Mitf is a Schwann Cell Sensor of Axonal Integrity that Drives Nerve Repair
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE218702 | GEO | 2024/01/01
REPOSITORIES: GEO
Similar Datasets
Project description:Hereditary Motor and Sensory Neuropathies (HMSN) are the most common inherited peripheral neuropathies and comprise a group of genetically heterogeneous diseases. We study the genetic defects causing three demyelinating disorders: HMSN1A, HMSN-LOM and congenital cateracts facial dysmophism neuropathy (CCFDN) syndrome, which are caused by mutations in PMP22, NDRG1 and CTDP1, respectively. The function and patho-mechanisms of these genes is still unknown. To identify effects downstream of the mutations, thereby possibly involved in the disease process, we used Serial expression of gene expression (SAGE) and microarray analysis. We analyzed human Schwann cell lines from three normal subjects, one HMSN-LOM patient, two HMSN-1A patients and two CCFDN patients and compared our data to a recent dataset of human Schwann cells (4 normal subjects passage 1 vs. 3, GDS1869/GSE4030 M.B. Bunge, 2006). We excluded genes that were not consistently regulated between biological and technical replicates and genes that were found to be influenced by passage number (p<0.05). Comparing expression profiles of demyelinating neuropathies with different mutations we identified: 1. expression signatures specific for each genotype. 2. Genes commonly (dys)regulated in all screened neuropathies. Interestingly, these include genes that play a role in reorganization of sodium channels in central and peripheral nerves (S100A10, CD90), or extracellular matrix remodeling (e.g. TGFBI, SERPINE1, THBS1). We also found high up-regulation of genes involved in Schwann cell lineage and in particular, genes that are associated with an immature or pre-myelinating Schwann cell phenotype (i.e. Sox2, Sox10, COL18A1, TFAP2A, Pax3, CDH19). Our study shows that many genes, possibly contributing to nerve pathology can be identified by this approach. Experiment Overall Design: Experimental design: in total 12 (two-color) arrays were run. All neuropathy samples were in duplicate (technical replicates). Two CCFDN and two HMSN1A patients were also analyzed as biological replicates. Three healthy subjects were included from which one was in duplicate. All samples (Cy3) were compared to a common reference pool (Cy5) which consisted of a mix of all samples.
2008-04-05 | E-GEOD-7423 | biostudies-arrayexpress
Project description:The regenerative capacity of peripheral nerves declines during aging, contributing to the development of neuropathies, limiting organism function. Changes in Schwann cells prompt failures in instructing maintenance and regeneration of aging nerves; altered inflammatory environment leading to a defective Schwann cell response, as an underlying mechanism of impaired nerve regeneration during aging. Chronic inflammation was detected in intact uninjured old nerves, characterized by increased macrophage infiltration and raised levels of monocyte chemoattractant protein 1 (MCP1) and CC chemokine ligand 11 (CCL11). Schwann cells in the old nerves appeared partially dedifferentiated, accompanied by an activated repair program independent of injury. Upon sciatic nerve injury, an initial delayed immune response was followed by a persistent hyperinflammatory state accompanied by a diminished repair process. As a contributing factor to nerve aging, we showed that CCL11 interfered with Schwann cell differentiation in vitro and in vivo. Our results indicate that increased infiltration of macrophages and inflammatory signals diminish regenerative capacity of aging nerves by altering Schwann cell behavior. The study identifies CCL11 as a promising target for anti‐inflammatory therapies aiming to improve nerve regeneration in old age.
2019-09-18 | GSE137504 | GEO
Project description:Hereditary Motor and Sensory Neuropathies (HMSN) are the most common inherited peripheral neuropathies and comprise a group of genetically heterogeneous diseases. We study the genetic defects causing three demyelinating disorders: HMSN1A, HMSN-LOM and congenital cateracts facial dysmophism neuropathy (CCFDN) syndrome, which are caused by mutations in PMP22, NDRG1 and CTDP1, respectively. The function and patho-mechanisms of these genes is still unknown. To identify effects downstream of the mutations, thereby possibly involved in the disease process, we used Serial expression of gene expression (SAGE) and microarray analysis. We analyzed human Schwann cell lines from three normal subjects, one HMSN-LOM patient, two HMSN-1A patients and two CCFDN patients and compared our data to a recent dataset of human Schwann cells (4 normal subjects passage 1 vs. 3, GDS1869/GSE4030 M.B. Bunge, 2006). We excluded genes that were not consistently regulated between biological and technical replicates and genes that were found to be influenced by passage number (p<0.05). Comparing expression profiles of demyelinating neuropathies with different mutations we identified: 1. expression signatures specific for each genotype. 2. Genes commonly (dys)regulated in all screened neuropathies. Interestingly, these include genes that play a role in reorganization of sodium channels in central and peripheral nerves (S100A10, CD90), or extracellular matrix remodeling (e.g. TGFBI, SERPINE1, THBS1). We also found high up-regulation of genes involved in Schwann cell lineage and in particular, genes that are associated with an immature or pre-myelinating Schwann cell phenotype (i.e. Sox2, Sox10, COL18A1, TFAP2A, Pax3, CDH19). Our study shows that many genes, possibly contributing to nerve pathology can be identified by this approach. Keywords: disease state analysis, genotype down-stream effects analysis
2008-03-01 | GSE7423 | GEO
Project description:Schwann cell (Büngner) repair cells play a critical role in orchestrating nerve repair after injury, but the reprogramming process that generates them is poorly understood. We present the first combined whole genome coding and non-coding RNA and CpG methylation study after nerve injury. We show that genes involved in epithelial to mesenchymal transition are enriched in repair cells and we identify long non-coding RNAs in Schwann cells. We demonstrate that the AP-1 transcription factor c-Jun regulates the expression of certain micro RNAs in repair cells, in particular miR-21 and miR-34. Surprisingly, changes in CpG methylation are limited in injury, unlike development, and restricted to specific locations, such as enhancer regions of novel Schwann cell specific genes, such as Nedd4l, and near to local enrichment of AP-1 motifs. These epigenetic changes significantly broaden our understanding of Schwann cell reprogramming in peripheral nervous system tissue repair. To identify epigenetic regulators underlying successful nerve regeneration we generated RNA-Seq, small-RNA-Seq and whole genome bisulfite sequencing libraries for uninjured nerve versus three and/or seven day post nerve transection sciatic nerves of adult C57BL/6J mice crush.
2017-08-30 | E-MTAB-5633 | biostudies-arrayexpress
Project description:After peripheral nerve injury, adult Schwann cells convert to progenitor cell-like repair Schwann cells, which are pivotal for nerve regeneration. We show that Schwann cell-specific deletion of TFEB/3 disrupts the transcriptomic reprogramming necessary for injury-induced repair Schwann cell generation in mice. The mutant mice fail to generate proliferating repair Schwann cells to populate the injured nerves. Distal Schwann cells fail to express injury-responsive genes and continue to maintain the expression of myelin-associated genes. TFEB/3 binding motifs are enriched in injury-induced enhancers, suggesting their role in repair gene activation. Autophagy-dependent myelin breakdown is not impaired in the mutant mice despite the known function of TFEB/3 as autophagy activators. However, the mutant mice exhibit defects in axon regeneration, target reinnervation, and functional recovery. Therefore, TFEB/3 play a critical role in orchestrating transcriptional changes essential for repair Schwann cell generation and function necessary for peripheral nerve regeneration.
2024-08-12 | GSE249114 | GEO
Project description:Fasting triggers diverse physiological adaptations including increases in circulating fatty acids and mitochondrial respiration to facilitate organismal survival. The mechanisms driving mitochondrial adaptations and respiratory sufficiency during fasting remain incompletely understood. Here we show that fasting or lipid availability stimulates mTORC2 activity. Activation of mTORC2 and phosphorylation of its downstream target NDRG1 at Ser336 sustains mitochondrial fission and respiratory sufficiency. Timelapse imaging shows that NDRG1, but not phosphorylation-deficient NDRG1Ser336Ala mutant, engages with mitochondria to facilitate fission in both control and Drp1-deficient cells, reflecting independency from Drp1. Using proteomics, an siRNA screen, and epistasis experiments, we show that mTORC2-phosphorylated NDRG1 cooperates with small GTPase Cdc42 and effectors and regulators of Cdc42 to orchestrate fission. Accordingly, RictorKO, NDRG1Ser336Ala mutants, and Cdc42-deficient cells each display mitochondrial phenotypes reminiscent of fission failure. During nutrient surplus, mTOR complexes perform anabolic functions; however, paradoxical reactivation of mTORC2 during fasting unexpectedly drives mitochondrial fission and respiration.
2023-04-27 | PXD041696 | Pride
Project description:The striking PNS regenerative response to injury rests on the plasticity of adult Schwann cells and their ability to transit between differentiation states, a highly unusual feature in mammals. Using mice with inactivation of Schwann cell c-Jun, we show that the injury response involves c-Jun dependent natural reprograming of differentiated cells to generate a distinct Schwann cell state specialized to promote regeneration. Transected distal stumps of c-Jun mutants show 172 disregulated genes, resulting in abnormal expression of growth factors, adhesion molecules and cytoskeletal changes that lead to neuronal death, inhibition of axon growth and striking failures of functional repair after injury. These observations provide a molecular basis for understanding Schwann cell plasticity and nerve regeneration. They offer conclusive support for the notion that Schwann cells control repair in the PNS, using dedicated transcriptional controls to generate a distinct repair cell, a transition that shows similarities to transdifferentiation seen in other systems. Total RNA was purified from a 10mm segment of the distal stump and uninjured contralateral nerve from c-Jun mutants and control mice 7 days after nerve cut. For each condition (injured/uninjured) and genotype (control/ knock-out) 2 independent samples (replicates) were generated from pooled nerves of 4/6 mice resulting in a total of 8 samples: CTRL.cut.R1, CTRL.cut.R2, CTRL.uncut.R1, CTRL.uncut.R2, KO.cut.R1, KO.cut.R2, KO.uncut.R1,KO.uncut.R2.
2012-06-13 | E-GEOD-38693 | biostudies-arrayexpress
Project description:Peripheral glial Schwann cells switch to a repair state after nerve injury, proliferate to supply lost cell population, migrate to form regeneration tracks, and generates a permissive microenvironment for nerve regeneration. Exploring essential regulators of the repair responses of Schwann cells may benefit the clinical treatment for peripheral nerve injury. In the present study, FOSL1 regulates Schwann cell phenotype modulation and provided a novel therapeutic approach to orchestrate the regeneration and functional recovery of injured peripheral nerves.
2022-10-02 | GSE214449 | 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:The striking PNS regenerative response to injury rests on the plasticity of adult Schwann cells and their ability to transit between differentiation states, a highly unusual feature in mammals. Using mice with inactivation of Schwann cell c-Jun, we show that the injury response involves c-Jun dependent natural reprograming of differentiated cells to generate a distinct Schwann cell state specialized to promote regeneration. Transected distal stumps of c-Jun mutants show 172 disregulated genes, resulting in abnormal expression of growth factors, adhesion molecules and cytoskeletal changes that lead to neuronal death, inhibition of axon growth and striking failures of functional repair after injury. These observations provide a molecular basis for understanding Schwann cell plasticity and nerve regeneration. They offer conclusive support for the notion that Schwann cells control repair in the PNS, using dedicated transcriptional controls to generate a distinct repair cell, a transition that shows similarities to transdifferentiation seen in other systems.
2012-06-14 | GSE38693 | GEO