Chloroquine Attenuates Asthma Development by Restoring Airway Smooth Muscle Cell Phenotype Via the ROS-AKT Pathway

Oxidative stress in asthma pathogenesis: mechanistic insights and implications for airway smooth muscle dysfunction

Airway smooth muscle (ASM) dysfunction is a key factor in the narrowing of airways in asthma patients, characterized by excessive secretion of inflammatory factors, increased mass, and amplified contractile responses. These pathological features are instrumental in the propagation of airway inflammation, structural remodeling, and the escalation of airway hyperresponsiveness (AHR), which are also principal factors underlying the limitations of current therapeutic strategies. In asthmatic ASM, an imbalance between oxidant production and antioxidant defenses culminates in oxidative stress, which is involved in the excessive secretion of inflammatory factors, increased mass, and amplified contractile responses of ASM, and is a critical etiological factor implicated in the dysregulation of ASM function. The molecular pathways through which oxidative stress exerts its effects on ASM in asthma are multifaceted, with the Nrf2/HO-1, MAPK, and PI3K/Akt pathways being particularly noteworthy. These characteristic pathways play a potential role by connecting with different upstream and downstream signaling molecules and are involved in the amplification of ASM inflammatory responses, increased mass, and AHR. This review provides a comprehensive synthesis of the phenotypic expression of ASM dysfunction in asthma, the interplay between oxidants and antioxidants, and the evidence base and molecular underpinnings linking oxidative stress to ASM dysfunction. Given the profound implications of ASM dysfunction on the airflow limitation in asthma and the seminal role of oxidative stress in this process, a deeper exploration of these mechanisms is essential for unraveling the pathogenesis of asthma and may offer novel perspectives for its prophylaxis and management.

Safranal restores RUNX3-mediated immunoregulation by inhibiting the NLRP3 inflammasome in allergic asthma

Safranal is an active ingredient with pharmacological anti-inflammatory effects derived from Crocus sativus essential oil. To explore the comprehensive effects of Safranal on airway inflammation, airway hyperreactivity, and remodeling and its potential mechanisms through the allergic asthma model, an in vitro model of ASMC cells stimulated by TNF-α was established. The cells were transfected with si-RUNX3 and RUNX3 overexpression plasmids, and DEX was used as a positive control. The expression of RUNX3 was detected by western blot and immunofluorescence. The levels of inflammatory factors were measured by ELISA, while flow cytometry detected the anti-apoptotic effects and ROS production. Subsequently, OVA-sensitized WT mice and RUNX3-KO mice were administered with DEX and Safranal for 2 weeks to establish a mouse model of allergic asthma, and changes in airway hyperresponsiveness, inflammatory manifestations, and airway remodeling were detected. The mechanism of Safranal was verified by detecting the expression of RUNX3, inflammation, and fibrosis-related proteins in the lung tissues. By modulating the NLRP3/Caspase-1 pathway, Safranal significantly alleviated the negative effects caused by RUNX3 suppression in vivo and in vitro. We propose that Safranal is a potential active compound for the treatment of asthma, and its clinical application value in allergic asthma should be further explored.

Quercetin improves airway remodeling in COPD rats by suppressing phenotypic switch of ASMCs via inhibiting the Wnt5a/β-catenin pathway

BACKGROUND AND PURPOSE

Airway remodeling in chronic obstructive pulmonary disease (COPD) is a contributor to airflow limitation, promotes disease progression, and affects disease outcome and prognosis. Quercetin has been identified as a potential therapeutic agent for COPD. Currently, there is insufficient research providing direct evidence to support this hypothesis. The present study investigates the therapeutic effects and the underlying mechanisms of quercetin in the alleviation of airway remodeling in rat models of COPD.

EXPERIMENTAL STEPS

This study used a network pharmacology approach to predict, for the first time, the potential molecular targets of quercetin in COPD. The effects of quercetin on phenotypic switching and mitochondrial function of ASMCs were assessed in vitro using CCK-8, EdU staining, migration assays, western blotting, and JC-1 staining. Additionally, the interaction between Wnt5a and quercetin was analyzed via molecular docking, and findings were experimentally confirmed using the cellular thermal shift assay (CETSA). Quercetin's influence on airway remodeling in COPD was examined in vivo through pulmonary function evaluation, H&E staining, and Modified Sirius Red staining. Molecular alterations associated with phenotypic switching, oxidative stress, autophagy and Wnt5a/β-Catenin pathway were examined by Western blotting, immunofluorescence, immunohistochemistry, DHE staining and ELISA.

KEY RESULTS

The results showed that quercetin has a beneficial therapeutic effect on COPD. Its ability to mitigate airway remodeling is linked to modulating autophagy levels, reducing oxidative stress, alleviating mitochondrial damage, and influencing the phenotypic switch in ASMCs. By increasing oxidative stress tolerance, quercetin reduces mitochondrial damage and regulates the phenotypic switch in ASMCs. Furthermore, quercetin suppresses autophagy hyperactivation, which subsequently lowers oxidative stress levels in ASMCs. Notably, quercetin modulates autophagy through the regulation of the Wnt5a/β-catenin signaling pathway.

CONCLUSION AND IMPLICATIONS

In conclusion, quercetin demonstrates potential therapeutic effects in COPD by suppressing the Wnt5a/β-cateninsignaling pathway, autophagy as well as oxidative stress, and thereby alleviating mitochondrial damage and the phenotypic switch in ASMCs. These findings may have clinical applications and offer new insights for the development of COPD treatments.

Research trends on airway remodeling: A bibliometrics analysis

Background

Airway remodeling is an essential pathological basis of respiratory diseases such as asthma and COPD, which is significantly related to pulmonary function and clinical symptoms. And pulmonary disease can be improved by regulating airway remodeling. This study aimed to establish a knowledge map of airway remodeling to clarify current research hotspots and future research trends.

Methods

A comprehensive search was performed to analyze all relevant articles on airway remodeling using the Web of Science Core Collection Database from January 01, 2004 to June 03, 2023.2 reviewers screened the retrieved literature. Besides, the CiteSpace (6.2. R3) and VOSviewer (1.6.19) were utilized to visualize the research focus and trend regarding the effect of airway remodeling.

Results

A total of 4077 articles about airway remodeling were retrieved. The United States is the country with the most published literature, underscoring the country's role in airway remodeling. In recent years, China has been the country with the fastest growth in the number of published literature, suggesting that China will play a more critical role in airway remodeling in the future. From the perspective of co-operation among countries, European co-operation was closer than Asian co-operation. The co-citation analysis showed that 98,313 citations were recorded in 3594 articles, and 25 clusters could be realized. In recent years, Burst detection shows that oxidative stress and epithelial-mesenchymal transition are hot words.

Conclusions

Based on the bibliometric analysis of airway remodeling studies in the past 20 years, a multi-level knowledge structure map was drawn, it mainly includes countries, institutions, research fields, authors, journals, keywords and so on. The research directions represented by obstructive airway disease, PDGF-BB treatment of airway smooth muscle, allergen-induced airway remodeling, extracellular matrix, and non-coding RNA are the research hotspots in the field of airway remodeling. While the risk factors for airway remodeling, the application of new noninvasively assessing tools, biomarkers as well as The molecular mechanism represented by EMT and autophagy had been frontiers in recent years.

Macrophage migration inhibitory factor exacerbates asthmatic airway remodeling via dynamin-related protein 1-mediated autophagy activation

BACKGROUND

Macrophage migration inhibitory factor (MIF) and GTPase dynamin-related protein 1 (Drp1)-dependent aberrant mitochondrial fission are closely linked to the pathogenesis of asthma. However, it is unclear whether Drp1-mediated mitochondrial fission and its downstream targets mediate MIF-induced proliferation of airway smooth muscle cells (ASMCs) in vitro and airway remodeling in chronic asthma models. The present study aims to clarify these issues.

METHODS

In this study, primary cultured ASMCs and ovalbumin (OVA)-induced asthmatic rats were applied. Cell proliferation was detected by CCK-8 and EdU assays. Western blotting was used to detect extracellular signal-regulated kinase (ERK) 1/2, Drp1, autophagy-related markers and E-cadherin protein phosphorylation and expression. Inflammatory cytokines production, airway reactivity test, histological staining and immunohistochemical staining were conducted to evaluate the development of asthma. Transmission electron microscopy was used to observe the mitochondrial ultrastructure.

RESULTS

In primary cultured ASMCs, MIF increased the phosphorylation level of Drp1 at the Ser616 site through activation of the ERK1/2 signaling pathway, which further activated autophagy and reduced E-cadherin expression, ultimately leading to ASMCs proliferation. In OVA-induced asthmatic rats, MIF inhibitor 4-iodo-6-phenylpyrimidine (4-IPP) treatment, suppression of mitochondrial fission by Mdivi-1 or inhibiting autophagy with chloroquine phosphate (CQ) all attenuated the development of airway remodeling.

CONCLUSIONS

The present study provides novel insights that MIF promotes airway remodeling in asthma by activating autophagy and degradation of E-cadherin via ERK/Drp1 signaling pathway, suggesting that targeting MIF/ERK/Drp1 might have potential therapeutic value for the prevention and treatment of asthma.