Clues to neuro-degeneration in Niemann-Pick type C disease from global gene expression profiling.
BACKGROUND
Niemann-Pick Type C (NPC) disease is a neurodegenerative disease that is characterized by the accumulation of cholesterol and glycosphingolipids in the late endocytic pathway. The majority of NPC cases are due to mutations in the NPC1 gene. The precise function of this gene is not yet known.


RESULTS
Using cDNA microarrays, we analyzed the genome-wide expression patterns of human fibroblasts homozygous for the I1061T NPC1 mutation that is characterized by a severe defect in the intracellular processing of low density lipoprotein-derived cholesterol. A distinct gene expression profile was identified in NPC fibroblasts from different individuals when compared with fibroblasts isolated from normal subjects. As expected, NPC1 mutant cells displayed an inappropriate homeostatic response to accumulated intracellular cholesterol. In addition, a number of striking parallels were observed between NPC disease and Alzheimer's disease.


CONCLUSIONS
Many genes involved in the trafficking and processing of amyloid precursor protein and the microtubule binding protein, tau, were more highly expressed. Numerous genes important for membrane traffic and the cellular regulation of calcium, metals and other ions were upregulated. Finally, NPC fibroblasts exhibited a gene expression profile indicative of oxidative stress. These changes are likely contributors to the pathophysiology of Niemann-Pick Type C disease.
Reddy
Jonathan V
JV
Department of Biochemistry, Stanford University School of Medicine, California, United States of America. pffeffer@stanford.edu
Ganley
Ian G
IG
Pfeffer
Suzanne R
SR
D000544:Alzheimer Disease / Q000209:etiology / Q000378:metabolism; D019943:Amino Acid Substitution; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics*; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism; D020869:Gene Expression Profiling; D006706:Homeostasis; D006720:Homozygote; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins / Q000235:genetics*; D009410:Nerve Degeneration / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D000077296:Niemann-Pick C1 Protein; D052556:Niemann-Pick Disease, Type C / Q000209:etiology* / Q000235:genetics* / Q000378:metabolism; D018384:Oxidative Stress; D017354:Point Mutation; D016875:tau Proteins / Q000378:metabolism
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; C054369:MAPT protein, human; D008562:Membrane Glycoproteins; C106881:NPC1 protein, human; D000077296:Niemann-Pick C1 Protein; D016875:tau Proteins; D002784:Cholesterol; D002118:Calcium