Which biomarkers are effective for identifying Th2-driven inflammation in asthma?

Identifying key genes and functionally enriched pathways in Th2-high asthma by weighted gene co-expression network analysis

Background

Asthma is a chronic lung disease characterized by reversible inflammation of the airways. The imbalance of Th1/Th2 cells plays a significant role in the mechanisms of asthma. The aim of this study was to identify asthma-related key genes and functionally enriched pathways in a Th2-high group by using weighted gene coexpression network analysis (WGCNA).

Methods

The gene expression profiles of GSE4302, which included 42 asthma patients and 28 controls, were selected from the Gene Expression Omnibus (GEO). A gene network was constructed, and genes were classified into different modules using WGCNA. Gene ontology (GO) was performed to further explore the potential function of the genes in the most related module. In addition, the expression profile and diagnostic capacity (ROC curve) of hub genes of interest were verified by dataset GSE67472.

Results

In dataset GSE4302, subjects with asthma were divided into Th2-high and Th2-low groups according to the expression of the SERPINB2, POSTN and CLCA1 genes. A weighted gene coexpression network was constructed, and genes were classified into 7 modules. Among them, the red module was most closely associated with Th2-high asthma, which contained 60 genes. These genes were significantly enriched in different biological processes and molecular functions. A total of 8 hub genes (TPSB2, CPA3, ITLN1, CST1, SERPINB10, CEACAM5, CHD26 and P2RY14) were identified, and the expression levels of these genes (except TPSB2) were confirmed in dataset GSE67472. ROC curve analysis validated that the expression of these 8 genes exhibited excellent diagnostic efficiency for Th2-high asthma and Th2-low asthma.

Conclusions

The study provides a novel perspective on Th2-high asthma by WGCNA, and the hub genes and potential pathways involved may be beneficial for the diagnosis and management of Th2-high asthma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01241-9.

Triterpenoid compound betulin attenuates allergic airway inflammation by modulating antioxidants, inflammatory cytokines and tissue transglutaminase in ovalbumin-induced asthma mice model

OBJECTIVES

This study hypothesized that to analyse the anti-inflammatory effect of triterpenoid compound betulin in ovalbumin (OVA)-induced asthmatic mice.

METHODS

In this study, betulin was intraperitoneally administered in OVA-challenged and sensitized mice. The effect of betulin on inflammatory cells, lung function, reactive oxygen species (ROS) production, antioxidants status, oxidative stress markers, serum IgE level and inflammatory cytokines status in BALF was examined by enzyme-linked immunosorbent assay. The expression of tTG, TGF-β1, MMP-9 and TIMP-1 in lung tissue was scrutinized by RT-qPCR analysis, and the expression of TREM-1, p-IκB-α and NF-κBp65 proteins in lung tissue was examined by western blot analysis.

KEY FINDINGS

We found that the betulin treatment has effectively attenuated the proliferation of inflammatory cells, reduced the ROS generation, elevated the antioxidant enzymes and attenuated the level of oxidative markers in asthma induced mice. Moreover, reduced the level of serum IgE and pro-inflammatory cytokines, and increased the anti-inflammatory cytokine IFN-γ. Betulin treatment down-regulated the expression of MMP-9, tTG and TGF-β1 genes; moreover, betulin treatment effectively down-regulated the TREM-1, p-IκB-α and NF-κBp65 proteins level in lung.

CONCLUSION

Betulin exhibited effective anti-asthmatic activity by attenuating the accumulation of inflammatory cells, expression of tTG, TGF-β1 and MMP-9 genes in lung tissue.

The current and future role of biomarkers in type 2 cytokine-mediated asthma management

Assessment and management of asthma is complicated by the heterogeneous pathophysiological mechanisms that underlie its clinical presentation, which are not necessarily reflected in standardized management paradigms and which necessitate an individualized approach to treatment. This is particularly important with the emerging availability of a variety of targeted forms of therapy that may only be appropriate for use in particular patient subgroups. The identification of biomarkers can potentially aid diagnosis and inform prognosis, help guide treatment decisions and allow clinicians to predict and monitor response to treatment. Biomarkers for asthma have been identified from a variety of sources, including airway, exhaled breath and blood. Biomarkers from exhaled breath include fractional exhaled nitric oxide, measurement of which can help identify patients most likely to benefit from inhaled corticosteroids and targeted anti-immunoglobulin E therapy. Biomarkers measured in blood are relatively non-invasive and technically more straightforward than those measured from exhaled breath or directly from the airway. The most well established of these are the blood eosinophil count and serum periostin, both of which have demonstrated utility in identifying patients most likely to benefit from targeted anti-interleukin and anti-immunoglobulin E therapies, and in monitoring subsequent treatment response. For example, serum periostin appears to be a biomarker for responsiveness to inhaled corticosteroid therapy and may help identify patients as suitable candidates for anti-IL-13 treatment. The use of biomarkers can therefore potentially help avoid unnecessary morbidity from high-dose corticosteroid therapy and allow the most appropriate and cost-effective use of targeted therapies. Ongoing clinical trials are helping to further elucidate the role of established biomarkers in routine clinical practice, and a range of other circulating novel potential biomarkers are currently being investigated in the research setting.

Lebrikizumab in the treatment of asthma

INTRODUCTION

Severe asthma continues to be a major clinical problem despite the availability of effective asthma medications such as inhaled corticosteroids. Several targeted biologic therapies are emerging to treat patients with severe asthma. Areas Covered: This review provides an update of information on lebrikizumab, a novel monoclonal antibody that targets IL-13 and is currently in advanced stages of development. It describes the role of IL-13, a key effector cytokine in Type 2 (T2) airway inflammation in asthma and discusses the results of recent phase 2 trials investigating lebrikizumab's efficacy and safety in patients with severe asthma. Furthermore, it provides insight into the current ongoing trials with lebrikizumab and outlines future research needs. Expert Opinion: Several emerging therapeutic targets have been identified for patients with severe asthma. By specifically targeting IL-13, lebrikizumab has the potential to block several downstream signals that play a role in disease progression including airway inflammation, mucous hypersecretion and airway remodeling. The effects of lebrikizumab have been more marked in individuals with high serum periostin levels which reflect underlying IL-13 activity and T2 airway inflammation. Ongoing trials with lebrikizumab aim to further examine its long-term safety and efficacy in a larger population and explore its effects on airway inflammation and function.

Loki zupa (Luooukezupa) decoction reduced airway inflammation in an OVA-induced asthma mouse model

Background

Loki zupa (Luooukezupa) decoction, consisting of the roots of Hyssopuscuspidatus Boriss (Shenxiangcao) and Irishalophila Pall root (Yuanweigen), is commonly used in Uygur medicine to treat asthma. However, the mode of action of this material has yet to be elucidated. This study aims to investigate the effects of Loki zupa decoction on the airway inflammation of an ovalbumin (OVA)-induced asthma mouse model.

Methods

Mice were divided into normal control (NC), asthma (A), high, medium and low doses of Loki zupa decoction (L 14.0, L 7.0, L 3.5), water extract (LW), n-butanol extract (LN), ethyl acetate extract (LE) and dexamethasone (DEX) groups. Antiasthmatic model was induced by OVA sensitization and challenged using BALB/c mice. Airway hyperresponsiveness (AHR) toward methacholine (Mch) was assessed using Buxco equipment. Lung inflammation was measured by hematoxylin and eosin staining and bronchoalveolar lavage fluid (BALF) cell count and classification. Inflammatory cytokines in BALF and serum were analyzed by Bio-Plex assay, and mRNA levels were investigated by qPCR analysis. The roots of H. Boriss (250 g) and I. Pall (250 g) were decocted, concentrated and diluted to 14.0, 7.0 and 3.5 g crude herb/kg body weight. The LW, LN and LE of the Loki zupa decoction were prepared and diluted to a dose equivalent to 7 g of crude herb/kg body weight.

Results

Loki zupa decoction and its extracts significantly attenuated the AHR towards Mch (all P < 0.05). Treatment with Loki zupa decoction and its extracts relieved the infiltration of inflammatory cells in and around the airways, and reduced the total white blood cell (all P < 0.05), neutrophil (all P < 0.05), monocyte (all P < 0.05) and eosinophil (all P < 0.05) counts in the BALF. The BALF samples collected from the mice treated with the Loki zupa decoction and its extracts had lower levels of IL-1β (all P < 0.05), TNF-α (all P < 0.05), IL-2 (all P < 0.05), IL-4 (P = 0.047) and IL-5 (all P < 0.05). The serum samples of these mice also had lower IL-1β (all P < 0.05), TNF-α (all P < 0.05), IL-4 (all P < 0.05) and IL-5 (all P < 0.05) levels and higher levels of IFN-γ (P < 0.001) compared with the OVA-induced asthma mouse model. qPCR analysis revealed that Loki zupa decoction and its extracts inhibited mRNA expression of IL-4 (all P < 0.05), IL-5 (all P < 0.05) and IL-13 (all P < 0.05) and promoted mRNA expression of IFN-γ (all P < 0.05) in asthmatic mice.

Conclusion

Loki zupa decoction reduced AHR, attenuated airway inflammation, promoted Th1 and suppressed Th2 cell functions in an OVA-induced asthma mouse model.

Electronic supplementary material

The online version of this article (doi:10.1186/s13020-016-0094-9) contains supplementary material, which is available to authorized users.

Periostin - A Novel Systemic Biomarker for Eosinophilic Airway Inflammation: A Case Control Study

INTRODUCTION

Chronic airway inflammation and remodelling are fundamental features of asthma. The molecular phenotypes in asthma are Th2 high and Th2 low. Serum periostin is a biomarker which aid in understanding Th2 high eosinophilic asthma.

AIM

The present study aimed to identify whether or not serum periostin is a systemic biomarker for eosinophilic airway inflammation in asthmatics.

MATERIALS AND METHODS

The study was designed as a prospective, case control study. Patients who presented with consistent symptoms of asthma and confirmed by spirometry with reversibility were the cases. The controls were healthy subjects who had no history of lung disease with normal lung function. The sputum and blood samples were collected from both the groups. Sputum eosinophils, Absolute Eosinophil Counts (AEC) and serum periostin levels were compared between the groups.

RESULTS

The study comprised of 101 participants in which 30 were controls and 71 were cases. In the study group, mean post FEV1 was 64.45. There was a positive correlation of sputum eosinophils with severity of obstruction. The ROC curve analysis showed the cut-off value of 24.556 for serum periostin with the p-value of <0.001. As the severity of obstruction increased, the serum periostin levels were also found to be increased. Serum periostin had a sensitivity and specificity of 97.18% and 86.67% with a diagnostic accuracy of 94.06%.

CONCLUSION

Serum periostin appears to be a more sensitive tool for detection of airflow limitation in asthmatic patients with a Th2 high eosinophilic phenotype when compared to AEC and sputum eosinophils.

A review of standard pharmacological therapy for adult asthma – Steps 1 to 5

The aim of pharmacological therapy for asthma is to improve symptoms and lung function and minimize the risk of asthma attacks. The intensity of treatment is based on the level of asthma control and the potential risk of future deterioration. In the British asthma guidelines, treatments are divided into steps 1 to 5, with each step signifying a need for an increase in therapy in response to symptoms or to prevent exacerbations. Treatments comprise of inhaled or systemic medications. Inhaled therapy includes short-acting and long-acting medication to improve symptoms and inhaled corticosteroids that reduce airway inflammation. Systemic treatments include medications that act on specific biological pathways, such as the leukotriene or immunoglobulin E pathways, or systemic corticosteroids. In choosing a particular therapy, treatment benefits are balanced by the potential risks of medication-related adverse effects. This review will provide a practical guide to the key pharmacological therapies for adult asthma at steps 1 to 5 based on British guidelines and consider future options for new treatments.

Changes in immunological profile as a function of urbanization and lifestyle

Differences in lifestyle and break with natural environment appear to be associated with changes in the immune system resulting in various adverse health effects. Although genetics can have a major impact on the immune system and disease susceptibility, the contribution of environmental factors is thought to be substantial. Here, we investigated the immunological profile of healthy volunteers living in a rural and an urban area of a developing African country (Senegal), and in a European country (the Netherlands). Using flow cytometry, we investigated T helper type 1 (Th1), Th2, Th17, Th22 and regulatory T cells, as well as CD4(+) T-cell and B-cell activation markers, and subsets of memory T and B cells in the peripheral blood. Rural Senegalese had significantly higher frequencies of Th1, Th2 and Th22 cells, memory CD4(+) T and B cells, as well as activated CD4(+) T and B cells compared with urban Senegalese and urban Dutch people. Within the Senegalese population, rural paritcipants displayed significantly higher frequencies of Th2 and Th22 cells, as well as higher pro-inflammatory and T-cell activation and memory profiles compared with the urban population. The greater magnitude of immune activation and the enlarged memory pool, together with Th2 polarization, seen in rural participants from Africa, followed by urban Africans and Europeans suggest that environmental changes may define immunological footprints, which could have consequences for disease patterns in general and vaccine responses in particular.

Protective effects of the polyphenol sesamin on allergen-induced T(H)2 responses and airway inflammation in mice

Allergic asthma is a lifelong airway condition that affects people of all ages. In recent decades, asthma prevalence continues to increase globally, with an estimated number of 250,000 annual deaths attributed to the disease. Although inhaled corticosteroids and β-adrenergic receptor agonists are the primary therapeutic avenues that effectively reduce asthma symptoms, profound side effects may occur in patients with long-term treatments. Therefore, development of new therapeutic strategies is needed as alternative or supplement to current asthma treatments. Sesamin is a natural polyphenolic compound with strong anti-oxidative effects. Several studies have reported that sesamin is effective in preventing hypertension, thrombotic tendency, and neuroinflammation. However, it is still unknown whether sesamin can reduce asthma-induced allergic inflammation and airway hyperresponsiveness (AHR). Our study has revealed that sesamin exhibited significant anti-inflammatory effects in ovalbumin (OVA)-induced murine asthma model. We found that treatments with sesamin after OVA sensitization and challenge significantly decreased expression levels of interleukin-4 (IL-4), IL-5, IL-13, and serum IgE. The numbers of total inflammatory cells and eosinophils in BALF were also reduced in the sesamin-treated animals. Histological results demonstrated that sesamin attenuated OVA-induced eosinophil infiltration, airway goblet cell hyperplasia, mucus occlusion, and MUC5AC expression in the lung tissue. Mice administered with sesamin showed limited increases in AHR compared with mice receiving vehicle after OVA challenge. OVA increased phosphorylation levels of IκB-α and nuclear expression levels of NF-κB, both of which were reversed by sesamin treatments. These data indicate that sesamin is effective in treating allergic asthma responses induced by OVA in mice.