scholarly journals The Aryl Hydrocarbon Receptor Attenuates Acute Cigarette Smoke-Induced Airway Neutrophilia Independent of the Dioxin Response Element

2021 ◽  
Vol 12 ◽  
Author(s):  
Angela Rico de Souza ◽  
Hussein Traboulsi ◽  
Xinyu Wang ◽  
Jorg H. Fritz ◽  
David H. Eidelman ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Pulmonary Inflammation ◽  
Cigarette Smoke Exposure ◽  
Mouse Strains ◽  
Chronic Obstructive ◽  
Response Element ◽  
Aryl Hydrocarbon ◽  
Chronic Lung Diseases ◽  
Anti Inflammatory

Cigarette smoke is a prevalent respiratory toxicant that remains a leading cause of death worldwide. Cigarette smoke induces inflammation in the lungs and airways that contributes to the development of diseases such as lung cancer and chronic obstructive pulmonary disease (COPD). Due to the presence of aryl hydrocarbon receptor (AhR) ligands in cigarette smoke, activation of the AhR has been implicated in driving this inflammatory response. However, we have previously shown that the AhR suppresses cigarette smoke-induced pulmonary inflammation, but the mechanism by which the AhR achieves its anti-inflammatory function is unknown. In this study, we use the AhR antagonist CH-223191 to inhibit AhR activity in mice. After an acute (3-day) cigarette smoke exposure, AhR inhibition was associated with significantly enhanced neutrophilia in the airways in response to cigarette smoke, mimicking the phenotype of AhR-deficient mice. We then used genetically-modified mouse strains which express an AhR that can bind ligand but either cannot translocate to the nucleus or bind its cognate response element, to show that these features of the AhR pathway are not required for the AhR to suppress pulmonary neutrophilia. Finally, using the non-toxic endogenous AhR ligand FICZ, we provide proof-of-concept that activation of pulmonary AhR attenuates smoke-induced inflammation. Collectively, these results support the importance of AhR activity in mediating its anti-inflammatory function in response to cigarette smoke. Further investigation of the precise mechanisms by which the AhR exerts is protective functions may lead to the development of therapeutic agents to treat people with chronic lung diseases that have an inflammatory etiology, but for which few therapeutic options exist.

scholarly journals The Aryl Hydrocarbon Receptor Suppresses Chronic Smoke-Induced Pulmonary Inflammation

2021 ◽  
Vol 3 ◽  
Author(s):  
Necola Guerrina ◽  
Hussein Traboulsi ◽  
David H. Eidelman ◽  
Carolyn J. Baglole
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Therapeutic Potential ◽  
Pulmonary Inflammation ◽  
Giant Cells ◽  
Protective Role ◽  
Smoke Exposure ◽  
Cigarette Smoke Exposure ◽  
Aryl Hydrocarbon ◽  
Chronic Lung Diseases

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor expressed in the lungs that is activated by numerous xenobiotic, endogenous and dietary ligands. Although historically the AhR is known for mediating the deleterious response to the environmental pollutant dioxin, emerging evidence supports a prominent role for the AhR in numerous biological process including inflammation. We have shown that the AhR suppresses pulmonary neutrophilia in response to acute cigarette smoke exposure. Whether the AhR can also prevent lung inflammation from chronic smoke exposure is not known but highly relevant, given that people smoke for decades. Using our preclinical smoke model, we report that exposure to chronic cigarette smoke for 8-weeks or 4 months significantly increased pulmonary inflammation, the response of which was greater in Ahr−/− mice. Notably, there was an increased number of multinucleated giant cells (MNGCs) in smoke-exposed Ahr−/− mice without a change in cytokine levels. These data support a protective role for the AhR against the deleterious effects of cigarette smoke, warranting continued investigation into its therapeutic potential for chronic lung diseases.

scholarly journals Aryl hydrocarbon receptor (AhR)-dependent regulation of pulmonary miRNA by chronic cigarette smoke exposure

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Sarah Rogers ◽  
Angela Rico de Souza ◽  
Michela Zago ◽  
Matthew Iu ◽  
Necola Guerrina ◽  
...  
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Smoke Exposure ◽  
Cigarette Smoke Exposure ◽  
Aryl Hydrocarbon

scholarly journals Pneumocystis murina Infection and Cigarette Smoke Exposure Interact To Cause Increased Organism Burden, Development of Airspace Enlargement, and Pulmonary Inflammation in Mice

2008 ◽  
Vol 76 (8) ◽  
pp. 3481-3490 ◽  
Author(s):  
Paul J. Christensen ◽  
Angela M. Preston ◽  
Tony Ling ◽  
Ming Du ◽  
W. Bradley Fields ◽  
...  
Keyword(s):  
Cigarette Smoke ◽  
Pulmonary Inflammation ◽  
Airflow Obstruction ◽  
Smoke Exposure ◽  
Cigarette Smoke Exposure ◽  
Chronic Obstructive ◽  
Respiratory Pathogens ◽  
Obstructive Pulmonary Disease ◽  
Immunocompetent Mice

ABSTRACT Chronic obstructive pulmonary disease (COPD) is characterized by the presence of airflow obstruction and lung destruction with airspace enlargement. In addition to cigarette smoking, respiratory pathogens play a role in pathogenesis, but specific organisms are not always identified. Recent reports demonstrate associations between the detection of Pneumocystis jirovecii DNA in lung specimens or respiratory secretions and the presence of emphysema in COPD patients. Additionally, human immunodeficiency virus-infected individuals who smoke cigarettes develop early emphysema, but a role for P. jirovecii in pathogenesis remains speculative. We developed a new experimental model using immunocompetent mice to test the interaction of cigarette smoke exposure and environmentally acquired Pneumocystis murina infection in vivo. We hypothesized that cigarette smoke and P. murina would interact to cause increases in total lung capacity, airspace enlargement, and pulmonary inflammation. We found that exposure to cigarette smoke significantly increases the lung organism burden of P. murina. Pulmonary infection with P. murina, combined with cigarette smoke exposure, results in changes in pulmonary function and airspace enlargement characteristic of pulmonary emphysema. P. murina and cigarette smoke exposure interact to cause increased lung inflammatory cell accumulation. These findings establish a novel animal model system to explore the role of Pneumocystis species in the pathogenesis of COPD.

Interleukin-6 neutralization alleviates pulmonary inflammation in mice exposed to cigarette smoke and poly(I:C)

2013 ◽  
Vol 125 (10) ◽  
pp. 483-493 ◽  
Author(s):  
Cedric Hubeau ◽  
John E. Kubera ◽  
Katherine Masek-Hammerman ◽  
Cara M. M. Williams
Keyword(s):  
Cigarette Smoke ◽  
Interleukin 6 ◽  
Neutralizing Antibodies ◽  
Pulmonary Inflammation ◽  
Poly I:C ◽  
Cigarette Smoke Exposure ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Chemokine Ligand ◽  
Synthetic Ligand

Increased systemic and pulmonary levels of IL-6 (interleukin-6) are associated with the severity of exacerbations and decline of lung function in patients with COPD (chronic obstructive pulmonary disease). Whether IL-6 is directly involved or plays a bystander role in the pathophysiology of COPD remains unclear. Here we hypothesized that neutralizing circulating levels of IL-6 would modulate episodes of acute pulmonary inflammation following CS (cigarette smoke) exposure and virus-like challenges. For this purpose, we used a model where C57BL/6 mice were exposed to CS twice daily via a nose-only system, and concomitant periodic intranasal challenge with poly(I:C), a synthetic ligand for TLR3 (Toll-like receptor 3) that mimics the encounter with double stranded RNA that is carried by influenza-like viruses. This protocol recapitulates several aspects of acute pulmonary inflammation associated with COPD, including prominent airway neutrophilia, insensitivity to steroid treatment and increased levels of several inflammatory cytokines in BAL (bronchoalveolar lavage) samples. Although IL-6-deficient mice exposed to CS/poly(I:C) developed pulmonary inflammation similar to WT (wild-type) controls, WT mice exposed to CS/poly(I:C) and treated intraperitoneally with IL-6-neutralizing antibodies showed significantly lower blood counts of lymphocytes and monocytes, lower BAL levels of IL-6 and CXCL1 (CXC chemokine ligand 1)/KC (keratinocyte chemoattractant), as well as reduced numbers of BAL neutrophils, lymphocytes and macrophages. Our results thus indicate that the systemic neutralization of IL-6 significantly reduces CS/poly(I:C)-induced pulmonary inflammation, which may be a relevant approach to the treatment of episodes of acute pulmonary inflammation associated with COPD.

scholarly journals The Aryl Hydrocarbon Receptor and the Maintenance of Lung Health

2018 ◽  
Vol 19 (12) ◽  
pp. 3882 ◽  
Author(s):  
Necola Guerrina ◽  
Hussein Traboulsi ◽  
David Eidelman ◽  
Carolyn Baglole
Keyword(s):  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Respiratory Illness ◽  
Chronic Obstructive ◽  
Environmental Toxicants ◽  
Obstructive Pulmonary Disease ◽  
Aryl Hydrocarbon ◽  
Disease States ◽  
Physiological Processes ◽  
Lung Health

Much of what is known about the Aryl Hydrocarbon Receptor (AhR) centers on its ability to mediate the deleterious effects of the environmental toxicant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin). However, the AhR is both ubiquitously-expressed and evolutionarily-conserved, suggesting that it evolved for purposes beyond strictly mediating responses to man-made environmental toxicants. There is growing evidence that the AhR is required for the maintenance of health, as it is implicated in physiological processes such as xenobiotic metabolism, organ development and immunity. Dysregulation of AhR expression and activity is also associated with a variety of disease states, particularly those at barrier organs such as the skin, gut and lungs. The lungs are particularly vulnerable to inhaled toxicants such as cigarette smoke. However, the role of the AhR in diseases such as chronic obstructive pulmonary disease (COPD)—a respiratory illness caused predominately by cigarette smoking—and lung cancer remains largely unexplored. This review will discuss the growing body of literature that provides evidence that the AhR protects the lungs against the damaging effects of cigarette smoke.

scholarly journals Hydroquinone Exposure Worsens Rheumatoid Arthritis through the Activation of the Aryl Hydrocarbon Receptor and Interleukin-17 Pathways

Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 929
Author(s):  
Cintia Scucuglia Heluany ◽  
Paula Barbim Donate ◽  
Ayda Henriques Schneider ◽  
André Luis Fabris ◽  
Renan Augusto Gomes ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Gene Expression ◽  
Aryl Hydrocarbon Receptor ◽  
Cigarette Smoke ◽  
Cigarette Smoke Exposure ◽  
Interleukin 17 ◽  
Aryl Hydrocarbon ◽  
Tnf Α

Rheumatoid arthritis (RA) development is strongly associated with cigarette smoke exposure, which activates the aryl hydrocarbon receptor (AhR) as a trigger for Th17 inflammatory pathways. We previously demonstrated that the exposure to hydroquinone (HQ), one of the major compounds of cigarette tar, aggravates the arthritis symptomatology in rats. However, the mechanisms related to the HQ-related RA still remain elusive. Cell viability, cytokine secretion, and gene expression were measured in RA human fibroblast-like synoviocytes (RAHFLS) treated with HQ and stimulated or not with TNF-α. Antigen-induced arthritis (AIA) was also elicited in wild type (WT), AhR −/− or IL-17R −/− C57BL/6 mice upon daily exposure to nebulized HQ (25ppm) between days 15 to 21. At day 21, mice were challenged with mBSA and inflammatory parameters were assessed. The in vitro HQ treatment up-regulated TNFR1, TNFR2 expression, and increased ROS production. The co-treatment of HQ and TNF-α enhanced the IL-6 and IL-8 secretion. However, the pre-incubation of RAHFLS with an AhR antagonist inhibited the HQ-mediated cell proliferation and gene expression profile. About the in vivo approach, the HQ exposure worsened the AIA symptoms (edema, pain, cytokines secretion and NETs formation) in WT mice. These AIA effects were abolished in HQ-exposed AhR −/− and IL-17R −/− animals though. Our data demonstrated the harmful HQ influence over the onset of arthritis through the activation and proliferation of synoviocytes. The HQ-related RA severity was also associated with the activation of AhR and IL-17 pathways, highlighting how cigarette smoke compounds can contribute to the RA progression.

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.

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