We sought to identify genes regulated by the transcription factor Th-POK (Zbtb7b) in liver Va14i NKT cells, by RNA microarray analysis of global gene expression in Va14i NKT cells from mice homozygous for the Th-POK-inactivating hd point mutation as compared with the same cell population isolated from heterozygous or wild-type age-matched mice.
The transcription factor Th-POK negatively regulates Th17 differentiation in Vα14i NKT cells.
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View SamplesHomeobox genes of the Hox class are required for proper patterning of skeletal elements and play a role in cartilage differentiation. In transgenic mice with overexpression of Hoxd4 during cartilage development, we observed severe defects, namely physical instability of cartilage, accumulation of immature chondrocytes, and decreased maturation to hypertrophy. To define the molecular basis underlying these defects, we performed gene expression profiling using the Affymetrix microarray platform.
Microarray Analysis of Defective Cartilage in Hoxc8- and Hoxd4-Transgenic Mice.
Specimen part
View SamplesHomeobox genes of the Hox class are required for proper patterning of skeletal elements and play a role in cartilage differentiation. In transgenic mice with overexpression of Hoxc8 during cartilage development, we observed severe defects, namely physical instability of cartilage, accumulation of immature chondrocytes, and decreased maturation to hypertrophy. To define the molecular basis underlying these defects, we performed gene expression profiling using the Affymetrix microarray platform.
Microarray Analysis of Defective Cartilage in Hoxc8- and Hoxd4-Transgenic Mice.
Specimen part
View SamplesThe TLX1 and TLX3 transcription factor oncogenes play an important role in the pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL)1,2. Here we used reverse engineering of global transcriptional networks to decipher the oncogenic regulatory circuit controlled by TLX1 and TLX3. This Systems Biology analysis defined TLX1 and TLX3 as master regulators of an oncogenic transcriptional circuit governing T-ALL. Notably, network structure analysis of this hierarchical network identified RUNX1 as an important mediator of TLX1 and TLX3 induced T-ALL, and predicted a tumor suppressor role for RUNX1 in T-cell transformation. Consistent with these results, we identified recurrent somatic loss of function mutations in RUNX1 in human T-ALL. Overall, these results place TLX1 and TLX3 atop of an oncogenic transcriptional network controlling leukemia development, demonstrate power of network analysis to identify key elements in the regulatory circuits governing human cancer and identify RUNX1 as a tumor suppressor gene in T-ALL.
Disregulated expression of the transcription factor ThPOK during T-cell development leads to high incidence of T-cell lymphomas.
Specimen part, Cell line
View SamplesTransgenic expression of key transcritpion factors inducing T-cell leukemias in mice.
Disregulated expression of the transcription factor ThPOK during T-cell development leads to high incidence of T-cell lymphomas.
Specimen part
View SamplesThe experiment was designed in order to knock down the expression of TLX3 gene in T-ALL cell line
Disregulated expression of the transcription factor ThPOK during T-cell development leads to high incidence of T-cell lymphomas.
Cell line
View SamplesThe experiment was designed in order to knock down the expression of TLX1 gene in T-ALL cell line
Disregulated expression of the transcription factor ThPOK during T-cell development leads to high incidence of T-cell lymphomas.
Cell line
View SamplesDiabetic embryopathy can affect any developing organ system, although cardiovascular malformations, neural tube defects and caudal dysgenesis syndrome are the most prominent congenital malformations. We hypothesize that the metabolic imbalance occurring in diabetic pregnancy de-regulates tissue specific gene expression programs in the developing embryo. In order to identify genes whose expression is affected by maternal diabetes, we analyzed gene expression profiles of diabetes-exposed mouse embryos by using Affymetrix microarrays. We identified 129 genes with altered expression levels; 21 genes had increased and 108 genes had decreased expression levels in diabetes-exposed embryos relative to controls. A substantial fraction of these genes (35) are essential for normal embryonic development as shown by functional studies in mouse models. The largest fraction of diabetes-affected genes was in transcription factor and DNA-binding/chromatin remodeling functional categories (19%), which directly affect transcription. These findings suggest that transcriptional regulation in the developing embryos is perturbed by maternal diabetes and that transcriptional regulation plays a major role in the responses of embryos to intrauterine exposure to diabetic conditions. Interestingly, we found the expression of hypoxia-inducible factor 1 (Hif1) deregulated in the embryos exposed to the conditions of maternal diabetes. Since hypoxic stress is associated with the complications of diabetic pregnancy, we performed a post-hoc analysis of our microarray data with a specific focus on known HIF1 target genes. Of 39 genes detected in our microarrays, the expression changes of 22 genes (20 were increased and two genes were decreased in diabetes-exposed embryos) were statistically significant. These results indicate that HIF1-regulated pathways are affected in diabetes-exposed embryos. These results strongly suggest that de-regulation of hypoxia/HIF1 activated pathways could be the one of the key molecular events associated with the exposure to the teratogenic intrauterine environment of a diabetic mother.
Maternal diabetes alters transcriptional programs in the developing embryo.
Specimen part
View SamplesExposure to maternal diabetes during pregnancy alters transcriptional profiles in the developing embryo. The enrichment, within the set of de-regulated genes, of those encoding transcriptional regulatory molecules provides support for the hypothesis that maternal diabetes affects specific developmental programs.
Maternal diabetes alters transcriptional programs in the developing embryo.
Specimen part, Disease, Disease stage
View SamplesTransposable elements (TEs) make up a large proportion of eukaryotic genomes. As their mobilization creates genetic variation that threatens genome integrity, TEs are epigenetically silenced through several pathways and this may spread to neighboring sequences. JUMONJI (JMJ) proteins can function as anti-silencing factors and prevent silencing of genes next to TEs. Whether TE silencing is counterbalanced by the activity of anti-silencing factors is still unclear. Here, we characterize JMJ24 as a regulator of TE silencing. We show that loss of JMJ24 results in increased silencing of the DNA transposon AtMu1c, while overexpression of JMJ24 reduces silencing. JMJ24 has a JumonjiC (JmjC) domain and two RING domains. JMJ24 auto-ubiquitinates in vitro, demonstrating E3 ligase activity of the RING domain(s). JMJ24-JmjC binds the N-terminal tail of histone H3 and full-length JMJ24 binds histone H3 in vivo. JMJ24 activity is anti-correlated with histone H3 lysine 9 dimethylation (H3K9me2) levels at AtMu1c. Double mutant analyses with epigenetic silencing mutants suggest that JMJ24 antagonizes histone H3K9me2, and requires H3K9 methyltransferases for its activity on AtMu1c. Genome-wide transcriptome analysis indicates that JMJ24 affects silencing at additional TEs. Our results suggest that the JmjC domain of JMJ24 has lost demethylase activity but has been retained as a binding domain for histone H3. This is in line with phylogenetic analyses indicating that JMJ24 [with the mutated JmjC domain] is widely conserved in angiosperms. Taken together, this study assigns a role in TE silencing to a conserved JmjC-domain protein with E3 ligase activity, but no demethylase activity.
A JUMONJI Protein with E3 Ligase and Histone H3 Binding Activities Affects Transposon Silencing in Arabidopsis.
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