GDAP1 is a mitochondrial fission factor and mutations in GDAP1 cause Charcot-Marie-Tooth disease. Gdap1 knockout mice, mimicking genetic alterations of patients suffering from severe CMT forms, develop an age-related, hypomyelinating peripheral neuropathy.
The Gdap1 knockout mouse mechanistically links redox control to Charcot-Marie-Tooth disease.
Specimen part
View SamplesPrimordial genomic challenge compromises embryonic development and survival, and surveillance of deployed transcriptional programs may provide an early opportunity to forecast phenotype abnormalities. Here, comparisons between wild-type and calreticulin-ablated embryonic stem cells revealed transcriptome shifts precipitated by calreticulin loss. Bioinformatic analysis identified down and up-regulation in 1187 and 418 genes, respectively. Cardiovascular development precedes other organogenic programs, and examination of cardiogenic genes revealed a map of calreticulin-calibrated expression profiles that encompass the developmental regulators, Ccnd1, Ccnd2 and Notch1. Interrogation of primary function in the resolved network forecasted abnormalities during myocardial development. Whole embryo magnetic resonance imaging, verified by pathoanatomical analysis, diagnosed prominent ventricular septal defect. Correlation clustering and network resolution of probesets associated with protein folding/chaperoning and calcium handling demonstrated 14 and 19 genes, respectively, modulated by calreticulin deficiency. Calreticulin deletion provoked ontological re-prioritization of gene expression, molecular transport and protein trafficking that translated into multiple subcellular functional outcomes. Individual stem cell-derived cardiomyocytes lacking calreticulin demonstrated a disorganized contractile apparatus with mitochondrial paucity and architectural aberrations. Thus, bioinformatic deconvolution of primordial embryonic stem cell transcriptomes enables predictive phenotyping of defective developmental networks that coalesce from complex systems biology hierarchies.
Decoded calreticulin-deficient embryonic stem cell transcriptome resolves latent cardiophenotype.
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View SamplesHopx appears to be needed for persistence of Th1 effector memory cells. IFN-gamma-producing Th cells are significantly reduced in Hopx-deficient mice compared to Hopx-expressing littermates and Hopx-deficient Th1 cells show a defective persistence upon adoptive transfer. Moreover, Hopx protects Th1 cells from Fas-mediated cell death in vitro. To further dissect the role of Hopx and to identify target genes of Hopx, we have performed transcriptome analysis to compare gene expression in Hopx-deficient versus Hopx-competent Th1 cells. In agreement with the role of Hopx in supporting survival of Th1 effector memory cells, anti-apoptotic cells were up-regulated and pro-apoptotic genes were down-regulated in Hopx-competent compared to Hopx-deficient Th1 cells.
Persistence of effector memory Th1 cells is regulated by Hopx.
Sex, Specimen part
View SamplesPlasmacytoid dendritic cells (pDC) efficiently produce large amounts of type I interferon in response to TLR7 and TLR9 ligands, whereas conventional DCs (cDC) predominantly secrete high levels of the cytokines IL-10 and IL-12. The molecular basis underlying this distinct phenotype is not well understood. Here, we identified the MAPK phosphatase Dusp9/MKP-4 by transcriptome analysis as selectively expressed in pDC, but not cDC. We confirmed the constitutive expression of Dusp9 at the protein level in pDC generated in vitro by culture with Flt3L and ex vivo in sorted splenic pDC. Dusp9 expression was low in B220- bone marrow precursors and was up-regulated during pDC differentiation, concomitant with established pDC markers. Higher expression of Dusp9 in pDC correlated with impaired phosphorylation of the MAPK ERK1/2 upon TLR9 stimulation. Notably, Dusp9 was not expressed at detectable levels in human pDC, although these displayed similarly impaired activation of ERK1/2 MAPK compared to cDC. Enforced retroviral expression of Dusp9 in mouse GM-CSF-induced cDC increased the expression of TLR7/9-induced IL-12p40 and IFNwhereas IL-10 levels were diminished. Taken together, our results suggest that the species-specific, selective expression of Dusp9 in murine pDC contributes to the differential cytokine/interferon output of pDC and cDC.
Selective Expression of the MAPK Phosphatase Dusp9/MKP-4 in Mouse Plasmacytoid Dendritic Cells and Regulation of IFN-β Production.
No sample metadata fields
View SamplesThe transcriptional repressor Zbtb20 is essential for specification of hippocampal CA1 pyramidal neurons. Moreover, ectopic expression of Zbtb20 is sufficient to transform subicular and retrosplenial areas of D6/Zbtb20S mice to CA1. We used microarrays to identify genes that are repressed by Zbtb20 in developing CA1 pyramidal neurons in the CA1-transformed cortex of D6/Zbtb20S mice.
Zbtb20 defines a hippocampal neuronal identity through direct repression of genes that control projection neuron development in the isocortex.
Specimen part
View SamplesLactobacilli are probiotics that, among other health promoting effects, have been ascribed immunostimulating and virus preventive properties. Certain lactobacilli species have been shown to possess strong IL-12 inducing properties. As IL-12 production depends on the up-regulation of type I interferons, we hypothesized that the strong IL-12 inducing capacity of L. acidophilus NCFM in murine bone marrow derived DC is caused by an up-regulation of IFN-, which subsequently stimulates the induction of IL-12 and the dsRNA binding toll like receptor (TLR)-3. The expression of the genes encoding IFN-, IL-12, IL-10 and TLR-3 in DC upon stimulation with L. acidophilus NCFM was measured. L. acidophilus NCFM induced a much stronger expression of ifn-, il-12 and il-10 compared to the synthetic dsRNA ligand Poly I:C, whereas the levels of expressed tlr-3 were similar. By the use of whole genome microarray gene expression, we investigated whether other genes related to the viral defence were up-regulated in DC upon stimulation with L. acidophilus NCFM and found that various virus defence related genes, both early and late, were among the strongest up-regulated genes. The IFN- stimulating capability was also detected in another L. acidophilus strain, but was not a property of other probiotic bacteria tested (B. bifidum and E. coli nissle).The IFN- inducing capacity was markedly reduced in TLR-2 -/- DCs, dependent on endocytosis and the major cause of the induction of il-12 and tlr-3 in L. acidophilus NCFM stimulated cells. Collectively, our results reveal that certain lactobacilli trigger the expression of viral defence genes in DC in a TLR-2 manner through induction of IFN- .
Lactobacillus acidophilus induces virus immune defence genes in murine dendritic cells by a Toll-like receptor-2-dependent mechanism.
Treatment, Time
View SamplesGene expression profiles of Immortalized KDM5A-/- MEFs with re-introduction of wild-type KDM5A or KDM5A-H483A mutant.
The KDM5 family is required for activation of pro-proliferative cell cycle genes during adipocyte differentiation.
Specimen part
View SamplesXBP1 is the transcriptino factor that is activated by the ER stress. XBP1 is known to induce the ER dexpansion and increase the expression of the ER chaperone genes to prtect the cell from the ER stress. We generated a mouse strain that lacked XBP1 specifically in the mouse intestine by breeding the XBP1flox mice with Villin-cre mice. Here we examined genes that are differentially expressed between WT and XBP1 KO mouse intestine to identify genes that are downstream of XBP1.
XBP1 links ER stress to intestinal inflammation and confers genetic risk for human inflammatory bowel disease.
No sample metadata fields
View SamplesFluorescent-labeled zebrafish RAS-induced embryonal rhabdomyosarcoma (ERMS) were created to facilitate in vivo imaging of tumor-propagating cells, regional tumor heterogeneity, and dynamic cell movements in diverse cellular compartments. Using this strategy, we have identified a molecularly distinct ERMS cell subpopulation that expresses high levels of myf5 and is enriched for ERMS-propagating potential when compared with other tumor-derived cells. Embryonal rhabdomyosarcoma (ERMS) is an aggressive pediatric sarcoma of muscle. Here, we show that tumor-propagating potential is confined to myf5+ERMS cells and can be visualized in live, fluorescent transgenic zebrafish. During early tumor growth, myf5+ERMS cells reside within an expanded satellite cell compartment, but by late stage ERMS, myf5+cells are dynamically reorganized into distinct regions separated from differentiated tumor cells. Human ERMS also contain distinct areas of differentiated and undifferentiated cells. Time-lapse imaging revealed that myf5+ERMS cells populate newly formed tumor only after seeding by highly migratory myogenin+ ERMS cells. This finding helps explain the clinical observation that Myogenin positivity correlates with poor clinical outcome in human ERMS and suggests that differentiated tumor cells play critical roles in metastasis. One-cell stage myf5-GFP/mylz2-mCherry fluorescent transgenic zebrafish were injected with rag2-kRAS12D. A subset of animals developed ERMS. Tumor cells were transplanted into syngeneic recipient animals that lacked fluorescent reporter expression. ERMS cell subfractions were isolated from transplant animals and purified cell populations obtained following two rounds of FACS. Sorted cells were 1) analyzed by microarray/RT-PCR and 2) transplanted at limiting dilution into syngeneic animals. These experiments confirm that zebrafish ERMS contain molecularly distinct cell subfractions that express high levels of myf5-GFP and exhibit difference in gene expression when compared to other ERMS cell subtypes. All four fluorescent-labeled cell populations were analyzed (n=2 tumors total).
In vivo imaging of tumor-propagating cells, regional tumor heterogeneity, and dynamic cell movements in embryonal rhabdomyosarcoma.
Specimen part, Disease, Disease stage, Subject
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