A review on the pathophysiology of asthma remission

House dust mite-induced asthma exacerbates Alzheimer's disease changes in the brain of the AppNL-G-F mouse model of disease

Alzheimer's disease (AD) is an age-related neurodegenerative disorder characterized by the accumulation of amyloid-β (Aβ) plaques, neuroinflammation, and neuronal death. Besides aging, various comorbidities increase the risk of AD, including obesity, diabetes, and allergic asthma. Epidemiological studies have reported a 2.17-fold higher risk of dementia in asthmatic patients. However, the molecular mechanism(s) underlying this asthma-associated AD exacerbation is unknown. This study was designed to explore house dust mite (HDM)-induced asthma effects on AD-related brain changes using the AppNL-G-F transgenic mouse model of disease. Male and female 8-9 months old C57BL/6J wild type and AppNL-G-F mice were exposed to no treatment, saline sham, or HDM extract every alternate day for 16 weeks for comparison across genotypes and treatment. Mice were euthanized at the end of the experiment, and broncho-alveolar lavage fluid (BALF), blood, lungs, and brains were collected. BALF was used to quantify immune cell phenotype, cytokine levels, total protein content, lactate dehydrogenase (LDH) activity, and total IgE. Lungs were sectioned and stained with hematoxylin and eosin, Alcian blue, and Masson's trichrome. Serum levels of cytokines and soluble Aβ1-40/42 were quantified. Brains were sectioned and immunostained for Aβ, GFAP, CD68, and collagen IV. Finally, frozen hippocampi and temporal cortices were used to perform Aβ ELISAs and cytokine arrays, respectively. HDM exposure led to increased levels of inflammatory cells, cytokines, total protein content, LDH activity, and total IgE in the BALF, as well as increased pulmonary mucus and collagen staining in both sexes and genotypes. Levels of serum cytokines increased in all HDM-exposed groups. Serum from the AppNL-G-F HDM-induced asthma group also had significantly increased soluble Aβ1-42 levels in both sexes. In agreement with this peripheral change, hippocampi from asthma-induced male and female AppNL-G-F mice demonstrated elevated Aβ plaque load and increased soluble Aβ 1-40/42 and insoluble Aβ 1-40 levels. HDM exposure also increased astrogliosis and microgliosis in both sexes of AppNL-G-F mice, as indicated by GFAP and CD68 immunoreactivity, respectively. Additionally, HDM exposure elevated cortical levels of several cytokines in both sexes and genotypes. Finally, HDM-exposed groups also showed a disturbed blood-brain-barrier (BBB) integrity in the hippocampus of AppNL-G-F mice, as indicated by decreased collagen IV immunoreactivity. HDM exposure was responsible for an asthma-like condition in the lungs that exacerbated Aβ pathology, astrogliosis, microgliosis, and cytokine changes in the brains of male and female AppNL-G-F mice that correlated with reduced BBB integrity. Defining mechanisms of asthma effects on the brain may identify novel therapeutic targets for asthma and AD.

Clinical remission in severe asthma: lights and shadows on an ambitious goal

PURPOSE OF REVIEW

The aim of this study was Describe the latest evidence related to the concept of clinical remission in patients with severe asthma, focusing on the lights and shadows of this concept.

RECENT FINDINGS

The idea of clinical remission in severe asthma patients brings about a significant shift in the way asthma is treated and managed. Although there has yet to be unanimous agreement among various scientific societies on the precise definition, this concept can be extremely useful in advancing the treatment of the disease.

SUMMARY

Asthma is a common respiratory condition that affects more than 300 million people globally. It has variable symptoms and severity levels, with about 10% of patients experiencing severe asthma. While there have been advancements in treatment, severe asthma poses significant challenges. Recent approaches have focused on achieving clinical remission, which goes beyond symptom control to address underlying inflammation and biological processes. Clinical remission criteria include the absence of symptoms, reduced medication usage, and normalized inflammatory markers. Various biologic therapies show promise, with some patients achieving remission. However, remission's definition varies globally, hindering standardization and a valid comparison. Standardizing remission criteria and refining predictive factors are crucial for effective asthma management. Overall, achieving clinical remission offers hope for improved long-term outcomes in severe asthma patients.

SANI clinical remission definition: a useful tool in severe asthma management

In the field of severe asthma, the concept of disease control has recently been integrated by the one of clinical remission. With this new concept, we move on to analyze the efficacy of therapy on multiple parameters simultaneously, starting with the mandatory discontinuation of the systemic glucocorticoids, to which is added the effect on exacerbations, respiratory function, and symptoms control. The Italian severe asthma registry SANI (Severe Asthma Network Italy) drafted criteria for the definition of disease remission, allowing patients to be classified into two groups, partial and complete remission. The greater dynamism of the definition, provided by SANI, allows us to hypothesize its practical use, concerning therapy management of severe asthma patients, starting from the level of remission, with the aim to facilitate the clinical decision on replacement, continuation or modulation of patients' therapy.

An Updated Comprehensive Review of Plants and Herbal Compounds with Antiasthmatic Effect

Background

Asthma is a common disease with rising prevalence worldwide, especially in industrialized countries. Current asthma therapy with traditional medicines lacks satisfactory success, hence the patients' search for alternative and complementary treatments for their diseases. Researchers have conducted many studies on plants with antiallergic and antiasthmatic effects in recent decades. Many of these plants are now used in clinics, and searching for their mechanism of action may result in creating new ideas for producing more effective drugs.

Purpose

The goal of this review was to provide a compilation of the findings on plants and their active agents with experimentally confirmed antiasthmatic effects. Study Design and Method. A literature search was conducted from 1986 to November 2023 in Scopus, Springer Link, EMBASE, Science Direct, PubMed, Google Scholar, and Web of Science to identify and report the accumulated knowledge on herbs and their compounds that may be effective in asthma treatment.

Results

The results revealed that 58 plants and 32 herbal extracted compounds had antiasthmatic activity. Also, 32 plants were shown to have anti-inflammatory and antioxidative effects or may act as bronchodilators and potentially have antiasthmatic effects, which must be investigated in future studies.

Conclusion

The ability of herbal medicine to improve asthma symptoms has been confirmed by clinical and preclinical studies, and such compounds may be used as a source for developing new antiasthmatic drugs. Moreover, this review suggests that many bioactive compounds have therapeutic potential against asthma.

Correlation between LTC4S -444 A>C polymorphism and susceptibility to asthma: A meta-analysis and trial sequential analysis

Background

This study aims to uncover the potential correlation between LTC4S -444 A>C polymorphism and susceptibility to asthma.

Methods

Literatures reporting the correlation between LTC4S -444 A>C polymorphism and susceptibility to asthma published before 1st June, 2019 were searched in PubMed, Embase, Cochrane, Wanfang and CNKI. Eligible literatures were enrolled and their data were extracted. OR and its 95% CI were calculated for assessing the correlation between LTC4S -444 A>C polymorphism and susceptibility to asthma. The included data were weighted by an inverse variance and then analyzed by a fixed or random effects model. Heterogeneity test and sensitivity analysis were performed on the enrolled reports. STATA12.1 and TSA (trial sequential analysis) were utilized for analyses.

Based on what parameters is safe to discontinuate inhaled corticosteroids in children with asthma?

OBJECTIVE

Remission of childhood asthma has not been widely studied. Patients in clinical remission continue to have some degree of bronchial hyperresponsiveness (BHR). The aim of this study was to investigate whether clinical parameters and lung function test are good parameters for discontinuation of inhaled corticosteroids (ICS) in asthmatic children, including patients with persistent BHR, as measured by the methacholine challenge test (MCT).

METHODS

One year after discontinuation of inhaled corticosteroids (ICS), MCT was performed in a group of 40 asthmatic children to confirm or exclude BHR. In all patients, ICS treatment was discontinued based on the same parameters: symptoms, spirometry, daily PEF, and negative bronchodilator test. After achieving complete asthma control for at least 6 to 12 months, ICS treatment was stepped down and discontinued. Clinical course and spirometry were followed up after ICS discontinuation.

RESULTS

Positive MCT was found in 50% of the patients. There was no statistically significant difference between the positive and negative MCT groups in age at initiation and discontinuation of ICS therapy, duration of ICS therapy, duration of stepping down period, FEV1, and PEF at the time of withdrawal of ICS and one year later. ICS treatment had to be restarted in two patients from the positive MCT group, due to recurrence of asthma symptoms.

CONCLUSION

Clinical parameters, normal spirometry, daily PEF values, and a negative bronchodilator test are good parameters for discontinuing ICS treatment in asthmatic children, even in patients with persistent BHR. Children should continue to be monitored, as symptoms may recur.

Severe Asthma Network Italy Definition of Clinical Remission in Severe Asthma: A Delphi Consensus

Severe asthma affects about 10% of the population with asthma and is characterized by low lung function and a high count of blood leukocytes, mainly eosinophils. Various definitions are used in clinical practice and in the literature to identify asthma remission: clinical remission, inflammatory remission, and complete remission. This work highlights a consensus for asthma remission using a Delphi method. In the context of the Severe Asthma Network Italy, which accounts for 57 severe asthma centers and more than 2,200 patients, a board of six experts drafted a list of candidate statements in a questionnaire, which has been revised to minimize redundancies and ensure clear and consistent wording for the first round (R1) of the analysis. Thirty-two statements were included in the R1 questionnaire and then submitted to a panel of 80 experts, which used a 5-point Likert scale to measure agreement regarding each statement. Then, an interim analysis of R1 data was performed, and items were discussed and considered to produce a consistent questionnaire for round 2 (R2) of the analysis. Then, the board set the R2 questionnaire, which included only important topics. Panelists were asked to vote on the statements in the R2 questionnaire afterward. During R2, the criteria of complete clinical remission (the absence of the need for oral corticosteroids, symptoms, exacerbations or attacks, and pulmonary function stability) and those of partial clinical remission (the absence of the need for oral corticosteroids, and two of three criteria: the absence of symptoms, exacerbations or attacks, and pulmonary stability) were confirmed. This Severe Asthma Network Italy Delphi analysis defined a valuable and independent tool that is easy to use, to test the efficacy of different treatments in patients with severe asthma enrolled into the SANI registry.

Mulberroside F improves airway hyperresponsiveness and inflammation in asthmatic mice

Mulberroside F is isolated from the leaves and roots of Morus alba L. Here, we investigated whether mulberroside F could alleviate airway inflammation and eosinophil infiltration in the lungs of asthmatic mice. We also examined whether mulberroside F attenuated inflammatory responses in human tracheal epithelial BEAS-2B cells. Female BALB/c mice were sensitized and challenged with ovalbumin (OVA), and administered different doses of mulberroside F via intraperitoneal injection. Additionally, tumor necrosis factor (TNF)-α-stimulated BEAS-2B cells were treated with various doses of mulberroside F, followed by detection of the expressions of inflammatory cytokines and chemokines. The results demonstrated that mulberroside F mitigated the levels of proinflammatory cytokines and chemokines, and CCL11, in inflammatory BEAS-2B cells. Mulberroside F also suppressed reactive oxygen species (ROS) production and ICAM-1 expression in TNF-α-stimulated BEAS-2B cells, which effectively suppressed monocyte cell adherence. In an animal model of asthma, mulberroside F treatment attenuated airway hyperresponsiveness, eosinophil infiltration, and goblet cell hyperplasia. Mulberroside F treatment also decreased lung fibrosis and airway inflammation in OVA-sensitized mice. Moreover, mulberroside F significantly reduced expressions of Th2-associated cytokines (including interleukin(IL)-4, IL-5, and IL-13) in bronchoalveolar lavage fluid compared to OVA-sensitized mice. Our results confirmed that mulberroside F is a novel bioactive compound that can effectively reduce airway inflammation and eosinophil infiltration in asthmatic mice via inhibition of Th2-cell activation.

Why Current Therapy Does Not Cure Asthma. Is It Time to Move Towards a One Health Approach?

Asthma continues to be a disease for which there is no cure, even if it can be very well controlled with the appropriate therapies, which take into account the specific phenotype. The paradox of asthma is that asthma can heal spontaneously, albeit in a small percentage of cases. This observation is highly relevant, since understanding the mechanisms of spontaneous healing can pave the way for new strategies for treating asthma. It is likely that the lack of cure for asthma is due to the fact that current therapies target downstream mediators of the inflammatory response. Asthma can be considered a response of maladaptation of the airway epithelium to the environment, through the orientation of the innate immunity towards an inflammatory response. The important effect of the environment on asthma progress comes from interventions which help children who live in disadvantaged urban neighborhoods move to higher resourced neighborhoods. It is quite interesting that the magnitude of decrease of exacerbations associated with moving was larger than the effect of inhaled corticosteroids and similar to that observed for the effect of biologic agents. Alpine altitude climate treatment is a natural treatment that targets biological pathway, improving various outcomes such as asthma control and quality of life, exacerbation rate and hospitalizations. If as researchers we want to set ourselves the goal of achieving complete remission of asthma, without the need for ongoing maintenance treatment, we need to change the approach to finding new asthma treatment strategies. The One Health approach, an interdisciplinary strategy with focal point on human, animal, and environmental health interconnections, appears to be the right tool for researching asthma prevention and treatment.

Providing quality employment services to people living with asthma in the vocational rehabilitation program: A model for meeting the needs of an emerging clientele

BACKGROUND

With incidence and prevalence rates of asthma diagnoses steadily increasing in the United States and worldwide over the past 30 years, people with asthma are an emerging vocational rehabilitation (VR) consumer population.

OBJECTIVE

This article describes the job acquisition and return to work considerations facing employees with asthma.

METHOD

Following an overview of the etiology, incidence, prevalence, and career development implications of this chronic respiratory disease, the authors present career preparatory and return to work recommendations to meet the needs of Americans with asthma across the phases of the VR process.

RESULTS

The importance of access to quality healthcare, lifestyle and environmental modifications to promote respiratory health, employer consultation, workplace accommodations and universal design, and interface with medical and mental health professionals is emphasized throughout the article.

CONCLUSION

Asthma is an emerging disability that disproportionally affects people of color and people who live in poverty. Rehabilitation professionals must be prepared to meet the needs of this growing and diverse clientele as people with asthma seek assistance from the VR program in acquiring, maintaining, and advancing in meaningful, satisfying employment.

Association between Asthma and Oral Health Symptoms in Adolescents

Oral health is an indicator of patients' overall quality of life. Poor oral health among adolescents with asthma can affect their health in adulthood. This study researched the association between asthma and oral health symptoms in South Korean adolescents. Data from the 2020 Korea Youth Risk Behavior Web-based Survey were used. A total of 44,940 students participated in this study. The dependent variables were self-reported oral health symptoms. Asthma was the primary independent variable based on diagnosis in the past 12 months. The chi-squared test and multivariable logistic regression analysis were used. Students with asthma were associated with oral health symptoms, compared with those without asthma (boys, odds ratio (OR): 1.29, 95% confidence interval (CI) = 1.01-1.66; girls, OR: 1.94, 95% CI = 1.40-2.69). Poor health habits, such as low physical activity, higher sweetened beverage consumption, and fewer sleeping hours, were associated with oral health symptoms. Students who did not receive asthma treatment also had higher oral health symptoms (boys, OR: 1.29, 95% CI = 1.13-1.48, girls, OR: 1.34, 95% CI = 1.15-1.57). Students with absence due to asthma had a higher risk of oral health than those without asthma (boys, OR: 1.31, 95% CI = 1.17-1.46, girls OR: 1.28, 95% CI = 1.12-1.46). Students with asthma had a high risk of poor oral health among South Korean adolescents, suggesting more attention be given to regular dental check-ups and maintaining oral hygiene.

Defining response to therapy with biologics in severe asthma: from global evaluation to super response and remission

INTRODUCTION

In recent years, monoclonal antibodies targeting Type-2 inflammatory pathways have been developed for severe asthma treatment. However, even when patients are carefully selected, the response to treatment varies.

AREAS COVERED

Different studies have evaluated response to therapy with biologics such as exacerbation reduction, symptom improvement, pulmonary function increase, improvement in QoL, or decrease of oral corticosteroids, showing that all patients do not respond to all disease aspects and leading to an extensive debate regarding the definition of response.

EXPERT OPINION

Assessing response to therapy is of great importance, but since there is no uniform definition of treatment response, the recognition of patients who really benefit from these therapies remains an unmet need. In the same context, identifying non-responding patients in which biologic therapy should be switched or substituted by alternative treatment options is of paramount importance. In this review, we present the road trip of the definition of therapeutic response to biologics in severe asthmatics by presenting the current relevant medical literature. We also present the suggested predictors of response, with an emphasis on the so-called super-responders. Finally, we discuss the recent insights regarding asthma remission as a feasible treatment goal and provide a simple algorithm for the evaluation of response.

Sulfur dioxide-enhanced asthma susceptibility is involved with inhibition of bitter taste transduction in mouse lung

Sulfur dioxide (SO₂) may induce asthma-like symptoms or worsen existing asthma, but the underlying mechanism is still unclear. In this study, the relationship between SO₂ exposure, asthma development, and bitter taste transduction was analyzed using ovalbumin (OVA)-induced and SO₂-aggravated asthma models. The results showed that twenty-seven and twelve bitter taste receptors (Tas2rs) were detectable in mouse trachea and lung, respectively, and that all of them were nearly down-regulated in OVA-induced BALB/c and C57BL/6 asthmatic mice. SO₂ exposure alone did not trigger a distinct asthma-like phenotype, but the combination of SO₂ and OVA allergen caused more severe asthma symptoms in mice including enhanced inflammatory cells infiltration, thickened airway walls, increased mucus secretion, and elevated expression of proinflammatory and Th2 cytokines (TNF-α, IL-4, IL-5, IL-13). Furthermore, SO₂ enhanced the transcriptional repression of Tas2rs in OVA-induced asthmatic mice. These results indicated that the occurrence of mice asthma was correlated with the inhibition of bitter taste transduction, and more severe airway inflammation and injury were accompanied with an enhanced inhibition of bitter taste transduction. Our findings suggest that SO₂ inhalation may amplify Th2 inflammatory responses in the lung of asthmatic mice by inhibiting bitter taste transduction, and thereby exacerbate asthma symptoms.

Effect of the COVID-19 Lockdown on Asthma Biological Rhythms

Asthma has a striking temporal character, in which time-of-day, patient age, and season each influence disease activity. The extent to which rhythms in asthma activity reflect exposure to specific disease triggers remains unclear. In this study, we examined how virus mitigation strategies enacted during the COVID-19 pandemic ("lockdown measures") affected rhythms in asthma clinical activity in children. To this end, we retrospectively analyzed asthma clinical presentations in children aged <18 years to our regional academic medical center, comparing 4 years of medical records prior to COVID-19 lockdown measures with the 12 months immediately after the institution of such measures. We correlated these data to positive viral test results, febrile seizures, and allergic clinical surrogates (allergic reaction visits and Emergency Department [ED] antihistamine prescriptions, respectively) over the same time frame. In the 12 months following the institution of the COVID-19 lockdown, positivity rates for common respiratory viruses dropped by 70.2% and ED visits for asthma among children dropped by 62% compared to pre-COVID years. Lockdown suppressed seasonal variation in positive viral tests and asthma ED visits, while diurnal rhythms in asthma visits were unchanged. Asthma seasonality correlated most strongly with rhinovirus positivity both before and after the institution of COVID lockdown measures. Altogether, our data support a causal role for viruses in driving seasonal variability in asthma exacerbations in children.

Age-Dependent Reduction in Asthmatic Pathology through Reprogramming of Postviral Inflammatory Responses

Asthma is a chronic disease of childhood, but for unknown reasons, disease activity sometimes subsides as children mature. In this study, we present clinical and animal model evidence suggesting that the age dependency of childhood asthma stems from an evolving host response to respiratory viral infection. Using clinical data, we show that societal suppression of respiratory virus transmission during coronavirus disease 2019 lockdown disrupted the traditional age gradient in pediatric asthma exacerbations, connecting the phenomenon of asthma remission to virus exposure. In mice, we show that asthmatic lung pathology triggered by Sendai virus (SeV) or influenza A virus is highly age-sensitive: robust in juvenile mice (4-6 wk old) but attenuated in mature mice (>3 mo old). Interestingly, allergen induction of the same asthmatic traits was less dependent on chronological age than viruses. Age-specific responses to SeV included a juvenile bias toward type 2 airway inflammation that emerged early in infection, whereas mature mice exhibited a more restricted bronchiolar distribution of infection that produced a distinct type 2 low inflammatory cytokine profile. In the basal state, aging produced changes to lung leukocyte burden, including the number and transcriptional landscape of alveolar macrophages (AMs). Importantly, depleting AMs in mature mice restored post-SeV pathology to juvenile levels. Thus, aging influences chronic outcomes of respiratory viral infection through regulation of the AM compartment and type 2 inflammatory responses to viruses. Our data provide insight into how asthma remission might develop in children.

Natural history and associated early life factors of childhood asthma: a population registry-based cohort study in Denmark

OBJECTIVE

Asthma is a common chronic disease that imposes a substantial burden on individuals and society. However, the natural history of childhood asthma in a large population remained to be studied. This study aimed to describe the natural course of childhood asthma and examine the association between early life factors and childhood asthma.

DESIGN

A population-based cohort study.

SETTING

This study was based on the national registry data in Denmark.

PARTICIPANTS

All liveborn singletons in Denmark during 1995-1997 were identified and followed them till the end of 2009. Finally, 193 673 children were eligible for our study.

EXPOSURES

The following characteristics were examined as potential early life factors associated with childhood asthma, including parity, maternal asthma history, maternal smoking during pregnancy, maternal social status, delivery method and gender.

MAIN OUTCOMES AND MEASURES

Asthma cases were identified on the basis of hospitalisation for asthma and prescriptions for antiasthmatic medications. Asthma remission was defined as no hospitalisation or prescription recorded for 2 years. Cox proportional hazards' regression and logistic regression were used to evaluate the association between early life factors and the occurrence and remission of childhood asthma.

RESULTS

The cumulative occurrence rate of asthma in children aged 3-14 years was 13.3% and the remission rate was 44.1%. The occurrence rate decreased with age. Being female had a lower risk of asthma (HR: 0.72, 95% CI 0.70 to 0.74) and higher remission rate of asthma (HR: 1.18, 1.13 to 1.22), while maternal asthma was associated with a higher risk of asthma (HR: 2.15, 2.04 to 2.26) and decreased remission rate of asthma (HR: 0.79, 0.73 to 0.85). These patterns remained the same for early onset asthma.

CONCLUSIONS

Female gender had a lower risk of asthma and a better chance of remission, while maternal asthma history had an opposite effect. The early life factors may influence the natural course of childhood asthma.

Accelerated decline in lung function in adults with a history of remitted childhood asthma

AIM

A significant number of children with asthma show remission in adulthood. Although these adults are often diagnosed with chronic obstructive pulmonary disease in later life, the effect of clinically remitted childhood asthma on the decline in lung function during adulthood is uncertain. We examined whether clinical remission of childhood asthma was associated with an accelerated decline in lung function in apparently non-asthmatic adults.

METHODS

Here, 3584 participants (mean age, 48.1 years; range, 35-65 years) who did not have adulthood asthma and other lung diseases and had normal lung function at the baseline visit were included. They were categorised as follows: those with remitted childhood asthma (n=121) and healthy controls (n=3463) according to their self-reported childhood asthma history. Spirometry was performed at baseline and follow-up visits.

RESULTS

The mean follow-up time was 5.3 years. Multivariate regression analysis showed that remitted childhood asthma and smoking were independently associated with a rapid decline in forced expiratory volume in 1 s (FEV₁) and forced vital capacity (FVC). Besides, smoking was an independent predictor of a rapid decline in the FEV₁/FVC. The annual decline in FEV₁ and FVC was significantly greater in participants with remitted childhood asthma than in healthy controls, and the differences remained significant after adjusting for the propensity score.

CONCLUSION

A history of clinically remitted childhood asthma is an independent risk factor for accelerated decline in lung function in adults. Remitted childhood asthma and smoking may additively accelerate the development of obstructive lung disease.

Genetic deletion of the Tas2r143/Tas2r135/Tas2r126 cluster reveals that TAS2Rs may not mediate bitter tastant-induced bronchodilation

Bitter taste receptors (TAS2Rs) and their signaling elements are detected throughout the body, and bitter tastants induce a wide variety of biological responses in tissues and organs outside the mouth. However, the roles of TAS2Rs in these responses remain to be tested and established genetically. Here, we employed the CRISPR/Cas9 gene-editing technique to delete three bitter taste receptors-Tas2r143/Tas2r135/Tas2r126 (i.e., Tas2r triple knockout [TKO]) in mice. The fidelity and effectiveness of the Tas2r deletions were validated genetically at DNA and messenger RNA levels and functionally based on the tasting of TAS2R135 and TAS2R126 agonists. Bitter tastants are known to relax airways completely. However, TAS2R135 or TAS2R126 agonists either failed to induce relaxation of pre-contracted airways in wild-type mice and Tas2r TKO mice or relaxed them dose-dependently, but to the same extent in both types of mice. These results indicate that TAS2Rs are not required for bitter tastant-induced bronchodilation. The Tas2r TKO mice also provide a valuable model to resolve whether TAS2Rs mediate bitter tastant-induced responses in many other extraoral tissues.

Asthma Remission Disparities Among US Youth by Sexual Identity and Race/Ethnicity, 2009-2017

BACKGROUND

Sexual minority and racial/ethnic minority youth experience a higher burden of asthma. The frameworks of minority stress theory and intersectionality suggest that sexual minority and racial/ethnic minority youth may experience disparities in nonremitting asthma.

OBJECTIVE

To examine adjusted odds of nonremitting asthma by sexual identity, race/ethnicity, and their intersections, along with their relationship with traditional nonremitting asthma risk factors (weight status and smoking) and victimization (bullying, cyberbullying, and forced sex).

METHODS

We used data from the Youth Risk Behavior Survey pooled across 41 jurisdiction-years (biennially, 2009-2017), resulting in a sample of 21,789 US youth. The prevalence of nonremitting asthma was examined by sexual identity, race/ethnicity, and their intersections, stratified by sex. Bivariate associations and backward logistic regression models, stratified by sex, were built to examine nonremitting asthma disparities and the effects of selected traditional correlates and victimization variables.

RESULTS

At the intersections, 8 sexual minority and racial/ethnic minority subpopulations were significantly more likely to have nonremitting asthma compared with White heterosexual sex-matched peers. White gay males and Black lesbian females had the highest odds of nonremitting asthma. Traditional risks of nonremitting asthma and victimization were associated with attenuated odds of nonremitting asthma.

CONCLUSIONS

Many sexual minority and racial/ethnic youth subpopulations are more likely to have nonremitting asthma. Evidence suggests that traditional nonremitting asthma risk factors and victimization may partly explain disparities in nonremitting asthma. Asthma management guidelines should be updated to include population health disparities of sexual and racial/ethnic minorities.

Long noncoding RNA LINC-PINT retards the abnormal growth of airway smooth muscle cells via regulating the microRNA-26a-5p/PTEN axis in asthma

BACKGROUND

Asthma is a chronic respiratory disease worldwide. This study aimed to explore the functions of the long noncoding RNA LINC-PINT (LINC-PINT) in asthma and to determine its underlying molecular mechanisms.

METHODS

Rat asthma model was established with ovalbumin sensitization and challenge. The serum level of IgE, airway hyperresponsiveness (AHR), airway inflammation, and pathological changes of lung were evaluated. Airway smooth muscle cells (ASMCs) were stimulated with platelet-derived growth factor-BB (PDGF-BB) to mimic the asthma-like condition at cellular level. QRT-PCR was performed to detect the expression of LINC-PINT, microRNA-26a-5p (miR-26a-5p), and PTEN. MTT and transwell assays were performed to measure the viability and migration of ASMCs. The protein expression of airway remodelling marker MMP-1 and MMP-9 was measured by western blot. The interactions among LINC-PINT, miR-26a-5p, and PTEN were determined by dual-luciferase reporter assay.

RESULTS

The expression of LINC-PINT and PTEN was decreased, while miR-26a-5p expression was increased in PDGF-BB-stimulated ASMCs. In vivo, overexpression of LINC-PINT decreased the serum level of IgE, AHR, airway inflammation, and pathological changes of lung in asthma rat model. In vitro, up-regulation of LINC-PINT decreased the viability, migration, and MMP-1 and MMP-9 protein expression in PDGF-BB-stimulated ASMCs. Dual-luciferase reporter assay determined that LINC-PINT targeted miR-26a-5p, and miR-26a-5p targeted PTEN in ASMCs. Feedback approaches confirmed that miR-26a-5p up-regulation or PTEN down-regulation reversed the suppressive effect of LINC-PINT overexpression on the abnormal growth of ASMCs.

CONCLUSIONS

LINC-PINT overexpression retarded the abnormal growth of ASMCs by regulating the miR-26a-5p/PTEN axis, offering a potential therapeutic target for asthma.

Childhood asthma and cardiovascular morbidity and mortality in adulthood: The Busselton Health Study

BACKGROUND

Long-term childhood asthma studies that investigate adult outcomes other than respiratory morbidity are lacking. This study examines the associations of childhood asthma and the occurrence of cardiovascular disease (CVD) events and mortality in adulthood.

METHODS

A cohort of 4430 school children (aged 17 years) who attended the Busselton Health Study between 1967 and 1983 were analyzed. Self-reported history of doctor-diagnosed asthma was determined based on the questionnaire. Subsequent CVD events (hospital admissions or death) up to 2014 were identified using the Western Australia Data Linkage System. Cox regression models were used to investigate the impact of childhood asthma on CVD events and mortality in adulthood. A subgroup of 2153 participants who re-attended a survey in young adulthood was also analyzed.

RESULTS

A total of 462 (10%) of the cohort had childhood asthma. During follow-up, 867 participants experienced a CVD event and 22 participants died from CVD. Childhood asthma was not associated with the risk of CVD events in adulthood (HR, 1.12; 95% CI: 0.91-1.39; p = .2833) and this persisted after adjustment for confounders. Childhood asthma was not associated with coronary heart disease events (HR, 0.72; 95% CI: 0.40-1.30; p = .2761), heart failure events (HR, 0.55; 95% CI: 0.07-4.13; p = .5604) or CVD mortality (HR, 0.91; 95% CI: 0.21-3.89; p = .8987) in adulthood.

CONCLUSION

Childhood asthma is not associated with the risk of CVD events and mortality in adulthood.

iTRAQ-Based Proteomics Reveals Gu-Ben-Fang-Xiao Decoction Alleviates Airway Remodeling via Reducing Extracellular Matrix Deposition in a Murine Model of Chronic Remission Asthma

Airway remodeling is a primary pathological feature of asthma. The current therapy for asthma mainly targets reducing inflammation but not particularly airway remodeling. Therefore, it is worthwhile to develop alternative and more effective therapies to attenuate remodeling. Gu-Ben-Fang-Xiao Decoction (GBFXD) has been used to effectively and safely treat asthma for decades. In this study, GBFXD regulated airway inflammation, collagen deposition, and the molecules relevant to airway remodeling such as Vimentin, α-SMA, hydroxyproline, and E-cadherin in chronic remission asthma (CRA) murine model. Proteomic analysis indicated that the overlapping differentially expressed proteins (DEPs) (Model/Control and GBFXD/Model) were mainly collagens and laminins, which were extracellular matrix (ECM) proteins. In addition, the KEGG analysis showed that GBFXD could regulate pathways related to airway remodeling including ECM-receptor interactions, focal adhesion, and the PI3K/AKT signaling pathway, which were the top three significantly enriched pathways containing the most DEPs for both Model/Control and GBFXD/Model. Further validation research showed that GBFXD regulated reticulon-4 (RTN4) and suppressed the activation of the PI3K/AKT pathway to alleviate ECM proteins deposition. In conclusion, our findings indicate that GBFXD possibly regulate the PI3K/AKT pathway via RTN4 to improve airway remodeling, which provides a new insight into the molecular mechanism of GBFXD for the treatment of CRA.

Fucoxanthin Ameliorates Oxidative Stress and Airway Inflammation in Tracheal Epithelial Cells and Asthmatic Mice

Fucoxanthin is isolated from brown algae and was previously reported to have multiple pharmacological effects, including anti-tumor and anti-obesity effects in mice. Fucoxanthin also decreases the levels of inflammatory cytokines in the bronchoalveolar lavage fluid (BALF) of asthmatic mice. The purpose of the present study was to investigate the effects of fucoxanthin on the oxidative and inflammatory responses in inflammatory human tracheal epithelial BEAS-2B cells and attenuated airway hyperresponsiveness (AHR), airway inflammation, and oxidative stress in asthmatic mice. Fucoxanthin significantly decreased monocyte cell adherence to BEAS-2B cells. In addition, fucoxanthin inhibited the production of pro-inflammatory cytokines, eotaxin, and reactive oxygen species in BEAS-2B cells. Ovalbumin (OVA)-sensitized mice were treated by intraperitoneal injections of fucoxanthin (10 mg/kg or 30 mg/kg), which significantly alleviated AHR, goblet cell hyperplasia and eosinophil infiltration in the lungs, and decreased Th2 cytokine production in the BALF. Furthermore, fucoxanthin significantly increased glutathione and superoxide dismutase levels and reduced malondialdehyde (MDA) levels in the lungs of asthmatic mice. These data demonstrate that fucoxanthin attenuates inflammation and oxidative stress in inflammatory tracheal epithelial cells and improves the pathological changes related to asthma in mice. Thus, fucoxanthin has therapeutic potential for improving asthma.

Gu-Ben-Fang-Xiao decoction modulates lipid metabolism by activating the AMPK pathway in asthma remission

Gu-Ben-Fang-Xiao decoction (GBFXD), derived from the traditional Chinese medicine Yu-Ping-Feng-San, is widely used in clinical settings and has obvious curative effects in respiratory diseases. GBFXD regulates cholesterol transport and lipid metabolism in chronic persistent asthma. There is evidence for its beneficial effects in the remission stage of asthma; however, its metabolic regulatory effects and underlying mechanisms during asthma remission are unclear. In the present study, we used liquid chromatography-mass spectrometry (LC-MS) to analyse the metabolic profile of mouse serum during asthma remission. The acquired LC-MS data were subjected to a multivariate analysis for identification of significantly altered metabolites. In total, 42 metabolites were significantly differentially expressed among the control, model, and GBFXD groups. In particular, levels of fatty acids, acylcarnitines, phosphatidylcholines, phosphatidylethanolamines, phosphatidylinositols, triglycerides, and diacylglycerols were altered during asthma remission. GBFXD may maintain lipid homeostasis on the lung surface by modulating lipid metabolism and may thereby alleviate asthma. We further quantified hypogeic acid (FA 16:1) based on targeted metabolomics and found that GBFXD may regulate fatty acid metabolism by activating the AMP-activated protein kinase (AMPK) pathway. These results support the use of GBFXD in patients with asthma remission.

Epigenome-wide association study identifies DNA methylation markers for asthma remission in whole blood and nasal epithelium

BACKGROUND

Asthma is a chronic respiratory disease which is not curable, yet some patients experience spontaneous remission. We hypothesized that epigenetic mechanisms may be involved in asthma remission.

METHODS

Clinical remission (ClinR) was defined as the absence of asthma symptoms and medication for at least 12 months, and complete remission (ComR) was defined as ClinR with normal lung function and absence of airway hyperresponsiveness. We analyzed differential DNA methylation of ClinR and ComR comparing to persistent asthma (PersA) in whole blood samples (n = 72) and nasal brushing samples (n = 97) in a longitudinal cohort of well characterized asthma patients. Significant findings of whole blood DNA methylation were tested for replication in two independent cohorts, Lifelines and Epidemiological study on the Genetics and Environment of Asthma (EGEA).

RESULTS

We identified differentially methylated CpG sites associated with ClinR (7 CpG sites) and ComR (129 CpG sites) in whole blood. One CpG (cg13378519, Chr1) associated with ClinR was replicated and annotated to PEX11 (Peroxisomal Biogenesis Factor 11 Beta). The whole blood DNA methylation levels of this CpG were also different between ClinR and healthy subjects. One ComR-associated CpG (cg24788483, Chr10) that annotated to TCF7L2 (Transcription Factor 7 Like 2) was replicated and associated with expression of TCF7L2 gene. One out of seven ClinR-associated CpG sites and 8 out of 129 ComR-associated CpG sites identified from whole blood samples showed nominal significance (P < 0.05) and the same direction of effect in nasal brushes.

CONCLUSION

We identified DNA methylation markers possibly associated with clinical and complete asthma remission in nasal brushes and whole blood, and two CpG sites identified from whole blood can be replicated in independent cohorts and may play a role in peroxisome proliferation and Wnt signaling pathway.

Interleukin 4 gene polymorphism (-589C/T) and the risk of asthma: a meta-analysis and met-regression based on 55 studies

BACKGROUND

Numerous investigations have previously evaluated the association of interleukin (IL) 4 gene polymorphisms and the risk of asthma, conferring inconsistent results. To resolve the incongruent outcomes yielded from different single studies, we conducted the most up-to-date meta-analysis of IL4 gene -589C/T (rs2243250) polymorphism and susceptibility to asthma.

METHODS

A systematic literature search was performed in ISI web of science, Scopus, Medline/PubMed databases prior to September 2020, and the pooled odds ratio (OR) and their corresponding 95% CI were calculated to determine the association strength.

RESULTS

Literature search led to retrieving of 49 publications (55 case-control studies) containing 9572 cases and 9881 controls. It was revealed that IL4 gene -589C/T polymorphism increased the risk of asthma across all genetic models, including dominant model (OR = 1.22), recessive model (OR = 1.17), allelic model (OR = 1.21), and TT vs. CC model (OR = 1.34), but not the CT vs. TT model. The subgroup analysis by age indicated that IL4 gene -589C/T polymorphism was significantly associated with asthma risk in both pediatrics and adults. Additionally, the subgroup analysis by ethnicity revealed significant association in Asian, American, and Europeans. Finally, subgroup analysis by East Asian and non-East Asian populations indicated significant associations.

CONCLUSIONS

The current meta-analysis revealed that IL4 gene -589C/T polymorphism was a susceptibility risk in both pediatrics and adults in the whole and different ethnic groups.

Drug nanodelivery systems based on natural polysaccharides against different diseases

Drug nanodelivery systems (DNDSs) are fascinated cargos to achieve outstanding therapeutic results of various drugs or natural bioactive compounds owing to their unique structures. The efficiency of several pharmaceutical drugs or natural bioactive ingredients is restricted because of their week bioavailability, poor bioaccessibility and pharmacokinetics after orally pathways. In order to handle such constraints, usage of native/natural polysaccharides (NPLS) in fabrication of DNDSs has gained more popularity in the arena of nanotechnology for controlled drug delivery to enhance safety, biocompatibility, better retention time, bioavailability, lower toxicity and enhanced permeability. The main commonly used NPLS in nanoencapsulation systems include chitosan, pectin, alginates, cellulose, starches, and gums recognized as potential materials for fabrication of cargos. Herein, this review is centered on different polysaccharide-based nanocarriers including nanoemulsions, nanohydrogels, nanoliposomes, nanoparticles and nanofibers, which have already served as encouraging candidates for entrapment of therapeutic drugs as well as for their sustained controlled release. Furthermore, the current article explicitly offers comprehensive details regarding application of NPLS-based nanocarriers encapsulating several drugs intended for the handling of numerous disorders, including diabetes, cancer, HIV, malaria, cardiovascular and respiratory as well as skin diseases.

Childhood asthma increases respiratory morbidity, but not all-cause mortality in adulthood: The Busselton Health Study

BACKGROUND

Long-term childhood asthma studies that investigate adult outcomes other than lung function are lacking. This study examines the associations of childhood asthma and the occurrence of respiratory events and all-cause mortality in adulthood.

METHODS

A cohort of 4430 school children (aged to 17 years) who attended the Busselton Health Study between 1967 and 1983 were analysed. Self-reported history of asthma was determined using questionnaires. Participants were followed until 2014 for respiratory disease-related events (hospital admissions or death) and all-cause mortality using the Western Australia Data Linkage System. Cox regression models were used to investigate the impact of childhood asthma on respiratory events and all-cause mortality in adulthood. A subgroup of 2153 participants who re-attended a survey in young adulthood was also analysed.

RESULTS

A total of 462 (10%) of the cohort had childhood asthma. During follow-up 791 participants experienced a respiratory event and 140 participants died. Childhood asthma was associated with an increased risk of respiratory events in adulthood (unadjusted HR 1.84, 95% CI 1.52 to 2.23; P < 0.0001). The result remained significant after adjusting for adult-onset asthma, FEV₁, body mass index, smoking, dusty job, hay fever, and respiratory symptoms (adjusted HR 1.68, 95% CI 1.07 to 2.64; P = 0.0247). Childhood asthma was not associated with all-cause mortality in adulthood (unadjusted HR 1.08, 95% CI 0.63 to 1.84; P = 0.7821).

CONCLUSION

Childhood asthma is associated with increased risk of respiratory disease-related hospital admissions and death but not all-cause mortality in adulthood.

ZDHXB-101 (3',5-Diallyl-2, 4'-dihydroxy-[1,1'-biphen-yl]-3,5'-dicarbaldehyde) protects against airway remodeling and hyperresponsiveness via inhibiting both the activation of the mitogen-activated protein kinase and the signal transducer and activator of transcription-3 signaling pathways

Airway remodeling consists of the structural changes of airway walls, which is often considered the result of longstanding airway inflammation, but it may be present to an equivalent degree in the airways of children with asthma, raising the need for early and specific therapeutic interventions. The arachidonic acid cytochrome P-450 (CYP) pathway has thus far received relatively little attention in its relation to asthma. In this study, we studied the inhibition of soluble epoxide hydrolase (sEH) on airway remodeling and hyperresponsiveness (AHR) in a chronic asthmatic model which long-term exposure to antigen over a period of 12 weeks. The expression of sEH and CYP2J2, the level of 14, 15-epoxyeicosatrienoic acids (EETs), airway remodeling, hyperresponsiveness and inflammation were analyzed to determine the inhibition of sEH. The intragastric administration of 3 or 10 mg/kg ZDHXB-101, which is a structural derivative of natural product honokiol and a novel soluble epoxide hydrolase (sEH) inhibitor, daily for 9 weeks significantly increased the level of 14, 15-EETs by inhibiting the expression of sEH and increasing the expression of CYP2J2 in lung tissues. ZDHXB-101 reduced the expression of remodeling-related markers such as interleukin (IL)-13, IL-17, MMP-9 N-cadherin, α-smooth muscle actin, S100A4, Twist, goblet cell metaplasia, and collagen deposition in the lung tissue or in bronchoalveolar lavage fluid. Moreover, ZDHXB-101 alleviated AHR, which is an indicator that is used to evaluate the airway remodeling function. The inhibitory effects of ZDHXB-101 were demonstrated to be related to its direct inhibition of the extracellular signal-regulated kinase (Erk1/2) phosphorylation, as well as inhibition of c-Jun N-terminal kinases (JNK) and the signal transducer and activator of transcription-3 (STAT3) signal transduction. These findings first revealed the anti-remodeling potential of ZDHXB-101 lead in chronic airway disease.

Inhibition of soluble epoxide hydrolase attenuates airway remodeling in a chronic asthma model

Airway remodeling in asthma is difficult to treat because of its complex pathophysiology that involves proinflammatory cytokines, as well as the arachidonic acid cytochrome P-450 (CYP) pathway; however, it has received little attention. In this study, we assessed the efficacy of a soluble epoxide hydrolase (sEH) on airway remodeling in a mouse model of chronic asthma. The expression of sEH and CYP2J2 and the level of 14,15-epoxyeicosatrienoic acid (14,15-EET), airway remodeling and hyperresponsiveness (AHR) were analyzed to determine the level of sEH inhibition. AUDA, a sEH inhibitor, was given daily for 9 weeks orally, which significantly increased the level of 14,15-EET by inhibiting the expression of sEH and increasing the expression of CYP2J2 in lung tissues. The inhibition of sEH reduced the expression of remodeling-related molecular markers, such as interleukin (IL)-13, IL-17, matrix metalloproteinase 9, N-cadherin, α-smooth muscle actin (α-SMA), S100A4, Twist, epithelial goblet cell metaplasia, and collagen deposition in bronchoalveolar lavage fluid (BAL fluid) and lung tissues. Moreover, remodeling-related eosinophil accumulation in the BAL fluid and infiltration into the lung tissue were improved by AUDA. Finally, AUDA alleviated AHR, which is a functional indicator of airway remodeling. The effect of AUDA on airway remodeling was related to the downregulation of extracellular-regulated protein kinases (Erk1/2), c-Jun N-terminal kinases (JNK) and signal transducer and activator of transcription 3 (STAT3). To our knowledge, this is the first report to demonstrate that inhibition of sEH exerts significant protective effects on airway remodeling in asthma.

Assessing small airways dysfunction in asthma, asthma remission and healthy controls using particles in exhaled air

Asthma is a chronic disease, characterised by variable airflow obstruction and airway inflammation [1]. Small airways are thought to be a major site of pathology in asthma [2, 3]. There are different tools to assess small airways dysfunction (SAD), such as spirometry, body plethysmography, impulse oscillometry (IOS), multiple-breath nitrogen washout (MBNW), alveolar fraction of exhaled nitric oxide (F_ENO) and gas trapping assessed by high-resolution computed tomography (CT). However, there is no golden standard and some tests are difficult to perform [2, 3].

PExA mass can distinguish asthmatics from healthy individuals. Subjects with complete, but not clinical, asthma remission exhale more PExA mass compared to asthma. Higher PExA mass was associated with better function of both the small and large airways.http://bit.ly/2znHABg