Modeling TH 2 responses and airway inflammation to understand fundamental mechanisms regulating the pathogenesis of asthma

Critically-ill COVID-19 susceptibility gene CCR3 shows natural selection in sub-Saharan Africans

The prevalence of COVID-19 critical illness varies across ethnicities, with recent studies suggesting that genetic factors may contribute to this variation. The aim of this study was to investigate natural selection signals of genes associated with critically-ill COVID-19 in sub-Saharan Africans. Severe COVID-19 SNPs were obtained from the HGI website. Selection signals were assessed in 661 sub-Sahara Africans from 1000 Genomes Project using integrated haplotype score (iHS), cross-population extended haplotype homozygosity (XP-EHH), and fixation index (Fst). Allele frequency trajectory analysis of ancient DNA samples were used to validate the existing of selection in sub-Sahara Africans. We also used Mendelian randomization to decipher the correlation between natural selection and critically-ill COVID-19. We identified that CCR3 exhibited significant natural selection signals in sub-Sahara Africans. Within the CCR3 gene, rs17217831-A showed both high iHS (Standardized iHS = 2) and high XP-EHH (Standardized XP-EHH = 2.5) in sub-Sahara Africans. Allele frequency trajectory of CCR3 rs17217831-A revealed natural selection occurring in the recent 1,500 years. Natural selection resulted in increased CCR3 expression in sub-Sahara Africans. Mendelian Randomization provided evidence that increased blood CCR3 expression and eosinophil counts lowered the risk of critically ill COVID-19. Our findings suggest that sub-Saharan Africans are resistant to critically ill COVID-19 due to natural selection and identify CCR3 as a potential novel therapeutic target.

Direct vagus nerve stimulation: A new tool to control allergic airway inflammation through α7 nicotinic acetylcholine receptor

BACKGROUND AND PURPOSE

Asthma is characterized by airway inflammation, mucus hypersecretion, and airway hyperresponsiveness. The use of nicotinic agents to mimic the cholinergic anti-inflammatory pathway (CAP) controls experimental asthma. Yet, the effects of vagus nerve stimulation (VNS)-induced CAP on allergic inflammation remain unknown.

EXPERIMENTAL APPROACH

BALB/c mice were sensitized and challenged with house dust mite (HDM) extract and treated with active VNS (5 Hz, 0.5 ms, 0.05-1 mA). Bronchoalveolar lavage (BAL) fluid was assessed for total and differential cell counts and cytokine levels. Lungs were examined by histopathology and electron microscopy.

KEY RESULTS

In the HDM mouse asthma model, VNS at intensities equal to or above 0.1 mA (VNS 0.1) but not sham VNS reduced BAL fluid differential cell counts and alveolar macrophages expressing α7 nicotinic receptors (α7nAChR), goblet cell hyperplasia, and collagen deposition. Besides, VNS 0.1 also abated HDM-induced elevation of type 2 cytokines IL-4 and IL-5 and was found to block the phosphorylation of transcription factor STAT6 and expression level of IRF4 in total lung lysates. Finally, VNS 0.1 abrogated methacholine-induced hyperresponsiveness in asthma mice. Prior administration of α-bungarotoxin, a specific inhibitor of α7nAChR, but not propranolol, a specific inhibitor of β2-adrenoceptors, abolished the therapeutic effects of VNS 0.1.

CONCLUSION AND IMPLICATIONS

Our data revealed the protective effects of VNS on various clinical features in allergic airway inflammation model. VNS, a clinically approved therapy for depression and epilepsy, appears to be a promising new strategy for controlling allergic asthma.

Exposure to ephedrine attenuates Th1/Th2 imbalance underlying OVA-induced asthma through airway epithelial cell-derived exosomal lnc-TRPM2-AS

Although various anti-inflammatory medications, such as ephedrine, are employed to manage cough-variant asthma, their underlying mechanisms are yet to be fully understood. Recent studies suggest that exosomes derived from airway epithelial cells (AECs) contain components like messenger RNAs (mRNAs), micro-RNAs (miRNAs), and long noncoding RNA (lncRNA), which play roles in the occurrence and progression of airway inflammation. This study investigates the influence of AEC-derived exosomes on the efficacy of ephedrine in treating cough-variant asthma. We established a mouse model of asthma and measured airway resistance and serum inflammatory cell levels. Real-time polymerase chain reaction (RT-qPCR), Western blotting, and enzyme-linked immunosorbent assay (ELISA) analyses were used to assess gene and protein expression levels. Exosomes were isolated and characterized. RNA immunoprecipitation (RIP) and RNA pull-down assays were conducted to examine the interaction between hnRNPA2B1 and lnc-TRPM2-AS1. In the ovalbumin (OVA)-challenged mouse model, ephedrine treatment reduced inflammatory responses, airway resistance, and Th1/Th2 cell imbalance. Exosomes from OVA-treated AECs showed elevated levels of lnc-TRPM2-AS1, which were diminished following ephedrine treatment. The exosomal lnc-TRPM2-AS1 mediated the Th1/Th2 imbalance in CD4+ T cells, with its packaging into exosomes being facilitated by hnRNPA2B1. This study unveils a novel mechanism by which ephedrine ameliorates OVA-induced CD4+ T cell imbalance by suppressing AEC-derived exosomal lnc-TRPM2-AS1. These findings could provide a theoretical framework for using ephedrine in asthma treatment.

Identification of plasma protein markers of allergic disease risk: a mendelian randomization approach to proteomic analysis

BACKGROUND

While numerous allergy-related biomarkers and targeted treatment strategies have been developed and employed, there are still signifcant limitations and challenges in the early diagnosis and targeted treatment for allegic diseases. Our study aims to identify circulating proteins causally associated with allergic disease-related traits through Mendelian randomization (MR)-based analytical framework.

METHODS

Large-scale cis-MR was employed to estimate the effects of thousands of plasma proteins on five main allergic diseases. Additional analyses including MR Steiger analyzing and Bayesian colocalisation, were performed to test the robustness of the associations; These findings were further validated utilizing meta-analytical methods in the replication analysis. Both proteome- and transcriptome-wide association studies approach was applied, and then, a protein-protein interaction was conducted to examine the interplay between the identified proteins and the targets of existing medications.

RESULTS

Eleven plasma proteins were identified with links to atopic asthma (AA), atopic dermatitis (AD), and allergic rhinitis (AR). Subsequently, these proteins were classified into four distinct target groups, with a focus on tier 1 and 2 targets due to their higher potential to become drug targets. MR analysis and extra validation revealed STAT6 and TNFRSF6B to be Tier 1 and IL1RL2 and IL6R to be Tier 2 proteins with the potential for AA treatment. Two Tier 1 proteins, CRAT and TNFRSF6B, and five Tier 2 proteins, ERBB3, IL6R, MMP12, ICAM1, and IL1RL2, were linked to AD, and three Tier 2 proteins, MANF, STAT6, and TNFSF8, to AR.

CONCLUSION

Eleven Tier 1 and 2 protein targets that are promising drug target candidates were identified for AA, AD, and AR, which influence the development of allergic diseases and expose new diagnostic and therapeutic targets.

Novel insights into the anti-asthmatic effect of Raphanus sativus L. (Raphani Semen): Targeting immune cells, inflammatory pathways and oxidative stress markers

ETHNOPHARMACOLOGICAL RELEVANCE

Raphanus sativus L. is a well-known medicinal plant with traditional therapeutic applications in various common ailments including inflammation and asthma.

AIMS OF THE STUDY

This study aimed to evaluate the chemical composition and anti-asthmatic potential of the hydro-methanolic extract of the leaves of R. sativus L. (Rs.Cr) using various in vitro and in vivo investigations.

MATERIALS AND METHODS

The Rs.Cr was subjected to preliminary phytochemical analysis and HPLC profiling. The safety was assessed through oral acute toxicity tests in mice. The antiasthmatic effect of the extract was studied using milk-induced leukocytosis and ovalbumin (OVA)-induced allergic asthma models established in mice. While mast cell degranulation and passive paw anaphylaxis models were established in rats. Moreover, effect of the extract was studied on various oxidative and inflammatory makers. The antioxidant effect of the extract was also studied by in vitro DPPH method.

RESULTS

The HPLC profiling of Rs.Cr showed the presence of important polyphenols in a considerable quantity. In toxicity evaluation, Rs.Cr showed no sign of morbidity or mortality with LD50 < 2000 mg/kg. The extract revealed significant mast cell disruption in a dose-dependent manner compared to the intoxicated group. Similarly, treatment with Rs.Cr and dexamethasone significantly (p < 0.001) reduced paw edema volume. Subcutaneous injection of milk at a dose of 4 mL/kg, after 24 h of its administration, showed an increase in the leukocyte count in the intoxicated group. Similarly, mice treated with dexamethasone and Rs.Cr respectively showed a significant decrease in leukocytes and eosinophils count in the ovalbumin-induced allergic asthma model. The extract presented a significant (p˂0.001) alleviative effect on the levels of SOD and GSH, MDA, IL-4, IL-5, and IL-13 in a dose-dependent manner as compared to the intoxicated group. Furthermore, the histological evaluation also revealed a notable decrease in inflammatory and goblet cell count with reduced mucus production.

CONCLUSION

The current study highlights mechanism-based novel insights into the anti-asthmatic potential of R. sativus that also strongly supports its traditional use in asthma.

Gut-lung axis and asthma: A historical review on mechanism and future perspective

BACKGROUND

Gut microbiota are closely related to the development and regulation of the host immune system by regulating the maturation of immune cells and the resistance to pathogens, which affects the host immunity. Early use of antibiotics disrupts the homeostasis of gut microbiota and increases the risk of asthma. Gut microbiota actively interact with the host immune system via the gut-lung axis, a bidirectional communication pathway between the gut and lung. The manipulation of gut microbiota through probiotics, helminth therapy, and fecal microbiota transplantation (FMT) to combat asthma has become a hot research topic. BODY: This review mainly describes the current immune pathogenesis of asthma, gut microbiota and the role of the gut-lung axis in asthma. Moreover, the potential of manipulating the gut microbiota and its metabolites as a treatment strategy for asthma has been discussed.

CONCLUSION

The gut-lung axis has a bidirectional effect on asthma. Gut microecology imbalance contributes to asthma through bacterial structural components and metabolites. Asthma, in turn, can also cause intestinal damage through inflammation throughout the body. The manipulation of gut microbiota through probiotics, helminth therapy, and FMT can inform the treatment strategies for asthma by regulating the maturation of immune cells and the resistance to pathogens.

Aerobic physical training reduces severe asthma phenotype involving kinins pathway

INTRODUCTION

Aerobic physical training (APT) reduces eosinophilic airway inflammation, but its effects and mechanisms in severe asthma remain unknown.

METHODS

An in vitro study employing key cells involved in the pathogenesis of severe asthma, such as freshly isolated human eosinophils, neutrophils, and bronchial epithelial cell lineage (BEAS-2B) and lung fibroblasts (MRC-5 cells), was conducted. Additionally, an in vivo study using male C57Bl/6 mice, including Control (Co; n = 10), Trained (Exe; n = 10), house dust mite (HDM; n = 10), and HDM + Trained (HDM + Exe; n = 10) groups, was carried out, with APT performed at moderate intensity, 5x/week, for 4 weeks.

RESULTS

HDM and bradykinin, either alone or in combination, induced hyperactivation in human neutrophils, eosinophils, BEAS-2B, and MRC-5 cells. In contrast, IL-10, the primary anti-inflammatory molecule released during APT, inhibited these inflammatory effects, as evidenced by the suppression of numerous cytokines and reduced mRNA expression of the B1 receptor and ACE-2. The in vivo study demonstrated that APT decreased bronchoalveolar lavage levels of bradykinin, IL-1β, IL-4, IL-5, IL-17, IL-33, TNF-α, and IL-13, while increasing levels of IL-10, klotho, and IL-1RA. APT reduced the accumulation of polymorphonuclear cells, lymphocytes, and macrophages in the peribronchial space, as well as collagen fiber accumulation, epithelial thickness, and mucus accumulation. Furthermore, APT lowered the expression of the B1 receptor and ACE-2 in lung tissue and reduced bradykinin levels in the lung tissue homogenate compared to the HDM group. It also improved airway resistance, tissue resistance, and tissue damping. On a systemic level, APT reduced total leukocytes, eosinophils, neutrophils, basophils, lymphocytes, and monocytes in the blood, as well as plasma levels of IL-1β, IL-4, IL-5, IL-17, TNF-α, and IL-33, while elevating the levels of IL-10 and IL-1RA.

CONCLUSION

These findings indicate that APT inhibits the severe asthma phenotype by targeting kinin signaling.

Jiangqi Pingxiao formula regulates dendritic cell apoptosis in an autophagy-dependent manner through the AMPK/mTOR pathway in a murine model of OVA-induced asthma

ETHNOPHARMACOLOGICAL RELEVANCE

Allergic asthma is a recurring respiratory condition that typically manifests during childhood or adolescence. It is characterized by a dominant type II immune response triggered by the identification and capturing of inhaled allergens by dendritic cells (DCs). Jiangqi Pingxiao Formula (JQPXF), a prescription medicine used for the treatment of pediatric asthma, has been clinically proven to be both safe and effective. However, its mechanism of action in the treatment of asthma has not been fully been fully elucidated. Recent research suggests that several natural compounds have the potential to target dendritic cells (DCs) and alleviate ovalbumin (OVA)-induced asthma, which may also be found within JQPXF.

AIM OF THE STUDY

This study aimed to elucidate the effect of JQPXF on OVA-induced asthma model and its molecular mechanism targeting DCs.

MATERIALS AND METHODS

The main constituents of JQPXF were analyzed by ultra performance liquid chromatography (UPLC). An asthma model was established by OVA. Hematoxylin-eosin staining and measurement of respiratory function was used to evaluate the treatment effect of JQPXF on asthmatic mice. Cytokine (IL-5, IL-13 and IgE) concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Flow cytometry was employed to evaluate inflammatory cell infiltration (T helper 2 cells and DCs) in vivo and DC survival in vivo and vitro. Western blot and immunofluorescence were used to verify the molecular mechanisms.

RESULTS

The results suggest that JQPXF can ameliorate pathological conditions and improve lung function in asthmatic mice, as well as the Th2 cells. Treatment with JQPXF significantly reduced the number of DCs and increased the number of Propidium iodide+ (PI) DCs. Furthermore, JQPXF upregulated protein levels of the pro-apoptotic factors Cleaved-caspase-3 and Bax, while downregulating the anti-apoptotic factor Bcl-2. Simultaneously, JQPXF increased autophagy levels by facilitating p62 degradation and promoting translation from LC3B I to LC3B II of DCs in vitro, as well as reducing the integrated optical density (IOD) of p62 within the CD11c-positive area in the lung. 3-Methyladenine (3-MA) was used to block autophagic flux and the apoptotic effect of JQPXF on DCs was abolished in vitro, with the number of DCs decreased by JQPXF being reversed in vivo. We further investigated the upstream key regulator of autophagy, the AMPK/mTOR pathway, and found that JQPXF increased AMPK phosphorylation while decreasing mTOR phosphorylation levels. Additionally, we employed Compound C (CC) as an AMPK inhibitor to inhibit this signaling pathway, and our findings revealed that both autophagic flux and apoptotic levels in DCs were abolished in vitro.

CONCLUSIONS

In summary, we have demonstrated that JQPXF could alleviate type II inflammation in an asthmatic model by promoting the apoptosis of DCs through an autophagy-dependent mechanism, achieved by regulating the AMPK/mTOR signaling pathway.

MicroRNAs in chronic pediatric diseases (Review)

MicroRNAs are small non-coding RNAs with a length of 20-24 nucleotides. They bind to the 3'-untranslated region of target genes to induce the degradation of target mRNAs or inhibit their translation. Therefore, they are involved in the regulation of development, apoptosis, proliferation, differentiation and other biological processes (including hormone secretion, signaling and viral infections). Chronic diseases in children may be difficult to treat and are often associated with malnutrition resulting from a poor diet. Consequently, further complications, disease aggravation and increased treatment costs impose a burden on patients and their families. Existing evidence suggests that microRNAs are involved in various chronic non-neoplastic diseases in children. The present review discusses the roles of microRNAs in five major chronic diseases in children, namely, diabetes mellitus, congenital heart diseases, liver diseases, bronchial asthma and epilepsy, providing a theoretical basis for them to become therapeutic biomarkers in chronic pediatric diseases.

Transdermally delivered tolerogenic nanoparticles induced effective immune tolerance for asthma treatment

Induction of antigen-specific immune tolerance for the treatment of allergic or autoimmune diseases is an attractive strategy. Herein, we investigated the protective effect of a transdermal microneedle patch against allergic asthma by stimulating allergen-specific immune tolerance. We fabricated biodegradable tolerogenic nanoparticles (tNPs) that are loaded with a model allergen ovalbumin (OVA) and an immunomodulator rapamycin, and filled the tNPs into microneedle tips by centrifugation to form sustained-release microneedles. After intradermal immunization, the microneedles successfully delivered the cargos into the skin and sustainedly released them for over 96 h. Importantly, the microneedles induced allergen-specific regulatory T cells (Treg), decreased the levels of pro-inflammatory cytokines and antibodies while increased anti-inflammation cytokines, finally leading to restored immune homeostasis. The lung tissue analysis illustrated that the sustained-release microneedles significantly reduced the infiltration of eosinophils, decreased the accumulation of mucus and collagen, and significantly relived asthma symptoms. Our results suggested that the sustained-release microneedle-based transdermal delivery system can induce antigen-specific immune tolerance with improved compliance and efficacy, providing a new therapeutic strategy for the treatment of allergic and autoimmune diseases.

Platycoside E alleviates allergic airway inflammation in obesity-related asthma mouse model

BACKGROUND

Overweight and obesity are related to an increased risk of asthma. The effect of platycoside E (PE) on obesity-related asthma remains unknown.

METHODS

To mimic obesity-related asthma conditions in vivo, C57BL/6 mice were exposed to a high-fat diet (HFD) and challenged with ovalbumin (OVA). PE was administrated intraperitoneally during the OVA treatment. Body weight was measured at 8th week before PE treatment and after sacrificing the mice. Airway inflammation and airway hyperresponsiveness (AHR) were evaluated. Immunohistochemistry staining was performed to evaluate eosinophils. Histopathological changes were determined by HE staining. Cellular model of asthma was established using IL-13 in BEAS-2B cells. Levels of proinflammatory cytokines and oxidative stress indicators were measured by ELISA kits and commercial kits, respectively. Cell viability was detected by CCK-8 assays.

RESULTS

IL-13 treatment led to inflammatory and oxidative damage in bronchial epithelial cells, which was relieved by PE. PE administration significantly reduced HFD-induced obesity and relieved AHR and airway inflammation in obese asthmatic mice. The expression of proinflammatory cytokines in BALF and lung tissues in obese asthmatic mice were reduced by PE. PE administration also reduced infiltration of eosinophils and inflammation scores in obese asthmatic mice.

CONCLUSION

PE suppresses airway inflammation and AHR in obese asthmatic mice and serves as an effective option for treating obesity-related asthma.

Altered Fear Behavior in Aeroallergen House Dust Mite Exposed C57Bl/6 Mice: A Model of Th2-skewed Airway Inflammation

There is a growing interest for studying the impact of chronic inflammation, particularly lung inflammation, on the brain and behavior. This includes asthma, a chronic inflammatory condition, that has been associated with psychiatric conditions such as posttraumatic stress disorder (PTSD). Although asthma is driven by elevated production of Th2 cytokines (IL-4, IL-5 and IL-13), which drive asthma symptomology, recent work demonstrates that concomitant Th1 or Th17 cytokine production can worsen asthma severity. We previously demonstrated a detrimental link between PTSD-relevant fear behavior and allergen-induced lung inflammation associated with a mixed Th2/Th17-inflammatory profile in mice. However, the behavioral effects of Th2-skewed airway inflammation, typical to mild/moderate asthma, are unknown. Therefore, we investigated fear conditioning/extinction in allergen house dust mite (HDM)-exposed C57Bl/6 mice, a model of Th2-skewed allergic asthma. Behaviors relevant to panic, anxiety, and depression were also assessed. Furthermore, we investigated the accumulation of Th2/Th17-cytokine-expressing cells in lung and brain, and the neuronal activation marker, ΔFosB, in fear regulatory brain areas. HDM-exposed mice elicited lower freezing during fear extinction with no effects on acquisition and conditioned fear. No HDM effect on panic, anxiety or depression-relevant behaviors was observed. While HDM evoked a Th2-skewed immune response in lung tissue, no significant alterations in brain Th cell subsets were observed. Significantly reduced ΔFosB+ cells in the basolateral amygdala of HDM mice were observed post extinction. Our data indicate that allergen-driven Th2-skewed responses may induce fear extinction promoting effects, highlighting beneficial interactions of Th2-associated immune mediators with fear regulatory circuits.

Shared genetic architecture of blood eosinophil counts and asthma in UK Biobank

Rationale

Asthma is a complex, heterogeneous disease strongly associated with type 2 inflammation, and blood eosinophil counts guide therapeutic interventions in moderate and severe asthma. Eosinophils are leukocytes involved in type 2 immune responses. Despite these critical associations between asthma and blood eosinophil counts, the shared genetic architecture of these two traits remains unknown. The objective of the present study was to characterise the genetic architecture of blood eosinophil counts and asthma in the UK Biobank.

Methods

We performed genome-wide association studies (GWAS) of doctor-diagnosed asthma, blood eosinophil, neutrophil, lymphocyte and monocyte counts in the UK Biobank. Genetic correlation analysis was performed on GWAS results and validated in the Trans-National Asthma Genetic Consortium (TAGC) study of asthma.

Results

GWAS of doctor-diagnosed asthma and blood eosinophil counts in the UK Biobank identified 585 and 3429 significant variants, respectively. STAT6, a transcription factor involved in interleukin-4 signalling, was a key shared pathway between asthma and blood eosinophil counts. Genetic correlation analysis demonstrated a positive correlation between doctor-diagnosed asthma and blood eosinophil counts (r=0.38±0.10, correlation±se; p=4.7×10-11). As a validation of this association, we found a similar correlation between TAGC and blood eosinophil counts in the UK Biobank (0.37±0.08, correlation±se; p=1.2×10-6).

Conclusions

These findings define the shared genetic architecture between blood eosinophil counts and asthma risk in subjects of European ancestry and point to a genetic link to the STAT6 signalling pathway in these two traits.

β2-adrenergic receptor agonist corrects immune thrombocytopenia by reestablishing the homeostasis of T cell differentiation

BACKGROUND

The sympathetic nerve is known to regulate immune responses in autoimmunity. Aberrant T cell immunity plays a vital role in immune thrombocytopenia (ITP) pathogenesis. The spleen is the primary site of platelet destruction. However, little is known whether and how splenic sympathetic innervation and neuroimmune modulation contribute to ITP pathogenesis.

OBJECTIVES

To determine the sympathetic distribution in the spleen of ITP mice and the association between splenic sympathetic nerves and T cell immunity in ITP development, and to evaluate the treatment potential of β2-adrenergic receptor (β2-AR) in ITP.

METHODS

Chemical sympathectomy was performed in an ITP mouse model with 6-hydroxydopamine and treated with β2-AR agonists to evaluate the effects of sympathetic denervation and activation.

RESULTS

Decreased sympathetic innervation in the spleen of ITP mice was observed. Significantly increased percentages of Th1 and Tc1 cells and reduced percentages of regulatory T cells (Tregs) were also observed in ITP mice with chemical sympathectomy (ITP-syx mice) relative to mice without sympathectomy (controls). Expression of genes associated with Th1, including IFN-γ and IRF8, was significantly upregulated, whereas genes associated with Tregs, including Foxp3 and CTLA4, were significantly downregulated in ITP-syx mice compared with controls. Furthermore, β2-AR restored the percentage of Tregs and increased platelet counts at days 7 and 14 in ITP mice.

CONCLUSION

Our findings indicate that decreased sympathetic distribution contributes to ITP pathogenesis by disturbing the homeostasis of T cells and that β2-AR agonists have potential as a novel treatment for ITP.

Multiplex Proteomic Evaluation in Inborn Errors with Deregulated IgE Response

(1) Background: Atopic dermatitis constitutes one of the most common inflammatory skin manifestations of the pediatric population. The onset of many inborn errors occurs early in life with an AD-like picture associated with a deregulated IgE response. The availability of proteomic tests for the simultaneous evaluation of hundreds of molecules allows for more precise diagnosis in these cases. (2) Methods: Comparative genomic hybridization microarray (Array-CGH) analysis and specific IgE evaluation by using allergenic microarray (ISAC) and microarray (ALEX2) systems were performed. (3) Results: Proteomic investigations that use multiplex methods have proven to be extremely useful to diagnose the sensitization profile in inborn errors with deregulated IgE synthesis. Four patients with rare diseases, such as recessive X-linked ichthyosis (RXLI, OMIM 308100), Comel-Netherton syndrome (NS, OMIM256500), monosomy 1p36 syndrome (OMIM: 607872), and a microduplication of Xp11.4 associated with extremely high levels of IgE: 7.710 kU/L, 5.300 kU/L, 1.826 kU/L, and 10.430 kU/L, respectively, were evaluated by micro- and macroarray multiplex methods. Polyreactivity to both environmental and food allergens was observed in all cases, including the first described case of association of X-chromosome microduplication and HIE. (4) Conclusions: Extensive use of proteomic diagnostics should be included among the procedures to be implemented in inborn errors with hyper-IgE.

The Role of Staphylococcus aureus and Its Toxins in the Pathogenesis of Allergic Asthma

Bronchial asthma is one of the most common chronic diseases worldwide and affects more than 300 million patients. Allergic asthma affects the majority of asthmatic children as well as approximately 50% of adult asthmatics. It is characterized by a Th2-mediated immune response against aeroallergens. Many aspects of the overall pathophysiology are known, while the underlying mechanisms and predisposing factors remain largely elusive today. Over the last decade, respiratory colonization with Staphylococcus aureus (S. aureus), a Gram-positive facultative bacterial pathogen, came into focus as a risk factor for the development of atopic respiratory diseases. More than 30% of the world’s population is constantly colonized with S. aureus in their nasopharynx. This colonization is mostly asymptomatic, but in immunocompromised patients, it can lead to serious complications including pneumonia, sepsis, or even death. S. aureus is known for its ability to produce a wide range of proteins including toxins, serine-protease-like proteins, and protein A. In this review, we provide an overview of the current knowledge about the pathophysiology of allergic asthma and to what extent it can be affected by different toxins produced by S. aureus. Intensifying this knowledge might lead to new preventive strategies for atopic respiratory diseases.

Increased Hippocampal Glucocorticoid Receptor Expression and Reduced Anxiety-Like Behavior Following Tuina in a Rat Model With Allergic Airway Inflammation

OBJECTIVE

This study aimed to explore the influence mechanism of Tuina on anxiety-like behavior in immature rats with allergic airway inflammation (AAI).

METHODS

A total of 27 Sprague-Dawley male rats (aged ∼5 weeks) were divided randomly into control, AAI, and AAI with Tuina groups (9 rats per group). The anxiety-like behavior was assessed by an open field test and elevated plus-maze test. Allergic airway inflammation was assessed based on the pathological score of the lung, plasma ovalbumin-specific immunoglobulin E, interleukin 4, interleukin 5, and tumor necrosis factor-alpha levels. Glucocorticoid receptor (GR) messenger RNA and protein expression in the hippocampus and lung were detected by polymerase chain reaction and immunohistochemistry, respectively. Meanwhile, corticotropin-releasing hormone (CRH) messenger RNA in the hypothalamus, the plasma levels of adrenocorticotropic hormone and corticosterone were also determined respectively by polymerase chain reaction and enzyme-linked immunosorbent assay for hypothalamic-pituitary-adrenal axis (HPA) function.

RESULTS

The AAI group had obvious anxiety-like behavior and hyperactive HPA axis, along with decreased GR expression in the hippocampus and lung. Following Tuina, AAI and the anxiety-like behavior were efficiently reduced, and the hyperactivity of HPA axis was efficiently inhibited, along with enhanced GR expression in the hippocampus and lung.

CONCLUSION

Glucocorticoid receptor expression in the hippocampus and lung was enhanced, and anxiety-like behavior was reduced following Tuina in rats with AAI.

Cytokine-polymorphisms associated with Preeclampsia: A review

BACKGROUND

Preeclampsia (PE) is a syndromic disorder that affects 2% to 8% of pregnancies and is diagnosed principally when hypertension appears in the second-d half of pregnancy. WHO estimates the incidence of PE to be seven times higher in developing countries than in developed countries. Severe preeclampsia/eclampsia is one of the most important causes of maternal mortality, associated with 50,000 to 100,000 annual deaths globally as well as serious fetal and neonatal morbidity and mortality, especially in developing countries. Even though evidence from family-based studies suggest PE has a heritable component, its etiology, and specific genetic contributions remain unclear. Many studies examining the genetic factors contributing to PE have been conducted, most of them are focused on single nucleotide polymorphisms (SNPs). Given that PE has a very important inflammatory component, is mandatory to examine cytokine-SNPs for elucidating all mechanisms involved in this pathology. In this review, we describe the most important cytokine-polymorphisms associated with the onset and development of PE. We aim to provide current and relevant evidence in this regard.

METHODS

We searched English databases such as PubMed and the National Center for Biotechnology Information. The publication time of the papers was set from the establishment of the databases to February 2022. All studies about Th1/Th2/Th17 cytokines polymorphisms were included in our study.

RESULTS

SNPs in IFN-γ, TNF-α, IL-4, IL-6, IL-10, IL-17A, and IL-22 are associated with the development, early-onset and severity of PE, being the Th1/Th2/Th17 responses affected by the presence of these SNPs.

CONCLUSIONS

The changes in Th1/Th2/Th17 response modify processes such as placentation, control of inflammation, and vascular function. Nonetheless, association studies have shown different results depending on sample size, diagnostic, and population.

Immune mechanisms induced by sublingual immunotherapy in allergic respiratory diseases

Allergic respiratory diseases (ARDs) are still a major burden on global public health. Sublingual immunotherapy (SLIT) is a mode of allergen immunotherapy (AIT) which involves administration of the allergen under the tongue, and benefits from tolerogenic properties of the oral mucosa. Studies revealed reduced levels of eosinophilia and eosinophil-dominated inflammation in airways of both animals and humans after SLIT. SLIT was also suggested to lower basophil responsiveness and innate lymphoid cell-2 function in blood samples collected from patients with ARD. Moreover, apart from shifting pathogenic type 2 (TH2) to a type 1 (TH1) and protective regulatory (Treg) polarization of helper T-cell immune response, antibody isotype switch from IgE to IgG1, IgG2, IgG4 and IgA was also reported in patients with ARD receiving SLIT. Today, the literature on SLIT-mediated activities is still scarce and more studies are required to further enlighten the mechanisms utilized by SLIT for the induction of tolerance. The aim of this review is to summarize the current knowledge about the immune-regulatory mechanisms induced by SLIT against ARDs.

Sanzi Yangqin Decoction Alleviates Allergic Asthma by Modulating Th1/Th2 Balance: Coupling Network Pharmacology with Biochemical Pharmacology

This study aimed to verify that Sanzi Yangqin Decoction (SYD) can relieve asthma in mice and explore the effect on TH1/Th2 balance. The targets of SYD and asthma were explored from the public database using various methods. The potential targets and signaling pathways were identified by KEGG enrichment analysis from DAVID database. Mice asthma models were established using OVA and aluminum hydroxide. Lung tissues of mice were stained with HE and Masson. The contents of IFN-γ, IL-4, and TNF-α in BALF and IgE in mouse serum were detected using ELISA. In addition, the changes in Th1 and Th2 cells of the spleen were detected by flow cytometry. Fourteen core targets including IL4, IFNG, and MMP9 were identified for the treatment of asthma by SYD. The content of IL-4 in the lung tissue and BALF was gradually decreased with the increase in SYD concentration, while the IFN-γ was gradually increased. The drug significantly reduced IgE levels in serum and TNF-α in BALF. The number of Th1 cells in the spleen increased, while Th2 cells decreased in a concentration-dependent manner. SYD can alleviate pulmonary inflammation, restore Th1/Th2 balance, and relieve asthma.

Transgenic overexpression of α7 integrin in smooth muscle attenuates allergen‐induced airway inflammation in a murine model of asthma

Asthma is a chronic inflammatory disorder of the lower airways characterized by modulation of airway smooth muscle (ASM) function. Infiltration of smooth muscle by inflammatory mediators is partially regulated by transmembrane integrins and the major smooth muscle laminin receptor α7β1 integrin plays a critical role in the maintenance of ASM phenotype. The goal of the current study was to investigate the role of α7 integrin in asthma using smooth muscle‐specific α7 integrin transgenic mice (TgSM‐Itgα7) using both acute and chronic OVA sensitization and challenge protocols that mimic mild to severe asthmatic phenotypes. Transgenic over‐expression of the α7 integrin in smooth muscle resulted in a significant decrease in airway resistance relative to controls, reduced the total number of inflammatory cells and substantially inhibited the production of crucial Th2 and Th17 cytokines in airways. This was accompanied by decreased secretion of various inflammatory chemokines such as eotaxin/CCL11, KC/CXCL3, MCP‐1/CCL2, and MIP‐1β/CCL4. Additionally, α7 integrin overexpression significantly decreased ERK1/2 phosphorylation in the lungs of TgSM‐Itgα7 mice and affected proliferative, contractile, and inflammatory downstream effectors of ERK1/2 that drive smooth muscle phenotype in the lung. Taken together, these results support the hypothesis that enhanced expression of α7 integrin in vivo inhibits allergic inflammation and airway resistance. Moreover, we identify ERK1/2 as a potential target by which α7 integrin signals to regulate airway inflammation. We conclude that identification of therapeutics targeting an increase in smooth muscle α7 integrin expression could serve as a potential novel treatment for asthma.

Isoorientin ameliorates OVA-induced asthma in a murine model of asthma

Allergic asthma which is induced by ovalbumin (OVA) is a chronic airway inflammation disease. Isoorientin (Iso) is a natural C-glucosyl flavone with many biological properties. We aimed to evaluate the effectiveness of Iso on OVA-induced allergic asthma. A total of 30 C57BL/6 mice were randomly divided into five groups: control group, OVA group, Dex (dexamethasone, 10 mg/kg) group, low-dose Iso group (Iso-L, 25 mg/kg), and high-dose Iso group (Iso-H, 50 mg/kg). The serum and bronchoalveolar lavage fluid (BALF) were collected for biochemical parameters, the lung tissue was collected for hematoxylin-eosin (H&E) staining, immunohistochemistry (IHC), and western blot. The levels of IL-4, IL-5, IL-13, malondialdehyde (MDA), NO, and reactive oxygen species (ROS) in Iso-L and Iso-H groups were significantly lower than that in model group (p < 0.05). Simultaneously, the levels of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity were higher than that in model group (p < 0.05). Iso significantly ameliorated airway hyperresponsiveness. Meanwhile, H&E staining revealed that mice treated with Iso resulted in the ameliorated inflammatory cell infiltration and a reduction in interstitial thickening. The nuclear factor erythroid 2-like 2 (Nrf2) and HO-1 protein expression in Iso-L and Iso-H groups were enhanced over that in model group, while p-NF-κB-p65 and p-IκB-α protein expression was decreased (p < 0.05). Our research indicated that Iso alleviated the OVA-induced allergic asthma, and this effect can be explained by the modulation of Nrf2/HO-1 and NF-κB signaling pathway; thus, the results providing a therapeutic rationale for the treatment of Iso on allergic asthma.

KCa3.1 differentially regulates trachea and bronchi epithelial gene expression in a chronic-asthma mouse model

Ion channels are potentially exploitable as pharmacological targets to treat asthma. This study evaluated the role of KCa3.1 channels, encoded by Kcnn4, in regulating the gene expression of mouse airway epithelium and the development of asthma traits. We used the ovalbumin (OVA) challenge as an asthma model in wild type and Kcnn4^-/- mice, performed histological analysis, and measured serum IgE to evaluate asthma traits. We analyzed gene expression of isolated epithelial cells of trachea or bronchi using mRNA sequencing and gene ontology and performed Ussing chamber experiments in mouse trachea to evaluate anion secretion. Gene expression of epithelial cells from mouse airways differed between trachea and bronchi, indicating regional differences in the inflammatory and transepithelial transport properties of proximal and distal airways. We found that Kcnn4 silencing reduced mast cell numbers, mucus, and collagen in the airways, and reduced the amount of epithelial anion secretion in the OVA-challenged animals. Additionally, gene expression was differentially modified in the trachea and bronchi, with Kcnn4 genetic silencing significantly altering the expression of genes involved in the TNF pathway, supporting the potential of KCa3.1 as a therapeutic target for asthma.

Sigma-1 Receptor Alleviates Airway Inflammation and Airway Remodeling Through AMPK/CXCR4 Signal Pathway

Sigma non-opioid intracellular receptor 1 (Sigma-1R) has been proven to play a major role in inflammation and structural remodeling. However, its role in airway inflammation and airway remodeling remains unclear. The purpose of this study aimed to explore the role and mechanism of Sigma-1R in airway remodeling and epithelial-mesenchymal transition (EMT) process in vivo and in vitro. We observed the decrease of Sigma-1R in lung tissue of asthma model. In the mouse model of allergic airway inflammation (AAI), Sigma-1R agonist RPE-084 significantly relieved airway inflammation and airway remodeling, while Sigma-1R antagonist BD1047 (B8562) had opposite effects. Further research showed that RPE-084 treatment increased the expression of pAMPK and inhibited the expression of CXCR4. Furthermore, RPE-084 treatment suppressed the levels of IL-4, IL-5, and IL-13 in BALF. We found that RPE-084 or Sigma-1R overexpression vector treatment regulated cell cycle and inhibited cell proliferation, migration, and EMT process in TGF-β1-induced 16HBE cells. Finally, we confirmed that AMP-activated protein kinase (AMPK) inhibitor compound C or CXCR4 agonist ATI-2341 both reversed the effects of Sigma-1R on TGF-β1-induced 16 HBE cells. In a word, our research shows that Sigma-1R is helpful to improve airway remodeling of asthma, and emphasizes a new candidate molecular for asthma treatment.

Clinical features and nasal inflammation in asthma and allergic rhinitis

Asthma and allergic rhinitis (AR) are widely considered to be the most common chronic inflammatory disorders. This study was performed to investigate the clinical features, disease severity, and upper airway inflammation among patients with asthma, AR, and asthma comorbid AR. Blood and nasal lavage fluid samples were collected from patients with isolated asthma (n = 23), isolated AR (n = 22), and asthma comorbid AR (n = 22). Demographic data, symptom evaluation, and spirometry were obtained from all subjects. The levels of interleukin (IL)-4, IL-5, IL-13, IL-17, IL-25, IL-33, and S100 proteins were measured in the nasal lavage fluid. Compared with isolated asthma, patients with asthma comorbid AR showed a lower quality of life according to the asthma quality-of-life questionnaire (AQLQ) score (6.11 ± 0.47 vs. 6.45 ± 0.35, P = 0.007). Additionally, no significant difference in the levels of IL-4 (P = 0.116), IL-25 (P = 0.235), and S100A12 (P = 0.392) was observed in nasal lavage fluid among three groups. However, miniscule levels of IL-5, IL-17, IL-13, IL-33, S100A8, and S100A9 were detected in nasal lavage fluid in all three groups. Patients with asthma comorbid AR showed an increased level of systemic cytokine in plasma than that of patients with isolated AR or asthma alone. The finding from our study may help clinicians to better understand the airway inflammation among asthma patients with or without AR.

Glucose-Restricted Diet Regulates the Tumor Immune Microenvironment and Prevents Tumor Growth in Lung Adenocarcinoma

Background

Lung cancer is the second common cancer type in western countries and has a high mortality. During the development and progression of the tumor, the nutrients in its environment play a central role. The tumor cells depend crucially on glucose metabolism and uptake. Tumor cell metabolism is dominated by the Warburg effect, where tumor cells produce large amounts of lactate from pyruvate under aerobic conditions. We thus reasoned that, reducing carbohydrates in the diet might support anti-tumoral effects of current immunotherapy and additionally target tumor immune escape.

Objectives

The link between reducing carbohydrates to improve current immunotherapy is not clear. We thus aimed at analyzing the effects of different glucose levels on the tumor development, progression and the anti-tumoral immune response.

Methods

We correlated the clinical parameters of our LUAD cohort with different metabolic markers. Additionally, we performed cell culture experiments with A549 tumor cell line under different glucose levels. Lastly, we investigated the effect of low and high carbohydrate diet in an experimental murine model of lung cancer on the tumor progression and different immune subsets.

Results

Here we found a positive correlation between the body mass index (BMI), blood glucose levels, reduced overall survival (OS) and the expression of Insulin-like growth factor-1 receptor (IGF1R) in the lung tumoral region of patients with lung adenocarcinoma (LUAD). Furthermore, increasing extracellular glucose induced IGF1R expression in A549 LUAD cells. Functional studies in a murine model of LUAD demonstrated that, glucose restricted diet resulted in decreased tumor load in vivo. This finding was associated with increased presence of lung infiltrating cytotoxic CD8+ T effector memory (TEM), tissue resident memory T (TRM) and natural killer cells as well as reduced IGFR mRNA expression, suggesting that glucose restriction regulates lung immunity in the tumor microenvironment.

Conclusions

These results indicate that, glucose restricted diet improves lung immune responses of the host and suppresses tumor growth in experimental lung adenocarcinoma. As glucose levels in LUAD patients were negatively correlated to postoperative survival rates, glucose-restricted diet emerges as therapeutic avenue for patients with LUAD.

Meteorin-β/Meteorin like/IL-41 attenuates airway inflammation in house dust mite-induced allergic asthma

We sought to examine the regulatory effect of Meteorin-β (Metrnβ)/Meteorin like (Metrnl)/IL-41 on lung inflammation in allergic asthma. We found that Metrnβ was elevated significantly in asthmatic patients and in mice with allergic asthma induced by house dust mite (HDM) extract. Upon exposure to HDM, Metrnβ was secreted predominantly by airway epithelial cells and inflammatory cells, including macrophages and eosinophils. The increased Metrnβ effectively blocked the development of airway hyperreactivity (AHR) and decreased inflammatory cell airway infiltration and type 2 cytokine production, which was associated with downregulated DC-mediated adaptive immune responses. Moreover, Metrnβ impaired the maturation and function of bone marrow-derived dendritic cells in vitro. Asthmatic mice adoptively transferred with dendritic cells isolated from Metrnβ-treated allergic mice displayed decreased AHR, airway inflammation, and lung injury. Metrnβ also displayed anti-inflammatory properties in immunodeficient SCID mice with allergic asthma and in in vitro 3D ALI airway models. Moreover, blockade of Metrnβ by anti-Metrnβ antibody treatment promoted the development of allergic asthma. These results revealed the unappreciated protective roles of Metrnβ in alleviating DC-mediated Th2 inflammation in allergic asthma, providing the novel treatment strategy of therapeutic targeting of Metrnβ in allergic asthma.

Adenosine restrains ILC2-driven allergic airway inflammation via A2A receptor

Although group 2 Innate Lymphoid Cells (ILC2s) play important roles in driving the pathogenesis of allergic airway inflammation, the molecular mechanisms regulating ILC2 responses remain to be fully elucidated. Adenosine signaling is emerging as an important factor to limit excessive inflammation and tissue damage, its role in ILC2-driven airway inflammation remains to be understood. Here we identify adenosine as a negative regulator of ILC2s and allergic airway inflammation. Elevation of adenosine was observed in lungs after protease papain challenge. Adenosine receptor A2A was abundantly expressed in lung ILC2s. The adenosine analog NECA significantly suppress ILC2s responses and relieved airway inflammation induced by IL-33 or papain. Conversely, blockage of adenosine synthesis by CD73 inhibitor APCP or deficiency of A2A aggravated murine airway inflammation. Adoptive transfer of ILC2s into immunodeficiency NCG mice demonstrated that the regulation of ILC2 by adenosine was cell intrinsic. Mechanistic studies showed that the effects of adenosine on ILC2s were associated with changes in transcriptional profiling, and the elevation of intracellular cAMP and resulted NF-κB downregulation. These observations indicate that adenosine-A2A signaling is a negative regulator of ILC2s, which confers protection against airway inflammation and represents a novel therapeutic target for controlling asthma.

TH17 cells and corticosteroid insensitivity in severe asthma

Asthma is classically described as having either a type 2 (T2) eosinophilic phenotype or a non-T2 neutrophilic phenotype. T2 asthma usually responds to classical bronchodilation therapy and corticosteroid treatment. Non-T2 neutrophilic asthma is often more severe. Patients with non-T2 asthma or late-onset T2 asthma show poor response to the currently available anti-inflammatory therapies. These therapeutic failures result in increased morbidity and cost associated with asthma and pose a major health care problem. Recent evidence suggests that some non-T2 asthma is associated with elevated T_H17 cell immune responses. T_H17 cells producing Il-17A and IL-17F are involved in the neutrophilic inflammation and airway remodeling processes in severe asthma and have been suggested to contribute to the development of subsets of corticosteroid-insensitive asthma. This review explores the pathologic role of T_H17 cells in corticosteroid insensitivity of severe asthma and potential targets to treat this endotype of asthma.

Exacerbation of allergic asthma by somatic antigen of Echinococcus granulosus in allergic airway inflammation in BALB/c mice

BACKGROUND

There is ample evidence demonstrating a reverse relationship between helminth infection and immune-mediated diseases. Accordingly, several studies have shown that Echinococcus granulosus infection and hydatid cyst compounds are able to suppress immune responses in allergic airway inflammation. Previous studies have documented the ability of hydatid cysts to suppress aberrant Th2 immune response in a mouse model of allergic asthma. However, there is a paucity of research on the effects of protoscoleces on allergic asthma. Thus, this study was designed to evaluate the effects of somatic antigens of protoscoleces in a murine model of allergic airway inflammation.

METHODS

Ovalbumin (OVA)/aluminum hydroxide (alum) was injected intraperitoneally to sensitize BALB/c mice over a period of 0 to 7 days, followed by challenge with 1% OVA. The treatment group received somatic antigens of protoscoleces emulsified with PBS on these days in each sensitization before being challenged with 1% OVA on days 14, 15, and 16. The effects of somatic antigens of protoscoleces on allergic airway inflammation were evaluated by examining histopathological changes, the recruitment of inflammatory cells in the bronchoalveolar lavage, cytokine production in the homogenized lung tissue (IL-4, IL-5, IL-10, IL-17, and IFN-γ), and total antioxidant capacity in serum.

RESULTS

Overall, administration of somatic antigens of protoscoleces exacerbated allergic airway inflammation via increased Th2 cytokine levels in the lung homogenate, recruitment of eosinophils into bronchoalveolar lavage fluid, and pathological changes. In addition, total antioxidant capacity and IFN-γ levels declined following the administration of somatic antigens.

CONCLUSIONS

The results revealed that the co-administration of somatic products of protoscoleces with OVA/alum contributed to the exacerbation of allergic airway inflammation in BALB/c mice. Currently, the main cause of allergic-type inflammation exacerbation is unknown, and further research is needed to understand the mechanism of these interactions.

Emerging Roles of Non-Coding RNAs in Childhood Asthma

Asthma is a chronic airway inflammatory disease in children characterized by airway inflammation, airway hyperresponsiveness and airway remodeling. Childhood asthma is usually associated with allergy and atopy, unlike adult asthma, which is commonly associated with obesity, smoking, etc. The pathogenesis and diagnosis of childhood asthma also remains more challenging than adult asthma, such as many diseases showing similar symptoms may coexist and be confused with asthma. In terms of the treatment, although most childhood asthma can potentially be self-managed and controlled with drugs, approximately 5-10% of children suffer from severe uncontrolled asthma, which carries significant health and socioeconomic burdens. Therefore, it is necessary to explore the pathogenesis of childhood asthma from a new perspective. Studies have revealed that non-coding RNAs (ncRNAs) are involved in the regulation of respiratory diseases. In addition, altered expression of ncRNAs in blood, and in condensate of sputum or exhalation affects the progression of asthma via regulating immune response. In this review, we outline the regulation and pathogenesis of asthma and summarize the role of ncRNAs in childhood asthma. We also hold promise that ncRNAs may be used for the development of biomarkers and support a new therapeutic strategy for childhood asthma.

Activation of STAT6 by intranasal allergens correlated with the development of eosinophilic chronic rhinosinusitis in a mouse model

Eosinophilic chronic rhinosinusitis (ECRS) is a chronic inflammatory disease characterized by prominent eosinophilic infiltration along with a T-helper-2 (Th2) response. It has been well documented that signal transducer and activator of transcription 6 (STAT6) is a nuclear transcription factor that mediates Th2-type immunity and is implicatory of STAT1 and STAT3 in the pathogenesis of allergic airway diseases. However, little is known about the association between STATs and ECRS. Here, we explored the relationship between STAT1, STAT3, and/or STAT6 and eosinophilic inflammation accompanied by Th2-type immunity in a mouse model of ECRS. An ovalbumin (OVA)-staphylococcal enterotoxin B (SEB)-induced ECRS murine model was first established. The mucosal histological alterations were determined using hematoxylin and eosin staining. The number of eosinophils in peripheral blood was measured using a blood cell analyzer. The cytokine (IL-4, IL-5, IL17 A and IFN-γ) expression levels in the sinonasal mucosa and total and OVA-specific IgE from serum were measured using ELISA. Then, the protein levels of STAT1, STAT3, STAT6, phosphorylated STAT1 (p-STAT1), p-STAT3, p-STAT6, T-box expressed in T-cells (T-bet), GATA binding protein 3 (GATA-3), and retinoic acid receptor-related orphan receptor γ (RORγt) in the sinonasal mucosa were examined by immunohistochemical staining or Western blotting. Local administration of OVA combined with SEB (OVA + SEB) induced multiple polyp-like lesions, accompanied by prominent eosinophilic infiltration in the sinonasal mucosa. The OVA- and OVA+SEB-treated groups showed significantly higher eosinophil counts from peripheral blood and total and OVA-specific IgE levels from serum than those in the PBS- and SEB-treated groups. The levels of p-STAT6 were markedly increased by OVA + SEB exposure, as well as GATA-3, IL-4, and IL-5, but did not affect STAT6, p-STAT1, p-STAT3, T-bet, RORγt, IFN-γ, or IL-17A. Furthermore, an eosinophil count in the sinonasal mucosa showed a positive correlation with the level of p-STAT6 in the ECRS mouse model. Signal transducer and activator of transcription 6 signaling could be activated in the OVA+SEB-induced ECRS model and might be a crucial signal transducer in the development of Th2-skewed ECRS.

C-Kit+ cells can modulate asthmatic condition via differentiation into pneumocyte-like cells and alteration of inflammatory responses via ERK/NF-ƙB pathway

Objectives

The exact role of the progenitor cell types in the dynamic healing of asthmatic lungs is lacking. This investigation was proposed to evaluate the effect of intratracheally administered rat bone marrow-derived c-kit⁺ cells on ovalbumin-induced sensitized male rats.

Materials and Methods

Forty rats were randomly divided into 4 groups; healthy rats received phosphate-buffered saline (PBS) (C); sensitized rats received PBS (S); PBS containing C-kit- cells (S+C-kit^-); and PBS containing C-kit⁺ cells (S+C-kit⁺). After two weeks, circulatory CD4⁺/CD8⁺ T-cell counts and pulmonary ERK/NF-ƙB signaling pathway as well as the probability of cellular differentiation were assessed.

Results

The results showed that transplanted C-Kit⁺ cells were engrafted into pulmonary tissue and differentiated into epithelial cells. C-Kit⁺ cells could increase the number of CD4⁺ cells in comparison with the S group (P<0.001); however, they diminished the level of CD8⁺ cells (P<0.01). Moreover, data demonstrated increased p-ERK/ERK ratio (P<0.001) and NF-ƙB level (P<0.05) in sensitized rats compared with the C group. The administration of C-kit⁺, but not C-Kit^-, decreased p-ERK/ERK ratio and NF-ƙB level compared with those of the S group (P<0.05).

Conclusion

The study revealed that C-Kit⁺ cells engrafted into pulmonary tissue reduced the NF-ƙB protein level and diminished p-ERK/ERK ratio, leading to suppression of inflammatory response in asthmatic lungs.

Bee Venom Prevents Mucin 5AC Production through Inhibition of AKT and SPDEF Activation in Airway Epithelia Cells

IL-13 induces mucus metaplasia, which causes airway obstruction in asthma. Bee venom (BV) and its components have shown anti-inflammatory effects in allergic diseases such as atopic dermatitis and asthma. In this study, we investigated the effect of BV on IL-13-induced mucus metaplasia through activation of the signal transducer and activator of transcription (STAT6), and regulation of SAM-pointed domain containing Ets-like factor (SPDEF) and forkhead box A2 (FOXA2) in the airway epithelia cell line A549. In A549 cells, BV (1.0 µg/mL) inhibited IL-13 (10 ng/mL)-induced AKT phosphorylation, increase in SPDEF protein expression, and decrease in FOXA2 protein expression—but not STAT6 phosphorylation. BV also prevented the IL-13-induced increase in mucin 5AC (MUC5AC) mRNA and protein expression. Moreover, we observed that inhibition of phosphoinositide 3 kinase (PI3K)/AKT using LY294002 (50 µM) could reverse the alterations in FOXA2 and MUC5AC expression -by IL-13 and BV. However, LY294002 did not affect IL-13- and BV-induced changes in SPDEF expression. These findings indicate that BV inhibits MUC5AC production through the regulation of SPDEF and FOXA2. The inhibition of MUC5AC production through FOXA2 is mediated via the suppression of PI3K/AKT activation by BV. BV may be helpful in the prevention of mucus metaplasia in asthma.

Role of STAT3 Transcription Factor in Pathogenesis of Bronchial Asthma

Bronchial asthma is a heterogeneous chronic inflammatory disease of airways. The studies of molecular and cellular mechanisms of bronchial asthma have established that a wide range of immune (T and B cells, eosinophils, neutrophils, macrophages, etc.) and structural (epithelial and endothelial) cells are involved in its pathogenesis. These cells are activated in response to external stimuli (bacteria, viruses, allergens, and other pollutants) and produce pro-inflammatory factors (cytokines, chemokines, metalloproteinases, etc.), which ultimately leads to the initiation of pathological processes in the lungs. Genes encoding transcription factors of the STAT family (signal transducer and activator of transcription), that includes seven representatives, are involved in the cell activation. Recent studies have shown that the transcription factor STAT3 plays an important role in the activation of the abovementioned cells, thus contributing to the development of asthma. In animal studies, selective inhibition of STAT3 significantly reduces the severity of lung inflammation, which indicates its potential as a therapeutic target. In this review, we describe the mechanisms of STAT3 activation and its role in polarization of Th2/Th17 cells and M2 macrophages, as well as in the dysfunction of endothelial cells, which ultimately leads to development of bronchial asthma symptoms, such as infiltration of neutrophils and eosinophils into the lungs, bronchial hyperreactivity, and the respiratory tract remodeling.

Cytokine changes in fatal cases of paraquat poisoning

Cytokine-mediated inflammation is involved in the pathophysiology of paraquat toxicity. Nevertheless, few human studies have examined fluctuations in circulating cytokine levels. Blood samples were obtained from 21 patients with paraquat poisoning and compared to those of 18 healthy controls. All paraquat patients received a standard detoxification protocol composed of hemoperfusion, pulse therapies of methylprednisolone and cyclophosphamide, followed by dexamethasone therapy. Nonsurvivors not only had higher scores for the severity index of paraquat poisoning (P=0.004) but also presented with higher white blood cell counts (P=0.046) than survivors. Multiplex immunoassays revealed higher circulating levels of interleukin 2 (IL-2), interleukin 9 (IL-9), interleukin 10 (IL-10) and macrophage inflammatory protein-1 beta (MIP-1β) in survivors than in healthy controls. Furthermore, the circulating levels of interleukin 1 beta (IL-1β), IL-2, interleukin 5 (IL-5), interleukin 8 (IL-8), IL-9, IL-10, interleukin 12 (IL-12 p70), interleukin 17A (IL-17A), eotaxin, granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein-1 (MCP-1), interferon gamma-induced protein 10 (IP-10) and MIP-1β were higher in nonsurvivors than in healthy controls. Finally, the circulating levels of IL-1β and MCP-1 were higher in nonsurvivors than in survivors. Therefore, the observation of cytokine-mediated inflammation is in line with the detoxification protocol because glucocorticoids and cyclophosphamide are potent anti-inflammatory agents. Additionally, circulating levels of IL-1β and MCP-1 could serve as promising prognostic markers for patients with paraquat poisoning.

Different Phenotypes in Asthma: Clinical Findings and Experimental Animal Models

Asthma is a respiratory allergic disease presenting a high prevalence worldwide, and it is responsible for several complications throughout life, including death. Fortunately, asthma is no longer recognized as a unique manifestation but as a very heterogenic manifestation. Its phenotypes and endotypes are known, respectively, as pathologic and molecular features that might not be directly associated with each other. The increasing number of studies covering this issue has brought significant insights and knowledge that are constantly expanding. In this review, we intended to summarize this new information obtained from clinical studies, which not only allowed for the creation of patient clusters by means of personalized medicine and a deeper molecular evaluation, but also created a connection with data obtained from experimental models, especially murine models. We gathered information regarding sensitization and trigger and emphasizing the most relevant phenotypes and endotypes, such as Th2-^high asthma and Th2-^low asthma, which included smoking and obesity-related asthma and mixed and paucigranulocytic asthma, not only in physiopathology and the clinic but also in how these phenotypes can be determined with relative similarity using murine models. We also further investigated how clinical studies have been treating patients using newly developed drugs focusing on specific biomarkers that are more relevant according to the patient's clinical manifestation of the disease.

Inflammation in Asthma Pathogenesis: Role of T cells, Macrophages, Epithelial Cells and Type 2 Inflammation

Asthma is a chronic disease with abnormal inflammatory and immunological responses. The disease initiated by antigens in subjects with genetic susceptibility. However, environmental factors play a role in the initiation and exacerbation of asthma attack. Asthma is T helper 2 (Th2)-cell-mediated disease. Recent studies indicated that asthma is not a single disease entity, but it is with multiple phenotypes and endotypes. The pathophysiological changes in asthma included a series of subsequent continuous vicious circle of cellular activation contributed to induction of chemokines and cytokines that potentiate inflammation. The heterogeneity of asthma influenced the treatment response. The asthma pathogenesis driven by varied set of cells such as eosinophils, basophils, neutrophils, mast cells, macrophages, epithelial cells and T cells. In this review the role of T cells, macrophage, and epithelial cells are discussed.

Recent trends of NFκB decoy oligodeoxynucleotide-based nanotherapeutics in lung diseases

Nuclear factor κB (NFκB) is a unique protein complex that plays a major role in lung inflammation and respiratory dysfunction. The NFκB signaling pathway, therefore becomes an avenue for the development of potential pharmacological interventions, especially in situations where chronic inflammation is often constitutively active and plays a key role in the pathogenesis and progression of the disease. NFκB decoy oligodeoxynucleotides (ODNs) are double-stranded and carry NFκB binding sequences. They prevent the formation of NFκB-mediated inflammatory cytokines and thus have been employed in the treatment of a variety of chronic inflammatory diseases. However, the systemic administration of naked decoy ODNs restricts their therapeutic effectiveness because of their poor pharmacokinetic profile, instability, degradation by cellular enzymes and their low cellular uptake. Both structural modification and nanotechnology have shown promising results in enhancing the pharmacokinetic profiles of potent therapeutic substances and have also shown great potential in the treatment of respiratory diseases such as asthma, chronic obstructive pulmonary disease and cystic fibrosis. In this review, we examine the contribution of NFκB activation in respiratory diseases and recent advancements in the therapeutic use of decoy ODNs. In addition, we also highlight the limitations and challenges in use of decoy ODNs as therapeutic molecules, cellular uptake of decoy ODNs, and the current need for novel delivery systems to provide efficient delivery of decoy ODNs. Furthermore, this review provides a common platform for discussion on the existence of decoy ODNs, as well as outlining perspectives on the latest generation of delivery systems that encapsulate decoy ODNs and target NFκB in respiratory diseases.

Infection-Associated Mechanisms of Neuro-Inflammation and Neuro-Immune Crosstalk in Chronic Respiratory Diseases

Chronic obstructive airway diseases are characterized by airflow obstruction and airflow limitation as well as chronic airway inflammation. Especially bronchial asthma and chronic obstructive pulmonary disease (COPD) cause considerable morbidity and mortality worldwide, can be difficult to treat, and ultimately lack cures. While there are substantial knowledge gaps with respect to disease pathophysiology, our awareness of the role of neurological and neuro-immunological processes in the development of symptoms, the progression, and the outcome of these chronic obstructive respiratory diseases, is growing. Likewise, the role of pathogenic and colonizing microorganisms of the respiratory tract in the development and manifestation of asthma and COPD is increasingly appreciated. However, their role remains poorly understood with respect to the underlying mechanisms. Common bacteria and viruses causing respiratory infections and exacerbations of chronic obstructive respiratory diseases have also been implicated to affect the local neuro-immune crosstalk. In this review, we provide an overview of previously described neuro-immune interactions in asthma, COPD, and respiratory infections that support the hypothesis of a neuro-immunological component in the interplay between chronic obstructive respiratory diseases, respiratory infections, and respiratory microbial colonization.

Basophils Orchestrating Eosinophils' Chemotaxis and Function in Allergic Inflammation

Eosinophils are well known to contribute significantly to Th2 immunity, such as allergic inflammations. Although basophils have often not been considered in the pathogenicity of allergic dermatitis and asthma, their role in Th2 immunity has become apparent in recent years. Eosinophils and basophils are present at sites of allergic inflammations. It is therefore reasonable to speculate that these two types of granulocytes interact in vivo. In various experimental allergy models, basophils and eosinophils appear to be closely linked by directly or indirectly influencing each other since they are responsive to similar cytokines and chemokines. Indeed, basophils are shown to be the gatekeepers that are capable of regulating eosinophil entry into inflammatory tissue sites through activation-induced interactions with endothelium. However, the direct evidence that eosinophils and basophils interact is still rarely described. Nevertheless, new findings on the regulation and function of eosinophils and basophils biology reported in the last 25 years have shed some light on their potential interaction. This review will focus on the current knowledge that basophils may regulate the biology of eosinophil in atopic dermatitis and allergic asthma.

A20-OVA Nanoparticles Inhibit Allergic Asthma in a Murine Model

The skewed T helper (Th) 2 response plays a critical role in the pathogenesis of allergic asthma. Regulatory T (Treg) cells and the regulatory cytokines are required in maintaining the homeostasis in the body. This study aims to determine the effects of a poly(lactic-co-glycolic) acid (PLGA)-ovalbumin (OVA)+A20 (a ubiquitin E3 ligase) nanovaccine on inhibiting allergic asthma in a murine model. In this study, A20 and OVA (a model antigen) were encapsulated into PLGA to be a nanovaccine (PLGA-OVA+A20). An allergic asthma murine model was developed with OVA as the specific antigen to test the role of PLGA-OVA+A20 nanovaccine in maintaining the immune homeostasis in the airway tissues. The results showed that PLGA-OVA+A20 nanovaccine inhibited the asthma responses in mice by suppressing Th2 inflammatory responses, promoting the generation of Treg cells in the airway tissues. We conclude that the PLGA-OVA+A20 nanovaccine has a marked inhibitory effect on the airway allergic response in sensitized mice by significantly promoting the generation of Treg cell and IL-10. The data suggest that PLGA-OVA+A20 has translational potential in the treatment of allergic asthma.

A Knock-Down Cell-Based Study for the Functional Analysis of Chloride Intracellular Channel 1 (CLIC1): Integrated Proteomics and Microarray Study

BACKGROUND

Previously, we detected that chloride intracellular channel 1 (CLIC1) was involved in the pathogenesis of atopic dermatitis (AD).

OBJECTIVE

In this study, we aimed to use high-throughput screening (HTS) approaches to identify critical factors associated with the function of CLIC1 in knock-down cells.

METHODS

We down-regulated CLIC1 in human A549 cells via siRNA and then conducted serial HTS studies, including proteomics integrated with a microarray and the implementation of bioinformatics algorithms.

RESULTS

Together, these approaches identified several important proteins and genes associated with the function of CLIC1. These proteins and genes included tumor rejection antigen (gp96) 1, nucleophosmin, annexin I, keratin 1 and 10, FLNA protein, enolase 1, and metalloprotease 1, which were found using two-dimensional electrophoresis (2-DE) proteomics. Separately, NTNG1, SEMA5A, CLEC3A, GRPR, GNGT2, GRM5, GRM7, DNMT3B, CXCR5, CCL11, CD86, IL2, MNDA, TLR5, IL23R, DPP6, DLGAP1, CAT, GSTA1, GSTA2, GSTA5, CYP2E1, ADH1A, ESR1, ARRDC3, A1F1, CCL5, CASP8, DNTT, SQSTM1, PCYT1A, and SLCO4C1 were found using a DNA microarray integrated with PPI mapping.

CONCLUSION

CCL11 is thought to be a particularly critical gene among the candidate genes detected in this study. By integrating the datasets and utilizing the strengths of HTS, we obtained new insights into the functional role of CLIC1, including the use of CLIC1-associated applications in the treatment of human diseases such as AD.

Lysophospholipids in Lung Inflammatory Diseases

The lysophospholipids (LPLs) belong to a group of bioactive lipids that play pivotal roles in several physiological and pathological processes. LPLs are derivatives of phospholipids and consist of a single hydrophobic fatty acid chain, a hydrophilic head, and a phosphate group with or without a large molecule attached. Among the LPLs, lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P) are the simplest, and have been shown to be involved in lung inflammatory symptoms and diseases such as acute lung injury, asthma, and chronic obstructive pulmonary diseases. G protein-coupled receptors (GPCRs) mediate LPA and S1P signaling. In this chapter, we will discuss on the role of LPA, S1P, their metabolizing enzymes, inhibitors or agonists of their receptors, and their GPCR-mediated signaling in lung inflammatory symptoms and diseases, focusing specially on acute respiratory distress syndrome, asthma, and chronic obstructive pulmonary disease.

Childhood asthma: Novel endotyping by cytokines, validated through sensitization profiles and clinical characteristics

BACKGROUND

Specific allergy sensitization pattern, using "component-resolved diagnosis" (CRD), is a central component of allergy and asthma in childhood. Besides this, allergic asthma has been characterized by a Th2-shifted endotype with elevation of classical Th2 cytokines. Recently, other endotypes with distinct mechanisms focusing on cytokine regulation evolved, yet those pathways are still not well understood.

OBJECTIVE

(a) To define reproducible immunological endotypes using cytokine expression in an asthma cohort and (b) to characterize their sensitization profile and clinical phenotype.

METHODS

Supernatants from PBMCs of 234 children (median age 10 years) of an asthma cohort were analysed for cytokine expressions. The children were split into a training (n = 49) and validation (n = 185) group. The training group was used to identify immunological endotypes by clustering cytokine expressions, which were then assessed regarding clinical characteristics and specific IgE of recombinant allergen components. Next, our findings were validated in the validation group.

RESULTS

We identified novel endotypes based on primarily unstimulated cytokine expression. One endotype showed an IFN-γ/Interleukin (IL)-17/IL-5 predominance, a different sensitization pattern (high in birch/apple; p < .01), and inferior lung function (p < .01). A second endotype grouped young children with food allergy and reduced lung function. Our findings were reproducible in the validation group.

CONCLUSION AND CLINICAL RELEVANCE

We identified two novel clinical asthma endotypes via cytokine expression pattern with distinct sensitization patterns. These novel findings are critical for clinical guidance and open avenues for identifying underlying mechanisms and more patient-specific therapies.

Requirement of Gαi1 and Gαi3 in interleukin-4-induced signaling, macrophage M2 polarization and allergic asthma response

IL-4 induces Akt activation in macrophages, required for full M2 (alternative) polarization. We examined the roles of Gαi1 and Gαi3 in M2 polarization using multiple genetic methods.

Methods and Results: In MEFs and primary murine BMDMs, Gαi1/3 shRNA, knockout or dominant negative mutations attenuated IL-4-induced IL4Rα endocytosis, Gab1 recruitment as well as Akt activation, leaving STAT6 signaling unaffected. Following IL-4 stimulation, Gαi1/3 proteins associated with the intracellular domain of IL-4Rα and the APPL1 adaptor, to mediate IL-4Rα endosomal traffic and Gab1-Akt activation in BMDMs. In contrast, gene silencing of Gαi1/3 with shRNA or knockout resulted in BMDMs that were refractory to IL-4-induced M2 polarization. Conversely, Gαi1/3-overexpressed BMDMs displayed preferred M2 response with IL-4 stimulation. In primary human macrophages IL-4-induced Akt activation and Th2 genes expression were inhibited with Gαi1/3 silencing, but augmented with Gαi1/3 overexpression. In Gαi1/3 double knockout (DKO) mice, M2 polarization, by injection of IL-4 complex or chitin, was potently inhibited. Moreover, in a murine model of asthma, ovalbumin-induced airway inflammation and hyperresponsiveness were largely impaired in Gαi1/3 DKO mice.

Conclusion: These findings highlight novel and essential roles for Gαi1/3 in regulating IL-4-induced signaling, macrophage M2 polarization and allergic asthma response.

IL-4 and IL-17 Are Required for House Dust Mite-Driven Airway Hyperresponsiveness in Autoimmune Diabetes-Prone Non-Obese Diabetic Mice

Allergic asthma is characterized by airway inflammation with a Th2-type cytokine profile, hyper-IgE production, mucus hypersecretion, and airway hyperreactivity (AHR). It is increasingly recognized that asthma is a heterogeneous disease implicating complex immune mechanisms resulting in distinct endotypes observed in patients. In this study, we showed that non-obese diabetic (NOD) mice, which spontaneously develop autoimmune diabetes, undergo more severe allergic asthma airway inflammation and AHR than pro-Th2 BALB/c mice upon house dust mite (HDM) sensitization and challenge. The use of IL-4-deficient NOD mice and the in vivo neutralization of IL-17 demonstrated that both IL-4 and IL-17 are responsible by the exacerbated airway inflammation and AHR observed in NOD mice. Overall, our findings indicate that autoimmune diabetes-prone NOD mice might become useful as a new HDM-induced asthma model to elucidate allergic dysimmune mechanisms involving Th2 and Th17 responses that could better mimic some asthmatic endoytpes.

Interleukin-13 as a target to alleviate severe coronavirus disease 2019 and restore lung homeostasis

The ongoing coronavirus disease (COVID-19) pandemic urgently requires the availability of interventions that improve outcomes for those with severe disease. Since severe acute respiratory syndrome coronavirus 2 infection is characterized by dysregulated lung mucosae, and that mucosal homeostasis is heavily influenced by interleukin (IL)-13 activity, we explore recent findings indicating that IL-13 production is proportional to disease severity. We propose that excessive IL-13 contributes to the progression of severe/fatal COVID-19 by (1) promoting the recruitment of immune cells that express inflammatory cytokines, causing a cytokine storm that results in widespread destruction of lung tissue, (2) directly facilitating tissue-remodeling that causes airway hyperinflammation and obstruction, and (3) diverting the immune system away from developing high-quality cytotoxic T cells that confer effective anti-viral immunity. These factors may cumulatively result in significant lung distress, multi-organ failure, and death. Here, we suggest repurposing existing IL-13-inhibiting interventions, including antibody therapies routinely used for allergic lung hyperinflammation, as well as viral vector-based approaches, to alleviate disease. Since many of these strategies have previously been shown to be both safe and effective, this could prove to be a highly cost-effective solution.

Relevance for Patients

There remains a desperate need to establish medical interventions that reliably improves outcomes for patients suffering from COVID-19. We explore the role of IL-13 in maintaining homeostasis at the lung mucosae and propose that its dysregulation during viral infection may propagate the hallmarks of severe disease - further exploration may provide a platform for invaluable therapeutics.