Cockayne syndrome (CS) is an autossomal human disorder characterized by premature aging along with other symptoms. At the molecular level, CS is characterized by a deficiency in the Transcription-couple DNA repair pathway caused by a mutation mainly in ERCC6 gene and the absence of its functional protein. It has been shown that the presence of DNA damage and the lack of some functional proteins related to DNA repair constitute a barrier for somatic cell reprogramming. Recently, it was demonstrated that one protein involved in Genome Global Repair controls the expression of an important pluripotent gene, highligting its importance for cellular reprogramming.
Evidence for premature aging due to oxidative stress in iPSCs from Cockayne syndrome.
Specimen part, Disease, Cell lineView Samples
Transient expression of two factors, or from Oct4 alone, resulted in efficient generation of human iPSCs. The reprogramming strategy described revealed a potential transcriptional signature for human iPSCs yet retaining the gene expression of donor cells in human reprogrammed cells free of viral and transgene interference.
Transcriptional signature and memory retention of human-induced pluripotent stem cells.
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Stem cells are a potential key strategy for treating neurodegenerative diseases in which the generation of new neurons is critical. A better understanding of the characteristics and molecular properties of neural stem cells (NSC) and differentiated neurons can help in assessing neuronal maturity and possibly in devising better therapeutic strategies. We have therefore performed an in-depth gene expression profiling study of the C17.2 NSC line and primary neurons (PN) derived from embryonic mouse brains. Microarray analysis revealed a neuron-specific gene expression signature that distinguishes PN from NSCs, with elevated levels of transcripts involved in neuronal functions such as neurite development, axon guidance, in PN. The same comparison revealed decreased levels of multiple cytokine transcripts such as IFN, TNF, TGF, and IL. Among the differentially expressed genes, we found a statistically significant enrichment of genes in the ephrin, neurotrophin, CDK5 and actin pathways which control multiple neuronal-specific functions. Furthermore, genes involved in cell cycle were among the most significantly changed in PN. In order to better understand the role of cell cycle arrest in mediating NSCs differentiation, we blocked the cell cycle of NSCs with Mitomycin C (MMC) and examined cellular morphology and gene expression signatures. Although these MMC-treated NSCs displayed a neuronal morphology and expressed some neuronal differentiation marker genes, their gene expression patterns was very different from primary neurons. We conclude that: 1) Fully differentiated primary neurons display a specific neuronal gene expression signature; 2) cell-cycle block in NSC does not induce the formation of fully differentiated neurons; 3) Cytokines such as IFN, TNF, TGF and IL are part of normal NSC function and/or physiology; 4) Signaling pathways of ephrin, neurotrophin, CDK5 and actin, related to major neuronal features, are dynamically enriched in genes showing changes in expression level.
Identification of a neuronal gene expression signature: role of cell cycle arrest in murine neuronal differentiation in vitro.
Sex, Specimen part, Cell lineView Samples
L1 retrotransposons are active elements in the genome, capable of mobilization in neuronal progenitor cells. Previously, we showed that chromatin remodeling during neuronal differentiation allows for a transient stimulation of L1 transcription. The activity of L1 retrotransposons during brain development can impact gene expression and neuronal function. Here we show that L1 neuronal retrotransposition in rodents is increased in the absence of MeCP2, a protein involved in global methylation and human neurodevelopmental diseases. Using neuronal progenitor cells derived from human induced pluripotent stem cells and human tissues, we revealed that Rett syndrome patients, with MeCP2 mutations, have increased susceptibility for L1 retrotransposition. Our data demonstrate that disease-related genetic mutations can influence the frequency of neuronal L1 retrotransposition, thereby increasing brain-specific genetic mosaicism.
A model for neural development and treatment of Rett syndrome using human induced pluripotent stem cells.
Sex, Specimen part, SubjectView Samples
We generated iPS cells with a synthetic self-replicative RNA that expresses four independent reprogramming factors (OCT4, KLF4, SOX2 and either c-MYC or GLIS1). We performed whole genome RNA sequencing (RNA-seq) of iPS cell clones, parental BJ and HUES9 ES cell controls. All iPS cell clones analyzed by RNA-seq showed unsupervised hierarchical clustering and expression signatures characteristic of human HUES9 ES cells that were highly divergent from parental human fibroblasts. Overall design: RNA-seq in two OKS-iM iPS clones (generated from OCT4, KLF4, SOX2 and cMYC expressing RNA replicon), two OKS-iG clones (generated from OCT4, KLF4, SOX2 and GLIS1 expressing RNA replicon), HUES9 and BJ cells.
Efficient generation of human iPSCs by a synthetic self-replicative RNA.
Specimen part, SubjectView Samples
RNA sequencing was performed on RNA isolated from groups of 6 hpf wild type and mecp2-null embryos (n=3 biological replicates per condition with 30 embryos pooled per replicate). DESeq2 analysis was performed using https://usegalaxy.org/ Overall design: Whole embryo mRNA profile of 30 pooled mecp2-null or wild type 6 hpf zebrafish embryos, in triplicate, using the Illumina HiSeq4000 platform
Mecp2 regulates <i>tnfa</i> during zebrafish embryonic development and acute inflammation.
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SETD5, a gene linked to intellectual disability (ID) and autism spectrum disorder (ASD), is a member of the SET-domain family and encodes a putative histone methyltransferase (HMT). To date, the mechanism by which SETD5 haploinsufficiency causes ASD/ID remains an unanswered question. Setd5 is the highly conserved mouse homolog, and although the Setd5 null mouse is embryonic lethal, the heterozygote is viable. Morphological tracing and multi electrode array was used on cultured cortical neurons. MRI was conducted of adult mouse brains and immunohistochemistry of juvenile mouse brains. RNA-Seq was used to investigate gene expression in the developing cortex. Behavioral assays were conducted on adult mice. Setd5+/- cortical neurons displayed significantly reduced synaptic density and neuritic outgrowth in vitro, with corresponding decreases in network activity and synchrony by electrophysiology. A specific subpopulation of fetal Setd5+/- cortical neurons showed altered gene expression of neurodevelopment-related genes. Setd5+/- animals manifested several autism-like behaviors, including hyperactivity, cognitive deficit, and altered social interactions. Anatomical differences were observed in Setd5+/- adult brains, accompanied by a deficit of deep-layer cortical neurons in the developing brain. Our data converge on a picture of abnormal neurodevelopment driven by Setd5 haploinsufficiency, consistent with a highly penetrant risk factor. Overall design: Single cell RNA-Seq of CD24+ CD45- neuronal cells isolated from E18.5 WT or SetD5 +/- mouse fetuses.
Setd5 haploinsufficiency alters neuronal network connectivity and leads to autistic-like behaviors in mice.
Specimen part, Cell line, SubjectView Samples
Objective: Analyze expression patterns of genes located at linkage region of SPOAN syndrome (11q12-13), in order to identify genes differentially expressed in samples of SPOAN individuals compared to healthy controls.
Overexpression of KLC2 due to a homozygous deletion in the non-coding region causes SPOAN syndrome.
Specimen partView Samples
iPSC were obtained from DPC from TRPC6-mut patient, a idiopathic autistic patient and a control. Original DPC and iPSC obtained were submited to expression analysis in order to check if the expression pattern obtained for the iPSC cells were closer related to embyonic cells than to the original DPC
Modeling non-syndromic autism and the impact of TRPC6 disruption in human neurons.
Specimen partView Samples