Project description:We studied the synaptic activity-regulated gene expression response in the human genetic background using cultured human iPSC-derived (hiPSCd) neuronal networks and networks of hiPSCd neurons mixed with mouse primary neurons. Our results confirm that genetic changes affect the synaptic activity-regulated gene program, proposing a functional mechanism how they have driven evolution of human cognitive abilities.
Project description:This experiment comprises RNA-seq data used to study evolutionary differences between humans and mice in neuronal activity-dependent transcriptional responses. Activity-dependent transcriptional responses in developing human stem cell-derived cortical neurons were compared with those induced in developing primary- or stem cell-derived mouse cortical neurons 4 hours after KCl-induced membrane depolarisation. Activity-dependent transcriptional responses were also measured in aneuploid mouse neurons carrying human chromosome 21, allowing study of the regulation of Hsa21 genes, plus their mouse orthologs, side-by-side in the same cellular environment of a mouse primary neuron.
Project description:To identify the activity-induced gene expression programs in inhibitory and excitatory neurons, we analyzed RNA extracted from cultured E14 mouse MGE- and CTX-derived neurons (DIV 10) after these cultures were membrane-depolarized for 0, 1 and 6 hrs with 55mM extracellular KCl. To identify the gene programs regulated in these cells by the activity-induced early-response transcription factor Npas4, we repeated the same experiment in the MGE- and CTX-cultures lacking Npas4 (Npas4-KO). Littermate mouse E14 MGE- or CTX-derived neurons (WT or KO for Npas4) were cultured for 9 days, quieted overnight with TTX and AP-5 and then membrane-depolarized for 0, 1 or 6 hours by raising the extracellular KCl-concentration to 55mM. RNA was then extracted and analyzed using Affymetrix GeneChip Mouse Expression Set 430 2.0 microarray platform.
Project description:Experience-dependent gene transcription is required for nervous system development and function. However, the DNA regulatory elements that control this program of gene expression are not well defined. Here we characterize the enhancers that function across the genome to mediate activity-dependent transcription in neurons. While ~12,000 putative activity-regulated enhancer sequences have previously been identified that are enriched for H3K4me1 and the histone acetyltransferase CBP, we find that this chromatin signature is not sufficient to distinguish which of these regulatory sequences are actively engaged in promoting activity-dependent transcription. We show here that a subset of H3K4me1/CBP positive enhancers that is enriched for H3K27 acetylation (H3K27ac) in vivo, and shows increased H3K27ac upon membrane depolarization of cortical neurons, function to regulate activity-dependent transcription. The function of many of these activity-regulated enhancers appears to be dependent on the binding of FOS, a protein that had previously been thought to interact primarily with the promoters of activity-regulated genes. Furthermore, many of these target genes in cortical neurons encode neuron specific proteins that regulate synaptic development and function. These findings suggest that FOS functions at enhancers to control activity-dependent gene programs that are critical for nervous system function, and provide a resource of activity-dependent enhancers that may give insight into genetic variation that contributes to brain development and disease. Genome-wide maps of H3K27ac and AP1 transcription factors (CFOS, FOSB, JUNB) before and after neuronal activity in mouse cortical neurons.
Project description:We report a genome-wide mapping of DNA G-quadruplexes and histone modifications in living neurons. We used primary cultured neurons from the fetus mouse cortex. Cultured cells were treated with 2 µM Ara-C at DIV3 to prevent the proliferation of mitotic cells and were harvested at DIV10. For iG4 CUT&Tag, a BG4-expressing plasmid was transfected by electroporation at DIV0.
Project description:Mutations in PINK1 and Parkin lead to Parkinson’s disease. Cell culture-based studies have demonstrated that mitochondrial depolarisation induced by chemical uncouplers can activate PINK1 and Parkin activity. Very little is known on mitochondrial depolarisation signalling in post-mitotic neurons. We have established a primary mouse cortical neuron system to investigate mitochondrial depolarisation induced changes in the proteome. We have undertaken proteomic copy-number analysis to characterise the expression levels of all known Parkinson’s proteins in cortical neurons. We have also identified proteins whose expression is up-regulated or down-regulated following mitochondrial depolarisation.
