Antiamyloidogenic and neuroprotective functions of cathepsin B: implications for Alzheimer's disease.

TitleAntiamyloidogenic and neuroprotective functions of cathepsin B: implications for Alzheimer's disease.
Publication TypeJournal Article
Year of Publication2006
AuthorsMueller-Steiner S, Zhou Y, Arai H, Roberson ED, Sun B, Chen J, Wang X, Yu G, Esposito L, Mucke L, Gan L
Date Published2006 Sep 21
KeywordsAge Factors, Alzheimer Disease, Amyloid, Amyloid beta-Peptides, Amyloid beta-Protein Precursor, Animals, Brain, Cathepsin B, Cell Line, Tumor, Female, Humans, Hydrolysis, Male, Mice, Mice, Inbred C57BL, Mice, Knockout, Mice, Transgenic, Microscopy, Confocal, Microscopy, Electron, Mutation, Neurites, Neurons, Peptide Fragments, Plaque, Amyloid

Alzheimer's disease (AD) may result from the accumulation of amyloid-beta (Abeta) peptides in the brain. The cysteine protease cathepsin B (CatB) is associated with amyloid plaques in AD brains and has been suspected to increase Abeta production. Here, we demonstrate that CatB actually reduces levels of Abeta peptides, especially the aggregation-prone species Abeta1-42, through proteolytic cleavage. Genetic inactivation of CatB in mice with neuronal expression of familial AD-mutant human amyloid precursor protein (hAPP) increased the relative abundance of Abeta1-42, worsening plaque deposition and other AD-related pathologies. Lentivirus-mediated expression of CatB in aged hAPP mice reduced preexisting amyloid deposits, even thioflavin S-positive plaques. Under cell-free conditions, CatB effectively cleaved Abeta1-42, generating C-terminally truncated Abeta peptides that are less amyloidogenic. Thus, CatB likely fulfills antiamyloidogenic and neuroprotective functions. Insufficient CatB activity might promote AD; increasing CatB activity could counteract the neuropathology of this disease.

Alternate JournalNeuron
PubMed ID16982417
Grant ListK08 NS054811 / NS / NINDS NIH HHS / United States
K08 NS054811-01 / NS / NINDS NIH HHS / United States
R21 AG024447 / AG / NIA NIH HHS / United States