Neutrophils in induced sputum from healthy children: role of interleukin-8 and oxidative stress

Oxidatively Damaged Nucleic Acid: Linking Diabetes and Cancer

Significance: Our current knowledge of the mechanism between diabetes and cancer is limited. Oxidatively damaged nucleic acid is considered a critical factor to explore the connections between these two diseases. Recent Advances: The link between diabetes mellitus and cancer has attracted increasing attention in recent years. Emerging evidence supports that oxidatively damaged nucleic acid caused by an imbalance between reactive oxygen species generation and elimination is a bridge connecting diabetes and cancer. 8-Oxo-7,8-dihydro-2'-deoxyguanosine and 8-oxo-7,8-dihydroguanosine assume important roles as biomarkers in assessing the relationship between oxidatively damaged nucleic acid and cancer. Critical Issues: The consequences of diabetes are extensive and may lead to the occurrence of cancer by influencing a combination of factors. At present, there is no direct evidence that diabetes causes cancer by affecting a single factor. Furthermore, the difficulty in controlling variables and differences in detection methods lead to poor reliability and repeatability of results, and there are no clear cutoff values for biomarkers to indicate cancer risk. Future Directions: A better understanding of connections as well as mechanisms between diabetes and cancer is still needed. Both diabetes and cancer are currently intractable diseases. Further exploration of the specific mechanism of oxidatively damaged nucleic acid in the connection between diabetes and cancer is urgently needed. In the future, it is necessary to further take oxidatively damaged nucleic acid as an entry point to provide new ideas for the diagnosis and treatment of diabetes and cancer. Experimental drugs targeting the repair process of oxidatively generated damage require an extensive preclinical evaluation and could ultimately provide new treatment strategies for these diseases. Antioxid. Redox Signal. 37, 1153-1167.

Adverse Environmental Exposure and Respiratory Health in Children

The burden imposed by pollution falls more on those living in low-income and middle-income countries, affecting children more than adults. Most air pollution results from incomplete combustion and contains a mixture of particulate matter and gases. Air pollution exposure has negative impacts on respiratory health. This article concentrates on air pollution in 2 settings, the child's home and the ambient environment. There is an inextricable 2-way link between air pollution and climate change, and the effects of climate change on childhood respiratory health also are discussed.

Biomarkers of nucleic acid oxidation - A summary state-of-the-art

Oxidatively generated damage to DNA has been implicated in the pathogenesis of a wide variety of diseases. Increasingly, interest is also focusing upon the effects of damage to the other nucleic acids, RNA and the (2′-deoxy-)ribonucleotide pools, and evidence is growing that these too may have an important role in disease. LC-MS/MS has the ability to provide absolute quantification of specific biomarkers, such as 8-oxo-7,8-dihydro-2′-deoxyGuo (8-oxodG), in both nuclear and mitochondrial DNA, and 8-oxoGuo in RNA. However, significant quantities of tissue are needed, limiting its use in human biomonitoring studies. In contrast, the comet assay requires much less material, and as little as 5 μL of blood may be used, offering a minimally invasive means of assessing oxidative stress in vivo, but this is restricted to nuclear DNA damage only. Urine is an ideal matrix in which to non-invasively study nucleic acid-derived biomarkers of oxidative stress, and considerable progress has been made towards robustly validating these measurements, not least through the efforts of the European Standards Committee on Urinary (DNA) Lesion Analysis. For urine, LC-MS/MS is considered the gold standard approach, and although there have been improvements to the ELISA methodology, this is largely limited to 8-oxodG. Emerging DNA adductomics approaches, which either comprehensively assess the totality of adducts in DNA, or map DNA damage across the nuclear and mitochondrial genomes, offer the potential to considerably advance our understanding of the mechanistic role of oxidatively damaged nucleic acids in disease.

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Oxidatively damaged nucleic acids are implicated in the pathogenesis of disease.

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LC-MS/MS, comet assay and ELISA are often used to study oxidatively damaged DNA.

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Urinary oxidatively damaged nucleic acids non-invasively reflect oxidative stress.

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DNA adductomics will aid understanding the role of ROS damaged DNA in disease.

Anti-inflammatory effects of salmeterol/fluticasone propionate 50/250 mcg combination therapy in Japanese patients with chronic obstructive pulmonary disease

PURPOSE

Using sputum neutrophils as the primary measure, and other inflammation biomarkers, this study evaluated the anti-inflammatory effects of the combination salmeterol 50 mcg and fluticasone propionate 250 mcg (SFC 250) in Japanese patients with chronic obstructive pulmonary disease (COPD).

PATIENTS AND METHODS

Patients were treated in a randomized, double-blind, parallel group, placebo-controlled trial with SFC 250 twice daily (n=26) or placebo (n=26) for 12 weeks. At the start and end of treatment, inflammation biomarkers (sputum and serum), lung function, and health status (COPD Assessment Test [CAT] questionnaire) were measured.

RESULTS

Although a numerical decrease in differential neutrophil count was observed from baseline, SFC 250 did not significantly reduce sputum neutrophils compared with placebo, nor were there significant changes from baseline in the other biomarkers (sputum or serum), lung function, or CAT, versus placebo. Squamous epithelial cell contamination in some sputum samples rendered them unacceptable for analysis, which reduced the sample size to n=19 (SFC 250) and n=10 (placebo). However, inclusion of contaminated samples did not affect the overall trend of the outcome. Ad hoc bootstrap statistical analysis showed a 27.9% (SFC 250) and 1.3% (placebo) decrease in sputum neutrophils. Sputum IL-8 decreased by 43.2% after SFC 250 but increased by 48.3% with placebo. Responder analyses showed 42% of patients had ≥20% decrease in neutrophils from baseline; and 47% of patients had a ≥200 pg/mL change in sputum IL-8 following SFC 250 versus 20% after placebo; both changes are considered clinically relevant.

CONCLUSION

This study provides additional information about inflammation in Japanese COPD patients and is the first to study the anti-inflammatory effects of SFC 250 in this context and population. In the primary analysis, SFC 250 did not produce significant changes from baseline in sputum neutrophil levels or other sputum or serum inflammatory markers compared with placebo. Secondary ad hoc statistical analysis showed that SFC 250 reduced the number of sputum neutrophils and IL-8 compared with placebo.

Induced sputum cell count and cytokine profile in atopic and non-atopic children with asthma

BACKGROUND AND AIM

Sputum induction is a semi-invasive technique used to detect and monitor airway inflammation. In this study, the cell profile, and Th1 and Th2 cytokine levels in induced sputum of asthmatic and healthy children (HC) are compared.

METHODS

Sputum induction was performed in healthy and asthmatic children by inhalation of hypertonic saline solution. Differential cell count in the specimen obtained was carried out using optic microscopy. IFN-γ, IL-2, IL-10, IL-8, IL-6, IL-4, IL-5, IL-1β, TNF-α, and IL-12p70 levels were determined in sputum sample supernatants by flow cytometry.

RESULTS

Sputum induction was performed in 31 HC and 77 asthmatic children (60 atopic and 17 non-atopic asthma, NAA). Twenty-four samples were obtained in HC and 64 in patients. Median eosinophil count in atopic asthma (AA; 2%) was higher than in NAA (P = 0.02) or HC (P = 0.01). IL-4, IL-5, IFNγ, IL-2, and IL-12p70 concentrations were higher in AA than in NAA or HC. IL-8 was higher in asthmatic children (atopic and non-atopic) than in healthy ones. IL-10 was higher in the healthy group than in the AA group (P = 0.02).

CONCLUSIONS

As compared to HC, the inflammatory profile in induced sputum of children with asthma showed an increase in proinflammatory cytokines. Concentrations of IL-10, an anti-inflammatory cytokine, were lower in children with AA than in HC.

Induced sputum evaluation in restorers and conservators of cultural heritage

The objective of this study was to examine induced sputum (IS) cells profile from restorers/conservators of cultural heritage (restorers) with no lower airway symptoms and normal ventilatory lung function. The study involved 22 restorers and 48 control workers. Medical interview, physical examination, spirometry, skin prick testing to inhalatory allergens, and IS collection were performed. Compared with control workers, restorers demonstrated higher percentage of neutrophils (34% vs 15.5%; p = .004). This pattern was found only in male workers. They had almost 9 times greater chance to have increased proportion of sputum neutrophils than male controls (odds ratio [OR] 8.98, 95% confidence interval [CI] 1.98-40.7). The mobilization of eosinophils or macrophages into the airways was not established regardless of workers sex. Additional gender difference in sputum cells distribution was found for occupationally unexposed subjects, with higher proportion of sputum neutrophils in women.

Age-related increase of airway neutrophils in older healthy nonsmoking subjects

BACKGROUND

Although an influence of advancing age on lung cellularity in healthy subjects has already been described, induced sputum reference values for cell counts in older healthy adults are not available. The aim of the present study was to evaluate the influence of age on the variation of sputum cell distribution in a considerable number of healthy subjects. A total of 70 nonatopic, nonsmoker healthy subjects aged ≥50 years underwent sputum induction and blood cell count. Sputum samples were processed and then were analyzed by optical microscopy. Differential cell counts were reported as percentages and amount of cells/mg.

RESULTS

Sputum cell distribution of healthy subjects aged ≥50 years was mainly composed of neutrophils. Both the percentage and the amount of sputum neutrophils correlated with the subjects' age, r=0.5, p=0.00001 and r=0.32, p=0.007, respectively. This correlation was more evident in women (n=35) than in men (n=35). No correlation was found between blood neutrophils and age. The increase in sputum neutrophils was not secondary to an increase in blood neutrophils.

CONCLUSIONS

In the studied subjects, aging was associated, particularly in women, with an increase in sputum neutrophils not related to an increase of blood neutrophils. These results could be useful in clinical and experimental settings as reference values to compare with data from subjects aged over 50 years. These data showed that sputum neutrophila can be dissociated from airway symptoms and could create a favorable background for the development of age-related lung diseases.

Neutrophilic airway inflammation is a main feature of induced sputum in nonatopic asthmatic children

BACKGROUND

Asthma phenotypes are well described among children. However, there are few studies comparing airway inflammation in different clinical presentations of pediatric asthma. We tested the hypothesis that nonatopic asthma is associated with a predominant noneosinophilic inflammation in the airways, as assessed by induced sputum. The objective of this study was to evaluate the cytological characteristics of induced sputum (IS) in atopic (AA), nonatopic asthmatics (NAA) and nonatopic nonasthmatic children (NANA).

METHODS

Of 90 selected children, 77 met eligibility criteria for performing IS and were classified as: AA, n = 28, NAA, n = 29 and NANA, n = 19. Subjects answered to a set of ISAAC-based questions and were skin-tested for common aeroallergens. A defined series of exclusion criteria was applied.

RESULTS

Induced sputum was obtained from 54 (70.1%) subjects (21 AA, 20 NAA and 13 NANA). Demographic data and mean FEV(1) were similar in the three groups. The proportion of eosinophils [median, inter quartile range (IQR)] was significantly higher in the sputum of AA [(6.0.)12)] compared with NAAs [0 (2)] and NANAs [0 (1)], P < 0.001. The proportion of children with sputum eosinophilia (eos > 3%) was also significantly higher in AA (71.4%) when compared with NAA (28.6%); none of the NANA had sputum eosinophilia. Nonatopic asthmatic children had significantly higher proportions and absolute number of neutrophils than AA and controls.

CONCLUSIONS

The results suggest that nonatopic children present IS with a cell pattern that is predominantly neutrophilic while eosinophilia is the hallmark of airway inflammation in the majority of atopic wheezing children not treated with inhaled steroids.

Sources of extracellular, oxidatively-modified DNA lesions: implications for their measurement in urine

There is a robust mechanistic basis for the role of oxidation damage to DNA in the aetiology of various major diseases (cardiovascular, neurodegenerative, cancer). Robust, validated biomarkers are needed to measure oxidative damage in the context of molecular epidemiology, to clarify risks associated with oxidative stress, to improve our understanding of its role in health and disease and to test intervention strategies to ameliorate it. Of the urinary biomarkers for DNA oxidation, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) is the most studied. However, there are a number of factors which hamper our complete understanding of what meausrement of this lesion in urine actually represents. DNA repair is thought to be a major contributor to urinary 8-oxodG levels, although the precise pathway(s) has not been proven, plus possible contribution from cell turnover and diet are possible confounders. Most recently, evidence has arisen which suggests that nucleotide salvage of 8-oxodG and 8-oxoGua can contribute substantially to 8-oxoG levels in DNA and RNA, at least in rapidly dividing cells. This new observation may add an further confounder to the conclusion that 8-oxoGua or 8-oxodG, and its nucleobase equivalent 8-oxoguanine, concentrations in urine are simply a consequence of DNA repair. Further studies are required to define the relative contributions of metabolism, disease and diet to oxidised nucleic acids and their metabolites in urine in order to develop urinalyis as a better tool for understanding human disease.

The production of reactive oxygen species in peripheral blood neutrophils is modulated by airway mucous

Neutrophils are a major source of reactive oxygen species (ROS). The role of airway mucous on ROS production is unknown. The aim of our study was to investigate the direct influence of bronchoalveolar lavage fluid (BALF) and induced sputum (IS) alone or in combination with chemical/biological stimulus on ROS production in peripheral blood neutrophils during chronic obstructive pulmonary disease (COPD). Neutrophils were isolated from peripheral blood of 47 patients with moderate COPD and 14 healthy individuals (HI). BALF/RPMI (1:1) or IS/RPMI (1:1) from COPD patients were used to stimulate neutrophils alone or in combination with phorbolmyristate- acetate (PMA) (0.1–30 nM) or Staphylococcus aureus bacteria (0.7–500 bact/neutrophil). Relative generation of ROS was measured flow cytometrically. BALF/RPMI and in combination with relatively low PMA or all bacteria concentrations stimulated ROS; while, combination with relatively high PMA concentrations suppressed ROS in of COPD patients and HI. IS/RPMI and its combination with PMA inhibited ROS generation in both groups; whereas, IS stimulated or had a tendency to stimulate ROS production with relatively high bacteria concentrations. In conclusion, BALF and IS directly or in combination with chemical/biological factors modulated ROS production. This effect was stronger in neutrophils from COPD patients and depended on chemical/biological stimulus intensity.