Glutathione level regulates HNE-induced genotoxicity in human erythroleukemia cells

Abstract

4-hydroxy-trans-2-nonenal (HNE) is one of the most abundant and toxic lipid aldehydes formed during lipid peroxidation by reactive oxygen species. We have investigated the genotoxic effects of HNE and its regulation by cellular glutathione (GSH) levels in human erythroleukemia (K562) cells. Incubation of K562 cells with HNE (5-10 microM) significantly elicited a 3- to 5-fold increased DNA damage in a time- and dose-dependent manner as measured by comet assay. Depletion of GSH in cells by L-buthionine-[S,R]-sulfoximine (BSO) significantly increased HNE-induced DNA damage, whereas supplementation of GSH by incubating the cells with GSH-ethyl ester significantly decreased HNE-induced genotoxicity. Further, overexpression of mGSTA4-4, a HNE-detoxifying GST isozyme, significantly prevented HNE-induced DNA damage in cells, and ablation of GSTA4-4 and aldose reductase with respective siRNAs further augmented HNE-induced DNA damage. These results suggest that the genotoxicity of HNE is highly dependent on cellular GSH/GST/AR levels and favorable modulation of the aldehyde detoxification system may help in controlling the oxidative stress-induced complications.

Physiological and Pharmacological Significance of Glutathione-Conjugate Transport

“…The inhibition of the transport functions of RalBP1 interacting proteins, such as POB1 and HSF-1, also leads to apoptosis of cancer cells, which further supports the role of 4-HNE and GS-HNE as regulatory signals for other cellular processes (Yadav et al, , 2008. Among the metabolites of 4-HNE, the involvement of GS-DHN formed by the reduction of GS-HNE by aldose reductase in regulation of nuclear factor (NF) kB-associated signaling was demonstrated, and it was shown that blocking the formation of GS-DHN by aldose reductase inhibitors blocks the proliferation of prostate and colon cancer cells.…”

“…Studies with RLIP76-depleted animals show increased tissue lipid hydroperoxides, alkenals, and their GS-E, as well as marked rise in heat-shock proteins (Awasthi et al, 2003a;Yadav et al, 2007Yadav et al, , 2008. One of the known functions of RLIP76 is to regulate the transcriptional activity of HSF-1 by sequestering it (Hu & Mevechi, 2003;Singhal et al, 2008b).…”

Lipid Peroxidation by-Products and the Metabolic Syndrome

“…Several studies were indeed successful in protecting cultured cells from the deleterious effects of oxidative stress through an increase in intracellular pools of reduced glutathione. This strategy was particularly efficient to protect the cells against the deleterious effects of HNE (Yadav et al, 2008;Jia et al, 2009b;Pillon et al, 2012).…”

In Utero Exposure to Histological Chorioamnionitis Primes the Exometabolomic Profiles of Preterm CD4+ T Lymphocytes

“…This molecule is largely depleted through GSH conjugation, which is catalyzed by glutathione S-transferase 48, 49 . Consequently, the neutralization/detoxification process has been shown to be highly dependent on GSH levels 50 . Current evidence suggests that GSH is also of great importance to the initiation and progression of CD4 + T lymphocyte activation 51–54 .…”