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.
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.
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.
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
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: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.
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.
Project description:Niemann-Pick type C (NPC) disease is an inherited lysosomal storage disorder mainly driven by mutations in NPC1 gene, causing lipid accumulation within late endosomes/lysosomes, and resulting in progressive neurodegeneration. To study the effect of NPC1 deficiency on the innate immune system, we performed proteomics on bone-marrow derived macrophages (BMDMs) of NPC1 KO and WT mice. Without further treatment or activation, BMDMs of NPC1 KO mice showed alterations mainly related to cholesterol metabolism, which is in line with the intracellular cholesterol transport function of NPC1.
Project description:Background: Niemann-Pick type C is a rare autosomal recessive lysosomal storage disorder presenting aggravating neurologic symptoms due degeneration of specific types of CNS neurons. At present, it is not well understood how neurons react to NPC1 deficiency and why some neuronal cell types are more vulnerable than others. Purpose: We took aimed to uncover how a specific type of CNS neuron that can be highly purified reacts to NPC1 deficiency based on changes in gene expression. Methods: Retinal ganglion cells were purified from individual one-week old Balb/c mice homozygous for a mutant NPC1 allele (NPC1m1N) and wildtype littermates (n = 4 mice each genotype) using immunopanning. Total RNA was isolated from acutely isolated neurons and subjected to RNAseq using 4 biological replicates for each genotype. Results: Our analysis revealed a strong downregulation of transcripts known to be decreased in mutant mice including Npc1 and Calb1 thus validating our approach. We observed a strong upregulation of genes for cellular cholesterol accretion and the downregulation of those for cholesterol release. Other changes including downregulation genes involved in the immune response and synaptic components. Conclusions: The observed changes suggest that neurons already at one week of age sense a cholesterol deficit because lipids accumulate in the endosomal-lysosomal system and cannot be redistributed intracellularly. Gene expression analysis by RNAseq in retinal ganglion cells acutely purified from eight-days-old NPC1-deficient mice and wildtype littermates