Passive smoking impairs histone deacetylase-2 in children with severe asthma

Impact of indoor environment on children's pulmonary health

INTRODUCTION

A child's living environment has a significant impact on their respiratory health, with exposure to poor indoor air quality (IAQ) contributing to potentially lifelong respiratory morbidity. These effects occur throughout childhood, from the antenatal period through to adolescence. Children are particularly susceptible to the effects of environmental insults, and children living in socioeconomic deprivation globally are more likely to breathe air both indoors and outdoors, which poses an acute and long-term risk to their health. Adult respiratory health is, at least in part, determined by exposures and respiratory system development in childhood, starting in utero.

AREAS COVERED

This narrative review will discuss, from a global perspective, what contributes to poor IAQ in the child's home and school environment and the impact that indoor air pollution exposure has on respiratory health throughout the different stages of childhood.

EXPERT OPINION

All children have the right to a living and educational environment without the threat of pollution affecting their health. Action is needed at multiple levels to address this pressing issue to improve lifelong respiratory health. Such action should incorporate a child's rights-based approach, empowering children, and their families, to have access to clean air to breathe in their living environment.

Endoplasmic reticulum stress impairs the immune regulation property of macrophages in asthmatic patients

The current study aims to characterize the counteraction of M2 cells in response to Endoplasmic reticulum (ER) stress. ER stress was detected in bronchoalveolar lavage fluids (BALF) Mϕs, which was at unresolved state in asthma patients. A positive correlation was detected between ER stress in Mϕs and lung functions/allergic mediators/Th2 cytokines in BALF or specific IgE in the serum. Levels of immune regulatory mediator in the BALF were negatively correlated to ER stress in BALF Mϕs. The ER stress state influenced the immune regulatory property of BALF Mϕ. Exposure to environmental pollutant, 3-metheyl-4-nitrophenol, exacerbated ER stress in Mϕ, which affected the Mϕ phenotyping. Exacerbation of ER stress suppressed the expression of IL-10 and programmed cell death protein-1 (PD-1) in Mϕs by increasing the expression of the ring finger protein 20 (Rnf20). Conditional inhibition of Rnf20 in Mϕs attenuated experimental airway allergy.

Aflatoxin B1 exposure induced developmental toxicity and inhibited muscle development in zebrafish embryos and larvae

The prevalence of aflatoxin B1 (AFB1), one of the most toxic mycotoxins that contaminates feedstock and food is increasing worldwide. AFB1 can cause various health problems in humans and animals, as well as direct embryotoxicity. However, the direct toxicity of AFB1 on embryonic development, especially foetal foetus muscle development, has not been studied in depth. In the present study, we used zebrafish embryos as a model to study the mechanism of the direct toxicity of AFB1 to the foetus, including muscle development and developmental toxicity. Our results showed that AFB1 caused motor dysfunction in zebrafish embryos. In addition, AFB1 induces abnormalities in muscle tissue architecture, which in turn causes abnormal muscle development in larvae. Further studies found that AFB1 destroyed the antioxidant capacity and tight junction complexes (TJs), causing apoptosis in zebrafish larvae. In summary, AFB1 may induce developmental toxicity and inhibit muscle development through oxidative damage, apoptosis and disruption of TJs in zebrafish larvae. Our results revealed the direct toxicity effects of AFB1 on the development of embryos and larvae, including inhibition of muscle development and triggering neurotoxicity, induction of oxidative damage, apoptosis and disruption of TJs, and fills the gap in the toxicity mechanism of AFB1 on foetal development.

Endothelin-1 induces connective tissue growth factor expression in human lung fibroblasts by disrupting HDAC2/Sin3A/MeCP2 corepressor complex

BACKGROUND

Reduction of histone deacetylase (HDAC) 2 expression and activity may contribute to amplified inflammation in patients with severe asthma. Connective tissue growth factor (CTGF) is a key mediator of airway fibrosis in severe asthma. However, the role of the HDAC2/Sin3A/methyl-CpG-binding protein (MeCP) 2 corepressor complex in the regulation of CTGF expression in lung fibroblasts remains unclear.

METHODS

The role of the HDAC2/Sin3A/MeCP2 corepressor complex in endothelin (ET)-1-stimulated CTGF production in human lung fibroblasts (WI-38) was investigated. We also evaluated the expression of HDAC2, Sin3A and MeCP2 in the lung of ovalbumin-induced airway fibrosis model.

RESULTS

HDAC2 suppressed ET-1-induced CTGF expression in WI-38 cells. ET-1 treatment reduced HDAC2 activity and increased H3 acetylation in a time-dependent manner. Furthermore, overexpression of HDAC2 inhibited ET-1-induced H3 acetylation. Inhibition of c-Jun N-terminal kinase, extracellular signal-regulated kinase, or p38 attenuated ET-1-induced H3 acetylation by suppressing HDAC2 phosphorylation and reducing HDAC2 activity. Overexpression of both Sin3A and MeCP2 attenuated ET-1-induced CTGF expression and H3 acetylation. ET-1 induced the disruption of the HDAC2/Sin3A/MeCP2 corepressor complex and then prompted the dissociation of HDAC2, Sin3A, and MeCP2 from the CTGF promoter region. Overexpression of HDAC2, Sin3A, or MeCP2 attenuated ET-1-stimulated AP-1-luciferase activity. Moreover, Sin3A- or MeCP2-suppressed ET-1-induced H3 acetylation and AP-1-luciferase activity were reversed by transfection of HDAC2 siRNA. In an ovalbumin-induced airway fibrosis model, the protein levels of HDAC2 and Sin3A were lower than in the control group; however, no significant difference in MeCP2 expression was observed. The ratio of phospho-HDAC2/HDAC2 and H3 acetylation in the lung tissue were higher in this model than in the control group. Overall, without stimulation, the HDAC2/Sin3A/MeCP2 corepressor complex inhibits CTGF expression by regulating H3 deacetylation in the CTGF promoter region in human lung fibroblasts. With ET-1 stimulation, the HDAC2/Sin3A/MeCP2 corepressor complex is disrupted and dissociated from the CTGF promoter region; this is followed by AP-1 activation and the eventual initiation of CTGF production.

CONCLUSIONS

The HDAC2/Sin3A/MeCP2 corepressor complex is an endogenous inhibitor of CTGF in lung fibroblasts. Additionally, HDAC2 and Sin3A may be of greater importance than MeCP2 in the pathogenesis of airway fibrosis.

Bruton's tyrosine kinase inhibition suppresses neutrophilic inflammation and restores histone deacetylase 2 expression in myeloid and structural cells in a mixed granulocytic mouse model of asthma

Asthmatic inflammation is not a single homogenous inflammation but may be categorized into several phenotypes/endotypes. Severe asthma is characterized by mixed granulocytic inflammation in which there is increased presence of neutrophilic numbers and unresponsiveness to corticosteroids. Neutrophilic oxidative stress and histone deacetylase 2 (HDAC2) dysregulation in the pulmonary compartment are thought to lead to corticosteroid insensitivity in severe asthma with mixed granulocytic inflammation. Bruton's tyrosine kinase (BTK) is a no-receptor tyrosine kinase which is expressed in innate immune cells such as neutrophils and dendritic cells (DCs) where it is incriminated in balancing of inflammatory signaling. We hypothesized in this study that BTK inhibition strategy could be utilized to restore corticosteroid responsiveness in mixed granulocytic asthma. Therefore, combined therapy of BTK inhibitor (ibrutinib) and corticosteroid, dexamethasone was administered in cockroach allergen extract (CE)-induced mixed granulocyte airway inflammation model in mice. Our data show that CE-induced neutrophilic inflammation was concomitant with HDAC2 expression and upregulation of p-NFkB expression in airway epithelial cells (AECs), myeloid cells and pulmonary tissue. Further, there were increased expression/release of inflammatory and oxidative mediators such as MUC5AC, TNF-α, GM-CSF, MCP-1, iNOS, nitrotyrosine, MPO, lipid peroxides in AECs/myeloid cells/pulmonary tissue. Dexamethasone alone significantly attenuated eosinophilic inflammation and inflammatory cytokines but was not able to control oxidative inflammation. Ibrutinib alone markedly reduced neutrophilic infiltration and oxidative inflammation, and restored HDAC2 without having any significant effect on eosinophilic inflammation. These data suggest that BTK inhibition strategy may be used in conjunction with dexamethasone to treat both neutrophilic and eosinophilic inflammation, i.e. mixed granulocytic asthma.

Oxidative Stress, Environmental Pollution, and Lifestyle as Determinants of Asthma in Children

Exposure to cigarette smoke, allergens, viruses, and other environmental contaminants, as well as a detrimental lifestyle, are the main factors supporting elevated levels of airway oxidative stress. Elevated oxidative stress results from an imbalance in reactive oxygen species (ROS) production and efficiency in antioxidant defense systems. Uncontrolled increased oxidative stress amplifies inflammatory processes and tissue damage and alters innate and adaptive immunity, thus compromising airway homeostasis. Oxidative stress events reduce responsiveness to corticosteroids. These events can increase risk of asthma into adolescence and prompt evolution of asthma toward its most severe forms. Development of new therapies aimed to restore oxidant/antioxidant balance and active interventions aimed to improve physical activity and quality/quantity of food are all necessary strategies to prevent asthma onset and avoid in asthmatics evolution toward severe forms of the disease.

Tiotropium Bromide Improves Neutrophilic Asthma by Recovering Histone Deacetylase 2 Activity

BACKGROUND

The value of tiotropium bromide (TIO) in neutrophilic asthma was meaningful in previous study. We hypothesized that TIO's mechanism of action is associated with histone deacetylase 2 (HDAC2) activity, which is key for controlling the transcription of inflammatory cytokines and usually downregulated in neutrophilic asthma.

METHODS

The effects of TIO and dexamethasone (DEX) on HDAC2 activity, nuclear factor kappa B (NF-κB), and C-X-C motif chemokine ligand 1 (CXCL1) were evaluated in neutrophilic asthma mouse model (C57BL, 6-week-old). An in-vitro study was conducted using primary human bronchial/tracheal epithelial (HBE) cells from asthma patients. Western blot analyses were performed for phospho-phospholipase Cγ-1 (PLCγ-1) and inositol trisphosphate (IP₃) receptors (IP₃R) with treating lipopolysaccharide (LPS) and TIO.

RESULTS

Ovalbumin was used to induce eosinophilic inflammation in this study. After neutrophilic asthma was induced by LPS (O+L group), HDAC2 activity was diminished with increased NF-κB activity and CXCL1 compared to the control group. TIO significantly improved NF-κB activity, CXCL1, and HDAC2 activity compared with the O+L group in in-vivo study (P < 0.05, each). Western blot analyses showed that LPS treated HBE cells from asthma patients increased PLCγ-1 and diminished IP₃ receptor levels. After TIO treatment, recovery of IP₃R and improved PLCγ-1 levels were observed.

CONCLUSION

These results support the hypothesis that TIO modulates inflammation by recovering HDAC2 activity from the acetylcholine-stimulated inflammation cascade in neutrophilic asthma. The detailed inflammation cascade of recovering HDAC2 activity by TIO might be associated with PLCγ-1-IP₃-IP₃R mediated intracellular calcium ion pathway.

Precision Medicine in Asthma Therapy

Asthma is a complex, heterogeneous disease that necessitates a proper patient evaluation to decide the correct treatment and optimize disease control. The recent introduction of new target therapies for the most severe form of the disease has heralded a new era of treatment options, intending to treat and control specific molecular pathways in asthma pathophysiology. Precision medicine, using omics sciences, investigates biological and molecular mechanisms to find novel biomarkers that can be used to guide treatment selection and predict response. The identification of reliable biomarkers indicative of the pathological mechanisms in asthma is essential to unravel new potential treatment targets. In this chapter, we provide a general description of the currently available -omics techniques, focusing on their implications in asthma therapy.

Challenges in uncontrolled asthma in pediatrics: important considerations for the clinician

INTRODUCTION

Despite symptoms control being the primary focus of asthma management according to guidelines, uncontrolled asthma is still an issue worldwide, leading to huge costs and asthma deaths at all ages. In childhood, poor asthma control can be even more harmful, as it can irreversibly compromise the children's lung function and the whole family's well-being.

AREAS COVERED

Given the problem extent, this review aims to discuss the leading modifiable causes of uncontrolled asthma in Pediatrics, giving some practical insights regarding the critical role of families and the main tools for monitoring control and drug adherence, even at a distance. The most recent GINA documents were used as the primary reference, along with the latest evidence regarding the management of asthma control and the impact of the COVID-19 pandemic on asthma.

EXPERT OPINION

In managing pediatric asthma, a multidisciplinary, multi-determinant, personalized approach is needed, actively involving families, schools, and other specialists. In addition to current strategies for implementing control, electronic health strategies, new validated asthma control tools, and the identification of novel inflammatory biomarkers could lead to increasingly tailored therapies with greater effectiveness in reaching asthma control.

Epigenetic regulation of immune function in asthma

Asthma is a common complex respiratory disease characterized by chronic airway inflammation and partially reversible airflow obstruction resulting from genetic and environmental determinants. Because epigenetic marks influence gene expression and can be modified by both environmental exposures and genetic variation, they are increasingly recognized as relevant to the pathogenesis of asthma and may be a key link between environmental exposures and asthma susceptibility. Unlike changes to DNA sequence, epigenetic signatures are dynamic and reversible, creating an opportunity for not only therapeutic targets but may serve as biomarkers to follow disease course and identify molecular subtypes in heterogeneous diseases such as asthma. In this review, we will examine the relationship between asthma and 3 key epigenetic processes that modify gene expression: DNA methylation, modification of histone tails, and noncoding RNAs. In addition to presenting a comprehensive assessment of the existing epigenetic studies focusing on immune regulation in asthma, we will discuss future directions for epigenetic investigation in allergic airway disease.

[Genetic aspects involved in asthma]

Asthma is an etiologically heterogeneous disease resulting from a complex interaction between genetic. The genetic aspects involved in asthma, which were analyzed from the perspective of the traditional model of multifactorial inheritance, were susceptibility, host factors, and environmental exposures. In the present paper, studies on their family aggregation, concordance in twins, and heritability were analized; as well as the current knowledge about candidate genes, genome wide association studies, and epigenomics contributions and other omic studies that have increased our knowledge about their pathophysiology and environmental interactions.

An Overview of the Obese-Asthma Phenotype in Children

Asthma is the most common chronic disease in childhood. Overweight and obesity are included among the comorbidities considered in patients with difficult-to-treat asthma, suggesting a specific phenotype of the disease. Therefore, the constant increase in obesity prevalence in children and adolescents raises concerns about the parallel increase of obesity-associated asthma. The possible correlation between obesity and asthma has been investigated over the last decade by different authors, who suggest a complex multifactorial relationship. Although the particular non-eosinophilic endotype of obesity-related asthma supports the concept that high body weight precedes asthma development, there is ongoing debate about the direct causality of these two entities. A number of mechanisms may be involved in asthma in combination with obesity disease in children, including reduced physical activity, abnormal ventilation, chronic systemic inflammation, hormonal influences, genetics and additional comorbidities, such as gastroesophageal reflux and dysfunctional breathing. The identification of the obesity-related asthma phenotype is crucial to initiate specific therapeutic management. Besides the cornerstones of asthma treatment, lifestyle should be optimized, with interventions aiming to promote physical exercise, healthy diet, and comorbidities. Future studies should clarify the exact association between asthma and obesity and the mechanisms underlying the pathogenesis of these two related conditions with the aim to define personalized therapeutic strategies for asthma management in this population.

Epigenetic regulation of pediatric and neonatal immune responses

Epigenetic regulation of transcription is a collective term that refers to mechanisms known to regulate gene transcription without changing the underlying DNA sequence. These mechanisms include DNA methylation and histone tail modifications which influence chromatin accessibility, and microRNAs that act through post-transcriptional gene silencing. Epigenetics is known to regulate a variety of biological processes, and the role of epigtenetics in immunity and immune-mediated diseases is becoming increasingly recognized. While DNA methylation is the most widely studied, each of these systems play an important role in the development and maintenance of appropriate immune responses. There is clear evidence that epigenetic mechanisms contribute to developmental stage-specific immune responses in a cell-specific manner. There is also mounting evidence that prenatal exposures alter epigenetic profiles and subsequent immune function in exposed offspring. Early life exposures that are associated with poor long-term health outcomes also appear to impact immune specific epigenetic patterning. Finally, each of these epigenetic mechanisms contribute to the pathogenesis of a wide variety of diseases that manifest during childhood. This review will discuss each of these areas in detail. IMPACT: Epigenetics, including DNA methylation, histone tail modifications, and microRNA expression, dictate immune cell phenotypes. Epigenetics influence immune development and subsequent immune health. Prenatal, perinatal, and postnatal exposures alter immune cell epigenetic profiles and subsequent immune function. Numerous pediatric-onset diseases have an epigenetic component. Several successful strategies for childhood diseases target epigenetic mechanisms.

Molecular mechanisms of oxidative stress in asthma

The lungs are exposed to reactive oxygen species oxygen (ROS) produced as a result of inhalation of oxygen, as well as smoke and other air pollutants. Cell metabolism and the NADPH oxidases (Nox) generate low levels of intracellular ROS that act as signal transduction mediators by inducing oxidative modifications of histones, enzymes and transcription factors. Redox signalling is also regulated by localised production and sensing of ROS in mitochondria, the endoplasmic reticulum (ER) and inside the nucleus. Intracellular ROS are maintained at low levels through the action of a battery of enzymatic and non-enzymatic antioxidants. Asthma is a heterogeneous airway inflammatory disease with different immune endotypes; these include atopic or non-atopic Th2 type immune response associated with eosinophilia, or a non-Th2 response associated with neutrophilia. Airway remodelling and hyperresponsiveness accompany the inflammatory response in asthma. Over-production of ROS resulting from infiltrating immune cells, particularly eosinophils and neutrophils, and a concomitant impairment of antioxidant responses lead to development of oxidative stress in asthma. Oxidative stress is augmented in severe asthma and during exacerbations, as well as by air pollution and obesity, and causes oxidative damage of tissues promoting airway inflammation and hyperresponsiveness. Furthermore, deregulated Nox activity, mitochondrial dysfunction, ER stress and/or oxidative DNA damage, resulting from exposure to irritants, inflammatory mediators or obesity, may lead to redox-dependent changes in cell signalling. ROS play a central role in airway epithelium-mediated sensing, development of innate and adaptive immune responses, and airway remodelling and hyperresponsiveness. Nonetheless, antioxidant compounds have proven clinically ineffective as therapeutic agents for asthma, partly due to issues with stability and in vivo metabolism of these compounds. The compartmentalised nature of ROS production and sensing, and the role of ROS in homeostatic responses and in the action of corticosteroids and β2-adrenergic receptor agonists, adds another layer of complexity to antioxidant therapy development. Nox inhibitors and mitochondrial-targeted antioxidants are in clinical development for a number of diseases but they have not yet been investigated in asthma. A better understanding of the complex role of ROS in the pathogenesis of asthma will highlight new opportunities for more targeted and effective redox therapies.

Genes, environment, and developmental timing: New insights from translational approaches to understand early origins of respiratory diseases

Over the past decade, "omics" approaches have advanced our understanding of the molecular programming of the airways in humans. Several studies have identified potential molecular mechanisms that contribute to early life epigenetic reprogramming, including DNA methylation, histone modifications, microRNAs, and the homeostasis of the respiratory mucosa (epithelial function and microbiota). Current evidence supports the notion that early infancy is characterized by heightened susceptibility to airway genetic reprogramming in response to the first exposures in life, some of which can have life-long consequences. Here, we summarize and analyze the latest insights from studies that support a novel epigenetic paradigm centered on human maturational and developmental programs including three cardinal elements: genes, environment, and developmental timing. The combination of these factors is likely responsible for the functional trajectory of the respiratory system at the molecular, functional, and clinical levels.

Oxidative Stress Promotes Corticosteroid Insensitivity in Asthma and COPD

Corticosteroid insensitivity is a key characteristic of patients with severe asthma and COPD. These individuals experience greater pulmonary oxidative stress and inflammation, which contribute to diminished lung function and frequent exacerbations despite the often and prolonged use of systemic, high dose corticosteroids. Reactive oxygen and nitrogen species (RONS) promote corticosteroid insensitivity by disrupting glucocorticoid receptor (GR) signaling, leading to the sustained activation of pro-inflammatory pathways in immune and airway structural cells. Studies in asthma and COPD models suggest that corticosteroids need a balanced redox environment to be effective and to reduce airway inflammation. In this review, we discuss how oxidative stress contributes to corticosteroid insensitivity and the importance of optimizing endogenous antioxidant responses to enhance corticosteroid sensitivity. Future studies should aim to identify how antioxidant-based therapies can complement corticosteroids to reduce the need for prolonged high dose regimens in patients with severe asthma and COPD.

CpG oligodeoxynucleotides attenuate RORγt-mediated Th17 response by restoring histone deacetylase-2 in cigarette smoke-exposure asthma

BACKGROUND

Cigarette smoke (CS) exposure increases corticosteroid insensitive asthma related to increased Th17 phenotype, and new treatment strategies are needed for CS-associated asthma. Histone deacetylase 2 (HDAC2), found in the airway epithelium, is critical for ameliorating glucocorticoids insensitivity. We recently demonstrated the anti-inflammatory effects of CpG oligodeoxynucleotides (CpG-ODNs) on CS-exposure asthma. However, the effects of CpG-ODNs on HDAC2 expression and enzymatic activity remain unclear. This study aimed to assess whether CpG-ODNs protect against excessive Th17 immune responses in CS-induced asthma through HDAC2-dependent mechanisms and compared their effects with those of corticosteroids.

METHODS

The effects of CpG-ODNs alone and in combination with budesonide (BUD) on airway inflammation and Th2/Th17-related airway immune responses were determined using an in vivo model of CS-induced asthma and in cultured bronchial epithelial (HBE) cells administered ovalbumin (OVA) and/or cigarette smoke extract (CSE). HDAC2 and retinoid-related orphan nuclear receptor γt (RORγt) expression were also assessed in mouse lung specimens and HBE cells.

RESULTS

CpG-ODNs and BUD synergistically attenuated CS exposure asthmatic responses in vivo by modulating the influx of eosinophils and neutrophils, airway remodeling, Th2/Th17 associated cytokine and chemokine production, and airway hyperresponsiveness and blocking RORγt-mediated Th17 inflammation through induced HDAC2 expression/activity. In vitro, CpG-ODNs synergized with BUD to inhibit Th17 cytokine production in OVA- and CSE-challenged HBE cells while suppressing RORγt and increasing epithelial HDAC2 expression/activity.

CONCLUSIONS

CpG-ODNs reversed CS-induced HDAC2 downregulation and enhanced the sensitivity of CS-exposed asthmatic mice and CSE-induced HBE cells to glucocorticoid treatment. This effect may be associated with HDAC2 restoration via RORγt/IL-17 pathway regulation, suggesting that CpG-ODNs are potential corticosteroid-sparing agents for use in CS-induced asthma with Th17-biased immune conditions.

Difficult and Severe Asthma in Children

Asthma is the most frequent chronic inflammatory disease of the lower airways affecting children, and it can still be considered a challenge for pediatricians. Although most asthmatic patients are symptom-free with standard treatments, a small percentage of them suffer from uncontrolled persistent asthma. In these children, a multidisciplinary systematic assessment, including comorbidities, treatment-related issues, environmental exposures, and psychosocial factors is needed. The identification of modifiable factors is important to differentiate children with difficult asthma from those with true severe therapy-resistant asthma. Early intervention on modifiable factors for children with difficult asthma allows for better control of asthma without the need for invasive investigation and further escalation of treatment. Otherwise, addressing a correct diagnosis of true severe therapy-resistant asthma avoids diagnostic and therapeutic delays, allowing patients to benefit from using new and advanced biological therapies.

Network Pharmacology Strategy to Investigate the Pharmacological Mechanism of HuangQiXiXin Decoction on Cough Variant Asthma and Evidence-Based Medicine Approach Validation

Objective

To investigate the pharmacological mechanism of HuangQiXiXin decoction (HQXXD) on cough variant asthma (CVA) and validate the clinical curative effect.

Methods

The active compounds and target genes of HQXXD were searched using TCMSP. CVA-related target genes were obtained using the GeneCards database. The active target genes of HQXXD were compared with the CVA-related target genes to identify candidate target genes of HQXXD acting on CVA. A medicine-compound-target network was constructed using Cytoscape 3.6.0 software, and a protein-protein interaction (PPI) network was constructed using the STRING database. Gene ontology (GO) function enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed using RGUI3.6.1 and Cytoscape 3.6.0. We searched the main database for randomized controlled trials of HQXXD for CVA. We assessed the quality of the included studies using the Cochrane Reviewers' Handbook. A meta-analysis of the clinical curative effect of HQXXD for CVA was conducted using the Cochrane Collaboration's RevMan 5.3 software.

Results

We screened out 48 active compounds and 217 active target genes of HQXXD from TCMSP. The 217 active target genes of HQXXD were compared with the 1481 CVA-related target genes, and 132 candidate target genes for HQXXD acting on CVA were identified. The medicine-compound-target network and PPI network were constructed, and the key compounds and key targets were selected. GO function enrichment and KEGG pathway enrichment analysis were performed. Meta-analysis showed that the total effective rate of the clinical curative effect was significantly higher in the experimental group than the control group.

Conclusion

The pharmacological mechanism of HQXXD acting on CVA has been further determined, and the clinical curative effect of HQXXD on CVA is remarkable.

An approach to the management of children with problematic severe asthma

Children with poor asthma control despite high levels of prescribed treatment are described as having problematic severe asthma. Most of these children have steroid sensitive disease which improves with adherence to daily inhaled corticosteroids and after having removed modifiable factors like poor inhalation technique, persistent adverse environmental exposures and psychosocial factors. These children are described as having “difficult-to-treat asthma” while children with persistent symptoms despite above-mentioned factors having been addressed are described as having “severe therapy-resistant asthma”. In this review, we will describe the 6-step approach to the diagnosis and management of a child with problematic severe asthma adopted by The Royal Brompton Hospital (London, UK). The role of a multidisciplinary team is crucial for identification and treatment of modifiable factors and comorbidities in order to avoid invasive examinations and useless pharmacological treatments. The current knowledge on add-on therapies will be discussed.

Pharmacogenomic Response of Inhaled Corticosteroids for the Treatment of Asthma: Considerations for Therapy

There is a large interindividual variability in response to ICSs in asthma. About 70% of the variance in ICS response is likely due at least partially to genetically determined characteristics of target genes. In this article, we examine the effects on the ICS response of gene variations in the corticosteroid pathway, and in the pharmacokinetics of corticosteroids, and also those outside the corticosteroid pathway, which have the potential to influence corticosteroid activity. Although the available evidence indicates that responses to ICSs in asthma are influenced by different genetic variants, there are still deep uncertainties as to whether a real association between these genetic variants and corticosteroid response could also possibly exist because there are difficulties in reproducing pharmacogenetic findings. This explains at least partly the insufficient use of pharmacogenomic data when treating asthmatic patients, which creates a real limitation to the proper use of ICSs in an era of precision medicine that links the right patient to the right treatment. Knowing and dealing with the genetic factors that influence the therapeutic ICS response is a fundamental condition for prescribing the right dose of ICS to the right patient at the right time.

Influence of Second-Hand Smoke and Prenatal Tobacco Smoke Exposure on Biomarkers, Genetics and Physiological Processes in Children-An Overview in Research Insights of the Last Few Years

Children are commonly exposed to second-hand smoke (SHS) in the domestic environment or inside vehicles of smokers. Unfortunately, prenatal tobacco smoke (PTS) exposure is still common, too. SHS is hazardous to the health of smokers and non-smokers, but especially to that of children. SHS and PTS increase the risk for children to develop cancers and can trigger or worsen asthma and allergies, modulate the immune status, and is harmful to lung, heart and blood vessels. Smoking during pregnancy can cause pregnancy complications and poor birth outcomes as well as changes in the development of the foetus. Lately, some of the molecular and genetic mechanisms that cause adverse health effects in children have been identified. In this review, some of the current insights are discussed. In this regard, it has been found in children that SHS and PTS exposure is associated with changes in levels of enzymes, hormones, and expression of genes, micro RNAs, and proteins. PTS and SHS exposure are major elicitors of mechanisms of oxidative stress. Genetic predisposition can compound the health effects of PTS and SHS exposure. Epigenetic effects might influence in utero gene expression and disease susceptibility. Hence, the limitation of domestic and public exposure to SHS as well as PTS exposure has to be in the focus of policymakers and the public in order to save the health of children at an early age. Global substantial smoke-free policies, health communication campaigns, and behavioural interventions are useful and should be mandatory.

Sputum microbiome profiles identify severe asthma phenotypes of relative stability at 12 to 18 months

BACKGROUND

Asthma is a heterogeneous disease characterized by distinct phenotypes with associated microbial dysbiosis.

OBJECTIVES

Our aim was to identify severe asthma phenotypes based on sputum microbiome profiles and assess their stability after 12 to 18 months. A further aim was to evaluate clusters' robustness after inclusion of an independent cohort of patients with mild-to-moderate asthma.

METHODS

In this longitudinal multicenter cohort study, sputum samples were collected for microbiome profiling from a subset of the Unbiased Biomarkers in Prediction of Respiratory Disease Outcomes adult patient cohort at baseline and after 12 to 18 months of follow-up. Unsupervised hierarchical clustering was performed by using the Bray-Curtis β-diversity measure of microbial profiles. For internal validation, partitioning around medoids, consensus cluster distribution, bootstrapping, and topological data analysis were applied. Follow-up samples were studied to evaluate within-patient clustering stability in patients with severe asthma. Cluster robustness was evaluated by using an independent cohort of patients with mild-to-moderate asthma.

RESULTS

Data were available for 100 subjects with severe asthma (median age 55 years; 42% males). Two microbiome-driven clusters were identified; they were characterized by differences in asthma onset, smoking status, residential locations, percentage of blood and/or sputum neutrophils and macrophages, lung spirometry results, and concurrent asthma medications (all P values < .05). The cluster 2 patients displayed a commensal-deficient bacterial profile that was associated with worse asthma outcomes than those of the cluster 1 patients. Longitudinal clusters revealed high relative stability after 12 to 18 months in those with severe asthma. Further inclusion of an independent cohort of 24 patients with mild-to-moderate asthma was consistent with the clustering assignments.

CONCLUSION

Unbiased microbiome-driven clustering revealed 2 distinct robust phenotypes of severe asthma that exhibited relative overtime stability. This suggests that the sputum microbiome may serve as a biomarker for better characterizing asthma phenotypes.

Passive Smoking Exposure and Perceived Health Status in Children Seeking Pediatric Care Services at a Vietnamese Tertiary Hospital

Understanding the predictors of health conditions and exposure to secondhand smoke among children is necessary to determine the severity of the issues and identify effective solutions. Despite the significant prevalence in smoking and child exposure to secondhand smoke, there have been only a few studies focusing on this area in Vietnam, and thus the current study aims to fill in this gap. The questionnaires of 435 children aged between 0 and 6 and their caregivers, who agreed to participate in the research, were collected at the Pediatric Department of Bach Mai hospital, Hanoi, in 2016. Multivariable logistic regression was employed to identify factors associated with perceived health status and exposure to secondhand smoke among children in the last 24 h and the last 7 days from the date of the survey. Our study found that 43% of the respondents had smokers in the family, and 46.4% of children were exposed to passive smoking in the last 7 days. Urban children were most frequently exposed to passive smoking at home and in public, whereas in the rural area, the home and relatives’ houses were the most common places for exposure. Compared to children whose caregivers were farmers, children of non-government workers were more likely to be exposed to passive smoking in the last 7 days. Moreover, children in a family having smoking rules and no smokers were less likely to be exposed to passive smoking in the last 24 h and 7 days than those living in a family allowing smoking and having smokers. In conclusion, our study shows that the government needs to implement better public smoking monitoring and encourage caregivers to implement smoke-free households or smoking rules in their houses.

Recent findings in the genetics and epigenetics of asthma and allergy

In asthma and allergy genetics, a trend towards a few main topics developed over the last 2 years. First, a number of studies have been published recently which focus on overlapping and/or very specific phenotypes: within the allergy spectrum but also reaching beyond, looking for common genetic traits shared between different diseases or disease entities. Secondly, an urgently needed focus has been put on asthma and allergy genetics in populations genetically different from European ancestry. This acknowledges that the majority of new asthma patients today are not white and asthma is a truly worldwide disease. In epigenetics, recent years have seen several large-scale epigenome-wide association studies (EWAS) being published and a further focus was on the interaction between the environment and epigenetic signatures. And finally, the major trends in current asthma and allergy genetics and epigenetics comes from the field of pharmacogenetics, where it is necessary to understand the susceptibility for and mechanisms of current asthma and allergy therapies while at the same time, we need to have scientific answers to the recent availability of novel drugs that hold the promise for a more individualized therapy.

Asthma and Corticosteroid Responses in Childhood and Adult Asthma

Corticosteroids are the most effective treatment for asthma; inhaled corticosteroids (ICSs) are the first-line treatment for children and adults with persistent symptoms. ICSs are associated with significant improvements in lung function. The anti-inflammatory effects of corticosteroids are mediated by both genomic and nongenomic factors. Variation in the response to corticosteroids has been observed. Patient characteristics, biomarkers, and genetic features may be used to predict response to ICSs. The existence of multiple mechanisms underlying glucocorticoid insensitivity raises the possibility that this might indeed reflect different diseases with a common phenotype.

A translational perspective on epigenetics in allergic diseases

The analysis of epigenetic modifications in allergic diseases has recently attracted substantial interest because epigenetic modifications can mediate the effects of the environment on the development of or protection from allergic diseases. Furthermore, recent research has provided evidence for an altered epigenomic landscape in disease-relevant cell populations. Although still in the early phase, epigenetic modifications, particularly DNA methylation and microRNAs, might have potential for assisting in the stratification of patients for treatment and complement or replace in the future biochemical or clinical tests. The first epigenetic biomarkers correlating with the successful outcome of immunotherapy have been reported, and with personalized treatment options being rolled out, epigenetic modifications might well play a role in monitoring or even predicting the response to tailored therapy. However, further studies in larger cohorts with well-defined phenotypes in specific cell populations need to be performed before their implementation. Furthermore, the epigenome provides an interesting target for therapeutic intervention, with microRNA mimics, inhibitors, and antisense oligonucleotides being evaluated in clinical trials in patients with other diseases. Selection or engineering of populations of extracellular vesicles and epigenetic editing represent novel tools for modulation of the cellular phenotype and responses, although further technological improvements are required. Moreover, interactions between the host epigenome and the microbiome are increasingly recognized, and interventions of the microbiome could contribute to modulation of the epigenome with a potential effect on the overall goal of prevention of allergic diseases.

Expression of GR-α and HDAC2 in steroid-Sensitive and steroid-Insensitive interstitial lung disease

BACKGROUND

Corticosteroid is one of the main treatments for interstitial lung disease (ILD). Cryptogenic-organizing pneumonia (COP) is sensitive to corticosteroid therapy, whereas idiopathic pulmonary fibrosis (IPF) is not. Glucocorticoid receptor-α (GR-α) and histone deacetylase 2 (HDAC2) play critical roles in the sensitivity to corticosteroid therapy; however, it is unclear whether HDAC2 and/or GR-α are expressed in the lung tissues of patients with COP and/or IPF. Possible aberrant expressions of HDAC2 and GR-α in IPF and COP were investigated in the current study.

METHODS

Lung tissue samples were obtained from patients with COP (n = 9), IPF (n = 8), pulmonary abscesses (n = 7), or pulmonary inflammatory pseudotumors (n = 6) before corticosteroid treatment, as well as from control subjects (n = 10). The expression of GR-α, HDAC2, PI3K-δ, and NF-κBp65 in the samples was assessed by immunohistochemistry.

RESULTS

GR-α expression was the same in lung tissues from COP patients and control subjects, but was significantly lower in lung tissue from IPF. In addition, HDAC2 was significantly higher in lung tissues of COP patients compared to both IPF and control subjects. Furthermore, the transcription factor NF-κBp65 was significantly lower in lung tissues from both COP and control compared to IPF subjects, whereas there was no difference in NF-κBp65 when comparing tissues from COP patients to controls. HDAC2 and GR-α were negatively correlated with NF-κBp65 in COP lung tissue.

CONCLUSION

HDAC2 and GR-α expression in lung tissues are potential biomarkers for predicting corticosteroid sensitivity when initially treating COP and IPF, as well as other forms of ILD.

PARP inhibition by olaparib alleviates chronic asthma-associated remodeling features via modulating inflammasome signaling in mice

Despite the reported role of poly(ADP-ribose) polymerase (PARP) in asthma inflammation, its contribution during remodeling is not clearly known. The main aim of the current investigation was to examine the potential of olaparib, a pharmacological inhibitor of PARP against airway remodeling using an ovalbumin (OVA)-based murine model of chronic asthma. The results demonstrated that post-challenge olaparib treatment (5 mg/kg i.p., 30 min after OVA exposure) for six weeks (3 days/week) attenuates inflammation, mucus production, and collagen deposition in lungs. Additionally, olaparib blunted the protein expression of STAT-6 and GATA-3 considerably along with a modest reduction in p65-NF-κB phosphorylation. Furthermore, olaparib normalized the OVA-induced redox imbalance as reflected by data on reactive oxygen species, malondialdehyde, protein carbonyls, and reduced glutathione/oxidized glutathione ratio. Interestingly, the protection offered by olaparib was further linked with the altered level of NLRP3 inflammasome-mediated IL-1β release and consequent expression of its downstream targets matrix metalloproteinase-9 and transforming growth factor beta. Suppressed collagen deposition in the lungs correlates well with the reduced expression of vimentin upon olaparib treatment. Finally, olaparib restored the expression of histone deacetylase 2, a steroid-responsive element in asthma. Overall, results suggest that olaparib prevents OVA-induced airway inflammation as well as remodeling via modulating inflammasome signaling in mice. © 2019 IUBMB Life, 1-11, 2019.

Critical role of CCL4 in eosinophil recruitment into the airway

BACKGROUND

Excessive eosinophil airway infiltration is a clinically critical condition in some cases. Eosinophilic pneumonia (EP) is a pulmonary condition involving eosinophil infiltration of the lungs. Although several chemokines, including eotaxin-1 (CCL11), RANTES (CCL5) and macrophage inflammatory protein 1β (MIP-1β or CCL4), have been detected in bronchoalveolar lavage fluid (BALF) from patients with EP, the pathophysiological mechanisms underlying EP, including potential relationships between eosinophils and CCL4, have not been fully elucidated.

OBJECTIVE

To examine the involvement of CCL4 in eosinophilic airway inflammation.

METHODS

We analysed supernatants of activated eosinophils and BALF from 16 patients with eosinophilic pneumonia (EP). Further, we examined the effects of CCL4 on eosinophil functions in vitro and those of anti-CCL4 neutralizing antibody in an in vivo model.

RESULTS

We found that purified human eosinophils stimulated with IL-5 predominantly secreted CCL4 and that patients with EP had elevated CCL11 and CCL4 levels in BALF compared with samples from individuals without EP. Because CCL4 levels were more strongly correlated with eosinophil count and expression of eosinophil granule proteins than CCL11, in vitro experiments using purified eosinophils concentrated on the former chemokine. Interestingly, CCL4 acted as a chemoattractant for eosinophils. In a mouse model, administration of a CCL4-neutralizing antibody attenuated eosinophilic airway infiltration and airway hyperresponsiveness.

CONCLUSIONS AND CLINICAL RELEVANCE

Overall, these findings highlight an important role of CCL4 in the mechanisms underlying eosinophil recruitment into the airway and may provide a novel insight into this potential therapeutic target.

Severe Asthma-Perspectives From Adult and Pediatric Pulmonology

Both adults and children with severe asthma represent a small proportion of the asthma population; however, they consume disproportionate resources. For both groups it is important to confirm the diagnosis of severe asthma and ensure that modifiable factors such as adherence have, as far as possible, been addressed. Most children can be controlled on inhaled corticosteroids and long term oral corticosteroid use is rare, in contrast to adults where steroid related morbidity accounts for a large proportion of the costs of severe asthma. Atopic sensitization is very common in children with severe asthma as are other atopic conditions such as allergic rhinitis and hay fever which can impact on asthma control. In adults, the role of allergic driven disease, even in those with co-existent evidence of sensitization, is unclear. There is currently an exciting pipeline of novel biologicals, particularly directed at Type 2 inflammation, which afford the possibility of improved asthma control and reduced treatment side effects for people with asthma. However, not all drugs will work for all patients and accurate phenotyping is essential. In adults the terms T2 high and T2 low asthma have been coined to describe groups of patients based on the presence/absence of eosinophilic inflammation and T-helper 2 (TH₂) cytokines. Bronchoscopic studies in children with severe asthma have demonstrated that these children are predominantly eosinophilic but the cytokine patterns do not fit the T2 high paradigm suggesting other steroid resistant pathways are driving the eosinophilic inflammation. It remains to be seen whether treatments developed for adult severe asthma will be effective in children and which biomarkers will predict response.

HDAC2 attenuates airway inflammation by suppressing IL-17A production in HDM-challenged mice

Histone deacetylase (HDAC)2 is expressed in airway epithelium and plays a pivotal role in inflammatory cells. However, the role of HDAC2 in allergic airway inflammation remains poorly understood. In the present study, we determined the role of HDAC2 in airway inflammation using in vivo models of house dust mite (HDM)-induced allergic inflammation and in vitro cultures of human bronchial epithelial (HBE) cells exposed to HDM, IL-17A, or both. We observed that HDM-challenged Hdac2^+/- mice exhibited substantially enhanced infiltration of inflammatory cells. Higher levels of T helper 2 cytokines and IL-17A expression were found in lung tissues of HDM-challenged Hdac2^+/- mice. Interestingly, IL-17A deletion or anti-IL-17A treatment reversed the enhanced airway inflammation induced by HDAC2 impairment. In vitro, HDM and IL-17A synergistically decreased HDAC2 expression in HBE cells. HDAC2 gene silencing further enhanced HDM- and/or IL-17A-induced inflammatory cytokines in HBE cells. HDAC2 overexpresion or blocking IL-17A gene expression restored the enhanced inflammatory cytokines. Collectively, these results support a protective role of HDAC2 in HDM-induced airway inflammation by suppressing IL-17A production and might suggest that activation of HDAC2 and/or inhibition of IL-17A production could prevent the development of allergic airway inflammation.

Environmental risk factors for asthma in 13-14 year old African children

Background Asthma prevalence in African children is high. Factors driving the prevalence or disease severity are poorly understood. This study aims to investigate environmental factors associated with asthma and severity in African children. Methods Population based cross-sectional study of children aged 13-14 years from 10 African centers who participated in ISAAC III. Self-reported environmental exposures included engaging in physical exercise, television watching, various biomass and ETS exposure, consumption of paracetamol, large family sizes and having pets in the home. Univariable and multivariable analyses were done adjusting for center variations. Prevalences, odds ratio and 95% confidence intervals (CI) were calculated. Results There were 258 267 children recruited among the 13-14-year-old participants. Of these, 28,391 respondents from 232 schools completed both the written questionnaire (WQ) and environmental questionnaire (EQ). The prevalence of asthma and severe asthma were 12.8% (CI 12.4-13.2), and 8.7% (CI 8.4-8.0) respectively. Factors strongly associated with asthma were maternal smoking (OR = 1.41; 95%CI: 1.23-1.64), open fire heating (OR = 1.28; 95%CI: 1.08-1.51) electric heating (OR = 1.13; 95%CI: 1.01-1.28), physical exercise (OR = 1.29; 95%CI: 1.11-1.50), monthly paracetamol use (OR 1.23; 95%CI 1.13-1.33), having an elder sibling (OR = 0.87; 95%CI 0.77-0.98). Factors associated with severe asthma were maternal smoking (OR = 1.61; 95%CI: 1.38-1.89), cat pet (OR = 1.14; 95%CI: 1.04-1.25), frequent physical exercise (OR = 1.42; 95%CI: 1.23-1.64) and monthly paracetamol use (OR = 1.20; 95%CI 1.07, 1.34). Conclusion Several environmental exposures were associated with asthma and severe disease.

Management of asthma in children

This manuscript takes a challenging look at the management of asthma in childhood, in particular in the light of the recent Lancet commission. One of the central pillars of the Commission is the need to deliver personalized medicine for airway disease by deconstructing the airway into components of fixed and variable airflow obstruction, inflammation and infection. Before any treatment for asthma, a diagnostic workup is essential to exclude other conditions. A diagnosis of asthma needs to be based on objective evidence of bronchodilator sensitive variable airflow obstruction, eosinophilic airway inflammation and atopy. Most children with atopic asthma respond to low dose inhaled corticosteroids, sometimes requiring a long acting β-agonist. If the response is unsatisfactory, then, rather than escalate treatment, an approach for which there is little evidence, a full review of the child should be undertaken, including extrapulmonary comorbidities, adherence and adverse environmental influences. If these cannot or will not be addressed by the family, then further treatment including biologicals may be indicated. Asthma attacks are an important warning sign and should always be taken seriously, including a focused reassessment of all aspects of the management of the child. Finally, preschool children with wheeze can also be evaluated for eosinophilic airway inflammation using peripheral blood eosinophil count as a surrogate. It is essential that we start to deliver personalized medicine to children with airway disease.

Difficult vs. Severe Asthma: Definition and Limits of Asthma Control in the Pediatric Population

Evaluating the degree of disease control is pivotal when assessing a patient with asthma. Asthma control is defined as the degree to which manifestations of the disease are reduced or removed by therapy. Two domains of asthma control are identified in the guidelines: symptom control and future risk of poor asthma outcomes, including asthma attacks, accelerated decline in lung function, or treatment-related side effects. Over the past decade, the definition and the tools of asthma control have been substantially implemented so that the majority of children with asthma have their disease well controlled with standard therapies. However, a small subset of asthmatic children still requires maximal therapy to achieve or maintain symptom control and experience considerable morbidity. Childhood uncontrolled asthma is a heterogeneous group and represents a clinical and therapeutic challenge requiring a multidisciplinary systematic assessment. The identification of the factors that may contribute to the gain or loss of control in asthma is essential in differentiating children with difficult-to-treat asthma from those with severe asthma that is resistant to traditional therapies. The aim of this review is to focus on current concept of asthma control, describing monitoring tools currently used to assess asthma control in clinical practice and research, and evaluating comorbidities and modifiable and non-modifiable factors associated with uncontrolled asthma in children, with particular reference to severe asthma.

Active and passive smoking impacts on asthma with quantitative and temporal relations: A Korean Community Health Survey

This study aimed to evaluate the relations of smoking with asthma and asthma-related symptoms, considering quantitative and temporal influences. The 820,710 Korean adults in the Korean Community Health Survey in 2009, 2010, 2011, and 2013 were included and classified as non-smoker, past smoker or current smoker. Total smoking years, total pack-years, and age at smoking onset were assessed. Information on wheezing, exercise wheezing, and aggravation of asthma in the past 12 months and asthma diagnosis history and current treatment was collected. Multiple logistic regression analysis with complex sampling was used. Current and former smokers showed significant positive relations with wheezing, exercise wheezing, asthma ever, current asthma, and asthma aggravation. Current smokers demonstrated higher adjusted odd ratios (AORs) for wheezing, exercise wheezing, and asthma aggravation than former smokers. Former smokers showed higher AORs than current smokers for current asthma treatment. Longer passive smoking was related to wheezing and exercise wheezing. Greater age at smoking onset and duration since cessation were negatively related to wheezing, exercise wheezing, and current asthma; total pack-years demonstrated proportional associations with these symptoms. Former, current, and passive smoking was positively correlated with wheezing and exercise wheezing. Total pack-years and early initiation were increasingly related to asthma.

Histone modifications and their role in epigenetics of atopy and allergic diseases

This review covers basic aspects of histone modification and the role of posttranslational histone modifications in the development of allergic diseases, including the immune mechanisms underlying this development. Together with DNA methylation, histone modifications (including histone acetylation, methylation, phosphorylation, ubiquitination, etc.) represent the classical epigenetic mechanisms. However, much less attention has been given to histone modifications than to DNA methylation in the context of allergy. A systematic review of the literature was undertaken to provide an unbiased and comprehensive update on the involvement of histone modifications in allergy and the mechanisms underlying this development. In addition to covering the growing interest in the contribution of histone modifications in regulating the development of allergic diseases, this review summarizes some of the evidence supporting this contribution. There are at least two levels at which the role of histone modifications is manifested. One is the regulation of cells that contribute to the allergic inflammation (T cells and macrophages) and those that participate in airway remodeling [(myo-) fibroblasts]. The other is the direct association between histone modifications and allergic phenotypes. Inhibitors of histone-modifying enzymes may potentially be used as anti-allergic drugs. Furthermore, epigenetic patterns may provide novel tools in the diagnosis of allergic disorders.

The role of HDAC2 in cigarette smoke-induced airway inflammation in a murine model of asthma and the effect of intervention with roxithromycin

BACKGROUND

Cigarette smoke is well known to worsen asthma symptoms in asthmatic patients and to make them refractory to treatment, but the underling molecular mechanism is unclear. We hypothesized that cigarette smoke can reduce the expression of HDAC2 in asthma and the process was achieved by activating the PI3K-δ/Akt signaling pathway. We further hypothesized that roxithromycin (RXM) can alleviate the impacts by cigarette smoke.

METHODS

A murine model of asthma induced by ovalbumin (OVA) and cigarette smoke has been established. The infiltration of inflammatory cells and inflammatory factors was examined in this model. Finally, we evaluated the expression of HDAC2, Akt phosphorylation levels, and the effects of RXM treatment on the model described earlier.

RESULTS

Cigarette smoke exposure reduced HDAC2 protein expression by enhancing the phosphorylation of Akt in PI3K-δ/Akt signaling pathway. Furthermore, RMX reduced the airway inflammation and improved the level of expression of HDAC2 in the cigarette smoke-exposed asthma mice.

CONCLUSIONS

This study provides a novel insight into the mechanism of cigarette smoke exposure in asthma and the effects of RXM treatment on this condition. These results may be helpful for treating refractory asthma and emphasizing the need for a smoke-free environment for asthmatic patients.

Severe Asthma in Children

Severe asthma in children is associated with significant morbidity and is a highly heterogeneous disorder with multiple clinical phenotypes. Cluster analyses have been performed in several groups to explain some of the heterogeneity of pediatric severe asthma, which is reviewed in this article. The evaluation of a child with severe asthma includes a detailed diagnostic assessment and excluding other possible diagnoses and addressing poor control due to comorbidities, lack of adherence to asthma controller medications, poor technique, and other psychological and environmental factors. Children with severe asthma require significant resources including regular follow-up appointments with asthma education, written asthma action plan, and care by a multidisciplinary team. Management of pediatric severe asthma now includes emerging phenotypic-directed therapies; however, continued research is still needed to further study the long-term outcomes of pediatric severe asthma and its treatment.

Smokers who have children with asthma: Perceptions about child secondhand smoke exposure and tobacco use initiation and parental willingness to participate in child-focused tobacco interventions

OBJECTIVE

This study examined, among parents who smoke and have children with asthma, perceptions about child secondhand smoke exposure (SHSe), child tobacco use (TU) initiation, and parent willingness to participate in child-focused tobacco interventions.

METHODS

Participants were 300 caregivers who smoked and had a child with asthma (aged 10-14). Parents completed an online survey and self-reported perceptions about child SHSe elimination, child TU prevention, and willingness to participate in three types of interventions with and without their child (SHSe reduction intervention, tobacco prevention intervention, and the combination of the two). Correlates of perceptions and willingness were examined.

RESULTS

Parents who were ready to quit smoking and who reported home smoking bans (HSBs) were more motivated to eliminate SHSe (p < 0.05). Being white, younger, ready to quit, and having HSBs were associated with greater confidence to eliminate SHSe (p < 0.05). Parents with HSBs reported higher perceived importance about preventing child TU (p < 0.05). Parents were less confident about preventing male children from using tobacco (p = 0.001). Parents were highly willing to participate in all the described intervention approaches, with or without their child.

CONCLUSIONS

Parents were willing to participate in child-focused tobacco interventions, with or without their child with asthma, including interventions that address both child SHSe and TU prevention. This research demonstrates the acceptability of child-focused tobacco interventions among a high-risk population and may be a foundational step for intervention development.

Targeting transcription factor lysine acetylation in inflammatory airway diseases

Asthma and chronic obstructive pulmonary disease are inflammatory airway diseases for which alternative therapeutic strategies are urgently needed. Interestingly, HDAC inhibitors show anti-inflammatory effects in mouse models for these diseases. Here we explore underlying mechanisms that may explain these effects. In previous studies, effects of HDAC inhibitors on histone acetylation are often correlated with their effects on gene expression. However, effects of HDAC inhibitors on transcription factors and their acetylation status may be particularly important in explaining these effects. These effects are also cell type-specific. Recent developments (including chemoproteomics and acetylomics) allow for a more detailed understanding of the selectivity of HDAC inhibitors, which will drive their further development into applications in inflammatory airway diseases.

Severe asthma in children

Most children with asthma have their disease easily controlled if low-dose inhaled corticosteroids (ICSs) are regularly and correctly administered. If a child presents with asthma which is apparently resistant to therapy with high-dose ICS and other controllers, then they have problematic severe asthma. However, in light of the UK National Review of Asthma Deaths, definitions of severe asthma based solely on the levels of prescribed treatment are too narrow. A detailed assessment of all such children should be performed. First, the diagnosis of asthma should be confirmed, then co-morbidities assessed. Next, a nurse-led assessment further characterizes the problem, conventionally categorizing the child as either having difficult asthma or severe therapy-resistant asthma. Here, we reassess in particular the interactions between, and management of, these two categories, highlighting that this dichotomous classification may need reconsideration. We use bronchoscopy and an intramuscular steroid injection to determine if the child has steroid-resistant asthma, using a novel, multidomain approach because the adult definition does not apply to around half the children we see. Finally, we highlight some mechanistic data which have emerged from this protocol such as the absence of T-helper 2 (TH2) cytokines even in eosinophilic severe asthma and the potential role of the innate epithelial cytokine IL-33, novel data on lineage negative innate lymphoid cells, which we can measure in induced sputum, and demonstrating that intraepithelial neutrophils are associated with better, not worse asthma outcomes. Severe paediatric asthma is very different from severe asthma in adults, and approaches must not be uncritically extrapolated from adult disease to children.

Managing the pediatric patient with refractory asthma: a multidisciplinary approach

Children with asthma that is refractory to high levels of prescribed treatment are described as having problematic severe asthma. Those in whom persistent symptoms result from a failure of basic asthma management are described as having "difficult asthma", while those who remain symptomatic despite these factors having been addressed are described as having "severe therapy-resistant asthma" (STRA). The majority of children have difficult asthma; asthma that is poorly controlled because of a failure to get the basics of asthma management right. Modifiable factors including nonadherence to medication, persistent adverse environmental exposures, and psychosocial factors often contribute to poor control in these patients. As our skill in identifying and addressing modifiable factors has improved, we have found that a progressively smaller proportion of our clinic patients is categorized as having true STRA, resulting in an infrequent resort to escalation of treatment. Many of the modifiable factors associated with the diagnosis of difficult asthma can be identified in a general pediatric clinic. Characterization of more complex factors, however, requires the time, skill, and expertise of multiple health care professionals within the asthma multidisciplinary team. In this review, we will describe the structured approach adopted by The Royal Brompton Hospital in the management of the child with problematic severe asthma. We highlight the roles of members of the multidisciplinary team at various stages of assessment and focus on prominent themes in the identification and treatment of modifiable factors.

Advance of antioxidants in asthma treatment

Asthma is an allergic disease, characterized as a recurrent airflow limitation, airway hyperreactivity, and chronic inflammation, involving a variety of cells and cytokines. Reactive oxygen species have been proven to play an important role in asthma. The pathogenesis of oxidative stress in asthma involves an imbalance between oxidant and antioxidant systems that is caused by environment pollutants or endogenous reactive oxygen species from inflammation cells. There is growing evidence that antioxidant treatments that include vitamins and food supplements have been shown to ameliorate this oxidative stress while improving the symptoms and decreasing the severity of asthma. In this review, we summarize recent studies that are related to the mechanisms and biomarkers of oxidative stress, antioxidant treatments in asthma.

Allergy in severe asthma

It is well recognized that atopic sensitization is an important risk factor for asthma, both in adults and in children. However, the role of allergy in severe asthma is still under debate. The term 'Severe Asthma' encompasses a highly heterogeneous group of patients who require treatment on steps 4-5 of GINA guidelines to prevent their asthma from becoming 'uncontrolled', or whose disease remains 'uncontrolled' despite this therapy. Epidemiological studies on emergency room visits and hospital admissions for asthma suggest the important role of allergy in asthma exacerbations. In addition, allergic asthma in childhood is often associated with severe asthma in adulthood. A strong association exists between asthma exacerbations and respiratory viral infections, and interaction between viruses and allergy further increases the risk of asthma exacerbations. Furthermore, fungal allergy has been shown to play an important role in severe asthma. Other contributing factors include smoking, pollution and work-related exposures. The 'Allergy and Asthma Severity' EAACI Task Force examined the current evidence and produced this position document on the role of allergy in severe asthma.