Toxin A (TcdA) and Toxin B (TcdB), of the pathogen Clostridium difficile, are virulence factors that cause gross pathologic changes (e.g. inflammation, secretion, and diarrhea) in the infected host, yet the molecular and cellular pathways leading to observed host responses are poorly understood. To address this gap, TcdA and/or TcdB were injected into the ceca of mice and the genome-wide transcriptional response of epithelial layer cells was examined. Bioinformatic analysis of gene expression identified sets of cooperatively expressed genes. Further analysis of inflammation associated genes revealed dynamic chemokine responses.
In vivo physiological and transcriptional profiling reveals host responses to Clostridium difficile toxin A and toxin B.
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View SamplesWnt signaling is intrinsic to mouse embryonic stem cell self-renewal. Therefore it is surprising that reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) is not strongly enhanced by Wnt signaling. Here, we demonstrate that active Wnt signaling inhibits the early stage of reprogramming to iPSCs, while it is required and even stimulating during the late stage. Mechanistically, this biphasic effect of Wnt signaling is accompanied by a change in the requirement of all four of its transcriptional effectors: Tcf1, Lef1, Tcf3, and Tcf4. For example, Tcf3 and Tcf4 are stimulatory early but inhibitory late in the reprogramming process. Accordingly, ectopic expression of Tcf3 early in reprogramming combined with its loss-of-function late enables efficient reprogramming in the absence of ectopic Sox2. Together, our data indicate that the step-wise process of reprogramming to iPSCs is critically dependent on the stage-specific control and action of all four Tcfs and Wnt signaling.
Stage-specific regulation of reprogramming to induced pluripotent stem cells by Wnt signaling and T cell factor proteins.
Specimen part, Time
View SamplesThe Melanoma-associated Antigen gene family (MAGE) generally encodes for tumour antigens. We recently have identified one of the MAGE gene members, Mageb16 to be highly expressed in undifferentiated murine embryonic stem cells (mESCs). The role of Mageb16 for the differentiation of the pluripotent stem cells is completely unknown. Here we demonstrate that Mageb16 (41 kDa) is distributed in cytosol and/or in surface membrane in undifferentiated mESCs. A transcriptome study was performed with differentiated short hairpin RNA (shRNA)-mediated Mageb16 knockdown (KD ESCs) and scrambled control (SCR) ESCs until a period of 22 days. Mageb16 KD ESCs mainly differentiated towards mesodermal derivatives such as cardiovascular lineages. Mesoderm-oriented differentiation initiated biological processes such as adipogenesis, osteogenesis, limb morphogenesis and spermatogenesis were significantly enriched in the differentiated Mageb16 KD ESCs. Cardiomyogenesis in differentiated KD mESCs was stronger when compared to differentiated SCR and wild mESCs. The expression of non-coding RNA (ncRNA) Lin28a and other epigenetic regulatory genes, nucleocytoplasmic trafficking and genes participating in spermatogenesis have also declined faster in the differentiating Mageb16 KD ESCs. We conclude that Mageb16 plays a crucial role for differentiation of ESCs, specifically to the mesodermal lineages. Regulative epigenetic networks and nucleocytoplasmic modifications induced by Mageb16 may play a role for the critical role of Mageb16 for the ESCs differentiation.
Depletion of Mageb16 induces differentiation of pluripotent stem cells predominantly into mesodermal derivatives.
Sex, Specimen part
View SamplesFoxp3+ regulatory T (Treg) cells prevent inflammatory disease but the mechanistic basis of suppression is not understood completely . Gene silencing by RNA interference can act in a cell-autonomous and non-cell-autonomous manner, providing mechanisms of inter-cellular regulation. Here, we demonstrate that non-cell-autonomous gene silencing, mediated by miRNA-containing exosomes, is a mechanism employed by Treg cells to suppress T cell-mediated disease. Treg cells transferred microRNAs (miRNA) to various immune cells, including T helper 1 (Th1) cells, suppressing Th1 cell proliferation and cytokine secretion. Use of Dicer-deficient or Rab27a and Rab27b double-deficient Treg cells to disrupt miRNA-biogenesis or the exosomal pathway, respectively, established a requirement for miRNAs and exosomes for Treg cell-mediated suppression. Transcriptional analysis and miRNA inhibitor studies showed that exosome-mediated transfer of Let-7d from Treg cell to Th1 cells contributed to suppression and prevention of systemic disease. These studies reveal a mechanism of Treg cell-mediated suppression mediated by miRNA-containing exosomes.
MicroRNA-containing T-regulatory-cell-derived exosomes suppress pathogenic T helper 1 cells.
Specimen part
View SamplesThis study revealed pathogenic role of pre-BCR-independent SYK activation in high-risk B-ALL.
Therapeutic potential of spleen tyrosine kinase inhibition for treating high-risk precursor B cell acute lymphoblastic leukemia.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
STAT6 transcription factor is a facilitator of the nuclear receptor PPARγ-regulated gene expression in macrophages and dendritic cells.
Specimen part, Treatment, Subject, Time
View SamplesC57Bl/6 wild-type and STAT6 KO mice were used to study PPARg and IL-4 signaling. Bone marrow of 3 mice per group was isolated and differentiated to macrophages with M-CSF (20 ng/ml). 20 ng/ml IL-4 was used to induce alternative macrophage activation and 1 uM Rosiglitazone (RSG) was used to activate PPARg. From each mouse 4 samples were generated: 1. M-CSF, 2. M-CSF+RSG, 3. IL-4 and 4. IL-4+RSG. All compounds were added throughout the whole differentiation process, and frech media was added every other day. Control cells were treated with vehicle (DMSO:ethanol). After 10 days, RNA was isolated and gene expression profiles were analyzed using Mouse Genome 430 2.0 microarrays from Affymetrix.
STAT6 transcription factor is a facilitator of the nuclear receptor PPARγ-regulated gene expression in macrophages and dendritic cells.
Specimen part, Treatment, Time
View SamplesThe insulin-like growth factor (IGF) axis is an important signaling pathway in the growth and survival of many cell types and has been implicated in multiple aspects of cancer progression from tumorigenesis to metastasis. The multiple roles of IGF signaling in cancer suggest that selective inhibition of the pathway might yield clinically effective therapeutics. Here we describe A-928605, a novel small molecule inhibitor of the receptor tyrosine kinase responsible for IGF signal transduction. This small molecule is able to abrogate activation of the pathway as shown by effects on the target and downstream effectors and is shown to be effective at inhibiting the proliferation of an oncogene addicted tumor model cell line (CD8-IGF1R 3T3) both in vitro and in vivo.
Reversal of oncogene transformation and suppression of tumor growth by the novel IGF1R kinase inhibitor A-928605.
No sample metadata fields
View SamplesProgressive tissue fibrosis is a major cause of morbidity, and idiopathic pulmonary fibrosis (IPF) is a terminal illness characterized by unremitting matrix deposition in the lung with very limited choice of therapies. The imcomplete understanding of the mechanisms of progressive fibrosis curbs the progress in therapeutics development. Of which, the origin of fibrotic fibroblasts has been poorly defined during the pathogenesis of tissue fibrosis. Here, we fate-mapped a early embryonic transcription factor T-box gene 4 (Tbx4)-derived mesenchymal progenitors in injured adult lung and found that Tbx4+ lineage cells are the major source of myofibroblasts. The ablation of Tbx4+ cells or disruption of Tbx4 signaling attenuated lung fibrosis in bleomycin injury model in mice in vivo. Furthermore, Tbx4+ fibroblasts are more invasive and the regulation of fibroblast invasiveness by Tbx4 is through mediating hyaluronan synthase 2 (HAS2). This study identified a major mesenchymal transcription factor driving the development of fibrotic fibroblasts during lung fibrosis. Understanding the origin, signaling, and functions of these fibroblasts would prove pivotal in the development of therapeutics for patients with progressive fibrotic diseases.
Transcription factor TBX4 regulates myofibroblast accumulation and lung fibrosis.
Specimen part
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