Detailed information about stage-specific changes in gene expression is crucial for understanding the gene regulatory networks underlying development and the various signal transduction pathways contributing to morphogenesis. Here, we describe the global gene expression dynamics during early murine limb development, when cartilage, tendons, muscle, joints, vasculature, and nerves are specified and the musculoskeletal system of the limbs is established. We used whole-genome microarrays to identify genes with differential expression at 5 stages of limb development (E9.5 to 13.5), during fore-limb and hind-limb patterning. We found that the onset of limb formation is characterized by an up-regulation of transcription factors, which is followed by a massive activation of genes during E10.5 and E11.5 which tampers off at later time points. Among 3520 genes identified as significantly up-regulated in the limb, we find ~30% to be novel, dramatically expanding the repertoire of candidate genes likely to function in the limb. Hierarchical and stage-specific clustering identified expression profiles that correlate with functional programs during limb development and are likely to provide new insights into specific tissue patterning processes. Here we provide for the first time, a comprehensve analysis of developmentally regulated genes during murine limb development, and provide some novel insights into the expression dynamics governing limb morphogenesis.
Global gene expression analysis of murine limb development.
Specimen part
View SamplesPrions consist of aggregates of abnormal conformers of cellular prion protein (PrPC). They propagate by recruiting host-encoded PrPC although the critical interacting proteins and the reasons for the differences in susceptibility of distinct cell lines and populations are unknown. We derived a lineage of cell lines with markedly differing susceptibilities, unexplained by PrPC expression differences, to identify such factors. We examined the transcriptomes of prion-resistant revertants, isolated from highly susceptible cells, and identified a gene expression signature associated with susceptibility. Several of these genes encode proteins with a role in extracellular matrix (ECM) remodelling, a compartment in which disease-related PrP deposits. Loss-of-function of nine of these genes significantly increased susceptibility. Remarkably, inhibition of fibronectin 1 binding to integrin 8 by RGD peptide inhibited metalloproteinases (MMP)-2/9 whilst increasing prion propagation rates. This indicates that prion replication may be controlled by MMPs at the ECM in an integrin-dependent manner.
Identification of a gene regulatory network associated with prion replication.
Treatment
View SamplesNotch signaling is widely implicated in mouse mammary gland development and tumorigenesis. To investigate the effects of acute activation of Notch signaling in the mammary epithelial compartment, we generated bi-transgenic MMTV-rtTA; TetO-NICD1 (MTB/TICNX) mice that conditionally express a constitutively active NOTCH1 intracellular domain (NICD1) construct in the mammary epithelium upon doxycycline administration.
Notch promotes recurrence of dormant tumor cells following HER2/neu-targeted therapy.
Sex, Age, Specimen part, Treatment, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
MicroRNA-mRNA interactions in a murine model of hyperoxia-induced bronchopulmonary dysplasia.
Specimen part, Disease, Disease stage, Treatment
View SamplesRegulatory T cells (Tregs) can suppress a wide variety of cell types, in diverse organ sites and inflammatory conditions. While Tregs possess multiple suppressive mechanisms, the number required for maximal function is unclear. Furthermore, whether any inter-relationship orcross-regulatory mechanisms exist that areused to orchestrate and control their utilization is unknown. Here we assessed the functional capacity of Tregs lacking the ability to secrete both interleukin-10 (IL-10) and IL-35, which individually are required for maximal Treg activity. Surprisingly, IL-10/IL-35-double deficient Tregswere fully functionalin vitro and in vivo. Loss of IL-10 and IL-35 was compensated for by a concurrent increase in cathepsin E (CTSE) expression, enhanced TRAIL (Tnfsf10)expression and soluble TRAIL release, rendering IL-10/IL-35-double deficient Tregsfunctionally dependent on TRAIL in vitro and in vivo. Lastly, while C57BL/6 Tregs are IL-10/IL-35-dependent, Balb/c Tregs, which express high levels of CTSE and enhanced TRAIL expression, are TRAIL-dependent.These data reveal that cross-regulatory pathways exist, which control the utilization of suppressive mechanisms,thereby providing Tregfunctional plasticity.
The plasticity of regulatory T cell function.
Specimen part
View SamplesHuman and mouse blood each contain two monocyte subsets. Here, we investigated the extent of their similarity using a microarray approach. Approximately 300 genes in human and 550 genes in mouse were differentially expressed between subsets. More than 130 of these gene expression differences were conserved between mouse and human monocyte subsets. We confirmed numerous differences at the cell surface protein level. Despite overall conservation, some molecules were conversely expressed between the two species subsets, including CD36, CD9, and TREM-1. Furthermore, other differences existed, including a prominent PPAR signature in mouse monocytes absent in human. Overall, human and mouse monocyte subsets are far more broadly conserved than currently recognized. Thus, studies in mice may indeed yield relevant information regarding the biology of human monocyte subsets. However, differences between the species deserve consideration in models of human disease studied in the mouse.
Comparison of gene expression profiles between human and mouse monocyte subsets.
No sample metadata fields
View SamplesAlmost all human pancreatic ductal adenocarcinomas (PDACs) are driven by oncogenic Kras and the progression of the disease is characterized by the serial appearance of certain genetic lesions. Mouse models have convincingly shown that Kras mutation induces classical PanIN lesions that can progress to PDAC in the appropriate tumor suppressor background. However, the cooperative mechanism between mutant Kras-dependent signaling surrogates and other oncogenic pathways remains to be fully elucidated in order to devise better therapeutic strategy. Mounting evidence PTEN/PI3K perturbation on PDAC tumorigenesis, we observed frequent PTEN inactivation at both genomic and histopathological levels in primary human PDAC samples. The importance of PTEN/PI3K pathway during the development of PDAC was further supported by genetic studies demonstrating that Pten deficiency in cooperation with Kras activation accelerated the formation of invasive PDAC. Mechanistically, combined Kras mutation and Pten inactivation leads to NFkB activation and subsequent induction of cytokine pathways, accompanied with strong stromal activation and immune cell infiltration. Therefore, PTEN/PI3K pathway dictates the activity of NFkB network and serves as a major surrogate during Kras-mediated pancreatic tumorigenesis.
PTEN is a major tumor suppressor in pancreatic ductal adenocarcinoma and regulates an NF-κB-cytokine network.
Specimen part
View SamplesIn this dataset, we include the expression data obtained from KRas expressing tumors, matched Kras expressing tumor spheres, surviving cells and surviving cells after KRas re-expression for 24hs
Oncogene ablation-resistant pancreatic cancer cells depend on mitochondrial function.
Specimen part
View SamplesThe objective is to identify genes that are differentially expressed following the introduction of DNA double strand breaks (DSBs) by the Rag proteins in murine pre-B cells. Cells lacking Artemis are used since the Rag-induced DSBs will not be repaired and, thus, will provide a continuous stimulus to the cell. Cells lacking Artemis and Atm are used to determine which gene expression changes depend on Atm and cells lacking Artemis that express an I kappa B alpha dominant negative are used to determine which gene expression changes depend on NFkB.
DNA double-strand breaks activate a multi-functional genetic program in developing lymphocytes.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Combined targeting of JAK2 and Bcl-2/Bcl-xL to cure mutant JAK2-driven malignancies and overcome acquired resistance to JAK2 inhibitors.
Specimen part, Disease, Disease stage
View Samples