Project description:We performed RNA sequencing of gene expression of differentiated primary human bronchial epithelial cells derived from control and asthmatic patients, stimulated with IL-13. The Type 2 Asthma mediator IL-13 was described to induce airway hyperresponsiveness, goblet cell metaplasia, mucus hypersecretion and airway remoddeling including impairment of epithelial barrier integrity. We investigated differential expression of SARS-CoV-2 related host gene expression as well as genes involved in N-linked glycosylation upon IL-13 in bronchial epithelial cells. Top IL-13 affected pathways included ion- and transmembrane transport, lipid metabolic processed and protein glycosylation.
Project description:Primary culture airway epithelial cells, grown under physiologic air-liquid interface conditions, with, or without IL-13 in order to study the effects of this cytokine on mucous cell metaplasia, an important feature of asthma and COPD. Keywords: IL13, mucus, goblet cell RNA was isolated from primary culture airway epithelial cells grown at air-liquid interface, treated with or without IL-13 for 21 days.
Project description:Human airway epithelia (HAE) undergo inflammation-induced remodeling in chronic lung diseases such as asthma and chronic bronchitis. The role of type 2 inflammation-induced epithelial remodeling in SARS-CoV-2 infection and the course of COVID-19 is unclear, moreover, there is discrepancy in the literature regarding the potential benefit of treatments that modulate type 2 inflammation. We investigated the role of IL-13-induced inflammation on SARS-CoV-2 binding/entry, replication, and host response in primary HAE cells in vitro and in a model of mouse-adapted SARS-CoV-2 in vivo. IL-13 protected airway epithelial cells from SARS-CoV-2 infection in vitro by decreasing the abundance of ACE2- expressing ciliated cells rather than by neutralization in the airway surface liquid or by interferon-mediated antiviral effects. In contrast, IL-13 worsened the severity of disease in mice in vivo; the effects were mediated by eicosanoid signaling and were abolished in mice deficient in the phospholipase A2 enzyme PLA2G2D. We conclude that IL-13-induced inflammation affects multiple steps of SARS-CoV-2-induced disease pathogenesis. Whereas IL-13-induced inflammation may be protective against initial infection at the airway epithelium, it enhances disease severity once infection progresses in vivo; blockade of IL-13 and/or eicosanoid signaling may be protective against progression to severe lung disease.
Project description:BACKGROUND: The type 2 cytokine-high asthma endotype (T2H) is characterized by IL-13-driven mucus obstruction of the airways. To investigate this poorly understood pathobiology, we characterized IL-13 effects on human airway epithelial cultures using single cell RNA-sequencing, finding that IL-13 generated a novel transcriptional state for each cell type. Specifically, we discovered a mucus secretory program induced by IL-13 in all cell types which converted both mucus and defense secretory cells into a metaplastic state with emergent mucin production and secretion, while leading to ER stress and cell death in ciliated cells. The IL-13-remodeled epithelium secreted a pathologic, mucin-imbalanced, and innate immunity-depleted proteome that arrested mucociliary motion. Signatures of IL-13-induced cellular remodeling were mirrored by transcriptional signatures characteristic of the nasal airway epithelium within T2H versus T2-low asthmatic children. Our results reveal the epithelium-wide scope of T2H asthma and present novel therapeutic targets for restoring normal epithelial function.
Project description:Selective stimulation of IL-4 receptor on smooth muscle induces airway hyper-responsiveness in mice. Abstract: Production of the cytokines IL-4 and IL-13 is increased in both human asthma and mouse asthma models and Stat6 activation by the common IL-4/IL-13R drives most mouse model pathophysiology, including airway hyperresponsiveness (AHR). However, the precise cellular mechanisms through which IL-4Rα induces AHR remain unclear. Overzealous bronchial smooth muscle constriction is thought to underlie AHR in human asthma, but the smooth muscle contribution to AHR has never been directly assessed. Furthermore, differences in mouse vs. human airway anatomy and observations that selective IL-13 stimulation of Stat6 in airway epithelium induces murine AHR raise questions about the importance of direct IL-4R effects on smooth muscle in murine asthma models and relevance of these models to human asthma. Using transgenic mice in which smooth muscle is the only cell type that expresses or fails to express IL-4Rα, we demonstrate that direct smooth muscle activation by IL-4, IL-13, or allergen is sufficient, but not necessary, to induce AHR and show that 5 genes known to promote smooth muscle migration, proliferation and contractility are activated by IL-13 in smooth muscle in vivo. These observations demonstrate that IL-4Rα promotes AHR through multiple mechanisms and provide a model for testing smooth muscle-directed asthma therapeutics.
Project description:Primary culture airway epithelial cells, grown under physiologic air-liquid interface conditions, with, or without IL-13 in order to study the effects of this cytokine on mucous cell metaplasia, an important feature of asthma and COPD. Keywords: IL13, mucus, goblet cell
Project description:Introgressed variants from other species can be an important source of genetic variation because they may arise rapidly, can include multiple mutations on a single haplotype, and have often been pretested by selection in the species of origin. Although introgressed alleles are generally deleterious, several studies have reported introgression as the source of adaptive alleles-including the rodenticide-resistant variant of Vkorc1 that introgressed from Mus spretus into European populations of Mus musculus domesticus. Here, we conducted bidirectional genome scans to characterize introgressed regions into one wild population of M. spretus from Spain and three wild populations of M. m. domesticus from France, Germany, and Iran. Despite the fact that these species show considerable intrinsic postzygotic reproductive isolation, introgression was observed in all individuals, including in the M. musculus reference genome (GRCm38). Mus spretus individuals had a greater proportion of introgression compared with M. m. domesticus, and within M. m. domesticus, the proportion of introgression decreased with geographic distance from the area of sympatry. Introgression was observed on all autosomes for both species, but not on the X-chromosome in M. m. domesticus, consistent with known X-linked hybrid sterility and inviability genes that have been mapped to the M. spretus X-chromosome. Tract lengths were generally short with a few outliers of up to 2.7 Mb. Interestingly, the longest introgressed tracts were in olfactory receptor regions, and introgressed tracts were significantly enriched for olfactory receptor genes in both species, suggesting that introgression may be a source of functional novelty even between species with high barriers to gene flow.
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other