Targeting cell signaling in allergic asthma

The role of mesenchymal stem cell‑derived exosomes in asthma (Review)

Asthma is a chronic respiratory disorder characterized by persistent inflammation, airway hyper‑responsiveness and remodeling, leading to notable morbidity and decreased quality of life for patients. Mesenchymal stem cells (MSCs) have potential in regenerative medicine due to their potent immunomodulatory properties and anti‑inflammatory effects. The therapeutic benefits of MSCs are largely mediated by secreted exosomes that facilitate intercellular communication by transferring bioactive molecules, including proteins, lipids and microRNAs. The present review explores the therapeutic potential of MSC‑derived exosomes in asthma, highlighting their ability to modulate key pathological mechanisms underlying the disease.

Enhancing the nutraceutical and nutritional features of wheat germ to reduce atopic asthma symptoms in children

BACKGROUND

The rise in childhood asthma has increased interest in nutraceutical treatment options such as specific nutritional supplements, as medical treatments may not always produce the desired results. Despite treatment, between 30 and 50% of children with asthma do not attain adequate control.

OBJECTIVES

For the first time, the effects of adding fermented wheat germ to the daily diet of children with atopic asthma on respiratory function-related disease symptoms, serum IgE, and eosinophil levels were studied.

METHODS

The study comprised 52 patients (control group n = 26, experimental group n = 26) aged 12-18 years with a clear diagnosis of atopic asthma. The experimental group consumed 100 g of fermented wheat bread with 5% wheat germ every day for three months, while the control group consumed standard bread. The groups were assessed at baseline and at the end of each month with spirometry (FVC, FEV1, PEF), serum eosinophil and IgE measurements, and the application of the Asthma Control Test (ACT) scale.

RESULTS

There was no significant difference between the control and experimental groups in terms of any measurement. The experimental group had significant increases in PEF (p < 0.05), FVC, and IgE levels (p < 0.001) compared to monthly measurements. Both groups showed statistically significant improvements in ACT and FEV1 (p < 0.001). Nonetheless, the control and experimental groups showed no significant difference in time-dependent eosinophil levels (p > 0.05).

CONCLUSIONS

Although the inclusion of fermented wheat germ to asthmatic children's diets has been shown to improve PEF and IgE levels, these findings require further investigation.

Atopic Dermatitis: The Relationship Between Immune Mediators and Skin Lipid Barrier

Atopic dermatitis (AD) is a chronic inflammatory skin disease that is prevalent worldwide with complex etiology. Skin barrier defects and abnormal immune activation are crucial in the occurrence and development of AD. In the classic model of the skin barrier, lipids are essential for the formation and maintenance of this barrier as a "mortar" component. However, abnormally activated immune responses promote the lipid barrier deficiency through the secretion of various types of immune mediators directly or indirectly. In this review, we first introduce the skin lipid barrier (SLB) under both normal and abnormal conditions, highlighting the contributions of lipids derived from keratinocytes and sebaceous glands (SGs). Subsequently, the relationships between the immune mediators of Th1, Th2, Th17, Th22, and other types (adipokines, prostaglandins, leukotrienes) and SLB are elaborated in turn. Finally, the therapies for restoring SLB to treat AD are summarized, with a focus on the restoration effect of dupilumab on SLB. We hope that this review will offer a comprehensive perspective for understanding the pathogenesis of lipid metabolism disorders and SLB deficiency caused by immune mediators in AD. It also aims to provide guidance for further research on targeting inflammatory mediators to restore SLB.

Engineered Spirulina platensis for treating rheumatoid arthritis and restoring bone homeostasis

Rheumatoid arthritis (RA) is characterized by massive intra-articular infiltration of pro-inflammatory macrophages, leading to articular immune dysfunction, severe synovitis, and ultimately joint erosion. Comprehensive remodeling of articular immune homeostasis and bone homeostasis is essential for alleviating RA. Here we report on Spirulina platensis (SP), a natural microorganism commercially farmed worldwide as a food, as an efficient regulator of both synovial inflammation and osteoclast differentiation in male RA mouse models. SP reduces excessive reactive oxygen species and downregulates pro-inflammatory cytokines in synovial macrophages. Moreover, SP reprograms pro-inflammatory M1-like macrophages to anti-inflammatory M2-like phenotype, suppressing synovitis and remodeling redox balance. Notably, SP inhibits osteoclast activation effectively and blocks the progression of bone erosion. SP is then engineered with macrophage membranes (SP@M) to enable immune evasion and RA-targeting in vivo. SP@M increases LC3-mediated autophagy as well as strengthens ubiquitin-mediated proteasomal degradation toward KEAP1, which promotes the expression and nuclear translocation of NRF2. The NRF2 further activates antioxidant enzymes to terminate macrophages-initiated pathological cascades and reestablish intra-articular immune homeostasis, conferring a bone recovery and chondroprotective effect in collagen-induced arthritis mouse models. This work shows the therapeutic activity of FDA-approved functional food of SP in suppressing synovial inflammation and osteoclast differentiation, offering an off-the-shelf strategy for RA treatment.

CFTR negatively reprograms Th2 cell responses, and CFTR potentiation restrains allergic airway inflammation

Type 2 inflammatory diseases, including asthma, sinusitis, and allergic bronchopulmonary aspergillosis, are common in cystic fibrosis (CF). CD4+ Th2 cells promote these diseases through secretion of IL-4, IL-5, and IL-13. Whether the CF transmembrane conductance regulator (CFTR), the mutated protein in CF, has a direct effect on Th2 development is unknown. Using murine models of CFTR deficiency and human CD4+ T cells, we show that CD4+ T cells expressed Cftr transcript and CFTR protein following activation. Loss of T cell CFTR expression increased Th2 cytokine production compared with control cells. Mice with CFTR-deficient T cells developed increased allergic airway disease to Alternaria alternata extract compared with control mice. Culture of CFTR-deficient Th2 cells demonstrated increased IL-4Rα expression and increased sensitivity to IL-4 with greater induction of GATA3 and IL-13 compared with control Th2 cell cultures. The CFTR potentiator ivacaftor reduced allergic inflammation and type 2 cytokine secretion in bronchoalveolar lavage of humanized CFTR mice following Alternaria alternata extract challenge and decreased Th2 development in human T cell culture. These data support a direct role of CFTR in regulating T cell sensitivity to IL-4 and demonstrate a potential CFTR-specific therapeutic strategy for Th2 cell-mediated allergic disease.

Neurons as Immunomodulators: From Rapid Neural Activity to Prolonged Regulation of Cytokines and Microglia

Regulation of the brain's neuroimmune system is central to development, normal function, and disease. Neuronal communication to microglia, the primary immune cells of the brain, is well known to involve purinergic signaling mediated via ATP secretion and the cytokine fractalkine. Recent evidence shows that neurons release multiple cytokines beyond fractalkine, yet these are less studied and poorly understood. In contrast to ATP, cytokines are a class of signaling molecule that are much larger, with longer signaling and farther diffusion. We posit that neuron-expressed cytokines are an essential mechanism of neuron-microglia communication that arises as part of both normal learning and memory and in response to tissue pathology. Thus, neurons are underappreciated immunomodulatory cells that express diverse immunomodulatory signals. While neuronally sourced cytokines have been understudied, new technical advances make this a timely topic. The goal of this review is to define what is known about the cytokines expressed from neurons, how they are regulated, and the effects of these cytokines on microglia. We delineate key knowledge gaps and needs for new tools to define and analyze neuronal roles in immunomodulation. Given that cytokines are central regulators of microglial function, a broad new body of work is required to illuminate functional links between these neuronally expressed cytokines and sustained and transient microglial function.

TRIM7 knockdown protects against LPS-induced autophagy, ferroptosis, and inflammatory responses in human bronchial epithelial cells

Asthma is one of the most common respiratory diseases in pediatric department. Several asthma-associated events including inflammatory responses, autophagy, and ferroptosis have been identified as typical pathological processes. TRIM7 is a member of TRIM proteins family associated with several types of diseases. Nevertheless, its role in asthma is still elusive. The current research showed that TRIM7 was involved in the pathogenesis of asthma mainly by regulating the Akt signaling pathway. In detail, we found that TRIM7 was highly expressed in patients with asthma and in an in vitro model of asthma. The following analysis indicated that TRIM7 knockdown attenuated the expression and secretion of inflammatory cytokines including TNF-α, IL-1β and IL-6 in lipopolysaccharide (LPS)-exposed human bronchial epithelial cells (HBECs). Meanwhile, knockdown of TRIM7 exerted inhibitory effects on LPS-induced autophagy and ferroptosis. Further mechanistic studies showed that TRIM7 knockdown inhibited LPS-induced activation of Akt pathway, while overexpression of Akt attenuated the inhibitory effects of TRIM7 knockdown on LPS-exposed HBECs. Collectively, we reported here that TRIM7 knockdown inhibited LPS-induced autophagy, ferroptosis, and inflammatory cytokine secretion in HBECs via regulating the Akt pathway, providing a new insight into the strategies for improving asthma treatments.

Deciphering the role of cytokines in aging: Biomarker potential and effective targeting

Aging is often characterized by chronic inflammation, immune system dysregulation, and cellular senescence with chronically elevated levels of pro-inflammatory cytokines. These small glycoproteins are mainly secreted by immune cells, mediating intercellular communication and immune system modulation through inflammatory signaling. Their pro- and anti-inflammatory effects make them a noteworthy research topic as well as a promising ally in combating inflammation and the aging process. Cytokines exert a synergistic role in aging and disease and may prove useful biomarkers of tissue-specific dysregulation, disease diagnosis and monitoring, presenting potential therapeutic options as anti-inflammatory and senolytic medications. In this review, we address the cellular and molecular mechanisms implicating cytokines in the aging process and related diseases, highlighting their biomarker potential. We focus on the current therapeutic strategies, including specific pharmaceutical agents, supplements, a balanced diet, and healthy habits such as exercise, stress management, and caloric restriction.

The synergistic effects of PM2.5 and high-fat diet on Th1/Th2 balance in model mice with asthma

Background

Particulate matter, ambient particulate matter with an aerodynamic equivalent diameter ≤2.5 µm (PM2.5) is closely associated with asthma, and a high-fat diet is also a risk factor for the condition. In many cities in China, exposure to PM2.5 and consumption of a high-fat diet coexist. The Th1/Th2 balance is the immunological foundation for the onset and progression of asthma, and it is more accurate to describe asthma symptoms in terms of changes in this balance. Therefore, the aim of this study was to investigate the effects of PM2.5 and high-fat diet the combined effects on Th1/Th2 balance in asthma immune.

Methods

Given this background, our study examined the effects of PM2.5 and high-fat diets on the Th1/Th2 balance and proposed potential molecular mechanisms for asthma development induced by these factors. In this study, male BALB/c mice and ovalbumin (OVA)-sensitized asthma mice subjected to either a normal or high-fat diet were exposed to PM2.5 or filtered air for one month. We evaluated the effects of PM2.5 and high-fat diets on asthma using histopathology, enzyme-linked immunosorbent assays, transcriptome sequencing, and quantitative polymerase chain reaction (PCR).

Results

We found that PM2.5 exposure increased the secretion of Th2-related inflammatory mediators, while a high-fat diet increased the secretion of Th1-related inflammatory mediators. However, the combined effects still predominantly favored a Th2 skew. PM2.5 exposure shifted the Th1/Th2 balance toward Th2, whereas a high-fat diet shifted it toward Th1. The combination of PM2.5 exposure and a high-fat diet resulted in a less pronounced Th2 polarization compared to PM2.5 exposure alone.

Conclusions

PM2.5 exposure and short-term high-fat diet both exacerbate asthma but there is an opposite direction of modulation of the Th1/Th2 balance.

Zhichuanling injection improves bronchial asthma by attenuation airway inflammation and epithelia-mesenchymal transition

ETHNOPHARMACOLOGICAL RELEVANCE

Zhichuanling (ZCL) Injection, is a compound formulation containing extracts of mahuang (Herba Ephedrae, dried stem or aerial part of Ephedra sinica Stapf), bitter almond (Semen Armeniacae Amarum, seeds of Prunus armeniaca var. sibirica (L.) K. Koch), yangjinhua (flower of Datura metel L.) and Fructus Forsythiae (fruits of Forsythia suspensa (Thunb.) Vahl). Intramuscular injection of ZCL has been used in the clinical practice to control asthma. The aerosol inhalation of ZCL has been shown to be effective on allergic bronchial asthma. However, the underlying mechanisms remain established.

AIM OF THE STUDY

To investigate the underling mechanism by which ZCL inhibits the pathogenesis of bronchial asthma.

METHODS

The guinea pig tracheal rings and human bronchial epithelial (16HBE) cells were used to assess ZCL's impact on acetylcholine (Ach) induced tracheal contraction, tumor necrosis factor α (TNF-α) induced bronchial inflammation, and transforming growth factor-β1 (TGF-β1) induced airway remodeling. Cell viability and gene expression were assessed using MTT assays, qPCR. RNA-seq (gene expression analysis) was employed to explore the novel mechanisms of ZCL in OVA-induced bronchial asthma.

RESULTS

In this study, we found that ZCL reduces Ach-induced contraction of isolated guinea pig trachea, suppress TNF-α-induced interleukin (IL)-1β, IL-6, and IL-8 and TGF-β1-induced E-cadherin, α-SMA, Vimentin, N-cadherin mRNA expression in the 16HBE. Transcriptomic analysis of lung tissue from mice with OVA-induced bronchial asthma suggests that ZCL may alleviate asthma symptoms by modulating BPIFA1, HIF3Α, CTXN3, GRFA3, PPEF1, KSR2, and CDSN.

CONCLUSION

ZCL alleviates asthma by suppressing tracheal contractions, inflammation, and epithelial-to-mesenchymal transition. ZCL effect on asthma is likely through the upregulation of BPIFA1 expression thus providing the molecular insight for the treatment of asthma. The findings suggest that ZCL holds promise as a asthma therapeutic approach, and further research is needed to explore its full clinical potential. Future studies should focus on optimizing dosage, evaluating long-term efficacy, and investigating potential synergistic effects with existing treatments to enhance asthma management and patient outcomes.

A systematic pharmacological strategy-based to decode the synergistic mechanism of 7,4'-dihydroxyflavone in combination with vitamin D3 against asthma

ETHNOPHARMACOLOGICAL RELEVANCE

7,4'-dihydroxyflavone (74DHF), extracted from Gancao (Rhizoma Glycyrrhizae), has demonstrated to mediate the asthma pathology, while Vitamin D3 (VD3) plays a role in asthma treatment due to its immunomodulatory effects. However, the potential molecular or systems mechanism of 74DHF in combination with VD3 against asthma has not yet been elucidated.

AIM OF THE STUDY

The current study not only deepens our understanding of the complex synergistic mechanism of 74DHF andVD3 against asthma but also proposes a promising strategy to promote the development of combination therapy.

MATERIALS AND METHODS

This study employed a systems pharmacology-based approach integrating target fishing, data integration, bioinformatics analysis, network analysis, Gene Ontology (GO) enrichment analysis, pathway analysis, and in vitro experiment validation to elucidate the pharmacological mechanisms of the combination of 74DHF and VD3 for asthma treatment.

RESULTS

Our investigation revealed 47 overlapping targets, 20 core targets, 10 optimal common GO processes, and 10 key pathways closely associated with asthma in the combination of 74DHF and VD3. The combined treatment of 74DHF and VD3 inhibited the inflammatory response (TNF-α and IL-6) induced by LPS in macrophages and epithelial to mesenchymal transition (EMT) related genes expression (CDH1 and ACTA2) in bronchial epithelial cells under the stimulation of TGF-β1.

CONCLUSION

The present study deciphered the molecular mechanism of combined therapeutic effect of 74DHF and VD3 on asthma on systemic and cellular level.

Exploring the anti-anaphylaxis potential of natural products: A Review

Allergies are a common health issue affecting many people around the world, especially in developed countries. They occur when the immune system overreacts to substances that are usually harmless. Some common allergic conditions include asthma, sinus infections, skin rashes, food allergies, hay fever, severe allergic reactions, eczema, swelling, and reactions to medications or insect stings. The causes of these allergies are complex and often linked to genetics, which can lead to heightened immune responses known as atopy. Throughout history, plant extracts have been used for various purposes, including medicine and food. In addition, their bioactive compounds show a wide range of beneficial effects, such as reducing allergic reactions, fighting oxidative stress, mast cell stabilizers, and lowering inflammation, highlighting their potential for treating various health conditions. Flavonoids and phenolic compounds are commonly used in anaphylaxis for their potent anti-inflammatory action. This review aims to promote the use of natural products as potential treatments for anaphylaxis. In addition, the discovery of new drugs derived from natural sources holds significant promise for the management of anaphylaxis.

Elevated oxidative stress and steroid insensitivity in patients with asthma and high body fat percentage

BACKGROUND

Obesity is a risk factor for poor asthma control. Previous research suggests that patients with asthma and obesity have reduced responsiveness to corticosteroids. Recent studies indicate that body fat percentage may be more strongly associated with obesity-related diseases compared with body mass index. However, the relationship between body fat percentage and asthma, particularly regarding steroid sensitivity, remains unclear.

OBJECTIVE

To investigate the association between body fat percentage and steroid sensitivity in patients with asthma and elucidate the potential mechanisms underlying this association.

METHODS

Adult patients with asthma were enrolled and categorized into patients with high body fat percentage (HBF) and control groups. Peripheral blood mononuclear cells were isolated from the blood samples. These cells were cultured with dexamethasone followed by stimulation with tumor necrosis factor-α to assess the half-maximal inhibitory concentration of dexamethasone (IC50-Dex). Serum adipocytokines and oxidative stress markers were also measured. The effects of metformin on steroid sensitivity and oxidative stress in peripheral blood mononuclear cells were evaluated ex vivo.

RESULTS

The HBF group exhibited significantly higher IC50-Dex values than the control group. In the HBF group, IC50-Dex correlated with the number of acute exacerbations per year and serum oxidative stress marker levels. Treatment with metformin significantly reduced both IC50-Dex and oxidative stress marker levels in the HBF group.

CONCLUSION

Oxidative stress associated with increased body fat may contribute to impaired steroid sensitivity in patients with asthma. Metformin may improve steroid sensitivity by reducing oxidative stress, suggesting a potential therapeutic approach in this patient population.

Association between exposure to volatile organic compounds and allergic symptoms: Emphasis on the cocktail effect and potential mechanisms of toxicity

Assessment of the influence of volatile organic compounds (VOCs) on allergic symptoms is usually limited to the effect of individual VOC exposure, with fewer substances being considered. Furthermore, the impact of mixed VOC exposure on allergic symptoms has rarely been addressed. This study aimed to investigate the association between mixed VOC exposure and allergic symptoms while identifying key risk factors. A total of 1901 participants from the 2005-2006 National Health and Nutrition Examination Survey (NHANES) were included. Four statistical models were employed to assess the effect of VOC exposure on allergic symptoms. The potential pathways and key targets were identified using the network pharmacology analysis methods. Positive correlations were observed between mixed VOC exposure and wheezing and eczema. N-acetyl-S-(2-carbamoylethyl)-L-cysteine (AAMA) and N-acetyl-s-(3-hydroxypropyl-1-methyl)-L-cysteine (HPMM) were recognized as significant risk factors for wheezing and eczema. The network pharmacology analysis revealed significant enrichments of the PI3K-Akt and MAPK signaling pathways between AAMA and wheezing, as well as significant enrichments of the interleukin (IL)-17 and tumor necrosis factor (TNF) signaling pathways between HPMM and eczema. Consequently, our study suggested that VOC exposure in human results in oxidative stress and inflammatory responses, increasing the risk of allergic symptoms.

KLF12 inhibits lipopolysaccharide-induced inflammatory responses, oxidative stress, pyroptosis, and endoplasmic reticulum stress in human airway epithelial cells through inhibition of the NF-κB pathway

Asthma is a common and frequent chronic disease in pediatrics with obvious pathological features, particularly inflammation, oxidative stress, pyroptosis, and endoplasmic reticulum (ER) stress. Some Krüppel-like factors (KLFs), such as KLF2, KLF4, KLF5, and KLF10, have been reported to be associated with several respiratory diseases, including asthma. However, the role of KLF12 in asthma pathogenesis is unknown. Based on the GEO analysis, KLF12 mRNA expression was reduced in asthma patients. We further assessed the role of KLF12 in protecting airway epithelial cells (BEAS-2B cells) against stimuli using an in vitro model of asthma. The results showed that lipopolysaccharide (LPS) stimulation caused a decrease in KLF12 expression. LPS-induced increase in the mRNA levels of inflammatory cytokines TNF-α, IL-6, and IL-8 were attenuated by KLF12 overexpression. LPS induced the production ROS and MDA and reduced the activities of enzymatic antioxidants SOD, CAT, and GSH-Px, which were prevented by KLF12 overexpression. KLF12 overexpression also blocked LPS-induced pyroptosis, as shown by decreased levels of IL-1β, IL-18, and LDH, as well as downregulated expression levels of pyroptosis-related proteins including NLRP3, ASC, cleaved caspase-1, and GSDMD-N. LPS-induced expression levels of ER stress markers GRP78, CHOP, p-eIF2α, and ATF-4 were inhibited by KLF12 overexpression. In addition, the protective effects of KLF12 on LPS-stimulated cells were enhanced by PDTC, an inhibitor of NF-κB. KLF12 knockdown showed an opposite effect to KLF12 overexpression. These results indicated that KLF12 suppressed LPS-induced inflammatory response, oxidative stress, pyroptosis, and ER stress, which were mediated by the inactivation of the NF-κB pathway.

Defining the Blood Cytokine Profile in Asthma to Understand Asthma Heterogeneity

BACKGROUND

Asthma is a heterogeneous disease characterized by overlapping clinical and inflammatory features.

OBJECTIVE

This study aimed to provide insight into the systemic inflammatory profile in asthma, greater understanding of asthma endotypes and the contribution of genetic risk factors to both.

METHODS

4205 patients with asthma aged 16-60 were recruited from UK centers; serum cytokines were quantified from 708, including cytokines associated with Type 1, 2 and 17 inflammation. 3037 patients were genotyped for 25 single nucleotide polymorphisms associated with moderate-severe asthma.

RESULTS

Serum cytokines associated with Th2 inflammation showed high coordinated expression for example, IL-4/IL-5 (R2 = 0.513). The upper quartile of the serum cytokine data identified 43.7% of patients had high levels for multiple Th2 cytokines. However, the groups defined by serum cytokine profile were not clinically different. Childhood-onset asthma was characterized by elevated total IgE, allergic rhinitis and dermatitis. Exacerbation prone patients had a higher BMI, smoking pack-years, asthma control questionnaire score and reduced lung function. Patients with blood eosinophils of > 300 cells/µL had elevated total IgE and lower smoking pack-years. None of these groups had a differential serum cytokine profile. Asthma risk alleles for; rs61816764 (FLG) and rs9303277 (IKFZ3) were associated with childhood onset disease (p = 2.67 × 10- 4 and 2.20 × 10- 7; retrospectively). No genetic variant was associated with cytokine levels.

CONCLUSION

Systemic inflammation in asthma is complex. Patients had multiple overlapping inflammatory profiles suggesting several disease mechanisms. Genetic risk factors for moderate-severe asthma confirmed previous associations with childhood onset of asthma.

The Therapeutic Potential of Myo-Inositol in Managing Patients with Respiratory Diseases

Respiratory diseases are major health concerns worldwide. Chronic respiratory diseases (CRDs) are the third leading cause of death worldwide and some of the most common are chronic obstructive pulmonary disease (COPD), asthma, occupational lung diseases, and pulmonary hypertension. Despite having different etiology and characteristics, these diseases share several features, such as a persistent inflammatory state, chronic oxidative stress, impaired mucociliary clearance, and increased alveolar surface tension. CRDs are not curable; however, various forms of treatment, that help restore airway patency and reduce shortness of breath, can improve daily life for people living with these conditions. In this regard myo-inositol may represent a valid therapeutic adjuvant approach due to its properties. Being a redox balancer, an inflammation modulator, and, most importantly, a component of pulmonary surfactant, it may improve lung function and counteract symptoms associated with respiratory diseases, as recently evidenced in patients with COPD, COVID-19, asthma, and bronchiectasis. The aim of this review is to evaluate the potential therapeutic role of myo-inositol supplementation in the management of patients with respiratory diseases.

Lipid-lowering drug targets associated with risk of respiratory disease: a Mendelian randomization study

BACKGROUND

Observational studies have identified a possible connection between lipid-lowering medications and respiratory illnesses. However, it remains unclear whether lipid-lowering drugs is causative for respiratory diseases, and we aimed to answer this question.

METHODS

We performed Mendelian randomization (MR) analyses by integrating data from genome-wide association studies (GWAS). Three statistical approaches were employed for MR analysis: inverse variance weighting (IVW), MR-Egger, and weighted median. The purpose was to evaluate the causal relationships between 10 drug targets that lower lipid levels and the likelihood of developing 7 respiratory diseases. Additional sensitivity analyses were conducted to ensure the robustness and validity of the results.

RESULTS

After adjusting for multiple testing, our MR analysis identified APOB (odd ratios [OR]: 0.86; 95% confidence interval [CI]: 0.77 to 0.97; PIVW = 0.01) and PCSK9 (OR: 0.84; 95% CI: 0.72 to 0.97; PIVW = 0.02) as significant risk targets for asthma. Additionally, LDLR was found to be a significant risk target for chronic obstructive pulmonary disease (OR: 0.81; 95% CI: 0.67 to 0.98; PIVW = 0.03). The sensitivity analysis validated no proof of heterogeneity or pleiotropy amongst the mentioned results.

CONCLUSIONS

Our findings suggest a likely causal relationship between respiratory diseases and lipid-lowering drug targets. Further mechanistic and clinical research is needed to confirm and validate these findings.

Peripheral blood miRNAs are associated with airflow below threshold in children with asthma

BACKGROUND

MicroRNAs (miRNAs) are crucial post-transcriptional regulators involved in inflammatory diseases, such as asthma. Poor lung function and airflow issues in childhood are linked to the development of chronic obstructive pulmonary disease (COPD) in adulthood.

METHODS

We analyzed small RNA-Seq data from 365 peripheral whole blood samples from the Genetics of Asthma in Costa Rica Study (GACRS) for association with airflow levels measured by FEV1/FVC. Differentially expressed (DE) miRNAs were identified using DESeq2 in R, adjusting for covariates and applying a 10% false discovery rate (FDR). The analysis included 361 samples and 649 miRNAs. The two DE miRNAs were further tested for association with airflow obstruction in a study of adult former smokers with and without COPD.

RESULTS

We found 1 upregulated and 1 downregulated miRNA in participants with airflow below the threshold compared to those above it. In the adult study, the same miRNAs were upregulated and downregulated in individuals with FEV1/FVC < 0.7 versus those with FEV1/FVC > 0.7, showing suggestive statistical evidence. The target genes of these miRNAs were enriched for PI3K-Akt, Hippo, WNT, MAPK, and focal adhesion pathways.

CONCLUSIONS

Two differentially expressed miRNAs were associated with airflow levels in children with asthma and airflow obstruction in adults with COPD. This suggests that shared genetic regulatory systems may influence childhood airflow and contribute to adulthood airflow obstruction.

Asthma Biologics Across the T2 Spectrum of Inflammation in Severe Asthma: Biomarkers and Mechanism of Action

Airway inflammation, a hallmark feature of asthma, drives many canonical features of the disease, including airflow limitation, mucus plugging, airway remodeling, and hyperresponsiveness. The T2 inflammatory paradigm is firmly established as the dominant mechanism of asthma pathogenesis, largely due to the success of inhaled corticosteroids and biologic therapies targeting components of the T2 pathway, including IL-4, IL-5, IL-13, and thymic stromal lymphopoietin (TSLP). However, up to 30% of patients may lack signatures of meaningful T2 inflammation (ie, T2 low). In T2-low asthma patients, T2 inflammation may be masked due to anti-inflammatory treatments or may be highly variable depending on exposure to common asthma triggers such as allergens, respiratory infections, and smoke or pollution. The epithelium and epithelial cytokines (TSLP, IL-33) are increasingly recognized as upstream drivers of canonical T2 pathways and as modulators of various effector cells, including mast cells, eosinophils, and neutrophils, which impact the pathological manifestations of airway smooth muscle hypertrophy, hypercontractility, and airway hyperresponsiveness. Approved biologics for severe asthma target several distinct mechanisms of action, leading to differential effects on the spectrum of T2 inflammation, inflammatory biomarkers, and treatment efficacy (reducing asthma exacerbations, improving lung function, and diminishing symptoms). The approved anti-asthma biologics primarily target T2 immune pathways, with little evidence suggesting a benefit of targeting non-T2 asthma-associated mediators. Indeed, many negative results challenge current assumptions about the etiology of non-T2 asthma and raise doubts about the viability of targeting popular alternative inflammatory pathways, such as T17. Novel data have emerged from the use of biologics to treat various inflammatory mediators and have furthered our understanding of pathogenic mechanisms that drive asthma. This review discusses inflammatory pathways that contribute to asthma, quantitatively outlines effects of available biologics on biomarkers, and summarizes data and challenges from clinical trials that address non-T2 mechanisms of asthma.

Iron-related Genes and Proteins Involved in Iron Homeostasis in Animal Models of Allergic Asthma: A Systematic Review

The involvement of the immune oxidative stress response in the pathophysiology and pathogenesis of allergic asthma is well documented. However, reports on the role of iron homeostasis in allergic asthma is scarce. Therefore, this study aims to identify iron-related genes and proteins in mouse models of allergic asthma. Related articles were identified from SCOPUS and Web of Science databases. The article search was limited to publications in English, within a 10-year period (2014 - 2023, up to 16 August 2023) and original/research papers. All identified articles were screened for eligibility using the inclusion and exclusion criteria. All eligible articles were quality appraised prior to data extraction. Five studies were selected for data extraction. Based on the extracted data, three themes and seven subthemes related to iron homeostasis were identified. The type of samples and analytical methods used were also identified. In conclusion, our study elucidates that iron-related proteins are regulated in animal models of allergic asthma. However, the currently available data do not allow us to conclude whether the disease model resulted in iron accumulation or depletion. Therefore, further studies with other related markers should be conducted.

Amelioration of Inflammation in Rats with Experimentally Induced Asthma by Spenceria ramalana Trimen Polyphenols via the PI3K/Akt Signaling Pathway

Asthma is a chronic inflammatory respiratory disease that affects millions globally and poses a serious public health challenge. Current therapeutic strategies, including corticosteroids, are constrained by variable patient responses and adverse effects. In this study, a polyphenolic extract derived from the Tibetan medicinal plant Spenceria ramalana Trimen (SRT) was employed and shown to improve experimentally (ovalbumin + cigarette smoke, OVA + CS) induced asthma in rats. Initially, the potential therapeutic mechanism of the polyphenolic components in SRT on OVA + CS-induced asthma was predicated by network pharmacology analysis. Subsequently, in vivo experiments identified that SRT polyphenols exhibit significant anti-asthmatic activities, primarily mediated by lowering inflammatory cell counts such as the WBC (white blood cell), eosinophils, and neutrophils, decreasing the expression of inflammatory cytokines (IL-4, IL-5, IL-13, and TNF-α), alleviating lung histological damage (reduced inflammation, collagen deposition, and mucus secretion), and enhancing the epithelial barrier integrity (upregulation of ZO-1, occludin, and claudin-1). Additionally, SRT polyphenols downregulated the PI3K/Akt (Phosphoinositide 3-kinase/protein kinase B) signaling pathway, improved gut microbiota disruption, and regulated fecal metabolites (glucose-6-glutamate, PS (16:0/0:0), 8-aminocaprylic acid, galactonic acid, Ascr#10, 2,3,4,5,6,7-hexahydroxyheptanoic acid, phosphodimethylethanolamine, muramic acid, 9-oxohexadeca-10e-enoic acid, and sedoheptulose) in asthmatic rats. In conclusion, SRT polyphenols exerted multifaceted protective effects against OVA + CS-induced asthma in rats, highlighting their potential value in preventing asthma via the PI3K/Akt signaling pathway.

Luteolin alleviates airway remodeling in asthma by inhibiting the epithelial-mesenchymal transition via β-catenin regulation

BACKGROUND

Asthma is a prevalent long-term inflammatory condition that causes airway inflammation and remodeling. Increasing evidence indicates that epithelial-mesenchymal transition (EMT) holds a prominent implication in airway reconstruction in patients with asthma. Flavonoids obtained from Chinese Materia Medica (CMM), such as Luteolin (Lut), exhibit various beneficial effects in various asthma models. Lut has been shown to mitigate various asthma symptoms, including airway inflammation, hyperresponsiveness, bronchoconstriction, excessive mucus production, pulmonary autophagy, and neutrophilic asthma. However, whether flavonoids can suppress EMT-associated airway remodeling in asthma and the fundamental mechanisms involved remain unclear, with no studies specifically addressing Lut in this context.

PURPOSE

To evaluate the inhibition of airway remodeling in asthma by Lut and its potential mechanisms, while examining the significance of β-catenin in this process through cellular and animal studies.

METHODS

A BEAS-2B cell model stimulated by lipopolysaccharide (LPS) was established in vitro. Wound closure and Transwell assays were utilized to assess the cellular migratory ability. EMT- and fibrosis-related markers in LPS-stimulated cells were evaluated using RT-qPCR and western blotting. The status of the β-catenin/E-cadherin and β-catenin destruction complexes was evaluated using western blotting, immunofluorescence (IF) staining, and co-immunoprecipitation (Co-IP) analysis. The regulatory function of Lut in β-catenin-dependent EMT was further validated by β-catenin overexpression with adenovirus transduction and siRNA-mediated knockdown of β-catenin. Moreover, the counts of different types of bronchoalveolar lavage fluid (BALF) inflammatory cells from mice with asthma induced by ovalbumin (OVA) were evaluated in vivo using Congo red staining. Hematoxylin and eosin (H&E), Masson's trichrome, and periodic acid-Schiff (PAS) staining were used to evaluate collagen deposition, mucus production, and inflammation in murine lung tissues. Western blotting and immunohistochemistry (IHC) assays were used to assess EMT- and fibrosis-related markers in the lung tissues in vivo.

RESULT

Six naturally derived flavonoids, including Lut, attenuated cell migration and prevented EMT in LPS-treated BEAS-2B cells. Moreover, Lut suppressed TGF-β1, MMP-9, fibronectin (FN), and α-smooth muscle actin (α-SMA) levels in LPS-stimulated BEAS-2B cells. Additionally, Lut downregulated the levels of β-catenin by modulating the β-catenin/E-cadherin and β-catenin destruction complexes, highlighting the pivotal role of β-catenin in EMT inhibition by Lut in LPS-stimulated BEAS-2B cells. Furthermore, Lut suppressed airway inflammation and attenuated EMT-associated airway remodeling through β-catenin blockade in OVA-induced asthmatic mice. The bronchial wall thickness notably reduced from 37.24 ± 4.00 μm in the asthmatic model group to 30.06 ± 4.40 μm in the Lut low-dose group and 24.69 ± 2.87 μm in the Lut high-dose group.

CONCLUSION

According to our current understanding, this research is the first to reveal that Lut diminishes airway remodeling in asthma by inhibiting EMT via β-catenin regulation, thereby filling a research gap concerning Lut and flavonoids. These results provide a theoretical basis for treating asthma with anti-asthmatic CMM, as well as a candidate and complementary therapeutic approach to treat asthma.

Comparison of Jinzhen oral liquid and ambroxol hydrochloride and clenbuterol hydrochloride oral solution in the treatment of acute bronchitis in children: A multicenter, non-inferiority, prospective, randomized controlled trial

The comparison between traditional Chinese medicine Jinzhen oral liquid (JZOL) and Western medicine in treating children with acute bronchitis (AB) showed encouraging outcomes. This trial evaluated the efficacy and safety of the JZOL for improving cough and expectoration in children with AB. 480 children were randomly assigned to take JZOL or ambroxol hydrochloride and clenbuterol hydrochloride oral solution for 7 days. The primary outcome was time-to-cough resolution. The median time-to-cough resolution in both groups was 5.0 days and the antitussive onset median time was only 1 day. This randomized controlled trial showed that JZOL was not inferior to cough suppressant and phlegm resolving western medicine in treating cough and sputum and could comprehensively treat respiratory and systemic discomfort symptoms. Combined with clinical trials, the mechanism of JZOL against AB was uncovered by network target analysis, it was found that the pathways in TRP channels like IL-1β/IL1R/TRPV1/TRPA1, NGF/TrkA/TRPV1/TRPA1, and PGE2/EP/PKA/TRPV1/TRPA1 might play important roles. Animal experiments further confirmed that inflammation and the immune regulatory effect of JZOL in the treatment of AB were of vital importance and TRP channels were the key mechanism of action.

Green carbon dots derived from Zingiberis Rhizoma Carbonisatum alleviate ovalbumin-induced allergic rhinitis

Background

Allergic rhinitis (AR) affects up to 40% of the population, leading to significant healthcare expenditures. Current mainstream treatments, while effective, can lead to side effects and do not address the underlying immunological imbalances. Zingiberis Rhizoma Carbonisatum (ZRC), the partially charred product of Zingiberis Rhizoma (ZR), has been widely used clinically in China since ancient times to treat respiratory disorders.

Methods

Inspired by the similarity between high-temperature pyrolysis and carbonization processing of herbal medicine, ZRC derived CDs (ZRC-CDs) were extracted and purified through several procedures. Then, the physicochemical characteristics of CDs were delineated through a suite of characterization methods. Moreover, our investigation zeroed in on elucidating the ameliorative impacts of CDs on ovalbumin-induced rat models alongside their underlying mechanisms.

Results

ZRC-CDs with particle sizes ranging from 1.0 to 3.5 nm and rich surface functional groups. Additionally, we observed that ZRC-CDs significantly attenuated nasal symptoms and pathological damage in ovalbumin-induced AR rats, and modulated lipid metabolism and type 2 inflammatory responses. They also inhibit PI3K/AKT and JAK/STAT pathways, which are associated with metabolism and inflammation. Importantly, ZRC-CDs demonstrated high biocompatibility, underscoring their potential as a novel therapeutic agent.

Conclusion

ZRC-CDs offer a promising alternative for AR treatment and could help facilitate broader clinical use of the ZRC. In addition, the exploration of the inherent bioactivity of CDs can help to broaden their biological applications.

The volatile oil of Hyssopus cuspidatus Boriss. (HVO) ameliorates OVA-induced allergic asthma via inhibiting PI3K/Akt/JNK/P38 signaling pathway and maintaining airway barrier integrity

ETHNOPHARMACOLOGICAL RELEVANCE

Hyssopus cuspidatus Boriss., a classic Uyghur medicine, is used to treat inflammatory lung diseases such as asthma. But the therapeutic effect and mechanism of the volatile oil of Hyssopus cuspidatus Boriss.(HVO) in asthma therapy remain unclear.

AIM OF THE STUDY

We aim to characterize the constituents of HVO, investigate the therapeutic effect in OVA-induced allergic asthmatic mice and further explore the molecular mechanism.

MATERIALS AND METHODS

In this study, we applied two-dimensional gas chromatography quadrupole time-of-flight mass spectrometry (GC × GC-QTOF MS) to identify the ingredients of HVO. We established OVA-induced asthmatic model to investigate the therapeutic effect of HVO. To further explore the potential molecular pathways, we used network pharmacology approach to perform GO and KEGG pathways enrichment, and then built an ingredient-target-pathway network to identify key molecular pathways. Finally, LPS-induced RAW 264.7 macrophages and OVA-induced asthmatic model were used to validate the potential signaling pathways.

RESULTS

GC × GC-QTOF MS analysis revealed the presence of 123 compounds of HVO. The sesquiterpenes and monoterpenes are the main constituents. The in vivo study indicated that HVO suppressed OVA-induced eosinophilic infiltration in lung tissues, inhibited the elevation of IgE, IL-4, IL-5, and IL-13 levels, downregulated the expressions of phosphorylated PI3K, Akt, JNK and P38, and maintained epithelial barrier integrity via reducing the degradation of occludin, Zo-1, Zo-2, and E-cadherin. The in vitro study also revealed an inhibition of NO release and downregulation of phosphorylated PI3K, Akt, JNK and P38 levels.

CONCLUSION

HVO alleviates airway inflammation in OVA-induced asthmatic mice by inhibiting PI3K/Akt/JNK/P38 signaling pathway and maintaining airway barrier integrity via reducing the degradation of occludin, Zo-1, Zo-2, and E-cadherin.

Airway proteomics reveals broad residual anti-inflammatory effects of prednisolone in mepolizumab-treated asthma

BACKGROUND

Mepolizumab is an anti-IL-5 mAb treatment for severe eosinophilic asthma that reduces asthma exacerbations. Residual airway inflammation with mepolizumab therapy may lead to persistent exacerbations. Oral corticosteroids remain the main treatment for these residual exacerbations.

OBJECTIVE

Our study aimed to explore the corticosteroid responsiveness of airway inflammation after mepolizumab treatment to find potentially treatable inflammatory mechanisms beyond the IL-5 pathway.

METHODS

The MAPLE trial was a multicenter, randomized, double-blind, placebo-controlled, crossover study of 2 weeks of high-dose oral prednisolone treatment at stable state in 27 patients treated with mepolizumab for severe eosinophilic asthma. We analyzed paired sputum (n = 16) and plasma (n = 25) samples from the MAPLE trial using high-throughput Olink proteomics. We analyzed additional sputum proteins using ELISA.

RESULTS

In patients receiving mepolizumab, prednisolone significantly downregulated sputum proteins related to type 2 inflammation and chemotaxis including IL-4, IL-5, IL-13, CCL24, CCL26, EDN, CCL17, CCL22, OX40 receptor, FCER2, and the ST2 receptor. Prednisolone also downregulated cell adhesion molecules, prostaglandin synthases, mast cell tryptases, MMP1, MMP12, and neuroimmune mediators. Neutrophilic pathways were upregulated. Type 2 proteins were also downregulated in plasma, combined with IL-12, IFN-γ, and IP-10. IL-10 and amphiregulin were upregulated.

CONCLUSIONS

At stable state, prednisolone has broad anti-inflammatory effects on top of mepolizumab. These effects are heterogeneous and may be clinically relevant in residual exacerbations.

Diverse Cytokines Secreted by Adipocyte in Linking Cardio-Metabolic Disorder and SLE

Systemic lupus erythematosus (SLE) is a multi-factorial autoimmune-mediated disease with hyper-stimulation of immune cells especially the T lymphocytes. By this method, it might facilitate the systematic damages in multiple tissues and organs. Otherwise, SLE is also correlated with diverse cardio-metabolic comorbidities, including dyslipidemia, insulin resistance, and hypertension. It is worth-noting that the risk of cardio-metabolic disorders is significantly higher compared with the healthy patients which was reported as approximately one-third of SLE patients were proved as obesity. Notably, current focus is shifting to implementing cardio-metabolic protective strategies as well as elucidating underlying mechanisms of lupus-mediated obese status. On the other hand, adipocyte, as the most abundant endocrine cell in fat tissue, are dysfunctional in obese individuals with aberrant secretion of adipokines. It is proposing that the adipokine might link the pathology of cardio-metabolic disorders and SLE, whereas the related mechanism is complicated. In the current review, the functions of adipokine and the potential mechanisms by which the adipokine link cardio-metabolic disorders and SLE was well listed. Furthermore, the recommendations, which identify the adipokine as the potential therapeutic targets for the treatment of cardio-metabolic disorders and SLE, were also summarized.

Roles of Exosomal miRNAs in Asthma: Mechanisms and Applications

Asthma is a chronic inflammatory disorder of the airways, characterized by a complex interplay of genetic, environmental, and immunological factors that contribute to its onset and progression. Recent advances in researches have illuminated the critical role of exosomal microRNAs (miRNAs) in the pathogenesis and development of asthma. Exosomes are nano-sized extracellular vesicles that facilitate intercellular communication by transporting a variety of bioactive molecules, including miRNAs, and play a crucial role in regulating gene expression and immune responses, which are central to the inflammatory processes underlying asthma. Exosomal miRNAs are emerging as key players in asthma due to their involvement in various aspects of the disease, including the regulation of inflammation, airway hyperresponsiveness, and remodeling. Their ability to influence the behavior of target cells and tissues makes them valuable both as diagnostic biomarkers and as potential therapeutic targets. This review aims to provide a comprehensive overview of the biogenesis of exosomes, the functional roles of exosomal miRNAs in asthma, and their clinical potential. It will explore the mechanisms by which these miRNAs contribute to asthma pathophysiology, discuss their utility in diagnosing and monitoring the disease, and highlight ongoing research efforts to harness their therapeutic potential.

A Review on Asthma and Allergy: Current Understanding on Molecular Perspectives

Asthma, a complex disease characterized by persistent airway inflammation, remains an urgent global health concern. We explored the critical role of allergic biomarkers and dysregulated immune system in asthma through an extensive literature review in databases such as Web of Science, PubMed, EMBASE, Scopus, and Google Scholar. This review summarizes the growing data on the pivotal role of allergic biomarkers and dysregulated immune system in the development and evolution of asthma. Recent studies have uncovered several biomarkers that elucidate intrinsic allergic mechanisms in individuals with asthma. This article highlights these biomarkers' potential in predicting asthma onset, assessing its intensity, guiding therapeutic interventions, and tracking disease progression. We also explore the innovative therapeutic prospects arising from the convergence of allergy and dysregulated immune system in asthma and emphasize the potential for precision medicine approaches. Understanding allergic biomarkers intertwined with a dysregulated immune system heralds a new era in asthma treatment and points to improved and individualized treatment modalities.

Impact of SDF-1 and AMD3100 on Hair Follicle Dynamics in a Chronic Stress Model

Chronic stress is a common cause of hair loss, involving inflammatory responses and changes in cellular signaling pathways. This study explores the mechanism of action of the SDF-1/CXCR4 signaling axis in chronic stress-induced hair loss. The research indicates that SDF-1 promotes hair follicle growth through the PI3K/Akt and JAK/STAT signaling pathways. Transcriptome sequencing analysis was conducted to identify differentially expressed genes in the skin of normal and stressed mice, with key genes SDF-1/CXCR4 selected through machine learning and a protein-protein interaction network established. A chronic stress mouse model was created, with injections of SDF-1 and AMD3100 administered to observe hair growth, weight changes, and behavioral alterations and validate hair follicle activity. Skin SDF-1 concentrations were measured, differentially expressed genes were screened, and pathways were enriched. Activation of the PI3K/Akt and JAK/STAT signaling pathways was assessed, and siRNA technology was used in vitro to inhibit the expression of SDF-1 or CXCR4. SDF-1 promoted hair follicle activity, with the combined injection of SDF-1 and AMD3100 weakening this effect. The activation of the PI3K/Akt and JAK/STAT signaling pathways was observed in the SDF-1 injection group, confirmed by Western blot and immunofluorescence. Silencing SDF-1 through siRNA-mediated inhibition reduced cell proliferation and migration abilities. SDF-1 promotes hair growth in chronic stress mice by activating the PI3K/Akt and JAK/STAT pathways, an effect reversible by AMD3100. The SDF-1/CXCR4 axis may serve as a potential therapeutic target for stress-induced hair loss.

Eosinophils as drivers of bacterial immunomodulation and persistence

Traditionally, eosinophils have been linked to parasitic infections and pathological disease states. However, emerging literature has unveiled a more nuanced and intricate role for these cells, demonstrating their key functions in maintaining mucosal homeostasis. Eosinophils exhibit diverse phenotypes and exert multifaceted effects during infections, ranging from promoting pathogen persistence to triggering allergic reactions. Our investigations primarily focus on Bordetella spp., with particular emphasis on Bordetella bronchiseptica, a natural murine pathogen that induces diseases in mice akin to pertussis in humans. Recent findings from our published work have unveiled a striking interaction between B. bronchiseptica and eosinophils, facilitated by the btrS-mediated mechanism. This interaction serves to enhance pathogen persistence while concurrently delaying adaptive immune responses. Notably, this role of eosinophils is only noted in the absence of a functional btrS signaling pathway, indicating that wild-type B. bronchiseptica, and possibly other Bordetella spp., possess such adeptness in manipulating eosinophils that the true function of these cells remains obscured during infection. In this review, we present the mounting evidence pointing toward eosinophils as targets of bacterial exploitation, facilitating pathogen persistence and fostering chronic infections in diverse mucosal sites, including the lungs, gut, and skin. We underscore the pivotal role of the master regulator of Bordetella pathogenesis, the sigma factor BtrS, in orchestrating eosinophil-dependent immunomodulation within the context of pulmonary infection. These putative convergent strategies of targeting eosinophils offer promising avenues for the development of novel therapeutics targeting respiratory and other mucosal pathogens.

Saffron (Crocus sativus) and its constituents in ovalbumin-induced asthma model: a preclinical systematic review and meta-analysis

Background

Animal and human studies have demonstrated that the saffron and the active components of saffron, including crocin, crocetin, and safranal, possess anti-inflammatory, antioxidant, and immunomodulatory properties. In this meta-analysis, the preclinical evidence and potential mechanism of saffron were explored in an animal model of ovalbumin-induced asthma.

Methods

Studies related to saffron and its constituents in an animal model of ovalbumin-induced asthma from the beginning to March 2024 were searched from Scopus, PubMed, and Web of Science databases. The methodological quality of the studies was evaluated using the 15-item CAMARADES checklist. Data analysis was performed using STATA software version 17.

Results

Thirteen studies with 536 animals (268 animals in the intervention group and 268 animals in the ovalbumin-induced group) were analyzed. The meta-analysis findings demonstrated that saffron and its constituents played a significant role in reducing total WBC, eosinophil, lymphocyte, and monocyte counts. Moreover, saffron showed a significant decrease in the levels of IL-4, IL-5, IL-13, IgE, histamine, endothelin, nitric oxide, and nitrite. Moreover, saffron was found to elevate EC50 thresholds and lower maximum response rates in experimental animals. The analysis revealed a significant identification of modulation in endoplasmic reticulum (ER) stress markers and miRNAs pathways.

Conclusion

Saffron and its components may impact ovalbumin-induced asthma model in animals through anti-inflammatory, antioxidant, and immunomodulatory pathways, as well as improving pulmonary function and modulating ER stress markers and miRNAs pathways. As a result, saffron should be considered for further clinical trials in individuals suffering from asthma.

Anti-Allergic and Anti-Inflammatory Signaling Mechanisms of Natural Compounds/Extracts in In Vitro System of RBL-2H3 Cell: A Systematic Review

Various extracts are tested for anti-allergic or anti-inflammatory properties on in vitro models. RBL-2H3 cells are widely used in allergic or immunological studies. FCεRI and its downstream signaling cascades, such as MAPK, NF-κB, and JAK/STAT signaling pathways, are important allergic or inflammatory signaling mechanisms in mast and basophil cells. This systematic review aims to study common signaling pathways of the anti-allergic or anti-inflammatory compounds on RBL-2H3 cells. We selected the relevant research articles published after 2015 from the PubMed, Scopus, Science Direct and Web of Science databases. The risk of bias of the studies was assessed based on the modified CONSORT checklist for in vitro studies. The cell lines, treatments, assay, primary findings, and signaling pathways on RBL-2H3 cells were extracted to synthesize the results. Thirty-eight articles were included, and FCεRI and its downstream pathways, such as Lyn, Sky, PLCγ, and MAPK, were commonly studied. Moreover, the JAK/STAT pathway was a potential signaling mechanism in RBL-2H3 cells. However, the findings based on RBL-2H3 cells needed to be tested along with human mast cells to confirm its relevance to human health. In conclusion, a single plant extract may act as an anti-inflammatory reagent in RBL-2H3 cells via multiple signaling pathways besides the MAPK signaling pathway.

Body Weight and Allergic Asthma: A Narrative Review

Obesity is a known risk factor for asthma development, progression, and exacerbation. Nevertheless, the underlying pathophysiological mechanisms explaining how obesity contributes to the development and progression of asthma have yet to be established. Here, we review human studies examining the associations between asthma and obesity, focusing on the literature from the past 10 years. Overall, current evidence suggests that while both asthma and obesity are complex diseases with significant heterogeneity, they both share various features of chronic inflammation. Furthermore, the interactions between asthma and obesity likely involve allergen-specific T helper type 2 (type 2) immune responses, as well as diverse non-type 2 inflammatory pathways. However, despite considerable progress, studies to date have not definitively elucidated the mechanisms that account for the observed association. A large-scale population-based study combined with translational immunological research, including targeted asthma therapies and pharmacological weight loss therapies, may be required to properly dissect the details of obesity-related asthma pathophysiology.

Targeted inhibition of m6A demethylase FTO by FB23 attenuates allergic inflammation in the airway epithelium

Epithelial cells play a crucial role in asthma, contributing to chronic inflammation and airway hyperresponsiveness. m6A modification, which involves key proteins such as the demethylase fat mass and obesity-associated protein (FTO), is crucial in the regulation of various diseases, including asthma. However, the role of FTO in epithelial cells and the development of asthma remains unclear. In this study, we investigated the demethylase activity of FTO using a small-molecule inhibitor FB23 in epithelial cells and allergic inflammation in vivo and in vitro. We examined the FTO-regulated transcriptome-wide m6A profiling by methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA-seq under FB23 treatment and allergic inflammation conditions. Immunofluorescence staining was performed to assess the tissue-specific expression of FTO in asthmatic bronchial mucosa. We demonstrated that FB23 alleviated allergic inflammation in IL-4/IL-13-treated epithelial cells and house dust mite (HDM)-induced allergic airway inflammation mouse model. The demethylase activity of FTO contributed to the regulation of TNF-α signaling via NF-κB and epithelial-mesenchymal transition-related pathways under allergic inflammation conditions in epithelial cells. FTO was expressed in epithelial, submucosal gland, and smooth muscle cells in human bronchial mucosa. In conclusion, FB23-induced inhibition of FTO alleviates allergic inflammation in epithelial cells and HDM-induced mice, potentially through diverse cellular processes and epithelial-mesenchymal transition signaling pathways, suggesting that FTO is a potential therapeutic target in asthma management.

Beyond CAR-T: The rise of CAR-NK cell therapy in asthma immunotherapy

Asthma poses a major public health burden. While existing asthma drugs manage symptoms for many, some patients remain resistant. The lack of a cure, especially for severe asthma, compels exploration of novel therapies. Cancer immunotherapy successes with CAR-T cells suggest its potential for asthma treatment. Researchers are exploring various approaches for allergic diseases including membrane-bound IgE, IL-5, PD-L2, and CTLA-4 for asthma, and Dectin-1 for fungal asthma. NK cells offer several advantages over T cells for CAR-based immunotherapy. They offer key benefits: (1) HLA compatibility, meaning they can be used in a wider range of patients without the need for matching tissue types. (2) Minimal side effects (CRS and GVHD) due to their limited persistence and cytokine profile. (3) Scalability for "off-the-shelf" production from various sources. Several strategies have been introduced that highlight the superiority and challenges of CAR-NK cell therapy for asthma treatment including IL-10, IFN-γ, ADCC, perforin-granzyme, FASL, KIR, NCRs (NKP46), DAP, DNAM-1, TGF-β, TNF-α, CCL, NKG2A, TF, and EGFR. Furthermore, we advocate for incorporating AI for CAR design optimization and CRISPR-Cas9 gene editing technology for precise gene manipulation to generate highly effective CAR constructs. This review will delve into the evolution and production of CAR designs, explore pre-clinical and clinical studies of CAR-based therapies in asthma, analyze strategies to optimize CAR-NK cell function, conduct a comparative analysis of CAR-T and CAR-NK cell therapy with their respective challenges, and finally present established novel CAR designs with promising potential for asthma treatment.

TIM-3-driven macrophage polarisation is associated to recalcitrant chronic rhinosinusitis with nasal polyps

Objective

This study evaluated the expression of TIM-3 and its influence on macrophage polarisation in recalcitrant chronic rhinosinusitis with nasal polyps (CRSwNP).

Methods

We detected TIM-3 expression in serum and tissue samples of healthy controls (HC), primary CRSwNP, and patients with recurrent CRSwNP. Macrophage markers were detected among three groups, and their correlations with TIM-3 levels were examined. Macrophages from circulating blood were collected and used to examine the impact of TIM-3 on polarisation in vitro.

Results

TIM-3 levels were enhanced in the CRSwNP group compared to the HC group. Tissue immunofluorescence revealed elevated TIM-3 expression in patients with CRSwNP, and patients with multiple recurrences exhibited higher TIM-3 levels compared to their first recurrence and baseline levels. Tissue CD163 and CD206 levels were higher in recurrent CRSwNP in comparison with primary cases and HCs, and had a positive correlation with TIM-3 levels. TIM-3 overexpression promoted M2 polarisation and enhanced TGF-β1 and IL-10 secretion.

Conclusions

TIM-3 expression was enhanced in patients with CRSwNP, especially in those undergoing revision surgeries. TIM-3 may be a novel biomarker for recalcitrant CRSwNP. TIM-3-driven M2 polarisation might be involved in the mechanisms of recurrent CRSwNP.

TRIM47 promotes HDM-induced bronchial epithelial pyroptosis by regulating NEMO ubiquitination to activate NF-κB/NLRP3 signaling

Asthma is an inflammatory disease. Airway epithelial cell pyroptosis and cytokine secretion promote asthma progression. Tripartite motif 47 (TRIM47) belongs to the E3 ubiquitin ligase family and is associated with apoptosis and inflammation in a range of diseases. However, the role of TRIM47 in asthma has not been explored. In this study, the human bronchial epithelial cell line BEAS-2B was treated with house dust mite (HDM) and TRIM47 expression was detected by RT-qPCR and Western blot. After transfection with TRIM47 interfering and overexpressing plasmids, the synthesis and secretion of cytokines, as well as pyroptosis-related indicators, were examined. Nuclear factor kappa-B (NF-κB) pathway proteins and nod-like receptor protein 3 (NLRP3) inflammasome were measured to explore the mechanism of TRIM47 action. In addition, the effect of TRIM47 on the level of NF-κB essential modulator (NEMO) ubiquitination was detected by an immunoprecipitation assay. The results showed that TRIM47 was upregulated in HDM-induced BEAS-2B cells and that TRIM47 mediated HDM-induced BEAS-2B cell pyroptosis and cytokine secretion. Mechanistically, TRIM47 promoted the K63-linked ubiquitination of NEMO and facilitated NF-κB/NLRP3 pathway activation. In conclusion, TRIM47 may promote cytokine secretion mediating inflammation and pyroptosis in bronchial epithelial cells by activating the NF-κB/NLRP3 pathway. Therefore, TRIM47 may be a potential therapeutic target for HDM-induced asthma.

AdipoRon, an adiponectin receptor agonist, modulates AMPK signaling pathway and alleviates ovalbumin-induced airway inflammation in a murine model of asthma

Asthma is a long-term disease that causes airways swelling and inflammation and in turn airway narrowing. AdipoRonis an orally active synthetic small molecule that acts as a selective agonist at theadiponectin receptor 1 and 2. The aim of the current study is to delineate the protective effect and the potential underlying mechanism ofadipoRon inairway inflammationinduced byovalbumin (OVA) in comparison withdexamethasone. Adult maleSwiss Albino micewere sensitized to OVA on days 0 and 7, then challenged with OVA on days 14, 15 and 16. AdipoRon was administered orally for 6 days starting from the 11th day till the 16th and 1 h prior to OVA in the challenge days. Obtained results from asthmatic control group showed a significant decrease in serum adiponectin concentration, an increase in inflammatory cell counts inthe bronchoalveolar lavage fluid(BALF), CD68 protein expression, inflammatory cytokine concentration and oxidative stress as well. Administration of adipoRon enhanced antioxidant mechanisms limiting oxidative stress by significantly increasing reduced glutathione (GSH) pulmonary content, decreasing serum lactate dehydrogenase (LDH) together with malondialdehyde (MDA) significant reduction in lung tissue. In addition, it modulated the levels of serum immunoglobulin E (IgE), pro-inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-13, nuclear factor kappa B (NF-κB) and the anti-inflammatory one IL-10 improving lung inflammation as revealed by histopathological evaluation. Furthermore, lung tissue expression of nuclear factor erythroid 2-related factor (Nrf2) and 5'AMP-activated protein kinase (AMPK) were significantly increased adipoRon. Notably, results of adipoRon received group were comparable to those of dexamethasone group. In conclusion, our study demonstrates that adipoRon can positively modulate adiponectin expression with activation of AMPK pathway and subsequent improvement in inflammatory and oxidative signaling.

Cellular metabolism and hypoxia interfacing with allergic diseases

Allergic diseases display significant heterogeneity in their pathogenesis. Understanding the influencing factors, pathogenesis, and advancing new treatments for allergic diseases is becoming more and more vital as currently, prevalence continues to rise, and mechanisms of allergic diseases are not fully understood. The upregulation of the hypoxia response is linked to an elevated infiltration of activated inflammatory cells, accompanied by elevated metabolic requirements. An enhanced hypoxia response may potentially contribute to inflammation, remodeling, and the onset of allergic diseases. It has become increasingly clear that the process underlying immune and stromal cell activation during allergic sensitization requires well-tuned and dynamic changes in cellular metabolism. The purpose of this review is to examine current perspectives regarding metabolic dysfunction in allergic diseases. In the past decade, new technological platforms such as "omic" techniques have been applied, allowing for the identification of different biomarkers in multiple models ranging from altered lipid species content, increased nutrient transporters, and altered serum amino acids in various allergic diseases. Better understanding, recognition, and integration of these alterations would increase our knowledge of pathogenesis and potentially actuate a novel repertoire of targeted treatment approaches that regulate immune metabolic pathways.

Prostaglandin D2 receptor 2 downstream signaling and modulation of type 2 innate lymphoid cells from patients with asthma

Increased production of Prostaglandin D2 (PGD2) is linked to development and progression of asthma and allergy. PGD2 is rapidly degraded to its metabolites, which initiate type 2 innate lymphoid cells (ILC2) migration and IL-5/IL-13 cytokine secretion in a PGD2 receptor 2 (DP2)-dependent manner. Blockade of DP2 has shown therapeutic benefit in subsets of asthma patients. Cellular mechanisms of ILC2 activity in response to PGD2 and its metabolites are still unclear. We hypothesized that ILC2 respond non-uniformly to PGD2 metabolites. ILC2s were isolated from peripheral blood of patients with atopic asthma. ILC2s were stimulated with PGD2 and four PGD2 metabolites (Δ12-PGJ2, Δ12-PGD2, 15-deoxyΔ12,14-PGD2, 9α,11β-PGF2) with or without the selective DP2 antagonist fevipiprant. Total RNA was sequenced, and differentially expressed genes (DEG) were identified by DeSeq2. Differential gene expression analysis revealed an upregulation of pro-inflammatory DEGs in ILC2s stimulated with PGD2 (14 DEGs), Δ12-PGD2 (27 DEGs), 15-deoxyΔ12,14-PGD2 (56 DEGs) and Δ12-PGJ2 (136 DEGs), but not with 9α,11β-PGF2. Common upregulated DEGs were i.e. ARG2, SLC43A2, LAYN, IGFLR1, or EPHX2. Inhibition of DP2 via fevipiprant mainly resulted in downregulation of pro-inflammatory genes such as DUSP4, SPRED2, DUSP6, ETV1, ASB2, CD38, ADGRG1, DDIT4, TRPM2, or CD69. DEGs were related to migration and various immune response-relevant pathways such as "chemokine (C-C motif) ligand 4 production", "cell migration", "interleukin-13 production", "regulation of receptor signaling pathway via JAK-STAT", or "lymphocyte apoptotic process", underlining the pro-inflammatory effects of PGD2 metabolite-induced immune responses in ILC2s as well as the anti-inflammatory effects of DP2 inhibition via fevipiprant. Furthermore, PGD2 and metabolites showed distinct profiles in ILC2 activation. Overall, these results expand our understanding of DP2 initiated ILC2 activity.

Dihydroartemisinin ameliorates experimental autoimmune myasthenia gravis by regulating CD4+ T cells and modulating gut microbiota

BACKGROUND

Dihydroartemisinin (DHA), a derivative and active metabolite of artemisinin, possesses various immunomodulatory properties. However, its role in myasthenia gravis (MG) has not been clearly explored. Here, we investigated the role of DHA in experimental autoimmune myasthenia gravis (EAMG) and its potential mechanisms.

METHODS

The AChR97-116 peptide-induced EAMG model was established in Lewis rats and treated with DHA. Flow cytometry was used to assess the release of Th cell subsets and Treg cells, and 16S rRNA gene amplicon sequence analysis was applied to explore the relationship between the changes in the intestinal flora after DHA treatment. In addition, network pharmacology and molecular docking were utilized to explore the potential mechanism of DHA against EAMG, which was further validated in the rat model by immunohistochemical and RT-qPCR for further validation.

RESULTS

In this study, we demonstrate that oral administration of DHA ameliorated clinical symptoms in rat models of EAMG, decreased the expression level of Th1 and Th17 cells, and increased the expression level of Treg cells. In addition, 16S rRNA gene amplicon sequence analysis showed that DHA restored gut microbiota dysbiosis in EAMG rats by decreasing Ruminococcus abundance and increasing the abundance of Clostridium, Bifidobacterium, and Allobaculum. Using network pharmacology, 103 potential targets of DHA related to MG were identified, and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that PI3K-AKT signaling pathway was related to the treatment of DHA on EAMG. Meanwhile, molecular docking verified that DHA has good binding affinity to AKT1, CASP3, EGFR, and IGF1. Immunohistochemical staining showed that DHA treatment significantly inhibited the phosphorylated expression of AKT and PI3K in the spleen tissues of EAMG rats. In EAMG rats, RT-qPCR results also showed that DHA reduced the mRNA expression levels of PI3K and AKT1.

CONCLUSIONS

DHA ameliorated EAMG by inhibiting the PI3K-AKT signaling pathway, regulating CD4+ T cells and modulating gut microbiota, providing a novel therapeutic approach for the treatment of MG.

Linkage of serum ITIH4 with Th2 signature cytokine, inflammation, exacerbation risk and severity in childhood asthma

Aim: ITIH4 has anti-inflammatory properties toward eosinophilic/neutrophilic inflammation. This study aimed to explore clinical value of ITIH4 in childhood asthma.Materials & methods: Serum ITIH4 and inflammatory cytokines were determined in 120 childhood asthma patients by enzyme-linked immunosorbent assay.Results: In the entire and acute exacerbation patients, ITIH4 positively associated with IFN-γ, but negatively related to proinflammatory cytokines. ITIH4 was lowest in patients with acute exacerbation, followed by chronic persistent, and highest in clinical remission. By receiver-operating characteristic analysis, ITIH4 potentially estimated acute exacerbation asthma risk. Moreover, ITIH4 negatively related to exacerbation severity in acute exacerbation patients.Conclusion: Serum ITIH4 negatively links with Th2 cell signature cytokine, proinflammatory cytokines, exacerbation risk and severity in childhood asthma.

Macrophage-Biomimetic Nanoplatform-Based Therapy for Inflammation-Associated Diseases

Inflammation-associated diseases are very common clinically with a high incidence; however, there is still a lack of effective treatments. Cell-biomimetic nanoplatforms have led to many breakthroughs in the field of biomedicine, significantly improving the efficiency of drug delivery and its therapeutic implications especially for inflammation-associated diseases. Macrophages are an important component of immune cells and play a critical role in the occurrence and progression of inflammation-associated diseases while simultaneously maintaining homeostasis and modulating immune responses. Therefore, macrophage-biomimetic nanoplatforms not only inherit the functions of macrophages including the inflammation tropism effect for targeted delivery of drugs and the neutralization effect of pro-inflammatory cytokines and toxins via membrane surface receptors or proteins, but also maintain the functions of the inner nanoparticles. Macrophage-biomimetic nanoplatforms are shown to have remarkable therapeutic efficacy and excellent application potential in inflammation-associated diseases. In this review, inflammation-associated diseases, the physiological functions of macrophages, and the classification and construction of macrophage-biomimetic nanoplatforms are first introduced. Next, the latest applications of different macrophage-biomimetic nanoplatforms for the treatment of inflammation-associated diseases are summarized. Finally, challenges and opportunities for future biomedical applications are discussed. It is hoped that the review will provide new ideas for the further development of macrophage-biomimetic nanoplatforms.

Targeted Quantification of Glutathione/Arginine Redox Metabolism Based on a Novel Paired Mass Spectrometry Probe Approach for the Functional Assessment of Redox Status

Glutathione (GSH) redox control and arginine metabolism are critical in regulating the physiological response to injury and oxidative stress. Quantification assessment of the GSH/arginine redox metabolism supports monitoring metabolic pathway shifts during pathological processes and their linkages to redox regulation. However, assessing the redox status of organisms with complex matrices is challenging, and single redox molecule analysis may not be accurate for interrogating the redox status in cells and in vivo. Herein, guided by a paired derivatization strategy, we present a new ultraperformance liquid chromatography tandem mass spectrometry (UPLC-MS/MS)-based approach for the functional assessment of biological redox status. Two structurally analogous probes, 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC) and newly synthesized 2-methyl-6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (MeAQC), were set for paired derivatization. The developed approach was successfully applied to LPS-stimulated RAW 264.7 cells and HDM-induced asthma mice to obtain quantitative information on GSH/arginine redox metabolism. The results suggest that the redox status was remarkably altered upon LPS and HDM stimulation. We expect that this approach will be of good use in a clinical biomarker assay and potential drug screening associated with redox metabolism, oxidative damage, and redox signaling.

CAR-NKT Cells in Asthma: Use of NKT as a Promising Cell for CAR Therapy

NKT cells, unique lymphocytes bridging innate and adaptive immunity, offer significant potential for managing inflammatory disorders like asthma. Activating iNKT induces increasing IFN-γ, TGF-β, IL-2, and IL-10 potentially suppressing allergic asthma. However, their immunomodulatory effects, including granzyme-perforin-mediated cytotoxicity, and expression of TIM-3 and TRAIL warrant careful consideration and targeted approaches. Although CAR-T cell therapy has achieved remarkable success in treating certain cancers, its limitations necessitate exploring alternative approaches. In this context, CAR-NKT cells emerge as a promising approach for overcoming these challenges, potentially achieving safer and more effective immunotherapies. Strategies involve targeting distinct IgE-receptors and their interactions with CAR-NKT cells, potentially disrupting allergen-mast cell/basophil interactions and preventing inflammatory cytokine release. Additionally, targeting immune checkpoints like PDL-2, inducible ICOS, FASL, CTLA-4, and CD137 or dectin-1 for fungal asthma could further modulate immune responses. Furthermore, artificial intelligence and machine learning hold immense promise for revolutionizing NKT cell-based asthma therapy. AI can optimize CAR-NKT cell functionalities, design personalized treatment strategies, and unlock a future of precise and effective care. This review discusses various approaches to enhancing CAR-NKT cell efficacy and longevity, along with the challenges and opportunities they present in the treatment of allergic asthma.

Case report: Successful bronchoscopic interventional treatment of endobronchial leiomyomas

Endobronchial leiomyomas are rare benign neoplasms of the lungs that arise from the smooth muscle cells of the bronchi and bronchioles. While surgical resection is the mainstay of treatment for these tumors, bronchoscopic interventional therapies are also effective and can help preserve lung function in certain cases. A 40-year-old male patient presented with a persistent cough and sputum production for over 4 months. A chest computed tomography scan revealed nodular lesions in the lower lobe bronchus, later confirmed as an endobronchial leiomyoma. The patient refused surgical intervention and opted for minimally invasive bronchoscopic treatments, including electric snare resection, argon plasma coagulation, and balloon dilation, resulting in a successful outcome with no recurrence during follow-up. Clinicians should consider bronchoscopic interventions as a viable treatment option for endobronchial leiomyomas patients who are either ineligible for surgical resection or opt not to undergo surgery.

Role of sulfatide-reactive vNKT cells in promoting lung Treg cells via dendritic cell modulation in asthma models

Our previous studies have showed that sulfatide-reactive type II NKT (i.e. variant NKT, vNKT) cells inhibit the immunogenic maturation during the development of mature lung dendritic cells (LDCs), leading todeclined allergic airway inflammation in asthma. Nonetheless, the specific immunoregulatory roles of vNKT cells in LDC-mediated Th2 cell responses remain incompletely understood. Herein, we found that administration of sulfatide facilitated the generation of CD4+FoxP3+ regulatory T (Treg) cells in the lungs of wild-type mice, but not in CD1d-/- and Jα18-/- mice, after ovalbumin or house dust mite exposure. This finding implies that the enhancement of lung Treg cells by sulfatide requires vNKT cells, which dependent on invariant NKT (iNKT) cells. Furthermore, the CD4+FoxP3+ Treg cells induced by sulfatide-reactive vNKT cells were found to be associated with PD-L1 molecules expressed on LDCs, and this association was dependent on iNKT cells. Collectively, our findings suggest that in asthma-mimicking murine models, sulfatide-reactive vNKT cells facilitate the generation of lung Treg cells through inducing tolerogenic properties in LDCs, and this process is dependent on the presence of lung iNKT cells. These results may provide a potential therapeutic approach to treat allergic asthma.

Airway hyperresponsiveness in asthma: The role of the epithelium

Airway hyperresponsiveness (AHR) is a key clinical feature of asthma. The presence of AHR in people with asthma provides the substrate for bronchoconstriction in response to numerous diverse stimuli, contributing to airflow limitation and symptoms including breathlessness, wheeze, and chest tightness. Dysfunctional airway smooth muscle significantly contributes to AHR and is displayed as increased sensitivity to direct pharmacologic bronchoconstrictor stimuli, such as inhaled histamine and methacholine (direct AHR), or to endogenous mediators released by activated airway cells such as mast cells (indirect AHR). Research in in vivo human models has shown that the disrupted airway epithelium plays an important role in driving inflammation that mediates indirect AHR in asthma through the release of cytokines such as thymic stromal lymphopoietin and IL-33. These cytokines upregulate type 2 cytokines promoting airway eosinophilia and induce the release of bronchoconstrictor mediators from mast cells such as histamine, prostaglandin D2, and cysteinyl leukotrienes. While bronchoconstriction is largely due to airway smooth muscle contraction, airway structural changes known as remodeling, likely mediated in part by epithelial-derived mediators, also lead to airflow obstruction and may enhance AHR. In this review, we outline the current knowledge of the role of the airway epithelium in AHR in asthma and its implications on the wider disease. Increased understanding of airway epithelial biology may contribute to better treatment options, particularly in precision medicine.