SSADH Variants Increase Susceptibility of U87 Cells to Mitochondrial Pro-Oxidant Insult
Open Access
- 19 June 2020
- journal article
- research article
- Published by MDPI AG in International Journal of Molecular Sciences
- Vol. 21 (12), 4374
- https://doi.org/10.3390/ijms21124374
Abstract
Succinate semialdehyde dehydrogenase (SSADH) is a mitochondrial enzyme, encoded by ALDH5A1, 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 ALDH5A1 may affect SSADH activity, stability, and mitochondrial function. In this study, we used U87 glioblastoma cells as they represent a glial cell line. These cells were transiently transfected with a cDNA construct simultaneously harboring three SNPs encoding for a triple mutant (TM) SSADH protein (p.G36R/p.H180Y/p.P182L) or with wild type (WT) cDNA. SSADH activity and protein level were measured. Cell viability, lipid peroxidation, mitochondrial morphology, membrane potential (ΔΨ), and protein markers of mitochondrial stress were evaluated upon Paraquat treatment, in TM and WT transfected cells. TM transfected cells show lower SSADH protein content and activity, fragmented mitochondria, higher levels of peroxidized lipids, and altered ΔΨ than WT transfected cells. Upon Paraquat treatment, TM cells show higher cell death, lipid peroxidation, 4-HNE protein adducts, and lower ΔΨ, than WT transfected cells. These results reinforce the hypothesis that SSADH contributes to cellular antioxidant defense; furthermore, common SNPs may produce unstable, less active SSADH, which could per se negatively affect mitochondrial function and, under oxidative stress conditions, fail to protect mitochondria.Keywords
This publication has 30 references indexed in Scilit:
- Succinic semialdehyde dehydrogenase deficiency: The combination of a novel ALDH5A1 gene mutation and a missense SNP strongly affects SSADH enzyme activity and stabilityMolecular Genetics and Metabolism, 2018
- Towards a Better Understanding of GABAergic Remodeling in Alzheimer’s DiseaseInternational Journal of Molecular Sciences, 2017
- SSADH deficiency in an Italian family: a novel ALDH5A1 gene mutation affecting the succinic semialdehyde substrate binding siteMetabolic Brain Disease, 2017
- Succinic semialdehyde dehydrogenase deficiency (SSADHD): Pathophysiological complexity and multifactorial trait associations in a rare monogenic disorder of GABA metabolismNeurochemistry International, 2016
- Defects in GABA metabolism affect selective autophagy pathways and are alleviated by mTOR inhibitionEMBO Molecular Medicine, 2014
- Unsaturated lipid peroxidation-derived aldehydes activate autophagy in vascular smooth-muscle cellsBiochemical Journal, 2008
- Evidence for oxidative stress in tissues derived from succinate semialdehyde dehydrogenase‐deficient miceJournal of Inherited Metabolic Disease, 2007
- Mutational spectrum of the succinate semialdehyde dehydrogenase (ALDH5A1) gene and functional analysis of 27 novel disease-causing mutations in patients with SSADH deficiencyHuman Mutation, 2003
- Oxidation of 4‐hydroxy‐2‐nonenal by succinic semialdehyde dehydrogenase (ALDH5A)Journal of Neurochemistry, 2003
- The mechanism of mitochondrial membrane potential retention following release of cytochrome c in apoptotic GT1-7 neural cellsCell Death & Differentiation, 2001