Oxidative stress induces MUC5AC expression through mitochondrial damage-dependent STING signaling in human bronchial epithelial cells.

Oxidative stress increases the production of the predominant mucin MUC5AC in airway epithelial cells and is implicated in the pathogenesis of bronchial asthma and chronic obstructive pulmonary disease. Oxidative stress impairs mitochondria, releasing mitochondrial DNA into the cytoplasm and inducing inflammation through the intracytoplasmic DNA sensor STING (stimulator of interferon genes). However, the role of innate immunity in mucin production remains unknown. We aimed to elucidate the role of innate immunity in mucin production in airway epithelial cells under oxidative stress. Human airway epithelial cell line (NCI-H292) and normal human bronchial epithelial cells were used to confirm MUC5AC expression levels by real-time PCR when stimulated with hydrogen peroxide (H2O2). MUC5AC transcriptional activity was increased and mitochondrial DNA was released into the cytosol by H2O2. Mitochondrial antioxidants were used to confirm the effects of mitochondrial oxidative stress where antioxidants inhibited the increase in MUC5AC transcriptional activity. Cyclic GMP-AMP synthase (cGAS) or STING knockout (KO) cells were generated to investigate their involvement. H2O2-induced MUC5AC expression was suppressed in STING KO cells, but not in cGAS KO cells. The epidermal growth factor receptor was comparably expressed in STING KO and wild-type cells. Thus, mitochondria and STING play important roles in mucin production in response to oxidative stress in airway epithelial cells.

Dupilumab Leads to Clinical Improvements including the Acquisition of Tolerance to Causative Foods in Non-Eosinophilic Esophagitis Eosinophilic Gastrointestinal Disorders.

A recent report showed that most pediatric cases of non-eosinophilic esophagitis (EoE) eosinophilic gastrointestinal disorders (EGIDs) (non-EoE EGIDs) are persistent and severe compared with those of EoE, thus requiring further effective therapeutic approaches. In this study, we present the first case based on a systematic search of non-EoE EGID for which tolerance to causative foods and histological and symptomatic improvements were achieved following dupilumab administration, after elimination diets and omalizumab and mepolizumab treatments. Driven by this case, we investigated the efficacies of biological treatments in non-EoE EGID cases based on the patient studied herein, and other patients identified in the conducted systematic review. Seven articles, including five different biologics, were reviewed. Both clinical efficacies and impact differences among the targeted molecules are demonstrated in this study. Our findings show that dupilumab may affect mechanisms that can suppress symptoms induced by offending foods that are different from those induced by other biologics as identified in the conducted systematic review. Additional studies are required to address the unmet needs of non-EoE EGID treatments.

Regional differences in the prevalence of oral allergy syndrome among Japanese children: A questionnaire-based survey.

BACKGROUND: Oral allergy syndrome (OAS) is characterized by an immediate allergic reaction that mainly or partially affects the oral mucosa, pharynx, or lips, and it is usually caused by ingesting fresh fruits or vegetables. Most patients with OAS also have allergic rhinitis due to pollen. As allergic rhinitis is increasingly prevalent in the Japanese population and the age at disease development is decreasing, morbidity associated with OAS among the younger population is likely to increase. However, there is little information about the prevalence of this disease among Japanese children, specifically the influences of residency in regions with different environments. OBJECTIVE: To investigate the prevalence of OAS and seasonal allergic rhinitis (SAR) among Japanese children and evaluate the relationship between OAS and SAR. METHODS: We administered a questionnaire-based survey among children aged 7-15 years, living in 4 cities in central Japan. RESULTS: The questionnaires were administered to 4103 children and completed by 3365 (82.0%). Overall, 524 children (15.6%) reported OAS-like symptoms after ingesting fruits or vegetables. The prevalence of seasonal SAR and oral symptoms significantly differed among the 4 cities. The total prevalence of oral symptoms co-occurring with SAR was 24.4%, which was significantly higher than the prevalence of symptoms occurring without SAR (10.2%, p < 0.001). CONCLUSIONS: Herein, oral symptoms were more likely to occur in patients with SAR than in those without SAR. The prevalence of SAR and food-induced oral symptoms significantly differed among the regions, suggesting they might be affected by regional differences in lifestyles and flora.

Expression of Leucine-rich Repeat-containing Protein 32 Following Lymphocyte Stimulation in Patients with Non-IgE-mediated Gastrointestinal Food Allergies.

The lymphocyte stimulation test (LST) facilitates the diagnosis of non-IgE-mediated gastrointestinal food allergies (non-IgE-GI-FAs). However, LSTs require large volumes of blood and prolonged culture durations. Recently, we found that IL2RA mRNA expression in peripheral blood mononuclear cells (PBMCs) of patients with non-IgE-GI-FAs increased after a 24 h stimulation with milk proteins. We designated this gene expression test as the instant peripheral blood allergen stimulation test (iPAST). In this study, we investigated whether other activated T cell-associated genes are superior to IL2RA in the iPAST for the supplementary diagnosis of non-IgE-GI-FAs. After incubating PBMCs with milk proteins for 24 h, the mRNA levels of three genes, LRRC32, TNFRSF4, and CD69, were assessed using quantitative RT-PCR. The diagnostic significance of the mRNA expression was evaluated by analyzing the receiver operating characteristic (ROC) curve. Upon stimulation with α-casein, κ-casein, α-lactalbumin, or a mixture of four milk protein components (Pmix), LRRC32 expression in the PBMCs of 16 patients with non-IgE-GI-FAs was found to be higher than that in their 17 control counterparts, whereas TNFRSF4 and CD69 levels remained unaltered. Except for ß-lactoglobulin and cow's milk (CM), the area under the ROC curve (AUC) for LRRC32 mRNA expression upon stimulation was >0.7, which validated the diagnostic ability of this test. Notably, α-casein and Pmix had higher AUC scores of 0.820 and 0.842, respectively, than other antigens. iPAST assessed by LRRC32 as well as IL2RA may be useful for the supplementary diagnosis of non-IgE-GI-FAs as an alternative to LSTs and provide insight into the pathogenesis of non-IgE-GI-FAs.

[SWITCHING BIOLOGICS LED TO GOOD CONTROL IN SEVERE CHILDHOOD ASTHMA: A CASE REPORT].

The two biologic therapies, anti-IgE (omalizumab) and anti-IL-5 antibodies (mepolizumab), are used in the treatment of severe pediatric asthma. We present here a case study of a 13-year-old girl with severe asthma who switched from omalizumab to mepolizumab therapy and achieved good control over her asthma. The patient was diagnosed with asthma at one year of age and presented with poor disease control, even while taking high doses of inhaled corticosteroids (ICS). As such, she was considered to have severe persistent asthma. At 10 years old, she began omalizumab therapy which improved asthma control. However, after two years of this therapy, she manifested frequent acute exacerbations. At 12 years old, she switched to mepolizumab and has since maintained good control of asthma. Additionally, total serum IgE levels and peripheral eosinophil counts decreased. As the underlying mechanisms of omalizumab and mepolizumab therapy are distinct, it is recommended to use either one if the other proves ineffective.

Severity scales of non-IgE-mediated gastrointestinal food allergies in neonates and infants.

BACKGROUND: Non-IgE-mediated gastrointestinal food allergies (non-IgE-GI-FAs) are one type of food allergy found in neonates and infants. Few reports have defined the severity of non-IgE-GI-FAs in these populations. METHODS: Grading scales of the severity of non-IgE-GI-FAs according to extra-GI symptoms, such as poor weight gain, as well as systemic symptoms, including fever and shock, were developed and retrospectively applied to patients with non-IgE-GI-FAs. The relationship between the severity of non-IgE-GI-FAs and both clinical and laboratory findings were examined. RESULTS: Elevation of C-reactive protein levels and a decrease in total protein and albumin were observed in accordance with allergy severity. In an endoscopic examination, inflammatory findings were confirmed in large areas of the colonic mucosa in case of higher severity levels, and infiltration of inflammatory cells other than eosinophils was found in the severest grade. Extensively hydrolyzed milk or amino acid-based milk was required for all patients with the severest grade. In addition, the timing of acquiring tolerance tended to be late for this grade. CONCLUSIONS: Classification and determination of the severity of non-IgE-GI-FAs in neonates and infants may not only contribute to elucidation of the pathogenesis but may also be useful in the clinical setting.

A Case of Intrathoracic Gastric Duplication Cyst Detected on Prenatal Ultrasound Examination.

A 37-year-old (G4P3) woman was referred to our hospital at 32 weeks of gestation for the evaluation of a fetus with an intrathoracic cystic lesion. Ultrasonography and magnetic resonance imaging revealed that a fetal cystic lesion without a mucosal layer was located in the posterior mediastinum. These findings were consistent with a bronchogenic cyst. At 38 3/7 weeks of gestation, an elective cesarean section was performed because of her previous cesarean section. A female neonate without any external anomalies, weighing 2,442 g, with Apgar scores of 8 and 9, and requiring no resuscitation was born. Four weeks after delivery, the neonate was admitted because of respiratory distress due to mass effect. At right lateral thoracotomy, a 105 × 65 mm of solitary smooth-walled cyst containing serosanguineous fluid was found in the posterior mediastinum, which was excised completely. Histologic examination revealed the diagnosis of the mediastinal gastric duplication cyst. The neonate made an uneventful recovery. Accurate diagnosis is not necessary, but detection and continuous observation are logical. Although gastric duplication, particularly intrathoracic, is a rare pathology, it should be considered in the differential diagnosis of any intrathoracic cyst.

Suppression of MUC5AC expression in human bronchial epithelial cells by interferon-γ.

BACKGROUND: Excessive mucin secretion in the airway is an important feature of airway inflammatory diseases. MUC5AC expression is regulated by a variety of stimuli such as cytokines. Little is known about the role of interferon (IFN)-γ in MUC5AC expression in human bronchial epithelial cells. METHODS: Human pulmonary mucoepidermoid carcinoma cell line (NCI-H292) and normal human bronchial epithelial (NHBE) cells were used to assess the effects of IFN-γ on MUC5AC transcription. RESULTS: Transforming growth factor (TGF)-α and double-stranded RNA (polyI:C)-induced MUC5AC mRNA and protein expression was repressed by IFN-γ in a concentration-dependent manner. IFN-γ showed limited effects on TGF-α and polyI:C-induced activation of epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase (ERK). A chromatin immunoprecipitation assay indicated that Sp1 bound to its cognate sequence located on the MUC5AC promoter. The Sp1 inhibitor mithramycin A inhibited MUC5AC mRNA expression, implying a critical role for Sp1 in MUC5AC induction. Importantly, IFN-γ impeded Sp1 binding to the MUC5AC promoter. CONCLUSIONS: These results suggest that IFN-γ represses MUC5AC expression, disturbing binding of Sp1 to its target sequences.

Reference values for Japanese children's respiratory resistance using the LMS method.

BACKGROUND: The forced oscillation technique (FOT) is useful for studying pulmonary function in children, as well as in school children with asthma. However, the standard values for respiratory resistance (Rrs) in Asian school children remain unknown. We evaluated the standard Rrs using a type of FOT, impulse oscillometry (IOS), in healthy Japanese children at elementary and junior high schools. METHODS: A total of 795 children (age range: 6-15 years; mean age ± SD: 11.1 ± 2.4 years; 404 boys, 391 girls) at elementary and junior high schools participated in the study. Of the 795 children, we evaluated the Rrs of 537 children aged 6-15 years (mean ± SD: 10.8 ± 2.4 years) using IOS. RESULTS: Regression analyses with three IOS parameters, Rrs at 5Hz (R5), Rrs at 20Hz (R20), and Rrs difference between 5Hz and 20Hz (R5-R20), for age, height, weight, and degree of obesity as independent variables demonstrated the strongest correlation between each parameter and children's height. All parameters decreased with increasing height. Using the lambda-mu-sigma (LMS) method, we created standard curves for the Rrs values based on height. CONCLUSIONS: Our standard curves could be useful for diagnosis and control evaluation of childhood asthma.

[A case of apple allergy with initial symptoms like food-dependent exercise-induced anaphylaxis].

A 13-year-old boy with two episodes of anaphylaxis after exercise was suspected as food-dependent exercise-induced anaphylaxis (FEIAn). The exercise challenge test after ingestion of an apple was performed, because apple was commonly contained in meals before the both episodes and a prick test for apple was positive. The exercise test was positive accompanied with nasal discharge, sneezing, throat discomfort, swelling of the uvula. The patient was instructed to refrain from exercise for 4 hours after ingestion of apple. In five months, he developed allergic symptoms only by an intake of foods containing heated apple without exercise and showed a slight increase in apple-specific IgE from negative to 0.51 IU/ml. The prognosis of FEIAn has not been well described. Cases with FEIAn to apples like this case require a close follow-up in consideration of development of allergic reactions without exercise.