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Niemann-Pick disease type C (NPC) is characterized by the accumulation of cholesterol and sphingolipids in the late endosomal/lysosomal compartment. The mechanism by which the concentration of sphingolipids such as glucosylceramide is increased in this disease is poorly understood. We have found that, in NPC fibroblasts, the cholesterol storage affects the stability of glucosylceramidase (GCase), decreasing its mass and activity; a reduction of cholesterol raises the level of GCase to nearly normal values. GCase is activated and stabilized by saposin C (Sap C) and anionic phospholipids. Here we show by immunofluorescence microscopy that in normal fibroblasts, GCase, Sap C, and lysobisphosphatidic acid (LBPA), the most abundant anionic phospholipid in the endolysosomal system, reside in the same intracellular vesicular structures. In contrast, the colocalization of GCase, Sap C, and LBPA is markedly impaired in NPC fibroblasts but can be re-established by cholesterol depletion. These data show for the first time that the level of cholesterol modulates the interaction of GCase with its protein and lipid activators, namely Sap C and LBPA, regulating the GCase activity and stability.
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http://dx.doi.org/10.1074/jbc.M313517200 | DOI Listing |
PLoS One
September 2025
Department of Biology, Providence College, Providence, Rhode Island, United States of America.
In Npc1 deficient mice, postnatal developmental alterations in cerebellar microglia and Purkinje cells (PCs) are followed by early-onset neurodegeneration. Even in the absence of PC loss, microglia in Npc1nmf164 mice display hallmark features of activation during early postnatal development, including increased proliferation, enhanced phagocytic activity, and morphological changes indicative of an activated state. In this study, we investigated whether mammalian target of rapamycin complex 1 (mTORC1) drives postnatal activation of cerebellar microglia in Npc1nmf164 mice.
View Article and Find Full Text PDFInt J Dev Neurosci
October 2025
Department of Inherited Metabolic Disorders, Dokuz Eylul University Faculty of Medicine, Izmir, Turkey.
Niemann-Pick disease type C (NPC) is a lysosomal storage disorder characterized by progressive neurological deterioration. Although there is no curative treatment, early initiation of miglustat, prior to significant neurological decline, may slow disease progression. This case report describes a patient whose initial symptoms emerged around age 9 and who was diagnosed with NPC at age 14 following gradual neurological decline.
View Article and Find Full Text PDFFront Genet
August 2025
College of Laboratory Medicine, Hunan University of Medicine, Huaihua, China.
Niemann-Pick type C1 protein (NPC1), a key regulator of intracellular cholesterol transport and a transmembrane protein, has been implicated in carcinogenesis, particularly in hepatocellular carcinoma (HCC). Despite the noted association, the specific role of NPC1 in HCC remains underexplored. In this study, we conducted a comprehensive analysis of NPC1 expression across diverse gene expression databases to elucidate its prognostic significance and functional interactions.
View Article and Find Full Text PDFStem Cell Res Ther
August 2025
Stem Cell and Biotherapy Technology Research Center of Henan, School of Life Science and Technology, Xinxiang Medical University, Xinxiang, 453003, Henan, China.
Background: Niemann-Pick disease type C1 (NPC1) is caused by NPC1 gene mutations, resulting in Purkinje cell degeneration and death, glial cell activation, and progressive neurodegeneration. Menstrual blood-derived endometrial stem cells (MenSCs) have been explored as a promising tool for treating neurodegenerative diseases due to their wide range of sources, non-invasive nature, and regular collection methods.
Objectives: This study aims to investigate whether MenSCs can improve neuroinflammation and apoptosis in NPC1 mutant cell (Npc1 BV2 cell line) and mice (Npc1 mice), and explore their underlying mechanisms.
Genes (Basel)
July 2025
Tecnologico de Monterrey, Escuela de Medicina y Ciencias de la Salud, Campus Guadalajara, Zapopan 45201, Mexico.
Background/objectives: Niemann-Pick disease Type C (NPC) represents an autosomal recessive disorder with an incidence rate of 1 in 100,000 live births that belongs to the lysosomal storage diseases (LSDs). NPC is characterized by the abnormal accumulation of unesterified cholesterol, in addition to being an autosomal recessive inherited pathology, which belongs to LSDs. It occurs in 95% of cases due to mutations in the NPC1 gene, while 5% of cases are due to mutations in the NPC2 gene.
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