GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com


Jump to: navigation, search

Mentlein, R, Ludwig, R and Martensen, I (1998) Proteolytic degradation of Alzheimer's disease amyloid beta-peptide by a metalloproteinase from microglia cells. J. Neurochem. 70:721-6


The cerebral deposition of amyloid beta-peptide (A beta) is a histopathological characteristic of Alzheimer's disease. Because an impaired clearance of A beta might be involved in the disease, we investigated the proteolytic degradation of synthetic A beta (40-residue peptide) in cultures of glial cells and characterized a protease involved. Whereas rat astrocytes had a very low degradation capacity, cultivated rat microglia cells cleaved A beta. Microglia activity was considerably enhanced by stimulation with lipopolysaccharide and to a lesser extent by phorbol esters. Most of the A beta-degrading activity was released into the medium. By use of selective inhibitors the protease was characterized as a metalloprotease of approximately 200 kDa that was different from neutral endopeptidase (a neuropeptide-degrading enzyme), matrix metalloproteases, or macrophage elastase. Its activity was efficiently reduced by four hydroxamic acid-based zinc-metalloprotease inhibitors that have been shown to inhibit membrane protein secretases (disintegrins). We conclude that activated microglia cells might impair amyloid plaque formation by release of a metalloprotease that degrades soluble A beta, before polymerization.




Amyloid beta-Peptides/metabolism; Animals; Animals, Newborn; Cells, Cultured; Cerebral Cortex/cytology; Cerebral Cortex/enzymology; Cytokines/pharmacology; Humans; Kinetics; Lipopolysaccharides/pharmacology; Metalloendopeptidases/metabolism; Microglia/cytology; Microglia/drug effects; Microglia/enzymology; Peptide Fragments/metabolism; Protease Inhibitors/pharmacology; Rats; Rats, Wistar; Substrate Specificity



Gene product Qualifier GO Term Evidence Code with/from Aspect Extension Notes Status


GO:0001540: beta-amyloid binding



FIG. 6. Molecular mass determination of A/I-degrading activity from microglia-conditioned medium. Microglia cells were stimulated with LPS.

CACAO 5939

See also


See Help:References for how to manage references in GONUTS.