Project description:Autism spectrum disorder (ASD) is an early onset neurodevelopmental disorder, which is characterized by disturbances of brain function and behavioral deficits in core areas of impaired reciprocal socialization, impairment in communication skills, and repetitive or restrictive interests and behaviors. ASD is known to have a significant genetic risk, but the underlying genetic variation can be attributed to hundreds of genes. The molecular and pathophysiologic basis of ASD remains elusive because of its genetic heterogeneity and complexity, its high comorbidity with other diseases, and the paucity of brain tissue for study. The invasive nature of collecting primary neuronal tissue from patients might be circumvented through reprogramming peripheral cells to induced pluripotent stem cells (iPSCs), which are able to generate live neurons carrying the genetic variants of disease. This breakthrough allows us to access the cellular and molecular phenotypes of patients with âintrinsic autismâ, that is patients without known genetic disorders or identifiable syndromes or malformations. To do this, we studied a relatively homogeneous patient population of boys with intrinsic autism by excluding patients with known genetic disease or recognizable phenotypes or syndromes, as well as those with profound mental retardation or primary seizure disorders. We generated iPSCs from patients with intrinsic autism, their unaffected male siblings and age-, and sex-matched unaffected controls. And these stem cells were subsequently differentiated into electrophysiologically active neurons. The expression profile for autistic and their unaffected siblings' iPSC-derived neurons were compared. A distinct expression profile was found between autism and sib control. The significantly differentially expressed genes (> 2-fold, FDR < 0.05) in autistic iPSC-derived neurons were significantly enriched for processes related to synaptic transmission, such as neuroactive ligand-receptor signaling and extracellular matrix interactions (FDR < 0.05), and were significantly enriched for genes previously associated with ASD (p < 0.05). Our findings suggest approaches such as iPSC-derived neurons will be an important method to obtain tissue for study that appropriately recapitulates the complex dynamics of an autistic neural cell. We generated induced pluripotent stem cells (iPSCs) from male patients with intrinsic autism, their unaffected male siblings, and age-, and sex-matched unaffected controls. And these stem cells were subsequently differentiated into electrophysiologically active neurons following 80 days of post-mitotic neural differentiation. These samples, including fibroblast, iPSC, iPSC-derived neural progenitors (NPC) and iPSC-derived neurons, were analyzed for the change of gene expression profile by whole genome microarray.
Project description:A major challenge to the study and treatment of neurogenetic syndromes is the difficulty in gaining access to live neurons from individuals with these disorders. Although other sources of stem cells are currently available for differentiation into neurons, these can involve invasive procedures and be difficult or expensive to generate limiting their use on a broad scale, especially for rare syndromes which may not be well represented in the local population. Dental pulp stem cells (DPSC) are neural crest derived multipotent stem cells that reside deep the pulp of shed (baby) teeth and have the potential for broad use in the study of neurogenetic disease. Here, we use DPSC-derived neurons to investigate the transcriptional differences between neurotypical controls and Prader-Willi syndrome (PWS) conferred by uniparental disomy (UPD) versus deletion. Additionally, we investigated the increased autism incidence within the UPD genotype by sequencing PW-UPD patients with and without autism. Using this data, we defined a PWS molecular signature and discovered a global reduction in mitochondrial transcripts in the PW-UPD +ASD neurons.
Project description:Autism spectrum disorder (ASD) is an early onset neurodevelopmental disorder, which is characterized by disturbances of brain function and behavioral deficits in core areas of impaired reciprocal socialization, impairment in communication skills, and repetitive or restrictive interests and behaviors. ASD is known to have a significant genetic risk, but the underlying genetic variation can be attributed to hundreds of genes. The molecular and pathophysiologic basis of ASD remains elusive because of its genetic heterogeneity and complexity, its high comorbidity with other diseases, and the paucity of brain tissue for study. The invasive nature of collecting primary neuronal tissue from patients might be circumvented through reprogramming peripheral cells to induced pluripotent stem cells (iPSCs), which are able to generate live neurons carrying the genetic variants of disease. This breakthrough allows us to access the cellular and molecular phenotypes of patients with ‘intrinsic autism’, that is patients without known genetic disorders or identifiable syndromes or malformations. To do this, we studied a relatively homogeneous patient population of boys with intrinsic autism by excluding patients with known genetic disease or recognizable phenotypes or syndromes, as well as those with profound mental retardation or primary seizure disorders. We generated iPSCs from patients with intrinsic autism, their unaffected male siblings and age-, and sex-matched unaffected controls. And these stem cells were subsequently differentiated into electrophysiologically active neurons. The expression profile for autistic and their unaffected siblings' iPSC-derived neurons were compared. A distinct expression profile was found between autism and sib control. The significantly differentially expressed genes (> 2-fold, FDR < 0.05) in autistic iPSC-derived neurons were significantly enriched for processes related to synaptic transmission, such as neuroactive ligand-receptor signaling and extracellular matrix interactions (FDR < 0.05), and were significantly enriched for genes previously associated with ASD (p < 0.05). Our findings suggest approaches such as iPSC-derived neurons will be an important method to obtain tissue for study that appropriately recapitulates the complex dynamics of an autistic neural cell.
Project description:Proteostasis involves a dynamic network of biological pathways that regulate protein synthesis, maintenance, and degradation. As postmitotic cells, neurons are particularly sensitive to environmental changes, and dysfunction in cellular proteostasis can lead to an accumulation of aggregated and misfolded proteins. However, how proteins turnover on a global scale in human neurons is not well understood. In this study, we systematically improved a dynamic SILAC proteomic approach to enable a deep and accurate measurement of protein turnover in human induced pluripotent stem cell (iPSC)-derived cholinergic spinal motor and glutamatergic cortical neurons. Furthermore, we applied this deep proteome turnover method to evaluate how inhibiting the ubiquitin-proteasome and lysosome-autophagy pathway impacts proteostasis in iPSC-derived neurons. Using these datasets, we developed a freely available resource called Neuron Profile, an interactive website for visualizing and querying protein turnover in subcellular locations in human neurons.
Project description:Analysis of TERT-dependent global gene expression changes in iPSC-derived human AD neurons. The hypothesis tested in the present study was that TERT influences the regulation of gene expressions in the iPSC-derived human neurons. Results provide important information of the response of iPSC-derived neurons in presence and absence of TERT induction.
Project description:In this dataset, we studied human dopaminergic neuron differenation from induced pluripotent stem cells (iPSCs). We included the gene expression data obtained from iPSCs and iPSC-derived dopaminergic neurons. This dataset is used to predict chromatin accessibility in iPSCs and iPSC-derived neurons using BIRD (Big data Regression for predicting DNase I hypersensitivity).