The goal of this experiment was to determine gene expression changes during influenza A virus infection as the result of expression influenza virus inducible miRNAs in A549 cells.
Small RNA profiling of influenza A virus-infected cells identifies miR-449b as a regulator of histone deacetylase 1 and interferon beta.
Cell lineView Samples
The Wnt signaling pathway plays a fundamental role during the development of metazoans, where it functions in the regulation of diverse processes including cell fate specification, cell migration, and stem cell renewal. Activation of the beta-catenin dependent or canonical Wnt signaling pathway upregulates expression of Wnt target genes to mediate an appropriate cellular response. In the nematode C. elegans, a Wnt signaling pathway similar to the canonical pathway regulates several processes during larval development, however few target genes of this pathway have been identified. To address this deficit, we conditionally activated Wnt signaling in living animals during a defined stage of larval life by expressing a dominant, activated beta-catenin protein, then used microarray analysis to identify genes showing altered expression compared to control animals. In this way we identified 166 differentially expressed genes, of which 104 were upregulated. A subset of the upregulated genes were validated by qPCR and showed altered expression in Wnt pathway mutants with decreased or increased Wnt signaling; we consider these genes to be candidate Wnt pathway targets in the C. elegans hermaphrodite larva. Amongst these was a group of 6 genes, including the cuticular collagen genes, bli-1 col-38, col-49 and col-71, that show a peak of expression in the mid L4 stage during normal development. The L4 expression of these genes suggests they may be expressed for use in the adult cuticle, and consistent with this, reduction of function for several of the genes leads to phenotypes suggestive of defects in cuticle function or integrity. Therefore this work has identified a large number of putative Wnt pathway target genes during larval life, including a small subset of Wnt-regulated collagen genes that may function in synthesis of the adult cuticle.
Use of an activated beta-catenin to identify Wnt pathway target genes in caenorhabditis elegans, including a subset of collagen genes expressed in late larval development.
No sample metadata fieldsView Samples
Canonical Wnt signaling controls proliferation and differentiation of osteogenic progenitor cells, and tumor-derived secretion of the Wnt antagonist Dickkopf-1 (Dkk1) is correlated with osteolyses and metastasis in many bone malignancies. However, the role of Dkk1 in the oncogenesis of primary osteosarcoma (OS) remains unexplored. Here, we over-expressed Dkk1 in the OS cell line MOS-J. Contrary to expectations, Dkk1 had autocrine effects on MOSJ cells in that it increased proliferation and resistance to metabolic stress in vitro. In vivo, Dkk1 expressing MOS-J cells formed larger and more destructive tumors than controls. These effects were attributed in part to up-regulation of the stress response enzyme and cancer stem cell marker aldehyde-dehydrogenase-1 (ALDH1) through Jun-N-terminal kinase signaling. This is the first report linking Dkk1 to tumor stress resistance, further supporting the targeting of Dkk1 not only to prevent and treat osteolytic bone lesions but also to reduce numbers of stress-resistant tumor cells.
An unexpected role for a Wnt-inhibitor: Dickkopf-1 triggers a novel cancer survival mechanism through modulation of aldehyde-dehydrogenase-1 activity.
Specimen part, Cell lineView Samples
Dysfunction of the cystic fibrosis transmembrane regulator (CFTR) in cystic fibrosis (CF) results in exaggerated and chronic inflammation as well as increased susceptibility to chronic pulmonary infections, in particular with Pseudomonas aeruginosa. Based on the concept that host immune responses do not seem to be adequate to eradicate P.aeruginosa from the lungs of CF patients and that dendritic cells (DC) play an important role in initiating and shaping adaptive immune responses, this study analyzed the role of CFTR in bone marrow-derived murine DC from CFTR knockout (CF) mice with and without exposure to P.aeruginosa. DC expressed CFTR mRNA and protein, although at much lower levels compared to whole lung. Microarray analysis of gene expression levels in DC generated from CF and wild type (WT) mice revealed significantly different expression of 16 genes in CF DC compared to WT DC. Among the genes with lower expression in CF DC was Caveolin-1, a membrane lipid raft protein. Messenger RNA and protein levels of Caveolin-1 were decreased in the CF DC compared to WT DC. Consistently, the active form of sterol-responsive element binding protein (SREBP), a negative regulator of Caveolin-1 expression, was increased in CF DC. Following exposure to P.aeruginosa, gene expression levels in CF and WT DC changed for 912 genes involved in inflammation, chemotaxis, signaling, cell cycling and apoptosis more than 1.5-fold. Among the genes that showed a different response between WT and CF DC infected with P.aeruginosa, were 3-hydroxysterol-7 reductase (Dhcr7) and stearoyl-CoA desaturase 2 (Scd2), two enzymes involved in the lipid metabolism that are also regulated by SREBP. These results suggest that CFTR dysfunction in non-epithelial cells results in changes in the expression of genes encoding factors involved in membrane structure and lipid-metabolism. These membrane alterations in immune cells may contribute to the abnormal inflammatory and immune response characteristic of CF.
Influence of the cystic fibrosis transmembrane conductance regulator on expression of lipid metabolism-related genes in dendritic cells.
No sample metadata fieldsView Samples
The roundworm Caenorhabditis elegans is a heme auxotroph that requires the coordinated actions of HRG-1 heme permeases to transport environmental heme into the intestine and HRG-3, a secreted protein, to deliver intestinal heme to other tissues including the embryo. Here we show that heme homeostasis in the extraintestinal hypodermal tissue is facilitated by the transmembrane protein HRG-2. Systemic heme deficiency upregulates hrg-2 mRNA expression over 200-fold in the main body hypodermal syncytium hyp 7. HRG-2 is a type I membrane protein which binds heme and localizes to the endoplasmic reticulum and apical plasma membrane. Cytochrome heme profiles are aberrant in HRG-2 deficient worms, a phenotype that is partially suppressed by heme supplementation. Heme-deficient yeast strain, ectopically expressing worm HRG-2, reveal significantly improved growth at submicromolar concentrations of exogenous heme. Taken together, our results implicate HRG-2 as a facilitator of heme utilization in the C. elegans hypodermis and provide a mechanism for regulation of heme homeostasis in an extraintestinal tissue.
Heme utilization in the Caenorhabditis elegans hypodermal cells is facilitated by heme-responsive gene-2.
No sample metadata fieldsView Samples
We compared splenic Va14i NKT cells from C57BL/6 control mice and from mice injected 4 weeks earlier intravenously with 4ug/mouse of the iNKT cell antigen alpha-galactosylceramide (aGalCer). These mice were either left unstimulated or were stimulated with 1ug/mouse aGalCer i.v.. All mice were female and 8 weeks of age at the beginning of the experiment. Va14i NKT cells were enriched via magnetic selection and cell sorted for TCRb+ CD1d/aGalCer-tetramer+. Total RNA were prepared using a Qiagen RNeasy mini kit. IVT probe generation and hybridization to Affymetrix Mouse Genome 430 2.0 arrays was carried out by the Veterans Medical Research Foundation GeneChipTM Microarray located at UCSD.
IL-10-producing NKT10 cells are a distinct regulatory invariant NKT cell subset.
Sex, Age, Specimen part, TreatmentView Samples
Silencing HoxA1 in vivo by intraductal delivery of nanoparticle-formulated siRNA reduced mammary tumor incidence by 75% , reduced cell proliferation, and prevented loss of ER and PR expression.
Silencing HoxA1 by intraductal injection of siRNA lipidoid nanoparticles prevents mammary tumor progression in mice.
Age, Specimen partView Samples
Mononuclear phagocytes play an important role in the removal of apoptotic cells by expressing cell surface receptors that recognize and remove apoptotic cells. Based on the knowledge that cigarette smoking is associated with increased lung cell turnover, we hypothesized that alveolar macrophages (AM) of normal cigarette smokers may exhibit enhanced expression of apoptotic cell removal receptor genes. AM obtained by bronchoalveolar lavage of normal non-smokers (n=11) and phenotypic normal smokers (n=13, 36 6 pack-yr) were screened for mRNA expression of all known apoptotic cell removal receptors using Affymetrix HG-U133 Plus 2.0 chips with TaqMan RT-PCR confirmation. Of the 14 known apoptotic receptors expressed, only MER Tyrosine Kinase (MERTK), a transmembrane tyrosine kinase receptor, was significantly up-regulated in smokers. MERTK expression was then assessed in AM of smokers vs nonsmokers by TaqMan RT-PCR, immunohistochemistry, Western and flow analysis. Smoker AM had up-regulation of MERTK mRNA levels (smoker vs non-smoker, 3.6-fold by microarray, p<0.003; 9.5-fold by TaqMan RT-PCR, p<0.02). Immunohistochemistry demonstrated a qualitative increase in MERTK protein expression on AM of smokers. Increased protein expression of MERTK on AM of smokers was confirmed by Western and flow analyses (p< 0.007 and p< 0.0002, respectively). MERTK, a cell surface receptor that recognizes apoptotic cells, is expressed on human AM, and its expression is up-regulated in AM of cigarette smokers. This may reflect an increased demand for removal of apoptotic cells in smokers, an observation with implications for the development of chronic obstructive pulmonary disease (COPD), a disorder associated with dysregulated apoptosis of lung parenchymal cells.
Overexpression of apoptotic cell removal receptor MERTK in alveolar macrophages of cigarette smokers.
Sex, AgeView Samples
The evolutionarily conserved Wnt/?-catenin signaling pathway plays a fundamental role during metazoan development, regulating numerous processes including cell fate specification, cell migration, and stem cell renewal. Wnt ligand binding leads to stabilization of the transcriptional effector ?-catenin and upregulation of target gene expression to mediate a cellular response. During larval development of the nematode Caenorhabditis elegans, Wnt/?-catenin pathways act in fate specification of two hypodermal cell types, the ventral vulval precursor cells (VPCs) and the lateral seam cells. Because little is known about targets of the Wnt signaling pathways acting during larval VPC and seam cell differentiation, we sought to identify genes regulated by Wnt signaling in these two hypodermal cell types. We conditionally activated Wnt signaling in larval animals and performed cell type?specific "mRNA tagging" to enrich for VPC and seam cell?specific mRNAs, and then used microarray analysis to examine gene expression compared to control animals. Two hundred thirty-nine genes activated in response to Wnt signaling were identified, and we characterized 50 genes further. The majority of these genes are expressed in seam and/or vulval lineages during normal development, and reduction of function for nine genes caused defects in the proper division, fate specification, fate execution, or differentiation of seam cells and vulval cells. Therefore, the combination of these techniques was successful at identifying potential cell type?specific Wnt pathway target genes from a small number of cells and at increasing our knowledge of the specification and behavior of these C. elegans larval hypodermal cells.
Identification of Wnt Pathway Target Genes Regulating the Division and Differentiation of Larval Seam Cells and Vulval Precursor Cells in Caenorhabditis elegans.
Specimen partView Samples
NHR-23, a conserved member of the nuclear receptor family of transcription factors, is required for normal development in C. elegans where it plays a critical role in growth and molting. In a search for NHR-23 dependent genes, we performed whole genome comparative expression microarrays on both control and nhr-23 inhibited synchronized larvae. Genes that decreased in response to nhr-23 RNAi included several collagen genes. Unexpectedly, several hedgehog-related genes were also down-regulated after nhr-23 RNAi. A homozygous nhr-23 deletion allele was used to confirm the RNAi knockdown phenotypes and the changes in gene expression. Our results indicate that NHR-23 is a critical coregulator of functionally linked genes involved in growth and molting and reveal evolutionary parallels among the ecdysozoa.
NHR-23 dependent collagen and hedgehog-related genes required for molting.
Specimen partView Samples