Similar Datasets
Project description:Focal white matter lesions occur in most neurodegenerative disorders. Despite occurring early in disease, white matter lesions are considered either independent of, or secondary to, grey matter neuroinflammation, synapse loss and altered neuronal activity. Notably their functional impact on neuronal circuits has been understudied. To address this, we generated a focal white matter lesion in an anatomically well-defined circuit, in which white matter lesions occur in many neurodegenerative disorders. Here we show that focal white matter lesions evoke transient neuronal activity changes and microgliosis, with subsequent synapse loss and increased microglia engulfment in the grey matter, which is reversed if myelin regeneration completes. Grey matter microgliosis is often considered detrimental but we show that it is an integral part of the myelin regenerative process. When we prevent these transient changes in the grey matter, myelin regeneration is blocked in the white matter. Conversely, inducing myelin regeneration failure leads to chronic neuroinflammation in the grey matter, suggesting that myelin regeneration failure drives sustained grey matter microglial activation. This recapitulates the low-grade inflammation considered to be a dominant mechanism underlying neurodegeneration. Our findings reveal a form of regenerative plasticity coupling white matter integrity to grey matter function - a novel mechanism of neuroplasticity that may underlie multiple neurodegenerative conditions - and highlights the potential of targeting myelin regeneration to prevent chronic inflammation.
2026-02-05 | GSE311781 | GEO
Project description:Bulk RNAseq data of white matter tissue injury
| PRJNA1372041 | ENA
Project description:Increasing evidence indicates heterogeneity in functional and molecular properties of oligodendrocyte lineage cells both during development and under pathologic conditions. In multiple sclerosis, remyelination of grey matter lesions exceeds that in white matter. Here we used cells derived from grey matter versus white matter regions of surgically resected human brain tissue samples, to compare the capacities of human A2B5-positive progenitor cells and mature oligodendrocytes to ensheath synthetic nanofibers, and relate differences to the molecular profiles of these cells. For both cell types, the percentage of ensheathing cells was greater for grey matter versus white matter cells. For both grey matter and white matter samples, the percentage of cells ensheathing nanofibers was greater for A2B5-positive cells versus mature oligodendrocytes. Grey matter A2B5-positive cells were more susceptible than white matter A2B5-positive cells to injury induced by metabolic insults. Bulk RNA sequencing indicated that separation by cell type (A2B5-positive vs mature oligodendrocytes) is more significant than by region but segregation for each cell type by region is apparent. Molecular features of grey matter versus white matter derived A2B5-positive and mature oligodendrocytes were lower expression of mature oligodendrocyte genes and increased expression of early oligodendrocyte lineage genes. Genes and pathways with increased expression in grey matter derived cells with relevance for myelination included those related to responses to external environment, cell-cell communication, cell migration, and cell adhesion. Immune and cell death related genes were up-regulated in grey matter derived cells. We observed a significant number of up-regulated genes shared between the stress/injury and myelination processes, providing a basis for these features. In contrast to oligodendrocyte lineage cells, no functional or molecular heterogeneity was detected in microglia maintained in vitro, likely reflecting the plasticity of these cells ex vivo. The combined functional and molecular data indicate that grey matter human oligodendrocytes have increased intrinsic capacity to myelinate but also increased injury susceptibility, in part reflecting their being at a stage earlier in the oligodendrocyte lineage.
2024-11-08 | GSE281006 | GEO
Project description:Tissue progenitors maintain the integrity of organ systems through aging and stress. The brain’s white matter regions experience ischemic lesions and age-dependent degeneration. Brain white matter contains progenitors, oligodendrocyte precursor cells (OPCs), which can repair some insults. The response of OPCs to white matter ischemia and aging is not known. We characterized the response of OPCs to white matter stroke using OPC reporter mice, cell migration tracking, OPC specific RNA sequencing, and mechanistic studies in candidate biochemical pathways in the aged brain. White matter stroke induces initial proliferation of local OPCs but blocks differentiation, shunting a portion into astrocytes. Candidate signaling pathways for this differentiation block including novel interactions of inhibin and matrilin-2 and new roles of NgR1 ligands following white matter stroke. Stroke induces inhibin expression in astrocytes and downregulates OPC matrilin-2 that contributes into OPC differentiation block. Antagonism of NgR1 ligands promotes OPC differentiation by attenuating the OPC astrocytic transformation and enhances functional recovery from stroke in aged animals.
2019-11-15 | GSE53737 | GEO
Project description:Objective: We previously reported that white matter connexin43 (Cx43) may related to the severity of the multiple sclerosis (MS), whereas the role of gray matter Cx43 in demyelinating disease is unknown. It was considered MS lesions were only exist in white matter, but recent studies revealed that demyelinating lesions are also exist in the cerebral cortex. This fact suggest the possibility that gray matter is somewhat related to the pathophysiology of MS. In this study, we aimed to clarify the role of gray matter Cx43 in a mouse model of MS (experimental autoimmune encephalomyelitis [EAE]). Methods: We developed Cx43F/F;Glutamate aspartate transporter (GLAST)-CreER(T2)KI/+ mice as gray matter specific Cx43 conditional knock-out (Cx43cKO) mice. We induced MOG-EAE 10 days after tamoxifen injection, and analyze its clinical course and pathology. We used Cx43F/F mice as controls. Results: EAE was significantly milder in gray matter astrocyte-specific Cx43cKO mice from acute phase to chronic phase, as compared with control mice. Pathology demonstrated less demyelinating lesions and infiltrating cells. Infiltrating immune cells did not express Cx43 in the active demyelinating lesions of the lumbar cord in both groups. The expression level of Cx43 was similar between these two groups in the spleen and the inguinal lymph nodes. Interpretation: Acute KO of gray matter specific Cx43 before induction of EAE reduce its aggressiveness. This finding may suggest the possibility that gray matter Cx43 modify the MS pathophysiology.
2021-04-20 | GSE148931 | GEO
Project description:Objective: We previously reported that white matter connexin43 (Cx43) may related to the severity of the multiple sclerosis (MS), whereas the role of gray matter Cx43 in demyelinating disease is unknown. It was considered MS lesions were only exist in white matter, but recent studies revealed that demyelinating lesions are also exist in the cerebral cortex. This fact suggest the possibility that gray matter is somewhat related to the pathophysiology of MS. In this study, we aimed to clarify the role of gray matter Cx43 in a mouse model of MS (experimental autoimmune encephalomyelitis [EAE]). Methods: We developed Cx43F/F;Glutamate aspartate transporter (GLAST)-CreER(T2)KI/+ mice as gray matter specific Cx43 conditional knock-out (Cx43cKO) mice. We induced MOG-EAE 10 days after tamoxifen injection, and analyze its clinical course and pathology. We used Cx43F/F mice as controls. Results: EAE was significantly milder in gray matter astrocyte-specific Cx43cKO mice from acute phase to chronic phase, as compared with control mice. Pathology demonstrated less demyelinating lesions and infiltrating cells. Infiltrating immune cells did not express Cx43 in the active demyelinating lesions of the lumbar cord in both groups. The expression level of Cx43 was similar between these two groups in the spleen and the inguinal lymph nodes. Interpretation: Acute KO of gray matter specific Cx43 before induction of EAE reduce its aggressiveness. This finding may suggest the possibility that gray matter Cx43 modify the MS pathophysiology.
2021-04-20 | GSE148929 | GEO
Project description:Aging results in both grey and white matter degeneration, but the specific microglial responses are unknown. Using single-cell RNA sequencing from white and grey matter separately, we identified white matter associated microglia (WAM), which share parts of the disease-associated microglia (DAM) gene signature and are characterized by the activation of genes implicated in phagocytic activity and lipid metabolism. WAM depend on triggering receptor expressed on myeloid cells 2 (TREM2) signaling and are aging dependent. In the aged brain, WAM form independently of apolipoprotein E (APOE), which is in contrast to mouse models of Alzheimer’s disease, in which microglia with WAM gene signature are generated prematurely and in an APOE-dependent pathway similar to DAM. Within the white matter, microglia frequently cluster in nodules, where they are engaged in clearing degenerated myelin. Thus, WAM may represent a potentially protective response required to clear degenerated myelin accumulating during white matter aging and disease.
2021-02-18 | GSE166548 | GEO
Project description:Vanishing white matter (VWM) is a leukodystrophy that primarily manifests in young children. In this disease, the brain white matter is differentially affected in a predictable pattern with telencephalic brain areas being more severely affected, while others remain allegedly completely spared. Using high-resolution mass spectrometry-based proteomics, we investigated the proteome patterns of the severely affected white matter in the frontal lobe and normal appearing pons in VWM and control cases to identify molecular bases underlying regional vulnerability. By comparing VWM patients to controls, we identified disease-specific proteome patterns. We showed substantial pathogenic changes in both the frontal white matter and pons at the protein level. Side-by-side comparison of brain region-specific proteome patterns further revealed regional differences. We found that different cell types are affected in the VWM frontal white matter than in the pons. Gene ontology and pathway analyses identified involvement of region distinct biological processes, of which pathways implicated in cellular respiratory metabolism were overarching features. In the VWM frontal white matter, proteome changes were associated with decrease in glycolysis/gluconeogenesis and metabolism of various amino acids. By contrast, in the VWM pons white matter, we found a decrease in oxidative phosphorylation. Taken together, our data show that brain regions are affected in parallel in VWM, but to different degrees. We found region-specific involvement of different cell types and discovered that cellular respiratory metabolism is differently affected across white matter regions in VWM. These region-specific changes help explain regional vulnerability to pathology in VWM.
2023-06-28 | PXD040861 | Pride
Project description:White matter aging drives microglial diversity
2021-02-08 | GSE166304 | GEO
Project description:Using laser capture microscopy, white (WM) and grey matter (GM) demyelinated areas and normal appearing matter was collected from histologically verified leukocortical lesions from snap-frozen human post mortem tissuederived from Multiple Sclerosis patients. Our data shows large differences in gene expression in WM and GM demyelinated areas (compared to their respective normal appearing matter) even when the demyelinated areas are spatially connected such as in leukocortical lesions. Thus, we show that WM demyelinated areas and GM demyelinated areas are distinct entities with distinct pathology. Therefore findings observed in WM demyelinated areas cannot be generalized to GM demyelinated areas.
2022-01-02 | GSE149326 | GEO