T cell mediated microglia activation triggers myelin pathology in a model of amyloidosis [MERFISH]
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus synthetic construct
PROVIDER: GSE243120 | GEO | 2024/05/14
REPOSITORIES: GEO
Similar Datasets
Project description:Age-related myelin damage induces inflammatory responses, yet its involvement in Alzheimer’s disease (AD) remains uncertain, despite age being a major risk factor. Using a mouse model of AD, we found that amyloidosis itself triggers age-related oligodendrocyte and myelin damage. Mechanistically, CD8+ T cells promote the progressive accumulation of abnormally interferon-activated microglia that display myelin-damaging activity. Thus, immune responses against myelinating oligodendrocytes may contribute to neurodegenerative diseases with amyloidosis.
2024-05-10 | GSE243018 | GEO
Project description:Axon degeneration and neurological dysfunction in myelin diseases is often attributed to loss of myelin. Perturbed myelinating glia can instigate chronic neuroinflammation and contribute to demyelination and axonal damage. We have previously shown in mice that distinct defects in the proteolipid protein 1 gene result in axonal damage which is largely driven by cytotoxic T cells targeting myelinating oligodendrocytes. Here we show in these mutants that persistent ensheathment with perturbed myelin poses a risk for axon degeneration, neuron loss, and behavioral decline. We demonstrate that CD8+ T cell-driven axonal damage is less likely to progress towards degeneration when axons are efficiently demyelinated by activated microglia. Mechanistically, we show that cytotoxic T cell effector molecules induce aberrant cytoskeletal plasticity within myelinating glial processes and constriction of axons at paranodal domains. Our study identifies detrimental axon-glia interactions which promote neurodegeneration and possible therapeutic targets for disorders associated with myelin defects and neuroinflammation.
2023-09-29 | GSE224032 | GEO
Project description:Exercise interventions are beneficial for reducing the risk of age-related diseases, including amyloidosis, but the underlying molecular links remain unelucidated. Here, we investigated the protective role of interval exercise training in a mouse model of age-related systemic apolipoprotein A-II amyloidosis (AApoAII) and elucidated potential mechanisms. Mice subjected to sixteen weeks of exercise improved whole-body physiologic functions and exhibited substantial inhibition of amyloidosis, particularly in the liver and spleen. Exercise activated the hepatic p38 mitogen-activated protein kinase (p38 MAPK) signaling pathway and the downstream transcription factor tumor suppressor p53. This activation resulted in elevated expression and phosphorylation of heat shock protein beta-1 (HSPB1), a chaperone that defends against protein aggregation. In the amyloidosis-induced mice, the hepatic p38 MAPK-related adaptive responses were additively enhanced by exercise. We observed that with exercise, greatly increased amounts of phosphorylated HSPB1 accumulated at amyloid deposition areas, which we suspect to inhibit amyloid fibril formation. Collectively, our findings conclude exercise-activated, specific chaperone prevention of amyloidosis, and suggest that exercise may amplify intracellular stress-related protective adaptation pathways against age-associated disorders such as amyloidosis.
2022-03-04 | GSE192521 | GEO
Project description:Schwann cell remyelination defects impair functional restoration after nerve damage, contributing to peripheral neuropathies. The mechanisms that mediate remyelination block remain elusive. Upon small-molecule epigenetic screening, we identified HDAC3, a histone-modifying enzyme, as a potent inhibitor of peripheral myelinogenesis. Inhibition of HDAC3 markedly enhances myelin growth and regeneration, and improves functional recovery after peripheral nerve injury. HDAC3 antagonizes myelinogenic neuregulin/PI3K/AKT signaling axis. Moreover, genome-wide profiling analyses reveal that HDAC3 represses pro-myelinating programs through epigenetic silencing, while coordinating with p300 histone acetyltransferase to activate myelination-inhibitory programs that include HIPPO signaling effector TEAD4 to inhibit myelin growth. Schwann-cell-specific deletion of either Hdac3 or Tead4 results in a profound increase in myelin thickness in sciatic nerves. Thus, our findings identify the HDAC3-TEAD4 network as a dual-function switch of cell-intrinsic inhibitory machinery that counters myelinogenic signals and maintains peripheral myelin homeostasis, highlighting the therapeutic potential of transient HDAC3 inhibition for improving peripheral myelin repair.
2018-02-11 | GSE93159 | GEO
Project description:Schwann cell remyelination defects impair functional restoration after nerve damage, contributing to peripheral neuropathies. The mechanisms that mediate remyelination block remain elusive. Upon small-molecule epigenetic screening, we identified HDAC3, a histone-modifying enzyme, as a potent inhibitor of peripheral myelinogenesis. Inhibition of HDAC3 markedly enhances myelin growth and regeneration, and improves functional recovery after peripheral nerve injury. HDAC3 antagonizes myelinogenic neuregulin/PI3K/AKT signaling axis. Moreover, genome-wide profiling analyses reveal that HDAC3 represses pro-myelinating programs through epigenetic silencing, while coordinating with p300 histone acetyltransferase to activate myelination-inhibitory programs that include HIPPO signaling effector TEAD4 to inhibit myelin growth. Schwann-cell-specific deletion of either Hdac3 or Tead4 results in a profound increase in myelin thickness in sciatic nerves. Thus, our findings identify the HDAC3-TEAD4 network as a dual-function switch of cell-intrinsic inhibitory machinery that counters myelinogenic signals and maintains peripheral myelin homeostasis, highlighting the therapeutic potential of transient HDAC3 inhibition for improving peripheral myelin repair.
2018-02-11 | GSE93160 | GEO
Project description:Myelin is required for the function of neuronal axons in the central nervous system, yet the mechanisms supporting myelin health are unclear. Although central nervous system macrophages have been implicated, it is unknown which macrophage populations are involved and which aspects of myelin health they influence. Here, we show that resident microglia are critical for the maintenance of myelin health in adulthood in both mouse and human. We demonstrate that whereas microglia are dispensable for developmental myelin ensheathment, they are required for subsequent regulation of myelin growth and associated cognitive function, and for the preservation of myelin integrity by preventing its degeneration. We discovered that loss of myelin health in the absence of microglia is underpinned by the appearance of a myelinating oligodendrocyte subpopulation with altered lipid metabolism, regulated by a disruption of the TGFβ1-TGFβR1 axis. Our findings highlight microglia as promising therapeutic targets for conditions where myelin growth and integrity are dysregulated, such as in ageing and neurodegenerative disease.
2022-10-16 | GSE215440 | GEO
Project description:1. Aging is a major risk factor for the development of nervous system functional decline, even in the absence of diseases or trauma. The axon–myelin units and synaptic terminals are some of the neural structures most vulnerable to aging-related deterioration, but the underlying mechanisms are poorly understood. In the peripheral nervous system, macrophages—important representatives of the innate immune system—are prominent drivers of structural and functional decline of myelinated fibers and motor endplates during aging. Similarly, in the aging central nervous system (CNS), microglial cells promote damage of myelinated axons and synapses. Here we examine the role of cytotoxic CD8+ T lymphocytes, a type of adaptive immune cells previously identified as amplifiers of axonal perturbation in various models of genetically mediated CNS diseases but understudied in the aging CNS. We show that accumulation of CD8+ T cells drives axon degeneration in the normal aging mouse CNS and contributes to age-related cognitive and motor decline. We characterize CD8+ T-cell population heterogeneity in the adult and aged mouse brain by single-cell transcriptomics and identify aging-related changes. Mechanistically, we provide evidence that CD8+ T cells drive axon degeneration in a T-cell receptor- and granzyme B-dependent manner. Cytotoxic neural damage is further aggravated by systemic inflammation in aged but not adult mice. We also find increased densities of T cells in white matter autopsy material from older humans. Our results suggest that targeting CD8+ CNS-associated T cells in older adults might mitigate aging-related decline of brain structure and function. 2. Myelin defects lead to neurological dysfunction in various diseases and in normal aging. Chronic neuroinflammation often contributes to axon-myelin damage in these conditions and can be initiated and/or sustained by perturbed myelinating glia. We have previously shown that distinct mutations in the PLP1 gene result in neurodegeneration that is largely driven by adaptive immune cells. Here we characterize CD8+ CNS-associated T cells in these myelin mutants using single-cell transcriptomics and identify population heterogeneity and disease-associated changes. We demonstrate that early sphingosine-1-phosphate receptor modulation attenuates the recruitment of T cells and neural damage, while later targeting of CNS-associated T cell populations is inefficient and has no effect on neurodegeneration. Applying bone marrow chimerism and utilizing random X chromosome inactivation, we provide evidence that axonal damage is driven by cytotoxic, antigen specific CD8+ T cells that target mutant oligodendrocyte myelin. These findings offer insights into neural-immune interactions and are of translational relevance for neurological conditions associated with myelin defects and neuroinflammation.
2021-02-08 | GSE138891 | GEO
Project description:Chemokine-like factor-like MARVEL-transmembrane domain containing protein 5 (CMTM5) is a tetraspan-transmembrane protein highly enriched in oligodendrocytes and central nervous system (CNS) myelin. We analyzed the proteome of myelin biochemically purified from mouse brains upon genetic disruption of the Cmtm5-gene specifically in myelinating cells. An ion mobility-enhanced version of data-independent acquisition (DIA) workflow with alternating low and elevated energy (referred to as UDMSE) was used to compare protein abundance in Cmtm5 cKO and CTRL samples by label-free quantification. Specifically, dynamic range enhancement (DRE)-UDMSE was applied as a dedicated data acquisition mode recently introduced for routine differential myelin proteome profiling. We found that Cmtm5 cKO mice displayed a largely similar myelin proteome composition as control mice and, together with other data such as electron micrographs, concluded that CMTM5 is not essential for myelin biogenesis and composition. However, oligodendroglial Cmtm5-deficiency causes an early-onset progressive axonopathy, presumably following a Wallerian-like pathomechanism. These results indicate that CMTM5 is involved in the function of oligodendrocytes to maintain axonal integrity rather than myelin biogenesis.
2022-04-04 | PXD029443 | Pride
Project description:Rapid nerve conduction in the CNS is facilitated by the insulation of axons with myelin, a specialized oligodendroglial compartment distant from the cell body. Myelin is turned over and adapted throughout life; however, the molecular and cellular basis of myelin dynamics is not well understood. Hypothesizing that only a fraction of all myelin-related mRNAs has been identified so far, we subjected myelin biochemically purified from mouse brains at various ages to RNA sequencing. We find a surprisingly large pool of transcripts abundant and/or enriched in myelin. Furthermore, a comprehensive analysis showed that the myelin transcriptome is closely related to the myelin proteome but clearly distinct from the transcriptomes of oligodendrocytes and brain tissues, suggesting that the incorporation of mRNAs into the myelin compartment is highly selective. The mRNA-pool in myelin displays maturation-dependent dynamic changes of composition, abundance, and functional associations; however ageing-dependent changes after 6 months of age were minor. We suggest that this transcript pool provides a basis for the local modulation of myelin turnover and adaptation, i.e. in the individual internode. A light-weight membrane fraction enriched for myelin was purified from mouse brains as described previously (Jahn et al., Neuromethods, 2013). For RNA-Seq, RNA was isolated from myelin of mice from indicated ages.
2016-06-24 | E-GEOD-78151 | biostudies-arrayexpress
Project description:Aging of the peripheral nervous system (PNS) is associated with structural and functional changes that lead to a reduction in regenerative capacity and the development of age-related peripheral neuropathy. Myelin is a central component in maintaining physiological peripheral nerve function, and differences in myelin maintenance, degradation, formation and clearance have been suggested to contribute to age-related PNS changes. In addition, recent proteomic studies have elucidated the complex composition of the total myelin proteome in health and its changes in neuropathy models. However, changes in the myelin proteome of peripheral nerves during ageing have not been investigated. Hence, the aim of this proteomics experiment was to define proteome changes in isolated myelin fractions during ageing, by investigating myelin proteome profiles from young (nerves from 2-3 month old mice) and old (nerves from 18 months old mice) nerves.
2023-10-19 | PXD040719 | Pride