Project description:Monogenic neurodevelopmental disorders provide key insights into the pathogenesis of disease and help us understand how specific genes control the development of the human brain. Timothy syndrome is caused by a missense mutation in the L-type calcium channel Cav1.2 that is associated with developmental delay and autism. We generated cortical neuronal precursor cells and neurons from induced pluripotent stem cells derived from individuals with Timothy syndrome. Cells from these individuals have defects in calcium (Ca2+) signaling and activity-dependent gene expression and show abnormalities in differentiation. Neurons from individuals with Timothy syndrome show increased expression of markers of the upper cortical layer and decreased expression of callosal projection markers. In addition, the mutation that causes Timothy syndrome leads to an increase in the production of neurons that synthesize norepinephrine and dopamine. This phenotype can be reversed by treatment with roscovitine, a cyclin-dependent kinase and atypical L-type–channel blocker. These findings provide strong evidence that Cav1.2 regulates the differentiation of cortical neurons in humans and offer new insights into the causes of autism in individuals with Timothy syndrome. Total RNA was isolated from control and TS cells: fibroblasts, iPSCs, neurospheres (at day 7 in suspension), neurons at rest (day 45 of differentiation) and neurons kept in 67mM KCl for 9h. For sample titles, D1,D2 and D3 represent independent differentiation experiments. The number after - represents the iPSC cell line number. GSE25542_non-normalized.txt.gz contains data for 5 outliers.
Project description:Monogenic neurodevelopmental disorders provide key insights into the pathogenesis of disease and help us understand how specific genes control the development of the human brain. Timothy syndrome is caused by a missense mutation in the L-type calcium channel Cav1.2 that is associated with developmental delay and autism. We generated cortical neuronal precursor cells and neurons from induced pluripotent stem cells derived from individuals with Timothy syndrome. Cells from these individuals have defects in calcium (Ca2+) signaling and activity-dependent gene expression and show abnormalities in differentiation. Neurons from individuals with Timothy syndrome show increased expression of markers of the upper cortical layer and decreased expression of callosal projection markers. In addition, the mutation that causes Timothy syndrome leads to an increase in the production of neurons that synthesize norepinephrine and dopamine. This phenotype can be reversed by treatment with roscovitine, a cyclin-dependent kinase and atypical L-type–channel blocker. These findings provide strong evidence that Cav1.2 regulates the differentiation of cortical neurons in humans and offer new insights into the causes of autism in individuals with Timothy syndrome.
Project description:We recently identified heterozygous deletions of the gene TSHZ3, which encodes a Zn-finger transcription factor, in patients with a syndrome including autistic features and provided evidence in mice for a link between Tshz3 haploinsufficiency, defects in cortical projection neurons (CPNs) and autism spectrum disorder (ASD)-like abnormalities. To get more insight into when and where TSHZ3 is required for the proper development of the brain, we generated and characterized a novel mouse model of conditional Tshz3 deletion in projection neurons from postnatal day 2-3 onward. These mice exhibit altered cortical expression of genes encoding for synaptic components, electrophysiological and synaptic changes in layer 5 CPNs, impaired corticostriatal glutamate transmission and plasticity, as well as strong ASD-relevant behavioral deficits. These data, by revealing a crucial postnatal role of TSHZ3 in the development and function of the corticostriatal circuitry that might be determinant for ASD pathogenesis, offer a novel ASD model and further open the possibility for an early postnatal therapeutic window for the syndrome linked to TSHZ3 haploinsufficiency.
Project description:We recently identified heterozygous deletions of the gene TSHZ3, which encodes a Zn-finger transcription factor, in patients with a syndrome including autistic features and provided evidence in mice for a link between Tshz3 haploinsufficiency, defects in cortical projection neurons (CPNs) and autism spectrum disorder (ASD)-like abnormalities. To get more insight into when and where TSHZ3 is required for the proper development of the brain, we generated and characterized a novel mouse model of conditional Tshz3 deletion in projection neurons from postnatal day 2-3 onward. These mice exhibit altered striatal expression of genes encoding for synaptic components, electrophysiological and synaptic changes in striatal cholinergic interneurons, , as well as ASD-relevant behavioral deficits. These data, by revealing a crucial postnatal role of TSHZ3 in the development and function of the corticostriatal circuitry that might be determinant for ASD pathogenesis, offer a novel ASD model and further open the possibility for an early postnatal therapeutic window for the syndrome linked to TSHZ3 haploinsufficiency.
Project description:TSHZ3, which encodes a zinc-finger transcription factor, was recently positioned as a hub gene in a module of genes with the highest expression in the developing human neocortex, but its functions remained unknown. Here, we identify TSHZ3 as the critical region for a syndrome associated with heterozygous deletions at 19q12q13.11, which includes autism spectrum disorder (ASD). In Tshz3 null mice, differentially expressed genes include layer-specific markers of cerebral cortical projection neurons (CPNs) and their human orthologues are strongly associated with ASD. Furthermore, heterozygous Tshz3-deficient mice show functional changes at synapses established by CPNs and exhibit core ASD-like behavioral abnormalities. These findings reveal essential roles for Tshz3 in CPN development and function, whose alterations can account for ASD in the newly-defined TSHZ3 deletion syndrome.
Project description:This SuperSeries is composed of the following subset Series:; GSE2039: FACS purified cortical projection neurons; GSE17783: Analysis of gene expression in FACS-purified cortical projection neurons using Affymetrix 430 2.0 microarrays Experiment Overall Design: Refer to individual Series
Project description:The cortical area map is initially patterned by transcription factor (TF) gradients in the neocortical primordium, which define a protomap in the embryonic ventricular zone (VZ). However, mechanisms that propagate regional identity from VZ progenitors to cortical plate (CP) neurons are unknown. Here we show that the VZ, subventricular zone (SVZ), and CP contain distinct molecular maps of regional identity, reflecting different gene expression gradients in radial glia progenitors, intermediate progenitors, and projection neurons, respectively. The intermediate map in SVZ is modulated by Eomes (also known as Tbr2), a T-box TF. Eomes inactivation caused rostrocaudal shifts in SVZ and CP gene expression, with loss of corticospinal axons and gain of corticotectal projections. These findings suggest that cortical areas and connections are shaped by sequential maps of regional identity, propagated by the Pax6 ? Eomes ? Tbr1 TF cascade. In humans, PAX6, EOMES, and TBR1 have been linked to intellectual disability and autism. To determine the role of Eomes in the propagation of the protomap to cortical plate neurons, used microarray analysis of E14.5 cortex from five wild type and three Eomes knockout mice.
Project description:Developmental neuron death plays a pivotal role in refining organization and wiring during neocortex formation. Aberrant regulation of this process results in neurodevelopmental disorders including impaired learning and memory. Underlying molecular pathways are incompletely determined. Loss of Bcl11a in cortical projection neurons induces pronounced cell death in upper-layer cortical projection neurons during postnatal corticogenesis. We used this genetic model to explore genetic mechanisms by which developmental neuron death is controlled. Unexpectedly, we found Bcl6, previously shown to be involved in transition of cortical neurons from progenitor to postmitotic differentiation state to provide a major check point regulating neuron survival during late cortical development. We show that Bcl11a is a direct transcriptional regulator of Bcl6. Deletion of Bcl6 exerts death of cortical projection neurons. In turn, reintroduction of Bcl6 into Bcl11a mutants prevents induction of cell death in these neurons. Together, our data identify a novel Bcl11a/Bcl6-dependent molecular pathway in regulation of developmental cell death during corticogenesis.