BACKGROUND: Shegan-Mahuang Decoction (SMD) is a classical formula that has been used to effectively treat cold-induced asthma (CA) for 1800 years. Airway smooth muscle cells (ASMCs) play a crucial role in airway remodeling of CA and can be modulated through bitter taste-sensing type 2 receptors (TAS2Rs). Given that SMD contains numerous bitter herbs and TAS2R10 expression in ASMCs remains consistently high, it is pertinent to explore whether SMD regulates ASMCs via TAS2R10 to exert its CA mechanism.
OBJECTIVE: This study investigated the efficacy as well as the potential mechanism of SMD in CA.
METHODS: In this study, experiments in vivo were conducted using the CA rat model induced by ovalbumin (OVA) along with cold stimulation. The effects of SMD and TAS2R10 expression in CA rats were evaluated using the following methods: clinical symptoms, weights, pathological staining, immunofluorescence staining (IF), enzyme-linked immunosorbent assay (ELISA), real-time quantitative polymerase chain reaction (RT-qPCR) and western blot (WB). Assays in vitro including cell counting Kit-8 (CCK-8), ELISA, flow cytometry, TUNEL staining, RT-qPCR and WB were performed to investigate potential mechanism of SMD on the proliferation and apoptosis of ASMCs through upregulation of TAS2R10.
RESULTS: The administration of SMD resulted in a notable improvement in the symptoms, trends in weight, airway inflammation and airway remodeling observed in CA rats with upregulated TAS2R10. Mechanistically, we furtherly confirmed that SMD inhibits p70S6K/CyclinD1 pathway by upregulating TAS2R10. SMD furthermore blocked the G0/G1 phase, suppressed the proliferation and inducted apoptosis in ASMCs induced by platelet-derived growth factor-BB (PDGF-BB). Erythromycin (EM), a TAS2R10 agonist, can intensify these effects.
CONCLUSIONS: SMD significantly ameliorates CA by upregulating TAS2R10 and inhibiting the p70S6K/CyclinD1 pathway, thereby modulating ASMCs\' proliferation and apoptosis. Inspired by the Five Flavors Theory of Traditional Chinese Medicine, this study provides an updated treatment perspective for treating CA.

Asthma is a chronic pulmonary disease with the worldwide prevalence. The structural alterations of airway walls, termed as \"airway remodeling\", are documented as the core contributor to the airway dysfunction during chronic asthma. Forkhead box transcription factor FOXK2 is a critical regulator of glycolysis, a metabolic reprogramming pathway linked to pulmonary fibrosis. However, the role of FOXK2 in asthma waits further explored. In this study, the chronic asthmatic mice were induced via ovalbumin (OVA) sensitization and repetitive OVA challenge. FOXK2 was upregulated in the lungs of OVA mice and downregulated after adenovirus-mediated FOXK2 silencing. The lung inflammation, peribronchial collagen deposition, and glycolysis in OVA mice were obviously attenuated after FOXK2 knockdown. Besides, the expressions of FOXK2 and SIRT2 in human bronchial epithelial cells (BEAS-2B) were increasingly upregulated upon TGF-β1 stimulation and downregulated after FOXK2 knockdown. Moreover, the functional loss of FOXK2 remarkably suppressed TGF-β1-induced epithelial-mesenchymal transition (EMT) and glycolysis in BEAS-2B cells, as manifested by the altered expressions of EMT markers and glycolysis enzymes. The glycolysis inhibitor 2-deoxy-d-glucose (2-DG) inhibited the EMT in TGF-β1-induced cells, making glycolysis a driver of EMT. The binding of FOXK2 to SIRT2 was validated, and SIRT2 overexpression blocked the FOXK2 knockdown-mediated inhibition of EMT and glycolysis in TGF-β1-treated cells, which suggests that FOXK2 regulates EMT and glycolysis in TGF-β1-treated cells in a SIRT2-dependnet manner. Collectively, this study highlights the protective effect of FOXK2 knockdown on airway remodeling during chronic asthma.

BACKGROUND: The role of IL-13 on the airway epithelium in severe asthma leading to airway remodeling remains poorly understood.
OBJECTIVE: To study IL-13 induced airway remodeling on goblet cells and cilia in the airway epithelium in severe asthma and the impact of an anti-IL4Rα antibody, dupilumab, in vitro.
METHODS: Quantitative CT (qCT) lungs and endobronchial biopsies and brushings were obtained in 51 participants (22 severe, 11 non-severe asthma and 18 healthy participants) in the Severe Asthma Research Program (SARPIII) and measured for mucin and cilia related proteins. Epithelial cells were differentiated in air-liquid interphase (ALI) with IL-13 +/-dupilumab and assessed for mucin, cilia, cilia beat frequency (CBF) and epithelial integrity (transepithelial electrical resistance, TEER).
RESULTS: Increased Muc5AC (Δ+263.2±92.7 lums/EpiArea) and decreased ciliated cells (Δ-0.07±0.03 Foxj1+cells/EpiArea) were observed in biopsies from severe asthma when compared to healthy (p<0.01 and p=0.047 respectively). RNAseq of epithelial cell brushes confirmed a Muc5AC increase with a decrease in a 5-gene cilia-related mean in severe asthma compared to healthy (all p<0.05). IL-13 (5 ng/mL) differentiated ALI cultures of healthy and asthmatic (severe and non-severe participants) increased Muc5AC, decreased cilia (α-acytl-tubulin) in healthy (Δ+6.5±1.5%, Δ-14.1±2.7%; all p<0.001 respectively) and asthma (Δ+4.4±2.5%, Δ-13.1±2.7%; p=0.084, p<0.001 respectively); decreased epithelial integrity (TEER) in healthy (-140.9±21.3 [ohms], p<0.001) while decreasing CBF in asthma (Δ-4.4±1.7 [Hz], p<0.01). When dupilumab was added to ALI with IL-13, there was no significant decrease in Mu5AC but there was restoration of cilia in healthy and asthma participants (absolute increase of 67.5% and 32.5% cilia, all p<0.05 respectively) while CBF increased (Δ+3.6±1.1 [Hz], p<0.001) and TEER decreased (only in asthma Δ-37.8±16.2 [ohms] p<0.05).
CONCLUSIONS: IL-13 drives features of airway remodeling in severe asthma which are partially reversed by inhibiting IL-4Rα receptor in vitro.

BACKGROUND: Tocotrienols exhibit antioxidant and anti-inflammatory activities. RhoA, a small GTPase protein, plays a crucial role in regulating contractility in airway smooth muscle (ASM). Previous studies have demonstrated that γ-tocotrienols reduce ASM proliferation and migration by inhibiting the activation of RhoA. In this present study, we investigate the effect of another vitamin E isoform, β-tocotrienols, on human ASM cell proliferation and migration stimulated by platelet-derived growth factor-BB (PDGF-BB).
METHODS: Human ASM cells were pre-treated with β-tocotrienol prior to being stimulated with PDGF-BB to induce ASM cell proliferation and migration. The proliferation and migration of PDGF-BB-induced human ASM cells were assessed using colorimetric and transwell migration assays. The intracellular ROS assay kit was employed to quantify reactive oxygen species (ROS) in human ASM cells. Additionally, we explored the effect of β-tocotrienols on the signaling pathways involved in PDGF-BB-induced ASM proliferation and migration.
RESULTS: β-tocotrienol inhibited PDGF-BB-induced ASM cell proliferation and migration by reducing RhoA activation and ROS production. However, in this present study, β-tocotrienol did not affect the signaling pathways associated with cyclin D1, phosphorylated Akt1, and ERK1/2.
CONCLUSIONS: In conclusion, the inhibition of RhoA activation and ROS production by β-tocotrienol, resulting in the reduction in human ASM proliferation and migration, suggests its potential as a treatment for asthma airway remodeling.

OBJECTIVE: To explore the effects of iris xanthin on airway inflammation, airway remodeling, and the high mobility group box 1 protein (HMGB1)/Toll-like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) pathway in asthmatic young mice.
METHODS: Sixty male BALB/c young mice were randomly assigned into six groups: a blank group, a model group, a dexamethasone group, and low, medium, and high dose groups of iris xanthin, with ten mice per group. Asthma models were induced through intraperitoneal injections of a sensitizing agent [ovalbumin (OVA) 20 μg + aluminum hydroxide gel 2 mg], followed by 4% OVA aerosol inhalation. Lung function was measured using a pulmonary function tester to determine lung volume (LV), resting ventilation per minute (VE), and airway reactivity (Penh value). Hematoxylin-eosin (HE) staining was employed to examine and analyze airway remodeling. The contents of interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α) in bronchoalveolar lavage fluid were quantified using ELISA. Real-time fluorescence quantitative polymerase chain reaction and Western blot analysis were used to assess the expression of HMGB1/TLR4/NF-κB pathway-related mRNA and proteins in lung tissues.
RESULTS: Compared to the model group, the dexamethasone and iris xanthin-treated groups (low, medium, and high doses) exhibited significant increases in LV and VE (P<0.05), with incremental dose-dependent increases observed in the iris xanthin groups. Additionally, Penh values, IL-1β, IL-6, TNF-α, and airway remodeling indicators, along with mRNA levels of HMGB1, TLR4, and NF-κB p65 and protein levels of HMGB1, TLR4, and p-NF-κB p65, were all reduced (P<0.05) in a dose-dependent manner. When compared to the dexamethasone group, the low and medium dose iris xanthin groups showed decreases in LV and VE (P<0.05), whereas Penh values, IL-1β, IL-6, TNF-α, and airway remodeling indicators, along with mRNA levels of HMGB1, TLR4, NF-κB p65 and protein levels of HMGB1, TLR4, and p-NF-κB p65, were increased (P<0.05). No significant differences were noted in these indices between the high dose iris xanthin group and the dexamethasone group (P>0.05).
CONCLUSIONS: Iris xanthin can effectively alleviates airway inflammation and inhibits airway remodeling in asthmatic young mice, possibly through the suppression of the HMGB1/TLR4/NF-κB pathway.
目的: 探究鸢尾黄素对哮喘幼鼠气道炎症、气道重塑及高迁移率族蛋白B1（high mobility group box 1 protein, HMGB1）/Toll样受体4（Toll-like receptor 4, TLR4）/核因子κB（nuclear factor-κB, NF-κB）通路的影响。方法: 将60只雄性BALB/c幼鼠随机分为空白组、模型组、地塞米松组，以及鸢尾黄素低、中、高剂量组，每组10只。采用腹腔注射致敏剂［卵清蛋白（ovalbumin, OVA）20 μg+氢氧化铝凝胶2 mg］+4% OVA雾化吸入激发建立幼鼠哮喘模型。肺功能检测仪检测幼鼠肺容积（lung volume, LV）、每分钟静息通气量（resting ventilation per minute, VE）及气道反应性（Penh值）；苏木精-伊红染色观察并分析气道重塑情况；ELISA法检测肺泡灌洗液中白介素（interleukin, IL）-1β、IL-6、肿瘤坏死因子α（tumor necrosis factor alpha, TNF-α）含量；实时定量逆转录聚合酶链反应及Western blot法检测肺组织中HMGB1/TLR4/NF-κB通路相关mRNA及蛋白表达。结果: 与模型组比较，地塞米松组及鸢尾黄素低、中、高剂量组LV、VE均显著升高（P<0.05），其中鸢尾黄素各剂量组随剂量增加LV、VE升高（P<0.05）；地塞米松组及鸢尾黄素低、中、高剂量组Penh值、IL-1β、IL-6、TNF-α、气道重塑指标，以及HMGB1、TLR4、NF-κB p65 mRNA和HMGB1、TLR4、p-NF-κB p65蛋白表达水平均降低（P<0.05），其中鸢尾黄素各剂量组随剂量增加上述指标降低（P<0.05）。与地塞米松组比较，鸢尾黄素低、中剂量组LV、VE均降低（P<0.05），Penh值、IL-1β、IL-6、TNF-α、气道重塑指标，以及HMGB1、TLR4、NF-κB p65 mRNA和HMGB1、TLR4、p-NF-κB p65蛋白表达水平均升高（P<0.05）；鸢尾黄素高剂量组上述指标与地塞米松组比较差异无统计学意义（P>0.05）。结论: 鸢尾黄素能有效减轻哮喘幼鼠气道炎症，抑制气道重塑，可能与抑制HMGB1/TLR4/NF-κB通路有关。.

BACKGROUND: Equine asthma (EA) is a chronic lower airway inflammation that leads to structural and functional changes. Hyaluronic acid (HA) has crucial functions in the extracellular matrix homeostasis and inflammatory mediator activity. HA concentration in the lungs increases in several human airway diseases. However, its associations with naturally occurring EA and airway remodelling have not been previously studied. Our aim was to investigate the association of equine neutrophilic airway inflammation (NAI) severity, airway remodelling, and HA concentration in horses with naturally occurring EA. We hypothesised that HA concentration and airway remodelling would increase with the severity of NAI. HA concentrations of bronchoalveolar lavage fluid supernatant (SUP) and plasma of 27 neutrophilic EA horses, and 28 control horses were measured. Additionally, remodelling and HA staining intensity were assessed from endobronchial biopsies from 10 moderate NAI horses, 5 severe NAI horses, and 15 control horses.
RESULTS: The HA concentration in SUP was higher in EA horses compared to controls (p = 0.007). Plasma HA concentrations were not different between the groups. In the endobronchial biopsies, moderate NAI horses showed epithelial hyperplasia and inflammatory cell infiltrate, while severe NAI horses also showed fibrosis and desquamation of the epithelium. The degree of remodelling was higher in severe NAI compared to moderate NAI (p = 0.048) and controls (p = 0.016). Intense HA staining was observed in bronchial cell membranes, basement membranes, and connective tissue without significant differences between the groups.
CONCLUSIONS: The release of HA to the airway lumen increases in naturally occurring neutrophilic EA without clear changes in its tissue distribution, and significant airway remodelling only develops in severe NAI.

The efficacy of rosuvastatin in reducing allergic inflammation has been established. However, its potential to reduce airway remodeling has yet to be explored. This study aimed to evaluate the efficacy of rosuvastatin in reducing airway inflammation and remodeling in a mouse model of chronic allergic asthma induced by sensitization and challenge with OVA. Histology of the lung tissue and the number of inflammatory cells in bronchoalveolar lavage fluid (BALF) showed a marked decrease in airway inflammation and remodeling in mice treated with rosuvastatin, as evidenced by a decrease in goblet cell hyperplasia, collagen deposition, and smooth muscle hypertrophy. Furthermore, levels of inflammatory cytokines, angiogenesis-related factors, and OVA-specific IgE in BALF, plasma, and serum were all reduced upon treatment with rosuvastatin. Western blotting was employed to detect AMPK expression, while immunohistochemistry staining was used to observe the expression of remodeling signaling proteins such as α-SMA, TGF-β, MMP-9, and p-AMPKα in the lungs. It was found that the activity of 5\'-adenosine monophosphate-activated protein kinase alpha (AMPKα) was significantly lower in the lungs of OVA-induced asthmatic mice compared to Control mice. However, the administration of rosuvastatin increased the ratio of phosphorylated AMPK to total AMPKα, thus inhibiting the formation of new blood vessels, as indicated by CD31-positive staining mainly in the sub-epithelial region. These results indicate that rosuvastatin can effectively reduce airway inflammation and remodeling in mice with chronic allergic asthma caused by OVA, likely due to the reactivation of AMPKα and a decrease in angiogenesis.

Recurrent wheezing in preschool children is heterogeneous and results from numerous genetic and environmental risk factors, which result in the same final clinical manifestation of acute episodes of wheezing but have distinct underlying mechanisms. Effective disease-modifying approaches, therefore, need to target the pathways driving the symptoms. We have good evidence to show that targeting airway eosinophilia alone in early-life preschool wheezing and using inhaled corticosteroids is not disease-modifying. Although airway remodelling develops early in preschool wheezing, the challenge is identifying suitable treatments for structural airway changes. There is increasing evidence for the role of lower airway bacterial infection contributing to wheeze episodes, but clinical trials investigating the impact of targeted antibiotic treatment on disease modification are needed. There is also increasing data supporting an association between lower airway neutrophilia and wheezing in a subgroup of preschool children, but direct causation and the role of neutrophil function remain unknown. Finally, there is encouraging preliminary data for the role of inactivated mixed bacterial lysates in children with non-allergic, infection-associated wheeze episodes, but the impact on longer-term outcomes and their mechanism of action is unknown. This review outlines a range of potential novel targets and approaches that may enable secondary prevention of asthma from preschool wheezing. In parallel, the potential for harm when interventions are introduced indiscriminately is highlighted. Some of the challenges that need to be addressed, including trial designs allowing tailored interventions, the need for non-invasive biomarkers for targeted interventions, and ensuring extended and long-term follow-up after intervention, are highlighted.

BACKGROUND: The epithelial-mesenchymal transition (EMT) of human bronchial epithelial cells (HBECs) is essential for airway remodeling during asthma. Wnt5a has been implicated in various lung diseases, while its role in the EMT of HBECs during asthma is yet to be determined. This study sought to define whether Wnt5a initiated EMT, leading to airway remodeling through the induction of autophagy in HBECs.
METHODS: Microarray analysis was used to investigate the expression change of WNT5A in asthma patients. In parallel, EMT models were induced using 16HBE cells by exposing them to house dust mites (HDM) or interleukin-4 (IL-4), and then the expression of Wnt5a was observed. Using in vitro gain- and loss-of-function approaches via Wnt5a mimic peptide FOXY5 and Wnt5a inhibitor BOX5, the alterations in the expression of the epithelial marker E-cadherin and the mesenchymal marker protein were observed. Mechanistically, the Ca2+/CaMKII signaling pathway and autophagy were evaluated. An autophagy inhibitor 3-MA was used to examine Wnt5a in the regulation of autophagy during EMT. Furthermore, we used a CaMKII inhibitor KN-93 to determine whether Wnt5a induced autophagy overactivation and EMT via the Ca2+/CaMKII signaling pathway.
RESULTS: Asthma patients exhibited a significant increase in the gene expression of WNT5A compared to the healthy control. Upon HDM and IL-4 treatments, we observed that Wnt5a gene and protein expression levels were significantly increased in 16HBE cells. Interestingly, Wnt5a mimic peptide FOXY5 significantly inhibited E-cadherin and upregulated α-SMA, Collagen I, and autophagy marker proteins (Beclin1 and LC3-II). Rhodamine-phalloidin staining showed that FOXY5 resulted in a rearrangement of the cytoskeleton and an increase in the quantity of stress fibers in 16HBE cells. Importantly, blocking Wnt5a with BOX5 significantly inhibited autophagy and EMT induced by IL-4 in 16HBE cells. Mechanistically, autophagy inhibitor 3-MA and CaMKII inhibitor KN-93 reduced the EMT of 16HBE cells caused by FOXY5, as well as the increase in stress fibers, cell adhesion, and autophagy.
CONCLUSIONS: This study illustrates a new link in the Wnt5a-Ca2+/CaMKII-autophagy axis to triggering airway remodeling. Our findings may provide novel strategies for the treatment of EMT-related diseases.

Epithelial barrier damage plays a central role in the development and maintenance of allergic inflammation. Rises in the epithelial barrier permeability of airways alter tissue homeostasis and allow the penetration of allergens and other external agents. Different factors contribute to barrier impairment, such as eosinophilic infiltration and allergen protease action-eosinophilic cationic proteins\' effects and allergens\' proteolytic activity both contribute significantly to epithelial damage. In the airways, allergen proteases degrade the epithelial junctional proteins, allowing allergen penetration and its uptake by dendritic cells. This increase in allergen-immune system interaction induces the release of alarmins and the activation of type 2 inflammatory pathways, causing or worsening the main symptoms at the skin, bowel, and respiratory levels. We aim to highlight the molecular mechanisms underlying allergenic protease-induced epithelial barrier damage and the role of immune response in allergic asthma onset, maintenance, and progression. Moreover, we will explore potential clinical and radiological biomarkers of airway remodeling in allergic asthma patients.