Serum Galectin-10: A biomarker for persistent airflow limitation in adult asthmatics.

Background: Inhaled corticosteroids (ICS) are primary anti-inflammatory medications to control eosinophilic airway inflammation, and prevent asthma exacerbation. However, persistent airflow limitation (PAL) presents in some asthmatics even on ICS treatment, leading to lung function decline. Thus, we evaluated clinical associations of serum galectin-10 (Gal10) and galectin-3 (Gal3) levels in adult asthmatics who had maintained anti-asthma medication. Methods: Sixty-seven asthmatics and 78 healthy controls (HCs) were recruited. Serum Gal10 and Gal3 levels were measured by enzyme-linked immunosorbent assay, and their clinical relevance with inflammatory and lung function parameters was evaluated. Spirometry was performed to assess PAL and small airway dysfunction (SAD). Airway epithelial cells were cocultured with eosinophils/neutrophils, and were exposed to house dust mites to assess the production of Gal10 and Gal3. Results: Serum Gal10 (not Gal3) levels were significantly higher in asthmatics than in HCs (P < 0.001), in asthmatics with PAL than in those without PAL (P = 0.005), and in those with SAD than in those without SAD (P = 0.004). The Gal10-high group had significantly higher levels of peripheral CD66+ neutrophil counts, serum periostin and Gal3, and lower values of FEV1% and MMEF% than the Gal10-low group (P < 0.050 for all). The production of Gal10 and Gal3 was increased in eosinophilic airway model, while Gal10 (not Gal3) levels were increased in neutrophilic airway model as well as house dust mite stimulation. Conclusion: Our findings suggest that serum Gal10 level may be a potential biomarker for PAL in adult asthmatics.

Effects of liver X receptor in O3-induced airway inflammation and remodeling in mice.

Background: The current clinical treatment of chronic obstructive pulmonary disease (COPD) mainly uses drugs to improve symptoms, but these drugs cannot reverse the progression of the disease and the pathological changes in lung tissue. This study aimed to investigate the effects and mechanisms of Liver X receptors (LXRs) in ozone (O3)-induced airway inflammation and remodeling in mice. Methods: Wild mice and LXR deficient mice were exposed to O3 twice a week for 6 weeks. Some wild mice were intraperitoneally injected with T0901317 (a LXR agonist) before O3 exposure. Wild mice were exposed to ambient air and intraperitoneally injected with normal saline (NS) as control group. The lung tissues and bronchoalveolar lavage fluid (BALF) were collected to evaluate airway inflammation, airway remodeling and lipid disorder. Results: After O3 exposure, LXR deficient mice showed severe airway inflammation and airway remodeling compared with the wild mice. There were a lot of foamy macrophages appeared in BALF of LXR deficient mice. The inflammatory proteins such as myeloid differentiation primary response protein 88 (MyD88) and interleukin-1 receptor-associated kinase (IRAK) in the lung tissues of LXR deficient mice were significantly increased compared with the wild mice. In wild mice exposed to O3, T0901317 treatment can alleviate airway inflammation, airway remodeling and foamy macrophages in BALF. And MyD88 and IRAK expression in lung tissue were also attenuated by T0901317 treatment. Conclusions: LXRs play protective roles in O3-induced lipid accumulation, airway inflammation and airway remodeling.

The effects of incremental maxillomandibular advancement surgery on airway morphology: a cadaveric study.

Evidence demonstrates efficacy of maxillomandibular advancement (MMA) treatment of obstructive sleep apnea (OSA) and airway expansion. Patient studies are limited to pre/post-surgery comparisons. This cadaveric study evaluated intra-individual relationships between magnitudes of MMA advancement and airway changes. MMA with distraction osteogenesis devices and incremental advancement of the maxillomandibular complex, was performed on cadavers (n = 5). Computed tomography at each 2-mm advancement was used to measure volume and dimension of the oropharyngeal airway. Three-dimensional shape analysis visualized magnitudes and locations of changes. Incremental advancements caused volume, anteroposterior, and lateral dimensions to increase progressively, while length decreased. Changes were significant at lower advancements. Comparisons of MMA indicate alterations in airway volume from 4 to 6 mm and 6 to 8 mm were relatively greater than the changes from 8 to 10 mm (P = 0.044, P = 0.028, respectively), 10 to 12 mm (P = 0.024, P = 0.023), and 12 to 14 mm (P = 0.021, P = 0.019). These results may expand MMA application suggesting 6-8 mm advancements provide substantial increases in airway volume. MMA may be an OSA treatment option when large advancements are not possible. Lower magnitudes of advancement decrease risks of unfavorable facial esthetics from excess protrusion.

Fingolimod, a Sphingosine-1-Phosphate Receptor Modulator Prevents Neonatal Bronchopulmonary Dysplasia and subsequent Airway Remodeling in a Murine Model.

Neonatal bronchopulmonary dysplasia (BPD) is associated with alveolar simplification and airway remodeling. Airway remodeling leads to deformation of airways characterized by peribronchial collagen deposition and hypertrophy of airway smooth muscle, which contribute to the narrowing of airways. Poorly developed lungs contribute to reduced lung function that deteriorates with the passage of time. We have earlier shown that sphingosine kinase 1 (SPHK 1)/ sphingosine-1-phosphate (S1P) /S1P receptor1 (S1PR1) signaling play a role in the pathogenesis of BPD. In this study, we investigated the role of fingolimod or FTY720, a known S1PR1 modulator approved for treatment of multiple sclerosis in the treatment of BPD. Fingolimod promotes degradation of S1PR1 by preventing its recycling thus serving as the equivalent of an inhibitor. Exposure of neonatal mice to hyperoxia enhanced the expression of S1PR1 in both airways and alveoli as compared to normoxia. This increased expression of S1PR1 in the airways persisted into adulthood accompanied by airway remodeling and airway hyperreactivity (AHR) post neonatal hyperoxia. Intranasal fingolimod at a much lower dose compared to intraperitoneal route of administration during neonatal hyperoxia improved alveolarization in neonates and reduced airway remodeling and AHR in adult mice associated with improved lung function. The intranasal route was not associated with leucopenia seen with intraperitoneal route of administration of the drug. An increase in S1PR1 expression in the airways was associated with an increase in the expression of enzyme lysyl oxidase (LOX) in the airways following hyperoxia which was suppressed by fingolimod. This association warrants further investigation.

Increased luminal area of large conducting airways in patients with COVID-19 and post-acute sequelae of COVID-19: A retrospective case-control study.

Coronavirus disease 2019 (COVID-19) is associated with enlarged luminal areas of large conducting airways. In 10-30% of patients with acute COVID-19 infection, symptoms persist for more than 4 weeks (referred to as post-acute sequelae of COVID 19, or PASC), and it is unknown if airway changes are associated with this persistence. Thus, we aim to investigate if luminal area of large conducting airways is different between PASC and COVID-19 patients, and healthy controls. In this retrospective case-control study 75 patients with PASC (48 females) were age-, height-, and sex-matched to 75 individuals with COVID-19 and 75 healthy controls. Using three-dimensional digital reconstruction from computed tomography imaging, we measured luminal areas of seven conducting airways, including trachea, right and left main bronchi, bronchus intermediate, right and left upper lobe, and left lower lobe bronchi. Kruskal-Wallis H test was used to compare measurements between the three groups, as appropriate. Airway luminal areas between COVID-19 and PASC groups were not different (p>0.66). There were no group differences in airway luminal area (PASC vs. control) for trachea and right main bronchus. However, in the remaining five airways, airway luminal areas were 12% to 39% larger among PASC patients compared to controls (all, p<0.05). Patients diagnosed with COVID-19 and PASC have greater airway luminal area in most large conducting airways compared to healthy controls. No differences in luminal area between patients with COVID-19 and PASC suggest persistence of changes or insufficient time for reversal of changes.

Development and Comparative Study of a Mouse Model of Airway Inflammation and Remodeling Induced by Exosomes Derived from Bone Marrow Mesenchymal Stem Cells.

We developed a model of inflammation and airway remodeling in C57 mice provoked by exosomes derived from bone marrow mesenchymal stem cells infected by respiratory syncytial virus (RSV). The mean size of control and infected exosomes in vitro were 167.9 and 118.5 nm, respectively. After induction of modeled pathology, the severity of airway inflammation and its remodeling were analyzed by histopathological methods. In addition, the blood levels of inflammatory factors IL-10, IL-17, transforming growth factor-ß (TGF-ß), and TNFα were assayed; in the lung tissues, the expression levels of MMP-2, MMP-9, α-smooth muscle actin (α-SMA), and TGF-ß were measured. In the developed model, the effects of RSV-induced and non-induced exosomes were compared with those of inactivated and non-inactivated RSV. Intranasal administration of RSV-induced exosomes decreased the levels of serum inflammatory factors IL-10 and IL-17 and increased the expression of serum proinflammatory cytokine TNFα. Increased levels of MMP-2, MMP-9, and α-SMA, enhanced expression of TGF-ß in the lung tissue, and pathological staining of the lung tissues indicated infiltration with inflammatory cells and luminal constriction. Thus, RSV-induced exosomes can provoke airway inflammation and remodeling in mice similar to RSV, while non-induced exosomes cannot produce such alterations.

The chemical composition of secondary organic aerosols regulates transcriptomic and metabolomic signaling in an epithelial-endothelial in vitro coculture.

BACKGROUND: The formation of secondary organic aerosols (SOA) by atmospheric oxidation reactions substantially contributes to the burden of fine particulate matter (PM2.5), which has been associated with adverse health effects (e.g., cardiovascular diseases). However, the molecular and cellular effects of atmospheric aging on aerosol toxicity have not been fully elucidated, especially in model systems that enable cell-to-cell signaling. METHODS: In this study, we aimed to elucidate the complexity of atmospheric aerosol toxicology by exposing a coculture model system consisting of an alveolar (A549) and an endothelial (EA.hy926) cell line seeded in a 3D orientation at the air‒liquid interface for 4 h to model aerosols. Simulation of atmospheric aging was performed on volatile biogenic (ß-pinene) or anthropogenic (naphthalene) precursors of SOA condensing on soot particles. The similar physical properties for both SOA, but distinct differences in chemical composition (e.g., aromatic compounds, oxidation state, unsaturated carbonyls) enabled to determine specifically induced toxic effects of SOA. RESULTS: In A549 cells, exposure to naphthalene-derived SOA induced stress-related airway remodeling and an early type I immune response to a greater extent. Transcriptomic analysis of EA.hy926 cells not directly exposed to aerosol and integration with metabolome data indicated generalized systemic effects resulting from the activation of early response genes and the involvement of cardiovascular disease (CVD) -related pathways, such as the intracellular signal transduction pathway (PI3K/AKT) and pathways associated with endothelial dysfunction (iNOS; PDGF). Greater induction following anthropogenic SOA exposure might be causative for the observed secondary genotoxicity. CONCLUSION: Our findings revealed that the specific effects of SOA on directly exposed epithelial cells are highly dependent on the chemical identity, whereas non directly exposed endothelial cells exhibit more generalized systemic effects with the activation of early stress response genes and the involvement of CVD-related pathways. However, a greater correlation was made between the exposure to the anthropogenic SOA compared to the biogenic SOA. In summary, our study highlights the importance of chemical aerosol composition and the use of cell systems with cell-to-cell interplay on toxicological outcomes.

TNFSF11/TNFRSF11A Axis Amplifies HDM-Induced Airway Remodeling by Strengthening TGFß1/STAT3 Action.

PURPOSE: Asthma, an airway inflammatory disease, involves multiple tumor necrosis factors (TNF). TNF ligand superfamily member 11 (TNFSF11) and its known receptor, TNF receptor superfamily 11A (TNFRSF11A), has been implicated in asthma; however, the related mechanisms remain unknown. METHODS: The serum and bronchial airway of patients with asthma and healthy subjects were examined. The air-liquid interface of primary human bronchial epithelial (HBE) cells, and Tnfsf11+/- mouse, Tnfrsf11a+/- mouse, and a humanized HSC-NOG-EXL mouse model were established. This study constructed short hairpin RNA (shRNA) of TNFSF11, TNFRSF11A, transforming growth factor ß1 (TGFß1), and transforming growth factor ß receptor type 1 (TGFßR1) using lentivirus to further examine the ability of TNFSF11 protein. RESULTS: This study was the first to uncover TNFSF11 overexpression in the airway and serum of asthmatic human subjects, and the TNFSF11 in serum was closely correlated with lung function. The TNFSF11/TNFRSF11A axis deficiency in Tnfsf11+/- or Tnfrsf11a+/- mice remarkably attenuated the house dust mite (HDM)-induced signal transducer and activator of transcription 3 (STAT3) action and remodeling protein expression. Similarly, the HDM-induced STAT3 action and remodeling protein expression in HBE cells decreased after pretreatment with TNFSF11 or TNFRSF11A shRNA. Meanwhile, the expression of the remodeling proteins induced by TNFSF11 significantly decreased after pretreatment with-stattic (inhibitor of STAT3 phosphorylation) in HBE cells. The STAT3 phosphorylation and remodeling protein expression induced by TNFSF11 obviously decreased after pretreatment with TGFß1 or TGFßR1 shRNA in HBE cells. The above results also verified that blocking TNFSF11 with denosumab alleviated airway remodeling via the TGFß1/STAT3 signaling in the humanized HSC-NOG-EXL mice with HDM-induced asthma. CONCLUSIONS: TGFß1/STAT3 action was closely correlated with TNFSF11/TNFRSF11A axis-mediated airway remodeling. This study presented a novel strategy that blocks the TNFSF11/TNFRSF11A axis to exert a protective effect against asthma.

LincR-PPP2R5C Deficiency Alleviates Airway Remodeling by Inhibiting Epithelial-Mesenchymal Transition Through the PP2A/TGF-ß1 Signaling Pathway in Chronic Experimental Allergic Asthma.

Airway remodeling is a key characteristic of allergic asthma. Epithelial-mesenchymal transition (EMT) induced by various factors, particularly transforming growth factor (TGF)-ß1, orchestrates airway remodeling. Protein phosphatase 2A (PP2A), an important serine-threonine phosphatase, is involved in TGF-ß1 production and EMT. Long noncoding RNAs (lncRNAs) have emerged as novel players in regulating EMT. Here, we aimed to explore the effects and mechanisms of action of lincR-PPP2R5C, a lncRNA that affects PP2A activity, on airway remodeling in a mouse model of chronic allergic asthma. LincR-PPP2R5C knockout (KO) alleviated inflammatory responses in house dust mite (HDM)-induced chronic allergic asthma. Moreover, airway remodeling and EMT were reduced in lung tissues of lincR-PPP2R5C KO mice. HDM extract induced EMT in airway epithelial cells, which was decreased following lincR-PPP2R5C KO. Mechanistically, lincR-PPP2R5C deficiency enhanced PP2A activity, which inhibited TGF-ß1 production in epithelial cells. In conclusion, lincR-PPP2R5C deficiency prevented HDM-induced airway remodeling in mice by reversing EMT, which was mediated by the PP2A/TGF-ß1 signaling pathway. Thus, lncRNAs, i.e., lincR-PPP2R5C, may be potential targets to prevent airway remodeling in allergic asthma.

Mechanism of cigarette smoke in promoting small airway remodeling in mice via STAT 3 / PINK 1-Parkin / EMT.

BACKGROUND: Airway remodeling is an important pathological of airflow limitation in chronic obstructive pulmonary disease (COPD).However,its mechanism still needs to be further clarify. METHODS: Animals:Healthy male C57BL/6 mice aged 4-6 weeks were randomly divided into control group and cigarette smoke(CS)group. Mice in the CS group were placed in a homemade glass fumigator, 5 cigarettes/time, 40 min/time, 4 times/day, 5 days/week, for 24 weeks. Mice in the control group were placed in a normal air environment.Cells:BEAS-2B cells were stimulated with 0.1%cigarette smoke extract(CSE).HE staining, immunohistochemical staining and Masson staining were used to observe the pathological of lung tissues, transmission electron microscopy was used to observe the structural of mitochondria in bronchial epithelial cells.Western blotting was used to detect the expression of STAT3,transforming growth factor-ß1(TGF-ß1),microtubule-associated protein 1A/1B-light chain3(LC3),PINK1,Parkin,E-cadherin,zonula occludens1(ZO-1),vimentin and snail family transcriptional inhibitor1 (Snail1),and MitoSOX Red was used to detect mitochondrial reactive oxygen species(mtROS). RESULTS: CS exposure causes lung parenchymal destruction and airway remodeling in mice.Compared to the control group,the expression of p-STAT3,TGF-ß1 and EMT in the whole lung homogenate of the CS group was increased.Mitochondrial architecture disruption in bronchial epithelial cells of CS mice, with impaired PINK1-Parkin-dependent mitophagy.In vitro experiments showed that CSE exposure led to STAT3 activation, increased TGF-ß1,EMT and enhanced PINK1-Parkin-mediated mitophagy.STAT3 inhibition reversed TGF-ß1 upregulation induced by CSE and improved CSE-induced EMT and mitophagy.Inhibition of mitophagy improves EMT induced by CSE. Inhibition of mitophagy reduces STAT3-induced EMT. CONCLUSION: CS activates the STAT3,and activated STAT3 promotes EMT in bronchial epithelial cells by enhancing PINK1-Parkin-mediated mitophagy and TGF-ß1 signaling.Moreover, activated STAT3 can promote EMT directly.This may be one of the mechanisms by which CS causes small airway remodeling in COPD.

SMAD4 promotes EMT in COPD airway remodeling induced by cigarette smoke through interaction with O-GlcNAc transferase.

Cigarette smoke (CS) is a prevalent chemical indoor air contaminant known to be the primary cause of EMT during airway remodeling in COPD. While some evidence indicates the involvement of SMAD4 in EMT across certain diseases, its specific role in CS-induced EMT in airway remodeling associated with COPD is not established. In our research, we observed a substantial upregulation in SMAD4 expression, O-GlcNAcylation and EMT in patients with COPD, as well as in vitro and in vivo COPD models induced by CS, than those of the controls. Downregulation of SMAD4 resulted in a reduction in CS-induced EMT in vitro and in vivo. As a post-translational modification of proteins, O-GlcNAcylation is dynamically controlled by the duo of enzymes: O-linked N-acetylglucosamine (O-GlcNAc) transferase (OGT) and O-GlcNAcase (OGA). We further discovered the enhancement of O-GlcNAcylation levels induced by CS was due to an elevated OGT expression, as the expression of OGA remained unchanged. Using an OGT inhibitor (OSMI-1) counteracted the effects of SMAD4 on EMT. Whereas, overexpressing OGT increased SMAD4 expression and promoted EMT. OGT-mediated SMAD4 O-GlcNAcylation shielded SMAD4 from proteasomal degradation by reducing its ubiquitination, thereby aiding in SMAD4 stabilization in response to EMT induced by CS. Overall, this research uncovers a fresh pathway for CS-induced EMT in the airway remodeling of COPD and offers valuable insights.

G12/13 signaling in asthma.

Shortening of airway smooth muscle and bronchoconstriction are pathognomonic for asthma. Airway shortening occurs through calcium-dependent activation of myosin light chain kinase, and RhoA-dependent calcium sensitization, which inhibits myosin light chain phosphatase. The mechanism through which pro-contractile stimuli activate calcium sensitization is poorly understood. Our review of the literature suggests that pro-contractile G protein coupled receptors likely signal through G12/13 to activate RhoA and mediate calcium sensitization. This hypothesis is consistent with the effects of pro-contractile agonists on RhoA and Rho kinase activation, actin polymerization and myosin light chain phosphorylation. Recognizing the likely role of G12/13 signaling in the pathophysiology of asthma rationalizes the effects of pro-contractile stimuli on airway hyperresponsiveness, immune activation and airway remodeling, and suggests new approaches for asthma treatment.

The Role of Transforming Growth Factor-ß (TGF-ß) in Asthma and Chronic Obstructive Pulmonary Disease (COPD).

Asthma and chronic obstructive pulmonary disease (COPD) represent chronic inflammatory respiratory disorders that, despite having distinct pathophysiological underpinnings, both feature airflow obstruction and respiratory symptoms. A critical component in the pathogenesis of each condition is the transforming growth factor-ß (TGF-ß), a multifunctional cytokine that exerts varying influences across these diseases. In asthma, TGF-ß is significantly involved in airway remodeling, a key aspect marked by subepithelial fibrosis, hypertrophy of the smooth muscle, enhanced mucus production, and suppression of emphysema development. The cytokine facilitates collagen deposition and the proliferation of fibroblasts, which are crucial in the structural modifications within the airways. In contrast, the role of TGF-ß in COPD is more ambiguous. It initially acts as a protective agent, fostering tissue repair and curbing inflammation. However, prolonged exposure to environmental factors such as cigarette smoke causes TGF-ß signaling malfunction. Such dysregulation leads to abnormal tissue remodeling, marked by excessive collagen deposition, enlargement of airspaces, and, thus, accelerated development of emphysema. Additionally, TGF-ß facilitates the epithelial-to-mesenchymal transition (EMT), a process contributing to the phenotypic alterations observed in COPD. A thorough comprehension of the multifaceted role of TGF-ß in asthma and COPD is imperative for elaborating precise therapeutic interventions. We review several promising approaches that alter TGF-ß signaling. Nevertheless, additional studies are essential to delineate further the specific mechanisms of TGF-ß dysregulation and its potential therapeutic impacts in these chronic respiratory diseases.

Piezo Channels Modulate Human Lung Fibroblast Function.

Bronchial airways and lung parenchyma undergo both static and dynamic stretch in response to normal breathing but also in the context of insults such as mechanical ventilation (MV) or in diseases such as asthma and COPD which lead to airway remodeling involving increased extracellular matrix (ECM) production. Here, the role of fibroblasts is critical, but the relationship between stretch and fibroblast induced ECM remodeling under these conditions is not well-explored. Piezo (PZ) channels play a role in mechanotransduction in many cell and organ systems, but their role in mechanical stretch-induced airway remodeling is not known. To explore this, we exposed human lung fibroblasts to 10% static stretch on a background of 5% oscillations for 48 hours, with no static stretch considered controls. Collagen I, Fibronectin, α-SMA, and Piezo 1 (PZ1) expression were determined in the presence or absence of Yoda1 (PZ1 agonist) or GsMTx4 (PZ1 inhibitor). Collagen I, Fibronectin, and α-SMA expression was increased by stretch and Yoda1 while pretreatment with GsMTx4 or knockdown of PZ1 by siRNA blunted this effect. Acute stretch in the presence and absence of Yoda1 demonstrated activation of ERK pathway but not Smad. Measurement of [Ca2+] i responses to histamine showed significantly greater responses following stretch: effects that were blunted by knockdown of PZ1.Our findings identify an essential role for PZ1 in mechanical stretch-induced production of ECM mediated by ERK phosphorylation and Ca2+ influx in lung fibroblasts. Targeting PZ channels in fibroblasts may constitute a novel approach to ameliorate airway remodeling by decreasing ECM deposition.

Jolkinolide B attenuates allergic airway inflammation and airway remodeling in asthmatic mice.

Asthma is a widely prevalent chronic disease that brings great suffering to patients and may result in death if it turns severe. Jolkinolide B (JB) is one diterpenoid component separated from the dried roots of Euphorbia fischeriana Steud (Euphorbiaceae), and has anti--inflammatory, antioxidative, and antitumor properties. However, the detailed regulatory role and associated regulatory mechanism in the progression of asthma remain elusive. In this work, it was demonstrated that the extensive infiltration of bronchial inflammatory cells and the thickening of airway wall were observed in ovalbumin (OVA)-induced mice, but these impacts were reversed by JB (10 mg/kg) treatment, indicating that JB relieved the provocative symptoms in OVA-induced asthma mice. In addition, JB can control OVA-triggered lung function and pulmonary resistance. Moreover, JB attenuated OVA-evoked inflammation by lowering the levels of interleukin (IL)-4, IL-5, and IL-13. Besides, the activated nuclear factor kappa B (NF-κB) and transforming growth factor-beta-mothers against decapentaplegic homolog 3 (TGFß/smad3) pathways in OVA-induced mice are rescued by JB treatment. In conclusion, it was disclosed that JB reduced allergic airway inflammation and airway remodeling in asthmatic mice by modulating the NF-κB and TGFß/smad3 pathways. This work could offer new opinions on JB for lessening progression of asthma.

Novel hypoxia-induced HIF-1αactivation in asthma pathogenesis.

BACKGROUND: Asthma's complexity, marked by airway inflammation and remodeling, is influenced by hypoxic conditions. This study focuses on the role of Hypoxia-Inducible Factor-1 Alpha (HIF-1α) and P53 ubiquitination in asthma exacerbation. METHODS: High-throughput sequencing and bioinformatics were used to identify genes associated with asthma progression, with an emphasis on GO and KEGG pathway analyses. An asthma mouse model was developed, and airway smooth muscle cells (ASMCs) were isolated to create an in vitro hypoxia model. Cell viability, proliferation, migration, and apoptosis were assessed, along with ELISA and Hematoxylin and Eosin (H&E) staining. RESULTS: A notable increase in HIF-1α was observed in both in vivo and in vitro asthma models. HIF-1α upregulation enhanced ASMCs' viability, proliferation, and migration, while reducing apoptosis, primarily via the promotion of P53 ubiquitination through MDM2. In vivo studies showed increased inflammatory cell infiltration and airway structural changes, which were mitigated by the inhibitor IDF-11,774. CONCLUSION: The study highlights the critical role of the HIF-1α-MDM2-P53 axis in asthma, suggesting its potential as a target for therapeutic interventions. The findings indicate that modulating this pathway could offer new avenues for treating the complex respiratory disorder of asthma.

C-Phycocyanin Prevents Oxidative Stress, Inflammation, and Lung Remodeling in an Ovalbumin-Induced Rat Asthma Model.

Asthma is a chronic immunological disease related to oxidative stress and chronic inflammation; both processes promote airway remodeling with collagen deposition and matrix thickening, causing pulmonary damage and lost function. This study investigates the immunomodulation of C-phycocyanin (CPC), a natural blue pigment purified from cyanobacteria, as a potential alternative treatment to prevent the remodeling process against asthma. We conducted experiments using ovalbumin (OVA) to induce asthma in Sprague Dawley rats. Animals were divided into five groups: (1) sham + vehicle, (2) sham + CPC, (3) asthma + vehicle, (4) asthma + CPC, and (5) asthma + methylprednisolone (MP). Our findings reveal that asthma promotes hypoxemia, leukocytosis, and pulmonary myeloperoxidase (MPO) activity by increasing lipid peroxidation, reactive oxygen and nitrogen species, inflammation associated with Th2 response, and airway remodeling in the lungs. CPC and MP treatment partially prevented these physiological processes with similar action on the biomarkers evaluated. In conclusion, CPC treatment enhanced the antioxidant defense system, thereby preventing oxidative stress and reducing airway inflammation by regulating pro-inflammatory and anti-inflammatory cytokines, consequently avoiding asthma-induced airway remodeling.

FOXK2 facilitates the airway remodeling during chronic asthma by promoting glycolysis in a SIRT2-dependent manner.

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-ß1 stimulation and downregulated after FOXK2 knockdown. Moreover, the functional loss of FOXK2 remarkably suppressed TGF-ß1-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-ß1-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-ß1-treated cells, which suggests that FOXK2 regulates EMT and glycolysis in TGF-ß1-treated cells in a SIRT2-dependnet manner. Collectively, this study highlights the protective effect of FOXK2 knockdown on airway remodeling during chronic asthma.