Desferrioxamine modulates chemically induced T helper 2-mediated autoimmunity in the rat

Exposure to air pollution and incidence of atopic dermatitis in the general population: A national population-based retrospective cohort study

BACKGROUND

To date, little evidence is available to determine whether atopic dermatitis (AD) can be caused by exposure to air pollutants, including gases and particulate matter.

OBJECTIVE

We aimed to evaluate the relationship between air pollutants and incidence of AD using the National Health Insurance Service-National Sample Cohort database.

METHODS

We included 209,168 subjects from the general population previously not diagnosed with AD between 2008 and 2013. Long-term average concentration of air pollutants before diagnosis was calculated for each subject.

RESULTS

For 1,030,324 person-years, incident cases of AD were observed in 3203 subjects. There was a significant positive association between incidence of AD and long-term average concentration of particulate matter smaller than 2.5 μm in diameter (hazard ratio [HR], 1.420; 95% CI, 1.392-1.448; for 1 μg/m³), particulate matter smaller than 10 μm in diameter (HR, 1.333, 95% CI, 1.325-1.341; for 1 μg/m³), sulfur dioxide (HR, 1.626; 95% CI, 1.559-1.695; for 1 parts per billion), nitrogen dioxide (HR, 1.200; 95% CI, 1.187-1.212; for 1 parts per billion), and carbon monoxide (HR, 1.005; 95% CI, 1.004-1.005; for 1 parts per billion) after adjusting for age, sex, income, comorbid diseases, and meteorologic variables.

LIMITATIONS

The National Health Insurance Service database lacks detailed information on individual subjects.

CONCLUSIONS

This study demonstrated that long-term exposure to air pollutants, including gases and particulate matter, is an independent risk factor for developing AD.

Nutritional immunity: the impact of metals on lung immune cells and the airway microbiome during chronic respiratory disease

Nutritional immunity is the sequestration of bioavailable trace metals such as iron, zinc and copper by the host to limit pathogenicity by invading microorganisms. As one of the most conserved activities of the innate immune system, limiting the availability of free trace metals by cells of the immune system serves not only to conceal these vital nutrients from invading bacteria but also operates to tightly regulate host immune cell responses and function. In the setting of chronic lung disease, the regulation of trace metals by the host is often disrupted, leading to the altered availability of these nutrients to commensal and invading opportunistic pathogenic microbes. Similarly, alterations in the uptake, secretion, turnover and redox activity of these vitally important metals has significant repercussions for immune cell function including the response to and resolution of infection. This review will discuss the intricate role of nutritional immunity in host immune cells of the lung and how changes in this fundamental process as a result of chronic lung disease may alter the airway microbiome, disease progression and the response to infection.

Keratinocytes-Derived Reactive Oxygen Species Play an Active Role to Induce Type 2 Inflammation of the Skin: A Pathogenic Role of Reactive Oxygen Species at the Early Phase of Atopic Dermatitis

Background

Atopic dermatitis (AD) is characterized by chronic, relapsing skin inflammation (eczema) with itchy sensation. Keratinocytes, which are located at the outermost part of our body, are supposed to play important roles at the early phase of type 2 inflammation including AD pathogenesis.

Objective

The purpose of this study was to evaluate whether keratinocytes-derived reactive oxygen species (ROS) could be produced by the allergens or non-allergens, and the keratinocytes-derived ROS could modulate a set of biomarkers for type 2 inflammation of the skin.

Methods

Normal human epidermal keratinocytes (NHEKs) were treated with an allergen of house dust mites (HDM) or a non-allergen of compound 48/80 (C48/80). Then, biomarkers for type 2 inflammation of the skin including those for neurogenic inflammation were checked by reverse transcriptase-polymerase chain reaction and western immunoblot experiments.

Results

HDM or C48/80 was found to upregulate expression levels of our tested biomarkers, including type 2 T helper-driving pathway (KLK5, PAR2, and NFκB), epithelial-cell-derived cytokines (thymic stromal lymphopoietin, interleukin [IL]-25, IL-33), and neurogenic inflammation (NGF, CGRP). The HDM- or C-48/80-induced expression levels of the biomarkers could be blocked by an antioxidant treatment with 5 mM N-acetyl-cysteine. In contrast, pro-oxidant treatment with 1 mM H₂O₂ could upregulate expression levels of the tested biomarkers in NHEKs.

Conclusion

Our results reveal that keratinocytes-derived ROS, irrespective to their origins from allergens or non-allergens, have a potential to induce type 2 inflammation of AD skin.

Correction of iron deficiency anaemia using IV CosmoFer in CKD patients with asthma: a prospective study

BACKGROUND

Intravenous (IV) iron is commonly used for correcting iron deficiency anaemia in patients with chronic kidney disease (CKD). There remains a concern for its use in patients with asthma as it may trigger an acute exacerbation. Pre-treatment with a single dose of parenteral hydrocortisone may obviate this risk.

METHOD

We carried out a prospective study of known asthmatic patients with CKD requiring single-dose iron repletion therapy. We analysed the efficacy and safety of IV CosmoFer (low molecular weight iron dextran). Twenty non-dialysis CKD patients with iron deficiency anaemia and a history of asthma were enrolled. Severity of asthma and level of control were recorded as per British Thoracic Society Guidelines and Royal Collage of Physician questionnaire, respectively. All patients received IV hydrocortisone 30 min before the test dose of CosmoFer followed by the remaining total dose. Patients were monitored for adverse reactions. Haemoglobin, serum ferritin levels and estimated glomerular filtration rate were measured pre and 6-weeks post-infusion. All patients were followed up until 6 weeks to assess the control of their asthma.

RESULTS

All 20 patients completed the study. No patient experienced acute hypersensitivity or infusion reactions. At 6 weeks follow-up, no patient reported worsening of their asthma. There was an increase in mean haemoglobin from 10.1 to 11.1 g/dl and mean ferritin from 93.5 to 302.6 ng/ml.

CONCLUSIONS

This study demonstrates that IV CosmoFer may be administered safely in asthmatics by administering a single 50 mg dose of hydrocortisone pre-infusion.

Oxidative Stress in Atopic Dermatitis

Atopic dermatitis (AD) is a chronic pruritic skin disorder affecting many people especially young children. It is a disease caused by the combination of genetic predisposition, immune dysregulation, and skin barrier defect. In recent years, emerging evidence suggests oxidative stress may play an important role in many skin diseases and skin aging, possibly including AD. In this review, we give an update on scientific progress linking oxidative stress to AD and discuss future treatment strategies for better disease control and improved quality of life for AD patients.

Oxidative stress parameters and serum magnesium levels in patients with seasonal allergic conjunctivitis

OBJECTIVE

To evaluate oxidative stress parameters and serum magnesium (Mg) levels in patients with seasonal allergic conjunctivitis (SAC) during the pollen season.

METHODS

This observational cross-sectional study involved 35 patients with SAC without any other ocular and systemic diseases, and 38 consecutive, age- and sex-matched healthy subjects. Serum malondialdehyde (MDA), adjusted ischemia modified albumin (IMA), and Mg levels were quantified, and the results were compared between the groups.

RESULTS

No significant differences were found between the groups with respect to age (p = 0.416) and sex (p = 0.362). Serum MDA and adjusted IMA levels of the subjects with SAC (69.54 ± 7.71 μM and 0.74 ± 0.39 ABSU) were significantly higher than the control group (64.61 ± 5.89 μM and 0.57 ± 0.19 ABSU) (p = 0.002 and p = 0.025, respectively). There was no significant difference for serum Mg levels between the groups (p = 0.177).

CONCLUSION

We demonstrated higher levels of oxidative stress parameters in patients with SAC compared to the control group, which imply a possible role of oxidative stress in the pathogenesis of SAC.

The role of air pollutants in atopic dermatitis

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease and a growing health concern, especially in children, because of its high prevalence and associated low quality of life. Genetic predisposition, environmental triggers, or interactions between them contribute to the pathophysiology of AD. Therefore, it is very important to identify and control risk factors from the environment in susceptible subjects for successful treatment and prevention. Both indoor and outdoor air pollution, which are of increasing concern with urbanization, are well-known environmental risk factors for asthma, whereas there is relatively little evidence in AD. This review highlights epidemiologic and experimental data on the role of air pollution in patients with AD. Recent evidence suggests that a variety of air pollutants, such as environmental tobacco smoke, volatile organic compounds, formaldehyde, toluene, nitrogen dioxide, and particulate matter, act as risk factors for the development or aggravation of AD. These air pollutants probably induce oxidative stress in the skin, leading to skin barrier dysfunction or immune dysregulation. However, these results are still controversial because of the low number of studies, limitations in study design, inaccurate assessment of exposure and absorption, and many other issues. Further research about the adverse effects of air pollution on AD will help to expand our understanding and to establish a better strategy for the prevention and management of AD.

Zn/Ga-DFO iron-chelating complex attenuates the inflammatory process in a mouse model of asthma

Background

Redox-active iron, a catalyst in the production of hydroxyl radicals via the Fenton reaction, is one of the key participants in ROS-induced tissue injury and general inflammation. According to our recent findings, an excess of tissue iron is involved in several airway-related pathologies such as nasal polyposis and asthma.

Objective

To examine the anti-inflammatory properties of a newly developed specific iron–chelating complex, Zn/Ga−DFO, in a mouse model of asthma.

Materials and methods

Asthma was induced in BALBc mice by ovalbumin, using aluminum hydroxide as an adjuvant. Mice were divided into four groups: (i) control, (ii) asthmatic and sham-treated, (iii) asthmatic treated with Zn/Ga−DFO [intra-peritoneally (i/p) and intra-nasally (i/n)], and (iv) asthmatic treated with Zn/Ga−DFO, i/n only. Lung histology and cytology were examined. Biochemical analysis of pulmonary levels of ferritin and iron-saturated ferritin was conducted.

Results

The amount of neutrophils and eosinophils in bronchoalveolar lavage fluid, goblet cell hyperplasia, mucus secretion, and peri-bronchial edema, showed markedly better values in both asthmatic-treated groups compared to the asthmatic non-treated group. The non-treated asthmatic group showed elevated ferritin levels, while in the two treated groups it returned to baseline levels. Interestingly, i/n-treatment demonstrated a more profound effect alone than in a combination with i/p injections.

Conclusion

In this mouse model of allergic asthma, Zn/Ga−DFO attenuated allergic airway inflammation. The beneficial effects of treatment were in accord with iron overload abatement in asthmatic lungs by Zn/Ga−DFO. The findings in both cellular and tissue levels supported the existence of a significant anti-inflammatory effect of Zn/Ga−DFO.

Asthma pathophysiology was shown to be associated with iron overload.

A therapeutic effect of the novel iron–chelating complexes was demonstrated.

Histological and cytological markers of inflammation were studied.

The complexes could be administered intranasally or by intraperitonneal injections.

Iron administration reduces airway hyperreactivity and eosinophilia in a mouse model of allergic asthma

The prevalence of allergic diseases has increased dramatically during the last four decades and is paralleled by a striking increase in iron intake by infants in affluent societies. Several studies have suggested a link between increased iron intake and the marked increase in prevalence of allergic diseases. We hypothesized that the increased iron intake by infants offers an explanation for the increased prevalence of allergic disease in industrialized societies during the past four decades. A well-established mouse model of ovalbumin (OVA)-driven allergic asthma was used to test the effects of differences in iron intake and systemic iron levels on the manifestations of allergic asthma. Surprisingly, iron supplementation resulted in a significant decrease in airway eosinophilia, while systemic iron injections lead to a significant suppression of both allergen-induced airway eosinophilia and hyperreactivity compared to placebo. In contrast, mice fed on an iron-deprived diet did not show any difference in developing experimentally induced allergic asthma when compared to those fed on an iron-sufficient control diet. In contrast to our hypothesis, airway manifestations of allergic asthma are suppressed by both increased levels of iron intake and systemic iron administrations in the mouse model.

Alternative therapeutic advantages of catfish bile on atopic dermatitis: protection of T cell-mediated skin disease via antioxidant activities

Objectives

In the present study, we aimed to examine the anti-atopic properties of bile from the cat fish, Silurus asotus, to determine its possible use as a pharmaceutical product.

Methods

The anti-atopic activities of cat fish bile were examined in a non-cell antioxidant, in-vitro assay (splenocytes and mast cells) and a 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis-like mouse model.

Results

The results of these experiments revealed that Silurus asotus bile (SAB) scavenges radicals and protects proteins from superoxide attacks, suggesting that SAB suppresses the T helper (Th) type 2-skewed immune response. Th1/Th2 mRNA cytokines (interleukin (IL)-2, interferon (IFN)-γ and IL-4) from mouse splenocytes were effectively inhibited, and the release of β-hexosaminidase in RBL-2H3 mast cells was significantly suppressed by SAB. These results were supported by screening the Th1/Th2 cytokine mRNAs (IL-2, IFN-γ and IL-4) from lymph nodes in DNCB-treated mice. More dramatic results were observed in the histological changes at higher SAB concentrations (5%) compared to the therapeutic control, visualized using hematoxylin–eosin (H&E) staining.

Conclusions

The results presented in this study suggest that SAB may provide functional advantages with regard to treating atopic dermatitis because of its antioxidant and immune-suppressive effects.

Redox imbalance in T cell-mediated skin diseases

The skin is permanently exposed to physical, chemical, and biological aggression by the environment. In addition, acute and chronic inflammatory events taking place in the skin are accompanied by abnormal release of pro-oxidative mediators. In this paper, we will briefly overview the homeostatic systems active in the skin to maintain the redox balance and also to counteract abnormal oxidative stress. We will concentrate on the evidence that a local and/or systemic redox dysregulation accompanies the chronic inflammatory disorder events associated to psoriasis, contact dermatitis, and atopic dermatitis. We will also discuss the fact that several well-established treatments for the therapy of chronic inflammatory skin disorders are based on the application of strong physical or chemical oxidants onto the skin, indicating that, in selected conditions, a further increase of the oxidative imbalance may lead to a beneficial outcome.

The iron chelator deferasirox protects mice from mucormycosis through iron starvation

Mucormycosis causes mortality in at least 50% of cases despite current first-line therapies. Clinical and animal data indicate that the presence of elevated available serum iron predisposes the host to mucormycosis. Here we demonstrate that deferasirox, an iron chelator recently approved for use in humans by the US FDA, is a highly effective treatment for mucormycosis. Deferasirox effectively chelated iron from Rhizopus oryzae and demonstrated cidal activity in vitro against 28 of 29 clinical isolates of Mucorales at concentrations well below clinically achievable serum levels. When administered to diabetic ketoacidotic or neutropenic mice with mucormycosis, deferasirox significantly improved survival and decreased tissue fungal burden, with an efficacy similar to that of liposomal amphotericin B. Deferasirox treatment also enhanced the host inflammatory response to mucormycosis. Most importantly, deferasirox synergistically improved survival and reduced tissue fungal burden when combined with liposomal amphotericin B. These data support clinical investigation of adjunctive deferasirox therapy to improve the poor outcomes of mucormycosis with current therapy. As iron availability is integral to the pathogenesis of other infections (e.g., tuberculosis, malaria), broader investigation of deferasirox as an antiinfective treatment is warranted.

The impact of stress on the development and expression of atopy

PURPOSE OF REVIEW

Biological hypersensitivity to environmental stimuli is a fundamental feature of atopy predisposing to a number of clinically expressed disorders including allergic rhinitis, atopic dermatitis or eczema, and allergic asthma. There is provocative evidence that psychological stress constitutes an increased risk for atopy. This risk is thought to be mediated by the effects of stress on neuroimmunoregulation which in turn modulates the hypersensitivity response. The primary objective is to review recent evidence updating our understanding of the role for psychological stress in atopy.

RECENT FINDINGS

The Th1-Th2 paradigm has been central to interpreting quantitative differences in cytokine expression in response to environmental stimuli like stress. Here we argue that examination of other mechanisms (e.g. oxidative stress pathways, glucocorticoid resistance, nerve-mast cell interactions, intestinal dysbiosis) and a broader range of cytokines and neuropeptides produced by cells both within and outside the immune system may better delineate the true complexity of the underlying mechanisms linking stress to allergic sensitization and asthma. The role of genetics and gene by environment interactions - based on evolving knowledge of candidate genes that may be relevant to both the stress response in general and pathways linked specifically to atopy - is also discussed.

SUMMARY

Psychological stress may be conceptualized as a social pollutant that, when 'breathed' into the body, may disrupt biological systems related to inflammation through mechanisms potentially overlapping with those altered by physical pollutants and toxicants.

Prenatal paracetamol exposure and risk of asthma and elevated immunoglobulin E in childhood

BACKGROUND

We recently found that paracetamol (acetaminophen) use in late pregnancy was associated with an increased risk of early wheezing in the offspring.

OBJECTIVE

To see whether use of paracetamol in late pregnancy is associated with an increased risk of asthma, wheezing and other atopic outcomes in the child at school age.

METHODS

In the population-based Avon Longitudinal Study of Parents and Children, we measured associations of paracetamol and aspirin use in late pregnancy (20-32 weeks) with asthma, hayfever, eczema (n = 8511) and wheezing (8381) in the offspring at 69-81 months, and with atopy (positive skin prick test to Dermatophagoides pteronyssinus, cat or grass, n = 6527) and blood total IgE (n = 5148) at 7 years. We used logistic and linear regression to analyse binary outcomes and log-transformed IgE, respectively, controlling for potential confounders.

RESULTS

Use of paracetamol, but not aspirin, in late pregnancy was positively associated with asthma (odds ratios (ORs), comparing children whose mothers took paracetamol 'sometimes' and 'most days/daily' with those whose mothers never took it, 1.22 (95% confidence interval (CI): 1.06-1.41) and 1.62 (95% CI: 0.86-3.04), respectively; P trend = 0.0037), wheezing (ORs 1.20 (95% CI: 1.02-1.40) and 1.86 (95% CI: 0.98-3.55), respectively; P trend = 0.011), and total IgE (geometric mean ratios 1.14 (95% CI: 1.03-1.26) and 1.52 (95% CI: 0.98-2.38), respectively; P trend = 0.0034), but not hayfever, eczema or skin test positivity. The proportion of asthma attributable to paracetamol use in late pregnancy, assuming a causal relation, was 7%.

CONCLUSION

Paracetamol exposure in late gestation may cause asthma, wheezing and elevated IgE in children of school age.