SSADH Variants Increase Susceptibility of U87 Cells to Mitochondrial Pro-Oxidant Insult.

Succinate semialdehyde dehydrogenase (SSADH) is a mitochondrial enzyme, encoded by , mainly involved in γ-aminobutyric acid (GABA) catabolism and energy supply of neuronal cells, possibly contributing to antioxidant defense. This study aimed to further investigate the antioxidant role of SSADH, and to verify if common SNPs of may affect SSADH activity, stability, and mitochondrial function. In this study, we used U87 glioblastoma cells as they represent a glial cell line.

Oleuropein shows copper complexing properties and noxious effect on cultured SH-SY5Y neuroblastoma cells depending on cell copper content.

The secoiridoid oleuropein is a non-flavonoid polyphenol, found in the fruit, leaves and food derivatives from Olea europea. Like other polyphenols it shows a very low toxicity towards healthy tissues and a protective action against cancer or neurodegeneration, but its mechanism of action is not yet understood. In the present report we have used optical and ESR spectroscopy as well as molecular modelling to demonstrate that oleuropein forms a complex with the transition metal copper; the dysmetabolism of this metal is suspected to be involved in both cancer and neurodegeneration.

Glutaredoxin 1 is a major player in copper metabolism in neuroblastoma cells.

Background: Glutaredoxin 1 (Grx1), a small protein belonging to the thioredoxin family, is involved in redox-regulation since it catalyzes the reduction of protein disulfides and that of mixed disulfides. It was reported to modulate active copper extrusion from cells, by affecting the function of the pumps ATP7A and B. These are components of the network of protein chaperones involved in the control of the homeostasis of copper, an essential, though harmful, metal.

Copper depletion increases the mitochondrial-associated SOD1 in neuronal cells.

The role of copper in the toxicity of mutant copper-dependent enzyme superoxide dismutase (SOD1) found in patients affected with the familial form of amyotrophic lateral sclerosis (fALS) is widely debated. Here we report that treatment of human neuroblastoma cells SH-SY5Y with a specific copper chelator, triethylene tetramine (Trien) induces the decrease of intracellular copper level, paralleled by decreased activity of SOD1. A comparable effect is observed in mouse NSC-34-derived cells, a motoneuronal model, transfected for the inducible expression of either wild-type or G93A mutant human SOD1, one of the mutations associated with fALS.

Inactivation of cytochrome c oxidase by mutant SOD1s in mouse motoneuronal NSC-34 cells is independent from copper availability but is because of nitric oxide.

The copper-enzyme cytochrome c oxidase (Cytox) has been indicated as a primary molecular target of mutant copper, zinc superoxide dismutase (SOD1) in familial amyotrophic lateral sclerosis (fALS); however, the mechanism underlying its inactivation is still unclear. As the toxicity of mutant SOD1s could arise from their selective recruitment to mitochondria, it is conceivable that they might compete with Cytox for the mitochondrial copper pool causing Cytox inactivation. To investigate this issue, we used mouse motoneuronal neuroblastoma x spinal cord cell line-34, stably transfected for the inducible expression of low amounts of wild-type or mutant (G93A, H46R, and H80R) human SOD1s and compared the effects observed on Cytox with those obtained by copper depletion.

Features of ceruloplasmin in the cerebrospinal fluid of Alzheimer's disease patients.

The level of the apo-form of the copper enzyme ceruloplasmin (CP) is an established peripheral marker in diseases associated with copper imbalance. In view of the proposal that disturbances of copper homeostasis may contribute to neurodegeneration associated with Alzheimer's disease (AD), the present work investigates, by Western blot and non-reducing SDS-PAGE followed by activity staining, the features of CP protein, and the copper/CP relationship in cerebrospinal fluid (CSF) and serum of AD patients. Results show that only a fraction of total copper is associated with CP in the CSF, at variance with serum, both in affected and in healthy individuals.

Ceruloplasmin (2-D PAGE) Pattern and Copper Content in Serum and Brain of Alzheimer Disease Patients.

A dysfunction in copper homeostasis seems to occur in Alzheimer's disease (AD). We previously evidenced that an excess of non-ceruloplasmin-copper (NCC) correlated with the main functional, anatomical as well as cerebrospinal markers of the disease. Aim of our study was to investigate ceruloplasmin isoforms as potential actors in this AD copper dysfunction.