CpG-ODNs and Budesonide Act Synergistically to Improve Allergic Responses in Combined Allergic Rhinitis and Asthma Syndrome Induced by Chronic Exposure to Ovalbumin by Modulating the TSLP-DC-OX40L Axis

Research progress in OX40/OX40L in allergic diseases

OX40/OX40L are costimulatory molecules in the tumor necrosis factor superfamily. Numerous studies have shown that OX40/OX40L are involved in immune regulation, especially in the proliferation and differentiation of T cells and the generation of memory T cells, which play important roles in allergic diseases. In recent years, the use of OX40/OX40L as therapeutic targets for treating T-cell-mediated diseases has attracted the interest of scholars. This paper reviews the role of OX40/OX40L in allergic diseases and the progress in clinical treatments targeting this signaling pathway.

Alanyl-Glutamine Inhibits the Epithelial-Mesenchymal Transition of Airway Epithelial Cells in Asthmatic Mice via DPP4-SIRT1 Pathway

INTRODUCTION

Alanyl-glutamine (Ala-Gln) is a compound known for its protective effects in various tissue injuries. However, its role in asthma-related lung injuries remains underexplored. This study investigates the mechanisms by which Ala-Gln modulates sDPP4-induced airway epithelial-mesenchymal transition and ovalbumin (OVA)-induced asthma in a mouse model.

METHODS

An asthma model was established in female C57BL/6 J mice by using OVA. CD4+ T cells and bronchial epithelial cells (BECs) were isolated from the spleen and bronchi of the mice, respectively. Interventions included recombinant sCD26/sDPP4 protein, Ala-Gln, and EX527 (a SIRT1 inhibitor). Flow cytometry was used to assess Th17 and Treg cell populations. Mice were treated with Ala-Gln, EX527, and budesonide (BUD). Histopathological changes in lung tissues were evaluated using hematoxylin-eosin and Masson staining. White blood cell counts were measured with a hematology analyzer. The expression levels of DPP4, IL-17, SIRT1, SMAD2/3, N-cadherin, E-cadherin, MMP9, and α-SMA proteins were analyzed.

RESULTS

Treatment with recombinant sCD26/sDPP4 resulted in decreased E-cadherin expression in BECs and increased levels of α-SMA, MMP9, and N-cadherin, effects that were mitigated by Ala-Gln. Ala-Gln also prevented the reduction in SIRT1 expression in BECs and the increase in Th17 cell differentiation induced by recombinant sCD26/sDPP4. EX527 administration alongside Ala-Gln reversed these changes and enhanced the phosphorylation of SMAD2/3 through SIRT1 signaling. BUD alone reduced inflammation and fibrosis in bronchial tissue and lowered the Th17/Treg ratio in peribronchial lymph nodes. The therapeutic effect of BUD was further improved with concurrent Ala-Gln treatment.

CONCLUSION

Ala-Gln can inhibit BEC fibrosis and Th17 cell differentiation mediated by recombinant sCD26/sDPP4 through the SIRT1 pathway. Combined with BUD, Ala-Gln enhanced therapeutic efficacy in OVA-induced asthma in mice, which could offer improved outcomes for asthmatic patients with elevated DPP4 levels.

Knockdown of DDX3Y alleviates ovalbumin-induced allergic rhinitis in mice by regulating NF-κB pathway

Allergic rhinitis (AR), a type of chronic inflammatory disease that exists in the nasal mucosa, significantly impacts the quality of life. DDX3Y gene encodes an RNA helicase belonging to the DEAD-box protein family and is part of the DDX3 subfamily that affects the progression of multiple diseases. However, the specific role and mechanisms of DDX3Y in AR remain unclear. This study investigates the effects of DDX3Y knockdown on ovalbumin (OVA)-induced AR in mice. We found that DDX3Y is highly expressed in the nasal mucosa of AR mice. Knockdown of DDX3Y in OVA-induced AR mice significantly alleviated nasal manifestations, reduced immunoglobulin E and histamine levels, and improved nasal mucosal histopathology. Additionally, knockdown of DDX3Y suppressed secretion of inflammatory factor nuclear factor kappa B (NF-κB) phosphorylation, thereby mitigating local inflammatory responses. These findings suggested that targeting DDX3Y could offer a novel therapeutic strategy for managing AR by modulating the NF-κB pathway.

Isoorientin alleviates ovalbumin-stimulated allergic rhinitis in mice by restoring Th1/Th2 balance

Allergic rhinitis (AR) is a chronic, non-infectious inflammatory condition of the nasal mucosa mediated by IgE. There is a need for the development of novel medications to treat this ailment. Isoorientin is a naturally occurring flavonoid that possesses antioxidant, anti--inflammatory, and various other advantageous characteristics. However, its potential effects on AR remain unclear. This study evaluates the therapeutic effects of isoorientin on ovalbumin (OVA)-induced allergic rhinitis (AR) in mice and explores the underlying mechanism. Our study revealed that isoorientin administration effectively decreased the frequency of nose rubbing and sneezing in AR mice. The groups treated with isoorientin showed a significant decrease in serum levels of IgE and histamine, with reductions of 40% and 30%, respectively. Isoorientin ameliorated inflammation of the nasal mucosa and restored the Th1/Th2 balance. In addition, isoorientin inhibited the activation of the NF-κB pathway in nasal tissues. In summary, Isoorientin alleviates OVA-stimulated AR in mice by restoring Th1/Th2 balance and blocking the NF-κB pathway. Thus, isoorientin exhibits promise as a natural therapeutic agent for allergic rhinitis.

Morita-Baylis-Hillman adduct 2-(3-hydroxy-1-methyl-2-oxoindolin-3-il) acrylonitrile (CISACN) ameliorates the pulmonary allergic inflammation in CARAS model by increasing IFN-γ/IL-4 ratio towards the Th1 immune response

Combined allergic rhinitis and asthma syndrome (CARAS) is an airway-type 2 immune response with a profuse inflammatory process widely affecting the world population. Due to the compromise of quality of life and the lack of specific pharmacotherapy, the search for new molecules becomes relevant. This study aimed to evaluate the effectiveness of the Morita-Bailys-Hillman adduct (CISACN) treatment in the CARAS experimental model. Female BALB/c mice were ovalbumin (OVA) -sensitized and -challenged and treated with CISACN. The treatment decreased the eosinophil migration to the nasal and lung cavities and tissues and the goblet cell hyperplasia/hypertrophy, attenuated airway hyperactivity by reducing the hyperplasia/hypertrophy of the smooth muscle and the extracellular matrix's thickness. Also, the treatment reduced the clinical signs of rhinitis as nasal rubbing and sneezing in a histamine-induced nasal hyperreactivity assay. The immunomodulatory effect of CISACN was by reducing OVA-specific IgE serum level, and IL-33, IL-4, IL-13, and TGF-β production, dependent on IFN-γ increase. Furthermore, the effect of CISACN on lung granulocytes was by decreasing the p-p38MAPK/p65NF-κB signaling pathway. Indeed, CISACN reduced the p38MAPK and p65NF-κB activation. These data demonstrated the anti-inflammatory and immunomodulatory effects of the CISACN with scientific support to become a pharmacological tool to treat airway inflammatory diseases.

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.

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.

A CpG-Oligodeoxynucleotide Suppresses Th2/Th17 Inflammation by Inhibiting IL-33/ST2 Signaling in Mice from a Model of Adoptive Dendritic Cell Transfer of Smoke-Induced Asthma

Tobacco smoke exposure is a major environmental risk factor that facilitates the development and progression of asthma. Our previous study showed that CpG oligodeoxynucleotide (CpG-ODN) inhibits thymic stromal lymphopoietin (TSLP)-dendritic cells (DCs) to reduce Th2/Th17-related inflammatory response in smoke-related asthma. However, the mechanism underlying CpG-ODN -downregulated TSLP remains unclear. A combined house dust mite (HDM)/cigarette smoke extract (CSE) model was used to assess the effects of CpG-ODN on airway inflammation, Th2/Th17 immune response, and amount of IL-33/ST2 and TSLP in mice with smoke-related asthma induced by adoptive transfer of bone-marrow-derived dendritic cells (BMDCs) and in the cultured human bronchial epithelium (HBE) cells administered anti-ST2, HDM, and/or CSE. In vivo, compared to the HDM alone model, the combined HDM/CSE model had aggravated inflammatory responses, while CpG-ODN attenuated airway inflammation, airway collagen deposition, and goblet cell hyperplasia and reduced the levels of IL-33/ST2, TSLP, and Th2/Th17-cytokines in the combined model. In vitro, IL-33/ST2 pathway activation promoted TSLP production in HBE cells, which could be inhibited by CpG-ODN. CpG-ODN administration alleviated Th2/Th17 inflammatory response, decreased the infiltration of inflammatory cells into the airway, and improved the remodeling of smoke-related asthma. The underlying mechanism may be that CpG-ODN inhibits the TSLP-DCs pathway by downregulating the IL-33/ST2 axis.

Nerve growth factor causes epinephrine release dysfunction by regulating phenotype alterations and the function of adrenal medullary chromaffin cells in mice with allergic rhinitis

The presence of allergic rhinitis (AR) is an increased risk factor for the occurrence of bronchial asthma (BA). Nerve growth factor (NGF), in addition to its key role in the development and differentiation of neurons, may also be an important inflammatory factor in AR and BA. However, the pathogenesis of the progression of AR to BA remains to be elucidated. The present study aimed to investigate the ability of NGF to mediate nasobronchial interactions and explore possible underlying molecular mechanisms. In the present study, an AR mouse model was established and histology of nasal mucosa tissue injury was determined. The level of phenylethanolamine N‑methyl transferase in adrenal medulla was determined by immunofluorescence. Primary adrenal medullary chromaffin cells (AMCCs) were isolated and cultured from the adrenal medulla of mice. The expression levels of synaptophysin (SYP), STAT1, JAK1, p38 and ERK in NGF‑treated and untreated AMCCs were detected by reverse‑transcription‑quantitative PCR and western blotting. The epinephrine (EPI) and norepinephrine (NE) concentrations were measured by ELISA. It was found that the expression of SYP in AMCCs was enhanced in the presence of NGF, whereas, the concentration of EPI decreased significantly under the same conditions. Furthermore, NGF mediated the phenotypic and functional changes of AMCCs, resulting in decreased EPI secretion via JAK1/STAT1, p38 and ERK signaling. In conclusion, these findings could provide novel evidence for the role of NGF in regulating neuroendocrine mechanisms.

Upregulated expression of substance P and NK1R in blood monocytes and B cells of patients with allergic rhinitis and asthma

Increased expression of substance P (SP) and neurokinin-1 receptor (NK1R) has been noticed in patients with allergic rhinitis (AR) and allergic asthma (AA). However, little is known of the expression of SP and NK1R in monocytes and B cells of AR and AA. In the present study, the expression levels of SP and NK1R were determined by flow cytometry and mouse AR and AA models. The results showed that both percentages of SP+ monocytes and SP+ B cells, and mean fluorescence intensity (MFI) of SP in monocytes were elevated in the blood of AA and AR combined with AA (ARA) patients. Similarly, the percentages of NK1R+ monocytes were elevated in the blood of AR, AA, and ARA patients. Allergens Artemisia sieversiana wild allergen extract (ASWE), house dust mite extract (HDME), and Platanus pollen allergen extract (PPE) increased the expression density of SP molecules (determined by MFI) in an individual monocyte of AR patients. HDME and PPE appeared to enhance SP and NK1R expression in the B cells of ARA and AR patients. In the mouse AR and AA models, the percentages of NK1R+ monocytes and B cells were elevated in blood following OVA (ovalbumin) sensitization and challenge. Knocking out the FcεRI molecule completely abolished the OVA-induced upregulation of expression of NK1R in monocytes and B cells of AA mice. In conclusion, upregulated expressions of SP and NK1R may contribute to the pathogenesis of airway allergy.

CCR3 gene knockout in bone marrow cells ameliorates combined allergic rhinitis and asthma syndrome (CARAS) by reducing airway inflammatory cell infiltration and Th2 cytokines expression in mice model

The present study aims to investigate the effects of CCR3 gene knockout in bone marrow cells (CCR3-KO) on the mouse model of combined allergic rhinitis and asthma syndrome (CARAS). It was found that CCR3-KO significantly reduced eosinophil (EOS) migration into the nasal (NALF) and bronchoalveolar (BALF) cavities of mice, and decreased Th2 cytokines (such as, IL-4, IL-5 and IL-13) levels in nasal mucosa and lung tissues. In addition, histological analysis showed that the damage degree of nasal mucosa structure in ovalbumin (OVA) modulated CCR3-KO mice was significantly less than that in OVA modulated Wild type (WT) mice, with reduced inflammatory cell infiltration and nasal mucus secretion. The infiltration of inflammatory cells in lung tissue was significantly reduced, and the proliferation of lung smooth muscle layer and extracellular matrix (ECM) production were decreased. Symptom analysis showed that CCR3-KO can reduced allergic rhinitis (AR) signals as nose scratching and sneezing. It was also found CCR3-KO reduce OVA-induced weight loss. The results showed that CCR3-KO could reduce the symptoms of allergic inflammation in CARAS mice by reducing airway inflammatory cell infiltration and down-regulating the expression of Th2 cytokines, and CCR3 gene could be used as a target gene for the treatment of CARAS.

Petroleum extract of Farfarae Flos alleviates nasal symptoms by regulating the Th1-Th2 cytokine balance in a mouse model of Allergic Rhinitis

Farfarae Flos is a traditional Chinese medicine that has long been used to treat allergies. In this study, we aimed to investigate the effect of a petroleum extract of Farfarae Flos (PEFF) in a mouse model of allergic rhinitis (AR) and to explore the underlying molecular mechanisms of action. An animal model of AR was established by sensitization and challenge of BALB/c mice with ovalbumin (OVA). PEFF was administered intranasally and AR nasal symptoms were assessed on a semi-quantitative scale according to the frequencies of nose rubbing and sneezing and the degree of rhinorrhea. The mechanism of action of PEFF was evaluated by histological analysis of nasal mucosa architecture and inflammatory status; ELISA-based quantification of serum OVA-specific IgE, interferon-γ (IFN-γ), and interleukin-4 (IL-4) concentrations; and immunohistochemical and western blot analysis of T-bet and GATA3 protein expression in nasal mucosa and spleen tissues. The results showed intranasal administration of PEFF alleviated AR symptom scores and reduced both the infiltration of inflammatory cells and tissue damage in the nasal mucosa. PEFF significantly decreased serum concentrations of OVA-specific IgE (P<0.01) and IL-4 (P<0.05) and significantly increased IFN-γ (P<0.01). PEFF also upregulated the expression of T-bet protein (P<0.05) but downregulated GATA3 protein (P<0.05) in nasal mucosa and spleen tissues. In conclusion, PEFF effectively reduces AR nasal symptoms and serum IgE levels in a mouse model and may act by correcting the imbalance between Th1 and Th2 responses.

4-Carvomenthenol ameliorates the murine combined allergic rhinitis and asthma syndrome by inhibiting IL-13 and mucus production via p38MAPK/NF-κB signaling pathway axis

The aim of this study was to analyze the 4-carvomenthenol (carvo) oral treatment on the experimental model of the combined allergic rhinitis and asthma syndrome (CARAS). BALB/c mice were OVA-sensitized on day zero and 7th (50 μg/mL OVA in 10 mg/mL Al (OH)3) and OVA-challenged (5 mg/mL, 20 μL/animal) for three weeks. In the last week, the animals were dally challenged with aerosol of OVA and the carvo treatment (12.5, 25 or 50 mg/kg) occurred one hour before each OVA-challenge. Data were analyzed and p < 0.05 was considered significant. Carvo (12.5-50 mg/kg) decreased significantly the eosinophil migration into the nasal (NALF) and bronchoalveolar (BALF) cavities as well as on the nasal and lung tissues of sick animals. The treatment also decreased mucus production on both tissue sections stained with PAS (periodic acid-Schiff satin). In addition, the histological analyzes demonstrated that sick mice presented hyperplasia and hypertrophy of the lung smooth muscle layer followed by increasing of extracellular matrix and carvo (50 mg/kg) inhibited these asthmatic parameters. We analyzed the allergic rhinitis signals as nasal frictions and sneezing and observed that carvo decreased these two signals as well as serum OVA-specific IgE titer, type 2 cytokine synthesis, mainly IL-13, with increasing of IL-10 production. Decreasing of IL-13 production corroborated with decreasing of mucus production and these effects were dependent on p38MAPK/NF-κB(p65) signaling pathway inhibition. Therefore, these data demonstrated that a monoterpene of essential oils presents anti-allergic property on an experimental model of CARAS suggesting a new drug prototype to treat this allergic syndrome.

Yupingfeng Granule Improves Th2-Biased Immune State in Microenvironment of Hepatocellular Carcinoma through TSLP-DC-OX40L Pathway

The tumor immunological microenvironment in hepatocellular carcinoma (HCC) is the T-helper (Th) 2 dominant inhibition state. Improving the immunosuppressive tumor microenvironment represents an important strategy for HCC treatment. TSLP-OX40L pathway is a target to improve Th2 immunosuppression. Yupingfeng granule (YPF) is clinically used to effectively improve the immune status of HCC. In this study, YPF increased the percentage of mature dendritic cells (DCs) and decreased levels of TSLP, TSLPR, and OX40L in tumor and adjacent tissues of the orthotopic-HCC mice model. This occurs together with the decreased levels of Th2 cytokines and increased levels of Th1 cytokines and Th1/Th2 ratio. In vitro experiment showed that YPF not only increased the percentage of mature DCs and stimulated IL-12 secretion in DCs but also reduced the positive rate of OX40L expression, decreased the proportion of CD4⁺ IL-13⁺ T cells, increased levels of Th1 cytokines, and decreased levels of Th2 cytokines from TSLP-treated DCs. In summary, these findings demonstrated that YPF promoted the maturation of DCs, decreased OX40L in TSLP-induced DCs, and improved the immunosuppressive state of Th2 in HCC microenvironment. Our results suggest that the mechanism underlying the improving effect of YPF on the immunosuppression is related to the DC-mediated TSLP-OX40L pathway.

Airway inflammation and remodeling of cigarette smoking exposure ovalbumin-induced asthma is alleviated by CpG oligodeoxynucleotides via affecting dendritic cell-mediated Th17 polarization

Cigarette smoking (CS) is common in asthma, aggravating inflammatory reactions. However, the current treatment strategies for asthma are still not effective enough, and novel therapeutic approaches are required for CS-induced asthmatic disorders. We here investigated the ability of CpG oligodeoxynucleotides (CpG-ODNs) to inhibit airway inflammation and remodeling in ovalbumin (OVA)-associated asthma in mice exposed to chronic CS, revealing potential mechanistic insights. Lung tissue specimens were histologically analyzed. Th1/Th2/Th17 associated cytokines in serum, bronchoalveolar lavage fluid (BALF), and lung specimens were quantitated by ELISA, qRT-PCR and immunoblot. Parameters of bone marrow-derived dendritic cells (BMDCs) functions were evaluated as well. The results showed that BALB/c mice after CS and OVA treatments developed an asthmatic phenotype with airway inflammation involving both eosinophils and neutrophils, goblet cell metaplasia, airway remodeling, and elevated OVA-specific serum IgE, serum IL-17A, and BALF Th17/Th2 associated cytokines. CpG-ODNs and budesonide were found to synergistically inhibit inflammatory cell recruitment in the lung, airway remodeling, IgE synthesis, and Th17/Th2 associated cytokines. Mechanistically, CpG-ODNs and budesonide acted synergistically on BMDCs via downregulation of TSLP receptor (TSLPR) and IL-23 production, and subsequently contributed to dampen Th17/Th2 polarization in CS-associated asthma. In conclusion, combined administration of CpG-ODNs and budesonide, in a synergistic manner, inhibits airway inflammation, and tissue remodeling mediated by BMDCs by regulating IL-23 secretion and blocking TSLP signaling, which subsequently contribute to alleviate Th17/Th2 imbalance in CS-associated asthma.

Intranasal Application of Budesonide Attenuates Lipopolysaccharide-Induced Acute Lung Injury by Suppressing Nucleotide-Binding Oligomerization Domain-Like Receptor Family, Pyrin Domain-Containing 3 Inflammasome Activation in Mice

Aim

To investigate the protective effects of budesonide against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in a murine model and its underlying mechanism.

Methods

Adult male C57BL/6 mice were divided into three groups: control, ALI, and ALI + budesonide groups. LPS (5 mg/kg) was intratracheally injected to induce ALI in mice. Budesonide (0.5 mg/kg) was intranasally given 1 h before LPS administration in the ALI + budesonide group. Twelve hours after LPS administration, all mice were sacrificed. Hematoxylin-eosin staining and pathological scores were used to evaluate pathological injury. Bronchoalveolar lavage was performed. The numbers of total cells, neutrophils, and macrophages in the bronchoalveolar lavage fluid (BALF) were counted. Enzyme-linked immunosorbent assay was employed to detect the proinflammatory cytokines in BALF and serum, including tumor necrosis factor- (TNF-) α, monocyte chemoattractant protein- (MCP-) 1, and interleukin- (IL-) 1β. The expression of the nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome was detected by western blotting. A lethal dose of LPS (40 mg/kg, intraperitoneally) was injected to evaluate the effects of budesonide on survival rates.

Results

Budesonide pretreatment dramatically attenuated pathological injury and reduced pathological scores in mice with ALI. Budesonide pretreatment obviously reduced the numbers of total cells, neutrophils, and macrophages in the BALF of mice with ALI. Additionally, budesonide dramatically reduced TNF-α and MCP-1 expression in the BALF and serum of mice with ALI. Budesonide significantly suppressed NLRP3 and pro-caspase-1 expression in the lung and reduced IL-1β content in the BALF, indicating that budesonide inhibited the activation of the NLRP3 inflammasome. Furthermore, we found that budesonide improved the survival rates of mice with ALI receiving a lethal dose of LPS.

Conclusion

Suppression of NLRP3 inflammasome activation in mice via budesonide attenuated lung injury induced by LPS in mice with ALI.

IL-37 alleviates house dust mite-induced chronic allergic asthma by targeting TSLP through the NF-κB and ERK1/2 signaling pathways

Interleukin (IL)-37 has been described as a negative regulator of immune responses and is critical for asthma pathogenesis, but the mechanisms behind the protective role of IL-37 against allergic asthma are less well understood. We show here that IL-37 administered intranasally inhibited house dust mite (HDM)-induced chronic airway eosinophilic inflammation, goblet cell hyperplasia, peribronchial collagen deposition and airway hyperresponsiveness (AHR) to methacholine. In contrast to a weakened Th2 response in the lung that was characterized by the downregulation of Th2-associated cytokines and chemokines in IL-37-treated mice, IL-37 has no effect on relevant markers of systemic Th2 immune including serum immunoglobulins expression and in vitro production of Th2-associated cytokines by splenocytes on HDM recall. We demonstrated that the production of thymic stromal lymphopoietin (TSLP) in the lung tissue was associated with IL-37. Importantly, compared with IL-37 alone, TSLP coadministration with IL-37 restored HDM-induced airway inflammation and structural alterations, increased AHR to methacholine and promoted Th2-associated cytokine production. We further found that IL-37 inhibited the induction of TSLP expression by the main antigen of house dust mite, Der p1, by suppressing NF-κB and extracellular signal regulated kinase 1/2 (ERK1/2) activation in human bronchial epithelial (16-HBE) cells in vitro. These data highlight the importance of TSLP in IL-37-mediated protective role in asthma. IL-37 might represent a useful innovative and alternative therapy to control TSLP production in the airway.