Porphyromonas gingivalis is a periodontal pathogen that is also associated with preterm low birth weight delivery. We investigated the transcriptional responses of human extravillous trophoblasts (HTR-8) to infection with P. gingivalis. Over 2000 genes were differentially regulated in HTR-8 cells by P. gingivalis. In ontology analyses of regulated genes, overpopulated biological pathways included MAP kinase signaling and cytokine production. Immunoblots confirmed over expression of the MAP kinase pathway components MEK3, p38 and Max. Furthermore, P. gingivalis infection induced phosphorylation and activation of MEK3 and p38. Increased production of IL-1 and IL-8 by HTR-8 cells was demonstrated phenotypically by ELISA of HTR-8 cell lysates and culture supernatants. Thus infection of trophoblasts by P. gingivalis can impact signal transduction pathways and modulate cytokine expression, outcomes that could disrupt the maintenance of pregnancy.
Human trophoblast responses to Porphyromonas gingivalis infection.
Specimen part, Cell line
View SamplesYeast filamentous growth is a stress response to conditions of nitrogen deprivation, wherein yeast colonies form pseudohyphal filaments of elongated and connected cells. As proteins mediating adhesion and transport are required for this growth transition, the protein complement at the yeast cell periphery plays a critical and tightly regulated role in enabling pseudohyphal filamentation. To identify proteins differentially abundant at the yeast cell periphery during pseudohyphal growth, we generated quantitative proteomic profiles of plasma membrane protein preparations under conditions of vegetative growth and filamentation. By iTRAQ chemistry and two-dimensional LC-MS/MS, we profiled 2,463 peptides and 356 proteins, from which we identified eleven differentially abundant proteins that localize to the yeast cell periphery. This protein set includes Ylr414cp, herein renamed Pun1p, a previously uncharacterized protein localized to the plasma membrane compartment of Can1 (MCC). Pun1p abundance is increased two-fold under conditions of nitrogen stress, and deletion of PUN1 abolishes filamentous growth in haploids and diploids; pun1D mutants are non-invasive, lack surface-spread filamentation, grow slowly, and exhibit impaired cell adhesion. Conversely, overexpression of PUN1 results in exaggerated cell elongation under conditions of nitrogen stress. PUN1 contributes to yeast nitrogen signaling, as pun1D mutants misregulate amino acid biosynthetic genes during nitrogen deprivation. By chromatin immunoprecipitation and RT-PCR, we find that the filamentous growth factor Mss11p directly binds to the PUN1 promoter and regulates its transcription. In total, this study provides the first profile of protein abundance during pseudohyphal growth, identifying a previously uncharacterized MCC protein required for wild-type nitrogen signaling and filamentous growth.
A profile of differentially abundant proteins at the yeast cell periphery during pseudohyphal growth.
No sample metadata fields
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 SamplesThe mucosal epithelium plays a key role in regulating immune homeostasis. Dysregulation of epithelial barrier function is associated with mucosal inflammation. Expression of claudin-2, a pore-forming tight junction protein, is highly upregulated during inflammatory bowel disease (IBD) and, due to its association with epithelial permeability, has been postulated to promote inflammation. Furthermore, claudin-2 also regulates colonic epithelial cell proliferation and intestinal nutrient absorption. However, the precise role of claudin-2 in regulating colonic epithelial and immune homeostasis remains unclear. Here, we demonstrate, using Villin-Claudin-2 transgenic (Cl-2TG) mice, that increased colonic claudin-2 expression unexpectedly protects mice against experimentally induced colitis and colitis-associated cancer. Notably, Cl-2TG mice exhibited increased colon length and permeability as compared with wild type (WT) littermates. However, despite their leaky colon, Cl-2TG mice subjected to experimental colitis were immune compromised, with reduced induction of TLR-2, TLR-4, Myd-88 expression and NF-kB and STAT3 activation. Most importantly, colonic macrophages in Cl-2TG mice exhibited an anergic phenotype. Claudin-2 overexpression also increased colonocyte proliferation and provided protection against colitis-induced colonocyte death. Taken together, our findings have revealed a critical role of claudin-2 in regulating colonic homeostasis, suggesting novel therapeutic strategies for inflammatory conditions of the gastrointestinal tract.
Targeted colonic claudin-2 expression renders resistance to epithelial injury, induces immune suppression, and protects from colitis.
Sex, Specimen part, Treatment
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 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 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 SamplesMegakaryocyte (MK) differentiation is well described in morphologic terms but its molecular counterparts and the basis for platelet release are incompletely understood. We profiled mRNA expression in populations of primary mouse MKs representing successive differentiation stages. Genes associated with DNA replication are highly expressed in young MKs, in parallel with endomitosis. Intermediate stages are characterized by disproportionate expression of genes associated with the cytoskeleton, cell migration and G-protein signaling, whereas terminally mature MKs accumulate hemostatic factors, including many membrane proteins. We used these expression profiles to extract a reliable panel of molecular markers for MKs of early, intermediate or advanced differentiation, and establish its value using mouse models of defective thrombopoiesis resulting from absence of GATA-1, NF-E2 or tubulin1. Computational analysis of the promoters of late-expressed MK genes identified new candidate targets for NF-E2, a critical transcriptional regulator of platelet release. One such gene encodes the kinase adaptor protein LIMS1/PINCH1, which is highly expressed in MKs and platelets and significantly reduced in NF-E2-deficient cells. Transactivation studies and chromatin immunoprecipitation implicate Lims1 as a direct target of NF-E2 regulation. Attribution of stagespecific genes, in combination with various applications, thus constitutes a powerful way to study MK differentiation and platelet biogenesis
Expression analysis of primary mouse megakaryocyte differentiation and its application in identifying stage-specific molecular markers and a novel transcriptional target of NF-E2.
No sample metadata fields
View SamplesDiverse functions of the homeodomain transcription factor BARX1 include Wnt-dependent, non-cell autonomous specification of the stomach epithelium, tracheo-bronchial septation, and Wnt-independent expansion of the spleen primordium. Tight spatio-temporal regulation of Barx1 levels in the mesentery and stomach mesenchyme suggests additional roles. To determine these functions, we forced constitutive BARX1 expression in the Bapx1 expression domain, which includes the mesentery and intestinal mesenchyme, and also examined Barx1-/- embryos in further detail. Transgenic embryos invariably showed intestinal truncation and malrotation, in part reflecting abnormal left-right patterning. Ectopic BARX1 expression did not affect intestinal epithelium, but intestinal smooth muscle developed with features typical of the stomach wall. BARX1, which is normally restricted to the developing stomach, drives robust smooth muscle expansion in this organ by promoting proliferation of myogenic progenitors at the expense of other sub-epithelial cells. Undifferentiated embryonic stomach and intestinal mesenchyme showed modest differences in mRNA expression and BARX1 was sufficient to induce much of the stomach profile in intestinal cells. However, limited binding at cis-regulatory sites implies that BARX1 may act principally through other transcription factors. Genes expressed ectopically in BARX1+ intestinal mesenchyme and reduced in Barx1-/- stomach mesenchyme include Isl1, Pitx1, Six2 and Pitx2, transcription factors known to control left-right patterning and influence smooth muscle development. The sum of evidence suggests that potent BARX1 functions in intestinal rotation and stomach myogenesis occur through this small group of intermediary transcription factors.
Control of stomach smooth muscle development and intestinal rotation by transcription factor BARX1.
Specimen part
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