Airways conduct gases to the lung and are disease sites of asthma and cystic fibrosis. Here we study the cellular composition and hierarchy of the mouse tracheal epithelium by single-cell RNA-sequencing (scRNA-seq) and in vivo lineage tracing. We identify a rare cell type, the Foxi1+ pulmonary ionocyte; functional variations in club cells by proximodistal location; a distinct cell type in high turnover squamous epithelial structures that we term ''hillocks''; and disease-relevant subsets of tuft and goblet cells. We developed ''pulse-seq'' , combining scRNA-seq and lineage tracing, to show that tuft, neuroendocrine and ionocyte cells are continually and directly replenished by basal progenitor cells. Ionocytes are the major source of transcripts of the cystic fibrosis transmembrane conductance regulator in both mouse (Cftr) and human (CFTR). Knockout of Foxi1 in mouse ionocytes causes loss of Cftr expression and disrupts airway fluid and mucus physiology, phenotypes that characterize cystic fibrosis. By associating cell-type-specific expression programs with key disease genes, we establish a new cellular narrative for airways disease. Overall design: To understand normal tissue homeostasis, untreated cells were profiled using both 3''-droplet-based and full length plate-based single-cell RNAseq, in combination with genetic reporter-based lineage tracing.
A revised airway epithelial hierarchy includes CFTR-expressing ionocytes.
Specimen part, Cell line, Treatment, Subject, Time
View SamplesTechnologies allowing for specific regulation of endogenous genes are valuable for the study of gene functions and have great potential in therapeutics. We created the CRISPR-on system, a two-component transcriptional activator consisting of a nuclease-dead Cas9 (dCas9) protein fused with a transcriptional activation domain and single guide RNAs (sgRNAs) with complementary sequence to gene promoters. We demonstrate that CRISPR-on can efficiently activate exogenous reporter genes in both human and mouse cells in a tunable manner. In addition, we show that robust reporter gene activation in vivo can be achieved by injecting the system components into mouse zygotes. Furthermore we show that CRISPR-on can activate the endogenous IL1RN, SOX2, and OCT4 genes. The most efficient gene activation was achieved by clusters of 3 to 4 sgRNAs binding to the proximal promoters suggesting their synergistic action in gene induction. Significantly, when sgRNAs targeting multiple genes were simultaneously introduced into cells, robust multiplexed endogenous gene activation was achieved. Genome-wide expression profiling demonstrated high specificity of the system.
Multiplexed activation of endogenous genes by CRISPR-on, an RNA-guided transcriptional activator system.
Cell line
View SamplesWe conditionally inactivated mouse Cdx2, a dominant regulator of intestinal development, and mapped its genome occupancy in adult intestinal villi. Although homeotic transformation, observed in Cdx2-null embryos, was absent in mutant adults, gene expression and cell morphology were vitally compromised. Lethality was accelerated in mice lacking both Cdx2 and its homolog Cdx1, with exaggeration of defects in crypt cell replication and enterocyte differentiation. Cdx2 occupancy correlated with hundreds of transcripts that fell but not with equal numbers that rose with Cdx loss, indicating a predominantly activating role at intestinal cis-regulatory regions. Integrated consideration of a mutant phenotype and cistrome hence reveals the continued and distinct requirement in adults of a master developmental regulator that activates tissue-specific genes.
Essential and redundant functions of caudal family proteins in activating adult intestinal genes.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Intestinal master transcription factor CDX2 controls chromatin access for partner transcription factor binding.
Specimen part
View SamplesWe established whether partner transcription factor binding, chromatin structure, or gene expression is compromised upon loss of partner factors cdx2 or hnf4a in mouse intestinal villi
Intestinal master transcription factor CDX2 controls chromatin access for partner transcription factor binding.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gene expression signature for biliary atresia and a role for interleukin-8 in pathogenesis of experimental disease.
Specimen part, Time
View SamplesLiver biopsy samples were obtained from 64 infants with biliary atresia at the time of intraoperative cholangiogram. Liver biopsy samples were obtained from 14 age-matched infants with other causes of intrahepatic cholestasis, and from 7 deceased-donor children. GeneChip Human Gene 1.0 ST Array (Affymetrix, CA) were used to screen mRNAs whose expression was specifically regulated in the livers from patients with biliary atresia.
Gene expression signature for biliary atresia and a role for interleukin-8 in pathogenesis of experimental disease.
Specimen part
View SamplesNewborn Balb/c mice were injected intraperitoneally with 1.5x10^6 fluorescent-forming units (ffu) of type- A Rhesus Rotavirus (RRV) or 0.9% normal saline (NS; control) within 24 hours of birth to induce experimental model of biliary atresia. Extrahepatic bile ducts including gallbladder were microdissected en bloc at 3, 7 and 14 days after RRV or saline injections. GeneChip Mouse Gene 1.0 ST Array (Affymetrix, CA) were used to screen mRNAs whose expression was differently regulated after RRV challenge compared to normal saline controls.
Gene expression signature for biliary atresia and a role for interleukin-8 in pathogenesis of experimental disease.
Specimen part, Time
View SamplesThis study demonstrates simulated microgravity effects on E. coli K 12 MG1655 when grown on LB medium supplemented with glycerol. The results imply that E. coli readily reprograms itself to combat the multiple stresses imposed due to microgravity. Under these conditions it survives by upregulating oxidative stress protecting genes and simultaneously down regulating the membrane transporters and synthases to maintain cell homeostasis.
Effect of simulated microgravity on E. coli K12 MG1655 growth and gene expression.
No sample metadata fields
View SamplesCell differentiation requires epigenetic modulation of tissue-specific genes and activities of master transcriptional regulators, which are recognized for their dominant control over cellular programs. Using novel epigenomic methods, we characterized enhancer elements specifically modified in differentiating intestinal epithelial cells and found enrichment of transcription factor-binding motifs corresponding to CDX2, a master regulator of the intestine. Directed investigation revealed surprising lability in CDX2 occupancy of the genome, with redistribution from hundreds of sites occupied only in progenitors to thousands of new sites in mature cells. Knockout mice confirmed distinct Cdx2 requirements in dividing and differentiated adult intestinal cells, including responsibility for the active enhancer configuration associated with maturity. Dynamic CDX2 occupancy corresponds with condition-specific gene expression and, importantly, to differential co-occupancy with other tissue-restricted transcription factors: HNF4A in mature cells and GATA6 in progenitors. These results reveal dynamic, context-specific functions and mechanisms of a master transcription factor within a cell lineage.
Differentiation-specific histone modifications reveal dynamic chromatin interactions and partners for the intestinal transcription factor CDX2.
Specimen part, Cell line
View Samples