Year in review 2015: Asthma and chronic obstructive pulmonary disease

Association of two polymorphisms of miRNA-146a rs2910164 (G > C) and miRNA-499 rs3746444 (T > C) with asthma: a meta-analysis

OBJECTIVE

To conduct a meta-analysis to determine the association between two single nucleotide polymorphisms (SNPs) miRNA146a rs2910164 (G > C) and miRNA-499 rs3746444 (T > C) and asthma risk.

DATA SOURCES

PubMed and Embase (updated May 17, 2019).

KEYWORDS

(microRNA OR microRNAs) AND (polymorphism OR polymorphisms) AND (Asthmas OR Bronchial Asthma OR Asthma, Bronchial).

RESULTS

Six eligible case-control studies (2441 asthma cases and 3044 controls) met our inclusion criteria. A trend of increased asthma risk was indicated by the heterozygote model (miR-499: TC versus TT, OR = 1.38, 95% CI = 1.06-1.79, P < 0.01) and the dominant model (miR-499: TC + CC versus TT, OR = 1.60, 95% CI = 1.07-2.39, P < 0.01) of miRNA-499 rs3746444. Polymorphisms rs2910164 in miRNA-146a of the allele model (miR-146a: C versus G, OR = 0.84, 95% CI = 0.74-0.96, P = 0.238), homozygote model (miR-146a: CC versus GG, OR = 0.68, 95% CI = 0.51-0.91, P = 0.213), recessive model (miR-146a: CC versus GC + GG, OR = 0.75, 95% CI = 0.60-0.94, P = 0.149) indicated a decreased risk of asthma.

CONCLUSIONS

The miR-499 rs3746444 (T > C) polymorphism is associated with asthma susceptibility and miRNA-146a rs2910164 (G > C) polymorphism has a protective role against susceptibility to asthma.

Characterizing Pharmacokinetic-Pharmacodynamic Relationships and Efficacy of PI3Kδ Inhibitors in Respiratory Models of TH2 and TH1 Inflammation

We leveraged a clinical pharmacokinetic (PK)/pharmacodynamics (PD)/efficacy relationship established with an oral phosphatidylinositol 3-kinase (PI3K)δ inhibitor (Idelalisib) in a nasal allergen challenge study to determine whether a comparable PK/PD/efficacy relationship with PI3Kδ inhibitors was observed in preclinical respiratory models of type 2 T helper cell (TH2) and type 1 T helper cell (TH1) inflammation. Results from an in vitro rat blood basophil (CD63) activation assay were used as a PD biomarker. IC₅₀ values for PI3Kδ inhibitors, MSD-496486311, MSD-126796721, Idelalisib, and Duvelisib, were 1.2, 4.8, 0.8, and 0.5 μM. In the ovalbumin Brown Norway TH2 pulmonary inflammation model, all PI3Kδ inhibitors produced a dose-dependent inhibition of bronchoalveolar lavage eosinophils (maximum effect between 80% and 99%). In a follow-up experiment designed to investigate PK attributes [maximum (or peak) plasma concentration (Cmax), area under the curve (AUC), time on target (ToT)] that govern PI3Kδ efficacy, MSD-496486311 [3 mg/kg every day (QD) and 100 mg/kg QD] produced 16% and 93% inhibition of eosinophils, whereas doses (20 mg/kg QD, 10 mg/kg twice per day, and 3 mg/kg three times per day) produced 54% to 66% inhibition. Our profiling suggests that impact of PI3Kδ inhibitors on eosinophils is supported by a PK target with a ToT over the course of treatment close to the PD IC₅₀ rather than strictly driven by AUC, Cmax, or Cmin (minimum blood plasma concentration) coverage. Additional studies in an Altenaria alternata rat model, a sheep Ascaris-sensitive sheep model, and a TH1-driven rat ozone exposure model did not challenge our hypothesis, suggesting that an IC₅₀ level of TE (target engagement) sustained for 24 hours is required to produce efficacy in these traditional models. We conclude that the PK/PD observations in our animal models appear to align with clinical results associated with a TH2 airway disease.

Interactions between polycyclic aromatic hydrocarbons and epoxide hydrolase 1 play roles in asthma

Asthma, as one of the most common chronic diseases in children and adults, is a consequence of complex gene-environment interactions. Polycyclic aromatic hydrocarbons (PAHs), as a group of widespread environmental organic pollutants, are involved in the development, triggering and pathologic changes of asthma. Various previous studies reported the critical roles of PAHs in immune changes, oxidative stress and environment-gene interactions of asthma. EPHX1 (the gene of epoxide hydrolase 1, an enzyme mediating human PAH metabolism) had a possible association with asthma by influencing PAH metabolism. This review summarized that (1) the roles of PAHs in asthma-work as risk factors; (2) the possible mechanisms involved in PAH-related asthma-through immunologic and oxidative stress changes; (3) the interactions between PAHs and EPHX1 involved in asthma-enzymatic activity of epoxide hydrolase 1, which affected by EPHX1 genotypes/SNPs/diplotypes, could influence human PAH metabolism and people's vulnerability to PAH exposure. This review provided a better understanding of the above interactions and underlying mechanisms for asthma which help to raise public's concern on PAH control and develop strategies for individual asthma primary prevention.

Association of the miR-196a2, miR-146a, and miR-499 Polymorphisms with Asthma Phenotypes in a Korean Population

BACKGROUND

MicroRNAs (miRNAs) modulate expressions of inflammatory genes, thereby regulating inflammatory responses. Single nucleotide polymorphisms (SNPs) in miRNAs could affect their efficiency in binding to messenger RNAs (mRNAs).

OBJECTIVE

We investigated the associations of miRNA SNPs with asthma phenotypes. miR-196a2 (rs11614913 T>C), miR-146a (rs2910164 C>G), and miR-499 (rs3746444 A>G) were genotyped in 347 asthma patients and 172 normal healthy controls (NCs).

RESULTS

The CT/CC genotype of miR-196a2 rs11614913 was associated with eosinophilic asthma (p = 0.004) and a higher sputum eosinophil count compared with the TT genotype (p = 0.003). The CG/GG genotype of miR-146a rs2910164 tended to be associated with higher bronchial hyperresponsiveness to methacholine (PC₂₀) compared with the CC genotype. The AG/GG genotype of miR-499 rs3746444 was associated with higher predicted values of forced expiratory volume in 1 s (%FEV₁) compared with the AA genotype (p = 0.008).

CONCLUSIONS

Genetic polymorphisms in miR-196a2, miR-146a, and miR-499 could be potential biomarkers for asthma phenotypes and targets for asthma treatments in a Korean population.

A Systems Approach to Refine Disease Taxonomy by Integrating Phenotypic and Molecular Networks

The International Classification of Diseases (ICD) relies on clinical features and lags behind the current understanding of the molecular specificity of disease pathobiology, necessitating approaches that incorporate growing biomedical data for classifying diseases to meet the needs of precision medicine. Our analysis revealed that the heterogeneous molecular diversity of disease chapters and the blurred boundary between disease categories in ICD should be further investigated. Here, we propose a new classification of diseases (NCD) by developing an algorithm that predicts the additional categories of a disease by integrating multiple networks consisting of disease phenotypes and their molecular profiles. With statistical validations from phenotype-genotype associations and interactome networks, we demonstrate that NCD improves disease specificity owing to its overlapping categories and polyhierarchical structure. Furthermore, NCD captures the molecular diversity of diseases and defines clearer boundaries in terms of both phenotypic similarity and molecular associations, establishing a rational strategy to reform disease taxonomy.

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The International Classification of Diseases (ICD) lags behind the current molecular characteristics of disease.

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We quantified the limitations (specificity and blurred boundary) of ICD with integrated phenotypic and molecular profiles.

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An integrative disease network integrating phenotypic and genotypic profiles proposes a refined disease category framework.

Disease taxonomy is one of the foundations of medical science and healthcare solutions. The most widely used disease taxonomy in clinical settings is the International Classification of Diseases (ICD), a system established >100 years ago and maintained by the World Health Organization to track disease incidence. It is well recognized that ICD, which is based on clinical observations, largely lags behind the molecular achievements of this medical big data era. We quantified the limitations of ICD using integrated phenotypic and molecular profiles and proposed a refined disease taxonomy with possible applications for precision medicine.

Efficacy of salmeterol and formoterol combination treatment in mice with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a severe lung disease characterized by progressive airflow limitation. Salmeterol and formoterol are two commonly used drugs in COPD therapy, which act as β2-receptor agonists. In the current study, a mouse model of COPD induced by airway lipopolysaccharide inhalation was established. The therapeutic efficacy of salmeterol and formoterol co-treatment was investigated in this model over a 56-day-long observation period. It was also identified that functional residual capacity and inspiratory resistance were significantly improved after salmeterol and/or formoterol treatment compared with the control group (all P<0.01). Furthermore, histological staining of lung tissue samples indicated that inflammation, thickening of the smooth muscle, goblet cell hyperplasia and pulmonary small vessel obstruction were reduced in the mice treated with salmeterol and/or formoterol, suggesting that salmeterol and formoterol were beneficial for ongoing airway and blood vessel remodeling in mice with COPD. The most common treatment-associated adverse events were hypertension and proteinuria. In conclusion, combined salmeterol and formoterol treatment was more effective compared with either single agent, suggesting that salmeterol and formoterol combined treatment has therapeutic value for the clinical treatment of patients with COPD.

The clinical profile of benralizumab in the management of severe eosinophilic asthma

Despite several therapeutic choices, 10–20% of patients with severe uncontrolled asthma do not respond to maximal best standard treatments, leading to a healthcare expenditure of up to 80% of overall costs for asthma. Today, there are new important therapeutic strategies, both pharmacological and interventional, that can result in improvement of severe asthma management, such as omalizumab, bronchial thermoplasty and other biological drugs, for example, mepolizumab, reslizumab and benralizumab. The availability of these new treatments and the increasing knowledge of the different asthmatic phenotypes and endotypes makes correct patient selection increasingly complex and important. In this article, we discuss the features of benralizumab compared with other anti-interleukin-5 biologics and omalizumab, the identification of appropriate patients, the safety profile and future developments.

Correlation of 5-HTT, BDNF and NPSR1 gene polymorphisms with anxiety and depression in asthmatic patients

Asthmatic patients are known to have a higher risk of anxiety and depression. In the present study, we aimed to explore the association of serotonin transporter (5-HTT), brain-derived neurotrophic factor (BDNF) and neuropeptide S receptor 1 (NPSR1) gene polymorphisms with anxiety and depression in asthmatic patients. This was a cross-sectional study conducted on 143 asthmatic patients and 175 healthy volunteers. Of the asthmatic patients, 49 suffered from anxiety and 12 exhibited signs of depression. Patients with a lower level of education were more prone to depression. Both anxiety and depression were associated with poor asthma control as evaluated by the Asthma Control Test (ACT) score. The association of single nucleotide polymorphisms of BDNF, NPSR1 and 5-HTT with anxiety and depression in asthamtic patients was evaluated. The distribution of 5-HTT gene polymorphisms in the healthy group, the group with asthma but without anxiety, and the group with asthma and anxiety had significant differences. Females with asthma and anxiety were more prone to BDNF polymorphism. Also, BDNF gene distribution exhibited significant differences among those in the healthy group, the group with asthma but no depression, and the group with asthma and depression; however, NPSR1 gene distribution did not vary greatly between the groups. The anxiety score was significantly affected by the interaction between 5-HTT (LL, S⁺) and BDNF (A⁺, GG) (H=5.99, P=0.015). The depression score was significantly affected by the interaction between BDNF (A⁺, GG) and NPSR1 (AA, T⁺). We noted that both anxiety and depression led to poor asthma control. The interaction between 5-HTT (LL) and BDNF (A⁺) increased the risk of anxiety, and the interaction between BDNF (A⁺, GG) and NPSR1 (AA, T⁺) increased the risk of depression in asthmatic patients.

Pathophysiologic Role of Autophagy in Human Airways

Lung diseases are among the most common and widespread disorders worldwide. They refer to many different pathological conditions affecting the pulmonary system in acute or chronic forms, such as asthma, chronic obstructive pulmonary disease, infections, cystic fibrosis, lung cancer and many other breath complications. Environmental, epigenetic and genetic co-factors are responsible for these pathologies that can lead to respiratory failure, and, even, ultimately death. Increasing evidences have highlighted the implication of the autophagic pathways in the pathogenesis of lung diseases and, in some cases, the deregulated molecular mechanisms underlying autophagy may be considered as potential new therapeutic targets. This chapter summarizes recent advances in understanding the pathophysiological functions of autophagy and its possible roles in the causation and/or prevention of human lung diseases.