Methylglyoxal Produced by Amyloid-β Peptide-Induced Nitrotyrosination of Triosephosphate Isomerase Triggers Neuronal Death in Alzheimer's Disease

Article type: Research Article

Authors: Tajes, Marta^a | Eraso-Pichot, Abel^a | Rubio-Moscardó, Fanny^a | Guivernau, Biuse^a | Ramos-Fernández, Eva^a | Bosch-Morató, Mònica^a | Guix, Francesc Xavier^a | Clarimón, Jordi^b | Miscione, Gian Pietro^{c; d} | Boada, Mercé^{e; f} | Gil-Gómez, Gabriel^g | Suzuki, Toshiharu^h | Molina, Henrikⁱ | Villà-Freixa, Jordi^{c; j} | Vicente, Rubén^a | Muñoz, Francisco J.^{a; *}

Affiliations: [a] Laboratory of Molecular Physiology and Channelopathies, Departament de Ciències Experimentals i de la Salut (DCEXS), Universitat Pompeu Fabra (UPF), Barcelona, Spain | [b] Alzheimer Laboratory, Neurology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Spain | [c] Computational Biochemistry and Biophysics Laboratory, Research Program on Biomedical Informatics, DCEXS, IMIM/UPF, Barcelona, Spain | [d] Dipartimento di Chimica “G. Ciamician”, Universitá degli Studi di Bologna, Italy | [e] Memory Clinic, Fundació ACE. Institut Català de Neurociències Aplicades, Barcelona, Spain | [f] Neurology Department, Hospital Universitari Vall d'Hebron-Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain | [g] IMIM (Institut Hospital del Mar d'Investigacions Mèdiques), Barcelona, Spain | [h] Laboratory of Neuroscience, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan | [i] Proteomics Unit, DCEXS, UPF and Centre de Regulació Genómica (CRG), Barcelona, Spain | [j] Escola Politécnica Superior, Universitat de Vic, Spain

Correspondence: [*] Correspondence to: Dr. Francisco J. Muñoz, Lab. Fisiologia Molecular i Canalopaties, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra, C/ Dr. Aiguader 88, Barcelona 08003, Spain. Tel.: +34 93 316 08 52; Fax: +34 93 316 09 01; E-mail: paco.munoz@upf.edu.

Abstract: Amyloid-β peptide (Aβ) aggregates induce nitro-oxidative stress, contributing to the characteristic neurodegeneration found in Alzheimer's disease (AD). One of the most strongly nitrotyrosinated proteins in AD is the triosephosphate isomerase (TPI) enzyme which regulates glycolytic flow, and its efficiency decreased when it is nitrotyrosinated. The main aims of this study were to analyze the impact of TPI nitrotyrosination on cell viability and to identify the mechanism behind this effect. In human neuroblastoma cells (SH-SY5Y), we evaluated the effects of Aβ42 oligomers on TPI nitrotyrosination. We found an increased production of methylglyoxal (MG), a toxic byproduct of the inefficient nitro-TPI function. The proapoptotic effects of Aβ42 oligomers, such as decreasing the protective Bcl2 and increasing the proapoptotic caspase-3 and Bax, were prevented with a MG chelator. Moreover, we used a double mutant TPI (Y165F and Y209F) to mimic nitrosative modifications due to Aβ action. Neuroblastoma cells transfected with the double mutant TPI consistently triggered MG production and a decrease in cell viability due to apoptotic mechanisms. Our data show for the first time that MG is playing a key role in the neuronal death induced by Aβ oligomers. This occurs because of TPI nitrotyrosination, which affects both tyrosines associated with the catalytic center.

Keywords: Alzheimer's disease, amyloid, apoptosis, methylglyoxal, 3-nitrotyrosine, triose-phosphate isomerase

DOI: 10.3233/JAD-131685

Journal: Journal of Alzheimer's Disease, vol. 41, no. 1, pp. 273-288, 2014