Asthma: New Integrative Treatment Strategies for the Next Decades

Yanghe Pingchuan granules induce ferroptosis in airway smooth muscle cells to improve bronchial asthma via the METTL3/P53/SLC7A11 signaling pathway

BACKGROUND

Recent studies have found that ferroptosis is strongly associated with the development of bronchial asthma (BA). However, the mechanism underlying the role of ferroptosis in asthma remains unclear. Yanghe Pingchuan granules (YPG) have significant curative effect in the clinical treatment of BA. In our previous study, we found that YPG inhibit pyroptosis in the airway smooth muscle cells (ASMCs) of and reducing airway inflammation. Whether ferroptosis participated in the YPG treated BA activity is an interesting project.

PURPOSE

The aim of this study was to investigate the protective effects and the related mechanisms of YPG against BA.

METHODS

We used ultra high-performance liquid chromatograph (UPLC) to analyze the composition of YPG. Ovalbumin (OVA)-induced BA models were developed in vivo. YPG was administered to rats by gavage and ASMCs were isolated and cultured using α-SMA and CCK8 was used to assess cell viability. Gene editing, m6A RNA immunoprecipitation (MeRIP), western blotting, RT-qPCR, and transmission electron microscopy (TEM) was used to assess ferroptosis protein and mRNA expression in ASMCs. Further, the mechanism of YPG-induced regulation of ferroptosis in ASMCs via the METTL3/P53/SLC7A11 signaling axis was interrogated. BA rats were used to verify the therapeutic effects and mechanism of YPG. Moreover, hematoxylin and eosin staining was used to evaluate pathological changes using animal samples, while immunofluorescence, western blotting, RT-qPCR, and TEM were used to verify the mechanism by which YPG improved BA through the METTL3/P53/SLC7A11 signaling axis.

RESULTS

Qualitative analysis revealed seven major components in YPG. Our in vivo and in vitro data confirm that YPG significantly induced ferroptosis in ASMCs. YPG treatment effectively increased the expression of Fe2+, P53, and PTGS2, while decreasing SLC7A11, GPX4, and FTH1 expression. Moreover, TEM data revealed that YPG-induced mitochondrial membrane rupture and ridge disappearance. Additionally, YPG significantly increased METTL3 expression levels and upregulated the levels of P53 m6A, thus promoting its degradation. Notably, overexpression of METTL3 and P53 induces ferroptosis of ASMCs BA rats.

CONCLUSION

We show that YPG may induce ferroptosis of ASMCs in BA rats by activating the METTL3/P53/SLC7A11 signaling pathway, thus alleviating disease symptoms.

The interplay of plant-based antioxidants, inflammation, and clinical outcomes in asthma: A systematic review

BACKGROUND

Asthma is a chronic inflammatory disease and a leading cause of disability, posing a huge economic and social burden. Plant-based antioxidants have the potential to block proinflammatory pathways and protect against oxidative damage, which could improve asthma management.

OBJECTIVE

This review examines the role of plant-based antioxidants as adjuvant therapy on inflammatory markers and clinical outcomes of adults with asthma.

METHODS

Digital databases, including Scopus, MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Airway Group's Specialized Register of Trials, were searched. Two independent authors performed initial and full-text screening of identified papers. The criteria for study inclusion and exclusion were predefined. Two authors independently performed data extraction and risk of bias as per the PRISMA checklist.

RESULTS

After full-text screening, nine randomized controlled trials were included in the final review. Seven of the included studies highlighted the efficacy of plant-based antioxidants in modulating the inflammatory cytokines in asthmatics. The benefits of antioxidants were also observed for improving oxidative status, lung functioning, and airway inflammatory markers. Furthermore, the overall quality of asthmatic patients' lives was improved with fewer exacerbations such as night coughs and wheezing. Despite having some limitations, the overall risk of bias was low in this review.

CONCLUSION

The review indicated that plant-based antioxidants could have adjuvant beneficial effects in the management of asthma inflammatory markers, which may help improve asthma-related clinical outcomes. However, due to the small number of study subjects, further research is required on the effect of plant-based antioxidants on asthma-inflammatory markers and clinical outcomes.

A survey on awareness of the disease and pulmonary rehabilitation in bronchial asthma patients in the United Arab Emirates

BACKGROUND

Asthma, a prevalent and severe chronic respiratory condition, can be significantly managed and controlled through informed awareness about the disease and pulmonary rehabilitation strategies, thereby enhancing patients' health-related quality of life.

OBJECTIVE

To determine the knowledge and awareness of Bronchial asthma and pulmonary rehabilitation among asthma-diagnosed patients in the United Arab Emirates.

METHODS

Utilizing a cross-sectional study design, 237 asthma patients, aged 18 and above, were recruited from the Royal NMC Hospital, Sharjah. A comprehensive questionnaire was administered, focusing on two critical domains: understanding of the disease and knowledge about pulmonary rehabilitation. Data analysis was performed using the Statistical Package for Social Sciences (SPSS) software, version 26.

RESULTS

The majority of participants (31.6%) reported the onset of asthma before reaching two years of age. Bronchodilators emerged as the most used medication, utilized by 31.6% of the respondents. Weather conditions (34.6%) were identified as the most prevalent risk factor. Chi-square tests revealed no significant correlations between gender and knowledge about asthma (p = 0.278) or pulmonary rehabilitation awareness (p = 0.929). A negative correlation was found between age and knowledge about asthma (p<0.001), but not with pulmonary rehabilitation awareness (p = 0.731). Education demonstrated no significant association with either knowledge about asthma (p = 0.974) or awareness of pulmonary rehabilitation (p = 0.676).

CONCLUSION

The study implies that most people have a basic understanding of asthma. However, there are still significant gaps in their knowledge. For instance, many aren't sure how asthma is influenced by exercise or which parts of the body are affected. Also, understanding about therapies such as lung rehabilitation, and the contributions physical therapists can make in addressing lung problems, is only average. Interestingly, these knowledge gaps are not related to a person's age or their educational background.

Serum autophagy protein 5 is positively related to T helper 2/T helper 1 ratio, inflammation, and exacerbation in adult asthma patients

BACKGROUND

Autophagy protein 5 (ATG5) regulates airway epithelial cell autophagy, immune response, and inflammation, which is involved in asthma progression. This study aimed to evaluate ATG5 levels and its clinical roles in adult asthma patients.

METHODS

Totally, 200 adult asthma patients and 100 healthy controls (HCs) were enrolled in this case-control study. Subsequently, serum ATG5 was measured by enzyme-linked immunosorbent assay.

RESULTS

ATG5 was increased in asthma patients compared with HCs [median (interquartile range): 44.2 (31.7-77.8) vs. 23.2 (16.7-39.2) ng/mL] (P < 0.001). In asthma patients, ATG5 was positively related to male gender (P = 0.022), a family history of asthma (P = 0.035), eosinophil count (P < 0.001), and immune globulin E (P < 0.001), while it was negatively correlated with forced expiratory volume in 1 s (FEV1)/forced vital capacity (P < 0.001) and FEV1 (Predicted) (P < 0.001). Meanwhile, ATG5 was inversely associated with T helper (Th) 1 cells (P = 0.008), while it was positively linked with Th2 cells (P < 0.001), Th2/Th1 ratio (P < 0.001), interleukin (IL)-4 (P = 0.002), and IL-4/interferon-γ ratio (P = 0.015). Additionally, ATG5 was positively correlated with tumor necrosis factor-α (P < 0.001), IL-1β (P = 0.001), IL-6 (P = 0.003), and IL-17 (P = 0.029). Notably, ATG5 was elevated in asthma patients at exacerbation compared to those at remission [median (interquartile range): 53.6 (37.6-90.0) vs. 35.6 (28.2-51.5) ng/mL] (P < 0.001). It was also noteworthy that ATG5 was positively linked with exacerbation severity in asthma patients (P = 0.005).

CONCLUSION

Serum ATG5 is related to increased Th2/Th1 ratio, inflammation, exacerbation risk and severity in adult asthma patients, which serves as a candidate marker for the management of asthma. However, further validation is still needed.

S14G-Humanin ameliorates ovalbumin-induced airway inflammation in asthma mediated by inhibition of toll-like receptor 4 (TLR4) expression and the nuclear factor κ-B (NF-κB)/early growth response protein-1 (Egr-1) pathway

Asthma is a chronic inflammatory disease with a high morbidity rate in children and significantly impacts their healthy growth. It is reported that Th2 cell-mediated airway inflammation and activated oxidative stress are involved in the pathogenesis of asthma. S14G-humanin (HNG) is a derivative of Humanin with higher activity. The present study proposes to explore the potential treating property of HNG on asthma. An asthma model was constructed in mice using ovalbumin (OVA), the mice were treated with 2.5 mg/kg and 5 mg/kg HNG for 16 days. Dramatically increased lung weight index, elevated number of monocytes, eosinophils, and neutrophils, promoted production of Th2 cytokines including interleukin-4 (IL-4), interleukin-5 (IL-5), and interleukin-13 (IL-13), and severe histological pathology were observed in OVA-challenged mice, all of which were extremely alleviated by 2.5 mg/kg and 5 mg/kg HNG. Furthermore, the increased malondialdehyde (MDA) level and declined superoxide dismutase (SOD) activity in OVA-challenged mice were abolished by 2.5 mg/kg and 5 mg/kg HNG. Lastly, the upregulated TLR4, p-NF-κB p65, and early growth response 1 (Egr-1) in lung tissues of OVA-challenged mice were pronouncedly downregulated by 2.5 mg/kg and 5 mg/kg HNG. Collectively, our data suggested that HNG ameliorated airway inflammation in asthma partially due to NF-κB and Egr-1-mediated responses.

Programmed Cell Death in Asthma: Apoptosis, Autophagy, Pyroptosis, Ferroptosis, and Necroptosis

Bronchial asthma is a complex heterogeneous airway disease, which has emerged as a global health issue. A comprehensive understanding of the different molecular mechanisms of bronchial asthma may be an efficient means to improve its clinical efficacy in the future. Increasing research evidence indicates that some types of programmed cell death (PCD), including apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis, contributed to asthma pathogenesis, and may become new targets for future asthma treatment. This review briefly discusses the molecular mechanism and signaling pathway of these forms of PCD focuses on summarizing their roles in the pathogenesis and treatment strategies of asthma and offers some efficient means to improve clinical efficacy of therapeutics for asthma in the near future.

BRD7 restrains TNF-α-induced proliferation and migration of airway smooth muscle cells by inhibiting notch signaling

Objective: Bromodomain-containing protein 7 (BRD7) is a key component of the switch/sucrose non-fermentable complex that participates in chromatin remodeling and transcriptional regulation. Although the emerging role of BRD7 in the pathophysiology of various diseases has been observed, its role in asthma remains unknown. Here, we assessed the function of BRD7 as a mediator of airway remodeling in asthma using an in vitro model. Methods: Airway smooth muscle cells (ASMCs) were challenged with tumor necrosis factor-α (TNF-α) to establish an in vitro airway remodeling model. Protein levels were examined using western blotting. Cell proliferation was measured using the cell counting kit-8 and 5-ethynyl-2'-deoxyuridine assays. Cell migration was assessed using a transwell migration assay. Results: Exposure to TNF-α dramatically decreased BRD7 levels in ASMCs. BRD7 remarkably decreased TNF-α-induced proliferation and migration of ASMCs. In contrast, ASMCs with BRD7 deficiency were more sensitive to TNF-α-induced pro-proliferative and pro-migratory effects. Mechanistically, BRD7 could repress the expression of Notch1 and block the Notch pathway in TNF-α-challenged cells. Notably, reactivation of Notch signaling substantially reversed the BRD7 overexpression-mediated effects, whereas restraining Notch signaling abolished BRD7-depletion-mediated effects on TNF-α-challenged cells. Conclusions: BRD7 inhibits the proliferation and migration of ASMCs elicited by TNF-α by downregulating the Notch pathway. This study indicates that BRD7 may exert a suppressive effect on airway remodeling during asthma.

Yanghe Decoction Effectively Alleviates Lung Injury and Immune Disorder in Asthmatic Mice Induced by Ovalbumin

Objective. To probe into the ameliorative effect of Yanghe Decoction on pulmonary injury and immunologic derangement in asthmatic mice. Methods. C57BL/6 mice were randomized into control (Con), Model, and Yanghe Decoction (YHF) groups, with 12 in each. The asthma model of adult female mice was induced by ovalbumin in the Model group, and the YHF group was treated by Yanghe Decoction on the basis of asthma modeling. The Con group received the same amount of normal saline. Inspiratory resistance (Ri), expiratory resistance (Re), lung compliance (CL), and maximal voluntary ventilation (MVV) were measured after modeling. Lung tissue was collected for the measurement of interleukin (IL)-4, IL-5, IL-6, IL-10, IL-13, and tumor necrosis factor-α (TNF-α) by ELISA kits. Combined with HE staining and PAS staining, the pathological alterations of the lung in each group were observed, and CD4+, Th2, and Th1 contents were determined by flow cytometry (FCM). Results. The pulmonary function (PF) test revealed notably reduced Ri and Re as well as enhanced CL and MVV in asthmatic mice after the application of Yanghe Decoction. Yanghe Decoction dramatically ameliorated the pathological changes of lung tissue in asthmatic mice, as demonstrated by the staining results. ELISA results showed that Yanghe Decoction validly reduces lung tissue IL-4, IL-5, IL-6, IL-13, TNF-α and upregulates IL-10 in asthmatic mice. FCM indicated that Yanghe Decoction obviously reduced the number of Th1 and Th2 cells in asthmatic mice, although it caused the decrease of CD4+ cells, but the difference was not statistically significant. Conclusions. Yanghe Decoction can effectively ameliorate the inflammatory reaction, immune cell disorder, and PF injury in ovalbumin-induced asthmatic mice.

Mediterranean-Type Diets as a Protective Factor for Asthma and Atopy

We are currently riding the second wave of the allergy epidemic, which is ongoing in affluent societies, but now also affecting developing countries. This increase in the prevalence of atopy/asthma in the Western world has coincided with a rapid improvement in living conditions and radical changes in lifestyle, suggesting that this upward trend in allergic manifestations may be associated with cultural and environmental factors. Diet is a prominent environmental exposure that has undergone major changes, with a substantial increase in the consumption of processed foods, all across the globe. On this basis, the potential effects of dietary habits on atopy and asthma have been researched rigorously, but even with a considerable body of evidence, clear associations are far from established. Many factors converge to obscure the potential relationship, including methodological, pathophysiological and cultural differences. To date, the most commonly researched, and highly promising, candidate for exerting a protective effect is the so-called Mediterranean diet (MedDi). This dietary pattern has been the subject of investigation since the mid twentieth century, and the evidence regarding its beneficial health effects is overwhelming, although data on a correlation between MedDi and the incidence and severity of asthma and atopy are inconclusive. As the prevalence of asthma appears to be lower in some Mediterranean populations, it can be speculated that the MedDi dietary pattern could indeed have a place in a preventive strategy for asthma/atopy. This is a review of the current evidence of the associations between the constituents of the MedDi and asthma/atopy, with emphasis on the pathophysiological links between MedDi and disease outcomes and the research pitfalls and methodological caveats which may hinder identification of causality. MedDi, as a dietary pattern, rather than short-term supplementation or excessive focus on single nutrient effects, may be a rational option for preventive intervention against atopy and asthma.

Serum Concentration of the Phytohormone Abscisic Acid Is Associated With Immune-Regulatory Mediators and Is a Potential Biomarker of Disease Severity in Chronic Obstructive Pulmonary Disease

COPD and asthma are two distinct but sometimes overlapping diseases exhibiting varying degrees and types of inflammation on different stages of the disease. Although several biomarkers are defined to estimate the inflammatory endotype and stages in these diseases, there is still a need for new markers and potential therapeutic targets. We investigated the levels of a phytohormone, abscisic acid (ABA) and its receptor, LANCL2, in COPD patients and asthmatics. In addition, PPAR-γ that is activated by ABA in a ligand-binding domain-independent manner was also included in the study. In this study, we correlated ABA with COPD-propagating factors to define the possible role of ABA, in terms of immune regulation, inflammation, and disease stages. We collected blood from 101 COPD patients, 52 asthmatics, and 57 controls. Bronchoscopy was performed on five COPD patients and 29 controls. We employed (i) liquid chromatography–tandem mass spectrometry and HPLC to determine the ABA and indoleamine 2,3-dioxygenase levels, respectively; (ii) real-time PCR to quantify the gene expression of LANCL2 and PPAR-γ; (iii) Flow cytometry to quantify adipocytokines; and (iv) immunoturbidimetry and ELISA to measure CRP and cytokines, respectively. Finally, a multinomial regression model was used to predict the probability of using ABA as a biomarker. Blood ABA levels were significantly reduced in COPD patients and asthmatics compared to age- and gender-matched normal controls. However, PPAR-γ was elevated in COPD patients. Intriguingly, ABA was positively correlated with immune-regulatory factors and was negatively correlated with inflammatory markers, in COPD. Of note, ABA was increased in advanced COPD stages. We thereby conclude that ABA might be involved in regulation of COPD pathogenesis and might be regarded as a potential biomarker for COPD stages.

Ozone-Induced Oxidative Stress, Neutrophilic Airway Inflammation, and Glucocorticoid Resistance in Asthma

Despite recent advances in using biologicals that target Th2 pathways, glucocorticoids form the mainstay of asthma treatment. Asthma morbidity and mortality remain high due to the wide variability of treatment responsiveness and complex clinical phenotypes driven by distinct underlying mechanisms. Emerging evidence suggests that inhalation of the toxic air pollutant, ozone, worsens asthma by impairing glucocorticoid responsiveness. This review discusses the role of oxidative stress in glucocorticoid resistance in asthma. The underlying mechanisms point to a central role of oxidative stress pathways. The primary data source for this review consisted of peer-reviewed publications on the impact of ozone on airway inflammation and glucocorticoid responsiveness indexed in PubMed. Our main search strategy focused on cross-referencing "asthma and glucocorticoid resistance" against "ozone, oxidative stress, alarmins, innate lymphoid, NK and γδ T cells, dendritic cells and alveolar type II epithelial cells, glucocorticoid receptor and transcription factors". Recent work was placed in the context from articles in the last 10 years and older seminal research papers and comprehensive reviews. We excluded papers that did not focus on respiratory injury in the setting of oxidative stress. The pathways discussed here have however wide clinical implications to pathologies associated with inflammation and oxidative stress and in which glucocorticoid treatment is essential.