title: Interleukin-6 protects PC12 cells from 4-hydroxynonenal-induced cytotoxicity by increasing intracellular glutathione levels.
abstract: Oxidative stress plays an important role in neuronal cell death associated with many different neurodegenerative conditions, and it is reported that 4-hydroxynonenal (HNE), an aldehydic product of membrane lipid peroxidation, is a key mediator of neuronal cell death induced by oxidative stress. Previously, we have demonstrated that interleukin-6 (IL-6) protects PC12 cells from serum deprivation and 6-hydroxydopamine-induced toxicity. Therefore, in the present study, we examined the effects of interleukins on HNE toxicity in PC12 cells. Exposure of PC12 cells to HNE resulted in a decrease in levels of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction, which was due to necrotic and apoptotic cell death. Addition of IL-6 24 h before HNE treatment provided a concentration-dependent protection against HNE toxicity, whereas neither IL-1beta nor IL-2 had any effect. Addition of glutathione (GSH)-ethyl ester, but not superoxide dismutase or catalase, before HNE treatment to the culture medium protected PC12 cells from HNE toxicity. We found that IL-6 increases intracellular GSH levels and the activity of gamma-glutamylcysteine synthetase (gamma-GCS) in PC12 cells. Buthionine sulfoximine (BSO), an inhibitor of gamma-GCS, reversed the protective effect of IL-6 against HNE toxicity. These results suggest that IL-6 protects PC12 cells from HNE-induced cytotoxicity by increasing intracellular levels of GSH.
authors.affiliation: Department of Neuropsychopharmacology and Hospital Pharmacy, Nagoya University Graduate School of Medicine, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Nakajima
authors.forename: Kiyofumi
authors.initials: K
authors.lastname: Yamada
authors.forename: Li-Bo
authors.initials: LB
authors.lastname: Zou
authors.forename: Yijin
authors.initials: Y
authors.lastname: Yan
authors.forename: Makoto
authors.initials: M
authors.lastname: Mizuno
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Nabeshima
mesh_terms: D000447:Aldehydes / Q000633:toxicity*; D000818:Animals; D019328:Buthionine Sulfoximine / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D017931:DNA Primers / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005721:Glutamate-Cysteine Ligase / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D006131:Growth Inhibitors / Q000633:toxicity*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007375:Interleukin-1 / Q000494:pharmacology; D007376:Interleukin-2 / Q000494:pharmacology; D015850:Interleukin-6 / Q000494:pharmacology*; D018696:Neuroprotective Agents / Q000494:pharmacology*; D018384:Oxidative Stress; D016716:PC12 Cells / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000447:Aldehydes; D017931:DNA Primers; D004791:Enzyme Inhibitors; D006131:Growth Inhibitors; D007375:Interleukin-1; D007376:Interleukin-2; D015850:Interleukin-6; D018696:Neuroprotective Agents; D019328:Buthionine Sulfoximine; D005721:Glutamate-Cysteine Ligase; D005978:Glutathione; C027576:4-hydroxy-2-nonenal