Effects of 4-hydroxy-nonenal and Amyloid-beta on expression and activity of endothelin converting enzyme and insulin degrading enzyme in SH-SY5Y cells.
The cerebral accumulation of amyloid-beta (Abeta) is a consistent feature of and likely contributor to the development of Alzheimer's disease (AD). In addition to dysregulated production, increasing experimental evidence suggests reduced catabolism plays an important role in Abeta accumulation. Although endothelin converting enzyme (ECE) and insulin degrading enzyme (IDE) degrade and thus contribute to regulating the steady-state levels of Abeta, how these enzymes are regulated remain poorly understood. In this study, we investigated the effects of 4-hydroxy-nonenal (HNE) and Abeta on the expression and activity of ECE-1 and IDE in human neuroblastoma SH-SY5Y cells. Treatment with HNE or Abeta upregulated ECE-1 mRNA and protein, while IDE was unchanged. Although both ECE-1 and IDE were oxidized within 24 h of HNE or Abeta treatment, ECE-1 catalytic activity was elevated while IDE specific activity was unchanged. The results demonstrated for the first time that both ECE-1 and IDE are substrates of HNE modification induced by Abeta. In addition, the results suggest complex mechanisms underlying the regulation of their enzymatic activity.
Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706, USA.
Rui
R
Wang
Suqing
S
Wang
James S
JS
Malter
Deng-Shun
DS
Wang
D000447:Aldehydes / Q000494:pharmacology*; D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D016282:Aspartic Acid Endopeptidases / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D004305:Dose-Response Relationship, Drug; D000072396:Endothelin-Converting Enzymes; D004789:Enzyme Activation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D047468:Immunoprecipitation; D007339:Insulysin / Q000235:genetics / Q000378:metabolism*; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism*; D009447:Neuroblastoma / Q000201:enzymology / Q000473:pathology; D010446:Peptide Fragments / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism
D000447:Aldehydes; D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; D012333:RNA, Messenger; C075222:amyloid beta-protein (1-42); C462359:tert-4-hydroxy-2-nonenal; D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; D007339:Insulysin; C000606923:ECE1 protein, human; D000072396:Endothelin-Converting Enzymes