title: Phenyl 2-pyridyl ketoxime induces cellular senescence-like alterations via nitric oxide production in human diploid fibroblasts.
abstract: Phenyl-2-pyridyl ketoxime (PPKO) was found to be one of the small molecules enriched in the extracellular matrix of near-senescent human diploid fibroblasts (HDFs). Treatment of young HDFs with PPKO reduced the viability of young HDFs in a dose- and time-dependent manner and resulted in senescence-associated β-galactosidase (SA-β-gal) staining and G2/M cell cycle arrest. In addition, the levels of some senescence-associated proteins, such as phosphorylated ERK1/2, caveolin-1, p53, p16(ink4a), and p21(waf1), were elevated in PPKO-treated cells. To monitor the effect of PPKO on cell stress responses, reactive oxygen species (ROS) production was examined by flow cytometry. After PPKO treatment, ROS levels transiently increased at 30 min but then returned to baseline at 60 min. The levels of some antioxidant enzymes, such as catalase, peroxiredoxin II and glutathione peroxidase I, were transiently induced by PPKO treatment. SOD II levels increased gradually, whereas the SOD I and III levels were biphasic during the experimental periods after PPKO treatment. Cellular senescence induced by PPKO was suppressed by chemical antioxidants, such as N-acetylcysteine, 2,2,6,6-tetramethylpiperidinyloxy, and L-buthionine-(S,R)-sulfoximine. Furthermore, PPKO increased nitric oxide (NO) production via inducible NO synthase (iNOS) in HDFs. In the presence of NOS inhibitors, such as L-NG-nitroarginine methyl ester and L-NG-monomethylarginine, PPKO-induced transient NO production and SA-β-gal staining were abrogated. Taken together, these results suggest that PPKO induces cellular senescence in association with transient ROS and NO production and the subsequent induction of senescence-associated proteins.
authors.affiliation: Drug & Disease Target Group, Division of Bioconvergence Analysis, Korea Basic Science Institute, Daejeon, 305-333, Korea.
authors.forename: Kyeong Eun
authors.initials: KE
authors.lastname: Yang
authors.affiliation: Drug & Disease Target Group, Division of Bioconvergence Analysis, Korea Basic Science Institute, Daejeon, 305-333, Korea.
authors.forename: Hyun-Jin
authors.initials: HJ
authors.lastname: Jang
authors.affiliation: Department of Physiology, Korea University College of Medicine, Seoul, 02841, Korea.
authors.forename: In-Hu
authors.initials: IH
authors.lastname: Hwang
authors.affiliation: Drug & Disease Target Group, Division of Bioconvergence Analysis, Korea Basic Science Institute, Daejeon, 305-333, Korea.
authors.forename: Young-Ho
authors.initials: YH
authors.lastname: Chung
authors.affiliation: Drug & Disease Target Group, Division of Bioconvergence Analysis, Korea Basic Science Institute, Daejeon, 305-333, Korea.
authors.forename: Jong-Soon
authors.initials: JS
authors.lastname: Choi
authors.affiliation: Department of Oral Biochemistry, Dental Science Research Institute, Chonnam National University, Gwangju, 500-757, Korea.
authors.forename: Tae-Hoon
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Center for University-Wide Research Facilities, Chonbuk National University, Jeonju, Korea.
authors.forename: Yun-Jo
authors.initials: YJ
authors.lastname: Chung
authors.affiliation: Department of Biochemistry, College of Medicine, Gachon University, Inchon, 406-799, Korea.
authors.forename: Min-Seung
authors.initials: MS
authors.lastname: Lee
authors.affiliation: KM Convergence Research Division, Korea Institute of Oriental Medicine, Daejeon, 305-811, Korea.
authors.forename: Mi Young
authors.initials: MY
authors.lastname: Lee
authors.affiliation: Department of Biochemistry, College of Medicine, Gachon University, Inchon, 406-799, Korea.
authors.forename: Eui-Ju
authors.initials: EJ
authors.lastname: Yeo
authors.affiliation: Drug & Disease Target Group, Division of Bioconvergence Analysis, Korea Basic Science Institute, Daejeon, 305-333, Korea.
authors.forename: Ik-Soon
authors.initials: IS
authors.lastname: Jang
mesh_terms: D016922:Cellular Senescence / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004790:Enzyme Induction / Q000187:drug effects; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006801:Humans; D059566:M Phase Cell Cycle Checkpoints / Q000187:drug effects; D009569:Nitric Oxide / Q000096:biosynthesis*; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis; D010091:Oximes / Q000494:pharmacology*; D061251:Primary Cell Culture; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D010091:Oximes; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II
keywords: cellular senescence; human diploid fibroblast; nitric oxide; phenyl 2-pyridyl ketoxime; reactive oxygen species