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Analysis of the amyloid precursor protein role in neuritogenesis reveals a biphasic SH ‐ SY 5Y neuronal cell differentiation model
Author(s) -
Rocha Joana Fernandes,
Cruz e Silva Odete A. B.,
Vieira Sandra Isabel
Publication year - 2015
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.13133
Subject(s) - sh sy5y , amyloid precursor protein , chemistry , microbiology and biotechnology , neuroscience , cell , biochemistry , biology , alzheimer's disease , cell culture , medicine , neuroblastoma , genetics , disease
The existence of an intrinsic programme controlling neuritogenesis and activated during early neuronal differentiation and regeneration stages is well established. However, the identity and role of each molecular player and event, as well as how such a programme is modified by environmental signals, remain a focus of research. The amyloid precursor protein ( APP ) is a neuromodulator of the developing and mature nervous system, although in a highly complex manner which is far from clear. To study APP ‐induced neuritogenesis, the retinoic acid ( RA )‐induced SH ‐ SY 5Y cell differentiation model was first minutely characterized in terms of RA dose, morphological outputs and relevant biochemical markers. The findings reported here unveiled two differentiation phases for the 10 μM RA dose: 1–4 (4 days excluded) and 4–8 days, clearly defined by fold increases in the ratio between APP and acetylated Tubulin. Moreover, we describe, for the first time, a unique peak of secreted APP ( sAPP )/ APP ratio in the first phase. Subsequent APP and sAPP modulations confirmed that a high sAPP / APP ratio potentiates the elongation of smaller processes at the earlier neuritogenic phase. This sAPP / APP ratio drops in the second phase, as holo APP levels increase to assist the maintenance of the longer neurites, potentially via their stabilization.We show that SH‐SY5Y cells differentiation (‘Diff.’) induced by 10 µM retinoic acid (RA) is biphasic, and describe the behaviour of the Alzheimer's amyloid precursor protein APP and its secreted sAPP fragment in this model. This includes a unique sAPP/APP peak in the first phase, and a plateau for holoAPP in the second phase, both related to APP neuritogenic functions.