Global developmental gene expression and pathway analysis of normal brain development and mouse models of human neuronal migration defects
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE35366 | GEO | 2012/01/26
SECONDARY ACCESSION(S): PRJNA152639
REPOSITORIES: GEO
Similar Datasets
Project description:Proper cortical development relies on the balance of neuronal migration and proliferation. We investigated the gene expression differences of mouse knock-outs for Lissencephaly in humans. Our analysis suggests that gene expression and pathway analysis in mouse models of a similar disorder or within a common pathway can be used to define novel candidates for related human diseases. We investigated the developing brain of four mutants and wild-type mice using expression microarrays, bioinformatic analyses, and in vivo/in vitro experiments to address whether mutations in different members of the LIS1 neuronal migration complex lead to similar and/or distinct global gene expression alterations.
2012-01-26 | E-GEOD-35366 | biostudies-arrayexpress
Project description:Mutation or deletion of LIS1 (Lissencephaly-1) underlies classical lissencephaly, a migration disorder resulting in brain malformation, epilepsy and mental retardation. Orthologues for LIS1 genes (lis1a and lis1b) are ubiquitously expressed in developing zebrafish larvae, but the functional consequences of Lis1 knockdown are unknown. Here we used lis1-specific morpholino oligonucleotides (MOs, targeting protein translation or mRNA splicing, respectively) to transiently knockdown Lis1 expression in zebrafish. Injection of lis1 MOs resulted in morphological changes including microcephaly. At four days post-fertilization, lis1 morphants exhibited spontaneous convulsive behavior and abnormal large-amplitude electrographic discharge resembling that seen in acute and genetic zebrafish models of epilepsy. Abnormal brain development and neuronal migration defects were observed when lis1 MO injections were made into fluorescent reporter lines demarcating interneuron distribution (Dlx5a/6a:GFP) and brain structure (GBT0133:mRFP). Microarray analysis for ~44,000 Danio rerio transcripts identified 215 up-regulated and 160 down-regulated genes. Quantitative PCR and whole-mount in situ hybridization were used to validate these results for twenty and seven genes, respectively. These findings in a simple vertebrate model reproducing neuroanatomical and epileptic hallmarks of the human condition represent a novel approach to the study of childhood seizure disorders associated with a single gene mutation 4 WT samples (sample= 10 pooled larvae) and 4 Lis1Morphants slight phenotype (sample= 10 pooled larvae) were collected at 4dpf (days post fertilization). The morphants were selected based on phenotype and seizure behavior. Both groups of fish derived from same pools of eggs
2013-06-15 | E-GEOD-47952 | biostudies-arrayexpress
Project description:Mutation or deletion of LIS1 (Lissencephaly-1) underlies classical lissencephaly, a migration disorder resulting in brain malformation, epilepsy and mental retardation. Orthologues for LIS1 genes (lis1a and lis1b) are ubiquitously expressed in developing zebrafish larvae, but the functional consequences of Lis1 knockdown are unknown. Here we used lis1-specific morpholino oligonucleotides (MOs, targeting protein translation or mRNA splicing, respectively) to transiently knockdown Lis1 expression in zebrafish. Injection of lis1 MOs resulted in morphological changes including microcephaly. At four days post-fertilization, lis1 morphants exhibited spontaneous convulsive behavior and abnormal large-amplitude electrographic discharge resembling that seen in acute and genetic zebrafish models of epilepsy. Abnormal brain development and neuronal migration defects were observed when lis1 MO injections were made into fluorescent reporter lines demarcating interneuron distribution (Dlx5a/6a:GFP) and brain structure (GBT0133:mRFP). Microarray analysis for ~44,000 Danio rerio transcripts identified 215 up-regulated and 160 down-regulated genes. Quantitative PCR and whole-mount in situ hybridization were used to validate these results for twenty and seven genes, respectively. These findings in a simple vertebrate model reproducing neuroanatomical and epileptic hallmarks of the human condition represent a novel approach to the study of childhood seizure disorders associated with a single gene mutation
2013-06-15 | GSE47952 | GEO
Project description:Heterozygous LIS1 mutations are the most common cause of human lissencephaly, a human neuronal migration defect, and DCX mutations are the most common cause of X-linked lissencephaly. LIS1 is part of a protein complex including NDEL1 and 14-3-3? that regulates dynein motor function and microtubule dynamics, while DCX stabilizes microtubules and cooperates with LIS1 during neuronal migration and neurogenesis. Targeted gene mutations of Lis1, Dcx, Ywhae (coding for 14-3-3?), and Ndel1 lead to neuronal migration defects in mouse and provide models of human lissencephaly, as well as aid the study of related neuro-developmental diseases. Here we investigated the developing brain of these four mutants and wild-type mice using expression microarrays, bioinformatic analyses, and in vivo/in vitro experiments to address whether mutations in different members of the LIS1 neuronal migration complex lead to similar and/or distinct global gene expression alterations. Consistent with the overall successful development of the mutant brains, unsupervised clustering and co-expression analysis suggested that cell cycle and synaptogenesis genes are similarly expressed and co-regulated in WT and mutant brains in a time-dependent fashion. By contrast, focused co-expression analysis in the Lis1 and Ndel1 mutants uncovered substantial differences in the correlation among pathways. Differential expression analysis revealed that cell cycle, cell adhesion, and cytoskeleton organization pathways are commonly altered in all mutants, while synaptogenesis, cell morphology, and inflammation/immune response are specifically altered in one or more mutants. We found several commonly dysregulated genes located within pathogenic deletion/duplication regions, which represent novel candidates of human mental retardation and neurocognitive disabilities. Our analysis suggests that gene expression and pathway analysis in mouse models of a similar disorder or within a common pathway can be used to define novel candidates for related human diseases.
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Project description:Fetal alcohol spectrum disorder (FASD) is a frequent cause of mental retardation. However, the molecular mechanisms underlying brain development defects induced by maternal alcohol consumption during pregnancy are unclear. We used normal and Hsf2-deficient mice and cell systems to uncover a pivotal role for heat shock factor 2 (HSF2) in radial neuronal migration defects in the cortex, a hallmark of fetal alcohol exposure. Upon fetal alcohol exposure, HSF2 is essential for the triggering of HSF1 activation, which is accompanied by distinctive post-translational modifications, and HSF2 steers the formation of atypical alcohol-specific HSF1-HSF2 heterocomplexes. This perturbs the in vivo binding of HSF2 to heat shock elements (HSEs) in genes that control neuronal migration in normal conditions, such as p35 or the MAPs (microtubule-associated proteins, such as Dclk1 and Dcx), and alters their expression. In the absence of HSF2, migration defects as well as alterations in gene expression are reduced. Thus, HSF2, as a sensor for alcohol stress in the fetal brain, acts as a mediator of the neuronal migration defects associated with FASD.
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Project description:Down Syndrome (DS) is the most common genetic disorder associated with intellectual disability (ID). Excitatory neurons of DS patients and mouse models show decreased size of dendritic field and reduction of spine density. Whether these defects are caused by cell autonomous alterations or by abnormal multicellular circuitry is still unknown. In this work, we explored this issue by culturing cortical neurons obtained from two mouse models of DS: the widely used Ts65Dn and the less characterized Ts2Cje. We observed that, in the in vitro conditions, axon specification and elongation, as well as dendritogenesis, take place without evident abnormalities, indicating that the initial phases of neuronal differentiation do not suffer from the presence of an imbalanced genetic dosage. Conversely, our analysis highlighted differences between trisomic and euploid neurons in terms of reduction of spine density, in accordance with in vivo data obtained by other groups, proposing the presence of a cell-intrinsic malfunction. This work suggests that the characteristic morphological defects of DS neurons are likely to be caused by the possible combination of cell-intrinsic defects together with cell-extrinsic cues. Additionally, our data support the possibility of using the more sustainable line Ts2Cje as a standard model for the study of DS.
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Project description:Human cerebral cortex development is a highly complex and orchestrated process that is under tight genetic regulation. Rare mutations that alter gene expression or function can disrupt the structure of the cerebral cortex, resulting in a variety of neurological cAonditions1. Lissencephaly (“smooth brain”) spectrum disorders comprise a group of rare, genetically heterogeneous congenital brain malformations commonly associated with epilepsy and intellectual disability2. However, the molecular mechanisms underlying disease pathogenesis remain unknown. Here, we establish hypoactivity of the mammalian target of rapamycin (mTOR) pathway as a clinically relevant molecular mechanism in lissencephaly spectrum disorders. We characterized cerebral organoids from individuals with two genetically distinct lissencephalies harboring a recessive mutation in P53-Induced Death Domain Protein 1 (PIDD1) or a heterozygous chromosome 17p13.3 microdeletion leading to Miller-Dieker Lissencephaly Syndrome (MDLS). We found that PIDD1-mutant and MDLS organoids recapitulate the thickened cortex typical of human lissencephaly and demonstrated dysregulation of protein translation, metabolism, and the mTOR pathway. We found that a brain-selective activator of mTOR complex 1 (mTORC1) prevents, and even reverses, cellular and molecular defects in lissencephaly organoids. Our findings unveil an unexpected converging molecular mechanism contributing to genetically heterogeneous lissencephaly spectrum disorders.
2024-10-04 | PXD056364 | Pride
Project description:Microarray characterization of Lsd1 knock-outs compared to littermate controls Microarrays were employed to identify transcripts that were differentially modulated in the hearts of wild-type and Lsd1-hypomorphic late-stage embryos.
2013-03-29 | GSE45583 | GEO
Project description:Different neurodegenerative diseases are caused by aberrant elongation of repeated glutamine sequences normally found in particular human proteins. Although the proteins involved are ubiquitously distributed in human tissues, toxicity targets only defined neuronal populations. Changes caused by an expanded polyglutamine protein are possibly influenced by endogenous cellular mechanisms, which may be harnessed to produce neuroprotection. Here, we show that ataxin-3, the protein involved in spinocerebellar ataxia type 3, also known as Machado-Joseph disease, causes dendritic and synapse loss in cultured neurons when expanded. We report that S12 of ataxin-3 is phosphorylated in neurons and that mutating this residue so as to mimic a constitutive phosphorylated state counters the neuromorphologic defects observed. In rats stereotaxically injected with expanded ataxin-3-encoding lentiviral vectors, mutation of serine 12 reduces aggregation, neuronal loss, and synapse loss. Our results suggest that S12 plays a role in the pathogenic pathways mediated by polyglutamine-expanded ataxin-3 and that phosphorylation of this residue protects against toxicity.
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Project description:Mutations in the TUBB3 gene, encoding ?-tubulin isotype III, were recently shown to be associated with various neurological syndromes which all have in common the ocular motility disorder, congenital fibrosis of the extraocular muscle type 3 (CFEOM3). Surprisingly and in contrast to previously described TUBA1A and TUBB2B phenotypes, no evidence of dysfunctional neuronal migration and cortical organization was reported. In our study, we report the discovery of six novel missense mutations in the TUBB3 gene, including one fetal case and one homozygous variation, in nine patients that all share cortical disorganization, axonal abnormalities associated with pontocerebellar hypoplasia, but with no ocular motility defects, CFEOM3. These new findings demonstrate that the spectrum of TUBB3-related phenotype is broader than previously described and includes malformations of cortical development (MCD) associated with neuronal migration and differentiation defects, axonal guidance and tract organization impairment. Complementary functional studies revealed that the mutated ?III-tubulin causing the MCD phenotype results in a reduction of heterodimer formation, yet produce correctly formed microtubules (MTs) in mammalian cells. Further to this, we investigated the properties of the MT network in patients' fibroblasts and revealed that MCD mutations can alter the resistance of MTs to depolymerization. Interestingly, this finding contrasts with the increased MT stability observed in the case of CFEOM3-related mutations. These results led us to hypothesize that either MT dynamics or their interactions with various MT-interacting proteins could be differently affected by TUBB3 variations, thus resulting in distinct alteration of downstream processes and therefore explaining the phenotypic diversity of the TUBB3-related spectrum.
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