Transcriptional control of retinal ganglion cell death after axonal injury
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE168789 | GEO | 2022/03/24
REPOSITORIES: GEO
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Project description:We used optic nerve injury as a model to study early signaling events in the neuronal soma following axonal injury. Optic nerve injury results in the selective death of retinal ganglion cells (RGCs). The time course of cell death takes place over a period of days with the earliest detection of RGC death at about 48 hr post injury. We hypothesized that in the period immediately following axonal injury, there are changes in the soma that signal surrounding glia and neurons and that start programmed cell death. In the current study, we investigated early changes in cellular signaling and gene expression that occur within the first 6 hrs post optic nerve injury. We detected differences in phosphoproteins and gene expression within this time period that we used to interpret temporal events. Our studies revealed that the entire retina has been signaled by the RGC soma within 30 min after optic nerve injury and that pathways that modulate cell death are likely to be active in RGCs within 6 hrs following axonal injury Experiment Overall Design: In the treated animals, axons of the optic nerve were crushed with fine forceps for 10 sec, 1 mm posterior to the globe, under direct visualization, within an intact meningeal sheath. Controls were contralateral eyes from the same animals in each group that had not been injured. After 6 hr eyes were enucleated and processed for tissue sectionin
2008-10-25 | E-GEOD-11862 | biostudies-arrayexpress
Project description:We used optic nerve injury as a model to study early signaling events in the neuronal soma following axonal injury. Optic nerve injury results in the selective death of retinal ganglion cells (RGCs). The time course of cell death takes place over a period of days with the earliest detection of RGC death at about 48 hr post injury. We hypothesized that in the period immediately following axonal injury, there are changes in the soma that signal surrounding glia and neurons and that start programmed cell death. In the current study, we investigated early changes in cellular signaling and gene expression that occur within the first 6 hrs post optic nerve injury. We detected differences in phosphoproteins and gene expression within this time period that we used to interpret temporal events. Our studies revealed that the entire retina has been signaled by the RGC soma within 30 min after optic nerve injury and that pathways that modulate cell death are likely to be active in RGCs within 6 hrs following axonal injury Keywords: Stress Response
2008-09-01 | GSE11862 | GEO
Project description:Purpose: The purpose of this study was to use RNA-seq to investigate the molecular mechanisms of damage in the early stages of the response to axonal injury, before the onset of RGC death. Methods: 12-week-old wild-type (WT) mice were used in this study. The experiment group underwent an optic nerve crush (ONC) procedure to induce axonal injury in the right eye, and the control group underwent a sham procedure. Retinal mRNA profiles were generated by deep sequencing, in triplicate, using IlluminaHiseq2000. The sequence reads were analyzed by CLC genomics workbench and R software. qRT–PCR validation was performed using TaqMan assays. Results: Using an optimized data analysis workflow, we mapped about 66 million sequence reads per sample to the mouse genome (build mm9). Differential gene expression analysis showed that endoplasmic reticulum stress-related genes and antioxidative response-related genes have been shown to be significantly upregulated 2 days after ONC. Conclusions: Our study represents the first detailed analysis of retinal transcriptomes in the early stages after axonal injury. Our results indicated that ER stress plays a key role under these conditions. Furthermore, the antioxidative defense and immune responses occurred concurrently in the early stages after axonal injury. We believe that our study will lead to a better understanding of and insight into the molecular mechanisms underlying RGC death after axonal injury. Retinal mRNA profiles of 12 week-old wild type (WT) after ONC or sham were generated by deep sequencing, in triplicate, using Illumina Hiseq2000.
2014-02-21 | E-GEOD-55228 | 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:Transcriptional control of retinal ganglion cell death after axonal injury
| PRJNA713995 | ENA
Project description:Traumatic brain injury (TBI) strongly correlates with neurodegenerative disease. However, it remains unclear which neurodegenerative mechanisms are intrinsic to the brain itself and which strategies most potently mitigate these processes, particularly in individuals genetically predisposed to neurodegeneration. We developed a high-intensity ultrasound platform to inflict mechanical injury to iPSC-derived cortical organoids. Mechanically injured organoids elicit several classic hallmarks of TBI including neuron death, tau phosphorylation, and TDP-43 phosphorylation and nuclear egress. We found that deep layer excitatory neurons were particularly vulnerable to injury and that TDP-43 proteinopathy promotes loss-of-function and cell death. Injured organoids derived from C9ORF72 amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) patients displayed exacerbated TDP-43 dysfunction. Using genome-wide CRISPR interference screening, we identified a mechanosensory channel, KCNJ2, whose inhibition potently mitigated neurodegenerative processes in vitro and in vivo, including in C9ORF72 ALS/FTD organoids. Thus, targeting KCNJ2 may reduce acute neuron death after brain injury, and we present a scalable, genetically-flexible cerebral organoid model that may enable identification of additional modifiers downstream of mechanical stress.
2024-03-04 | GSE259432 | GEO
Project description:Traumatic brain injury (TBI) strongly correlates with neurodegenerative disease. However, it remains unclear which neurodegenerative mechanisms are intrinsic to the brain itself and which strategies most potently mitigate these processes, particularly in individuals genetically predisposed to neurodegeneration. We developed a high-intensity ultrasound platform to inflict mechanical injury to iPSC-derived cortical organoids. Mechanically injured organoids elicit several classic hallmarks of TBI including neuron death, tau phosphorylation, and TDP-43 phosphorylation and nuclear egress. We found that deep layer excitatory neurons were particularly vulnerable to injury and that TDP-43 proteinopathy promotes loss-of-function and cell death. Injured organoids derived from C9ORF72 amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) patients displayed exacerbated TDP-43 dysfunction. Using genome-wide CRISPR interference screening, we identified a mechanosensory channel, KCNJ2, whose inhibition potently mitigated neurodegenerative processes in vitro and in vivo, including in C9ORF72 ALS/FTD organoids. Thus, targeting KCNJ2 may reduce acute neuron death after brain injury, and we present a scalable, genetically-flexible cerebral organoid model that may enable identification of additional modifiers downstream of mechanical stress.
2024-03-04 | GSE260532 | GEO
Project description:After nerve injury, myelin and Remak Schwann cells reprogram to repair cells specialized for regeneration. Normally providing strong regenerative support, these cells fail in aging animals, and during the chronic denervation that results from slow axon growth. This impairs axonal regeneration and causes a significant clinical problem. We find that aging and chronically denervated repair cells express reduced c-Jun protein and the regenerative support provided by these cells is also reduced. In both cases, genetically restoring Schwann cell c-Jun levels restores regeneration to that in controls. We identify potential gene candidates mediating this effect and implicate Shh in the control of Schwann cell c-Jun levels. These experiments reveal that a common mechanism, reduced c-Jun in repair cells, underlies two major reasons for regeneration failure in the PNS. They underscore the central importance of Schwann cell c-Jun as a regulator of nerve repair, and point to molecular pathways that can be manipulated for improving the clinical outcome of nerve injuries.
2020-10-14 | E-MTAB-9640 | biostudies-arrayexpress
Project description:Salamanders have the remarkable ability to functionally regenerate after spinal cord transection. In response to injury, GFAP+ glial cells in the axolotl spinal cord proliferate and migrate to replace the missing neural tube and create a permissive environment for axon regeneration. Molecular pathways that regulate the pro-regenerative axolotl glial cell response are poorly understood. Here we show axolotl glial cells up-regulate AP-1cFos/JunB after injury, which promotes a pro-regenerative glial cell response. Axolotl glial cells directly repress c-Jun expression via up-regulation of miR-200a. Inhibition of miR-200a during regeneration causes defects in axonal regrowth and transcriptomic analysis revealed that miR-200a inhibition leads to differential regulation of genes involved with reactive gliosis, the glial scar, ECM remodeling and axon guidance. This work identifies a novel role for miR-200a in inhibiting reactive gliosis in glial cell in axolotl during spinal cord regeneration
2019-03-19 | GSE122939 | GEO
Project description:Background: Mechanical ventilation causes ventilator-induced lung injury in animals and humans. Mitogen-activated protein kinases have been implicated in ventilator-induced lung injury though their functional significance remains incomplete. We characterize the role of p38 mitogen-activated protein kinase/ mitogen activated protein kinase kinase-3 and c-Jun-NH2-terminal kinase-1 in ventilator-induced lung injury and investigate novel independent mechanisms contributing to lung injury during mechanical ventilation. Methodology and Principle Findings: C57/BL6 wild-type mice and mice genetically deleted for mitogen-activated protein kinase kinase-3 (mkk-3-/-) or c-Jun-NH2-terminal kinase-1 (jnk1-/-) were ventilated, and lung injury parameters were assessed. We demonstrate that mkk3-/- or jnk1-/- mice displayed significantly reduced inflammatory lung injury and apoptosis relative to wild-type mice. Since jnk1-/- mice were highly resistant to ventilator-induced lung injury, we performed comprehensive gene expression profiling of ventilated wild-type or jnk1-/- mice to identify novel candidate genes which may play critical roles in the pathogenesis of ventilator-induced lung injury. Microarray analysis revealed many novel genes differentially expressed by ventilation including matrix metalloproteinase-8 (MMP8) and GADD45a. Functional characterization of MMP8 revealed that mmp8-/- mice were sensitized to ventilator-induced lung injury with increased lung vascular permeability. Conclusions: We demonstrate that mitogen-activated protein kinase pathways mediate inflammatory lung injury during ventilator-induced lung injury. C-Jun-NH2-terminal kinase was also involved in alveolo-capillary leakage and edema formation, whereas MMP8 inhibited alveolo-capillary protein leakage. Keywords: response to injury, genetically modified mouse
2007-05-08 | GSE7742 | GEO