Project description:To determine direct targets of PTBP2-dependent alternative splicing, we performed CLIP-seq analysis of PTBP2 binding in both human cortical tissue and human neurons derived from induced-pluripotent stem cells (iPSC-neurons), and we combine this with splicing analysis following PTBP2 depletion in iPSC-neurons.
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: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:Local microtubule remodeling is critical for axon formation, the first step in establishing neuronal polarity. However, the function of the microtubule organizing centrosomes during the onset of axon formation, is still under debate. Here, we demonstrate that centrosomes play an essential role in controlling axon formation in human induced pluripotent stem cell (iPSC)-derived neurons. Depleting centrioles, the core components of centrosomes, in unpolarized human neuronal stem cells results in various axon developmental defects at later stages, including immature action potential firing, mistargeting of microtubule associated protein Trim46, suppressed expression of growth cone proteins and affected growth cone morphologies. Live-cell imaging of dynamic microtubules reveals that centriole loss prevents axonal microtubule reorganization towards the unique parallel plus-end out microtubule bundles in growing axons. We propose that centrosomes mediate microtubule remodeling during axon specification in human iPSC-derived neurons, thereby setting the foundation for further axon development and function.
Project description:Dopaminergic neurons participate in fundamental physiological processes and are the cell type primarily affected in Parkinson’s disease (PD). Their analysis is challenging due to the intricate nature of their function, their involvement in diverse neurological processes, their heterogeneity and localization in deep brain regions. Consequently, most of the research on the protein dynamics of dopaminergic neurons has been performed in animal cells ex vivo. Here we use iPSC-derived, human mid-brain specific dopaminergic neurons to study general features of their proteome biology. We use dynamic SILAC to measure the half-life of more than 4,300 proteins. We report uniform turnover rates of conserved protein complexes and identify several outliers in the mitochondrial outer membrane and mitophagy pathway. Our study provides a workflow and resource for future applications of quantitative proteomics in iPSC-derived human neurons.
Project description:Early neuronal development is a well-coordinated process in which neuronal stem cells differentiate into polarized neurons. This process has been well studied in classical non-human model systems, but to what extent this is recapitulated in human neurons remains unclear. To study neuronal polarization in human neurons, we cultured human iPSC-derived neurons, characterized early developmental stages, measured electrophysiological responses, and systematically profiled transcriptomic and proteomic dynamics during these steps. We found extensive remodeling of the neuron transcriptome and proteome, with altered mRNA expression of ~1,100 genes and different expression profiles of ~1,500 proteins during neuronal differentiation and polarization. We also identified a distinct stage in axon development marked by an increase in microtubule remodeling and apparent relocation of the axon initial segment from the distal to proximal axon. Our comprehensive characterization and quantitative map of transcriptome and proteome dynamics provides a solid framework for studying polarization in human neurons.