Axonal mRNA in human embryonic stem cell derived neurons
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE84975 | GEO | 2016/07/29
SECONDARY ACCESSION(S): PRJNA335795
REPOSITORIES: GEO
Similar Datasets
Project description:The identification of axonal mRNAs in model organisms has led to the discovery of many axonally translated proteins required for axon guidance and injury response. The extent to which these axonal mRNAs are conserved in humans is unknown. Here we report on the axonal transcriptome of glutamatergic neurons derived from human embryonic stem cells (hESC-neurons) grown in axon isolating microfluidic chambers. We identified mRNAs enriched in axons, representing a functionally unique local transcriptome as compared to the whole neuron transcriptome. Further, we found that the enriched functional categories within high confidence axonal transcripts resemble those in the axonal transcriptome of rat cortical neurons. Comparing our list of human axonal transcripts to similar datasets generated from embryonic and adult rat dorsal root ganglia and rat cortical neurons we found 60 mRNAs common to all four neuron types. We found that over half of these genes are associated with neurological phenotypes or diseases in model organisms and human. This data provides an important resource for studying local mRNA translation in human axons and has the potential to reveal both conserved and unique axonal mechanisms across species and neuronal types. We analyzed the axonal and whole hESC-neuron transcriptome in triplicate using the Affymetrix Human Gene 2.0 ST Array platform.
2016-07-29 | E-GEOD-84975 | biostudies-arrayexpress
Project description:Local protein synthesis in sensory neuron axons is necessary for axonal regeneration with the efficiency of regeneration decreasing with age. Because the full repertoire of transcripts in embryonic and adult rat sensory axons is unknown we asked how the pool of mRNAs dynamically changes during ageing. We isolated mRNA from pure axons and growth cones devoid of non-neuronal or cell body contamination. Genome-wide microarray analysis reveals that a previously unappreciated number of transcripts are localised in sensory axons and that this repertoire changes during development toward adulthood. Embryonic sensory axons are enriched in transcripts encoding cytoskeletal-related proteins with a role in axonal outgrowth. Surprisingly, adult axons are highly enriched in mRNAs encoding immune molecules with a role in nociception. To validate our experimental approach we show that Tubulin-beta3 mRNA is present only in embryonic axons where it is locally synthesised. In summary, we show that the population of axonal mRNAs dynamically changes during development, which may partly contribute to the intrinsic capacity of axons at different ages to regenerate after injury and to modulate pain. Pure axonal RNA were extracted from the axons of embryonic and adult dorsal root ganglion neurons, each with 5 biological replicates. The axonal transcriptomes were analysed using Affymetrix Rat Genome 230 2.0 Arrays.
2010-11-23 | E-GEOD-22638 | biostudies-arrayexpress
Project description:We have conducted quantitative proteomic analyses of the axons of cultured rat cortical neurons. Axons are isolated by using glass chips that enable the axons and their cell bodies of neurons to grow in separated regions on the chip surface. Proteins extracted from the isolated axons, as well as those extracted from whole cortical neurons are subjected to two-dimensional liquid chromatography (2D-LC)-mass spectrometry (MS)-MS analyses. The abundances of proteins in the axon are found to be strongly correlated with their average abundances in whole neurons. Based upon these data, a quantitative description of the protein distribution among various subcellular structures in the axon has been generated. The proteins extracted from the axons and whole neurons are also subjected to stable isotope dimethyl labeling reaction and then to 2D-LC-MS/MS analysis. Proteins enriched in the axon compartment of rat cortical neurons are thus identified.
2018-04-17 | PXD005527 | Pride
Project description:The subcellular localization of specific mRNAs is an evolutionary conserved mechanism that underlies the establishment of cellular polarity and specialized cell functions. In neurons, mRNA trafficking and local protein translation in dendrites provides an important mechanism that mediates synaptic development and plasticity. The significance of mRNA targeting and protein synthesis in axons, however, is still unclear. Only a small number of transcripts have been identified in axons to date, and their contribution to axon growth and neuronal survival remains largely unknown. Here, we report the results of a novel screen that allowed the separate identification of mRNAs localized in cell bodies and in axons of developing neurons. Using compartmentalized cultures of sympathetic neurons and Sequential Analysis of Gene Expression (SAGE), the screen identified more than 200 axonal mRNAs, including ones that encode cytoskeletal proteins and proteins that function in neural development and signal transduction. Importantly, several classes of transcripts were selectively enriched in axons, indicating that an active process drives the targeting of specific mRNAs from the cell bodies to the axons. This study is the first comprehensive and unbiased analysis of mRNA localization in subcellular domains of any neuronal cell type. We used compartmentalized chambers to culture neonatal rat sympathetic neurons (Campenot, 1977). In these cultures, the cell bodies are separated from the distal axons by a 1 mm wide Teflon divider, which maintains the cell bodies and axon terminals in separate fluid compartments. Primary rat sympathetic neurons are especially suitable for compartmentalized culture because they can be grown as a highly homogeneous population without glial cells. Neurons were seeded in the central compartment with nerve growth factor (NGF), and after a few days, the NGF was lowered in this compartment and supplied only to the peripheral compartment to stimulate axon growth. The anti-mitotic agent cytosine arabinoside C (Ara-C) was added to both compartments to remove non-neuronal cells. mRNA was then isolated after 12 days in culture (DIV) from cell body or axon compartments. As the initial mRNA content in axons was not sufficient to perform the SAGE analysis, both axon and cell body mRNAs were subjected to two rounds of linear amplification to obtain antisense RNA (aRNA). The amplified aRNA was then reverse transcribed and second strand synthesis was performed to proceed with the SAGE assay using the LongSAGE kit (Invitrogen) according to the manufacturer’s protocol.
2010-01-30 | E-GEOD-13788 | biostudies-arrayexpress
Project description:Retrograde signaling from axon to soma activates intrinsic regeneration mechanisms in lesioned peripheral sensory neurons; however, the links between axonal injury signaling and the cell body response are not well understood. Here, we used phosphoproteomics and microarrays to implicate ~900 phosphoproteins in retrograde injury signaling in rat sciatic nerve axons in vivo and ~4500 transcripts in the in vivo response to injury in the dorsal root ganglia. Computational analyses of these data sets identified ~400 redundant axonal signaling networks connected to 39 transcription factors implicated in the sensory neuron response to axonal injury. Experimental perturbation of individual overrepresented signaling hub proteins, including Abl, AKT, p38, and protein kinase C, affected neurite outgrowth in sensory neurons. Paradoxically, however, combined perturbation of Abl together with other hub proteins had a reduced effect relative to perturbation of individual proteins. Our data indicate that nerve injury responses are controlled by multiple regulatory components, and suggest that network redundancies provide robustness to the injury response Microarrays were run on mRNA extracted from adult rat L4 and L5 DRGs cells after 1,3,8,12,16,18,24, and 28 hours after a sciatic nerve (proximal and distal) lesion.
2010-12-29 | E-GEOD-26350 | biostudies-arrayexpress
Project description:Local mRNA translation mediates the adaptive responses of axons to extrinsic signals but direct evidence that it occurs in mammalian CNS axons in vivo is scant. We developed an axon-TRAP-RiboTag approach in mouse that allows deep-sequencing analysis of ribosome-bound mRNAs in the retinal ganglion cell axons of the developing and adult retinotectal projection in vivo. The embryonic-to-postnatal axonal translatome comprises an evolving subset of enriched genes with axon-specific roles suggesting distinct steps in axon wiring, such as elongation, pruning and synaptogenesis. Adult axons, remarkably, have a complex translatome with strong links to axon survival, neurotransmission and neurodegenerative disease. Translationally co-regulated mRNA subsets share common upstream regulators, and novel sequence elements generated by alternative splicing that promote axonal mRNA translation. Our results indicate that intricate regulation of compartment-specific mRNA translation in mammalian CNS axons supports the formation and maintenance of neural circuits in vivo. The profiling of ribosome-bound mRNAs in mouse retinal ganglion cell axons at 4 different developmental stages
2016-06-16 | E-GEOD-79352 | biostudies-arrayexpress
Project description:RNA localization is a regulatory mechanism that is conserved from bacteria to mammals. Yet, little is known about the mechanism and the logic that govern the distribution of RNA transcripts within the cell. Here we present a novel organ culture system, which enables the isolation of RNA specifically from NGF dependent re-growing peripheral axons of mouse embryo sensory neurons. In combination with massive parallel sequencing technology, we determine the sub-cellular localization of most transcripts in the transcriptome. We found that the axon is enriched in mRNAs that encode secreted proteins, transcription factors and the translation machinery. In contrast, the axon was largely depleted from mRNAs encoding transmembrane proteins, a particularly interesting finding, since many of these gene products are specifically expressed in the tip of the axon at the protein level. Comparison of the mitochondrial mRNAs encoded in the nucleus with those encoded in the mitochondria, uncovered completely different localization pattern, with the latter much enriched in the axon fraction. This discovery is intriguing since the protein products encoded by the nuclear and mitochondrial genome form large co-complexes. Finally, focusing on alternative splice variants that are specific to axonal fractions, we find short sequence motifs that are enriched in the axonal transcriptome. Together our findings shed light on the extensive role of RNA localization and its characteristics. For each RNA sample, Spinal Cords\ DRGs were dissected from 40 E13.5 embryos and cultured for 48H. Total RNA was extracted from whole DRG and Peripheral axons. Poly-A enriched. In duplicates, using GAIIx. Read length - 80nt.
2013-10-24 | E-GEOD-51572 | biostudies-arrayexpress
Project description:Ribosome assembly occurs mainly in the nucleolus yet recent studies have revealed robust enrichment and translation of mRNAs encoding many ribosomal proteins (RPs) in axons, far away from neuronal cell bodies. Here, we report a physical and functional interaction between locally synthesized RPs and ribosomes in the axon. We show that axonal RP translation is regulated through a novel sequence motif, CUIC, that forms an RNA-loop structure in the region immediately upstream of the initiation codon. Using imaging and subcellular proteomics techniques, we show that RPs synthesized in axons join axonal ribosomes in a nucleolus-independent fashion. Inhibition of axonal CUIC-regulated RP translation causes a significant decline in local translation activity and markedly reduces axon branching in the brain, revealing the physiological relevance of axonal RP synthesis in vivo. These results suggest that axonal translation supplies cytoplasmic RPs to maintain/modify local ribosomal function far from the nucleolus in neurons.
2019-12-09 | PXD015574 | Pride
Project description:Local protein synthesis in sensory neuron axons is necessary for axonal regeneration with the efficiency of regeneration decreasing with age. Because the full repertoire of transcripts in embryonic and adult rat sensory axons is unknown we asked how the pool of mRNAs dynamically changes during ageing. We isolated mRNA from pure axons and growth cones devoid of non-neuronal or cell body contamination. Genome-wide microarray analysis reveals that a previously unappreciated number of transcripts are localised in sensory axons and that this repertoire changes during development toward adulthood. Embryonic sensory axons are enriched in transcripts encoding cytoskeletal-related proteins with a role in axonal outgrowth. Surprisingly, adult axons are highly enriched in mRNAs encoding immune molecules with a role in nociception. To validate our experimental approach we show that Tubulin-beta3 mRNA is present only in embryonic axons where it is locally synthesised. In summary, we show that the population of axonal mRNAs dynamically changes during development, which may partly contribute to the intrinsic capacity of axons at different ages to regenerate after injury and to modulate pain.
2010-11-23 | GSE22638 | GEO
Project description:Spinal motor axons traverse large distances to innervate target muscle, and thus require local control of cellular events for proper functioning of the distal axon. To interrogate axon-specific processes we developed Axon-seq, a refined method incorporating microfluidic devices and stringent bioinformatic quality controls. Axon-seq demonstrates improved sensitivity and accuracy in whole-transcriptome sequencing of axons compared to previously published studies. Importantly, we show that axon transcriptomes are distinct from those of somas, displaying fewer detected genes and no contaminating astrocytic markers. We identified >5,000 transcripts in stem cell-derived spinal motor axons required for local oxidative energy production and ribosome generation. Axons contained unique transcription factor mRNAs, e.g. Ybx1, with implications for local axonal functions. Cross-comparison with existing mouse motor axon datasets, as well as our own human motor axon data identified a common axon transcriptome. As motor axons degenerate in amyotrophic lateral sclerosis (ALS), we investigated their response to the disease-causing SOD1G93A mutation, identifying 121 ALS-dysregulated transcripts. Several of these are implicated in axonal and dendritic outgrowth, including Nrp1, Dbn1, and Nek1, a known ALS-causing gene. In conclusion, Axon-seq proves a robust and improved method for RNA-seq of axons, furthers our understanding of peripheral axon biology, and identifies novel therapeutic targets to maintain neural connectivity in disease.
2018-12-11 | GSE121069 | GEO