Production of superoxide radicals is a central property of professional phagocytes used to combat invading microorganisms. Even though the number of macrophages and neutrophils is often increased in the lungs of patients with chronic lung diseases, these patients frequently suffer from bacterially induced exacerbations. To understand the underlying mechanisms, we investigated the production of superoxide radicals by bronchoalveolar lavage (BAL) cells in a rat NO(2) exposure model (10 ppm NO(2) for 1, 3, or 20 days). We showed that cells from NO(2)-exposed animals display a significantly impaired superoxide radical release after zymosan stimulation. The use of specific inhibitors (antimycin or diphenyleneiodonium [DPI]) revealed that the major enzyme systems, NADPH oxidase and complex III of the respiratory chain, are affected. In addition, we investigated gene expression and enzyme activities of antioxidant enzymes. mRNA expression was significantly enhanced for glutathione peroxidase (GPx)-3 and CuZn-superoxide dismutase (SOD) in BAL cells from animals exposed 3 and 20 days, and GPx and SOD enzyme activities were increased in BAL cells from rats exposed 20 days. In conclusion, concomitant occurrence of reduced production and increased scavenging of superoxide radicals resulted in the drastically impaired release of these radicals from BAL cells of NO(2)-exposed rats.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.freeradbiomed.2004.06.028DOI Listing

Publication Analysis

Top Keywords

bal cells
16
cells no2-exposed
12
superoxide radicals
12
impaired superoxide
8
superoxide radical
8
bronchoalveolar lavage
8
no2-exposed rats
8
production superoxide
8
enzyme activities
8
exposed days
8

Similar Publications

Extracellular peroxiredoxin 6 released from alveolar epithelial cells as a DAMP drives macrophage activation and inflammatory exacerbation in acute lung injury.

Int Immunopharmacol

January 2025

Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai 200032, China; Department of Pulmonary Medicine, Zhongshan Hospital (Xiamen), Fudan University, Xiamen, Fujian 361015, China; Shanghai Key Laboratory of Lung Inflammation and Injury, Department of Pulmonary Medicine, Zhongshan Hospital, Fudan University, Shanghai 200032, China; Shanghai Respiratory Research Institute, Shanghai 200032, China.

Acute respiratory distress syndrome (ARDS) is featured with acute lung inflammatory injury. Our prospective study found that higher levels of peroxiredoxin 6(PRDX6) were detected in bronchoalveolar lavage (BAL) fluid from ARDS patients. Elevated PRDX6 was also correlated with monocytic activation and poor prognosis in ARDS patients.

View Article and Find Full Text PDF

Airway MMP-12 and DNA methylation in COPD: an integrative approach.

Respir Res

January 2025

Department of Public Health and Clinical Medicine, Section of Medicine, Umeå University, 901 87, Umeå, Sweden.

Background: In COPD, the balance between matrix metalloproteinases (MMPs) and their natural inhibitors [tissue inhibitors of metalloproteinases (TIMPs)] is shifted towards excessive degradation, reflected in bronchoalveolar lavage (BAL) as increased MMP concentrations. Because of their critical role in lung homeostasis, MMP activity is tightly regulated, but to what extent this regulation occurs through epigenetic mechanisms remains unknown.

Methods: To explore the interplay between MMPs, TIMPs, and DNA methylation (DNAm) we (1) analysed MMP-9, -12, and TIMP-1 concentrations in BAL fluid, and profiled DNAm in BAL cells from 18 COPD and 30 control subjects, (2) estimated protein-COPD relationships using multivariable regression, (3) identified protein quantitative trait methylation loci (pQTMs) with COPD as a potential modifier in a separate interaction model, and (4) integrated significant interactions with a previous COPD GWAS meta-analysis.

View Article and Find Full Text PDF

Background: Airway inflammation has a critical role in asthma pathogenesis and pathophysiology. Yet, the molecular pathways contributing to airway inflammation are not fully known, particularly Type-2 (T2) inflammation characterized by both eosinophilia and higher FeNO levels.

Objective: To identify genes whose level of expression in epithelial brushing samples were associated with both bronchoalveolar lavage (BAL) eosinophilia and generation of FeNO.

View Article and Find Full Text PDF

Hematopoietic stem cells must mitigate myriad stressors throughout their lifetime to ensure normal blood cell generation. Here, we uncover unfolded protein response stress sensor inositol-requiring enzyme-1α (IRE1α) signaling in hematopoietic stem and progenitor cells (HSPCs) as a safeguard against myeloid leukemogenesis. Activated in part by an NADPH oxidase-2 mechanism, IRE1α-induced X-box binding protein-1 (XBP1) mediated repression of pro-leukemogenic programs exemplified by the Wnt-β-catenin pathway.

View Article and Find Full Text PDF

SARS-CoV-2 infection induces a humoral immune response, producing virus-specific antibodies such as IgM, IgG, and IgA. IgA antibodies are present at mucosal sites, protecting against respiratory and other mucosal infections, including SARS-CoV-2, by neutralizing viruses or impeding attachment to epithelial cells. Since SARS-CoV-2 spreads through the nasopharynx, the specific IgAs of SARS-CoV-2 are produced quickly after infection, effectively contributing to virus neutralization.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!