Role of Epigenetics in the Pathogenesis, Treatment, Prediction, and Cellular Transformation of Asthma

Research on the Mechanism and Application of Acupuncture Therapy for Asthma: A Review

Asthma is a high-risk disease based on airway hyperresponsiveness (AHR). In this review, we found that there are many studies on clinical therapy for asthma that focus on the efficacy of acupuncture therapy and its mechanisms, including the functional connectivity of different brain regions, with the aid of functional magnetic resonance imaging (fMRI), immune responses/cell recognition (innate lymphoid cells and balance of Th1/Th2 and Treg/Th17), intracellular mechanism (autophagy, endoplasmic reticulum stress, and epigenetic alteration), and ligand-receptor/chemical signaling pathway (neurotransmitter, hormone, and small molecules). In this review, we summarized the clinical and experimental evidence for the mechanisms of acupuncture therapy in asthma to offer insights into drug discovery and clinical therapy. Given the paucity of clinical studies on the mechanisms of acupuncture in the treatment of asthma, this review notably included studies based on animal models to investigate the mechanisms of acupuncture in the treatment of asthma.

Time-dependent gene-environment interactions are essential drivers of asthma initiation and persistence

Asthma is a clinical syndrome caused by heterogeneous underlying mechanisms with some of them having a strong genetic component. It is known that up to 82% of atopic asthma has a genetic background with the rest being influenced by environmental factors that cause epigenetic modification(s) of gene expression. The interaction between the gene(s) and the environment has long been regarded as the most likely explanation of asthma initiation and persistence. Lately, much attention has been given to the time frame the interaction occurs since the host response (immune or biological) to environmental triggers, differs at different developmental ages. The integration of the time variant into asthma pathogenesis is appearing to be equally important as the gene(s)-environment interaction. It seems that, all three factors should be present to trigger the asthma initiation and persistence cascade. Herein, we introduce the importance of the time variant in asthma pathogenesis and emphasize the long-term clinical significance of the time-dependent gene-environment interactions in childhood.

Investigation of the Therapeutic Effect of Salbutamol on Endometriosis in a Mouse Model

Endometriosis is an immune chronic inflammatory disease, and there are currently no more effective drugs for treating endometriosis due to its unknown etiology. Salbutamol is a β2-adrenergic receptor (β2AR) agonist commonly used to treat asthma by selectively activating β2 receptors on airway smooth muscle and leukocytes, exerting bronchial dilation and synergistic anti-inflammatory effects. In recent years, β2AR agonists have been used in endometriosis studies, and we speculate that salbutamol may have a therapeutic effect on endometriosis. The purpose of this research was to explore the therapeutic effect of salbutamol on endometriosis mice. The mouse endometriosis model was established and treated with different doses of salbutamol. Endometrial lesions were harvested for pathological diagnosis, immunohistochemistry (IHC), Masson staining, and toluidine blue analysis. We found that the number and size of endometriotic lesions were all significantly decreased after 3 weeks of treatment with different doses of salbutamol on endometriosis model mice (P < 0.05). After Salbutamol treatment, the amount of mast cells (toluidine blue) and macrophages (F4/80) in the lesions as well as the expressions of interleukin (IL)-1β, tumor necrosis factor (TNF)-ɑ, platelet-derived growth factor subunit B (PDGFB), CD31, transforming growth factor (TGF)-β, Masson staining, BCL2, TUBB3, substance P (SP), and nerve growth factor (NGF) were significantly reduced (P < 0.05). These results suggested that salbutamol could effectively treat endometriosis in mice by reducing immune inflammatory cells and factors, angiogenesis, and fibrosis, increasing apoptosis of endometriotic lesions, and decreasing neurogenesis.

Advances in adrenergic receptors for the treatment of chronic obstructive pulmonary disease: 2023 update

INTRODUCTION

Strong scientific evidence and large experience support the use of β2-agonists for the symptomatic alleviation of COPD. Therefore, there is considerable effort in discovering highly potent and selective β2-agonists.

AREAS COVERED

Recent research on novel β2-agonists for the treatment of COPD. A detailed literature search was performed in two major databases (PubMed/MEDLINE and Scopus) up to September 2023."

EXPERT OPINION

Compounds that preferentially activate a Gs- or β-arrestin-mediated signaling pathway via β- adrenoceptors (ARs) are more innovative. Pepducins, which target the intracellular region of β2-AR to modulate receptor signaling output, have the most interesting profile from a pharmacological point of view. They stabilize the conformation of the β2-AR and influence its signaling by interacting with the intracellular receptor-G protein interface. New bifunctional drugs called muscarinic antagonist-β2 agonist (MABA), which have both muscarinic receptor (mAChR) antagonism and β2-agonist activity in the same molecule, are a new opportunity. However, all tested compounds have been shown to act predominantly as mAChR antagonists or β2-agonists. An intriguing idea is to utilize allosteric modulators that bind to β2-ARs at sites different than those bound by orthosteric ligands to augment or reduce the signaling transduced by the orthosteric ligand.

A pathogenic integrated view explaining the different endotypes of asthma and allergic disorders

The inflammation of allergic diseases is characterized by a complex interaction between type 2 and type 3 immune responses, explaining clinical symptoms and histopathological patterns. Airborne stimuli activate the mucosal epithelium to release a number of molecules impacting the activity of resident immune and environmental cells. Signals from the mucosal barrier, regulatory cells, and the inflamed tissue are crucial conditions able to modify innate and adaptive effector cells providing the selective homing of eosinophils or neutrophils. The high plasticity of resident T- and innate lymphoid cells responding to external signals is the prerequisite to explain the multiplicity of endotypes of allergic diseases. This notion paved the way for the huge use of specific biologic drugs interfering with pathogenic mechanisms of inflammation. Based on the response of the epithelial barrier, the activity of resident regulatory cells, and functions of structural non-lymphoid environmental cells, this review proposes some immunopathogenic scenarios characterizing the principal endotypes which can be associated with a precise phenotype of asthma. Recent literature indicates that similar concepts can also be applied to the inflammation of other non-respiratory allergic disorders. The next challenges will consist in defining specific biomarker(s) of each endotype allowing for a quick diagnosis and the most effective personalized therapy.

Androgen Plays a Potential Novel Hormonal Therapeutic Role in Th17 Cells Predominant Neutrophilic Severe Asthma by Attenuating BECs Regulated Th17 Cells Differentiation via MBD2 Expression

T helper 17 (Th17) cells subtype of non-T2 asthma is less responsive (resistant) to inhaled corticosteroids (ICS), so also called severe asthma. Methyl-CpG-binding domain protein 2 (MBD2) regulates the differentiation of the Th17 cells, showing the possibility of a therapeutic target in severe asthma. Androgen tends to show beneficial therapeutic effects and is a “hot research topic,” but its role in the differentiation and expression of Th17 cells via MBD2 is still unknown. The aim of this study was to evaluate how sex hormone interacts with MBD2 and affects the differentiation and expression of Th17 cells in severe asthma. Here, first, we measured the concentration of androgen, estrogen, and androgen estrogen ratio from subjects and correlated it with severe asthma status. Then, we established an animal model and bronchial epithelial cells (BECs) model of severe asthma to evaluate the role of MBD2 in the differentiation and expression of Th17 cells (IL-17), the therapeutic potential of sex hormones in severe asthma, and the effect of sex hormones in BECs regulated Th17 cells differentiation via MBD2 at the cellular level. Increased MBD2 expression and Th17 cells differentiation were noted in the animal and the BECs severe asthma models. Th17 cell differentiation and expression were MBD2 dependent. Androgen attenuated the differentiation of BECs regulated Th17 cells via MBD2 showing BECs as a therapeutic target of androgen, and these findings postulate the novel role of androgen in Th17 cells predominant neutrophilic severe asthma therapy through targeting MBD2.

Emerging Insights into the Impact of Air Pollution on Immune-Mediated Asthma Pathogenesis

PURPOSE OF REVIEW

Increases in ambient levels of air pollutants have been linked to lung inflammation and remodeling, processes that lead to the development and exacerbation of allergic asthma. Conventional research has focused on the role of CD4+ T helper 2 (TH2) cells in the pathogenesis of air pollution-induced asthma. However, much work in the past decade has uncovered an array of air pollution-induced non-TH2 immune mechanisms that contribute to allergic airway inflammation and disease.

RECENT FINDINGS

In this article, we review current research demonstrating the connection between common air pollutants and their downstream effects on non-TH2 immune responses emerging as key players in asthma, including PRRs, ILCs, and non-TH2 T cell subsets. We also discuss the proposed mechanisms by which air pollution increases immune-mediated asthma risk, including pre-existing genetic risk, epigenetic alterations in immune cells, and perturbation of the composition and function of the lung and gut microbiomes. Together, these studies reveal the multifaceted impacts of various air pollutants on innate and adaptive immune functions via genetic, epigenetic, and microbiome-based mechanisms that facilitate the induction and worsening of asthma.

Effect of Routine Therapy Assisted by Physical Exercise on Pulmonary Function in Patients with Asthma in Stable Stage: A Systematic Review and Meta-analysis of Randomized Clinical Trials

Objective

This study is aimed at investigating the efficacy of physical exercise-assisted routine therapy on the pulmonary function of patients with stable asthma to provide clinical evidence and data support to guide disease management.

Methods

Randomized controlled clinical trials of drug therapy and/or physical exercise for patients with stable asthma were retrieved from the China National Knowledge Infrastructure (CNKI), Wanfang database, Embase, PubMed, and Web of Science database. The studies published between January 2000 and June 2021 that met the criteria were included, and corresponding data were extracted. The meta-analysis was performed using the statistical software Stata 16.0. Statistical pooled effect sizes and 95% confidence intervals were calculated using a random-effects or fixed-effects model, as funnel plots were made with Begg's rank correlation method to evaluate publication bias.

Result

This meta-analysis included 14 randomized controlled studies. Physical exercise-assisted treatment (experiment group) or routine therapy was associated with significantly elevated levels of forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) (P < 0.05). As for the peak expiratory flow (PEF) level (P < 0.05), its level was significantly increased with physical exercise-assisted therapy compared with the conventional approach (P > 0.05). Subgroup analysis indicated that the FVC level in the experimental group was higher than that in the control group (P < 0.05) regardless of the adoption of aerobic exercise/anaerobic exercise. In regard to the FEV1 and PEE levels, aerobic exercise was associated with elevated levels in the experimental group (P < 0.05), while no significant difference in anaerobic exercise between both groups was observed (P > 0.05). Further, FEV1, FVC, and PEF levels in the experimental group were higher than those receiving conventional treatment in the control group (P < 0.05).

Conclusion

Routine treatment combined with physical exercise could improve the levels of FEV1, FVC, and PEF in patients with bronchial asthma in the nonacute attack stage and enhance pulmonary functions. As a safe and efficient adjuvant therapy, physical exercise can contribute to an improved prognosis and quality of life for patients with asthma.

Sirtuins-Novel Regulators of Epigenetic Alterations in Airway Inflammation

Histone modification is an important epigenetic alteration, and histone deacetylases are involved in the occurrence and development of various respiratory diseases. Sirtuins (SIRTs) have been demonstrated to play an important role in the formation and progression of chronic inflammatory diseases of the respiratory tract. SIRTs participate in the regulation of oxidative stress and inflammation and are related to cell structure and cellular localization. This paper summarizes the roles and mechanisms of SIRTs in airway inflammation and describes the latest research on SIRT modulators, aiming to provide a theoretical basis for the study of potential epigenetic alteration-inducing drug targets.

Biased β-Agonists Favoring Gs over β-Arrestin for Individualized Treatment of Obstructive Lung Disease

Signals from G-protein-coupled receptors (GPCRs) are the most frequently targeted pathways of currently prescribed therapeutics. Rather than being a simple switch, it is now evident that a given receptor can directly initiate multiple signals, and biasing to achieve signal selectivity based on agonist structure is possible. Biased agonists could direct therapeutically favorable pathways while avoiding counterproductive or adverse reaction pathways. For obstructive lung diseases, β2-adrenergic receptor (β2AR) agonists act at these receptors on airway smooth muscle (ASM) cells to open the airways by relaxing ASM, improving airflow and morbidity. However, these receptors signal to the G protein Gs (increasing cAMP and promoting relaxation), but also to β-arrestin (promoting desensitization and a loss of effectiveness). Indeed, β-agonist use is associated with adverse events in asthma pathogenesis and clinical outcomes which are related to desensitization. β-agonists favoring Gs coupling over β-arrestin binding would provide a means of tailoring bronchodilator therapy. In this review, we show how combinatorial methods with a 40 million compound agnostic library led to a new class of biased β-agonists that do not desensitize, providing an opportunity to personalize therapy in patients who experience poor efficacy or adverse effects from traditional balanced agonists.

Multi-Omics Profiling Approach to Asthma: An Evolving Paradigm

Asthma is a complex multifactorial and heterogeneous respiratory disease. Although genetics is a strong risk factor of asthma, external and internal exposures and their interactions with genetic factors also play important roles in the pathophysiology of asthma. Over the past decades, the application of high-throughput omics approaches has emerged and been applied to the field of asthma research for screening biomarkers such as genes, transcript, proteins, and metabolites in an unbiased fashion. Leveraging large-scale studies representative of diverse population-based omics data and integrating with clinical data has led to better profiling of asthma risk. Yet, to date, no omic-driven endotypes have been translated into clinical practice and management of asthma. In this article, we provide an overview of the current status of omics studies of asthma, namely, genomics, transcriptomics, epigenomics, proteomics, exposomics, and metabolomics. The current development of the multi-omics integrations of asthma is also briefly discussed. Biomarker discovery following multi-omics profiling could be challenging but useful for better disease phenotyping and endotyping that can translate into advances in asthma management and clinical care, ultimately leading to successful precision medicine approaches.

Emerging Roles of Non-Coding RNAs in Childhood Asthma

Asthma is a chronic airway inflammatory disease in children characterized by airway inflammation, airway hyperresponsiveness and airway remodeling. Childhood asthma is usually associated with allergy and atopy, unlike adult asthma, which is commonly associated with obesity, smoking, etc. The pathogenesis and diagnosis of childhood asthma also remains more challenging than adult asthma, such as many diseases showing similar symptoms may coexist and be confused with asthma. In terms of the treatment, although most childhood asthma can potentially be self-managed and controlled with drugs, approximately 5-10% of children suffer from severe uncontrolled asthma, which carries significant health and socioeconomic burdens. Therefore, it is necessary to explore the pathogenesis of childhood asthma from a new perspective. Studies have revealed that non-coding RNAs (ncRNAs) are involved in the regulation of respiratory diseases. In addition, altered expression of ncRNAs in blood, and in condensate of sputum or exhalation affects the progression of asthma via regulating immune response. In this review, we outline the regulation and pathogenesis of asthma and summarize the role of ncRNAs in childhood asthma. We also hold promise that ncRNAs may be used for the development of biomarkers and support a new therapeutic strategy for childhood asthma.

Role of Sex Hormones at Different Physiobiological Conditions and Therapeutic Potential in MBD2 Mediated Severe Asthma

Sex hormone has become a “hot topic” to evaluate the hormonal therapeutic potential in severe asthma. Th17 cell is one of the main influencing factors involved in the pathogenesis of severe asthma, hence also called as kernel of severe asthma, and Th17 subtype of non-T2 asthma is less responsive (resistance) to inhaled corticosteroid (ICS), so severe in nature. Methyl-CpG binding domain protein 2 (MBD2) is overexpressed and regulates the Th17 differentiation, showing the possibility of therapeutic target in treating Th17 mediated severe asthma. Sex hormone fluctuates at the different physiobiological conditions of the human body and affects the asthma pathobiology showing its role in asthma prevalence, severity, remission, and therapy. This review briefly overviews the sex hormones, their influence in asthma at the different physiobiological conditions of human body, and MBD2 severe asthma connection with the possible therapeutic potential of sex steroids in MBD2 mediated Th17 predominant severe asthma. Male sex hormone tends to show a beneficial effect and possibly downregulates the expression of Th17 cells via regulating MBD2 through a mechanism distinct from corticosteroid treatment and guides us towards discovery of new therapeutic agent, reduces the asthma-related complications, and promotes long-term survival by lowering the risk of therapy-resistant issues of old age severe asthma.