title: 4-hydroxynonenal induces mitochondrial oxidative stress, apoptosis and expression of glutathione S-transferase A4-4 and cytochrome P450 2E1 in PC12 cells.
abstract: An excessive and sustained increase in reactive oxygen species (ROS) production and oxidative stress have been implicated in the pathogenesis of many diseases. In the present study, we have demonstrated that 4-hydroxynonenal (4-HNE), a product of lipid peroxidation, alters glutathione (GSH) pools and induces oxidative stress in PC12 cells in culture. This increase was accompanied by alterations in subcellular ROS and glutathione (GSH) metabolisms. The GSH homeostasis was affected as both mitochondrial and extramitochondrial GSH levels, GSH peroxidase and glutathione reductase activities were inhibited and glutathione S-transferase (GST) activity was increased after 4-HNE treatment. A concentration- and time-dependent increase in cytochrome P450 2E1 (CYP 2E1) activity in the mitochondria and postmitochondrial supernatant was also observed. 4-HNE-induced oxidative stress also caused an increase in the expression of GSTA4-4, CYP2E1 and Hsp70 proteins in the mitochondria. Increased oxidative stress in PC12 cells initiated apoptosis as indicated by the release of mitochondrial cytochrome c, activation of poly-(ADP-ribose) polymerase (PARP), DNA fragmentation and decreased expression of antiapoptotic Bcl-2 proteins. Mitochondrial respiratory and redox functions also appeared to be affected markedly by 4-HNE treatment. These results suggest that HNE-induced oxidative stress and apoptosis might be associated with altered mitochondrial functions and a compromised GSH metabolism and ROS clearance.
authors.affiliation: Department of Biochemistry, Faculty of Medicine and Health Sciences, PO Box 17666, UAE University, Al Ain, United Arab Emirates. h.raza@uaeu.ac.ae
authors.forename: Haider
authors.initials: H
authors.lastname: Raza
authors.forename: Annie
authors.initials: A
authors.lastname: John
mesh_terms: D000447:Aldehydes / Q000633:toxicity*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015853:Cysteine Proteinase Inhibitors / Q000633:toxicity*; D019392:Cytochrome P-450 CYP2E1 / Q000378:metabolism*; D045304:Cytochromes c / Q000378:metabolism; D053938:DNA Fragmentation; D004305:Dose-Response Relationship, Drug; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D005980:Glutathione Reductase / Q000037:antagonists & inhibitors / Q000187:drug effects / Q000378:metabolism; D005982:Glutathione Transferase / Q000187:drug effects* / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects; D016716:PC12 Cells / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000447:Aldehydes; D015853:Cysteine Proteinase Inhibitors; D018840:HSP70 Heat-Shock Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D017382:Reactive Oxygen Species; D011064:Poly Adenosine Diphosphate Ribose; D045304:Cytochromes c; D005979:Glutathione Peroxidase; D019392:Cytochrome P-450 CYP2E1; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D005978:Glutathione; C027576:4-hydroxy-2-nonenal