Presenilin deficiency results in cellular cholesterol accumulation by impairment of protein glycosylation and NPC1 function.
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ABSTRACT:
PROVIDER: PRJNA926897 | ENA |
REPOSITORIES: ENA
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Project description:Presenilin (PS) proteins represent the catalytic subunits of γ-secretase, and play a critical role in the generation of the Amyloid β (Aβ) peptide and the pathogenesis of Alzheimer’s disease (AD). Indeed, mutations in presenilin 1 (PS1) or PS2 are a major cause of early onset familial Alzheimer’s disease (FAD). However, PS proteins also exert multiple functions beyond Aβ generation. In this study, we examine the individual roles of PS1 and PS2 in cellular cholesterol metabolism. Deletion of PS1 or PS2 in mouse models led to cholesterol accumulation in cerebral neurons. Cholesterol accumulation was also observed in lysosomes of embryonic fibroblasts from PS1-KO and PS2-KO mice, and associated with decreased expression of the Niemann-Pick type C1 (NPC1) protein involved in intracellular cholesterol transport at late endosome/lysosome. Mass spectrometry and complementary biochemical methods also revealed abnormal N-glycosylation of NPC1 and several other membrane proteins in PS1-KO and PS2-KO cells. Interestingly, pharmacological inhibition of N-glycosylation resulted in intracellular cholesterol accumulation prominently in lysosomes as well as decrease of NPC1 expression in wild-type MEFs, thereby resembling the changes in PS1-KO and PS2-KO MEFs. In turn, treatment of PS1-KO and PS2-KO MEFs with a chaperone inducer, Arimoclomol, attenuated decrease of NPC1 and rescued the lysosomal cholesterol accumulation. Additionally, the intracellular cholesterol accumulation in PS1-KO and PS2-KO MEFs was prevented by NPC1 overexpression. Collectively, these data indicate that PS/γ-secretase dysfunction results in an impairment of protein N-glycosylation, which eventually causes NPC1 decrease and intracellular cholesterol accumulation. 3'RNASeq of mouse embryonic fibroblasts with PS1- or PS2-deficiency compared with controls. Biological replicates
2024-05-26 | GSE223572 | GEO
Project description:Purkinje cells (PC) of the cerebellum degenerate in adult mice with mutations in the Niemann-Pick type C (NPC) disease 1 (Npc1) gene. We subjected BALB/c Npc1+/+ and Npc1-/- mouse cerebella from an early and a later time point of PC degeneration to a genome-wide microarray gene expression analysis. We found general underrepresentation of PC-specific transcripts, consistent with PC loss, and elevated markers of microglia activation at the later time point. Experiment Overall Design: 12 BALB/c Npc1 mice of the two ages P21 and P49 and the two genotypes Npc1+/+ and Npc1-/- were used, 3 replicates for each age and genotype. The animals were of the same breed and lived under identical housing conditions. All except one animal were female. The animals were not further treated, but only sacrificed at P21 or P49.
2008-06-14 | E-GEOD-5944 | biostudies-arrayexpress
Project description:Purkinje cells (PC) of the cerebellum degenerate in adult mice with mutations in the Niemann-Pick type C (NPC) disease 1 (Npc1) gene. We subjected BALB/c Npc1+/+ and Npc1-/- mouse cerebella from an early and a later time point of PC degeneration to a genome-wide microarray gene expression analysis. We found general underrepresentation of PC-specific transcripts, consistent with PC loss, and elevated markers of microglia activation at the later time point. Keywords: Niemann-Pick type C, Purkinje cell degeneration
2007-07-01 | GSE5944 | GEO
Project description:Cholesterol is required for oligodendrocyte maturation and CNS myelination. Here, we demonstrate an essential role for the intracellular cholesterol transporter NPC1 in these processes. NPC1 functions in late endosomes and lysosomes to efflux unesterified cholesterol, and its deficiency causes Niemann-Pick disease Type C, an autosomal recessive lysosomal disorder characterized by progressive neurodegeneration and early death. To identify cell types and pathways affected early in pathogenesis, we performed single nuclear RNA-seq on the forebrain of Npc1-/- mice at P16. This analysis uncovered striking transcriptional changes in the oligodendrocyte lineage during the period of developmental myelination, accompanied by diminished maturation of myelinating oligodendrocytes. Unexpectedly, we identified a significant upregulation of genes associated with neurogenesis and synapse formation in Npc1-/- oligodendrocyte lineage cells, reflecting diminished gene silencing by H3K27me3 and H3K9me3. Npc1-/- oligodendrocyte progenitor cells reproduced impaired maturation in vitro and this phenotype was rescued by treatment with GSK-J4, a small molecule inhibitor of H3K27 demethylases. This study sought to determine the genes being directly impacted by the epigenetic dysfunction at H3K27.
2023-05-31 | GSE219007 | GEO
Project description:Cholesterol is required for oligodendrocyte maturation and CNS myelination. Here, we demonstrate an essential role for the intracellular cholesterol transporter NPC1 in these processes. NPC1 functions in late endosomes and lysosomes to efflux unesterified cholesterol, and its deficiency causes Niemann-Pick disease Type C, an autosomal recessive lysosomal disorder characterized by progressive neurodegeneration and early death. To identify cell types and pathways affected early in pathogenesis, we performed single nuclear RNA-seq on the forebrain of Npc1-/- mice at P16. This analysis uncovered striking transcriptional changes in the oligodendrocyte lineage during the period of developmental myelination, accompanied by diminished maturation of myelinating oligodendrocytes. Unexpectedly, we identified a significant upregulation of genes associated with neurogenesis and synapse formation in Npc1-/- oligodendrocyte lineage cells, reflecting diminished gene silencing by H3K27me3 and H3K9me3.
2023-05-31 | GSE221609 | GEO
Project description:Niemann-Pick Type C disease is an autosomal recessive neurodegenerative disorder with abnormal lipid storage as the major cellular pathologic hallmark. Genetic analyses have identified mutations in NPC1 gene in the great majority of cases, while mutations in NPC2 account for the remainders. Yet, little is known regarding the cellular mechanisms responsible for NPC pathogenesis, especially for neurodegeneration, which is the usual cause of death. To identify critical steps that could account for the pathological manifestations of the disease in one of the most affected brain structures, we performed global gene expression analysis in the cerebellum from three-week old Npc1+/+ and Npc1-/- mice with two different microarray platforms (Agilent and Illumina). Our results provide novel molecular insight regarding the mechanisms of pathogenesis in NPC disease and reveal potential new therapeutic targets. We performed global gene expression analysis in the cerebellum from three-week old Npc1+/+ and Npc1-/- mice with two different microarray platforms (Agilent and Illumina). Differentially-expressed genes identified by both microarray platforms were then subjected to KEGG pathway analysis. Expression of genes in six pathways was significantly altered in Npc1-/- mice; functionally, these signaling pathways belong to the following three categories: 1) steroid and terpenoid biosynthesis, 2) immune response, and 3) cell adhesion/motility. In addition, the expression of several proteins involved in lipid transport was significantly altered in Npc1-/- mice.
2010-08-30 | E-GEOD-20450 | biostudies-arrayexpress
Project description:Cholesterol is required for oligodendrocyte maturation and CNS myelination. Here, we demonstrate an essential role for the intracellular cholesterol transporter NPC1 in these processes. NPC1 functions in late endosomes and lysosomes to efflux unesterified cholesterol, and its deficiency causes Niemann-Pick disease Type C, an autosomal recessive lysosomal disorder characterized by progressive neurodegeneration and early death. To identify cell types and pathways affected early in pathogenesis, we performed single nuclear RNA-seq on the forebrain of Npc1-/- mice at P16. This analysis uncovered striking transcriptional changes in the oligodendrocyte lineage during the period of developmental myelination, accompanied by diminished maturation of myelinating oligodendrocytes. Unexpectedly, we identified a significant upregulation of genes associated with neurogenesis and synapse formation in Npc1-/- oligodendrocyte lineage cells, reflecting diminished gene silencing by H3K27me3 and H3K9me3. Npc1-/- oligodendrocyte progenitor cells reproduced impaired maturation in vitro and this phenotype was rescued by treatment with GSK-J4, a small molecule inhibitor of H3K27 demethylases. This study sought to determine the genes being directly impacted by the epigenetic dysfunction at H3K27.
2023-05-31 | GSE221336 | GEO
Project description:Cholesterol import in mammalian cells is mediated by the LDL receptor pathway. Here, we perform a genome-wide CRISPR screen using an endogenous cholesterol reporter and identify >100 genes involved in LDL-cholesterol import. We characterise C18orf8 as a core subunit of the mammalian Mon1-Ccz1 guanidine exchange factor (GEF) for Rab7, required for complex stability and function. C18orf8-deficient cells lack Rab7 activation and show severe defects in late endosome morphology and endosomal LDL trafficking, resulting in cellular cholesterol deficiency. Unexpectedly, free cholesterol accumulates within swollen lysosomes, suggesting a critical defect in lysosomal cholesterol export. We find that active Rab7 interacts with the NPC1 cholesterol transporter and licenses lysosomal cholesterol export. This process is abolished in C18orf8-, Ccz1- and Mon1A/B-deficient cells and restored by a constitutively active Rab7. The trimeric Mon1-Ccz1-C18orf8 (MCC) GEF therefore plays a central role in cellular cholesterol homeostasis coordinating Rab7 activation, endosomal LDL trafficking and NPC1-dependent lysosomal cholesterol export.
2020-10-29 | PXD021444 | Pride
Project description:Niemann-Pick Type C (NPC) disease is a rare, genetic, lysosomal disorder with progressive neurodegeneration. Poor understanding of the pathophysiology and lack of blood-based diagnostic markers are major hurdles in the treatment and management of NPC and several additional neurological, lysosomal disorders. To identify disease severity correlates, we undertook whole genome expression profiling of sentinel organs, brain, liver, and spleen of Balb/c Npc1-/- mice (Npc1nih)relative to Npc1+/- at an asymptomatic stage, as well as early- and late-symptomatic stages. Unexpectedly, we found prominent up regulation of innate immunity genes with age-dependent change in their expression, in all three organs. We shortlisted a set of 12 secretory genes whose expression steadily increased with age in both brain and liver, as potential plasma correlates for the neurological disease. Ten were innate immune genes with eight ascribed to lysosomes. Several are known to be elevated in diseased organs of murine models of other lysosomal diseases including GaucherM-bM-^@M-^Ys disease, Sandhoff disease and MPSIIIB. We validated the top candidate lysozyme, in the plasma of Npc1-/- as well as Balb/c Npc1nmf164 mice (bearing a point mutation closer to human disease mutants) and show its reduction in response to an emerging therapeutic. We further established elevation of innate immunity in Npc1-/- mice through multiple functional assays including inhibition of bacterial infection as well as cellular analysis and immunohistochemistry. We used microarrays on the diseased organs, brain, liver and spleen of the Npc1-/- mice to unserstand the molecular changes occur during the progression of NPC diseases. From the data, we have identified 12 potential genes which can be potentially developed as blood-based biomarker. We have also discovered up regulation of innate iimunity genes in all three organs of Npc1-/- mice and functionally validated them in liver and spleen. Brain from 11 female Npc1M-bM-^HM-^R/M-bM-^HM-^R and 16 control female mice (Npc1+/+ and Npc1+/M-bM-^HM-^R) from 6 age groups (20-25, 37-40, 54-55, 59-62, 67-71 and 81-84 days) were surgically harvested. Liver and spleen from 6 Npc1-/- and 6 Npc1+/- female mice from three age group ( 20-25, 54-55 and 67-71 days) were surgically harvested. Organs were kept in RNA later and stored at -20 M-BM-0C until used. RNA was isolated and Affymetrix mouse 430 2.0 array hybridizations were performed by M-bM-^@M-^XUCLA Clinical Microarray CoreM-bM-^@M-^Y, UCLA, Los Angeles, CA, USA. Subsequent raw data were analyzed using DNA-Chip Analyzer (D-Chip) with the .CEL files obtained from AGCC. Data from Npc1-/- mice from all age groups were compared to control mice (Npc1+/- and/or Npc1-/- mice) from all age groups separately for brain, liver and spleen. 'Matrix Table1' corrsponds for brain, 'Matrix Table2' corresponds for liver and 'Matrix Table3' corresponds for spleen. Thresholds for selecting significant genes were set at a relative difference M-BM-31.5-fold, absolute difference M-BM-3100 signal intensity units and p<0.05. Genes that met all three criteria simultaneously were considered as significant change.
2012-12-27 | E-GEOD-39621 | biostudies-arrayexpress
Project description:We used microarrays to detail the global programme of gene expression underlying the disease progression in the mutant mice compared to their control littermates. We collected liver tissue from 1-, 3-, 5-, 7-, 9-, and 11-week-old Npc1+/+ and Npc1-/- mice (N=4), and some additional controls.
2012-07-11 | E-GEOD-33467 | biostudies-arrayexpress