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New protein kinase C activator regulates amyloid precursor protein processing in vitro by increasing α‐secretase activity
Author(s) -
Yang HongQi,
Pan Jing,
Ba MaoWen,
Sun ZhiKun,
Ma GuoZhao,
Lu GuoQiang,
Xiao Qin,
Chen ShengDi
Publication year - 2007
Publication title -
european journal of neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.346
H-Index - 206
eISSN - 1460-9568
pISSN - 0953-816X
DOI - 10.1111/j.1460-9568.2007.05648.x
Subject(s) - protein kinase c , amyloid precursor protein , chemistry , neprilysin , brefeldin a , amyloid precursor protein secretase , activator (genetics) , kinase , signal transduction , protein kinase a , mapk/erk pathway , microbiology and biotechnology , biochemistry , medicine , alzheimer's disease , enzyme , biology , golgi apparatus , receptor , disease , cell
The beta amyloid (Aβ) cascade has been at the forefront of the hypothesis used to describe the pathogenesis of Alzheimer's disease (AD). It is generally accepted that drugs that can regulate the processing of the amyloid precursor protein (APP) toward the non‐amyloidogenic pathway may have a therapeutic potential. Previous studies have shown that protein kinase C (PKC) hypofunction has an important role in AD pathophysiology. Therefore, the effects of a new PKC activator, α‐APP modulator [(2S,5S)‐(E,E)‐8‐(5‐(4‐(trifluoromethyl)phenyl)‐2,4‐pentadienoylamino)benzolactam (TPPB)], on APP processing were investigated. Using PC12 cells and SH‐SY5Y APP695 cells, it was found that TPPB promoted the secretion of sAPPα without affecting full‐length expression of APP. The increase in sAPPα by TPPB was blocked by inhibitors of PKC, extracellular signal‐regulated kinase (ERK), c‐Jun N‐terminal kinase (JNK) and tyrosine kinase, suggesting the involvement of these signal transduction pathways. TPPB increased α‐secretase activity [a disintegrin and metalloproteinase (ADAM)10 and 17], as shown by direct fluorescence activity detection and Western blot analysis. TPPB‐induced sAPPα release was blocked by the metalloproteinase inhibitor TAPI‐2, furin inhibitor CMK and by the protein‐trafficking inhibitor brefeldin. The results also showed that TPPB decreased β‐secretase activity, Aβ40 release and beta site APP‐cleaving enzyme 1 (BACE1) expression, but did not significantly affect neprilysin (NEP) and insulin‐degrading enzyme (IDE) expression. Our data indicate that TPPB could direct APP processing towards the non‐amyloidogenic pathway by increasing α‐secretase activity, and suggest its therapeutic potential in AD.