s):  
Cigarette Smoke ◽  
Therapeutic Potential ◽  
Underlying Mechanism ◽  
Cigarette Smoke Extract ◽  
Cigarette Smoke Exposure ◽  
Control Group ◽  
Bacterial Clearance ◽  
Bacterial Killing ◽  
Bactericidal Activities ◽  
Autophagy Inhibition

Introduction. Cigarette smoke (CS) exposure is the leading risk factor for COPD-emphysema pathogenesis. A common characteristic of COPD is impaired phagocytosis that causes frequent exacerbations in patients leading to increased morbidity. However, the underlying mechanism is unclear. Hence, we investigated if CS exposure causes autophagy impairment as a mechanism for diminished bacterial clearance via phagocytosis by utilizing murine macrophages (RAW264.7 cells) and Pseudomonas aeruginosa (PA01-GFP) as an experimental model. Methods. Briefly, RAW cells were treated with cigarette smoke extract (CSE), chloroquine (autophagy inhibitor), TFEB-shRNA, CFTR(inh)-172, and/or fisetin prior to bacterial infection for functional analysis. Results. Bacterial clearance of PA01-GFP was significantly impaired while its survival was promoted by CSE (p<0.01), autophagy inhibition (p<0.05; p<0.01), TFEB knockdown (p<0.01; p<0.001), and inhibition of CFTR function (p<0.001; p<0.01) in comparison to the control group(s) that was significantly recovered by autophagy-inducing antioxidant drug, fisetin, treatment (p<0.05; p<0.01; and p<0.001). Moreover, investigations into other pharmacological properties of fisetin show that it has significant mucolytic and bactericidal activities (p<0.01; p<0.001), which warrants further investigation. Conclusions. Our data suggests that CS-mediated autophagy impairment as a critical mechanism involved in the resulting phagocytic defect, as well as the therapeutic potential of autophagy-inducing drugs in restoring is CS-impaired phagocytosis.

scholarly journals Mesenchymal Stem Cells Attenuate Acute Lung Injury in Mice Partly by Suppressing Alveolar Macrophage Activation in a PGE2-dependent Manner

2021 ◽  
Author(s):  
Gaojian Wang ◽  
Yaping Zhang ◽  
Nianqiang Hu ◽  
Qinxue Liu ◽  
Fengjie Ma ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Alveolar Macrophage ◽  
Alveolar Macrophages ◽  
Macrophage Activation ◽  
Rna Seq ◽  
Ep4 Receptor ◽  
Pge2 Receptor ◽  
Cox2 Inhibitor

Abstract Background: Mesenchymal stem cell have shown therapeutic effect on acute lung injury, MSC could be activated when added to inflammatory environment and in turn suppress inflammation, yet the mechanism is complex and not understood. Methods: To determine the effect of MSC on ALI and alveolar macrophage activation, MSCs were administered to ALI mice and co-cultured with activated MH-S cells (alveolar macrophage cell line). To find the genes critical for MSC’s immunosuppressive effects, rest and activated MSCs induced by inflammatory MH-S cells were harvested for RNA-seq. To prove that PGE2 participates in the immunosuppressive effects of MSC, COX2 inhibitor and PGE2 receptor antagonist were added to the co-culture system and administrated to ALI mice. Results: The intratracheal administration of MSCs attenuated ALI and suppressed alveolar macrophages activation in vivo, the activation of MH-S cells was also significantly reduced after co-culturing with MSCs in vitro. The RNA-seq data of rest and activated MSCs suggested that the Ptgs2 gene may play an important role in MSC exerting immunosuppressive effects. Correspondingly, we found that the COX2 protein and PGE2 released by activated MSCs were increased dramatically after co-culturing with MH-S. The use of COX2 inhibitor NS-398 restrained the secretion of PGE2 and reversed the suppressive effect on macrophages activation of MSCs in vitro. Furthermore, GW627368X, a selective antagonist of PGE2 receptor (EP4 receptor), also reversed the inhibitory effects of MSCs on alveolar macrophages and their protective effects on ALI mice.Conclusions: MSC attenuate ALI partly through suppressing alveolar macrophage activation via PGE2 binding to EP4 receptor.

Smoking-Related “Interstitial” Lung Disease

2014 ◽  
Vol 139 (8) ◽  
pp. 974-977 ◽  
Author(s):  
Teri J. Franks ◽  
Jeffrey R. Galvin
Keyword(s):  
Lung Injury ◽  
Cigarette Smoke ◽  
Cigarette Smoke Exposure ◽  
Wall Thickening ◽  
Alveolar Wall ◽  
Cigarette Smokers ◽  
Pulmonary Langerhans Cell Histiocytosis ◽  
Airway Injury ◽  
Wide Range ◽  
Arteriolar Wall

Context Emphysema, respiratory bronchiolitis, desquamative interstitial pneumonia, pulmonary Langerhans' cell histiocytosis, small-airway injury including submucosal and adventitial fibrosis, increased bronchus-associated lymphoid tissue, and small artery/arteriolar wall thickening are recognized histologic findings in cigarette smokers. It has only recently been acknowledged that the range of lung injury from cigarette smoke is wider than generally accepted, in particular, there is increasing recognition that fibrosis of alveolar walls occurs in smokers. Objectives To review the literature that describes the range of histologic findings in cigarette smokers and that links cigarette smoke exposure to the development of alveolar wall fibrosis. Data Sources Relevant peer-reviewed literature indexed in PubMed (National Library of Medicine) form the basis of this review. Conclusions Smokers demonstrate a wide range of lung injury at biopsy that defies simple placement within single categories, and the current categories do not adequately take into account the importance of alveolar wall and airway fibrosis.

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