Mouse Model Of Asthma Research Articles

CKD-497 inhibits NF-kB signaling and ameliorates inflammation and pulmonary fibrosis in ovalbumin-induced asthma and particulate matter-induced airway inflammatory diseases.

Introduction: Air pollution, allergens, and bacterial infections are major contributors to pathological respiratory disorders worldwide. CKD-497, derived from the rhizome of Atractylodes japonica and the fruits of Schisandra chinensis, is known for its ability to relieve cough and facilitate phlegm expectoration. However, its protective action against allergic asthma and fine dust-induced lung inflammation, along with its underlying mechanisms, have not been thoroughly investigated. Methods: In this study, we established mouse models of ovalbumin (OVA)-induced asthma and particulate matter (PM)-induced pulmonary inflammation to evaluate the effects of CKD-497. Mice were administered CKD-497 orally, and various parameters such as airway inflammation, mucus production, and proinflammatory cytokine levels (IL-1β, IL-6, TNF-α) were measured. Additionally, the macrophage cell line RAW264.7 was pretreated with CKD-497 and stimulated with lipopolysaccharide (LPS) to assess inflammation via the NF-kB signaling pathway. Results: Oral administration of CKD-497 effectively attenuated airway inflammation and mucus production in both OVA-induced asthma and PM-induced lung inflammation models. It also significantly decreased the production of proinflammatory cytokines IL-1β, IL-6, and TNF-α. CKD-497 alleviated leukocyte infiltration, including neutrophils, and reduced fibrillary collagen deposition in PM10-treated mice. In vitro, CKD-497 pretreatment inhibited LPS-induced inflammation in RAW264.7 cells through the suppression of the NF-kB signaling pathway. Discussion: CKD-497 shows potent anti-inflammatory effects in mouse models of asthma and PM-induced lung inflammation, potentially mediated by the inhibition of the NF-kB pathway. These findings suggest that CKD-497 could serve as a functional supplement to protect against respiratory diseases by mitigating pulmonary and airway inflammation induced by allergens and air pollution.

Cathepsin B-Activatable Bioactive Peptide Nanocarrier for High-Efficiency Immunotherapy of Asthma.

Asthma, a chronic respiratory disease closely associated with inflammation, presents ongoing treatment challenges. IALLIPF (le-Ala-Leu-Leu-Ile-Pro-Phe) is one of millet prolamins peptides (MPP) which shows anti-oxidant bioactivity by reducing the production of reactive oxygen species (ROS). Tryptophan (Trp, W) is an amino acid that has been demonstrated to possess anti-inflammatory effects. We introduce a novel cathepsin B-activatable bioactive peptides nanocarrier, PEG-IALLIPF-GFLG-W (MPP-Trp), designed for immunotherapy of asthma. MPP-Trp is synthesized, purified, and its characteristics are investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The yield of nitric oxide (NO) and pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) are examined to evaluate anti-inflammatory effects of IALLIPF, Trp and MPP-Trp. The immunomodulatory effects of IALLIPF, Trp and MPP-Trp on Th1/Th2 cell populations and cytokines are investigated by flow cytometry, qRT-PCR and ELISA assays. We explore the therapeutic effect of MPP-Trp in the mouse model of asthma by the analysis of lung histology and ELISA. It is necessary to study the biocompatibility of MPP-Trp by CCK8 assay and histopathologic analysis using hematoxylin and eosin (HE) staining. In asthmatic peripheral blood mononuclear cells (PBMCs), IALLIPF, Trp and MPP-Trp are able to significantly alleviate inflammation by inhibiting the yield of nitric oxide (NO) and pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β), especially MPP-Trp. MPP-Trp significantly upregulates Th1 cell levels while notably reducing Th2 cell levels. Furthermore, MPP-Trp effectively elevates the expression and production of interferon-gamma (IFN-γ), an essential cytokine from Th1 cells. Additionally, MPP-Trp markedly diminishes the mRNA expression and levels of key asthma pathogenesis cytokines, such as interleukin-4 (IL-4), interleukin-13 (IL-13), and interleukin-5 (IL-5), in asthma PBMCs. MPP-Trp ameliorates pulmonary pathological alterations and significantly inhibits OVA-induced inflammation in mice with asthma. It has little influence on the cell viability in Asthma-PBMCs treated with various concentrations or durations of MPP-Trp. No pathological changes, including in the heart, liver, spleen, lung, and kidney tissues, are observed in non-sensitized and non-challenged mice treated with MPP-Trp (20 mg/kg). Our research demonstrates that MPP-Trp has immunomodulatory effects on Th1/Th2 cell populations, essential in managing asthma. It considerably alleviates OVA-induced asthma by shifting the immune response towards a Th1-dominant profile, thereby reducing Th2-driven inflammation. Therefore, this novel bioactive peptide nanocarrier, MPP-Trp, holds promise as a candidate for asthma immunotherapy.

CircUQCRC2 promotes asthma progression in children by activating the VEGFA/NF-κB pathway by targeting miR-381-3p.

This study targeted to explore circUQCRC2's role and mechanism in childhood asthma. A mouse model of ovalbumin-induced asthma was established to evaluate the effects of circUQCRC2 on childhood asthma in terms of oxidative stress, inflammation, and collagen deposition. The effects of circUQCRC2 on platelet-derived growth factor-BB (PDGF-BB)-induced smooth muscle cells (SMCs) were evaluated, the downstream mRNA of miRNA and its associated pathways were predicted and validated, and their effects on asthmatic mice were evaluated. circUQCRC2 levels were upregulated in bronchoalveolar lavage fluid of asthmatic mice and PDGF-BB-treated SMCs. Depleting circUQCRC2 alleviated tissue damage in asthmatic mice, improved inflammatory levels and oxidative stress in asthmatic mice and PDGF-BB-treated SMC, inhibited malignant proliferation and migration of SMCs, and improved airway remodeling. Mechanistically, circUQCRC2 regulated VEGFA expression through miR-381-3p and activated the NF-κB cascade. circUQCRC2 knockdown inactivated the NF-κB cascade by modulating the miR-381-3p/VEGFA axis. Promoting circUQCRC2 stimulates asthma development by activating the miR-381-3p/VEGFA/NF-κB cascade. Therefore, knocking down circUQCRC2 or overexpressing miR-381-3p offers a new approach to treating childhood asthma.

Inhibition of MARCKS phosphorylation attenuates of dendritic cell migration in a murine model of acute asthma

BackgroundMARCKS (myristoylated alanine-rich C kinase substrates) serves as a substrate for protein kinase C, residing in the plasma membrane while acts as an actin filament crosslinking protein. This investigation aims to elucidate phosphorylated MARCKS (p-MARCKS) levels and activity in allergic asthma patients and explore the therapeutic potential of peptide inhibitors targeting p-MARCKS in an acute mouse model of allergic asthma. MethodsImmunohistochemistry and histology staining were employed on lung tissue slides to evaluate p-MARCKS expression and allergic asthma symptoms. Airway resistance was measured using invasive whole-body plethysmography. Flow cytometry detected lung dendritic cell migration, and migration/maturation assays were conducted on isolated murine bone marrow-derived dendritic cells (BM-DCs). ResultsElevated p-MARCKS expression was observed in both human asthmatic tissues and animal models immunized with ovalbumin or Alternaria alternata. Remarkably, asthmatic individuals showed elevated high p-MARCKS expression in lung tissues. Intraperitoneal injection of the peptide MPS, targeting the MARCKS phosphorylation site domain, before allergen challenged, effectively suppressed MARCKS phosphorylation in murine lung tissues. MPS inhibited both in vivo and in vitro migration and maturation of dendritic cells (BM-DCs) and reduced Th2-related lymphocyte activation in bronchoalveolar lavage fluid (BALF). MPS pretreatment additionally suppressed all symptoms associated with allergic airway asthma, including a reduction in inflammatory cell influx, airway mucous cell metaplasia, and airway hyperreactivity. ConclusionThese findings suggest that phosphorylated MARCKS occurs in asthmatic lung tissue, and the inhibition of MARCKS phosphorylation by the MPS peptide reduces dendritic cell migration and Th2-related lymphocytes in the lungs in a murine model of acute asthma.

The storage mite Tyrophagus putrescentiae induces greater lung inflammation than house dust mites in mice.

Exposure to storage mite (SM) and house dust mite (HDM) allergens is a risk factor for sensitization and asthma development; however, the related immune responses and their pathology have not been fully investigated. The HDMs Dermatophagoides farinae and Dermatophagoides pteronyssinus and SM Tyrophagus putrescentiae are potent allergens that induce asthma. Most SM-related studies have focused on the allergic reactions of individuals by measuring their immunoglobulin (Ig)E expression. Considering the limited research on this topic, the present study aims to investigate the differences in the immune responses induced by HDMs and SMs and histologically analyze lung tissues in a mouse asthma model to understand the differential effects of HDM and SM. The results revealed that all mite species induced airway inflammation. Mice challenged with T. putrescentiae had the highest airway resistance and total cell, eosinophil, and neutrophil counts in the bronchoalveolar lavage fluid (BALF). The SM-sensitized groups showed more severe lesions and mucus hypersecretions than the HDM-sensitized groups. Although the degree of HDM and SM exposure was the same, the damage to the respiratory lung tissue was more severe in SM-exposed mice, which resulted in excessive mucin secretion and increased fibrosis. Furthermore, these findings suggest that SM sensitization induces a more significant hypersensitivity response in mucosal immunity than HDM sensitization in asthma models.

Progesterone modulates the immune microenvironment to suppress ovalbumin-induced airway inflammation by inhibiting NETosis

Studies have demonstrated that prior to puberty, girls have a lower incidence and severity of asthma symptoms compared to boys. This study aimed to explore the role of progesterone (P4), a sex hormone, in reducing inflammation and altering the immune microenvironment in a mouse model of allergic asthma induced by OVA. Female BALB/c mice with or without ovariectomy to remove the influence of sex hormones were used for the investigations. Serum, bronchoalveolar lavage fluid (BALF), and lung tissue samples were collected for analysis. The results indicated that P4 treatment was effective in decreasing inflammation and mucus secretion in the lungs of OVA-induced allergic asthma mice. P4 treatment also reduced the influx of inflammatory cells into the BALF and increased the levels of Th1 and Th17 cytokines while decreasing the levels of Th2 and Treg cytokines in both BALF and lung microenvironment CD45+ T cells. Furthermore, P4 inhibited the infiltration of inflammatory cells into the lungs, suppressed NETosis, and reduced the number of pulmonary CD4+ T cells while increasing the number of regulatory T cells. The neutrophil elastase inhibitor GW311616A also suppressed airway inflammation and mucus production and modified the secretion of immune Th1, Th2, Th17, and Treg cytokines in lung CD45+ immune cells. These changes led to an alteration of the immunological milieu with increased Th1 and Th17 cells, accompanied by decreased Th2, Treg, and CD44+ T cells, similar to the effects of P4 treatment. Treatment with P4 inhibited NETosis by suppressing the p38 pathway activation, leading to reduced reactive oxygen species production. Moreover, P4 treatment hindered the release of double-stranded DNA during NETosis, thereby influencing the immune microenvironment in the lungs. These findings suggest that P4 treatment may be beneficial in reducing inflammation associated with allergic asthma by modulating the immune microenvironment. In conclusion, this research indicates the potential of P4 as a therapeutic agent for ameliorating inflammation in OVA-induced allergic asthma mice.

RORγt-dependent antigen-presenting cells direct regulatory T cell-mediated tolerance to food antigen.

The gastrointestinal tract is continuously exposed to foreign antigens in food and commensal microbes with potential to induce adaptive immune responses. Peripherally induced T regulatory (pTreg) cells are essential for mitigating inflammatory responses to these agents1-4. While RORγt+ antigen-presenting cells (RORγt-APCs) were shown to program gut microbiota-specific pTregs5-7, understanding of their characteristics remains incomplete, and the APC subset responsible for food tolerance has remained elusive. Here, we demonstrate that RORγt-APCs are similarly required for differentiation of food antigen-specific pTregs and establishment of oral tolerance. The ability of these cells to direct both food and microbiota-specific pTreg cell differentiation is contingent on expression of RORγt and on a unique cis-regulatory element within the Rorc gene locus (Rorc(t) +7kb). Absent this +7kb element, there was a notable increase in food antigen-specific T helper 2 (Th2) cells in lieu of pTregs, leading to compromised tolerance in a mouse asthma model. By employing single-cell analyses across these models, as well as freshly resected mesenteric lymph nodes from a human organ donor, we identified a rare subset of evolutionarily conserved APCs that are dependent on RORγt, uniquely express the Prdm16 transcription factor, and are endowed with essential mediators for inducing pTreg cell differentiation. Our findings suggest that a better understanding of how RORγt-APCs develop and how they regulate T cell responses to food and microbial antigens could offer new insights into developing therapeutic strategies for autoimmune and allergic diseases as well as organ transplant tolerance.

Novel hypoxia-induced HIF-1αactivation in asthma pathogenesis

BackgroundAsthma’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.MethodsHigh-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.ResultsA 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.ConclusionThe 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.

Gleditsiae Sinensis Fructus ingredients and mechanism in anti-asthmatic bronchitis research

BackgroundGleditsiae Sinensis Fructus (GSF) is commonly used in traditional medicine to treat respiratory diseases such as bronchial asthma. However, there is a lack of research on the chemical composition of GSF and the pharmacological substance and mechanism of action for GSF in treating bronchial asthma. PurposeThe chemical constituents of GSF were analyzed using ultrahigh-performance liquid chromatography-quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS). In this study, we combined network pharmacology, molecular docking techniques, and experimental validation to explore the therapeutic efficacy and underlying mechanism of GSF in the treatment of bronchial asthma. MethodsCharacterization of the chemical constituents of GSF was conducted using UHPLC-Q-Orbitrap HRMS. The identified chemical components were subjected to screening for active ingredients in the Swiss Absorption, Distribution, Metabolism, and Excretion (ADME) database. Relevant databases were utilized to retrieve target proteins for the active ingredients and targets associated with bronchial asthma disease, and the common targets between the two were selected. Subsequently, the protein-protein interaction (PPI) network was constructed using the String database and Cytoscape software to identify key targets. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed using the Metascape database. The "component-common target" network was constructed using Cytoscape to identify the primary active ingredients. Molecular docking validation was conducted using AutoDock software. The bronchial asthma mouse model was established using ovalbumin (OVA), and the lung organ index of the mice was measured. Lung tissue pathological changes were observed using hematoxylin and eosin (HE), Periodic Acid-Schiff (PAS), and Masson staining. The respiratory resistance (Penh) of the mice was assessed using a pulmonary function test instrument. An enzyme-linked immunosorbent assay (ELISA) was used to determine the levels of IgE, IL-4, IL-5, and IL-13 in the mouse serum. Immunofluorescence staining was performed to detect the protein expression levels of AKT and PI3K in the lung tissues. An in vitro experiment was performed to observe the effects of echinocystic acid (EA) on IL-4 stimulated Human ASMCs (hASMCs). Cell viability was measured using a CCK-8 assay to calculate the IC50 value of the EA. A wound healing test was conducted to observe the effect of EA on degree of healing. RT-qPCR was performed to detect the influence of EA on the mRNA expression levels of ALB, SRC, TNF-α, AKT1, and IL6 in the cells. ResultsA total of 95 chemical constituents were identified from the GSF. Of these, 37 were identified as active ingredients. There were 169 overlapping targets between the active ingredients and the disease targets. A topological analysis of the protein-protein interaction (PPI) network identified the core targets as IL6, TNF, ALB, AKT1, and SRC. An enrichment analysis revealed that the treatment of bronchial asthma with GSF primarily involved the AGE-RAGE signaling pathway and the PI3K-Akt signaling pathway, among others. The primary active ingredients included 13(s)-HOTRE, linolenic acid, and acacetin. The molecular docking results demonstrated a favorable binding activity between the critical components of GSF and the core targets. Animal experimental studies indicated that GSF effectively improved symptoms, lung function, and lung tissue pathological changes in the OVA-induced asthmatic mice, while alleviating inflammatory responses. GSF decreased the fluorescent intensity of the AKT and PI3K proteins. The IC50 value of EA was 30.02μg/ml. EA (30) significantly promoted the proliferation of IL4-stimulated hASMCs cells. EA (30) significantly increased the expression of ALB and SRC mRNA and decreased the expressions of TNF-α, AKT, and IL6 mRNA. ConclusionThe multiple active ingredients found in GSF exerted their anti-inflammatory effects through multiple targets and pathways. This preliminary study revealed the core target and the mechanism of action underlying its treatment of bronchial asthma. These findings provided valuable insights for further research on the pharmacological substances and quality control of GSF.

Endogenous LXR signaling controls pulmonary surfactant homeostasis and prevents lung inflammation

Lung type 2 pneumocytes (T2Ps) and alveolar macrophages (AMs) play crucial roles in the synthesis, recycling and catabolism of surfactant material, a lipid/protein fluid essential for respiratory function. The liver X receptors (LXR), LXRα and LXRβ, are transcription factors important for lipid metabolism and inflammation. While LXR activation exerts anti-inflammatory actions in lung injury caused by lipopolysaccharide (LPS) and other inflammatory stimuli, the full extent of the endogenous LXR transcriptional activity in pulmonary homeostasis is incompletely understood. Here, using mice lacking LXRα and LXRβ as experimental models, we describe how the loss of LXRs causes pulmonary lipidosis, pulmonary congestion, fibrosis and chronic inflammation due to defective de novo synthesis and recycling of surfactant material by T2Ps and defective phagocytosis and degradation of excess surfactant by AMs. LXR-deficient T2Ps display aberrant lamellar bodies and decreased expression of genes encoding for surfactant proteins and enzymes involved in cholesterol, fatty acids, and phospholipid metabolism. Moreover, LXR-deficient lungs accumulate foamy AMs with aberrant expression of cholesterol and phospholipid metabolism genes. Using a house dust mite aeroallergen-induced mouse model of asthma, we show that LXR-deficient mice exhibit a more pronounced airway reactivity to a methacholine challenge and greater pulmonary infiltration, indicating an altered physiology of LXR-deficient lungs. Moreover, pretreatment with LXR agonists ameliorated the airway reactivity in WT mice sensitized to house dust mite extracts, confirming that LXR plays an important role in lung physiology and suggesting that agonist pharmacology could be used to treat inflammatory lung diseases.Graphical

Novel Insights into Changes in Gene Expression within the Hypothalamus in Two Asthma Mouse Models: A Transcriptomic Lung-Brain Axis Study.

Patients with asthma experience elevated rates of mental illness. However, the molecular links underlying such lung-brain crosstalk remain ambiguous. Hypothalamic dysfunction is observed in many psychiatric disorders, particularly those with an inflammatory component due to many hypothalamic regions being unprotected by the blood-brain barrier. To gain a better insight into such neuropsychiatric sequelae, this study investigated gene expression differences in the hypothalamus following lung inflammation (asthma) induction in mice, using RNA transcriptome profiling. BALB/c mice were challenged with either bacterial lipopolysaccharide (LPS, E. coli) or ovalbumin (OVA) allergens or saline control (n = 7 per group), and lung inflammation was confirmed via histological examination of postmortem lung tissue. The majority of the hypothalamus was micro-dissected, and total RNA was extracted for sequencing. Differential expression analysis identified 31 statistically significant single genes (false discovery rate FDR5%) altered in expression following LPS exposure compared to controls; however, none were significantly changed following OVA treatment, suggesting a milder hypothalamic response. When gene sets were examined, 48 were upregulated and 8 were downregulated in both asthma groups relative to controls. REACTOME enrichment analysis suggests these gene sets are involved in signal transduction metabolism, immune response and neuroplasticity. Interestingly, we identified five altered gene sets directly associated with neurotransmitter signaling. Intriguingly, many of these altered gene sets can influence mental health and or/neuroinflammation in humans. These findings help characterize the links between asthma-induced lung inflammation and the brain and may assist in identifying relevant pathways and therapeutic targets for future intervention.

Monensin Suppresses Multiple Features of House Dust Mite-Induced Experimental Asthma in Mice.

Despite intense efforts to develop efficient therapeutic regimes for asthma, there is a large demand for novel treatment strategies in this disease. Here we evaluated the impact of monensin, a drug with potent anti-mast cell effects, in a mouse model of asthma. Allergic airway inflammation was induced by sensitization of mice with house dust mite (HDM) antigen, and effects of monensin on airway hyperreactivity and inflammatory parameters were studied. Following intraperitoneal administration, monensin did not suppress airway hyperreactivity but was shown to have anti-inflammatory properties, as manifested by reduced eosinophil- and lymphocyte infiltration into the airway lumen, and by suppressed inflammation of the lung tissue. After intranasal instillation, monensin exhibited similar anti-inflammatory effects as seen after intraperitoneal administration. Moreover, intranasally administered monensin was demonstrated to suppress goblet cell hyperplasia, and to cause a reduction in the expression of genes coding for key inflammatory markers. Further, monensin blocked mast cell degranulation in the airways of allergen-sensitized mice. Together, this study reveals that monensin has the capacity to suppress key pathological events associated with allergic airway inflammation.

Herbacetin Inhibits Asthma Development by Blocking the SGK1/NF-κB Signaling Pathway.

Asthma severely interferes with people's lives through coughing, wheezing and inflammation of the lungs. Herbacetin is a class of natural compounds that inhibit the development of inflammation. However, whether Herbacetin inhibits asthma has not been definitively studied. Lipopolysaccharides (LPS)-induced lung epithelial (BASE-2B) cells injury model was established, and then the relief of damaged BASE-2B cells with different concentrations of Herbacetin was examined. The cell counting kit (CCK8) was used to detect the effect of Herbacetin on the proliferation ability in ovalbumin (OVA)-induced asthma mice model, and Western Blot and flow cytometry were used to detect the effect of Herbacetin on the apoptosis in OVA-induced asthma mice model. Additionally, pulmonary pathology was detected by HE and Masson staining, and serum inflammatory factors were detected by alveolar lavage fluid. Herbacetin reduces BESA-2B cells induced by LPS level of inflammation, and reactive oxygen species (ROS) generation, inhibits cell apoptosis, promotes cell proliferation, OVA-induced mice lung histopathology test HE staining, serum inflammatory factors show the same results. Western Blot shows that Herbacetin regulates the expression of Caspase-3, Bax, and Bcl-2. SGK1 overexpression increased the rate of apoptosis, and Herbacetin reversed this phenomenon. By silencing the expression of SGK1, it was found that Herbacetin was an inhibitor of SGK1, which could inhibit the NF-κB/p-P65 pathway in asthmatic airway inflammation. Herbacetin reduces pro-inflammatory cytokine levels by inhibiting the SGK1/NF-κB pathway. Our data suggest that Herbacetin has a significant anti-inflammatory effect on asthma and can be used as a potential therapeutic agent.

LincR-PPP2R5C Deficiency Alleviates Airway Remodeling by Inhibiting Epithelial-Mesenchymal Transition Through the PP2A/TGF-β1 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)-β1, orchestrates airway remodeling. Protein phosphatase 2A (PP2A), an important serine-threonine phosphatase, is involved in TGF-β1 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-β1 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-β1 signaling pathway. Thus, lncRNAs, i.e., lincR-PPP2R5C, may be potential targets to prevent airway remodeling in allergic asthma.

Rosuvastatin attenuates airway inflammation and remodeling in a chronic allergic asthma model through modulation of the AMPKα signaling pathway.

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.

Structural basis for IL-33 recognition and its antagonism by the helminth effector protein HpARI2

IL-33 plays a significant role in inflammation, allergy, and host defence against parasitic helminths. The model gastrointestinal nematode Heligmosomoides polygyrus bakeri secretes the Alarmin Release Inhibitor HpARI2, an effector protein that suppresses protective immune responses and asthma in its host by inhibiting IL-33 signalling. Here we reveal the structure of HpARI2 bound to mouse IL-33. HpARI2 contains three CCP-like domains, and we show that it contacts IL-33 primarily through the second and third of these. A large loop which emerges from CCP3 directly contacts IL-33 and structural comparison shows that this overlaps with the binding site on IL-33 for its receptor, ST2, preventing formation of a signalling complex. Truncations of HpARI2 which lack the large loop from CCP3 are not able to block IL-33-mediated signalling in a cell-based assay and in an in vivo female mouse model of asthma. This shows that direct competition between HpARI2 and ST2 is responsible for suppression of IL-33-dependent responses.

An antibacterial, multifunctional nanogel for efficient treatment of neutrophilic asthma

Asthma is a chronic and heterogeneous disease affecting the lungs and respiratory tract. In particular, the neutrophil subtype of asthma was described as persistent, more severe, and corticosteroid-resistant. Growing evidence suggested that nontypeable Haemophilus influenzae (NTHi) infection contributes to the development of neutrophilic asthma, exacerbating clinical symptoms and increasing the associated medical burden. In this work, arginine-grafted chitosan (CS-Arg) was ionically cross-linked with tris(2-carboxyethyl) phosphine (TCEP), and a highly-efficient antimicrobial agent, poly-ε-L-Lysine (ε-PLL), was incorporated to prepare ε-PLL/CS-Arg/TCEP (ECAT) composite nanogels. The results showed that ECAT nanogels exhibited highly effective inhibition against the proliferation of NTHi, Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). In addition, ECAT nanogels could effectively inhibit the formation of mucins aggregates in vitro, suggesting that the nanogel might have the potential to destroy mucin in respiratory disease. Furthermore, in the ovalbumin (OVA)/NTHi-induced Balb/c mice model of neutrophilic asthma, the number of neutrophils in the alveolar lavage fluid and the percentage of inflammatory cells in the blood were effectively reduced by exposure to tower nebulized administration of ECAT nanogels, and reversing airway hyperresponsiveness (AHR) and reducing inflammation in neutrophilic asthma mice. In conclusion, the construction of ECAT nanogels was a feasible anti-infective and anti-inflammatory therapeutic strategy, which demonstrated strong potential in the clinical treatment of neutrophilic asthma.

Increased inhibitory surface marker PD-1 expression in CD4+T cells and Th2+T cells in allergen-specific immunotherapy

Recent evidence has shown that T cell exhaustion is implicated in Allergen-specific Immunotherapy (AIT). However, how T cell exhaustion plays a role in AIT is far from clear. Our study aimed to investigate T cell exhaustion associated with allergen exposure during AIT in mice. Ovalbumin (OVA) − sensitized C57BL/6J asthma mouse and AIT mouse models were constructed. Quantitative real-time PCR (qRTPCR) and flow cytometry were used to monitor the occurrence of local and systemic CD4+ T cells and Th2+T cells exhaustion in OVA-sensitized mice. The inhibitory surface marker programmed cell death protein 1 (PD-1) on CD4+ T cells and Th2+T cells was significantly upregulated in AIT mice compared with asthmatic and control mice. The level of PD-1 on the surface of CD4+T cells of asthma mice was significantly higher than that of control mice. The inhibitory surface marker cytotoxic T lymphocyte-associated protein 4 (CTLA-4) on CD4+ T cells and Th2+T cells showed no significant difference between the AIT, asthma and control mice. Collectively, our study indicated that the expression of PD-1 on CD4+ T cells and Th2+T cells was increased in AIT. Allergen exposure promotes the expression of PD-1 on the surface of CD4+ T cells. T cell exhaustion plays an important role in AIT.

Gasdermin D silencing alleviates airway inflammation and remodeling in an ovalbumin-induced asthmatic mouse model

Emerging evidence demonstrates that pyroptosis has been implicated in the pathogenesis of asthma. Gasdermin D (GSDMD) is the pyroptosis executioner. The mechanism of GSDMD in asthma remains unclear. The aim of this study was to elucidate the potential role of GSDMD in asthmatic airway inflammation and remodeling. Immunofluorescence staining was conducted on airway epithelial tissues obtained from both asthma patients and healthy controls (HCs) to evaluate the expression level of N-GSDMD. ELISA was used to measure concentrations of cytokines (IL-1β, IL-18, IL-17A, and IL-10) in serum samples collected from asthma patients and healthy individuals. We demonstrated that N-GSDMD, IL-18, and IL-1β were significantly increased in samples with mild asthma compared with those from the controls. Then, wild type and Gsdmd-knockout (Gsdmd−/−) mice were used to establish asthma model. We performed histopathological staining, ELISA, and flow cytometry to explore the function of GSDMD in allergic airway inflammation and tissue remodeling in vivo. We observed that the expression of N-GSDMD, IL-18, and IL-1β was enhanced in OVA-induced asthma mouse model. Gsdmd knockout resulted in attenuated IL-18, and IL-1β production in both bronchoalveolar lavage fluid (BALF) and lung tissue in asthmatic mice. In addition, Gsdmd−/− mice exhibit a significant reduction in airway inflammation and remodeling, which might be associated with reduced Th17 inflammatory response and M2 polarization of macrophages. Further, we found that GSDMD knockout may improve asthmatic airway inflammation and remodeling through regulating macrophage adhesion, migration, and macrophage M2 polarization by targeting Notch signaling pathway. These findings demonstrate that GSDMD deficiency profoundly alleviates allergic inflammation and tissue remodeling. Therefore, GSDMD may serve as a potential therapeutic target against asthma.

SCGB1C1 Plays a Critical Role in Suppression of Allergic Airway Inflammation through the Induction of Regulatory T Cell Expansion.

The nanosized vesicles secreted from various cell types into the surrounding extracellular space are called extracellular vesicles (EVs). Although mesenchymal stem cell-derived EVs are known to have immunomodulatory effects in asthmatic mice, the role of identified pulmonary genes in the suppression of allergic airway inflammation remains to be elucidated. Moreover, the major genes responsible for immune regulation in allergic airway diseases have not been well documented. This study aims to evaluate the immunomodulatory effects of secretoglobin family 1C member 1 (SCGB1C1) on asthmatic mouse models. C57BL/6 mice were sensitized to ovalbumin (OVA) using intraperitoneal injection and were intranasally challenged with OVA. To evaluate the effect of SCGB1C1 on allergic airway inflammation, 5 μg/50 μL of SCGB1C1 was administrated intranasally before an OVA challenge. We evaluated airway hyperresponsiveness (AHR), total inflammatory cells, eosinophils in the bronchoalveolar lavage fluid (BALF), lung histology, serum immunoglobulin (Ig), the cytokine profiles of BALF and lung-draining lymph nodes (LLN), and the T cell populations in LLNs. The intranasal administration of SCGB1C1 significantly inhibited AHR, the presence of eosinophils in BALF, eosinophilic inflammation, goblet cell hyperplasia in the lung, and serum total and allergen-specific IgE. SCGB1C1 treatment significantly decreased the expression of interleukin (IL)-5 in the BALF and IL-4 in the LLN, but significantly increased the expression of IL-10 and transforming growth factor (TGF)-β in the BALF. Furthermore, SCGB1C1 treatment notably increased the populations of CD4+CD25+Foxp3+ regulatory T cells (Tregs) in asthmatic mice. The intranasal administration of SCGB1C1 provides a significant reduction in allergic airway inflammation and improvement of lung function through the induction of Treg expansion. Therefore, SCGB1C1 may be the major regulator responsible for suppressing allergic airway inflammation.