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:We performed RNA-seq experiments on two samples (cortical neurons and spinal motor neurons) from normal induced pluripotent stem cells (iPSCs), and another two samples (cortical neurons and spinal motor neurons) derived from SPG3A (an early onset form of hereditary spastic paraplegia) iPSCs. This initial experiment is to test the system and set up a baseline for future studies. Cortical projection neurons and spinal motor neurons were differentiated from same batch of iPSCs in parallel to minimize variations. The differentiation of cortical neurons and spinal motor neurons are based on protocols well-established in our group.
Project description:The order in the abundance of exosomal mRNAs was not the same with that of the source cellular mRNAs in human iPSC-derived motor neurons.
Project description:Amyotrophic lateral sclerosis (ALS) is a severe neurodegenerative condition characterized by loss of motor neurons in the brain and spinal cord. Expansions of a hexanucleotide repeat (GGGGCC) in the noncoding region of the C9ORF72 gene are the most common cause of the familial form of ALS (C9-ALS), as well as frontotemporal lobar degeneration and other neurological diseases. How the repeat expansion causes disease remains unclear, with both loss of function (haploinsufficiency) and gain of function (either toxic RNA or protein products) proposed. We report a cellular model of C9-ALS with motor neurons differentiated from induced pluripotent stem cells (iPSCs) derived from ALS patients carrying the C9ORF72 repeat expansion. No significant loss of C9ORF72 expression was observed, and knockdown of the transcript was not toxic to cultured human motor neurons. Transcription of the repeat was increased, leading to accumulation of GGGGCC repeat–containing RNA foci selectively in C9-ALS iPSC-derived motor neurons. Repeat-containing RNA foci colocalized with hnRNPA1 and Pur-?, suggesting that they may be able to alter RNA metabolism. C9-ALS motor neurons showed altered expression of genes involved in membrane excitability including DPP6, and demonstrated a diminished capacity to fire continuous spikes upon depolarization compared to control motor neurons. Antisense oligonucleotides targeting the C9ORF72 transcript suppressed RNA foci formation and reversed gene expression alterations in C9-ALS motor neurons. These data show that patient-derived motor neurons can be used to delineate pathogenic events in ALS. Transcriptome profiling from iPSC derived motor neurons compared to controls
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).
Project description:We studied human induced pluripotent stem cells (iPSCs)-derived dopaminergic (DA) neuron populations carrying CNVs of 16p11.2 duplication and 16p11.2 deletion.
Previously, healthy human iPSCs were edited using CRISPR-Cas9 method to produce isogenic lines with 16p11.2 deletion or 16p11.2 duplication. We differentiated these
isogenic iPSC lines into neural precursor cells and dopaminergic neurons and collected RNA samples for gene expression analyses with RNA sequencing. Our aim was to
identify differences in the expression of synaptic markers, neuronal differentiation markers, and neuron specific receptors that affect functionality of the neurons with 16p11.2
CNVs compared to isogenic control lines. We also studied physiological properties of these isogenic iPSC-derived DA neurons with 16p11.2 CNVs. In addition, we studied
expression and activation of a specific molecular pathway KCTD13-RHOA in the iPSC derived DA neuron populations with 16p11.2 CNVs.