Project description:Adult neural progenitor cells (aNPCs) are a potential autologous cell source for cell replacement in neurologic diseases such as Parkinsonâs disease or stroke or for cell-based gene therapy for neurometabolic diseases. Easy accessibility, long-term expandability and detailed characterization of NPC properties are important requisites for their future translational/clinical applications. aNPC can be isolated from different regions of the adult human brain including the accessible subcortical white matter (aNPCWM), but systematic studies comparing long-term expanded aNPCWM with aNPC from neurogenic brain regions to check for their NPC characteristics and performance are not available. Freshly isolated cells from subcortical white matter and hippocampus (aNPCHIP) expressed oligodendrocyte progenitor cell (OPC) markers such as A2B5, NG2 and OLIG2 in ~20% of cells but no neural stem cell (NSC) markers such CD133 (Prominin1), NESTIN, SOX2 or PAX6. The EGF receptor (EGFR) protein was expressed in 18% of aNPCWM and 7% of aNPCHIP, but only a small fraction of 1 cell out 694 cells from white matter and only 1 out of 1,331 hippocampal cells were able to generate neurospheres. Studies comparing subcortical aNPCWM with their hippocampal counterparts showed that both NPC types expressed mainly markers of glial origin such as NG2, A2B5 and OLIG2, and the NSC/NPC marker Nestin, but no pericyte markers. Both NPC types were able to produce fully mature neurons, astrocytes and oligodendrocytes in comparable amounts to fetal NSC. Whole transcriptome analyses finally confirmed the strong similarity of aNPCWM with aNPCHIP. Our data show that aNPCWM are multipotent NPC with long-term expandability capacity similar to NPC from hippocampus making them an easily accessible source for possible autologous NPC-based treatment strategies. Isolation and propagation of multipotent NPCs. Adult human hippocampal (hip) and subcortical white matter (wm) tissue was obtained from routine epilepsy surgery procedures following informed consent of the subjects. All procedures were in accordance with the Helsinki convention and approved by the Ethical Committee of the University of Dresden (No. 47032006). All subjects underwent high-resolution magnetic resonance imaging excluding tumors and were screened for the presence of infectious disease. In all cases the neuropathological examinations did not reveal evidences for tumor formation. Gene expression Single-channel oligonucleotide microarray analysis. For the gene expression microarray analysis we used the Affimetrix U133A chips containing 22.215 probe sets representing at least 12.905 individual genes. The whole procedure was performed following the manufacturerâs standard protocol (Affimetrix, Santa Clara, CA). For the data processing, normalization was calculated with the GCRMA (GC content corrected Robust Multi-array Analysis) algorithm. fNSC: Human fetal neural stem cells, 2 biological rep aNPChip: Human adult neural progenitor cells isolated from hippocampus, 3 biological rep aNPCwm: Human adult neural progenitor cells isolated from white matter, 2 biological rep
Project description:A hallmark of nervous system aging is a decline of white matter volume and function, but the underlying mechanisms leading to white matter pathology are unknown. Here, we found age-related alterations of oligodendrocytes with a reduction of total oligodendrocyte density in the aging murine white matter. Using single-cell RNA sequencing, we identify interferon-responsive oligodendrocytes, which localize in proximity of CD8+ T cells in the aging white matter. Absence of functional lymphocytes decreased oligodendrocyte reactivity and rescued oligodendrocyte loss, while T-cell checkpoint inhibition worsened the aging effect. In addition, we identified a subpopulation of immune cell dependent interferon-responsive microglia in the aging white matter, and co-culture experiments revealed that interferon- activated microglia triggered oligodendrocytes cell death. In summary, we provide evidence that T cells induced interferon-responsive oligodendrocytes and microglia are important modifiers of white matter aging.
Project description:The repair of white matter damage is of paramount importance for functional recovery after brain injuries.We report that interleukin-4 (IL-4) promotes oligodendrocyte regeneration and remyelination. IL-4 receptor expression was detected in a variety of glial cells after ischemic brain injury, including oligodendrocyte lineage cells. IL-4 deficiency in knockout mice resulted in greater deterioration of white matter over 14 days after stroke. Consistent with these findings, intranasal delivery of IL-4 nanoparticles after stroke improved white matter integrity and attenuated long-term sensorimotor and cognitive deficits in wild-type mice, as revealed by histological immunostaining, electron microscopy, diffusion tensor imaging, and electrophysiology. The selective effect of IL-4 on remyelination was verified in an ex vivo organotypic model of demyelination. By leveraging primary oligodendrocyte progenitor cells (OPCs), microglia-depleted mice, and conditional OPC-specific PPARγ knockout mice, we discovered a direct salutary effect of IL-4 on oligodendrocyte differentiation that was mediated by the PPARγ axis. Our findings reveal a new regenerative role of IL-4 in the CNS, which lies beyond its known immunoregulatory functions on microglia/macrophages or peripheral lymphocytes. Therefore, intranasal IL-4 delivery may represent a novel therapeutic strategy to improve white matter integrity in stroke and other brain injuries.
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.
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.
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.
Project description:Adult neural progenitor cells (aNPCs) are a potential autologous cell source for cell replacement in neurologic diseases such as Parkinson’s disease or stroke or for cell-based gene therapy for neurometabolic diseases. Easy accessibility, long-term expandability and detailed characterization of NPC properties are important requisites for their future translational/clinical applications. aNPC can be isolated from different regions of the adult human brain including the accessible subcortical white matter (aNPCWM), but systematic studies comparing long-term expanded aNPCWM with aNPC from neurogenic brain regions to check for their NPC characteristics and performance are not available. Freshly isolated cells from subcortical white matter and hippocampus (aNPCHIP) expressed oligodendrocyte progenitor cell (OPC) markers such as A2B5, NG2 and OLIG2 in ~20% of cells but no neural stem cell (NSC) markers such CD133 (Prominin1), NESTIN, SOX2 or PAX6. The EGF receptor (EGFR) protein was expressed in 18% of aNPCWM and 7% of aNPCHIP, but only a small fraction of 1 cell out 694 cells from white matter and only 1 out of 1,331 hippocampal cells were able to generate neurospheres. Studies comparing subcortical aNPCWM with their hippocampal counterparts showed that both NPC types expressed mainly markers of glial origin such as NG2, A2B5 and OLIG2, and the NSC/NPC marker Nestin, but no pericyte markers. Both NPC types were able to produce fully mature neurons, astrocytes and oligodendrocytes in comparable amounts to fetal NSC. Whole transcriptome analyses finally confirmed the strong similarity of aNPCWM with aNPCHIP. Our data show that aNPCWM are multipotent NPC with long-term expandability capacity similar to NPC from hippocampus making them an easily accessible source for possible autologous NPC-based treatment strategies. Isolation and propagation of multipotent NPCs. Adult human hippocampal (hip) and subcortical white matter (wm) tissue was obtained from routine epilepsy surgery procedures following informed consent of the subjects. All procedures were in accordance with the Helsinki convention and approved by the Ethical Committee of the University of Dresden (No. 47032006). All subjects underwent high-resolution magnetic resonance imaging excluding tumors and were screened for the presence of infectious disease. In all cases the neuropathological examinations did not reveal evidences for tumor formation. Gene expression Single-channel oligonucleotide microarray analysis. For the gene expression microarray analysis we used the Affimetrix U133A chips containing 22.215 probe sets representing at least 12.905 individual genes. The whole procedure was performed following the manufacturer’s standard protocol (Affimetrix, Santa Clara, CA). For the data processing, normalization was calculated with the GCRMA (GC content corrected Robust Multi-array Analysis) algorithm.
Project description:Chronic alcohol consumption can lead to alchohol-related brain damage (ARBD). Despite the well known acute effects of alcohol the mechanism responsible for chronic brain damage is largely unknown. Pathologically the major change is the loss of white matter while neuronal loss is mild and restricted to a few areas such as the prefrontal cortex. In order to improve our understanding of ARBD pathogenesis we used microarrays to explore the white matter transcriptome of alcoholics and controls. Our results suggest that hepatic encephalopathy, along with two confounders, gray matter contamination and low RNA quality, are major drivers of gene expression in ARBD. All three exceeded the effects of alcohol itself. In particular, low quality RNA samples were characterized by an upregulation of protein translation machinery while hepatic encephalopathy was associated with a downregulation of mitochondrial energy metabolism pathways. The findings in HE alcoholics are consistent with the metabolic acidosis seen in this condition. In contrast non-HE alcoholics had widespread but only subtle changes in gene expression in their white matter. The initial cohort was compromised of four alcoholics without hepatic encephalopathy (non-HE alcoholics), three alcoholics with HE (HE alcoholics) and three neurologically normal controls. For each indvidual frozen white matter was sampled in the superior frontal gyrus (prefrontal cortex) and the precentral gyrus (motor cortex). These two cortices experience either moderate (prefrontal cortex) or no neuronal loss (motor cortex) with alcohol-related brain damage. Each white matter sample was divided in two before RNA was extracted to give two 'biological' repeats and a total of 40 samples. Subsequently eight duplicates were removed due to their gray matter contamination or low RNA quality to leave a 32-sample cohort (23 alcoholic (including eight with HE ) and nine control samples.