Laf4/Aff3 is required for normal neuronal migration
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ABSTRACT: The aim of this study was to investigate the function of Laf4 in the brain by focusing on its role in the developing cortex. By manipulating expression levels in organotypic slices, we demonstrate that Laf4 is required for normal cellular migration in the cortex and have subsequently identified Mdga2, an important structural protein in neurodevelopment, as a direct target of Laf4 transcriptional activity.
Project description:Evolution of the mammalian brain encompassed a remarkable increase in size of cerebral cortex, including tangential and radial expansion, but the mechanisms underlying these key parameters are still largely unknown. Here, we identified the novel DNA associated protein TRNP1 as a regulator of cerebral cortical expansion in both these dimensions. Gain and loss of function experiments in the mouse cerebral cortex in vivo demonstrate that high Trnp1 levels promote neural stem cell self-renewal and tangential expansion, while lower levels promote radial expansion resulting in a potent increase in the generation of intermediate progenitors and outer radial glial cells resulting in folding of the otherwise smooth murine cerebral cortex. Remarkably, TRNP1 expression levels exhibit regional differences also in the cerebral cortex of human fetuses anticipating radial or tangential expansion respectively. Thus, the dynamic regulation of TRNP1 is critical to regulate tangential and radial expansion of the cerebral cortex in mammals. We performed gene expression microarray analysis on embryonic mouse cerebral cortex derived from Trnp1 knockdown and control animals.
Project description:LMO2 overexpressing transgenic mouse models suggest an accumulation of immature T-cell progenitors in the thymus as main pre-leukemic event. The effects of LMO2 overexpression on human T-cell development in vivo, however, are unknown. Here we report studies of a humanized mouse model transplanted with LMO2 transduced human hematopoietic stem and progenitor cells. The effects of LMO2 overexpression were confined to the T-cell lineage although initially multipotent cells were transduced. Three effects of LMO2 on human T-cell development were observed: 1) a block at the DN/ISP stage, 2) an accumulation of CD4+CD8+ double positive CD3- cells and 3) an altered CD8/CD4 ratio with enhanced peripheral T lymphocytes Single stranded cDNA was synthesized from 1000 pg total RNA using the Ovation Pico WTA System V2 Module (NuGEN Technologies Inc, Leek, The Netherlands) in combination with the Encore Biotin Module (NuGEN Technologies Inc) according to the instructions of the manufacturer. Biotin labeling and fragmentation was performed and fragmented cDNA was hybridized onto Affymetrix Gene Atlas human U219 arrays.
Project description:We evaluated gene expression changes in murine leukemia caused by retroviral overexpression of MLL-AF9. We compared wild-type (WT) leukemia cells with mutant leukemia cells after cre-mediated inactivation of homozygous conditional alleles for Ezh2 or Eed, both of which are components of the Polycomb Repressive Complex2. For WT cells, 3 biological replicates were hybridized. For Ezh2-null cells, 4 biological replicates were hybridized. For Eed-cells, 3 biological replicates were hybridized.
Project description:We evaluated gene expression changes in secondary recipient murine leukemia caused by retroviral overexpression of MLL-AF9. We compared wild-type (WT) leukemia cells with mutant leukemia cells after cre-mediated inactivation of a homozygous conditional allele for Ezh2, a component of the Polycomb Repressive Complex2. For WT cells, 4 biological replicates were hybridized. For Ezh2-null cells, 5 biological replicates were hybridized.
Project description:This SuperSeries is composed of the following subset Series: GSE34959: Expression profiling of primary wild type (WT), Ezh2-null and Eed-null murine MLL-AF9 AML GSE34961: Expression profiling of secondary wild type (WT) and Ezh2-null murine MLL-AF9 AML GSE34962: Epigenetic profiling of WT and Ezh2-null MLL-AF9 murine leukemic cells Refer to individual Series
Project description:The goal was to study the role of Hlx in hematopoiesis. Sorted Lin-Kit+Sca-1+ cells from wild-type FVB/nJ bone marrow were infected with control (pCAD-IRES-GFP) or Hlx lentivirus (pCAD-IRES-GFP-Hlx) and cultured for 2 days in Iscove’s modified Dulbecco’s medium (IMDM) containing FBS, mIL-3, mIL-6 and mSCF with lentiviral supernatants in the presence of 8ug/ml polybrene. Subsequently, GFP+ cells were sorted by FACS and RNA was prepared. Three replicates of each, control vector transduced and HLX-transduced cells were used.
Project description:The long term objective is to create an encyclopedia of the expression levels of all genes in multiple components of the developing kidney. The central thesis is straightforward. The combination of fluorescent activated cell sorting (FACS) plus microarray analysis offers a powerful, efficient and effective method for the creation of a global gene expression atlas of the developing kidney. Microarrays with essentially complete genome coverage can be used to quantitate expression levels of every gene in FACS isolated components of the developing kidney. The ensuing rapid read-out provides an expression atlas that is more sensitive, more economical and more complete than would be possible by in situ hybridizations alone. YFP & GFP transgenic lines have been used to isolate several cell types including the metanephric mesenchyme, Juxtaglomerular Complex cells or renal cortex from the kidneys of either E11.5 embryos or adult mice. The various cell types were isolated from the kidney using microdissection and single-cell isolation techniques. RNA was isolated from cells and the gene expression profiles were determined by microarrays.
Project description:Translocations involving the MLL genes are frequently found in Acute Myeloid Leukemia (AML) and are associated with poor prognosis. The MLL fusion proteins act as aberrant transcription factor activating a transcriptional program that transforms the cells, potentially through collaboration with other transcription factors. To investigate this we searched gene expression profiles from patients with MLL-rearranged AML compared with normal hematopoietic progenitor cells for transcriptional regulators and found targets of C/EBPα to be up-regulated in the AML samples, suggesting that C/EBPα might collaborate with MLL fusion proteins in the initial transformation process. We could show that transformation by MLL fusion proteins is dependent on C/EBPα activity both in early progenitors as well as in GMPs. In contrast, C/EBPα was found to be indispensable in an already established leukemia. These results suggest that C/EBPα play an important role in the early transforming event of leukemogenesis. We used microarray to study the early transcriptional changes induced by MLL-ENL expression and we identified a combined C/EBPα / MLL-ENL transcriptional signature. 3 Cebpaflox/flox;Mx1Cre and 3 Cebpaflox/flox;Mx1Cre- mice were sacrificed 14 days after pIpC injection and bone marrow cells were harvested, enriched for cKit-expression and transduced with a pMIG retroviral vector expressing the MLL-ENL fusion protein and GFP. 72 h post first transduction, GFP-positive or negative PreGM cells were sorted.
Project description:We employ RNA-seq of FACS sorted cell populations to identify genes that are enriched in cranial neural crest in relationship to the trunk. Transcriptional profiling of delaminating cranial and trunk neural crest subpopulations.