Activated p38 MAPK in Peripheral Blood Monocytes of Steroid Resistant Asthmatics

Demethylzeylasteral (T-96) Alleviates Allergic Asthma via Inhibiting MAPK/ERK and NF-κB Pathway

INTRODUCTION

Demethylzeylasteral (T-96), a new extract of Tripterygium wilfordii Hook F, exerted immunomodulatory properties in autoimmune diseases, but its effect on airway inflammatory diseases remains unclear. Our study aims to explore the protective effect and underlying mechanism of T-96 in allergic asthma.

METHODS

The OVA-induced asthmatic mice were administered by gavage with T-96 (0.1 mg/10 g, 0.3 mg/10 g, or 0.6 mg/10 g) 1 h before each challenge. The airway hyperresponsiveness was assessed, pathological changes were evaluated by HE and PAS staining, and expressions of Th2 cytokines were determined by PCR and ELISA. The activation of MAPK/ERK and NF-κB pathway was assessed by western blot.

RESULTS

T-96 significantly relieved airway hyperresponsiveness in asthmatic mice, evidenced by reduced airway resistance (Raw) and increased lung compliance dynamic compliance (Cdyn). Also, enhanced inflammatory infiltration and mucus hypersecretion were ameliorated in lungs of asthmatic mice following increasing doses of T-96 treatment, accompanied by decreased eosinophils in bronchoalveolar lavage fluid (BALF), IgE and OVA-specific IgE levels in serum, and downregulated IL-5 and IL-13 expressions in BALF and lung tissues as well. Notably, phosphorylation levels of p38 MAPK, ERK, and p65 NF-κB were obviously increased in asthmatic mice compared with the control group, which were then abrogated upon T-96 treatment.

CONCLUSION

This study first revealed that T-96 alleviated allergic airway inflammation and airway hyperresponsiveness via inhibiting MAPK/ERK and NF-κB pathway. Thus, T-96 could potentially act as a new anti-inflammatory agent in allergic asthma.

Phosphorylated p38 MAP kinase expression by leucocytes is increased in allergic humans and associated with IgE responses

Mitogen-activated protein kinases (MAPK) activate cascades that regulate cell proliferation, differentiation and death. Phosphorylated (phos-)p38 MAPK is a cell-signalling pathway associated with Th2 cytokine responses, which is required for immunoglobulin (Ig)E production. It is unknown whether MAPK are associated with IgE production. We examine the evidence linking p38 MAPK to inflammatory responses. Phos-p38, extracellular signal-related kinase (ERK) and c-JUN-n terminal (JNK) MAPK expression by blood leucocyte subsets and levels of serum Igs were measured in blood from adults with asthma and/or rhinoconjunctivitis (N = 28) and non-asthma (N = 10) (flow cytometry, microfluorenzymeimmunoassay). Peripheral blood mononuclear cells (PBMC) from allergic subjects were cultured for 10 days ± anti-CD40/recombinant IL-4 ± inhibitor of phos-P38. Culture supernatants were assayed for IgE (ELISA). Phos-p38 MAPK expression by all leucocyte subsets of allergic subjects was associated with serum IgE levels (p ≤ 0.01), after adjusting for cell counts, age, sex, race and smoking status (p ≤ 0.04). Leucocyte expression of phos-ERK and JNK did not correlate with IgE (p = 0.09-0.99). Instead, phos-ERK expression was associated with serum IgG. When PBMC from atopic subjects were cultured for 10 days with anti-CD40/rhIL-4, IgE levels were 26.2 ± 18 ng/mL. Inclusion of SB202190 (5-20 μg/mL), a specific inhibitor of phos-p38 MAPK, in culture suppressed IgE production in dose-dependent manner, with peak suppression obtained with SB202190 at 20 μg/mL (82.1% ± 11.8) (p = 0.0001), with virtually no cytotoxicity (<5%). Different MAPK pathways may be associated with IgE (p38) and IgG (ERK) responses. Phos-p38 MAPK can be a potential anti-allergy drug target.

Bioinformatic analysis and experimental validation of the potential gene in the airway inflammation of steroid-resistant asthma

Steroid-resistant asthma is a troublesome clinical problem in public health. The pathogenesis of steroid-resistant asthma is complex and remains to be explored. In our work, the online Gene Expression Omnibus microarray dataset GSE7368 was used to explore differentially expressed genes (DEGs) between steroid-resistant asthma patients and steroid-sensitive asthma patients. Tissue-specific gene expression of DEGs was analyzed using BioGPS. The enrichment analyses were performed using GO, KEGG, and GSEA analysis. The protein-protein interaction network and key gene cluster were constructed using STRING, Cytoscape, MCODE, and Cytohubba. A steroid-resistant neutrophilic asthma mouse model was established using lipopolysaccharide (LPS) and ovalbumin (OVA). An LPS-stimulated J744A.1 macrophage model was prepared to validate the underlying mechanism of the interesting DEG gene using the quantitative reverse transcription-polymerase chain reaction (qRT-PCR). A total of 66 DEGs were identified, most of which were present in the hematologic/immune system. Enrichment analysis displayed that the enriched pathways were the IL-17 signaling pathway, MAPK signal pathway, Toll-like receptor signaling pathway, and so on. DUSP2, as one of the top upregulated DEGs, has not been clearly demonstrated in steroid-resistant asthma. In our study, we observed that the salubrinal administration (DUSP2 inhibitor) reversed neutrophilic airway inflammation and cytokine responses (IL-17A, TNF-α) in a steroid-resistant asthma mouse model. We also found that salubrinal treatment reduced inflammatory cytokines (CXCL10 and IL-1β) in LPS-stimulated J744A.1 macrophages. DUSP2 may be a candidate target for the therapy of steroid-resistant asthma.

The Correlation of PM2.5 Exposure with Acute Attack and Steroid Sensitivity in Asthma

Bronchial asthma is a common chronic inflammatory disease of the respiratory system. Asthma primarily manifests in reversible airflow limitation and airway inflammation, airway remodeling, and persistent airway hyperresponsiveness. PM2.5, also known as fine particulate matter, is the main component of air pollution and refers to particulate matter with an aerodynamic diameter of ≤2.5 μm. PM2.5 can be suspended in the air for an extensive time and, in addition, can contain or adsorb heavy metals, toxic gases, polycyclic aromatic hydrocarbons, bacterial viruses, and other harmful substances. Epidemiological studies have demonstrated that, in addition to increasing the incidence of asthma, PM2.5 exposure results in a significant increase in the incidence of hospital visits and deaths due to acute asthma attacks. Furthermore, PM2.5 was reported to induce glucocorticoid resistance in asthmatic individuals. Although various countries have implemented strict control measures, due to the wide range of PM2.5 sources, complex components, and unknown pathogenic mechanisms involving the atmosphere, environment, chemistry, and toxicology, PM2.5 damage to human health still cannot be effectively controlled. In this present review, we summarized the current knowledge base regarding the relationship between PM2.5 toxicity and the onset, acute attack prevalence, and steroid sensitivity in asthma.

Glucocorticoid Insensitivity in Asthma: The Unique Role for Airway Smooth Muscle Cells

Although most patients with asthma symptoms are well controlled by inhaled glucocorticoids (GCs), a subgroup of patients suffering from severe asthma respond poorly to GC therapy. Such GC insensitivity (GCI) represents a profound challenge in managing patients with asthma. Even though GCI in patients with severe asthma has been investigated by several groups using immune cells (peripheral blood mononuclear cells and alveolar macrophages), uncertainty exists regarding the underlying molecular mechanisms in non-immune cells, such as airway smooth cells (ASM) cells. In asthma, ASM cells are among the targets of GC therapy and have emerged as key contributors not only to bronchoconstriction but also to airway inflammation and remodeling, as implied by experimental and clinical evidence. We here summarize the current understanding of the actions/signaling of GCs in asthma, and specifically, GC receptor (GR) “site-specific phosphorylation” and its role in regulating GC actions. We also review some common pitfalls associated with studies investigating GCI and the inflammatory mediators linked to asthma severity. Finally, we discuss and contrast potential molecular mechanisms underlying the impairment of GC actions in immune cells versus non-immune cells such as ASM cells.

Molecular Mechanism Underlying Effects of Wumeiwan on Steroid-Dependent Asthma: A Network Pharmacology, Molecular Docking, and Experimental Verification Study

Background

Steroid-dependent asthma (SDA) is characterized by oral corticosteroid (OCS) resistance and dependence. Wumeiwan (WMW) showed potentials in reducing the dose of OCS of SDA patients based on our previous studies.

Methods

Network pharmacology was conducted to explore the molecular mechanism of WMW against SDA with the databases of TCMSP, STRING, etcetera. GO annotation and KEGG functional enrichment analysis were conducted by metascape database. Pymol performed the molecular docking. In the experiment, the OVA-induced plus descending dexamethasone intervention chronic asthmatic rat model was conducted. Lung pathological changes were analyzed by H&E, Masson, and IHC staining. Relative expressions of the gene were performed by real-time PCR.

Results

A total of 102 bioactive ingredients in WMW were identified, as well as 191 common targets were found from 241 predicted targets in WMW and 3539 SDA-related targets. The top five bioactive ingredients were identified as pivotal ingredients, which included quercetin, candletoxin A, palmidin A, kaempferol, and beta-sitosterol. Besides, 35 HUB genes were obtained from the PPI network, namely, TP53, AKT1, MAPK1, JUN, HSP90AA1, TNF, RELA, IL6, CXCL8, EGFR, etcetera. GO biological process analysis indicated that HUB genes were related to bacteria, transferase, cell differentiation, and steroid. KEGG pathway enrichment analysis indicated that the potential mechanism might be associated with IL-17 and MAPK signaling pathways. Molecular docking results supported these findings. H&E and Masson staining proved that WMW could reduce airway inflammation and remodeling of model rats, which might be related to the downward expression of IL-8 proved by IHC staining and real-time PCR.

Conclusion

WMW could be a complementary and alternative therapy for SDA by reducing airway inflammation.

Marine-Derived Compounds for the Potential Treatment of Glucocorticoid Resistance in Severe Asthma

One of the challenges to the management of severe asthma is the poor therapeutic response to treatment with glucocorticosteroids. Compounds derived from marine sources have received increasing interest in recent years due to their prominent biologically active properties for biomedical applications, as well as their sustainability and safety for drug development. Based on the pathobiological features associated with glucocorticoid resistance in severe asthma, many studies have already described many glucocorticoid resistance mechanisms as potential therapeutic targets. On the other hand, in the last decade, many studies described the potentially anti-inflammatory effects of marine-derived biologically active compounds. Analyzing the underlying anti-inflammatory mechanisms of action for these marine-derived biologically active compounds, we observed some of the targeted pathogenic molecular mechanisms similar to those described in glucocorticoid (GC) resistant asthma. This article gathers the marine-derived compounds targeting pathogenic molecular mechanism involved in GC resistant asthma and provides a basis for the development of effective marine-derived drugs.

Chronic Intermittent Hypoxia Reduces the Effects of Glucosteroid in Asthma via Activating the p38 MAPK Signaling Pathway

AIMS

Obstructive sleep apnea (OSA) is a risk factor for steroid-resistant (SR) asthma. However, the underlying mechanism is not well defined. This study aimed to investigate how chronic intermittent hypoxia (CIH), the main pathophysiology of OSA, influenced the effects of glucocorticoids (GCs) on asthma.

MAIN METHODS

The effects of dexamethasone (Dex) were determined using the ovalbumin (OVA)-challenged mouse model of asthma and transforming growth factor (TGF)-β treated airway smooth muscle cells (ASMCs), with or without CIH. The p38 MAPK signaling pathway activity was then detected in the mouse (n = 6) and ASMCs models (n = 6), which were both treated with the p38 MAPK inhibitor SB239063.

KEY FINDINGS

Under CIH, mouse pulmonary resistance value, inflammatory cells in bronchoalveolar lavage fluid (BALF), and inflammation scores increased in OVA-challenged combined with CIH exposure mice compared with OVA-challenged mice (p < 0.05). These indicators were similarly raised in the OVA + CIH + Dex group compared with the OVA + Dex group (P < 0.05). CIH exposure enhanced the activation of the p38 MAPK pathway, oxidative stress injury, and the expression of NF-κB both in lung tissue and ASMCs, which were reversed by treatment with Dex and SB239063. In the in vitro study, treatment with Dex and SB239063 decreased ASMCs proliferation induced by TGF-β combined with CIH and suppressed activation of the p38 MAPK pathway, oxidative stress injury, and NF-κB nuclear transcription (p < 0.05).

SIGNIFICANCE

These results indicated that CIH decreased GC sensitivity by activating the p38 MAPK signaling pathway.

Overexpression of the MSK1 Kinase in Patients With Chronic Lung Allograft Dysfunction and Its Confirmed Role in a Murine Model

BACKGROUND

Chronic lung allograft dysfunction (CLAD) and its obstructive form, the obliterative bronchiolitis (OB), are the main long-term complications related to high mortality rate postlung transplantation. CLAD treatment lacks a significant success in survival. Here, we investigated a new strategy through inhibition of the proinflammatory mitogen- and stress-activated kinase 1 (MSK1) kinase.

METHODS

MSK1 expression was assessed in a mouse OB model after heterotopic tracheal allotransplantation. Pharmacological inhibition of MSK1 (H89, fasudil, PHA767491) was evaluated in the murine model and in a translational model using human lung primary fibroblasts in proinflammatory conditions. MSK1 expression was graded over time in biopsies from a cohort of CLAD patients.

RESULTS

MSK1 mRNA progressively increased during OB (6.4-fold at D21 posttransplantation). Inhibition of MSK1 allowed to counteract the damage to the epithelium (56% restoration for H89), and abolished the recruitment of MHCII+ (94%) and T cells (100%) at the early inflammatory phase of OB. In addition, it markedly decreased the late fibroproliferative obstruction in allografts (48%). MSK1 inhibitors decreased production of IL-6 (whose transcription is under the control of MSK1) released from human lung fibroblasts (96%). Finally, we confirmed occurrence of a 2.9-fold increased MSK1 mRNA expression in lung biopsies in patients at 6 months before CLAD diagnosis as compared to recipients with stable lung function.

CONCLUSIONS

These findings suggest the overall interest of the MSK1 kinase either as a marker or as a potential therapeutic target in lung dysfunction posttransplantation.

Transcriptome analysis in Takifugu rubripes and Dicentrarchus labrax gills during Cryptocaryon irritans infection

Takifugu rubripes and Dicentrarchus labrax are important commercial fish in China that are under serious threat from Cryptocaryon irritans. C. irritans is a ciliated obligate parasite that causes marine white spot disease and leads to heavy economic losses. We analysed the transcriptome in the gills of T. rubripes and D. labrax to compare differentially expressed genes (DEGs) and pathways during infection with C. irritans. In total, we identified 6,901 and 35,736 DEGs from T. rubripes and D. labrax, respectively. All DEGs were annotated into GO terms; 6,901 DEGs from T. rubripes were assigned into 991 sub-categories, and 35,736 DEGs from D. labrax were assigned into 8,517 sub-categories. We mapped DEGs to the KEGG database and obtained 153 and 350 KEGG signalling pathways from T. rubripes and D. labrax, respectively. Immune-related categories included Toll-like receptors, MAPK, lysosome, C-type lectin receptor and NOD-like receptor signalling pathways were significantly enriched pathways. In immune-related signalling pathways, we found that AP-1, P38, IL-1β, HSP90 and PLA were significantly up-regulated DEGs in T. rubripes, but P38 and PLA were significantly down-regulated in D. labrax. In this study, transcriptome was used to analyse the difference between scaly and non-scaly fish infection by C. irritans, which not only provided a theoretical basis for the infection mechanism of C. irritans, but also laid a foundation for effectively inhibiting the occurrence of this disease. Our work provides further insight into the immune response of host resistance to C. irritans.

Glucocorticoid-dependent transcription in skin requires epidermal expression of the glucocorticoid receptor and is modulated by the mineralocorticoid receptor

Glucocorticoid (GC) actions are mediated through two closely related ligand-dependent transcription factors, the GC receptor (GR) and the mineralocorticoid receptor (MR). Given the wide and effective use of GCs to combat skin inflammatory diseases, it is important to understand the relative contribution of these receptors to the transcriptional response to topical GCs. We evaluated the gene expression profiles in the skin of mice with epidermal-specific loss of GR (GREKO), MR (MREKO), or both (double KO; DKO) in response to dexamethasone (Dex). The overall transcriptional response was abolished in GREKO and DKO skin suggesting dependence of the underlying dermis on the presence of epidermal GR. Indeed, the observed dermal GC resistance correlated with a constitutive decrease in GR activity and up-regulation of p38 activity in this skin compartment. Upon Dex treatment, more than 90% of differentially expressed genes (DEGs) in CO overlapped with MREKO. However, the number of DEGs was fourfold increased and the magnitude of response was higher in MREKO vs CO, affecting both gene induction and repression. Taken together our data reveal that, in the cutaneous transcriptional response to GCs mediated through endogenous receptors, epidermal GR is mandatory while epidermal MR acts as a chief modulator of gene expression.

Interleukin-35 sensitizes monocytes from patients with asthma to glucocorticoid therapy by regulating p38 MAPK

The activation of monocytes and macrophages is associated with steroid-resistant (SR) asthma. Interleukin-35 (IL-35) is an important anti-inflammatory cytokine, but its regulatory effects on monocytes in patients with SR asthma is not fully understood. Based on clinical response to oral prednisolone, 34 patients with steroid-sensitive (SS) asthma and 20 patients with SR asthma were enrolled in the present study. Serum IL-35 levels were analyzed using the Luminex 200 platform. Monocytes from patients with asthma were pretreated with IL-35 followed by dexamethasone (DEX) and lipopolysaccharide (LPS), then corticosteroid sensitivity was evaluated according to the half-maximal inhibitory concentration of DEX with respect to LPS-induced IL-6 maximal production in monocytes (DEX-IC₅₀). The percentage of maximal inhibition of IL-6 by DEX was presented as E_max. Phosphorylated-P38 mitogen activated kinase (p-p38 MAPK) and mitogen-activated protein kinase phosphatase-1 (MKP-1) were examined by flow cytometry and reverse transcription-quantitative PCR analysis, respectively. Glucocorticoid receptor (GR) binding to the glucocorticoid response element (GRE) was assessed by chromatin immunoprecipitation. Compared with patients with SS asthma, patients with SR asthma had lower IL-35 expression levels (P<0.05). Correlation analysis results demonstrated that the expression levels of IL-35 showed a weak negative correlation with log DEX-IC₅₀ (r=-0.351; P<0.01) and a moderate positive correlation with E_max value (r=0.4501; P<0.01) in all patients with asthma. Moreover, IL-35 enhanced DEX-suppressed IL-6 production and the DEX-induced upregulation of the MKP-1 mRNA expression level in monocytes from both patient groups (P<0.01). In addition, IL-35 inhibited p-p38 MAPK expression in monocytes, and these effects were mediated via an increase in DEX-induced GR binding to GRE. Therefore, IL-35 may be involved in the corticosteroid enhancing effects in monocytes of patients with SR and SS asthma, suggesting potential benefits of IL-35 supplementation in asthmatics with DEX.

Glycolysis Is Required for LPS-Induced Activation and Adhesion of Human CD14+CD16- Monocytes

Monocytes in humans consist of 3 subsets; CD14+CD16- (classical), CD14+CD16+ (intermediate) and CD14dimCD16+ (non-classical), which exhibit distinct and heterogeneous responses to activation. During acute inflammation CD14+CD16- monocytes are significantly elevated and migrate to the sites of injury via the adhesion cascade. The field of immunometabolism has begun to elucidate the importance of the engagement of specific metabolic pathways in immune cell function. Yet, little is known about monocyte metabolism and the role of metabolism in mediating monocyte activation and adherence to vessels. Accordingly, we aimed to determine whether manipulating the metabolism of CD14+CD16- monocytes alters their ability to become activated and adhere. We discovered that LPS stimulation increased the rate of glycolysis in human CD14+CD16- monocytes. Inhibition of glycolysis with 2-deoxy-D-glucose blunted LPS-induced activation and adhesion of monocytes. Mechanistically, we found that increased glycolysis was regulated by mTOR-induced glucose transporter (GLUT)-1. Furthermore, enhanced glycolysis increased accumulation of reactive oxygen species (ROS) and activation of p38 MAPK, which lead to activation and adhesion of monocytes. These findings reveal that glycolytic metabolism is critical for the activation of CD14+CD16- monocytes and contributes to our understanding of the interplay between metabolic substrate preference and immune cell function.

Mechanisms Underlying the Functional Cooperation Between PPARα and GRα to Attenuate Inflammatory Responses

Glucocorticoids (GCs) act via the glucocorticoid receptor (NR3C1, GRα) to combat overshooting responses to infectious stimuli, including lipopolysaccharide (LPS). As such, GCs inhibit the activity of downstream effector cytokines, such as tumor necrosis factor (TNF). PPARα (NR1C1) is a nuclear receptor described to function on the crossroad between lipid metabolism and control of inflammation. In the current work, we have investigated the molecular mechanism by which GCs and PPARα agonists cooperate to jointly inhibit NF-κB-driven expression in A549 cells. We discovered a nuclear mechanism that predominantly targets Mitogen- and Stress-activated protein Kinase-1 activation upon co-triggering GRα and PPARα. In vitro GST-pull down data further support that the anti-inflammatory mechanism may additionally involve a non-competitive physical interaction between the p65 subunit of NF-κB, GRα, and PPARα. Finally, to study metabolic effector target cells common to both receptors, we overlaid the effect of GRα and PPARα crosstalk in mouse primary hepatocytes under LPS-induced inflammatory conditions on a genome-wide level. RNA-seq results revealed lipid metabolism genes that were upregulated and inflammatory genes that were additively downregulated. Validation at the cytokine protein level finally supported a consistent additive anti-inflammatory response in hepatocytes.

[Pathogenesis of steroid-resistant asthma and the influence of vitamin D]

Glucocorticoid (GC) is currently the most effective drug for controlling persistent asthma; however, there is a significant difference in the response to GC among patients with asthma. Steroid-resistant asthma is one of the subtypes of asthma and has poor response to high-dose GC treatment. It may affect the quality of life of patients and even threaten their lives. Therefore, it is of great significance to explore the pathogenesis of steroid-resistant asthma and related targeted treatment strategy. In recent years, a variety of pathogeneses have been found to participate in the development and progression of steroid-resistant asthma, including the reduction in the binding between GC receptor and GC, the increase in the expression of GC receptor β, over-activation of nuclear transcription factor activating protein 1 and nuclear factor-κB, abnormality in histone acetylation, and immune-mediated cytokine dysregulation. In addition, many studies have shown that vitamin D can improve the sensitivity to GC among patients with steroid-resistant asthma. This article reviews the pathogenesis of steroid-resistant asthma and the influence of vitamin D.

[Pathogenesis of steroid-resistant asthma and the influence of vitamin D]

Glucocorticoid (GC) is currently the most effective drug for controlling persistent asthma; however, there is a significant difference in the response to GC among patients with asthma. Steroid-resistant asthma is one of the subtypes of asthma and has poor response to high-dose GC treatment. It may affect the quality of life of patients and even threaten their lives. Therefore, it is of great significance to explore the pathogenesis of steroid-resistant asthma and related targeted treatment strategy. In recent years, a variety of pathogeneses have been found to participate in the development and progression of steroid-resistant asthma, including the reduction in the binding between GC receptor and GC, the increase in the expression of GC receptor β, over-activation of nuclear transcription factor activating protein 1 and nuclear factor-κB, abnormality in histone acetylation, and immune-mediated cytokine dysregulation. In addition, many studies have shown that vitamin D can improve the sensitivity to GC among patients with steroid-resistant asthma. This article reviews the pathogenesis of steroid-resistant asthma and the influence of vitamin D.

Airway smooth muscle cells are insensitive to the anti-proliferative effects of corticosteroids: The novel role of insulin growth factor binding Protein-1 in asthma

Airway remodeling in asthma manifests, in part, as enhanced airway smooth muscle (ASM) mass, due to myocyte proliferation. While the anti-proliferative effects of glucocorticoid (GC) were investigated in normal ASM cells (NASMC), little is known about such effects in ASM cells derived from asthma subjects (AASMC). We posit that GC differentially modulates mitogen-induced proliferation of AASMC and NASMC. Cells were cultured, starved, then treated with Epidermal growth factor (EGF) (10 ng/ml) and Platelet-derived growth factor (PDGF) (10 ng/ml) for 24 h and/or fluticasone propionate (FP) (100 nM) added 2 h before. Cell counts and flow cytometry analyses showed that FP failed to decrease the cell number of and DNA synthesis in AASMC irrespective of mitogens used. We also examine the ability of Insulin Growth Factor Binding Protein-1 (IGFBP-1), a steroid-inducible gene that deters cell growth in other cell types, to inhibit proliferation of AASMC where FP failed. We found that FP increased IGFBP1 mRNA and protein levels. Interestingly, the addition of IGFBP1 (1 μg/ml) to FP completely inhibited the proliferation of AASMC irrespective to the mitogens used. Further investigation of different signaling molecules involved in ASM growth and GC receptor functions (Protein kinase B (PKB/AKT), Mitogen-activated protein kinases (MAPKs), Focal Adhesion Kinase (FAK)) showed that IGFBP-1 selectively decreased mitogen-induced p38 phosphorylation in AASMC. Collectively, our results show the insensitivity of AASMC to the anti-proliferative effects of GC, and demonstrate the ability of IGFBP1 to modulate AASMC growth representing, hence, a promising strategy to control ASM growth in subjects with GC insensitive asthma.

Mucin 1 deficiency mediates corticosteroid insensitivity in asthma

BACKGROUND

The loss of corticosteroid efficacy is an important issue in severe asthma management and may lead to poor asthma control and deterioration of airflow. Recent data indicate that Mucin 1 (MUC1) membrane mucin can mediate corticosteroid efficacy in chronic rhinosinusitis, but the role of MUC1 in uncontrolled severe asthma is unknown. The objective was to analyze the previously unexplored role of MUC1 on corticosteroid efficacy in asthma.

METHODS

Mucin 1 expression was evaluated by real-time PCR in human bronchial epithelial cells (HBEC) and blood neutrophils from uncontrolled severe asthma (n = 27), controlled mild asthma (n = 16), and healthy subjects (n = 13). IL-8, MMP9, and GM-CSF were measured by ELISA in HBEC and neutrophils. An asthma model of ovalbumin (OVA) was used in MUC1 KO and WT C57BL/6 mice according to ARRIVE guidelines.

RESULTS

Mucin 1-CT expression was downregulated in bronchial epithelial cells and peripheral blood neutrophils from severe asthma patients compared with mild asthma and healthy subjects (P < 0.05). Daily dose of inhaled corticosteroids (ICS) inversely correlated with MUC1 expression in neutrophils from mild and severe asthma (ρ = -0.71; P < 0.0001). Dexamethasone showed lower anti-inflammatory effects in severe asthma peripheral blood neutrophils and HBECs stimulated with lipopolysaccharide (LPS) than in cells from mild asthma. Glucocorticoid receptor (GR)-α phosphorylated at serine 226 was increased in cells from severe asthma, and the MUC1-CT/GRα complex was downregulated in severe asthma cells. OVA asthma model in MUC1 KO mice was resistant to the anti-inflammatory effects of dexamethasone.

CONCLUSION

Mucin 1-CT modulates corticosteroid efficacy in vitro and in vivo asthma models.

Salidroside protects against foam cell formation and apoptosis, possibly via the MAPK and AKT signaling pathways

BACKGROUND

Foam cell formation and apoptosis are closely associated with atherosclerosis pathogenesis. We determined the effect of salidroside on oxidized low-density lipoprotein (ox-LDL)-induced foam cell formation and apoptosis in THP1 human acute monocytic leukemia cells and investigated the associated molecular mechanisms.

METHODS

THP1-derived macrophages were incubated with salidroside for 5 h and then exposed to ox-LDL for 24 h to induce foam cell formation. Cytotoxicity, lipid deposition, apoptosis, and the expression of various proteins were tested using the CCK8 kit, Oil Red O staining, flow cytometry, and western blotting, respectively.

RESULTS

Ox-LDL treatment alone promoted macrophage-derived foam cell formation, while salidroside treatment alone inhibited it (p < 0.05). The number of early/late apoptotic cells decreased with salidroside treatment in a dose-dependent manner (p < 0.05). Salidroside dramatically upregulated nuclear factor erythroid 2-related factor 2, but had no effect on heme oxygenase-1 expression; moreover, it markedly downregulated ox-LDL receptor 1 and upregulated ATP-binding cassette transporter A1. Salidroside also obviously decreased the phosphorylation of JNK, ERK, p38 MAPK, and increased that of Akt. However, the total expression of these proteins was not affected.

CONCLUSION

Based on our findings, we speculate that salidroside can suppress ox-LDL-induced THP1-derived foam cell formation and apoptosis, partly by regulating the MAPK and Akt signaling pathways.

Precision medicine in patients with allergic diseases: Airway diseases and atopic dermatitis-PRACTALL document of the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma & Immunology

In this consensus document we summarize the current knowledge on major asthma, rhinitis, and atopic dermatitis endotypes under the auspices of the PRACTALL collaboration platform. PRACTALL is an initiative of the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma & Immunology aiming to harmonize the European and American approaches to best allergy practice and science. Precision medicine is of broad relevance for the management of asthma, rhinitis, and atopic dermatitis in the context of a better selection of treatment responders, risk prediction, and design of disease-modifying strategies. Progress has been made in profiling the type 2 immune response-driven asthma. The endotype driven approach for non-type 2 immune response asthma, rhinitis, and atopic dermatitis is lagging behind. Validation and qualification of biomarkers are needed to facilitate their translation into pathway-specific diagnostic tests. Wide consensus between academia, governmental regulators, and industry for further development and application of precision medicine in management of allergic diseases is of utmost importance. Improved knowledge of disease pathogenesis together with defining validated and qualified biomarkers are key approaches to precision medicine.

The Effect of Tacrolimus and Mycophenolic Acid on CD14+ Monocyte Activation and Function

Monocytes and macrophages play key roles in many disease states, including cellular and humoral rejection after solid organ transplantation (SOT). To suppress alloimmunity after SOT, immunosuppressive drug therapy is necessary. However, little is known about the effects of the immunosuppressive drugs tacrolimus and mycophenolic acid (MPA) on monocyte activation and function. Here, the effect of these immunosuppressants on monocytes was investigated by measuring phosphorylation of three intracellular signaling proteins which all have a major role in monocyte function: p38MAPK, ERK and Akt. In addition, biological functions downstream of these signaling pathways were studied, including cytokine production, phagocytosis and differentiation into macrophages. To this end, blood samples from healthy volunteers were spiked with diverse concentrations of tacrolimus and MPA. Tacrolimus (200 ng/ml) inhibited phosphorylation of p38MAPK by 30% (mean) in CD14+ monocytes which was significantly less than in activated CD3+ T cells (max 60%; p < 0.05). This immunosuppressive agent also partly inhibited p-AKT (14%). MPA, at a therapeutic concentration showed the strongest effect on p-AKT (27% inhibition). p-ERK was inhibited with a maximum of 15% after spiking with either tacrolimus or MPA. The production of IL-1β and phagocytosis by monocytes were not affected by tacrolimus concentrations, whereas MPA did inhibit IL-1β production by 50%. Monocyte/macrophage polarization was shifted to an M2-like phenotype in the presence of tacrolimus, while MPA increased the expression of M2 surface markers, including CD163 and CD200R, on M1 macrophages. These results show that tacrolimus and MPA do not strongly affect monocyte function, apart from a change in macrophage polarization, to a clinically relevant degree.

17-oxo-DHA displays additive anti-inflammatory effects with fluticasone propionate and inhibits the NLRP3 inflammasome

Chronic obstructive pulmonary disease (COPD) is characterized by reduced lung function associated with increased local and systemic inflammatory markers, such as TNFα and IL-1β. Glucocorticoids are used to treat this chronic disease, however their efficacy is low and new drugs are very much required. 17-oxo-DHA is a cyclooxygenase-2-dependent, electrophilic, α,β-unsaturated keto-derivative of docosahexaenoic acid with anti-inflammatory properties. We evaluated the action of 17-oxo-DHA alone or in combination with the steroid fluticasone propionate (FP) in peripheral blood mononuclear cells (PBMCs) from COPD patients and healthy individuals exposed to lipopolysaccharide. We show that PBMCs from COPD patients released higher levels of TNFα and IL-1β compared to controls. 17-oxo-DHA displayed strong anti-inflammatory effects. The addition of 17-oxo-DHA in combination with FP showed enhanced anti-inflammatory effects through the modulation of transcriptional and post-transcriptional mechanisms. 17-oxo-DHA, but not FP, was able to suppress the release of mature IL-1β through inhibition of the NLRP3 inflammasome. Furthermore, 17-oxo-DHA inhibited inflammasome-dependent degradation of the glucocorticoid receptor (GR). Our findings suggest that 17-oxo-DHA in combination with FP or other steroids might achieve higher therapeutic efficacy than steroids alone. Combined treatment might be particularly relevant in those conditions where increased inflammasome activation may lead to GR degradation and steroid-unresponsive inflammation.

Impaired anti-inflammatory action of glucocorticoid in neutrophil from patients with steroid-resistant asthma

BACKGROUND

Steroid resistant (SR) asthma is characterized by persistent airway inflammation that fails to resolve despite treatment with high doses of corticosteroids. Furthermore, SR patient airways show increased numbers neutrophils, which are less responsive to glucocorticoid. The present study seeks to determine whether dexamethasone (DEX) has different effect on neutrophils from steroid sensitive (SS) asthmatics compared to SR asthmatics.

METHODS

Adults with asthma (n = 38) were classified as SR or SS based on changes in lung FEV1% following a one-month inhaled corticosteroid (ICS) treatment. Blood samples were collected from all patients during their first visit of the study. Neutrophils isolated from the blood were cultured with dexamethasone and/or atopic asthmatic serum for 18 h. The mRNA expression of mitogen-activated protein kinase phosphatase-1 (MKP-1), a glucocorticoid transactivation target, and glucocorticoid-induced transcript 1 (GLCCI1), an early marker of glucocorticoid-induced apoptosis whose expression was associated with the response to inhaled glucocorticoids in asthma , was determined by real-time PCR, and ELISA was used to assess the pro-inflammatory cytokine IL-8 levels in the supernatant. Constitutive neutrophil apoptosis was detected by flow cytometry.

RESULTS

DEX significantly induced MKP-1 expression in both patients with SS and SR patients in a concentration-dependent manner, but greater induction was observed for SS patients at a low concentration (10^-6 M). Asthmatic serum alone showed no MKP-1expression, and there was impaired induction of MKP-1 by DEX in SR asthma patients. The expression of GLCCI1 was not induced in neutrophils with DEX or DEX/atopic asthmatic serum combination. Greater inhibition of IL-8 production was observed in neutrophils from patients with SS asthma treated with DEX/atopic asthmatic serum combination compared with SR asthma patients, though DEX alone showed the same effect on neutrophils from SS and SR asthma patients. Meanwhile, DEX dependent inhibition of constitutive neutrophil apoptosis was similar between SS asthma and SR asthma patients.

CONCLUSIONS

DEX exerted different effects on neutrophils from patients with SS asthma and SR asthma, which may contribute to glucocorticoid insensitivity.

Inundation of asthma target research: Untangling asthma riddles

Asthma is an inveterate inflammatory disorder, delineated by the airway inflammation, bronchial hyperresponsiveness (BHR) and airway wall remodeling. Although, asthma is a vague term, and is recognized as heterogenous entity encompassing different phenotypes. Targeting single mediator or receptor did not prove much clinical significant, as asthma is complex disease involving myriad inflammatory mediators. Asthma may probably involve a large number of different types of molecular and cellular components interacting through complex pathophysiological pathways. This review covers the past, present, and future therapeutic approaches and pathophysiological mechanisms of asthma. Furthermore, review describe importance of targeting several mediators/modulators and receptor antagonists involved in the physiopathology of asthma. Novel targets for asthma research include Galectins, Immunological targets, K ⁺ Channels, Kinases and Transcription Factors, Toll-like receptors, Selectins and Transient receptor potential channels. But recent developments in asthma research are very promising, these include Bitter taste receptors (TAS2R) abated airway obstruction in mouse model of asthma and Calcium-sensing receptor obliterate inflammation and in bronchial hyperresponsiveness allergic asthma. All these progresses in asthma targets, and asthma phenotypes exploration are auspicious in untangling of asthma riddles.

High-resolution metabolomics to identify urine biomarkers in corticosteroid-resistant asthmatic children

BACKGROUND

Corticosteroid (CS) treatment has been established as the first anti-inflammatory treatment for adults and children with asthma. However, a subset of patients fails to respond to combined systemic and inhaled CS treatment.

OBJECTIVE

This study was aimed at further understanding CS resistance among children with severe asthma.

METHODS

High-resolution metabolomics was performed on urine samples from CS-respondent (n = 15) and CS-nonrespondent (n = 15) children to determine possible urine biomarkers related to CS resistance. The metabolic phenotypes of CS responders and CS nonresponders were analyzed using bioinformatics including Manhattan plot with false- discovery rate, hierarchical cluster analysis, Kyoto Encyclopedia Genes and Genomes, and Mummichog pathway analysis.

RESULTS

The 2-way hierarchical cluster analysis study determined 30 metabolites showing significantly different levels between CS responders and CS nonresponders. The important metabolites annotated were 3,6-dihydronicotinic acid (126.05 m/z, RT: 106, [M+H]⁺), 3-methoxy-4-hydroxyphenyl(ethylene)glycol (185.05 m/z, RT: 155, [M+H]⁺), 3,4-dihydroxy-phenylalanine (198.07 m/z, RT: 446, [M+H]⁺), γ-glutamylcysteine (236.06 m/z, RT: 528, [M+S(34)+H]⁺), Cys-Gly, (253.06 m/z, RT: 528, [M-NH₃+H]⁺), and reduced Flavin mononucleotide (517.0794 m/z, RT: 533, [M+NaCl]⁺). Tyrosine metabolism, degradation of aromatic compounds, and glutathione metabolism are suggested to be significant pathways relating to CS resistance.

CONCLUSIONS

High-resolution metabolomics is a promising approach in asthma research. Five candidate markers were identified to be related to CS-resistant children with severe asthma. These compounds, upon validation, may contribute further in the understanding of CS resistance among children with severe asthma through the use of urine.

Kinases as Novel Therapeutic Targets in Asthma and Chronic Obstructive Pulmonary Disease

Multiple kinases play a critical role in orchestrating the chronic inflammation and structural changes in the respiratory tract of patients with asthma and chronic obstructive pulmonary disease (COPD). Kinases activate signaling pathways that lead to contraction of airway smooth muscle and release of inflammatory mediators (such as cytokines, chemokines, growth factors) as well as cell migration, activation, and proliferation. For this reason there has been great interest in the development of kinase inhibitors as anti-inflammatory therapies, particular where corticosteroids are less effective, as in severe asthma and COPD. However, it has proven difficult to develop selective kinase inhibitors that are both effective and safe after oral administration and this has led to a search for inhaled kinase inhibitors, which would reduce systemic exposure. Although many kinases have been implicated in inflammation and remodeling of airway disease, very few classes of drug have reached the stage of clinical studies in these diseases. The most promising drugs are p38 MAP kinases, isoenzyme-selective PI3-kinases, Janus-activated kinases, and Syk-kinases, and inhaled formulations of these drugs are now in development. There has also been interest in developing inhibitors that block more than one kinase, because these drugs may be more effective and with less risk of losing efficacy with time. No kinase inhibitors are yet on the market for the treatment of airway diseases, but as kinase inhibitors are improved from other therapeutic areas there is hope that these drugs may eventually prove useful in treating refractory asthma and COPD.