Project description:Purpose: Tracheal epithelial brush cells are rare chemosensory cells defined by their expression of elements of the bitter taste transduction system, and known to activate the cholinergic nervous system in the murine lung. Similar chemosensory cells in the intestine can generate lipid mediators and pro-inflammatory cytokines but whether brush cell can contribute to airway inflammation is unknown. Furthermore, despite the advances in understanding chemosensory cell effector functions, the receptors that mediate chemosensory cell activation and expansion beyond taste receptors in any compartment remain largely unknown. Methods: In this study, we isolated tracheal brush cells by FACS from naïve ChATBAC-eGFP mice with knockin of eGFP within a BAC spanning the acetylcholine transferase locus, marking brush cells in the epithelium and performed transcriptome profiling using low input RNA sequencing. We compared tracheal brush cells to EpCAM+ epithelial cells and CD45+ hematopoetic cells in naive mice. Results: When compared to EpCAM+ EpCs and to CD45+ cells in the airway, principal component analysis demonstrated that brush cells grouped quite distinctly. This brush cell distinction relative to EpCAM+ cells, was further reflected in the striking number of highly differentially expressed genes. This included 1305 genes expressed at 4-fold or higher levels in EpCAM+eGFP+ cells (brush cells), of which 418 genes were expressed at 32-fold or higher levels in brush cells. Conclusions: Our study represents the first detailed analysis of the transcriptome of tracheal brush cells and identifies a unique set of genes that are primarily expressed in brush cells including the bitter taste transduction system, synthenic machinery for several pro-inflammatory lipid mediators and HoxA2 transciptional factors.
Project description:Purpose: Choline acetyltransferase (ChAT)-expressing epithelial cells are found in the upper and lower airways. In the trachea, they are referred to as brush cells. In the mouse nose two distinct populations of ChAT-eGFP+ cells had been previously described: a population of rare solitary chemosensory cells (SCCs) in the respiratory mucosa and a more abundant population of microvillous cells (MVCs) in the olfactory epithelium. Besides ChAT expression, SCCs share the expression of bitter taste receptors and signaling machinery with tracheal brush cells as well as close association with CGPR+ nerve fibers and an elongated shape. MVCs do not express bitter taste receptors, are not clearly associated with nerves and are smaller in size than SCCs. We have previously reported the transcriptional profile of tracheal ChAT-expressing brush cells but the transcriptional profile of nasal chemosensory ChAT+ epithelial cells has not been reported. Methods: In this study, we isolated nasal ChAT-eGFP+ cells by FACS from naïve ChAT(BAC)-eGFP mice with knockin of eGFP within a BAC spanning the ChAT locus, marking brush cells in the epithelium and performed transcriptome profiling using low input RNA sequencing. We sorted two distinct subsets of ChAT-eGFP+ epithelial cells from the nasal mucosa based on FACS ice and granularity characteristic: ChAT-eGFP+ EpCAM+ FSC/SSChigh (representing 5% of all ChAT-eGFP+ cells) and FSC/SSClow (representing 95% of all ChAT-eGFP+ cells), respectively. We compared them to unfractionated ChAT-eGFP- EpCAM+ epithelial cells. Results: Both nasal ChAT-eGFP subsets shared the core transcriptional profile of chemosensory cells from the intestine, trachea, gallbladder and thymus including the expression of Il25, Pou2f3, Trpm5, Avil, Plcb2 and transcripts of eicosanoid biosynthetic enzymes suggesting that most ChAT-eGFP+ cells in the nose belong to the chemosensory/tuft/brush cel family. The two subsets of nasal ChAT-eGFP+ cells differed in expression of taste receptors and taste receptor signaling machinery. Conclusions: Our study represents the first detailed analysis of the transcriptome of nasal ChAT-eGFP+ cells (brush cells) and identifies two subsets of nasal brush cells that share a core transcriptional signature but differ in expression of bitter taste receptors.
Project description:iTRAQ-based comparison of proteins derived from oral cells collected by brush biopsy. Protein abundance levels compared between oral pre-malignant cells, oral cancer cells and healthy normal cells, all collected from human patients. Two separate iTRAQ labeled biological replicate analyses were conducted.
Project description:Abstract: The Drosophila trachea is a branched tubular epithelia that transports oxygen and other gases. trachealess (trh), which encodes a bHLH-PAS transcription factor, is among the first genes to be expressed in the cells that will form the trachea. In the absence of trh, tracheal cells fail to invaginate to form tubes and remain on the embryo surface. Expression of many tracheal-specific genes depends on trh, but all of the known targets have relatively minor phenotypes compared to loss of trh, suggesting that there are additional targets. To identify uncharacterized transcriptional targets of Trh and to further understand the role of Trh in embryonic tracheal formation, we performed an in situ hybridization screen using a library of ~100 tracheal-expressed genes identified by the Berkeley Drosophila Genome Project (BDGP). Surprisingly, expression of every tracheal gene we tested was dependent on Trh, suggesting a major role for Trh in activation and maintenance of tracheal gene expression. A re-examination of the interdependence of the known early-expressed transcription factors, including trh, ventral veinless (vvl) and knirps/knirps-related (kni/knrl), suggests a new model for how gene expression is controlled in the trachea, with trh regulating expression of vvl and kni, but not vice versa. A pilot screen for the targets of Vvl and Kni/Knrl revealed that Vvl and Kni have only minor roles compared to Trh. Finally, genome-wide microarray experiments identified additional Trh targets and revealed that a of biological processes are affected by the loss of trh. Goals: The goals of the microarray experiments were to identify additional targets of the Trh transcription factor to learn the range of genes regulated by this transcription factor during embryogenesis. Our in situ screen revealed that Trh is required for all tested tracheal genes. Our new data now shows that Trh affects a range of biological processes.
Project description:The study aimed to compare the gene expression profiles at a single cell level in bronchial brush cells between patients with idiopathic pulmonary fibrosis and disease controls.
Project description:Abstract: The Drosophila trachea is a branched tubular epithelia that transports oxygen and other gases. trachealess (trh), which encodes a bHLH-PAS transcription factor, is among the first genes to be expressed in the cells that will form the trachea. In the absence of trh, tracheal cells fail to invaginate to form tubes and remain on the embryo surface. Expression of many tracheal-specific genes depends on trh, but all of the known targets have relatively minor phenotypes compared to loss of trh, suggesting that there are additional targets. To identify uncharacterized transcriptional targets of Trh and to further understand the role of Trh in embryonic tracheal formation, we performed an in situ hybridization screen using a library of ~100 tracheal-expressed genes identified by the Berkeley Drosophila Genome Project (BDGP). Surprisingly, expression of every tracheal gene we tested was dependent on Trh, suggesting a major role for Trh in activation and maintenance of tracheal gene expression. A re-examination of the interdependence of the known early-expressed transcription factors, including trh, ventral veinless (vvl) and knirps/knirps-related (kni/knrl), suggests a new model for how gene expression is controlled in the trachea, with trh regulating expression of vvl and kni, but not vice versa. A pilot screen for the targets of Vvl and Kni/Knrl revealed that Vvl and Kni have only minor roles compared to Trh. Finally, genome-wide microarray experiments identified additional Trh targets and revealed that a of biological processes are affected by the loss of trh. Goals: The goals of the microarray experiments were to identify additional targets of the Trh transcription factor to learn the range of genes regulated by this transcription factor during embryogenesis. Our in situ screen revealed that Trh is required for all tested tracheal genes. Our new data now shows that Trh affects a range of biological processes. RNA was isolated from stage 11-16 wild type Drosophila embryos and compared to RNA from trh null mutant embryos of the same age; all samples were hybridized to the Drosophila Genome 2.0 Affymetrix array. Three individual replicates were obtained for each sample.
Project description:We provide an original multi-stage approach identifying a gene signature to assess the fibroblast polarization. Prototypic polarizations (inflammatory/fibrotic) were induced by seeded mouse embryonic fibroblasts (MEFs) with TNFα or TGFß1, respectively. The transcriptomic and proteomic profiles were obtained by RNA microarray and LC/MS-MS. Gene Ontology and pathways analysis were performed among the differentially expressed genes (DEGs) and proteins (DEPs). Balb/c mice underwent daily intradermal injections of HOCl (or PBS) as an experimental murine model of inflammation-mediated fibrosis in a time-dependent manner. As results, 1,456 and 2,215 DEGs, and 289 and 233 DEPs were respectively found in MEFs in response to TNFα or TGFß1, respectively. Among the most significant pathways, we combined 26 representative genes to encompass the proinflammatory and profibrotic polarizations of fibroblasts. Based on principal component analysis, this signature deciphered baseline state, proinflammatory polarization, and profibrotic polarization as accurately as did RNA microarray and LC/MS-MS. Then, we assessed the gene signature on dermal fibroblasts isolated from the experimental murine model. We observed a proinflammatory polarization at day 7, and a mixture of a proinflammatory and profibrotic polarizations at day 42 in line with histological findings. Our approach provides a small-size and convenient gene signature to assess murine fibroblast polarization.