Project description:Williams-Beuren Syndrome (WBS) is a neurodevelopmental disorder caused by aa 1.5 Mb microdeletion on human chromosome 7. Although the molecular cause of the disorder is well-established, little is known about the global impact of the deletion on gene expression. Here we profiled the transcriptomes of fibroblast cell lines from 8 young girls with WBS, and 9 sex- and age-matched control individuals Keywords: disease state analysis, gene expression profiling
Project description:We have performed comparative transcriptome profile from lymphoblastoid cell lines from four Williams-Beuren syndrome patients and two patients with partial deletions of the region. The goal was to find deregulated genes specifically in WBS versus atypical deletions, and to determine the biological pathways affected in WBS patients.
Project description:Williams-Beuren Syndrome (WBS) is a neurodevelopmental disorder caused by aa 1.5 Mb microdeletion on human chromosome 7. Although the molecular cause of the disorder is well-established, little is known about the global impact of the deletion on gene expression. Here we profiled the transcriptomes of fibroblast cell lines from 8 young girls with WBS, and 9 sex- and age-matched control individuals Keywords: disease state analysis, gene expression profiling Skin fibroblast of 8 WBS and 9 control individuals were obtained from the cell culture collections of the “Centre de Biotechnologie Cellulaire, Hospices Civils de Lyon, Hôpital Debrousse”, Lyon, France. Appropriate informed consent was obtained for each sample by the physicians in charge. Human skin fibroblasts were grown in HAM F-10, supplemented with 10% fetal bovine serum and 1% antibiotics (Invitrogen). Total RNA was prepared using TriZOL Reagent (Invitrogen) and RNeasy Mini Columns (Qiagen) according to the manufacturers’ instructions.
Project description:Copy number variants (CNVs) influence the expression of genes that map not only within the rearrangement, but also to its flanks. To assess the possible mechanism(s) underlying this “neighboring effect”, we compared intrachromosomal interactions and histone modifications in cell lines of patients affected by genomic disorders and control individuals. Using chromosome conformation capture (4C-seq), we observed that a set of genes flanking the Williams-Beuren Syndrome critical region (WBSCR) were often looping together, possibly forming an interacting cluster with each other and the WBSCR. Deletion of the WBSCR disrupts the expression of this group of flanking genes, as well as long-range interactions between them and the rearranged interval. We also pinpointed concomitant changes in histone modifications between samples.We conclude that large genomic rearrangements can lead to chromatin conformation changes that extend far away from the structural variant, thereby possibly modulating expression globally and modifying the phenotype. For example, we determined that the chromatin conformation, histone marks and relative expression levels of the flanking AUTS2 gene, mutations of which are associated with autism and intellectual disabilities, are modified in cell lines from Williams-Beuren syndrome patients. Examination of 4C-seq interaction profile of seven different genes (of which three in duplicate) in 2 different cell lines.
Project description:We have performed comparative transcriptome profile from lymphoblastoid cell lines from four Williams-Beuren syndrome patients and two patients with partial deletions of the region. The goal was to find deregulated genes specifically in WBS versus atypical deletions, and to determine the biological pathways affected in WBS patients. 6 samples were hybridized twice each: once labeled with Cy5 and once labeled with Cy3 (dye-swap). Each sample was hybridized against a pool of five controls of the same gender.
Project description:Copy number variations at 7q11.23 cause neurodevelopmental disorders with shared and opposite manifestations. Deletion leads to Williams-Beuren syndrome (WBS), while duplication causes 7q11.23 microduplication syndrome (7Dup). Converging evidence indicates GTF2I, from the 7q11.23 locus, is a key mediator of the cognitive-behavioral phenotypes associated with WBS and 7Dup. Here we integrate molecular profiling of patient-derived cortical organoids (COs) and transgenic mouse models to dissect 7q11.23 disease mechanisms. Proteomic and transcriptomic profiling of COs revealed opposite dynamics of neural progenitor proliferation and transcriptional imbalances, leading to precocious excitatory neuron production in 7Dup. The accelerated excitatory neuron production in 7Dup COs could be rescued by GTF2I knockdown. Transgenic mice with Gtf2i duplication recapitulated early neuronal differentiation defects and ASD-like behaviors. Remarkably, inhibition of LSD1, a downstream effector of GTF2I, was sufficient to rescue ASD-like phenotypes. We propose that the GTF2I-LSD1 axis constitutes a molecular pathway amenable to therapeutic intervention.
Project description:Copy number variants (CNVs) influence the expression of genes that map not only within the rearrangement, but also to its flanks. To assess the possible mechanism(s) underlying this “neighboring effect”, we compared intrachromosomal interactions and histone modifications in cell lines of patients affected by genomic disorders and control individuals. Using chromosome conformation capture (4C-seq), we observed that a set of genes flanking the Williams-Beuren Syndrome critical region (WBSCR) were often looping together, possibly forming an interacting cluster with each other and the WBSCR. Deletion of the WBSCR disrupts the expression of this group of flanking genes, as well as long-range interactions between them and the rearranged interval. We also pinpointed concomitant changes in histone modifications between samples.We conclude that large genomic rearrangements can lead to chromatin conformation changes that extend far away from the structural variant, thereby possibly modulating expression globally and modifying the phenotype. For example, we determined that the chromatin conformation, histone marks and relative expression levels of the flanking AUTS2 gene, mutations of which are associated with autism and intellectual disabilities, are modified in cell lines from Williams-Beuren syndrome patients.