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APP carboxyl‐terminal fragment without or with Aβ domain equally induces cytotoxicity in differentiated PC12 cells and cortical neurons
Author(s) -
Lee JeanPyo,
Chang KeunA,
Kim HyeSun,
Kim SungSu,
Jeong SungJin,
Suh YooHun
Publication year - 2000
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(20000515)60:4<565::aid-jnr16>3.0.co;2-i
Subject(s) - senile plaques , programmed cell death , amyloid precursor protein , neurotoxicity , microbiology and biotechnology , biology , transmembrane protein , chemistry , apoptosis , alzheimer's disease , biochemistry , medicine , receptor , disease , organic chemistry , toxicity
Mutations in the β‐amyloid precursor protein (APP) gene cause familial Alzheimer's disease (AD). Although amyloid β peptide (Aβ) is the principal constituent of senile plaques in AD, other cleavage products of APP are also implicated in playing a role in the pathogenesis of AD. C‐terminal fragments of APP (APP‐CTs), that contain complete Aβ sequence, are found in neuritic plaques, neurofibrillary tangles and the cytosol of lymphoblastoid cells obtained from AD patients. Our previous report demonstrated that APP‐CT105 causes death of differentiated PC12 cells and cultured rat cortical neurons (Kim and Suh [1996] J. Neurochem. 67:1172–1182) and induces strong inward currents in Xenopus oocyte (Fraser et al., [1996] J. Neurochem. 66:2034–2040). In the present study, to investigate which domain of APP‐CT105 is responsible for the neurotoxicity, we have made deletion mutants of APP‐CT105 without Aβ and transmembrane domain (TM) or without NPTY domain, a putative endocytosis signaling sequence, using the PCR‐amplified strategy and the recombinant GST‐fusion protein strategy. The effect on cell survival of the deletion mutants of APP‐CT105 (8 μM) was then determined by the LDH and MTT assay. We found that C‐terminal fragment without NPTY significantly causes cell death in NGF‐differentiated PC12 cells and cultured rat cortical neurons. This finding suggests that NPTY may not play an important role in APP‐CT105 mediated neurotoxicity. We found, however, that C‐terminal fragment without Aβ and TM significantly induces neuronal cell death. Our results suggest that in addition to Aβ, C‐terminal fragment of APP without Aβ and TM domain itself may also participate in the neuronal degeneration in AD. J. Neurosci. Res. 60:565–570, 2000 © 2000 Wiley‐Liss, Inc.