GCase and LIMP2 Abnormalities in the Liver of Niemann Pick Type C Mice.
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ABSTRACT:
SUBMITTER: van der Lienden MJC
PROVIDER: S-EPMC7959463 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Primary skin fibroblasts from four Niemann-Pick type C patients homozygous for the I1061T mutation and four control individuals were cultured under identical conditions in DMEM containing 10% fetal bovine serum. Cells were harvested at 50-70% confluency. mRNA was isolated with the FastTrack 2.0 mRNA isolation kit according to the manufacturer's instructions (Invitrogen, Carlsbad, CA). A reference RNA comprised of 10 cell lines was used as the control for each hybridized sample (Stratagene, La Jolla, CA). Both sample and reference RNAs were amplified using the MessageAmp II aRNA amplification kit (Ambion, Austin, TX). Set of arrays that are part of repeated experiments Keywords: Biological Replicate
2007-08-15 | GSE8770 | GEO
Project description:Primary skin fibroblasts from four Niemann-Pick type C patients homozygous for the I1061T mutation and four control individuals were cultured under identical conditions in DMEM containing 10% fetal bovine serum. Cells were harvested at 50-70% confluency. mRNA was isolated with the FastTrack 2.0 mRNA isolation kit according to the manufacturer's instructions (Invitrogen, Carlsbad, CA). A reference RNA comprised of 10 cell lines was used as the control for each hybridized sample (Stratagene, La Jolla, CA). Both sample and reference RNAs were amplified using the MessageAmp II aRNA amplification kit (Ambion, Austin, TX). Set of arrays that are part of repeated experiments Biological Replicate Complex
2007-08-15 | E-GEOD-8770 | biostudies-arrayexpress
Project description:The enzyme glucocerebrosidase (GBA) hydrolyses glucosylceramide (GlcCer) in lysosomes. Markedly reduced GBA activity is associated with severe manifestations of Gaucher disease including neurological involvement. Mutations in the GBA gene have recently also been identified as major genetic risk factor for Parkinsonism. Disturbed metabolism of GlcCer may therefore play a role in neuropathology. Besides lysosomal GBA, cells also contain a non-lysosomal glucosylceramidase (GBA2). Given that the two β-glucosidases share substrates, we speculated that over-activity of GBA2 during severe GBA impairment might influence neuropathology. This hypothesis was studied in Niemann-Pick type C (Npc1-/-) mice showing secondary deficiency in GBA in various tissues. Here we report that GBA2 activity is indeed increased in the brain of Npc1-/- mice. We found that GBA2 is particularly abundant in Purkinje cells (PCs), one of the most affected neuronal populations in NPC disease. Inhibiting GBA2 in Npc1-/- mice with a brain-permeable low nanomolar inhibitor significantly improved motor coordination and extended lifespan in the absence of correction in cholesterol and ganglioside abnormalities. This trend was recapitulated, although not to full extent, by introducing a genetic loss of GBA2 in Npc1-/- mice. Our findings point to GBA2 activity as therapeutic target in NPC.
| S-EPMC4537125 | biostudies-literature
Project description:Loss of function of Niemann-Pick C1 (NPC1) leads to lysosomal free cholesterol storage, resulting in the neurodegenerative disease Niemann-Pick disease type C (NPC). Significant numbers of patients with NPC also suffer from liver disease. Currently, no treatments exist that alter patient outcome, and it is unknown if recovery from tissue damage can occur even if a treatment were found. Our laboratory developed a strategy to test whether mice can recover from NPC liver disease. We used antisense oligonucleotides to knock down hepatic expression of NPC1 in BALB/C mice for either 9 or 15 weeks. This recapitulated liver disease with hepatomegaly, cell death, and fibrosis. Then, antisense oligonucleotide treatment was halted for an additional 4, 9, or 15 weeks. We report that significant liver recovery occurred even when NPC1 protein expression only partially returned to normal. Several pathological phenotypes were alleviated, including hepatomegaly, cholesterol storage, and liver cell death. Histological examination revealed that foamy cell accumulation was relieved; however, liver fibrosis increased. Additionally, resolution of cholesterol storage and liver cell death took longer in mice with long-term knockdown. Finally, we found that transcription of cholesterol homeostatic genes was significantly disrupted during the recovery phase after long-term knockdown.
| S-EPMC2903820 | biostudies-literature
Project description:Background and aimsHepatic cholesterol deposition drives inflammation and fibrosis in non-alcoholic steatohepatitis (NASH). The Niemann-Pick type C2 (NPC2) protein plays an important role in regulating intracellular cholesterol trafficking and homeostasis. We hypothesized that intravenous NPC2 supplementation reduces cholesterol accumulation, hepatic inflammation and fibrogenesis in a nutritional NASH rat model.MethodsRats were fed a high-fat, high-cholesterol (HFHC) diet for four weeks resulting in moderately severe NASH. Animals were treated with intravenous NPC2 or placebo twice weekly for either the last two weeks or the entire four weeks. End-points were liver/body- and spleen/body weight ratios, histopathological NASH scores, fibrosis, serum liver enzymes, cholesterol, lipoproteins, cytokines, and quantitative polymerase chain reaction derived hepatic gene expression related to cholesterol metabolism, inflammation, and fibrosis.ResultsHFHC rats developed hepatomegaly, non-fibrotic NASH histopathology, elevated liver enzymes, serum cholesterol, and pro-inflammatory cytokines. Their sterol regulatory element binding factor 2 (SREBF2) and low-density lipoprotein receptor (LDL-R) mRNAs were down-regulated compared with rats on standard chow. NPC2 did not improve liver weight, histopathology, levels of serum liver enzymes or pro-inflammatory tumor necrosis factor-α (TNFα), Interleukin (IL)-6, or IL-1β in HFHC rats. Two weeks of NPC2 treatment lowered hepatic TNFα and COL1A1 mRNA expression. However, this effect was ultimately reversed following additional two weeks of treatment. Four weeks NPC2 treatment of rats raised ATP-binding cassette A1 (ABCA1) and low-density lipoprotein receptor (LDLR) mRNAs in the liver, concurrent with a strong tendency towards higher serum high-density lipoprotein (HDL). Furthermore, the peroxisome proliferator activated receptor-ɣ (PPARG) gene expression was reduced.ConclusionsNPC2 proved inefficient at modifying robust hepatic NASH end-points in a HFHC NASH model. Nonetheless, our data suggest that hepatic ABCA1 expression and reverse cholesterol transport were upregulated by NPC2 treatment, thus presenting putative therapeutic effects in diseases associated with deregulated lipid metabolism.
| S-EPMC5844539 | biostudies-literature
Project description:Niemann-Pick C (NPC) disease is due to loss of NPC1 or NPC2 protein function that is required for unesterified cholesterol transport from the endosomal/lysosomal compartment. Though lung involvement is a recognized characteristic of Niemann-Pick type C disease, the pathological features are not well understood. We investigated components of the surfactant system in both NPC1 mutant mice and felines and in NPC2 mutant mice near the end of their expected life span. Histological analysis of the NPC mutant mice demonstrated thickened septae and foamy macrophages/leukocytes. At the level of electron microscopy, NPC1-mutant type II cells had uncharacteristically larger lamellar bodies (LB, mean area 2-fold larger), while NPC2-mutant cells had predominantly smaller lamellar bodies (mean area 50% of normal) than wild type. Bronchoalveolar lavage from NPC1 and NPC2 mutant mice had an approx. 4-fold and 2.5-fold enrichment in phospholipid, respectively, and an approx. 9-fold and 35-fold enrichment in cholesterol, consistent with alveolar lipidosis. Phospholipid and cholesterol also were elevated in type II cell LBs and lung tissue while phospholipid degradation was reduced. Enrichment of surfactant protein-A in the lung and surfactant of the mutant mice was found. Immunocytochemical results showed that cholesterol accumulated in the LBs of the type II cells isolated from the affected mice. Alveolar macrophages from the NPC1 and NPC2 mutant mice were enlarged compared to those from wild type mice and were enriched in phospholipid and cholesterol. Pulmonary features of NPC1 mutant felines reflected the disease described in NPC1 mutant mice. Thus, with the exception of lamellar body size, the lung phenotype seen in the NPC1 and NPC2 mutant mice were similar. The lack of NPC1 and NPC2 proteins resulted in a disruption of the type II cell surfactant system contributing to pulmonary abnormalities.
| S-EPMC3699545 | biostudies-literature
Project description:NPC (Niemann-Pick type C) disease is a progressive neurological disorder characterized by defects in intracellular cholesterol trafficking, accumulation of cholesterol in the endosomal system and impaired cholesterol homoeostasis. Although these alterations appear to occur in all NPC1-deficient cell types, the consequences are most profound in the nervous system. Since glial cells are important mediators of brain cholesterol homoeostasis, we proposed that defective generation and/or function of lipoproteins released by glia might contribute to the neurological abnormalities associated with NPC disease. We found that, as in other cell types, Npc1-/- glia accumulate cholesterol intracellularly. We hypothesized that this sequestration of cholesterol in glia might restrict the availability of cholesterol for lipoprotein production. Cerebellar astroglia were cultured from a murine model of NPC disease to compare the lipoproteins generated by these cells and wild-type glia. The experiments demonstrate that the amount of cholesterol in glia-conditioned medium is not reduced by NPC1 deficiency. Similarly, cholesterol efflux to apo (apolipoprotein) A1 or glial expression of the transporter ATP-binding-cassette transporter A1 was not decreased by NPC1 deficiency. In addition, the ratio of apo E:cholesterol and the density distribution of lipoproteins in Npc1-/- and Npc1+/+ glia-conditioned medium are indistinguishable. Importantly, in a functional assay, apo E-containing lipoproteins generated by Npc1-/- and Npc1+/+ glia each stimulate axonal elongation of neurons by approx. 35%. On the basis of these observations, we speculate that the neuropathology characteristic of NPC disease can quite probably be ascribed to impaired processes within neurons in the brain rather than defective lipoprotein production by astroglia.
| S-EPMC1135009 | biostudies-other
Project description:BACKGROUND: Neurotrophins and their receptors regulate several aspects of the developing and mature nervous system, including neuronal morphology and survival. Neurotrophin receptors are active in signaling endosomes, which are organelles that propagate neurotrophin signaling along neuronal processes. Defects in the Npc1 gene are associated with the accumulation of cholesterol and lipids in late endosomes and lysosomes, leading to neurodegeneration and Niemann-Pick type C (NPC) disease. The aim of this work was to assess whether the endosomal and lysosomal alterations observed in NPC disease disrupt neurotrophin signaling. As models, we used i) NPC1-deficient mice to evaluate the central cholinergic septo-hippocampal pathway and its response to nerve growth factor (NGF) after axotomy and ii) PC12 cells treated with U18666A, a pharmacological cellular model of NPC, stimulated with NGF. RESULTS: NPC1-deficient cholinergic cells respond to NGF after axotomy and exhibit increased levels of choline acetyl transferase (ChAT), whose gene is under the control of NGF signaling, compared to wild type cholinergic neurons. This finding was correlated with increased ChAT and phosphorylated Akt in basal forebrain homogenates. In addition, we found that cholinergic neurons from NPC1-deficient mice had disrupted neuronal morphology, suggesting early signs of neurodegeneration. Consistently, PC12 cells treated with U18666A presented a clear NPC cellular phenotype with a prominent endocytic dysfunction that includes an increased size of TrkA-containing endosomes and reduced recycling of the receptor. This result correlates with increased sensitivity to NGF, and, in particular, with up-regulation of the Akt and PLC-? signaling pathways, increased neurite extension, increased phosphorylation of tau protein and cell death when PC12 cells are differentiated and treated with U18666A. CONCLUSIONS: Our results suggest that the NPC cellular phenotype causes neuronal dysfunction through the abnormal up-regulation of survival pathways, which causes the perturbation of signaling cascades and anomalous phosphorylation of the cytoskeleton.
| S-EPMC3395862 | biostudies-other
Project description:OBJECTIVES:The aim of this study was to comprehensively evaluate the auditory phenotype in Niemann-Pick disease, type C1 (NPC1), to understand better the natural history of this complex, heterogeneous disorder, and to define further the baseline auditory deficits associated with NPC1 so that use of potentially ototoxic interventions (e.g., 2-hydroxypropyl-ß-cyclodextrin) may be more appropriately monitored and understood. DESIGN:Fifty patients with NPC1 ranging in age from 4 months to 21 years (mean = 9.3 years) enrolled in a natural history/observational study at the National Institutes of Health. The auditory test battery included, when possible, immittance audiometry, pure-tone and speech audiometry, otoacoustic emission testing, and a neurotologic auditory brainstem response study. Longitudinal data were collected on a subset of patients. RESULTS:Over half of the cohort exhibited hearing loss involving the high frequencies ranging from a slight to moderate degree, and 74% of patients presented with clinically significant hearing loss involving the frequencies most important to speech understanding (0.5, 1, 2, 4 kHz). Despite the heterogeneity of the sample, results among patients were sufficiently consistent to implicate retrocochlear dysfunction in the majority (66%) of individuals, with (22%) or without (44%) accompanying cochlear involvement. Some patients (10%) presented with a profile for auditory neuropathy spectrum disorder. The combination of cross-sectional and longitudinal data indicates these patients are at risk for a progressive decline in auditory function. CONCLUSIONS:This is the largest cohort of patients with NPC1 evaluated comprehensively for auditory dysfunction, and results implicate the pathological processes of NPC1 in the manifestation of hearing loss. Patients with NPC1 should be monitored audiologically throughout their lives, beginning at the time of diagnosis. Clinicians and researchers should be aware of this historically overlooked aspect of the phenotype.
| S-EPMC3895917 | biostudies-literature
Project description:Niemann-Pick type C disease (NPCD) is a lysosomal storage disorder caused by mutations in the NPC1 gene. The most affected tissues are the central nervous system and liver, and while significant efforts have been made to understand its neurological component, the pathophysiology of the liver damage remains unclear. In this study, hepatocytes derived from wild type and Npc1-/- mice were analyzed by mass spectrometry (MS)-based proteomics in conjunction with bioinformatic analysis. We identified 3832 proteins: 416 proteins had a p-value smaller than 0.05, of which 37% (n = 155) were considered differentially expressed proteins (DEPs), 149 of them were considered upregulated, and 6 were considered downregulated. We focused the analysis on pathways related to NPC pathogenic mechanisms, finding that the most significant changes in expression levels occur in proteins that function in the pathways of liver damage, lipid metabolism, and inflammation. Moreover, in the group of DEPs, 30% (n = 47) were identified as lysosomal proteins and 7% (n = 10) were identified as mitochondrial proteins. Importantly, we found that lysosomal DEPs, including CTSB/D/Z, LIPA, DPP7 and GLMP, and mitocondrial DEPs, AKR1B10, and VAT1 had been connected with liver fibrosis, damage, and steatosis in previous studies, validiting our dataset. Our study found potential therapeutic targets for the treatment of liver damage in NPCD.
| S-EPMC8392304 | biostudies-literature