Ontology highlight
ABSTRACT:
PROVIDER: PRJNA592218 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:The BAF complex modulates chromatin accessibility. Specific BAF configurations have functional consequences, and subunit switches are essential for cell differentiation. ARID1B and its paralog ARID1A encode for mutually exclusive BAF subunits. De novo ARID1B haploinsufficient mutations cause a neurodevelopmental disorder spectrum, including Coffin-Siris syndrome, which is characterized by neurological and craniofacial features. Here, we reprogrammed ARID1B+/- Coffin-Siris patient-derived skin fibroblasts into iPSCs, and modeled cranial neural crest cell (CNCC) formation. We discovered that ARID1B is active only during the first stage of this process, coinciding with neuroectoderm specification, where it is part of a lineage-specific BAF configuration (ARID1B-BAF), including SMARCA4, and nine additional subunits. ARID1B-BAF acts as a gate-keeper, ensuring exit from pluripotency and lineage commitment, by attenuating NANOG, SOX2 and the thousands of enhancers directly regulated by these two pluripotency factors at the iPSC stage. In iPSCs, these enhancers are maintained active by an ARID1A-containing BAF. At the onset of differentiation, cells transition from ARID1A-BAF to ARID1B-BAF, eliciting attenuation of the NANOG/SOX2 networks, and triggering pluripotency exit. Coffin-Siris patient cells fail to perform the ARID1A/ARID1B switch, and maintain ARID1A-BAF at pluripotency enhancers throughout all stages of CNCC formation. This leads to a persistent and aberrant SOX2 and NANOG activity, which impairs CNCC formation. In fact, despite showing the typical neural crest signature (TFAP2A+, SOX9+), the ARID1B-haploinsufficient CNCCs are also NANOG-positive, in stark contrast with the ARID1B-wt CNCCs, which are NANOG-negative. These findings suggest a connection between ARID1B mutations, neuroectoderm formation, and a pathogenic mechanism for Coffin-Siris syndrome.
2021-10-12 | PXD028557 | Pride
Project description:De-novo ARID1B haploinsufficient mutations cause many developmental disorders characterized by neurological and craniofacial phenotypes, including Coffin-Siris Syndrome. ARID1B and its paralog ARID1A encode for mutually exclusive subunits of the BAF chromatin remodeler, yet their role in cell-fate determination is poorly understood. We discovered a novel neural crest configuration of the BAF complex (ARID1B-BAF), which includes ARID1B, SMARCA4, and eight additional subunits. The ARID1B-BAF regulates lineage commitment upon differentiation cues through attenuation of pluripotency enhancers of the SOX2 network. Consistently, the ARID1B-BAF interacts with SALL4, which is known to have repressing abilities during lineage commitment. In iPSCs, pluripotency enhancers are maintained in active state by cooperation between the pioneer activity of SOX2 and the ARID1A-containing BAF. At the onset of differentiation, ARID1B-BAF replaces ARID1A-BAF at these enhancers, eliciting chromatin repression and coordinating the exit from pluripotency. Coffin-Siris patient cells fail to perform the ARID1A/ARID1B switch, and maintain ARID1A-BAF at the pluripotency enhancers throughout CNCC differentiation. This correlates with aberrant SOX2 binding at the pluripotency enhancers, and failure to reposition SOX2 at the developmental enhancers. SOX2 dysregulation promotes upregulation of the NANOG regulatory network, impairing CNCC differentiation. Intriguingly, the patient with the most extreme molecular phenotype is also affected by a more severe version of the syndrome. These findings have significant biomedical implications, since they suggest a direct connection between ARID1B mutations and developmental disorders.
2021-09-22 | GSE169654 | GEO
Project description:Chromoanagenesis is a descriptive term that encompasses classes of catastrophic mutagenic processes that generate localized and complex chromosome rearrangements in both somatic and germline genomes. Herein we describe a 5-year-old female presenting with a constellation of clinical features consistent with a clinical diagnosis of Coffin-Siris syndrome 1 (CSS1). Initial G-banded karyotyping detected a 90 Mb pericentric and 47 Mb paracentric inversion on a single chromosome. Subsequent analysis using short-read whole genome sequencing, and genomic optical mapping revealed additional inversions, all clustered on chromosome 6, one of them disrupting ARID1B for which haploinsufficiency leading to CSS1. In all, the resolved derivative chromosome architecture presents four de novo inversions, one pericentric and three paracentric, involving six breakpoint junctions in what appears to be a shuffling of genomic material on this chromosome. Each junction was resolved to nucleotide-level resolution with mutational signatures suggestive of non-homologous end joining. The disruption of the gene ARID1B is shown to occur between the 4th and 5th exon of the canonical transcript with subsequent qPCR studies confirming a decrease in ARID1B expression in the patient versus healthy controls. Deciphering the underlying genomic architecture of chromosomal rearrangements and complex structural variants may require multiple technologies and can be critical to elucidating the molecular etiology of a patient’s clinical phenotype or resolving unsolved Mendelian disease cases.
2021-07-22 | GSE180423 | GEO
Project description:Mutations in Brg1 can cause Coffin-Siris syndrome, where a patient had white matter defects and partial agenesis of the corpus callosum; however, Brg1 functions in CNS myelination and remyelination is unsure. We show that PDGFRa expressed prior than NG2, depletion of Brg1 at PDGFRα+ OPC leads to OPC differentiation restriction and myelin defects, also, Brg1 is critical for oligodendrocyte remyelination. Genomic occupancy and transcriptome analyses indicate that Brg1 promotes H3K27me3 and neuronal genes. Thus our findings reveal that Brg1 is a critical epigenetic programmer of CNS myelination and repair through recruiting H3K27me3 and neuronal genes, suggesting potential strategies of therapeutic intervention for Brg1-associated white matter defects.
2024-03-25 | GSE205236 | GEO
Project description:There is growing evidence for the involvement of ARID1B, a SWI/SNF ATP-dependent chromatin remodeling subunit, in a broad range of human disorders. Sequencing studies have recurrently implicated ARID1B haploinsufficiency in autism spectrum disorder (ASD), non-syndromic intellectual disability (ID), corpus callosum agenesis, and short stature. In addition, ARID1B is by far the most common cause of Coffin-Siris Syndrome (CSS), a monogenic developmental delay syndrome characterized by a combination of the neuropsychiatric and physical abnormalities mentioned above. To understand how ARID1B mutations lead to these phenotypes, we generated Arid1b mutant mice, which exhibited physical manifestations of developmental delay and behaviors reminiscent of ASD. In the brain, Arid1b haploinsufficiency resulted in changes in the expression of SWI/SNF- regulated genes implicated in ASD.
2017-06-26 | GSE92238 | GEO
Project description:Coffin-Siris and Nicolaides-Baraitser syndromes (CSS and NCBRS) are Mendelian disorders caused by mutations in subunits of the BAF chromatin remodeling complex. We report overlapping peripheral blood DNA methylation epi-signatures in individuals with various subtypes of CSS (ARID1B, SMARCB1, and SMARCA4) and NCBRS (SMARCA2). We demonstrate that the degree of similarity in the epi-signatures of some CSS subtypes and NCBRS can be greater than that within CSS, indicating a link in the functional basis of the two syndromes. We show that chromosome 6q25 microdeletion syndrome, harboring ARID1B deletions, exhibits a similar CSS/NCBRS methylation profile. Specificity of this epi-signature was confirmed across a wide range of neurodevelopmental conditions including other chromatin remodeling and epigenetic machinery disorders. We demonstrate that a machine-learning model trained on this DNA methylation profile can resolve ambiguous clinical cases, reclassify those with variants of unknown significance, and identify previously undiagnosed subjects through targeted population screening.
2018-11-07 | GSE116992 | GEO