title: In vitro mitochondrial failure and oxidative stress mimic biochemical features of Alzheimer disease.
abstract: Primary cortical neurons exposed to the mitochondrial toxin NaN3 (0.1-3 mM) were submitted to oxidative stress with H2O2 (30-150 μM), to mimic conditions observed in neurodegenerative disorders. The effects of such treatment on a series of parameters useful in characterizing neuronal damage were investigated: (i) the basal release of glutamate, evaluated as (3)H-d-Aspartate efflux, was sharply, concentration-dependently, increased; (ii) the phosphorylation status of intracellular markers known to be involved in the neurodegenerative processes, in particular in Alzheimer disease: tau and GSK3β were increased, as well as the protein level of β-secretase (BACE1) and p35/25 evaluated by Western blotting, while (iii) the cell metabolic activity, measured with the MTT method, was reduced, in a concentration- and time-dependent manner. The latter effect, as well as tau hyperphosphorylation, was prevented both by a mixture of antioxidant drugs (100 μM ascorbic acid, 10 μM trolox, 100 μM glutathione) and by the anti-Alzheimer drug, memantine, 20 μM. Since it is well known that hippocampal cholinergic neurons are particularly affected in Alzheimer disease, the effects of NaN3 and H2O2 were also studied in electrically stimulated rat hippocampal slices, evaluating the (3)H-Choline efflux, as an index of acetylcholine release. The neurotoxic treatment depressed the neurosecretory function and the mixture of antioxidant drugs, as well as memantine, were able to restore it. The neuronal damage induced by the in vitro protocol adopted in the present work displays peculiarities of neurodegenerative disorders, e.g. Alzheimer disease, underlining the role of mitochondrial failure and oxidative stress, which appear to occur upstream the neurodegenerative process; such protocol could be utilized to test the efficacy of neuroprotective treatments.
authors.affiliation: Department of Medical Sciences, Sections of Medical Genetics, University of Ferrara, Via Fossato di Mortara 74, 44121 Ferrara, Italy. svr@unife.it
authors.forename: Rita
authors.initials: R
authors.lastname: Selvatici
authors.forename: Luca
authors.initials: L
authors.lastname: Marani
authors.forename: Silvia
authors.initials: S
authors.lastname: Marino
authors.forename: Anna
authors.initials: A
authors.lastname: Siniscalchi
mesh_terms: D000544:Alzheimer Disease / Q000378:metabolism* / Q000503:physiopathology; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D066298:In Vitro Techniques; D008928:Mitochondria / Q000187:drug effects / Q000502:physiology*; D018696:Neuroprotective Agents / Q000494:pharmacology; D009584:Nitrogen / Q000494:pharmacology; D018384:Oxidative Stress; D010766:Phosphorylation; D051381:Rats; D017207:Rats, Sprague-Dawley; D016875:tau Proteins / Q000378:metabolism
chemical_list: D000975:Antioxidants; D018696:Neuroprotective Agents; D016875:tau Proteins; C003320:sodium nitride; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D038362:Glycogen Synthase Kinase 3; D009584:Nitrogen