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Inhibition of Wnt signaling induces amyloidogenic processing of amyloid precursor protein and the production and aggregation of Amyloid‐β (Aβ) 42 peptides
Author(s) -
TapiaRojas Cheril,
Burgos Patricia V.,
Inestrosa Nibaldo C.
Publication year - 2016
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/jnc.13873
Subject(s) - wnt signaling pathway , amyloid precursor protein , microbiology and biotechnology , chemistry , pathogenesis , amyloid (mycology) , biochemistry of alzheimer's disease , p3 peptide , signal transduction , peptide , alzheimer's disease , biochemistry , biology , medicine , disease , immunology , inorganic chemistry
Alzheimer's disease (AD) is the most common neurodegenerative disorder and the most frequent cause of dementia in the aged population. According to the amyloid hypothesis, the amyloid‐β (Aβ) peptide plays a key role in the pathogenesis of AD. Aβ is generated from the amyloidogenic processing of amyloid precursor protein and can aggregate to form oligomers, which have been described as a major synaptotoxic agent in neurons. Dysfunction of Wnt signaling has been linked to increased Aβ formation; however, several other studies have argued against this possibility. Herein, we use multiple experimental approaches to confirm that the inhibition of Wnt signaling promoted the amyloidogenic proteolytic processing of amyloid precursor protein. We also demonstrate that inhibiting Wnt signaling increases the production of the Aβ 42 peptide, the Aβ 42 /Aβ 40 ratio, and the levels of Aβ oligomers such as trimers and tetramers. Moreover, we show that activating Wnt signaling reduces the levels of Aβ 42 and its aggregates, increases Aβ 40 levels, and reduces the Aβ 42 /Aβ 40 ratio. Finally, we show that the protective effects observed in response to activation of the Wnt pathway rely on β‐catenin‐dependent transcription, which is demonstrated experimentally via the expression of various ‘mutant forms of β‐catenin’. Together, our findings indicate that loss of the Wnt signaling pathway may contribute to the pathogenesis of AD.