Inflammatory mechanisms have been suggested to play a role in the development of heart failure (HF), but a role for chemokines is largely unknown. The aim of this study was to analyze the role of the chemokine CXCL13 and its receptor CXCR5 in cardiac pathophysiology leading to HF
Lack of chemokine signaling through CXCR5 causes increased mortality, ventricular dilatation and deranged matrix during cardiac pressure overload.
Sex, Specimen part
View SamplesDefinitive hematopoietic cells arise from hemogenic endothelium during mid-gestation, indicating a direct link between blood and the endothelial-lined vessels. We sought to determine whether mutations initiated in the hemogenic endothelium would yield hematopoietic abnormalities or malignancies. Here we demonstrate that transposon mutagenesis targeting endothelial cells in mice promotes the development of hematopoietic pathologies that are both myeloid and lymphoid in nature. Sequencing of the disrupted genes identified several previously recognized candidate cancer drivers and furthermore revealed that mutations in the lipid kinase Pi4ka can result in myeloid and erythroid dysfunction. Subsequent validation experiments showed that targeted inactivation of the Pi4ka catalytic domain or reduction in mRNA expression inhibited myeloid and erythroid cell differentiation in vitro and promoted anemia in vivo through a mechanism that includes, but it is not limited to deregulation of Akt signaling. Finally, we provide evidence linking PI4KAP2, previously considered a “pseudogene”, with human myeloid and erythroid leukemia. Overall design: mRNA transcriptional comparison between two pieces of spleen from three SBxVEC-Cre+ animals and three control animals to assess clonality of each spleen as a whole.
A Forward Genetic Screen Targeting the Endothelium Reveals a Regulatory Role for the Lipid Kinase Pi4ka in Myelo- and Erythropoiesis.
Specimen part, Cell line, Subject
View SamplesSimilar to the bone marrow, the mammary gland contains a distinct population of Hoechst-effluxing side population cells, MG-SPs. To better characterize MG-SPs, their microarray gene profiles were compared to the remaining cells, which retain Hoechst dye (MG-NSPs). For analysis, gene ontology (GO) that describes genes in terms of biological processes and ontology traverser (OT) that performs enrichment analysis were utilized. OT showed that MG-SP specific genes were enriched in the GO categories of cell cycle regulation and checkpoints, multi-drug resistant transporters, organogenesis, and vasculogenesis. The MG-NSP upregulated genes were enriched in the GO category of cellular organization and biogenesis which includes basal epithelial markers, p63, smooth muscle actin (SMA), myosin, alpha-6 integrin, cytokeratin (CK) 14, as well as luminal markers, CK8 and CD24. Additional studies showed that a higher percentage of MG-SPs exist in the G1 phase of the cell cycle compared to the MG-NSPs. G1 cell cycle block of MG-SPs may be explained by higher expression of cell cycle negative regulatory genes such as TGF-beta2 (transforming growth factor-beta2), IGFBP-5 (insulin like growth factor binding protein-5), P18 INK4C and Wnt-5a (wingless-5a). Accordingly, a smaller percentage of MG-SPs expressed nuclear b-catenin, possibly as a consequence of the higher expression of Wnt-5a. In conclusion, microarray gene profiling suggests that MG-SPs are a lineage deficient mammary gland sub-population expressing key genes involved in cell cycle regulation, development and angiogenesis.
Transcriptional profiling of mammary gland side population cells.
No sample metadata fields
View SamplesThis series of samples comprises multiple early embryonic time courses for C. elegans. Time courses consisting of 10 time points each for 4 different genotypes are included: wild-type (strain N2 grown on E. coli strain OP50), pie-1(zu154) (progeny of homozygous mutant mothers [Unc] of strain JJ532 grown on E. coli strain OP50), pie-1(zu154);pal-1(RNAi) (progeny of homozygous mutant mothers [Unc] of strain JJ532 grown on E. coli strain HT115 expressing pal-1 hairpin RNA), and mex-3(zu155);skn-1(RNAi) (progeny of homozygous mutant mothers [Dpy] of strain JJ518 grown on E. coli strain HT115 expressing skn-1 hairpin RNA). Embryos were manually staged by morphology at the 4-cell stage and allowed to develop in water for defined amounts of time at 22 degrees C. RNA was amplified as described (Baugh et al. Development, 2003; Baugh et al. Nucleic Acids Research, 2001). This series of samples comprises all replicate data reported by Baugh et al. (Development, 2005).
The homeodomain protein PAL-1 specifies a lineage-specific regulatory network in the C. elegans embryo.
No sample metadata fields
View SamplesSubstantial evidence implicates IGF-I signaling in the development and progression of breast cancer. To identify transcriptional targets of IGF action in breast cancer cells, we performed gene expression profiling (>22,000 RNA transcripts) of IGF-I-stimulated MCF-7 cells, a well characterized breast cancer cell line that is highly responsive to IGFs. We defined an IGF-I gene signature pattern of hundreds of genes either up-regulated or down-regulated at both 3 and 24 hrs in vitro. After removing genes considered generic to cell proliferation, the signature was examined in four different public profile datasets of clinical breast tumors (representing close to 1000 patients), as well as in profile datasets of experimental models for various oncogenic signaling pathways. Genes with early and sustained regulation by IGF-I were highly enriched for transcriptional targets of the estrogen, Ras, and PI3K/Akt/mTOR pathways. The IGF-I signature appeared activated in most estrogen receptor-negative (ER-) clinical breast tumors and in a substantial subset (~25%) of ER+ breast tumors. Patients with tumors showing activation of the IGF-I signature tended to have a shorter time to disease recurrence (including patients not receiving adjuvant therapy), both when considering all patients and the subset of ER+ patients. We found evidence for cross-talk and common transcriptional endpoints between the IGF-I and estrogen systems. Our results support the idea that the IGF-I pathway is one mechanism by which breast tumors may acquire hormone independence and a more aggressive phenotype.
Insulin-like growth factor-I activates gene transcription programs strongly associated with poor breast cancer prognosis.
No sample metadata fields
View SamplesTo investigate molecular mechanisms of resistance, we used two different in vivo xenograft models of estrogen receptor-positive (ER+) breast cancer, with or without HER2 over-expression (MCF7/HER2-18 and MCF7 wt, respectively). Mice with established tumors were assigned to the following treatment groups: continued estrogen supplementation (E2), estrogen deprivation (ED), ED plus tamoxifen (Tam), all with or without the EGFR tyrosine kinase inhibitor gefinitinib (G). Another group received ED plus the antiestrogen fulvestrant (MCF7 wt only). Tumors with acquired or de novo resistance to these endocrine therapies were profiled for mRNA expression using Affymetrix Genechip arrays.
Development of resistance to targeted therapies transforms the clinically associated molecular profile subtype of breast tumor xenografts.
No sample metadata fields
View SamplesTo investigate molecular mechanisms of resistance, we used two different in vivo xenograft models of estrogen receptor-positive (ER+) breast cancer, with or without HER2 over-expression (MCF7/HER2-18 and MCF7 wt, respectively). Mice with established tumors were assigned to the following treatment groups: continued estrogen supplementation (E2), estrogen deprivation (ED), ED plus tamoxifen (Tam), all with or without the EGFR tyrosine kinase inhibitor gefinitinib (G). Another group received ED plus the antiestrogen fulvestrant (MCF7 wt only). Tumors with acquired or de novo resistance to these endocrine therapies were profiled for mRNA expression using Affymetrix Genechip arrays.
Development of resistance to targeted therapies transforms the clinically associated molecular profile subtype of breast tumor xenografts.
No sample metadata fields
View SamplesTo investigate molecular mechanisms of resistance, we used two different in vivo xenograft models of estrogen receptor-positive (ER+) breast cancer, with or without HER2 over-expression (MCF7/HER2-18 and MCF7 wt, respectively). Mice with established tumors were assigned to the following treatment groups: continued estrogen supplementation (E2), estrogen deprivation (ED), ED plus tamoxifen (Tam), all with or without the EGFR tyrosine kinase inhibitor gefinitinib (G). Another group received ED plus the antiestrogen fulvestrant (MCF7 wt only). Tumors with acquired or de novo resistance to these endocrine therapies were profiled for mRNA expression using Affymetrix Genechip arrays.
Development of resistance to targeted therapies transforms the clinically associated molecular profile subtype of breast tumor xenografts.
No sample metadata fields
View SamplesHedgehog (Hh) signaling is critical for organogenesis, tissue homeostasis, and stem cell maintenance. Smoothened (SMO), the primary effector of Hh signaling, is expressed ectopically in human breast cancer, as well as in other cancers. Constitutive activation of SMO in mouse mammary glands leads to paracrine stimulation of proliferation, as well as hyperplasia. In canonical signaling, SMO functions via GLI transcription factor activation. However, recent data from Drosophila and mammalian cell lines indicate that SMO can function non-canonically as a G-protein coupled receptor (GPCR) by coupling to heterotrimeric G proteins, particularly those in the pertussis toxin (PTX)-sensitive G-alpha-i (Gai) class. Whether SMO functions as a GPCR in mammalian tissues in vivo is not known. Using genetically modified mouse models, we demonstrate here that SMO-induced stimulation of proliferation is PTX sensitive, and requires Gai2, but not Gai1 or Gai3. Our findings provide evidence for a non-canonical GPCR function of activated SMO in vivo, a finding that may have clinical significance given that most SMO-targeted agents were selected based largely on their ability to block canonical GLI-mediated transcription. Overall design: Primary mammary epithelial cell RNA was deep-sequenced from mT-mG/SmoM2;MMTV-Cre (EGFP), mT-mG/SmoM2;MMTV-Cre (tdTomato), and mT-mG/SmoM2;+ cells to examine the effects of SmoM2 overexpression in the mammary gland.
An essential role for Gα(i2) in Smoothened-stimulated epithelial cell proliferation in the mammary gland.
No sample metadata fields
View SamplesE47 represses Foxp3 transcription, albeit indirectly through the activation of unknown negative regulatory of Foxp3 transcription.
Id3 Maintains Foxp3 Expression in Regulatory T Cells by Controlling a Transcriptional Network of E47, Spi-B, and SOCS3.
Age, Specimen part
View Samples