Hydrogen peroxide generation by eosinophils in allergic rhinitis

Low Level of Advanced Glycation End Products in Serum of Patients with Allergic Rhinitis and Chronic Epstein-Barr Virus Infection at Different Stages of Virus Persistence

Advanced glycation end products (AGEs) are formed in a nonenzymatic reaction of the reducing sugars with amino groups of proteins, lipids, and nucleic acids of different tissues and body fluids. A relatively small number of studies have been conducted on the role of AGEs in allergic inflammation. In this study, patients with allergic rhinitis (AR) were examined for the presence of Epstein-Barr virus and the content of fluorescent and nonfluorescent AGEs. We have also determined the level of a unique epitope (AGE10) which was recently identified in human serum using monoclonal antibodies against synthetic melibiose-derived AGE (MAGE). The levels of AGE10 determined with an immunoenzymatic method revealed no significant difference in the patients' blood with intermittent AR and chronic EBV persistence in the active and latent phases. It has been shown that there is a statistically significantly smaller amount of AGEs and pentosidine in groups of patients, both with and without viremia, than in healthy subjects. In turn, higher levels of immune complexes than of AGE10 were detected in the groups of patients, in contrast to the control group, which had lower levels of complexes than AGE10 concentration. In patients with active infection, there is even more complexes than of noncomplexed AGE10 antigen. The lower level of AGE in allergic rhinitis patient sera may also be due, besides complexes, to allergic inflammation continuously activating the cells, which effectively remove glycation products from the body.

Effects of Low-Level Laser Irradiation in a Mouse Model of Allergic Rhinitis

BACKGROUND AND OBJECTIVES

To evaluate the antiallergic effect of low-level laser irradiation (LLLI) at 650 nm in a mouse model of allergic rhinitis (AR), and to examine the underlying mechanisms.

STUDY DESIGN/MATERIALS AND METHODS

BALB/c mice were sensitized with ovalbumin (OVA) and alum and challenged intranasally with OVA. Straight- and diffusion-type LLLI were applied directly into the intranasal cavity of the mice once daily for 10 days (650 nm, 5 mW, 15 min/day) and multiple allergic parameters were evaluated.

RESULTS

LLLI reduced allergic symptoms, such as rubbing and sneezing, and suppressed the serum total immunoglobulin E (IgE), OVA-specific IgE, and OVA-specific IgG1 levels. Diffusion-type LLLI significantly reduced eosinophil infiltration of nasal mucosa and lymph nodes (LNs). LLLI reduced the expression of interleukin-4 (IL-4) and IL-17 in cervical LN and splenocyte culture supernatant, as well as their messenger RNA levels in nasal mucosa. However, the expression of interferonγ (IFN-γ) and IL-6 was unaffected by LLLI. The levels of reactive oxygen species (ROS) and nitric oxide (NO) in LN cells and the nasal mucosa, which were increased in the AR group, were reduced by LLLI, suggesting involvement of ROS and NO within their mechanism.

CONCLUSIONS

LLLI exerted an antiallergic effect by decreasing local and systemic IL-4, IL-17, and IgE levels, as well as eosinophilic infiltration into the nasal mucosa, in a mouse model of AR by modulating ROS and NO levels. Diffusion-type LLLI exhibited greater efficacy against AR than straight-type LLLI. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

"Cumulative Stress": The Effects of Maternal and Neonatal Oxidative Stress and Oxidative Stress-Inducible Genes on Programming of Atopy

Although extensive epidemiological and laboratory studies have been performed to identify the environmental and immunological causes of atopy, genetic predisposition seems to be the biggest risk factor for allergic diseases. The onset of atopic diseases may be the result of heritable changes of gene expression, without any alteration in DNA sequences occurring in response to early environmental stimuli. Findings suggest that the establishment of a peculiar epigenetic pattern may also be generated by oxidative stress (OS) and perpetuated by the activation of OS-related genes. Analyzing the role of maternal and neonatal oxidative stress and oxidative stress-inducible genes, the purpose of this review was to summarize what is known about the relationship between maternal and neonatal OS-related genes and the development of atopic diseases.

Comparison of pre- and post-operative stress levels in patients with allergic rhinitis and non-allergic rhinitis

The effects of stressful events, such as surgery, on patients with allergic diseases are unclear. The aim of this study was to evaluate whether patients with allergic rhinitis (AR) are more susceptible to stress and oxidative stress than non-allergic individuals. 20 AR patients and 20 non-allergic rhinitis (NAR) patients were recruited to this study and underwent nasal septoplasty. To evaluate the degrees of stress and oxidative stress, we collected urine and blood samples 1 day before and 1 day after surgery. Stress was assessed by measuring urine cortisol levels. Oxidative stress was assessed by calculating the balance of reactive oxygen metabolites (ROM) measured by the diacron reactive oxygen metabolites test, and antioxidant capacity (AC) was measured by the biological antioxidant potential test. In both groups, the level of post-operative urine cortisol was significantly higher than the pre-operative level, with no significant difference between the two groups. ROM levels were significantly higher in both groups after surgery than before surgery. The antioxidant capacity of the AR group was lower after surgery than before surgery, while it was greater in the NAR group after surgery. There were no significant differences in pre- or post-operative ROM or AC levels between the two groups. The ROM/AC ratio was significantly higher after surgery in the AR group than it was in the NAR group. The post-operative ROM/AC imbalance of AR patients suggests that these patients might be vulnerable to stress, especially oxidative stress.

DNA damage in children with asthma bronchiale and its association with oxidative and antioxidative measurements

Increased production of reactive oxygen species leading to an imbalance between the oxidative forces and the antioxidant defense systems favoring an oxidative injury has been implicated in the pathogenesis of asthma. The aim of the study was to investigate the peripheral DNA damage, and its association with oxidative and antioxidative measurements in children with asthma bronchiale. The study population contained 42 children with asthma bronchiale and 32 healthy controls. DNA damage was assessed by alkaline comet assay in peripheral lymphocytes. Plasma levels of total antioxidant status (TAS), total peroxide concentration (LOOHs), and total oxidant status (TOS) were determined. In asthma bronchiale patients, DNA damage was significantly higher than in controls (17.9 +/- 11.8 AU vs. 1.2 +/- 2.0 AU, p < 0.001). Plasma TOS and LOOHs were higher in patients than in healthy controls (13.4 +/- 7.0 vs. 9.0 +/- 3.5, p = 0.002; 9.9 +/- 3.4 vs. 4.4 +/- 1.5, p < 0.001, respectively). Plasma TAS level in patients was higher than in healthy controls (5.5 +/- 2.5 vs. 1.0 +/- 0.6, p < 0.001). DNA damage was correlated with TOS (r = 0,616, p < 0.001). The findings indicated that lymphocyte DNA damage level increases in children with asthma bronchiale. Elevated DNA damage may be related to increased oxidative stress. However, the mechanism of this association, and whether it is direct or indirect, remains to be explored.

Oxidative microenvironment exerts an opposite regulatory effect on cytokine production by Th1 and Th2 cells

Oxidative stress occurs in allergic disorders and immunologic inflammatory responses and reactive oxygen metabolites have an additional role of cell-signaling mediators, influencing many biological processes. Using in vitro derived Th1 and Th2 clones or T cells derived from autoimmune thyroiditis we study the ability of Th1 or Th2 cells to expand and produce cytokine in an oxidative environment. We found that low-doses of H2O2 reduce the INF-gamma production of activated Th1 clones and potentiate the IL-4 secretion of activated Th2 clones. These effects were not due to altered cell proliferation and are not transient, since the modified secretion profile was still retained after 1 week from H2O2 stimulation by both Th1 and Th2 cells. H2O2 influence the profile of cytokine secretion in both Th1 and Th2. These effects are long lasting and are the result of an action of H2O2 on T cell. In conclusion we demonstrate that oxidative stress plays an important role in the pathogenesis of allergic respiratory diseases and can up-regulate Th2-driven inflammation, thus contributing to increase disease severity, bronchial hyper-responsiveness and airway remodeling.

Effect of pollen-mediated oxidative stress on immediate hypersensitivity reactions and late-phase inflammation in allergic conjunctivitis

BACKGROUND

Allergic eye diseases are complex inflammatory conditions of the conjunctiva that are becoming increasingly prevalent and present an increasing economic burden because of direct and indirect health expenditures.

OBJECTIVE

We sought to identify factors that may synergize with antigen-induced allergic inflammation and lead to allergic conjunctivitis. We used a murine model of allergic conjunctivitis to test the effect of oxidative stress generated by pollen oxidases using nicotinamide adenine dinucleotide (reduced) or nicotinamide adenine dinucleotide phosphate (reduced) (NAD[P]H) as an electron donor present in pollen grains.

METHODS

Reactive oxygen species (ROS) generation by hydrated Ambrosia artemisiifolia pollen (short ragweed pollen; RWP) grains was determined by using 2'-7'-dihydro-dichlorofluorescein diacetate, nitroblue tetrazolium reduction, and Amplex Red assay. The RWP-induced changes in intracellular ROS levels were examined in A549 cells, human primary bronchial epithelial cells, and murine conjunctiva.

RESULTS

Ragweed pollen grains contain NAD(P)H oxidase activity, which is diphenyleneiodonium-sensitive and quinacrine-sensitive and sodium azide-resistant. These NAD(P)H oxidases generate a superoxide anion that can be converted to H2O2 by pollen grain-associated superoxide dismutase. These diffusible oxygen radicals from pollen grains increase intracellular ROS levels in cultured epithelial cells and murine conjunctiva. Similar phenomena were observed in sensitized and naive mice, indicating that the RWP-induced oxidative stress in conjunctival epithelium is independent of adaptive immunity. Inactivation of NAD(P)H oxidase activity in RWP decreases the immediate-type hypersensitivity and inflammatory cell infiltration into the conjunctiva.

CONCLUSION

Our data suggest that ROS generated by NAD(P)H oxidases in pollen grains intensify immediate allergic reactions and recruitment of inflammatory cells in murine conjunctiva.

Effect of nasal triamcinolone acetonide on lower airway inflammatory markers in patients with allergic rhinitis

BACKGROUND

Allergic rhinitis (AR) and asthma are commonly associated, and similar underlying inflammatory processes link both diseases. AR, even in the absence of asthma, is associated with increased levels of exhaled nitric oxide (ENO) and hydrogen peroxide (H(2)O(2)) in exhaled breath condensate, 2 noninvasive markers of lower airway inflammation.

OBJECTIVE

We sought to evaluate the effect of treatment with the nasal steroid triamcinolone acetonide on ENO and exhaled H(2)O(2) in subjects with AR.

METHODS

We allocated 23 subjects in a randomized, double-blind, parallel-controlled fashion to 4-week treatment with triamcinolone acetonide (220 microg/d) or matching placebo.

RESULTS

ENO levels were greater in the subgroup with concomitant asthma (16/23 subjects) and decreased significantly with triamcinolone acetonide treatment in this subgroup of patients in comparison with patients receiving placebo. Breath condensate levels of H(2)O(2) were higher in patients with AR without asthma than in those with asthma but decreased significantly with triamcinolone acetonide treatment in both subgroups. No changes were observed in bronchial hyperresponsiveness, nasal and asthma symptoms, or peak expiratory flow with active treatment or placebo.

CONCLUSION

We conclude that treatment of AR with triamcinolone acetonide results in decrease of 2 noninvasive markers of lower airway inflammation, ENO and H(2)O(2), supporting that upper and lower airway inflammation should be seen as a continuum in subjects with AR with and without asthma. ENO might be a more specific marker of the lower airway inflammation present in asthma.

Oxidative stress in allergic respiratory diseases

There is ample evidence that allergic disorders, such as asthma, rhinitis, and atopic dermatitis, are mediated by oxidative stress. Excessive exposure to reactive oxygen and nitrogen species is the hallmark of oxidative stress and leads to damage of proteins, lipids, and DNA. Oxidative stress occurs not only as a result of inflammation but also from environmental exposure to air pollution and cigarette smoke. The specific localization of antioxidant enzymes in the lung and the rapid reaction of nitric oxide with reactive oxygen species, such as superoxide, suggest that antioxidant enzymes might also function as cell-signaling agents or regulators of cell signaling. Therapeutic interventions that decrease exposure to environmental reactive oxygen species or augment endogenous antioxidant defenses might be beneficial as adjunctive therapies for allergic respiratory disorders.

Effect of hydrogen peroxide on guinea pig nasal mucosa vasculature

The effect of hydrogen peroxide (H2O2) on guinea pig nasal mucosa vasculature was studied by in vitro assay. H2O2 elicited relaxation of guinea pig nasal mucosa strips precontracted with phenylephrine in a concentration-dependent manner. The relaxant response to H2O2 was abolished in the presence of catalase. Preincubation of the strips with N(G)-nitro-L-arginine methyl ester or methylene blue significantly attenuated the relaxant responses elicited by H2O2. Fluorescence caused by DAF-2 DA, a fluorescence indicator for nitric oxide, was observed along the nasal mucosa vasculature in response to H2O2. These results suggest that H2O2 induced relaxation of the guinea pig nasal mucosa vasculature and that this relaxation is mediated by the NO/cGMP pathway.