Project description:Rationale: Aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, has been considered as an important regulator for immune diseases. We have previously shown that AhR protects against allergic airway inflammation. The underlying mechanism, however, remains undetermined. Objectives: We sought to determine whether AhR specifically in Type II alveolar epithelial cells (AT2) modulates allergic airway inflammation and its underlying mechanisms. Methods: The role of AhR in AT2 cells in airway inflammation was investigated in a mouse model of asthma with AhR conditional knock out mice in AT2 cells (Sftpc-Cre;AhRflox/flox). The effect of AhR on allergen-induced autophagy was examined by both in vivo and in vitro analyses. The involvement of autophagy in airway inflammation was analyzed by using autophagy inhibitor chloroquine. The AhR-regulated gene profiling in AT2 cells was also investigated by RNA-seq analysis. Results: Sftpc-Cre; AhRflox/flox mice showed exacerbation of allergen-induced airway hyperresponsiveness and airway inflammation with elevated Th2 and airway epithelial-derived cytokines in bronchoalveolar lavage fluid (BALF). Notably, an increased allergen-induced autophagy was observed in the lung tissues of Sftpc-Cre; AhRflox/flox mice when compared with wild-type mice. Further analyses suggested a functional axis of AhR-TGF-β1 that is critical in driving allergic airway inflammation through regulating allergen-induced cellular autophagy. Furthermore, inhibition of autophagy suppressed allergic airway inflammation with decreased Th2 and epithelial cell-derived cytokines in BALFs. Additionally, RNA-seq analysis suggests that autophagy is one of the major pathways and CALCOCO2/NDP52 and S1009 are major autophagy-associated genes in AT2 cells that contribute to the AhR-mediated allergic airway inflammation. Conclusion: These results suggest that AhR in AT2 cells functions as a protective mechanism against allergic airway inflammation through controlling cell autophagy.
Project description:Inhaled allergen challenge of subjects with allergic asthma allows the study of mechanisms involved in allergen-induced airway inflammation. The objective of this study was to identify changes in the plasma proteome associated with a late phase response (LPR) causing airway obstruction occurring 4-8 hours after the initial early response. Serial plasma samples from asthmatics undergoing inhaled allergen challenge were analyzed. Mass spectrometry data was analyzed using a linear regression to model the relationship between the degree of airway obstruction during the LPR and plasma proteome changes evoked by the inhaled allergen challenge. Inhaled allergen challenge induced changes in the plasma proteome including upregulation of the protease inhibitors alpha-1-antitrypsin, alpha-1-antichymotrypsin and plasma serine protease inhibitor. Out of 396 quantified proteins, 150 showed a statistically significant change 23 hours post allergen challenge. Further proteomic changes were associated with the LPR, including altered levels of coagulation factors such as an increased factor XII A and a decreased von Willebrand factor. Allergic reactions to inhaled allergens in asthmatic subjects was associated with changes in a large proportion of the measured plasma proteome, whereof protease inhibitors show the largest changes, likely to influence the inflammatory response. Of several other proteins altered in relation to the LPR, many are associated with coagulation.
Project description:This study examines the innate immune response of human pluripotent stem cell derived airway epithelium. Immune challenge was performed with TNF-alpha or bacterial lipopolysaccharide (LPS) Airway epithelium differentiated from the ES line CA2 was compared to paired differentiated cells stimulated with either TNF-alpha or LPS
Project description:This protocol outlines a single-site mechanistic study aiming to investigate long RNAs differentially expressed in the airway epithelium of asthma patients both at baseline and in response to segmental airway allergen challenges. Over approximately 14 days, the study spanned three visits: Visit 1: Comprehensive characterization of participants, encompassing lung function testing, methacholine challenge testing, and allergen skin prick testing. Visit 2: Participants underwent bronchoscopy wherein three procedures were performed a. Epithelial brushings were performed in a segmental airway (baseline sample) b. Diluent (inactive control) was instilled into another segmental airway c. A small dose of allergen was administered into a third segmental airway using standardized cat or dust mite allergen extracts. Visit 3 (24 hours or 7 days post Visit 2): Another bronchoscopy was carried out to collect epithelial brushings in the diluent challenged and allergen challenged segments The collected epithelial brush samples underwent analysis for mRNA expression in the epithelial brushings. The study successfully incorporated a total of 23 subjects, which included 18 asthmatics (with stable or well-controlled conditions), 2 allergic non-asthmatics, and 3 non-allergic non-asthmatics.
Project description:Cigarette smoke (CS)-induced airway inflammation is an important pathologic feature of chronic obstructive pulmonary disease (COPD). Recent studies suggest a potential role of JunD in the regulation of inflammation, but its role in CS-induced airway inflammation has not been reported. This study aimed to determine its role in CS-induced airway inflammation through bioinformatics analysis and in vitro and in vivo experiments. Data from the Gene Expression Omnibus (GEO) database (GSE37147) were analyzed using weighted gene co-expression network analysis (WGCNA) and key driver analysis (KDA), and these analyses were validated using the GSE47460 dataset. The effect of CS on JunD expression was examined in lung tissues of COPD patients and CS-exposed mice and in CS extract (CSE)-exposed BEAS-2B cells. The effects of CSE on airway epithelial inflammatory injury after JunD knockdown or overexpression were also investigated. mRNA-seq and chromatin immunoprecipitation (ChIP)-seq were used to explore the mechanism of JunD-mediated CS-induced airway inflammation. Mice were injected with adeno-associated virus serotype 9 (AAV9)-JunD vector or control vector and then exposed to CS for 4 weeks, and lung tissue morphology and airway inflammation were evaluated. KDA of the lung function-related gene modules in GSE37147 revealed a potential role of JunD in COPD, which was validated in GSE47460. JunD was downregulated in lung tissues of COPD patients and CS-exposed mice and in BEAS-2B cells. JunD knockdown aggravated CSE-induced tumor necrosis factor (TNF)-α and interleukin (IL)-1β release by BEAS-2B cells, while JunD overexpression attenuated these effects. mRNA-seq and ChIP-seq identified several JunD-regulated genes, which are involved in the immune response and TNF signaling pathway and are commonly dysregulated in cell models of airway inflammation. In vivo, JunD overexpression attenuated the CS-induced inflammatory cell infiltration and inflammatory cytokine release in mouse lungs. Thus, JunD is involved in CS-induced airway inflammation and JunD-based therapy may be useful in CS-induced airway disorders.
Project description:To investigate the biochemical and genetic alterations that occur in response to cigarette smoke exposure among airway epithelial cells from different sites in the lungs, we performed microarray-based analysis using small airway epithelial cells (SAEC) and normal human bronchial epithelial cells (NHBE) following 24 h of cigarette smoke extract (CSE). In microarray-based analysis, the small airway showed higher susceptibility to CS compared to the large airway, such as enhanced expression of inflammatory-related pathways including the TNF signaling pathway. Among the TNF-related genes, PTGS2, also known as COX-2, showed the greatest difference in expression levels, with higher CSE-induced increments of both mRNA and protein expression in SAEC compared to NHBE.
Project description:Mesenchymal stem cells (MSCs) can differentiate into endothelial cells; however, the mechanisms underlying this process in the tumor microenvironment (TME) remain elusive. This study shows that tumor necrosis factor alpha (TNF-α), a key cytokine present in the TME, promotes the endothelial differentiation of MSCs by inducing vascular endothelial growth factor receptor 2 (VEGFR2) gene expression. EGR1 is a member of the zinc-finger transcription factor family induced by TNF-α. Our findings indicate that EGR1 directly binds to the VEGFR2 promoter and transactivates VEGFR2 expression. We also demonstrate that EGR1 forms a complex with c-JUN activated by c-JUN N-terminal kinase (JNK) to promote VEGFR2 transcription and endothelial differentiation in MSCs in response to TNF-α stimulation. The shRNA-mediated silencing of EGR1 or c-JUN abrogates TNF-α-induced VEGFR2 transcription and the endothelial differentiation of MSCs. Collectively, these findings demonstrate that the JNK-EGR1 signaling axis plays a crucial role in the TNF-α-induced endothelial differentiation of MSCs in the TME, which could be a potential therapeutic target for solid tumors vasculatures.
Project description:High numbers of goblet cells in airways contribute to the mucus obstruction characteristic of asthmatic airways. Allergen challenged mice exhibit robust expression of goblet cells within airway surface epithelium. This study looks at the temporal analysis of IL-13 exposed murine airways to elucidate pathways that result in differentiation of airway epithelial cells to goblet cells.
Project description:Asthma, a heterogeneous disease, is characterized by chronic inflammation, epithelial–mesenchymal transformation (EMT), and airway remodeling. After immune system activation, macrophages, T cells, and other cells gather and secrete various factors, such as interleukin-1β, 4, 5, 10, 13, and TNF-a, which break the anti-inflammatory balance and aggravate the progression of asthma. TNF-a, a member of the TNF superfamily, has promising future in the pathophysiological progress of autoimmune diseases and the development and application of related drugs. However, the mechanisms of TNF-a in mucus secretion, airway hyperreactivity, and airway remodeling of human asthma remains unclear. Tumor necrosis factor-like cytokine 1A is a type II transmembrane protein with a stable trimer structure similar to TNF-a. Migone et al. first uncovered the presence of TL1A as a membrane-bound protein (mTL1A) or a soluble protein (sTL1A) from mTL1A cleaved by an underlying enzyme. DR3 is a type I membrane protein that contains a death domain in the cytoplasmic region and remains highly homologous with other TNFRSF members. Interestingly, Evangelos et al. found that TNF-a-stimulated human lung myofibroblasts significantly increase TL1A expression and collagen production. Our study will identify the specific role of TNF-a-stimulated mTL1A/DR3 or sTL1A/DR3 axis in the EMT of asthma model.