Project description:label-free quantification using 11 week mouse tissue lysates from non fractionated cerebellum and cerebral cortex of wild type and NPC1 null mice.
Project description:1) AJS-ESI source comparison of 2, 10 and 20ug of HeLa digest
2) Label-free analysis of 11-week NPC1 null mice and control for unfractionated cerebellum and cerebral cortex
3) Label-free analysis of 11-week NPC1 null mice and control for fractionated cerebellum
Project description:Macrophage inflammatory protein 1alpha/CCL3 protein is a known pro-inflammatory cytokine that can mediate chemotaxis of monocytes and promote cell degranulation. Ccl3 gene expression is elevated in the CNS and visceral tissue of many lysosomal storage disorders. The deletion of Ccl3 in a mouse model of Sandhoff disease was reported to result in reduced monocyte-associated pathology in the brain, delayed neurodegeneration, and prolonged health. However, deletion of Ccl3 in a mouse model of Niemann-Pick C disease was dentrimental or neutral instead of beneficial. Prevention of neuronal loss was instead mediated by providing NPC1 to neurons. We used microarrays to detail the global change in gene expression of the cerebellum in Niemann-Pick C disease animals, Niemann-Pick C disease animals with Ccl3 gene deletion, and Niemann-Pick C disease animals with Purkinje neuron-specific NPC1-YFP rescue. To identify the top ~50 genes elevated in NPC disease Npc1-/- (NPC) and Npc1+/- (WT) mice were compared at age P50; To profile changes in gene expression as a result of Ccl3 gene deletion Ccl3-/-;Npc1-/- mice were compared against Npc1-/- mice across various ages; To profile changes in gene expression as a result of Purkinje neuron-sepcific NPC1 rescue P;N;Npc1-/- mice were compared against Npc1-/- mice across various ages.
Project description:Macrophage inflammatory protein 1alpha/CCL3 protein is a known pro-inflammatory cytokine that can mediate chemotaxis of monocytes and promote cell degranulation. Ccl3 gene expression is elevated in the CNS and visceral tissue of many lysosomal storage disorders. The deletion of Ccl3 in a mouse model of Sandhoff disease was reported to result in reduced monocyte-associated pathology in the brain, delayed neurodegeneration, and prolonged health. However, deletion of Ccl3 in a mouse model of Niemann-Pick C disease was dentrimental or neutral instead of beneficial. Prevention of neuronal loss was instead mediated by providing NPC1 to neurons. We used microarrays to detail the global change in gene expression of the cerebellum in Niemann-Pick C disease animals, Niemann-Pick C disease animals with Ccl3 gene deletion, and Niemann-Pick C disease animals with Purkinje neuron-specific NPC1-YFP rescue.
Project description:Niemann Pick Type C1 (NPC1) is an endolysosomal transmembrane protein involved in the export of cholesterol and sphingolipids to other cellular compartments such as the endoplasmic reticulum and plasma membrane. NPC1 loss of function is the major cause of NPC disease, a rare lysosomal storage disorder characterized by an abnormal accumulation of lipids in the late endosomal/lysosomal network, mitochondrial dysfunction, and impaired autophagy. NPC phenotypes are conserved in yeast lacking Ncr1, orthologue of human NPC1, leading to premature ageing. Herein, we performed a phosphoproteomic analysis to investigate the effect of Ncr1 loss on cellular functions mediated by the yeast lysosome-like vacuoles. Our results revealed changes in vacuolar membrane proteins that are associated mostly with vesicle biology (fusion, transport, organization), autophagy and ion homeostasis, including iron, manganese, and calcium. Consistently, the Cytoplasm to vacuole targeting (Cvt) pathway was increased in ncr1∆ cells and autophagy was compromised despite TORC1 inhibition. Moreover, ncr1∆ cells exhibited iron overload mediated by the low‑iron sensing transcription factor Aft1. Iron deprivation restored the autophagic flux of ncr1∆ cells and increased its chronological lifespan and oxidative stress resistance. These results implicate iron overload on autophagy impairment, oxidative stress sensitivity and cell death in the yeast model of NPC1.
Project description:Niemann-Pick type C (NPC) disease is an inherited, progressive neurodegenerative disorder principally caused by mutations in the NPC1 gene. NPC disease is characterized by the accumulation of unesterified cholesterol in the late endosomes (LE) and lysosomes (LE) (LE/LY). Vorinostat, a histone deacetylase inhibitor (HDACi), restores cholesterol homeostasis in fibroblasts derived from NPC patients; however, the exact mechanism by which Vorinostat restores cholesterol level is not known yet. In this study, we performed comparative proteomic profiling of the response of NPC1-I1061T fibroblasts to Vorinostat. After stringent statistical criteria to filter identified proteins, we observed 202 proteins that are differentially expressed in Vorinostat-treated fibroblasts. These proteins are members of diverse cellular pathways including the endomembrane dependent protein folding-stability-degradation-trafficking axis, energy metabolism, and lipid metabolism. Our study shows that treatment of NPC1-I1061T fibroblasts with Vorinostat not only enhances pathways promoting the folding, stabilization and trafficking of NPC1 (I1061T) mutant to the LE/LY, but alters the expression of lysosomal proteins, specifically the lysosomal acid lipase (LIPA) involved in the LIPA->NPC2->NPC1 based flow of cholesterol from the LE/LY lumen to the LE/LY membrane. We posit that the Vorinostat may modulate numerous pathways that operate in an integrated fashion through epigenetic and post-translational modifications reflecting acetylation/deacetylation balance to help manage the defective NPC1 fold, the function of the LE/LY system and/or additional cholesterol metabolism/distribution pathways, that could globally contribute to improved mitigation of NPC1 disease in the clinic based on as yet uncharacterized principles of cellular metabolism dictating cholesterol homeostasis.
Project description:Niemann-Pick disease type C (NPC) is a rare fatal neurodegenerative lysosomal storage disease caused by mutations of either NPC1 or NPC2. NPC2 is a soluble lysosomal protein that in coordination with NPC1 is responsible for the efflux of unesterified cholesterol from the lysosome. Mutations of both genes cause a similar cellular pathology, that includes the accumulation of unesterified cholesterol and other lipids in the late endosome/lysosome, while reducing cholesterol bioavailability. Here we describe a npc2 null zebrafish model generated by CRISPR/Cas9 gene targeting. Zygotic npc2m/m zebrafish from the intercross of npc2+/m individuals showed significant unesterified cholesterol accumulation at larval stages, and a reduction in body size in adulthood. Additionally, zygotic npc2m/m adults exhibited motor and balance defects shortly before a premature death. These findings mimic defects found in human and mice, however the phenotype at embryonic stages were milder than expected. To address the possible dose protection effects of npc2 mRNA present in the oocyte at the time of fertilization we intercrossed npc2m/m zebrafish to generate Maternal-zygotic (MZ) npc2m/m embryos. MZnpc2m/m zebrafish exhibited significant developmental defects including absent otolith, abnormal head/brain development, curved/twisted body axis, no circulating blood cells, and died by 72 hpf. These developmental defects have not previously been reported in connection with either NPC2 or NPC1. RNA-seq analysis conducted on 30 hpf npc2+/m and MZnpc2m/m embryos revealed a significant reduction in notch3 expression as well as reduction in other downstream genes in the signally pathway such as hey1 and her12 that could be partially rescued by microinjection of a plasmid containing the constitutively active notch3 ICD at the 1-cell stage, suggesting that impaired Notch3 signaling likely underlies some aspects of the developmental defects observed in MZnpc2m/m zebrafish.