Small nucleolar RNAs (snoRNAs) and small Cajal body-specific RNAs (scaRNAs) are non-coding RNAs involved in the maturation of other RNA molecules and generally located in the introns of host genes. It is now emerging that altered sno/scaRNAs expression may play a pathological role in cancer. This study elucidates the patterns of sno/scaRNAs expression in multiple myeloma (MM), by profiling puri?ed malignant plasma cells from 55 MMs, 8 secondary plasma cell leukemias (sPCL) and 4 normal controls. Overall, a global sno/scaRNAs down-regulation was found in MMs and at more extent in sPCLs compared to normal plasma cells. Whereas SCARNA22 resulted the only sno/scaRNA characterizing the TC4 MM, TC2 group displayed a distinct sno/scaRNA signature overexpressing members of SNORD115 and SNORD116 families located in a region finely regulated by imprinting mechanism at 15q11. However, the imprinting center resulted overall hypomethylated in MMs independently of the SNORD115 and SNORD116 expression levels. Finally, integrative analyses with available gene expression and genome-wide data revealed the occurrence of significant sno/scaRNAs/host genes co-expression and the putative influence of allelic imbalances on specific snoRNAs expression. Our data extend the current view of sno/scaRNAs deregulation in cancer and add novel information into the bio-molecular complexity of plasma cell dyscrasias.
The expression pattern of small nucleolar and small Cajal body-specific RNAs characterizes distinct molecular subtypes of multiple myeloma.
Specimen part, Disease, Disease stage
View SamplesThe homeobox containing gene Arx is expressed during ventral telencephalon development and it is required for correct GABAergic interneuron tangential migration from the ganglionic eminences to the olfactory bulbs, cerebral cortex and striatum. Its human ortholog is associated with a variety of neurological clinical manifestations whose syntoms are compatible with a loss of cortical interneurons and altered basal ganglia related-activities in humans. Herein, we reported the identification by global expression profiling of a group of genes whose expression is consistently altered in Arx mutant ganglionic eminences. Following analysis revealed the striking ectopic expression in the ganglionic eminences of a number of genes normally not, or only marginally, expressed in the ventral telencephalon. Among them, we functionally analyzed Ebf3, whose ectopic expression in ventral telencephalon is preventingneuronal tangential migration. Further, we showed that Arx is sufficient to repress Ebf3 endogenous expression and that its silencing in Arx mutant tissue might marginally rescue tangential cell movements. Together, these data provide an initial analysis of the molecular pathways regulated by Arx and how their networking might regulate those specific cellular processes during telencephalon development strongly altered by loss of Arx.
Arx acts as a regional key selector gene in the ventral telencephalon mainly through its transcriptional repression activity.
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View SamplesMicroglia colonize the brain parenchyma at early stages of development and accumulate in specific regions where they actively participate in cell death, angiogenesis, neurogenesis and synapse elimination. A recurring feature of embryonic microglial distribution is their association with developing axon tracts which, together with in vitro data, supports the idea of a physiological role for microglia in neurite development. Yet the demonstration of this role of microglia is still lacking. Here, we have studied the consequences of microglial dysfunction on the formation of the corpus callosum, the largest connective structure in the mammalian brain, which shows consistent microglial accumulation during development. We studied two models of microglial dysfunction: the loss-of-function of DAP12, a key microglial-specific signaling molecule, and a model of maternal inflammation by peritoneal injection of LPS at E15.5. We performed transcriptional profiling of maternally inflamed and Dap12-mutant microglia at E17.5. We found that both treatments principally down-regulated genes involved in nervous system development and function, particularly in neurite formation. We then analyzed the functional consequences of these microglial dysfunctions on the formation of the corpus callosum. We also took advantage of the Pu.1-/- mouse line, which is devoid of microglia. We now show that all three models of altered microglial activity resulted in the same defasciculation phenotype. Our study demonstrates that microglia are actively involved in the fasciculation of corpus callosum axons.
Microglia shape corpus callosum axon tract fasciculation: functional impact of prenatal inflammation.
Sex, Specimen part, Treatment
View SamplesWe used microarrays to assess gene expression differences in the hippocampus between FoxO6 mutant and wild-type siblings before (basal) or after novel object learning.
FoxO6 regulates memory consolidation and synaptic function.
Sex, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
The Tbr2 Molecular Network Controls Cortical Neuronal Differentiation Through Complementary Genetic and Epigenetic Pathways.
Specimen part
View SamplesThe abscence of TBR2 gene in human leads to microcephaly. This condition is mimicked by the specific ablation of the murine gene in developing cerebral cortex. Herein we compared gene expression in control and Tbr2 cKO in E14.5 cerebral cortices. This approach represents a useful tool to identify the molecular mechanisms at the basis of the phenotype.
The Tbr2 Molecular Network Controls Cortical Neuronal Differentiation Through Complementary Genetic and Epigenetic Pathways.
Specimen part
View SamplesPMID: 15539473. We compared the gene expression in roots between WT and fit mutant under +Fe and -Fe conditions using ATH1 microarray analysis to explore which genes are affected by the loss of FIT function.
The essential basic helix-loop-helix protein FIT1 is required for the iron deficiency response.
Specimen part, Treatment
View SamplesAging is associated with functional decline of hematopoietic stem cells (HSC) as well as an increased risk of myeloid malignancies. We performed an integrative characterization of epigenomic and transcriptomic changes, including single-cell RNA-seq, during normal human aging. Lineage-CD34+CD38- cells (HSC-enriched, HSCe) undergo age-associated epigenetic reprogramming consisting of redistribution of DNA methylation and reductions in H3K27ac, H3K4me1 and H3K4me3. This reprogramming of aged HSCe globally targets developmental and cancer pathways which are comparably altered in AML of all ages; encompassing loss of 4,656 active enhancers, 3,091 bivalent promoters, and deregulation of several epigenetic modifiers and key hematopoietic transcription factors, such as KLF6, BCL6 and RUNX3. Notably, in vitro downregulation of KLF6 results in impaired differentiation, increased colony forming potential and changes in expression that recapitulate aging and leukemia signatures. Thus, age-associated epigenetic reprogramming may form a predisposing condition for the development of age-related AML. Overall design: We profiled the human HSCe (Lineage-, CD34+, CD38-) transcriptome with aging at the single cell level. Single-cell RNAseq was performed on FACS isolated human bone marrow derived HSCe from 5 young (24-37 yo) and 4 aged donor (64-71 yo). Donors had no known hematological malignancy.
Aging Human Hematopoietic Stem Cells Manifest Profound Epigenetic Reprogramming of Enhancers That May Predispose to Leukemia.
Specimen part, Subject
View SamplesAging is associated with functional decline of hematopoietic stem cells (HSC) as well as an increased risk of myeloid malignancies. We performed an integrative characterization of epigenomic and transcriptomic changes, including single-cell RNA-seq, during normal human aging. Lineage-CD34+CD38- cells (HSC-enriched, HSCe) undergo age-associated epigenetic reprogramming consisting of redistribution of DNA methylation and reductions in H3K27ac, H3K4me1 and H3K4me3. This reprogramming of aged HSCe globally targets developmental and cancer pathways which are comparably altered in AML of all ages; encompassing loss of 4,656 active enhancers, 3,091 bivalent promoters, and deregulation of several epigenetic modifiers and key hematopoietic transcription factors, such as KLF6, BCL6 and RUNX3. Notably, in vitro downregulation of KLF6 results in impaired differentiation, increased colony forming potential and changes in expression that recapitulate aging and leukemia signatures. Thus, age-associated epigenetic reprogramming may form a predisposing condition for the development of age-related AML. Overall design: CRISPR-Cas9 mediated knockout of KLF6 was performed in human peripheral blood CD34+ cells (n=4 replicates). RNA-seq was utilized to determine the effect of KLF6 knockout compared to a non-targeting control control.
Aging Human Hematopoietic Stem Cells Manifest Profound Epigenetic Reprogramming of Enhancers That May Predispose to Leukemia.
Sex, Age, Specimen part, Treatment, Subject
View SamplesDirect cell reprogramming has enabled the direct conversion of skin fibroblasts into functional neurons and oligodendrocytes using a minimal set of cell lineage-specific transcription factors. This approach has substantial advantages since it is rapid and simple, generating the cell type of interest in a single step. However, it remains unknown whether this technology can be applied for directly reprogramming skin cells into astrocytes, the third neural lineage. Astrocytes play crucial roles in neuronal homeostasis and their dysfunctions contribute to the origin and progression of multiple human diseases. Herein, we carried out a screening using several transcription factors involved in defining the astroglial cell fate and identified NFIA, NFIB and SOX9 to be sufficient to convert with high efficiency embryonic and post-natal mouse fibroblasts into astrocytes (iAstrocytes). We proved both by gene expression profiling and functional tests that iAstrocytes are comparable to native brain astrocytes. This protocol can be then employed to generate functional iAstrocytes for a wide range of experimental applications.
Direct conversion of fibroblasts into functional astrocytes by defined transcription factors.
Specimen part
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