Blockade of inflammation and airway hyperresponsiveness in immune-sensitized mice by dominant-negative phosphoinositide 3-kinase-TAT

Photobiomodulation Mitigates PM2.5-Exacerbated Pathologies in a Mouse Model of Allergic Asthma

Exposure to particulate matter (PM), especially PM2.5, is known to exacerbate asthma, posing a significant public health risk. This study investigated the asthma-reducing effects of photobiomodulation (PBM) in a mice model mimicking allergic airway inflammation exacerbated by PM2.5 exposure. The mice received sensitization with ovalbumin (OVA) and were subsequently treated with PM2.5 at a dose of 0.1 mg/kg every 3 days, for 9 times over 3 weeks during the challenge. PBM, using a 610 nm wavelength LED, was applied at 1.7 mW/cm2 to the respiratory tract via direct skin contact for 20 min daily for 19 days. Results showed that PBM significantly reduced airway hyperresponsiveness, plasma immunoglobulin E (IgE) and OVA-specific IgE, airway inflammation, T-helper type 2 cytokine, histamine and tryptase in bronchoalveolar lavage fluid (BALF), and goblet cell hyperplasia in PM2.5-exposed asthmatic mice. Moreover, PBM alleviated subepithelial fibrosis by reducing collagen deposition, airway smooth muscle mass, and expression of fibrosis-related genes. It mitigated reactive oxygen species generation, oxidative stress, endoplasmic reticulum stress, apoptotic cell death, ferroptosis, and modulated autophagic signals in the asthmatic mice exposed to PM2.5. These findings suggest that PBM could be a promising intervention for PM2.5-induced respiratory complications in patients with allergic asthma.

Lentinan attenuates allergic airway inflammation and epithelial barrier dysfunction in asthma via inhibition of the PI3K/AKT/NF-κB pathway

BACKGROUND

Allergic asthma has been regarded as an inflammatory disease mediated by type 2 immunity. The treatment of progressive forms of asthma remains unsatisfactory despite substantial progress in drug development. Lentinan (LTN), a specific polysaccharide derived from Lentinus edodes, exhibits anti-inflammatory and immunomodulatory functions. Nevertheless, the effect and underlying mechanisms of Lentinan on asthma remain unclear.

PURPOSE

This research investigated the regulatory role of Lentinan on allergic airway inflammation and epithelial barrier dysfunction in HDM (house dust mite)-induced asthma.

STUDY DESIGN

HDM-induced C57BL/6 mice received different dosages of Lentinan through intraperitoneal injections, to observe the effect of Lentinan against allergic airway inflammation and epithelial barrier dysfunction in asthma.

METHODS

Mice were intranasally administered HDM extract solution on days 0, 1, 2 and on days 8 to 12, establishing the allergic asthma model. On days 8 to 12, mice were intraperitoneally administered varying doses of Lentinan (5/10/20mg/kg) 1h before HDM challenge. On day 14, samples were harvested for analysis. Cell counting, flow cytometry, ELISA, HE and PAS staining, IF staining, western blotting, RT-PCR, and bioinformatic analysis were conducted to delve into the underlying functions and mechanisms of Lentinan in asthma.

RESULTS

Our study revealed that the treatment of Lentinan significantly ameliorated allergic airway inflammation and improved epithelial barrier dysfunction in experimental mice. Following Lentinan treatment, there was a significant reduction in eosinophil counts, accompanied by a diminished presence of type 2 cytokines. Reversal of epithelial barrier dysfunction after treatment was also observed. The therapeutic mechanism involved suppression of the PI3K/AKT/ NF-κB pathway.

CONCLUSION

Our research illuminated the protective role of Lentinan in allergic airway inflammation and impaired epithelial barrier, suggesting LTN could be an innovative and promising candidate for asthma treatment.

Revealing the regulation of allergic asthma airway epithelial cell inflammation by STEAP4 targeting MIF through machine learning algorithms and single-cell sequencing analysis

Asthma comprises one of the most common chronic inflammatory conditions, yet still lacks effective diagnostic markers and treatment targets. To gain deeper insights, we comprehensively analyzed microarray datasets of airway epithelial samples from asthmatic patients and healthy subjects in the Gene Expression Omnibus database using three machine learning algorithms. Our investigation identified a pivotal gene, STEAP4. The expression of STEAP4 in patients with allergic asthma was found to be reduced. Furthermore, it was found to negatively correlate with the severity of the disease and was subsequently validated in asthmatic mice in this study. A ROC analysis of STEAP4 showed the AUC value was greater than 0.75. Functional enrichment analysis of STEAP4 indicated a strong correlation with IL-17, steroid hormone biosynthesis, and ferroptosis signaling pathways. Subsequently, intercellular communication analysis was performed using single-cell RNA sequencing data obtained from airway epithelial cells. The results revealed that samples exhibiting low levels of STEAP4 expression had a richer MIF signaling pathway in comparison to samples with high STEAP4 expression. Through both in vitro and in vivo experiments, we further confirmed the overexpression of STEAP4 in airway epithelial cells resulted in decreased expression of MIF, which in turn caused a decrease in the levels of the cytokines IL-33, IL-25, and IL-4; In contrast, when the STEAP4 was suppressed in airway epithelial cells, there was an upregulation of MIF expression, resulting in elevated levels of the cytokines IL-33, IL-25, and IL-4. These findings suggest that STEAP4 in the airway epithelium reduces allergic asthma Th2-type inflammatory reactions by inhibiting the MIF signaling pathway.

A micropeptide TREMP encoded by lincR-PPP2R5C promotes Th2 cell differentiation by interacting with PYCR1 in allergic airway inflammation

BACKGROUND

Allergic asthma is largely dominated by Th2 lymphocytes. Micropeptides in Th2 cells and asthma remain unmasked. Here, we aimed to demonstrate a micropeptide, T-cell regulatory micropeptide (TREMP), in Th2 cell differentiation in asthma.

METHODS

TREMP translated from lincR-PPP2R5C was validated using Western blotting and mass spectrometry. TREMP knockout mice were generated using CRISPR/Cas9. Coimmunoprecipitation revealed that TREMP targeted pyrroline-5-carboxylate reductase 1 (PYCR1), which was further explored in vitro and in vivo. The levels of TREMP and PYCR1 in Th2 cells from clinical samples were determined by flow cytometry.

RESULTS

TREMP, encoded by lincR-PPP2R5C, was in the mitochondrion. The lentivirus encoding TREMP promoted Th2 cell differentiation. In contrast, Th2 differentiation was suppressed in TREMP-/- CD4+ T cells. In the HDM-induced model of allergic airway inflammation, TREMP was increased in pulmonary tissues. Allergic airway inflammation was relieved in TREMP-/- mice treated with HDM. Mechanistically, TREMP interacted with PYCR1, which regulated Th2 differentiation via glycolysis. Glycolysis was decreased in Th2 cells from TREMP-/- mice and PYCR1-/- mice. Similar to TREMP-/- mice, allergic airway inflammation was mitigated in HDM-challenged PYCR1-/- mice. Moreover, we measured TREMP and PYCR1 in asthma patients. And we found that, compared with those in healthy controls, the levels of TREMP and PYCR1 in Th2 cells were significantly increased in asthmatic patients.

CONCLUSIONS

The micropeptide TREMP encoded by lincR-PPP2R5C promoted Th2 differentiation in allergic airway inflammation by interacting with PYCR1 and enhancing glycolysis. Our findings highlight the importance of neglected micropeptides from noncoding RNAs in allergic diseases.

Recombinant Art v4.01 protein produces immunological tolerance by subcutaneous immunotherapy in a wormwood pollen-driven allergic asthma female mouse model

Art v4.01 is a well-known profilin protein belonging to the pan-allergens group and is commonly involved in triggering allergic asthma, polyallergy, and cross-sensitization. It is also referred to as Wormwood due to its origin. Crude wormwood extracts are applied for allergen-specific immunotherapy (AIT). Whether the recombinant Art v4.01 (rArt v4.01) can produce in vivo immunological tolerance by subcutaneous immunotherapy (SCIT) remains elusive. In this study, to investigate the in vivo immunological response of rArt v4.01, Th2, Th1, Treg, Th17 type-related cytokines and phenotypes of immune cells were tested, facilitating the exploration of the underlying mechanisms. The expression and purification of Art v4.01 were carried out using recombinant techniques. Allergic asthma female BALB/c mice were induced by subcutaneous sensitization of wormwood pollen extract and intranasal challenges. SCIT without adjuvant was performed using the rArt v4.01 and wormwood pollen extract for 2 weeks. Following exposure to challenges, the levels of immunoglobulin E (IgE), cytokines, and inflammatory cells were assessed through enzyme-linked immunosorbent assay (ELISA) and histological examination of sera, bronchoalveolar lavage fluid (BALF), and lung tissue. These parameters were subsequently compared between treatment groups receiving rArt v4.01 and wormwood pollen extract. The rArt v4.01 protein was expressed, which had a high purity (>90%) and an allergenic potency. Compared with the pollen extract, rArt v4.01 was superior in terms of reducing the number of white blood cells (WBCs), total nucleated cells (TNCs), and monocytes (MNs) in BALF and the degree of lung inflammation (1.77±0.99 vs. 2.31±0.80, P > 0.05). Compared with the model group, only rArt v4.01 reduced serum IgE level (1.19±0.25 vs. 1.61±0.17 μg/ml, P = 0.062), as well as the levels of Th2 type-related cytokines (interleukin-4 (IL-4) (107.18±16.17 vs. 132.47±20.85 pg/ml, P < 0.05) and IL-2 (19.52±1.19 vs. 24.02±2.14 pg/ml, P < 0.05)). The study suggested that rArt v4.01 was superior to pollen extract in reducing the number of inflammatory cells in BALF, pneumonitis, levels of pro-inflammatory cytokines, and serum IgE level. These findings confirmed that Art v4.01 could be a potential candidate protein for allergen-specific immunotherapy.

A single infusion of engineered long-lived and multifunctional T cells confers durable remission of asthma in mice

Asthma, the most prevalent respiratory disease, affects more than 300 million people and causes more than 250,000 deaths annually. Type 2-high asthma is characterized by interleukin (IL)-5-driven eosinophilia, along with airway inflammation and remodeling caused by IL-4 and IL-13. Here we utilize IL-5 as the targeting domain and deplete BCOR and ZC3H12A to engineer long-lived chimeric antigen receptor (CAR) T cells that can eradicate eosinophils. We call these cells immortal-like and functional IL-5 CAR T cells (5TIF) cells. 5TIF cells were further modified to secrete an IL-4 mutein that blocks IL-4 and IL-13 signaling, designated as 5TIF4 cells. In asthma models, a single infusion of 5TIF4 cells in fully immunocompetent mice, without any conditioning regimen, led to sustained repression of lung inflammation and alleviation of asthmatic symptoms. These data show that asthma, a common chronic disease, can be pushed into long-term remission with a single dose of long-lived CAR T cells.

Orally administered yeast-derived β-glucan alleviates mast cell-dependent airway hyperresponsiveness and inflammation in a murine model of asthma

BACKGROUND

Particulate β-glucans (WGP) are natural compounds with regulatory roles in various biological processes, including tumorigenesis and inflammatory diseases such as allergic asthma. However, their impact on mast cells (MCs), contributors to airway hyperresponsiveness (AHR) and inflammation in asthma mice, remains unknown.

METHODS

C57BL/6 mice underwent repeated OVA sensitization without alum, followed by Ovalbumin (OVA) challenge. Mice received daily oral administration of WGP (OAW) at doses of 50 or 150 mg/kg before sensitization and challenge. We assessed airway function, lung histopathology, and pulmonary inflammatory cell composition in the airways, as well as proinflammatory cytokines and chemokines in the bronchoalveolar lavage fluid (BALF).

RESULTS

The 150 mg/kg OAW treatment mitigated OVA-induced AHR and airway inflammation, evidenced by reduced airway reactivity to aerosolized methacholine (Mch), diminished inflammatory cell infiltration, and goblet cell hyperplasia in lung tissues. Additionally, OAW hindered the recruitment of inflammatory cells, including MCs and eosinophils, in lung tissues and BALF. OAW treatment attenuated proinflammatory tumor necrosis factor (TNF)-α and IL-6 levels in BALF. Notably, OAW significantly downregulated the expression of chemokines CCL3, CCL5, CCL20, CCL22, CXCL9, and CXCL10 in BALF.

CONCLUSION

These results highlight OAW's robust anti-inflammatory properties, suggesting potential benefits in treating MC-dependent AHR and allergic inflammation by influencing inflammatory cell infiltration and regulating proinflammatory cytokines and chemokines in the airways.

p53 suppresses the inflammatory response following respiratory syncytial virus infection by inhibiting TLR2

-Respiratory syncytial virus (RSV) is a pivotal virus leading to acute lower respiratory tract infections in children under 5 years old. This study aimed to explore the correlation between p53 and Toll-like receptors (TLRs) post RSV infection. p53 levels exhibited a substantial decrease in nasopharyngeal aspirates (NPAs) from infants with RSV infection compared to control group. Manipulating p53 expression had no significant impact on RSV replication or interferon signaling pathway. Suppression of p53 expression led to heightened inflammation following RSV infection in A549 cells or airways of BALB/c mice. while stabilizing p53 expression using Nutlin-3a mitigated the inflammatory response in A549 cells. Additionally, Inhibiting p53 expression significantly increased Toll-like receptor 2 (TLR2) expression in RSV-infected epithelial cells and BALB/c mice. Furthermore, the TLR2 inhibitor, C29, effectively reduced inflammation mediated by p53 in A549 cells. Collectively, our results indicate that p53 modulates the inflammatory response after RSV infection through TLR2.

Dimethyl fumarate alleviates allergic asthma by strengthening the Nrf2 signaling pathway in regulatory T cells

Allergic asthma is a widely prevalent inflammatory condition affecting people across the globe. T cells and their secretory cytokines are central to the pathogenesis of allergic asthma. Here, we have evaluated the anti-inflammatory impact of dimethyl fumarate (DMF) in allergic asthma with more focus on determining its effect on T cell responses in allergic asthma. By utilizing the ovalbumin (OVA)-induced allergic asthma model, we observed that DMF administration reduced the allergic asthma symptoms and IgE levels in the OVA-induced mice model. Histopathological analysis showed that DMF treatment in an OVA-induced animal model eased the inflammation in the nasal and bronchial tissues, with a particular decrease in the infiltration of immune cells. Additionally, RT-qPCR analysis exhibited that treatment of DMF in an OVA-induced model reduced the expression of inflammatory cytokine (IL4, IL13, and IL17) while augmenting anti-inflammatory IL10 and Foxp3 (forkhead box protein 3). Mechanistically, we found that DMF increased the expression of Foxp3 by exacerbating the expression of nuclear factor E2-related factor 2 (Nrf2), and the in-vitro activation of Foxp3+ Tregs leads to an escalated expression of Nrf2. Notably, CD4-specific Nrf2 deletion intensified the allergic asthma symptoms and reduced the in-vitro iTreg differentiation. Meanwhile, DMF failed to exert protective effects on OVA-induced allergic asthma in CD4-specific Nrf2 knock-out mice. Overall, our study illustrates that DMF enhances Nrf2 signaling in T cells to assist the differentiation of Tregs, which could improve the anti-inflammatory immune response in allergic asthma.

Radical S-adenosyl methionine domain-containing 2, a potential target of D-tryptophan in asthma treatment, regulates T helper cell type 1/2 balance

Asthma is a common chronic respiratory disease. D-tryptophan (D-TRP) can inhibit allergic airway inflammation and T helper cell type 2 (Th2) immune response. RNA-sequencing results have indicated that radical S-adenosyl methionine domain-containing 2 (RSAD2) might be a potential molecular target of D-TRP in asthma treatment. Herein, we established a mouse model of asthma using ovalbumin (OVA) via intraperitoneal injection and inhalational challenge. Gain- and loss-of-function studies of RSAD2 were performed in mice following the intratracheal delivery of lentiviral vectors (3 × 106 TU/mL). Naïve CD-4+ T cells were isolated from the spleen and used to explore the effects of RSAD2 on Th2 cell differentiation. RSAD2 expression was higher in the asthma group than in the control group. RSAD2 knockdown alleviated inflammatory cell infiltration and reduced the number of goblet cells. Low RSAD2 expression decreased the levels of IgE, IL-25, IL-33, and TSLP, and it reduced the number of inflammatory cells in the bronchoalveolar lavage fluid. RSAD2 silencing suppressed Th2-related cytokine levels (such as IL-4, IL-5, and IL-13) and increased Th1-related cytokine levels (such as IFN-γ). Additionally, RSAD2 knockdown inhibited the phosphorylation of JAK1, JAK3, and STAT6, and downregulated GATA-3 expression. RSAD2 overexpression increased inflammatory cell infiltration and mucus secretion in the lung tissues of mice pretreated with D-TRP. D-TRP pretreatment reduced OVA-specific IgE content and IL-4 and IL-5 levels, and it increased the IFN-γ levels; however, RSAD2 overexpression reversed these effects. In conclusion, RSAD2 knockdown can mitigate OVA-induced asthma by regulating the Th2 immune response via JAK/STAT6 pathway inhibition.

DNA hypomethylation-mediated upregulation of GADD45B facilitates airway inflammation and epithelial cell senescence in COPD

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease typically characterized by chronic airway inflammation, with emerging evidence highlighting the driving role of cellular senescence-related lung aging. Accelerated lung aging and inflammation mutually reinforce each other, creating a detrimental cycle that contributes to disease progression. Growth arrest and DNA damage-inducible (GADD45) family has been reported to involve in multiple biological processes, including inflammation and senescence. However, the role of GADD45 family in COPD remains elusive.

OBJECTIVES

To investigate the role and mechanism of GADD45 family in COPD pathogenesis.

METHODS

Expressions of GADD45 family were evaluated by bioinformatic analysis combined with detections in clinical specimens. The effects of GADD45B on inflammation and senescence were investigated via constructing cell model with siRNA transfection or overexpression lentivirus infection and animal model with Gadd45b knockout. Targeted bisulfite sequencing was performed to probe the influence of DNA methylation in GADD45B expression in COPD.

RESULTS

GADD45B expression was significantly increased in COPD patients and strongly associated with lung function, whereas other family members presented no changes. GADD45B upregulation was confirmed in mice exposed by cigarette smoke (CS) and HBE cells treated by CS extract as well. Moreover, experiments involving bidirectional modulation of GADD45B expression in HBE cells further substantiated its positive regulatory role in inflammatory response and cellular senescence. Mechanically, GADD45B-facilitated inflammation was directly mediated by p38 phosphorylation, while GADD45B interacted with FOS to promote cellular senescence in a p38 phosphorylation-independent manner. Furthermore, Gadd45b deficiency remarkably alleviated inflammation and senescence of lungs in CS-exposed mice, as well as improved emphysema and lung function. Eventually, in vivo and vitro experiments demonstrated that GADD45B overexpression was partially mediated by CS-induced DNA hypomethylation.

CONCLUSION

Our findings have shed light on the impact of GADD45B in the pathogenesis of COPD, thereby offering a promising target for intervention in clinical settings.

Interplay of IL-33 and IL-35 Modulates Th2/Th17 Responses in Cigarette Smoke Exposure HDM-Induced Asthma

Cigarette smoke (CS) facilitates adverse effects on the airway inflammation and treatment of asthma. Here, we investigated the mechanisms by which CS exacerbates asthma. The roles of IL-33 and IL-35 in asthma development were examined by treatment with IL-33 knockout (IL-33 KO) or transfection of adenovirus encoding IL-35 (Ad-IL-35) in a murine model of cigarette smoke-exposure asthma. Furthermore, the involvement of IL-33 and IL-35 in regulating DCs and Th2/Th17 cells was examined in a coculture system of DCs with CD4+ T cells. Additionally, we observed the effect of CpG-ODNs on the balance of IL-33 and IL-35. We show that CS and house dust mite (HDM) exposure induced IL-33 and suppressed IL-35 levels in cigarette smoke-exposure asthma in vivo and in vitro. Treatment with IL-33 KO or Ad-IL-35 significantly attenuated airway hyperreactivity, goblet hyperplasia, airway remodelling, and eosinophil and neutrophil infiltration in the lung tissues from asthmatic mice. Furthermore, we demonstrated reciprocal regulation between CS and HDM-modulated IL-33 and IL-35. Mechanistically, IL-33 KO (or anti-ST2) and Ad-IL-35 attenuated Th2- and Th17-associated inflammation by downregulating TSLP-DC signalling. Finally, administration of CpG-ODNs suppressed the expression of IL-33/ST2 and elevated the levels of IL-35, which is mainly derived from CD4+Foxp+ Tregs, to alleviate Th2- and Th17-associated inflammation by inhibiting the activation of BMDCs. Taken together, the IL-33/ST2 pathway drives the DC-Th2 and Th17 responses of cigarette smoke-exposure asthma, while IL-35 has the opposite effect. CpG-ODNs represent a potential therapeutic strategy for modulating the balance of IL-33 and IL-35 to suppress allergic airway inflammation.

Mulberroside F improves airway hyperresponsiveness and inflammation in asthmatic mice

Mulberroside F is isolated from the leaves and roots of Morus alba L. Here, we investigated whether mulberroside F could alleviate airway inflammation and eosinophil infiltration in the lungs of asthmatic mice. We also examined whether mulberroside F attenuated inflammatory responses in human tracheal epithelial BEAS-2B cells. Female BALB/c mice were sensitized and challenged with ovalbumin (OVA), and administered different doses of mulberroside F via intraperitoneal injection. Additionally, tumor necrosis factor (TNF)-α-stimulated BEAS-2B cells were treated with various doses of mulberroside F, followed by detection of the expressions of inflammatory cytokines and chemokines. The results demonstrated that mulberroside F mitigated the levels of proinflammatory cytokines and chemokines, and CCL11, in inflammatory BEAS-2B cells. Mulberroside F also suppressed reactive oxygen species (ROS) production and ICAM-1 expression in TNF-α-stimulated BEAS-2B cells, which effectively suppressed monocyte cell adherence. In an animal model of asthma, mulberroside F treatment attenuated airway hyperresponsiveness, eosinophil infiltration, and goblet cell hyperplasia. Mulberroside F treatment also decreased lung fibrosis and airway inflammation in OVA-sensitized mice. Moreover, mulberroside F significantly reduced expressions of Th2-associated cytokines (including interleukin(IL)-4, IL-5, and IL-13) in bronchoalveolar lavage fluid compared to OVA-sensitized mice. Our results confirmed that mulberroside F is a novel bioactive compound that can effectively reduce airway inflammation and eosinophil infiltration in asthmatic mice via inhibition of Th2-cell activation.

Effect of E. cava and C. indicum Complex Extract on Phorbol 12-Myristate 13-Acetate (PMA)-Stimulated Inflammatory Response in Human Pulmonary Epithelial Cells and Particulate Matter (PM)2.5-Induced Pulmonary Inflammation in Mice

This study explores the potential of a natural composite formulation known as ED, consisting of Ecklonia cava (E. cava, family: Lessoniaceae) and Chrysanthemum indicum Linne (C. indicum, family: Asteraceae), in alleviating lung inflammation induced by fine particulate matter (PM2.5). Initial assessments confirmed that neither ED nor one of its components, dieckol, exhibited cytotoxic effects on A549 cells. Subsequently, the impact of ED and dieckol on MUC5AC gene expression in A549 cells stimulated by phorbol 12-myristate 13-acetate (PMA) was investigated, revealing promising results that demonstrated a dose-dependent inhibition of MUC5AC gene expression. The study also delves into the underlying mechanisms, demonstrating that ED and dieckol effectively suppressed the phosphorylation of mitogen-activated protein kinases (MAPKs), including JNK, ERK, and p38, which are known to be involved in the regulation of MUC5AC gene expression. In in vivo experiments using a PM2.5-induced pulmonary inflammation mouse model, the research findings showed that ED mitigated cellular accumulation in the airways, leading to a significant reduction in the total cell count in bronchoalveolar lavage fluid (BALF). Moreover, ED exhibited protective effects against PM2.5-induced pulmonary damage, characterized by reduced inflammatory cell infiltration and decreased mucus secretion in pulmonary tissues. Additionally, ED's anti-inflammatory properties were evident in its ability to decrease the levels of key inflammatory cytokines, TNF-α and IL-6, both in the serum and lung tissue of the PM2.5-induced pulmonary inflammation mouse model. These findings suggest the potential of ED as a therapeutic agent for inflammatory respiratory diseases.

De novo fatty-acid synthesis protects invariant NKT cells from cell death, thereby promoting their homeostasis and pathogenic roles in airway hyperresponsiveness

Invariant natural-killer T (iNKT) cells play pathogenic roles in allergic asthma in murine models and possibly also humans. While many studies show that the development and functions of innate and adaptive immune cells depend on their metabolic state, the evidence for this in iNKT cells is very limited. It is also not clear whether such metabolic regulation of iNKT cells could participate in their pathogenic activities in asthma. Here, we showed that acetyl-coA-carboxylase 1 (ACC1)-mediated de novo fatty-acid synthesis is required for the survival of iNKT cells and their deleterious functions in allergic asthma. ACC1, which is a key fatty-acid synthesis enzyme, was highly expressed by lung iNKT cells from WT mice that were developing asthma. Cd4-Cre::Acc1fl/fl mice failed to develop OVA-induced and HDM-induced asthma. Moreover, iNKT cell-deficient mice that were reconstituted with ACC1-deficient iNKT cells failed to develop asthma, unlike when WT iNKT cells were transferred. ACC1 deficiency in iNKT cells associated with reduced expression of fatty acid-binding proteins (FABPs) and peroxisome proliferator-activated receptor (PPAR)γ, but increased glycolytic capacity that promoted iNKT-cell death. Furthermore, circulating iNKT cells from allergic-asthma patients expressed higher ACC1 and PPARG levels than the corresponding cells from non-allergic-asthma patients and healthy individuals. Thus, de novo fatty-acid synthesis prevents iNKT-cell death via an ACC1-FABP-PPARγ axis, which contributes to their homeostasis and their pathogenic roles in allergic asthma.

Lignosus rhinocerotis extract ameliorates airway inflammation and remodelling via attenuation of TGF-β1 and Activin A in a prolonged induced allergic asthma model

Allergic asthma is associated with chronic airway inflammation and progressive airway remodelling. The sclerotium of Lignosus rhinocerotis (Cooke) Ryvarden (Tiger Milk mushroom) is used traditionally to treat various illnesses, including asthma in Southeast Asia. This study was carried out to evaluate the effect of L. rhinocerotis extract (LRE) on airway inflammation and remodelling in a chronic model of asthma. The present study investigated the therapeutic effects of LRE on airway inflammation and remodelling in prolonged allergen challenged model in allergic asthma. Female Balb/C mice were sensitised using ovalbumin (OVA) on day 0 and 7, followed by OVA-challenged (3 times/week) for 2, 6 and 10 weeks. LRE (125, 250, 500 mg/kg) were administered by oral gavage one hour after every challenge. One group of mice were left untreated after the final challenge for two weeks. LRE suppressed inflammatory cells and Th2 cytokines (IL-4, IL-5 and IL-13) in BALF and reduced IgE level in the serum. LRE also attenuated eosinophils infiltration and goblet cell hyperplasia in the lung tissues; as well as ameliorated airway remodelling by reducing smooth muscle thickness and reducing the expressions of TGF-β1 and Activin A positive cell in the lung tissues. LRE attenuated airway inflammation and remodelling in the prolonged allergen challenge of allergic asthma model. These findings suggest the therapeutic potential of LRE as an alternative for the management of allergic asthma.

Exploration of the mechanism of aloin ameliorates of combined allergic rhinitis and asthma syndrome based on network pharmacology and experimental validation

Background: Aloin, as a bioactive compound, has a variety of pharmacological functions, but its effects on combined allergic rhinitis and asthma syndrome (CARAS) have not been studied. To clarify the protective effect and mechanism of aloin in the treatment of CARAS by network pharmacology, molecular dynamics simulation and experiment. Methods: The targets of aloin, allergic rhinitis and asthma were obtained from various databases. The protein interaction network was constructed for the common targets, and molecular docking and molecular dynamics simulations were performed for the core targets. Functional and pathway enrichment analysis of common targets was also performed using R software. Varieties of biological experiments were conducted to verify the effect of aloin on the inflammatory changes of CARAS and its regulatory mechanism. Results: A total of 42 anti-allergic rhinitis and 58 anti-asthma targets were obtained, and 5 core anti-allergic rhinitis and 6 core anti-asthma targets were identified using topological analysis. GO and KEGG analyses showed that endopeptidase activity and MAPK signaling pathway played important roles in allergic rhinitis and asthma. Molecular docking and molecular dynamics simulations showed that aloin could stably bind to the core target proteins. Experimental verification showed that aloin significantly inhibited the expression of inflammatory factors, and may regulate CARAS by down-regulating MAPK signaling related proteins. Conclusion: This study identified the protective effect, potential target and mechanism of aloin on CARAS. It provides reference for understanding the molecular mechanism and clinical application of aloin in the ameliorates of CARAS.

ED Formula, a Complex of Ecklonia cava and Chrysanthemum indicum, Ameliorates Airway Inflammation in Lipopolysaccharide-Stimulated RAW Macrophages and Ovalbumin-Induced Asthma Mouse Model

Ecklonia cava (E. cava) and Chrysanthemum indicum Linne (C. indicum) are natural raw materials known to have beneficial effects on inflammatory-related diseases, as evidenced by various sources in the literature. This study aimed to investigate the airway-protective effects of a formulation called ED, comprising E. cava and C. indicum, by evaluating its potential anti-inflammatory properties. Methods: The major components of ED were analyzed using high-performance liquid chromatography (HPLC) and its anti-inflammatory activity was assessed in RAW 264.7 cells through measurements of nitric oxide's (NO) inhibitory effect, cyclooxygenase (COX)-2 protein expression, and the mitogen-activated protein kinase (MAPK) signaling pathway. Additionally, the anti-inflammatory effect of ED was evaluated in an ovalbumin-induced asthma model by measuring cytokine levels in serum, bronchoalveolar lavage fluid (BALF), and lung tissue. Through HPLC analysis, the major components of ED, dieckol and luteolin, were identified. ED demonstrated no cytotoxicity and effectively reduced NO production in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Moreover, ED downregulated COX-2 expression through the MAPK signaling pathway in LPS-induced RAW 264.7 cells. In the ovalbumin-induced asthma model, the ED-treated group exhibited reduced levels of inflammatory cytokines in lung tissue. Furthermore, the ED-treated group showed a decrease in the number of inflammatory cells in BALF and lower serum interleukin (IL)-6 levels compared to the ovalbumin-treated group. These results suggest that ED has the potential to be a novel therapeutic agent for improving inflammatory respiratory diseases.

Hypermethylation of RNF125 promotes autophagy-induced oxidative stress in asthma by increasing HMGB1 stability

Asthma is a global chronic airway disease. The expression and role of RNF125, an E3 ubiquitin ligase, in asthma remain uncertain. In this study, we revealed that RNF125 was downregulated in the bronchial epithelium of mice and patients with asthma. Rnf125 hypermethylation was responsible for the low expression of RNF125 in primary airway epithelial cells of mice treated with OVA. Moreover, we demonstrated that RNF125 could attenuate autophagy, oxidative stress, and protect epithelial barrier in vivo and in vitro. Additionally, we identified HMGB1 as a substrate of RNF125, which interacted with the HMG B-box domain of HMGB1 and induced degradation via the ubiquitin proteasome system, reducing autophagy and oxidative stress. Overall, our findings elucidated that hypermethylation of Rnf125 reduced its expression, which promoted autophagy-induced oxidative stress in asthma by increasing HMGB1 stability. These findings offer a theoretical and experimental basis for the pathogenesis of asthma.

PTRF-IL33-ZBP1 signaling mediating macrophage necroptosis contributes to HDM-induced airway inflammation

Polymerase 1 and transcript release factor (PTRF, encoding by Cavin-1) regulates interleukin 33 (IL-33) release, which is implicated in asthma development. Z-DNA binding protein 1 (ZBP1)-sensing Z-RNAs induces necroptosis which causes inflammatory diseases. House dust mite (HDM) is the major source of allergen in house dust and is strongly associated with the development of asthma. Whether PTRF via IL-33 and ZBP1 mediates HDM-induced macrophage necroptosis and airway inflammation remains unclear. Here, we found that deficiency of PTRF could reduce lung IL-33, ZBP1, phosphor-receptor-interacting protein kinase 3 (p-RIPK3), and phosphor-mixed lineage kinase domain-like (p-MLKL) (necroptosis executioner), and airway inflammation in an HDM-induced asthma mouse model. In HDM-treated macrophages, ZBP1, p-RIPK3, and p-MLKL levels were markedly increased, and these changes were reversed by deletion of Cavin-1. Deletion of Il33 also reduced expression of ZBP1, p-RIPK3, and p-MLKL in HDM-challenged lungs. Moreover, IL-33 synergizing with HDM boosted expression of ZBP1, p-RIPK3, and p-MLKL in macrophages. In bronchial epithelial cells rather than macrophages and vascular endothelial cells, PTRF positively regulates IL-33 expression. Therefore, we conclude that PTRF mediates HDM-induced macrophage ZBP1/necroptosis and airway inflammation, and this effect could be boosted by bronchial epithelial cell-derived IL-33. Our findings suggest that PTRF-IL33-ZBP1 signaling pathway might be a promising target for dampening airway inflammation.

TMT-based quantitative proteomics revealed protective efficacy of Icariside II against airway inflammation and remodeling via inhibiting LAMP2, CTSD and CTSS expression in OVA-induced chronic asthma mice

BACKGROUND

Asthma is a chronic inflammatory disorder in airways with typical pathologic features of airflow limitation, airway inflammation and remodeling. Icariside II (IS), derived from herbal medicine Herba Epimedii, exerts an anti-inflammatory property. However, underlying mechanisms with specifically targeted molecular expression by IS in asthma have not been fully understood, and whether IS could inhibit remodeling and EMT still remains unclear.

PURPOSE

The study aimed to clarify therapeutic efficacy of IS for attenuating airway inflammation and remodeling in asthma, and illustrate IS-regulated specific pathway and target proteins through TMT-based quantitative proteomics.

STUDY DESIGN AND METHODS

Murine model of chronic asthma was constructed with ovalbumin (OVA) sensitization and then challenge for 8 weeks. Pulmonary function, leukocyte count in bronchoalveolar lavage fluid (BALF), lung histopathology, inflammatory and fibrotic cytokines, and markers of epithelial-mesenchymal transition (EMT) were evaluated. TMT-based quantitative proteomics were performed on lung tissues to explore IS-regulated proteins.

RESULTS

IS contributed to alleviative airway hyperresponsiveness (AHR) evidenced by declined R_L and increased Cdyn. After IS treatment, we observed a remarked down-regulation of leukocyte count, inflammatory cytokines in BALF, and peribronchial inflammation infiltration. Goblet cell hyperplasia, mucus secretion and peribronchial collagen deposition were attenuated, with the level of TGF-β and MMP-9 in BALF declined. Furthermore, IS induced a rise of Occludin and E-cadherin and a decline of N-cadherin and α-SMA in lung tissues. These results proved the protective property of IS against airway inflammation, remodeling and EMT. To further investigate underlying mechanisms of IS in asthma treatment, TMT-based quantitative proteomics were performed and 102 overlapped DEPs regulated by IS were identified. KEGG enrichment exhibited these DEPs were enriched in lysosome, phagosome and autophagy, in which LAMP2, CTSD and CTSS were common DEPs. WB, q-PCR and IHC results proofed expressional alteration of these proteins. Besides, IS could decrease Beclin-1 and LC3B expression with increasing p62 expression thus inhibiting autophagy.

CONCLUSIONS

The study demonstrated IS could ameliorate AHR, airway inflammation, remodeling and EMT in OVA-induced chronic asthma mice. Our research was the first to reveal that inhibition of LAMP2, CTSD and CTSS expression in autophagy contributed to the therapeutic efficacy of IS to asthma.

Altered intestinal microbiota in children with bronchiolitis

Objective

To investigate the correlation between the alteration of intestinal microbiota and disease in children with bronchiolitis.

Methods

Fifty seven children diagnosed with bronchiolitis from January 2020 to January 2022 in our pediatric department were included as the case group, and another 36 normal children were included as the control group. Stool and blood were collected from both groups for high-throughput sequencing, untargeted metabolite detection and ELISA. A mouse model of RSV infection was established to validate the results of clinical case detection.

Results

Body weight, passive smoking, and a host of other factors were possible as acute bronchiolitis influencing factors in the onset of acute bronchiolitis. The alpha diversity Shannon, Simpson and Pielou's evenness indices were significantly lower in children with acute bronchiolitis than in healthy children with gated levels of Firmicutes, Bacteroidetes and genus levels of Clostridium and other short chain fatty acid-producing bacteria. The relative abundance of short-chain fatty acid (SCFAs)-producing bacteria decreased and the abundance of genus-level sphingolipid-producing bacteria Sphingomonas increased; the progression of acute bronchiolitis is likely to be associated with the abundance of Clostridium and Sphingomonas and higher fecal amino acid concentrations, including FF-MAS, L-aspartic acid, thioinosinic acid, picolinic acid; supplementation with Clostridium butyricum significantly alleviated RSV infection-induced lung inflammation.

Conclusion

The progression of bronchiolitis may be associated with altered intestinal microbiota, decreased SCFAs and elevated sphingolipids metabolism in children. Some fecal bacteria and metabolites may predict the onset of bronchiolitis, and oral administration of Clostridium butyricum may alleviate RSV infection-induced pulmonary inflammation.

The Allergenic Activity of Blo t 2, a Blomia tropicalis IgE-Binding Molecule

Only few allergens derived from house dust mite (HDM) species have been evaluated in terms of their potential to induce allergic inflammation. In this study, we aimed to evaluate different aspects of the allergenicity and allergenic activity of Blo t 2, a Blomia tropicalis allergen. Blo t 2 was produced as a recombinant protein in Escherichia coli. Its allergenic activity was tested in humans by skin prick test and basophil activation assays, and in mice, by passive cutaneous anaphylaxis and a model of allergic airway inflammation. Sensitization rate to Blo t 2 (54.3%) was similar to that found to Blo t 21 (57.2%) and higher than to Der p 2 (37.5%). Most Blo t 2-sensitized patients showed a low intensity response (99.5%). Blo t 2 elicited CD203c upregulation and allergen induced skin inflammation. Additionally, immunized animals produced anti-Blo t 2 IgE antibodies and passive transfer of their serum to non-immunized animals induced skin inflammation after allergen exposure. Immunized animals developed bronchial hyperreactivity and a strong inflammatory lung reaction (eosinophils and neutrophils). These results confirm the allergenic activity of Blo t 2 and supports its clinical relevance.

Neuromedin U Induces Pulmonary ILC2 Activation via the NMUR1 Pathway during Acute Respiratory Syncytial Virus Infection

Activated group 2 innate lymphoid cells (ILC2s) play a crucial role in respiratory syncytial virus (RSV)-induced airway inflammation and allergy-like symptoms because of their ability to secrete large quantities of type 2 cytokines. Cytokines such as IL-33, IL-25, and thymic stromal lymphopoietin are activators of ILC2s. Besides, a regulatory effect of neurotransmitters on ILC2 activation has been reported recently. However, whether and how RSV infection induces neurotransmitter production in the lungs and regulates pulmonary ILC2 activation remains unclear. In this study, using a murine model established by intranasal infection with RSV, we found that acute RSV infection induced the production of a neurotransmitter, neuromedin U (NMU), in the lungs of RSV-infected mice and upregulated the expression of NMUR1 (neuromedin U receptor 1) on ILC2s. Moreover, in vivo administration of NMU exacerbated RSV-induced airway inflammation by promoting the proliferation and activation of pulmonary ILC2s via the NMUR1 pathway, which involved PI3K, mitogen-activated protein kinase kinase, and NFAT signaling proteins. Furthermore, pulmonary neurons responded to the stimulation of RSV infection and secreted NMU in a Toll-like receptor 4- and Toll-like receptor 7-dependent manner. Collectively, our data suggest that NMU is a powerful neuropeptide to activate ILC2s, highlighting the critical regulatory effects of neurotransmitters on antiviral, inflammatory, and tissue homeostasis at the mucosal barrier during a viral respiratory infection.

Fingolimod attenuates ovalbumin-induced airway inflammation via inhibiting MAPK/ERK signaling in mice

The current study was designed to investigate the potential anti-inflammatory and antioxidant effects of fingolimod against Ovalbumin (Ova)-induced allergic airway inflammation compared to dexamethasone. Fingolimod was given (0.5 mg/kg/day, p.o.) for sensitized mice 1 h before Ova challenge from Days 19 to 24. Fingolimod significantly inhibited Ova-induced elevation of inflammatory cells and eosinophils numbers in bronchoalveolar lavage fluid (BALF) and reduced concentrations of immunoglobulin E in serum and of sphingosine-1-phosphate, interleukin (IL)-4, and IL-13 in BALF. Fingolimod inhibited microvascular leakage and edema as reflected by the decreased lung/body weight index. These findings were supported by histopathological examination results showing that fingolimod substantially decreased perivascular edema and inflammatory cell infiltration. Fingolimod also attenuated Ova-induced oxidative stress as evidenced by decreased malondialdehyde concentration along with increasing concentrations of reduced glutathione and superoxide dismutase in lung tissues. Fingolimod also significantly decreased monocyte chemoattractant protein-1 (MCP-1), p-ERK, and p-P38 in lung tissues of Ova-challenged mice. In conclusion, the current study demonstrated the anti-inflammatory and antioxidant effects of fingolimod in allergic airway inflammation that might be associated with the downregulation of mitogen activated kinases signaling to decrease T helper 2 cytokine secretion (IL-4 and IL-13) and MCP-1 expression, along with the inhibition of oxidative stress.

2-Undecanone alleviates asthma by inhibiting NF-κB pathway

Asthma is characterized by airway inflammation and remodeling. 2-Undecanone (methyl nonyl ketone), a volatile organic compound originating from Houttuynia cordata, has the potential to ameliorate inflammatory diseases. This study aimed to explore potential benefits of 2-undecanone in asthma. 2-Undecanone (100, 200, or 400 mg/kg) was administered intragastrically to ovalbumin (OVA)-challenged BALB/c mice. Lung tissues were collected to observe histopathological changes, and bronchoalveolar lavage fluid (BALF) was collected for the detection of inflammatory cells and cytokine production. The results showed that 2-undecanone ameliorated OVA-induced pathologic changes of lungs, including reducing inflammatory cell infiltration, goblet cell hyperplasia, and airway smooth muscle thickness. The number of inflammatory cells and the levels of IL-4, IL-5, IL-13, and IgE in BALF were decreased by 2-undecanone in asthmatic mice. Furthermore, abnormal activation of NF-κB pathway in lung tissues of asthmatic mice was impeded by 2-undecanone. In vitro, 2-undecanone (12.5, 25, or 50 µM) suppressed platelet-derived growth factor-BB-induced proliferation and migration of primary airway smooth muscle cells (ASMCs), and inhibited the switching of ASMCs from contractile phenotype to synthetic phenotype. Consistently, 2-undecanone blocked NF-κB activation in ASMCs. Collectively, 2-undecanone relieves asthma through alleviating airway inflammation and remodeling, and this beneficial effect is achieved by inhibiting NF-κB pathway.

Regulation of ferroptosis and ACSL4-15LO1 pathway contributed to the anti-asthma effect of acupuncture

Acupuncture has been frequently used in China for the treatment asthma for thousands of years. Ferroptosis was recently revealed to be involved in several pathological conditions including asthma. However, the detailed links between ferroptosis and airway inflammation in asthma, as well as the detailed regulation of acupuncture on these disorders remains unclear. Our results demonstrated that the non-haem Fe²⁺ level increased markedly in the lung tissue of mouse asthma model, and positively correlated with R_L and IL-4 level in BALF. Furthermore, lipid peroxidation markers MDA and GSSG increased remarkably in OVA-induced experimental asthma mice. Up-regulation of lipid peroxidation associated proteins ACSL4 and15-LO1 was also observed in OVA-induced experimental asthma mice. To demonstrate the role of ferroptosis in asthma and the effect of acupuncture on these disorders, ferroptosis-induction agent erastin and ferroptosis-inhibition agent fer-1 were used, and our data demonstrated that erastin could augment lung inflammation and lipid peroxidation in OVA induced asthma model. Fer-1 was able to relieve AHR, lung inflammation, non-haem Fe²⁺ level, lipid peroxidation and ferroptosis related pathway ACSL4-15LO1 in OVA-induced experimental asthma mice. Acupuncture treatment alleviated R_L, lung inflammation as well as type 2 cytokines IL-4 and IL-13 levels induced by OVA inhalation. What's more, acupuncture significantly reduced the MDA and GSSG levels, the non-haem Fe²⁺ level and ACSL4-15-LO1 proteins expression. Acupuncture also relieved erastin-induced exacerbation in lung inflammation and lipid peroxidation in ferroptosis. Acupuncture treatment could relieve ferroptosis related exacerbation in airway inflammation. Our study provided insights into the underlying mechanisms for the protective effects of acupuncture and highlighted a therapeutic potential of acupuncture treatment in the attenuation of lipid peroxidation and ferroptosis in asthma.

Collagen Triple Helix Repeat Containing 1 Deficiency Protects Against Airway Remodeling and Inflammation in Asthma Models In Vivo and In Vitro

Asthma is a chronic inflammatory disease characterized by airway remodeling and lung inflammation. Collagen triple helix repeat containing 1 (CTHRC1), a glycoprotein, is involved in multiple pathological processes, including inflammation and fibrosis. However, the function of CTHRC1 in asthma remains unclear. In the present study, the mouse asthma model was successfully generated by sensitizing and challenging mice with ovalbumin (OVA). CTHRC1 expression at both RNA and protein levels was significantly upregulated in lung tissues of asthmatic mice. Asthmatic mice exhibited significant airway remodeling as evidenced by increased bronchial wall and smooth muscle cell layer thickness, goblet cell hyperplasia and collagen deposition, and epithelial-mesenchymal transition (EMT), but those characteristics were reversed by CTHRC1 silencing. The cell model with transforming growth factor-β1 (TGF-β1) induction in bronchial epithelial cells (BEAS-2B) was conducted to verify the effects of CTHRC1 on EMT, a classic mechanism that mediates airway remodeling. The results showed that TGF-β1 stimulation increased CTHRC1 expression, and CTHRC1 knockdown inhibited TGF-β1-induced EMT. OVA-treated mice also showed increased inflammatory cell infiltration and the production of OVA-specific immunoglobulin E (IgE), interleukin (IL)-4, IL-5, and IL-13, which were decreased by CTHRC1 downregulation. The effects of CTHRC1 on OVA-induced airway inflammation were further determined by treating BEAS-2B cells with IL-13, in which CTHRC1 knockdown reduced the IL-13-induced secretion of pro-inflammatory factors, including IL-4 and IL-5. In conclusion, these results indicate that CTHRC1 silencing attenuates asthmatic airway remodeling and inflammation in vivo and in vitro, suggesting that CTHRC1 may be a potential target for asthma treatment.

Multi-omics reveals the mechanisms of DEHP driven pulmonary toxicity in ovalbumin-sensitized mice

The plasticizer di- (2-ethylhexyl) phthalate (DEHP) is considered a risk factor for allergic diseases and has attracted public attention for its adverse effects on health. However, respiratory adverse effects after DEHP exposure in food allergies have rarely been reported. MiRNAs are considered to be key regulators in the complex interrelationships between the host and microbiome and may be a potential factor involved in DEHP-induced pulmonary toxicity. To investigate the adverse effects of DEHP on the lung during sensitization, we established an ovalbumin (OVA)-sensitized mouse model exposed to DEHP and performed 16S rDNA gene sequencing, miRNA sequencing, and correlation analysis. Our results showed that DEHP aggravated the immune disorder in OVA-sensitized mice, which was mainly characterized by an increase in the proportion of Th2 lymphocytes, and further enhanced OVA-induced airway inflammation without promoting pulmonary fibrosis. Compared with the OVA group, DEHP interfered with the lung microbial community, making Proteobacteria the dominant phylum, while Bacteroidetes were significantly reduced. Differentially expressed miRNAs were enriched in the PI3K/AKT pathway, which was closely related to immune function and airway inflammation. The expression of miR-146b-5p was elevated in the DEHP group, which was positively correlated with the proportion of Th2 cells and significantly negatively correlated with the abundance of Bacteroidetes. The results indicate that DEHP may interfere with the expression of miR-146b-5p, affect the composition of the lung microbiota, induce an imbalance in T cells, and lead to immune disorders and airway inflammation. The current study uses multi-omics to reveal the potential link between the plasticizer DEHP and allergic diseases and provides new insights into the ecotoxicology of environmental exposures to DEHP.

C-Fiber Degeneration Enhances Alveolar Macrophage-Mediated IFN-α/β Response to Respiratory Syncytial Virus

Stimulation of unmyelinated C fibers, the nociceptive sensory nerves, by noxious stimuli is able to initiate host responses. Host defensive responses against respiratory syncytial virus (RSV) infection rely on the induction of a robust alpha/beta interferon (IFN-α/β) response, which acts to restrict viral production and promote antiviral immune responses. Alveolar macrophages (AMs) are the major source of IFN-α/β upon RSV infection. Here, we found that C fibers are involved in host defense against RSV infection. Compared to the control mice post-RSV infection, degeneration and inhibition of C fibers by blockade of transient receptor potential vanilloid 1 (TRPV1) lowered viral replication and alleviated lung inflammation. Importantly, AMs were markedly elevated in C-fiber-degenerated (KCF) mice post-RSV infection, which was associated with higher IFN-α/β secretion as measured in bronchoalveolar lavage fluid (BALF) samples. Degeneration of C fibers contributed to the production of vasoactive intestinal peptide (VIP), which modulated AM and IFN-α/β levels to protect against RSV infection. Collectively, these findings revealed the key role of C fibers in regulating AM and IFN-α/β responses against RSV infection via VIP, opening the possibility for new therapeutic strategies against RSV. IMPORTANCE Despite continuous advances in medicine, safe and effective drugs against RSV infection remain elusive. As such, host-RSV interactions and host-directed therapies require further research. Unmyelinated C fibers, the nociceptive sensory nerves, play an important role in regulating the host response to virus. In the present study, from the perspective of neuroimmune interactions, we clarified that C-fiber degeneration enhanced the AM-mediated IFN-α/β response against RSV via VIP, providing potential therapeutic targets for the treatment of RSV infection.

Role of IL-22 in acute asthma mouse model

Introduction: Allergic asthma is often associated with eosinophilic inflammation, which is related to the T-helper cell type 2 (Th2) cytokines and responsive to corticosteroids. However, there are also phenotypes of non-Th2-mediated asthma, which have poor responsivity to corticosteroids. The leading phenotype of non-Th2-mediated asthma is neutrophilic asthma, which is considered difficult to treat. Recently, IL-22 has been found to be involved in neutrophilic inflammation in asthma. However, studies on the role of IL-22 in asthma are still controversial as IL-22 has both pro-inflammatory and anti-inflammatory roles in asthma. This study examined whether the IL-22 level increased in acute neutrophilic asthma in the mouse model. Herein, we aimed to demonstrate increased IL-22 levels in neutrophilic asthma and elucidate the pathways leading to elevated neutrophil counts.Methods: Six-week old female BALB/c mice were sensitized and challenged with PBS, ovalbumin (OVA) or OVA + lipopolysaccharide (LPS). The mice were then assigned to one of the following five groups: (1) control (PBS/ PBS), (2) OVA/PBS, (3) OVA/OVA, (4) OVA+LPS/PBS, (5) OVA+LPS/OVA+LPS.Results: The levels of Th2 cytokines, IL-17, and IL-22 were assessed, with investigation of the neutrophil chemokines. This study showed that in the acute neutrophilic asthma, the levels of IL-17 and IL-22 were significantly higher than those in the OVA/OVA group, which represents acute eosinophilic asthma. Moreover, the level of CCL20 increased in the neutrophilic asthma group.Conclusion: Thus, this study suggests that in the acute neutrophilic asthma mouse model, IL-17 and IL-22 may increase with CCL20, resulting in neutrophilic inflammation.

Nrf2 regulates downstream genes by targeting miR-29b in severe asthma and the role of grape seed proanthocyanidin extract in a murine model of steroid-insensitive asthma

CONTEXT

Grape seed proanthocyanidin extract (GSPE) is effective in treating severe asthma (SA).

OBJECTIVE

To examine the relationship between Nrf2-miR-29b axis and SA, and to detect whether preventive use of GSPE relieves SA via it.

MATERIALS AND METHODS

We recruited 10 healthy controls, 10 patients with non-severe asthma (nSA), and 9 patients with SA from February 2017 to December 2017. Peripheral blood mononuclear cells from these volunteers were extracted. A murine model of steroid-insensitive asthma was established in six-week-old female BALB/c mice that were sensitised and challenged with OVA, Al(OH)₃ and LPS for 31 days. Mice in the treated groups were injected with DXM (5 mg/kg/d), with or without GSPE (100 mg/kg/d). Control group received PBS. We performed quantitative real-time PCR, western blot and luciferase reporter assay in animal and cell models.

RESULTS

SA group demonstrated significantly lower concentrations of Nrf2 protein, Nrf2 mRNA, and miR-29b than nSA group and control group. Conversely, higher levels of platelet derived growth factor C (PDGFC), phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1), and collagen type III alpha 1 (COL3A1) were measured in SA than in the other two groups. PDGFC, PIK3R1, and COL3A1 were the target genes of miR-29b. GSPE + DXM significantly elevated the expression of Nrf2 (+188%), Nrf2 mRNA (+506%), and miR-29b (+201%), and significantly reduced the expression of PDGFC (-72%), PIK3R1 (-40%), and COL3A1 (-65%) compared with OVA + LPS.

CONCLUSIONS

Nrf2-miR-29b axis is involved in the pathogenesis of SA. GSPE, as an adjuvant drug, maybe a potential therapeutic agent for SA.

NOD2 Signaling Circuitry during Allergen Sensitization Does Not Worsen Experimental Neutrophilic Asthma but Promotes a Th2/Th17 Profile in Asthma Patients but Not Healthy Subjects

Nucleotide-binding oligomerization domain 2 (NOD2) recognizes pathogens associated with the development of asthma. Moreover, NOD2 adjuvants are used in vaccine design to boost immune responses. Muramyl di-peptide (MDP) is a NOD2 ligand, which is able to promote Th2/Th17 responses. Furthermore, polymorphisms of the NOD2 receptor are associated with allergy and asthma development. This study aimed to evaluate if MDP given as an adjuvant during allergen sensitization may worsen the development of Th2/Th17 responses. We used a mouse model of Th2/Th17-type allergic neutrophil airway inflammation (AAI) to dog allergen, with in vitro polarization of human naive T cells by dendritic cells (DC) from healthy and dog-allergic asthma subjects. In the mouse model, intranasal co-administration of MDP did not modify the AAI parameters, including Th2/Th17-type lung inflammation. In humans, MDP co-stimulation of allergen-primed DC did not change the polarization profile of T cells in healthy subjects but elicited a Th2/Th17 profile in asthma subjects, as compared with MDP alone. These results support the idea that NOD2 may not be involved in the infection-related development of asthma and that, while care has to be taken in asthma patients, NOD2 adjuvants might be used in non-sensitized individuals.

Liproxstatin-1 alleviates LPS/IL-13-induced bronchial epithelial cell injury and neutrophilic asthma in mice by inhibiting ferroptosis

BACKGROUND AND PURPOSE

Ferroptosis is closely associated with respiratory diseases; however, the relationship between ferroptosis and neutrophilic asthma remains unknown. This study investigated whether Liproxstatin-1 (Lip-1) affects the progression of neutrophilic asthma by inhibiting ferroptosis and inflammatory response, while dissecting the underlying molecular mechanisms.

METHODS

The bronchial epithelial cells (16HBE and BEAS-2B) were administered with lipopolysaccharide (LPS) and interleukin-13 (IL-13) to generate a cell injury model. This cell model was employed to examine the effect of Lip-1 on airway epithelial-associated inflammation and ferroptosis as well as the underlying molecular mechanism. Meanwhile, we evaluated the effects of Lip-1 on neutrophilic asthma and ferroptosis by using the ovalbumin (OVA)/LPS-induced mouse model.

RESULTS

Lip-1 reversed the altered expression of ferroptotic regulators (glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11) and prostaglandin-endoperoxide synthase 2 (PTGS2)), attenuated lipid reactive oxygen species (lipid ROS) and ameliorated cell viability in HBE and BEAS-2B cells administered with LPS and IL-13. Moreover, Lip-1 treatment led to a marked reduction in the expression of IL-33, TSLP, IL-8, IL-6, and HMGB1 in the HBE and BEAS-2B cells. In the meantime, administration with Lip-1 markedly relieved OVA/LPS-induced neutrophilic asthma, as indicated by significant improvement in lung pathological changes, airway mucus secretion, inflammation, and ferroptosis.

CONCLUSION

This study provides data suggesting that Lip-1 alleviates neutrophilic asthma in vivo and in vitro through inhibiting ferroptosis, perhaps providing a new strategy for neutrophilic asthma treatment.

Blockade of NLRP3/Caspase-1/IL-1β Regulated Th17/Treg Immune Imbalance and Attenuated the Neutrophilic Airway Inflammation in an Ovalbumin-Induced Murine Model of Asthma

Asthma is a heterogeneous inflammatory disorder of the airways, and multiple studies have addressed the vital role of the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3 (NLRP3)/caspase-1/interleukin-1β (IL-1β) pathway in asthma, but its impact on ovalbumin- (OVA-) induced neutrophilic asthma remains unclear. Here, we explored this pathway's effect on airway inflammation in neutrophilic asthma to clarify whether blocking this signaling could alleviate asthmatic airway inflammation. Using an established OVA-induced neutrophilic asthma mouse model, we provided asthmatic mice with a highly selective NLRP3 inhibitor, MCC950, and a specific caspase-1 inhibitor, Ac-YVAD-cmk. Our results indicated that asthmatic mice exhibited increased airway hyperresponsiveness, neutrophil infiltration, and airway mucus hypersecretion, upregulated retinoid-related orphan receptor-γt (RORγt) mRNA expression, and downregulated fork head box p3 (Foxp3) mRNA expression, which was concurrent with NLRP3 inflammasome activation and upregulation of caspase-1, IL-1β, and IL-18 expression in lung. Treatment of NLRP3 inflammasome inhibitors significantly attenuated airway hyperresponsiveness, airway inflammation, and reversed T helper 17 (Th17)/regulatory T (Treg) cell imbalance in asthmatic mice. We propose that the NLRP3/caspase-1/IL-1β pathway plays an important role in the pathological process of neutrophilic asthma and provides evidence that blocking this pathway could potentially be a treatment strategy to ameliorate airway inflammation in asthma after validation with future experimental and clinical studies.

Alkyl organophosphate flame retardants (OPFRs) induce lung inflammation and aggravate OVA-simulated asthmatic response via the NF-кB signaling pathway

Alkyl organophosphate flame retardants (OPFRs), tri-n-butyl phosphate (TnBP) and tris(2-butoxyethyl) phosphate (TBOEP), are ubiquitously detected in indoor and outdoor environments and their inhalation may result in lung damage. This study examined pulmonary toxicity after exposure to TnBP or TBOEP and investigated aggravation of inflammation and immunoreaction by TnBP in an ovalbumin (OVA)-induced mice model. Transcriptomics were used to further reveal the underlying mechanism. Exposure to TnBP or TBOEP resulted in pathological damage, including edema and thickened alveolar septum. In comparison with the control, enhanced levels of superoxide dismutase (SOD) (p < 0.01 in TnBP (High) group and p < 0.05 in TBOEP (High) group), glutathione peroxidase (GSH-px) (p < 0.05), malondialdehyde (MDA) (p < 0.01), and cytokines under a dose-dependent relationship were noted, and the expression of the Fkbp5/Nos3/MAPK/NF-кB signaling pathway (p < 0.01) was upregulated in the TnBP and TBOEP groups. Moreover, the combined exposure of TnBP and OVA exacerbated the allergic inflammatory response, including airway hyperresponsiveness, leukocytosis, cellular exudation and infiltration, secretion of inflammatory mediators, and higher expression of IgE (p < 0.01). Transcriptomics results demonstrated that the PI3K/Akt/NF-кB signal pathway was involved in TnBP-aggravated asthmatic mice. Exposure to TnBP or TBOEP resulted in oxidative damage and leukocyte-induced lung injury. TnBP can further facilitate OVA-induced asthma through an inflammatory response. This study is the first to reveal the pulmonary toxicity and potential mechanism induced by OPFRs through an in-vivo model.

MTMR14 Alleviates Chronic Obstructive Pulmonary Disease as a Regulator in Inflammation and Emphysema

Extensive inflammation and apoptosis in structural cells of the lung are responsible for the progression and pathogenesis of chronic obstructive pulmonary disease (COPD). Myotubularin-related protein 14 (MTMR14) has been shown to participate in various biological processes, including apoptosis, inflammation, and autophagy. Nonetheless, the role of MTMR14 in COPD remains elusive. In the present study, we explored the expression of MTMR14 in human lung tissues and investigated the effects of overexpressed MTMR14 on in vitro and in vivo COPD models. Moreover, one of the possible mechanisms of MTMR14 alleviating COPD was explored based on mitochondrial function and mitophagy homeostasis. The results showed that MTMR14 expression was reduced in COPD patients' lungs in comparison to control subjects. MTMR14 overexpression inhibited cigarette smoke extract-induced inflammation and apoptosis and improved mitochondrial function and mitophagy in vitro. Further verification was carried out in COPD model mice. MTMR14 overexpression inhibited lung inflammation and reduced levels of IL-6 and KC in bronchoalveolar lavage fluid, as well as prevented emphysema and a decline in lung function. Furthermore, MTMR14 overexpression improved mitochondrial function and mitophagy to a certain extent. Collectively, our data support the hypothesis that MTMR14 participates in the pathogenesis of COPD. Improving mitochondrial function and mitophagy homeostasis may be one of the mechanisms by which MTMR14 alleviates COPD and may potentially be a novel therapeutic target for COPD.

Epithelial microRNA-30a-3p targets RUNX2/HMGB1 axis to suppress airway eosinophilic inflammation in asthma

Background

Type 2-high asthma is a prominent endotype of asthma which is characterized by airway eosinophilic inflammation. Airway epithelial cells play a critical role in the pathogenesis of asthma. Our previous miRNA profiling data showed that miR-30a-3p was downregulated in bronchial epithelial cells from asthma patients. We hypothesize that epithelial miR-30a-3p plays a role in asthma airway inflammation.

Methods

We measured miR‐30a-3p expression in bronchial brushings of asthma patients (n = 51) and healthy controls (n = 16), and analyzed the correlations between miR‐30a-3p expression and airway eosinophilia. We examined whether Runt-related transcription factor 2 (RUNX2) was a target of miR‐30a-3p and whether RUNX2 bound to the promoter of high mobility group box 1 (HMGB1) by using luciferase reporter assay and chromatin immunoprecipitation (ChIP)-PCR. The role of miR‐30a-3p was also investigated in a murine model of allergic airway inflammation.

Results

We found that miR-30a-3p expression were significantly decreased in bronchial brushings of asthma patients compared to control subjects. Epithelial miR-30a-3p expression was negatively correlated with parameters reflecting airway eosinophilia including eosinophils in induced sputum and bronchial biopsies, and fraction of exhaled nitric oxide in asthma patients. We verified that RUNX2 is a target of miR-30a-3p. Furthermore, RUNX2 bound to the promoter of HMGB1 and upregulated HMGB1 expression. RUNX2 and HMGB1 expression was both enhanced in airway epithelium and was correlated with each other in asthma patients. Inhibition of miR-30a-3p enhanced RUNX2 and HMGB1 expression, and RUNX2 overexpression upregulated HMGB1 in BEAS-2B cells. Intriguingly, airway overexpression of mmu-miR-30a-3p suppressed Runx2 and Hmgb1 expression, and alleviated airway eosinophilia in a mouse model of allergic airway inflammation.

Conclusions

Epithelial miR-30a-3p could possibly target RUNX2/HMGB1 axis to suppress airway eosinophilia in asthma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-01933-x.

Small Proline-Rich Protein 3 Regulates IL-33/ILC2 Axis to Promote Allergic Airway Inflammation

Small proline-rich proteins (SPRRs), components of cornified cell envelope precursors, have recently been found to participate in airway diseases. However, their role in allergic airway inflammatory conditions remains unknown. Here, we explored the expression of SPRR3 in house dust mite (HDM)-sensitized/challenged mice and attempted to elucidate the regulatory role of SPRR3 in allergic airway inflammation. SPRR3 was identified via bioinformatics analysis of Gene Expression Omnibus (GEO) databases and further confirmed to be upregulated in the lungs of asthmatic mice. Knockdown of SPRR3 via the intratracheal route significantly inhibited eosinophils in bronchoalveolar lavage fluid (BALF) and suppressed the expressions of type 2 cytokines (IL-4, IL-5, and IL-13) in BALF and lung tissues. Further, SPRR3 knockdown reduced the expression of IL-33 and further attenuated the activation of the PI3K/AKT/NF-κB signaling pathway in the recruitment of group 2 innate lymphoid cells (ILC2s) to inhibit allergic airway inflammation. In vitro, SPRR3 siRNA could alleviate HDM-induced inflammatory responses in BEAS-2B cells. This study reveals the regulatory role of SPRR3 in allergic airway inflammation, identifying this protein as a potential novel therapeutic target for asthma.

Dexmedetomidine alleviates airway hyperresponsiveness and allergic airway inflammation through the TLR4/NF‑κB signaling pathway in mice

Dexmedetomidine (DEX) suppresses inflammatory responses and protects against organ injury. The aim of the present study was to investigate the effect of DEX on airway hyperresponsiveness (AHR) and allergic airway inflammation, as well as its underlying mechanism of action in a murine model of ovalbumin (OVA)-induced asthma. A total of 30 female BALB/c mice were divided into 6 groups (n=5 mice/group): Control, OVA, OVA + DEX (20, 30 or 50 µg/kg) and OVA + TAK-242 [a toll-like receptor 4 (TLR4) inhibitor]. The mice were intraperitoneally injected with 20, 30 or 50 µg/kg DEX 1 h before OVA challenge. AHR to inhaled methacholine (Mch) was measured, and the mice were sacrificed 24 h after the last challenge. AHR following Mch inhalation was measured using the FlexiVent apparatus. Hematoxylin and eosin, periodic acid-Schiff and Wright-Giemsa staining was performed to evaluate inflammatory cell infiltration in the lung tissue. The levels of IL-4, IL-5 and IL-13 in the bronchoalveolar lavage fluid were analyzed using ELISA, and their mRNA expression levels in the lung tissue were examined using reverse transcription-quantitative PCR. The protein expression of TLR4, NF-κB and phosphorylated (p)NF-κB in the lung tissue was also detected using immunohistochemistry. In the murine OVA-induced asthma model, DEX decreased AHR following Mch inhalation and reduced the infiltration of inflammatory cells. IL-4, IL-5 and IL-13 levels in the bronchoalveolar lavage fluid were significantly lower following DEX treatment. Furthermore, DEX treatment inhibited the expression of TLR4, NF-κB and p-NF-κB in the lung tissue and exhibited a similar effect to TAK-242 treatment. In conclusion, DEX may attenuate AHR and allergic airway inflammation by inhibiting the TLR4/NF-κB pathway. These results suggested that DEX may represent a potential anti-inflammatory agent for the treatment and management of patients with asthma.

CPP Applications in Immune Modulation and Disease Therapy

About 30 years ago, the discovery of CPP improved the therapeutic approach to treat diseases and extended the range of potential targets to intracellular molecules. There are potential drug candidates for FDA approval based on active studies in basic research, preclinical, and clinical trials. Various attempts by CPP application to control the diseases such as allergy, autoimmunity, cancer, and infection demonstrated a strategy to make a new drug pipeline for successful discovery of a biologic drug for immune modulation. However, there are still no CPP-based drug candidates for immune-related diseases in the clinical stage. To control immune responses successfully, not only increasing delivery efficiency of CPPs but also selecting potential target cells and cargoes could be important issues. In particular, as it becomes possible to control intracellular targets, efforts to find various novel potential target are being attempted. In this chapter, we focused on CPP-based approaches to treat diseases through modulation of immune responses and discussed for perspectives on future direction of the research for successful application of CPP technology to immune modulation and disease therapy in clinical trial.

Cyclo-VEGI inhibits bronchial artery remodeling in a murine model of chronic asthma

Purpose/Aim: In the context of asthma, airway bronchial remodeling and angiogenesis in the bronchial mucosa are well established. Cyclopeptidic-vascular endothelial growth inhibitor (cyclo-VEGI) is an inhibitor of the vascular endothelial growth factor (VEGF) receptor that increases the proliferation of endothelial cells and the formation of new vessels. However, changes in the bronchial arteries of patients with asthma have not been clearly elucidated. We investigated whether structural changes occurred in bronchial arteries, as well as the effects of cyclo-VEGI in a mouse model of chronic asthma (in vivo) and human fibroblasts (in vitro). Materials and Methods: A validated mouse model of allergic airway inflammation with ovalbumin (OVA) as the causative allergen was used for the study. Mice were treated with cyclo-VEGI or fluticasone during OVA challenge. In vitro experiments were conducted to determine whether fibroblasts proliferated following elastin exposure and the effects of cyclo-VEGI on them. Results: OVA sensitization and challenge led to greater perivascular smooth muscle area, more elastic fibers, and elevated expression of vascular cell adhesion molecule (VCAM)-1 antigen. These phenomena indicated changes to bronchial arteries. Cyclo-VEGI and fluticasone treatment both inhibited airway hyper-responsiveness and inflammation. Cyclo-VEGI-treated mice exhibited decreased perivascular smooth muscle area, elastin fibers, and VCAM-1 expression. Fluticasone-treated mice exhibited reductions in perivascular smooth muscle but not in perivascular elastin or VCAM-1 expression. In vitro, fibroblast proliferation was enhanced by elastin treatment, which was inhibited by cyclo-VEGI treatment. Eotaxin expression was elevated in elastin-treated fibroblasts and decreased with cyclo-VEGI treatment. Conclusions: Vascular remodeling occurred in our mouse model of chronic asthma. Cyclo-VEGI could reduce airway inflammation and hyper-responsiveness by inhibiting VCAM-1 expression and elastin deposition around the bronchial arteries.

Autoantibody of interleukin-17A induced by recombinant Mycobacterium smegmatis attenuates airway inflammation in mice with neutrophilic asthma

OBJECTIVE

Previous studies have shown Interleukin (IL)-17A as an important contributor to the development of severe asthma, which is mainly characterized by neutrophilic inflammation and less response to corticosteroids. Consequently, the IL-17A-neutrophil axis could be a potential therapeutic target. Previously, we constructed a recombinant Mycobacterium smegmatis (rMS) expressing fusion protein Ag85A-IL-17A, and confirmed it could induce production of IL-17A autoantibody in vivo. This study uses a murine model of neutrophilic asthma to further investigate the effects of rMS on airway inflammation.

METHODS

DO11.10 mice were divided into four groups: phosphate buffered saline (PBS), asthma, rMS and MS. This murine model of neutrophilic asthma was established with ovalbumin (OVA) challenge, whereby PBS, rMS and MS were administered intranasally. Anti-inflammatory effects on inflammatory cell infiltration and expression of inflammatory mediators in bronchoalveolar lavage fluid (BALF) were evaluated, along with histopathological changes in lung tissues.

RESULTS

A sustained high-titer IL-17A autoantibody was detected in sera of the rMS group. Compared to the asthma group, the number of neutrophils, IL-17A, CXCL-1 levels and MPO activity in the rMS group were all significantly reduced (p < 0.01). Histological analysis showed rMS remarkably suppressed inflammatory infiltration around bronchia. The inflammation score and the mucus score in the rMS group were both significantly lower than those in the asthma group (p < 0.001).

CONCLUSION

rMS ameliorated airway inflammation in mice with neutrophilic asthma caused by inducing IL-17A autoantibody and regulating the IL-17A-neutrophil axis, thus offering a possible novel treatment for neutrophilic asthma.

Environmental allergens house dust mite-induced asthma is associated with ferroptosis in the lungs

Previous studies have indicated that allergens such as house dust mites (HDM) in the environment can induce allergic asthma. Ferroptosis is a newly discovered form of regulatory cell death characterized by aberrant lipid peroxidation and the accumulation of reactive oxygen species (ROS) in cells. However, whether ferroptosis participates in the pathological process of asthma remains to be elucidated. The present study used a HDM-induced mouse asthma model to determine the effect of HDM exposure on allergic asthma and its underlying mechanisms. Female BALB/c mice were intranasally exposed to HDM to induce allergic asthma. Airway hyperresponsiveness (AHR), lung inflammation, mucus secretion, IgE levels, cytokine levels and inflammatory cell counts in bronchoalveolar lavage fluid (BALF) were investigated. In addition, the morphological changes of mitochondria, ROS levels, glutathione (GSH) levels and changes in ferroptosis pathway proteins were also determined in murine lungs. As a result, HDM exposure significantly increased AHR, inflammatory cell infiltration and mucus secretion around the airways. Furthermore, elevated IgE levels in the BALF, lung eosinophilia and a concomitant increase in IL-13 and IL-5 levels in BALF were observed. HDM inhalation increased ROS and decreased GSH levels in the lungs. HDM inhalation induced dysmorphic small mitochondria with decreased crista, as well as condensed, ruptured outer membranes. Western blotting demonstrated that the activities of glutathione peroxidase 4 and catalytic subunit solute carrier family 7 member 11 were significantly decreased, and that protein expression levels of acyl-CoA synthetase long-chain family member 4 and 15 lipoxygenase 1 were upregulated compared with mice in the normal control group. Overall, these results indicated that the AHR, airway inflammation, lipid peroxidation and ROS levels increased in HDM-induced asthma, and that HDM inhalation induced ferroptosis in the lungs, which helped to form an improved understanding of the pathogenesis of allergic asthma.

Ginsenoside Rg3 ameliorates allergic airway inflammation and oxidative stress in mice

Background

Ginsenoside Rg3, isolated from Panax ginseng, has anti-inflammatory and anti-tumor activities. It is known to reduce inflammation in acute lung injury in mice, and to reduce the expression of inflammatory cytokines and COX-2 in human asthmatic airway epithelium. In this study, we attempted to determine whether ginsenoside Rg3 inhibits airway inflammation, oxidative stress, and airway hyperresponsiveness (AHR) in the lungs of asthmatic mice. We also investigated its effects on oxidative stress and the inflammatory response in tracheal epithelial cells.

Methods

Asthma symptoms were induced in female BALB/c mice sensitized with ovalbumin (OVA). Mice were divided into five groups: normal controls, OVA-induced asthmatic controls, and asthmatic mice treated with ginsenoside Rg3 or prednisolone by intraperitoneal injection. Inflammatory BEAS-2B cells (human tracheal epithelial cells) treated with ginsenoside Rg3 to investigate its effects on inflammatory cytokines and oxidative responses.

Results

Ginsenoside Rg3 treatment significantly reduced eosinophil infiltration, oxidative responses, airway inflammation, and AHR in the lungs of asthmatic mice. Ginsenoside Rg3 reduced Th2 cytokine and chemokine levels in bronchoalveolar lavage fluids and lung. Inflammatory BEAS-2B cells treated with ginsenoside Rg3 reduced the eotaxin and pro-inflammatory cytokine expressions, and monocyte adherence to BEAS-2B cells was significantly reduced as a result of decreased ICAM-1 expression. Furthermore, ginsenoside Rg3 reduced the expression of reactive oxygen species in inflammatory BEAS-2B cells.

Conclusion

Ginsenoside Rg3 is a potential immunomodulator that can ameliorate pathological features of asthma by decreasing oxidative stress and inflammation

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Ginsenoside Rg3 reduced eosinophil infiltration, and airway hyperresponsiveness in the lungs of asthmatic mice.

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Ginsenoside Rg3 inhibited oxidative responses in the lungs.

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Ginsenoside Rg3 reduced the levels of Th2 cytokines in BALF and lung.

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Ginsenoside Rg3 inhibited monocyte cell adherence to tracheal epithelial cells.

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Ginsenoside Rg3 reduced the levels of pro-inflammatory cytokines in tracheal epithelial cells.

Tiotropium bromide has a more potent effect than corticosteroid in the acute neutrophilic asthma mouse model

Background

Neutrophilic asthma (NeuA) is usually resistant to corticosteroids. Tiotropium bromide (TIO) is a bronchodilator that is used as an add-on therapy to inhaled corticosteroid and long-acting β2 agonist in asthma treatment. However, the role of TIO in NeuA is not fully known. Thus, the aim of this study was to evaluate the effect of TIO on NeuA compared to that of corticosteroids.

Methods

C57BL/6 female mice were sensitized with ovalbumin and lipopolysaccharide to induce neutrophilic inflammation. Dexamethasone (DEX) was administered on days 14, 17, 20, and 23. TIO was inhaled on days 21, 21, and 23. On day 24, mice were sacrificed. Airway hyper-responsiveness, levels of cytokines in bronchoalveolar lavage (BAL) and lung homogenates, and lung tissue histopathology were compared between the two groups.

Results

Neutrophil counts, T helper 2 cells (T_H2)/T_H17 cytokines, and pro-inflammatory cytokine in BAL fluids were elevated in the NeuA group. TIO group showed lower total cells, neutrophil counts, and eosinophil counts in BAL fluids than the DEX group (p<0.001, p<0.05, and p<0.001, respectively). Airway resistance was attenuated in the TIO group but elevated in the NeuA group (p<0.001). Total protein, interleukin (IL)-5, and IL-17A levels in BAL fluids were lower in the TIO group than in the NeuA group (all p<0.05).

Conclusion

TIO showed more potent effects than DEX in improving airway inflammation and attenuating airway resistance in NeuA.

Tyrosol improves ovalbumin (OVA)-induced asthma in rat model through prevention of airway inflammation

Asthma is an inflammatory disease that affects many people around the world, especially persons at paediatric age group. The effectiveness of tyrosol, a natural phenolic compound, was examined in the asthma model induced by ovalbumin (OVA). For this purpose, four groups, each consisting of eight rats, were arranged. For 21 days, physiological saline solution was treated to the control group and OVA was treated to the groups of OVA, OVA + dexamethasone (Dexa) and OVA + tyrosol groups, intraperitoneally and through inhalation. Additionally, 0.25 mg/kg Dexa was treated to the OVA + Dexa group and 20 mg/kg tyrosol to the OVA + tyrosol group by oral gavage. Serum, blood, bronchoalveolar lavage fluid (BALF) and lung tissues of the rats were examined. It was observed that MDA level decreased, GSH level and GPx activity increased, and there was no change in CAT activity in lung tissues of the tyrosol treatment groups. It was also observed that NF-κB, TNF-α, IL-4, IL-5, IL-13, IFN-γ and IgE levels decreased compared to the OVA group in lung tissue and serum samples except for serum NF-κB and IL-4. However, no effect on IL-1 β level was observed. In addition, it was determined that tyrosol treatment increased the IL-10 level on both tissue samples. The results of the histopathological investigation of lung tissue showed that tyrosol significantly ameliorated OVA-induced histopathological lesions. Additionally, PAS staining showed that mucus hypersecretion was significantly reduced with the use of tyrosol. In addition, it was determined that the number of eosinophils decreased significantly in blood and BALF samples. The obtained results showed that tyrosol possessed antioxidant and anti-inflammatory features on OVA-induced rats and preserved tissue architecture.