Lippincott Williams & Wilkins, Inc., Philadelphia
A Monoclonal Antibody to Amyloid Precursor Protein Induces Neuronal Apoptosis
Article first published online: 18 JAN 2002
Journal of Neurochemistry
Volume 74, Issue 6, pages 2331–2342, June 2000
How to Cite
Rohn, T. T., Ivins, K. J., Bahr, B. A., Cotman, C. W. and Cribbs, D. H. (2000), A Monoclonal Antibody to Amyloid Precursor Protein Induces Neuronal Apoptosis. Journal of Neurochemistry, 74: 2331–2342. doi: 10.1046/j.1471-4159.2000.0742331.x
Abbreviations used: AD, Alzheimer’s disease; anti-BDPc, calpain cleavage site-directed antibody to 150-kDa breakdown product of fodrin; APP, β-amyloid protein precursor; BDP, breakdown product; BSO, buthionine sulfoximine; DMEM, Dulbecco’s modified Eagle’s medium; FAD, familial Alzheimer’s disease; GEE, GSH ethyl ester; SST, staurosporine; Z-VAD-FMK, N-benzyloxycarbonyl-Val-Ala-Asp(O-methyl)-fluoromethyl ketone.
- Issue published online: 18 JAN 2002
- Article first published online: 18 JAN 2002
- Amyloid precursor protein;
- Cortical neurons;
- Alzheimer’s disease
Abstract: Although there is considerable evidence suggesting that altered metabolism of β-amyloid precursor protein (APP) and accumulation of its β-amyloid fragment are key features of Alzheimer’s disease (AD), the normal physiological function of APP remains elusive. We investigated the potential role of APP in neurons using the monoclonal antibody 22C11, which binds to the extracellular domain of the human, rat, or mouse APP. Exposure of cortical neurons to 22C11 induced morphological changes including neurite degeneration, nuclear condensation, and internucleosomal DNA cleavage that were consistent with neurons dying by apoptosis. Supporting a role for 22C11-mediated apoptosis occurring by binding to APP were data demonstrating that preincubation of 22C11 with either purified APP or a synthetic peptide (APP66-81) that contains the epitope for 22C11 significantly attenuated neuronal damage induced by 22C11. The specificity of 22C11 was further supported by data showing no apparent effects of either mouse IgG or the monoclonal antibody P2-1, which is specific for the aminoterminal end of human but not rat APP. In addition, biochemical features indicative of apoptosis were the formation of 120- and 150-kDa breakdown products of fodrin following treatment of cortical neurons with 22C11. Both the morphological and the biochemical changes induced by 22C11 were prevented following pretreatment of neurons with the general caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(O-methyl)-fluoromethyl ketone. Prior incubation of cortical neurons with GSH ethyl ester (GEE), a cell-permeable form of GSH, resulted in complete protection from the 22C11 insult, thus implicating an oxidative pathway in 22C11-mediated neuronal degeneration. This was further supported by the observation that prior treatment of neurons with buthionine sulfoximine, an inhibitor of γ-glutamylcysteinyl synthetase, potentiated the toxic effects of 22C11. Finally, with use of compartmented cultures of hippocampal neurons, it was also demonstrated that selective application of 22C11 caused local neuritic degeneration that was prevented by the addition of GEE to the neuritic compartment. Thus, the binding of a monoclonal antibody to APP initially triggers neurite degeneration that is followed by caspase-dependent apoptosis in neuronal cultures and illustrates a novel property of this protein in neurons that may contribute to the profound neuronal cell death associated with AD.