title: Simulated microgravity promotes cellular senescence via oxidant stress in rat PC12 cells.
abstract: Microgravity has a unique effect on biological organisms. Organs exposed to microgravity display cellular senescence, a change that resembles the aging process. To directly investigate the influence of simulated microgravity on neuronal original rat PC12 cells, we used a rotary cell culture system that simulates the microgravity environment on the earth. We found that simulated microgravity induced partial G1 phase arrest, upregulated senescence-associated beta-galactosidase (SA-beta-gal) activity, and activated both p53 and p16 protein pathways linked to cell senescence. The amount of reactive oxygen species (ROS) was also increased. The activity of intracellular antioxidant enzymes, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT), was all significantly increased at 12h after the microgravity onset, yet decreased at 96h. Furthermore, concomitant block of ROS by the antioxidant N-acetylcysteine significantly inhibited the microgravity-induced upregulation of SA-beta-gal activity. These results suggest that exposure to simulated microgravity induces cellular senescence in PC12 cells via an increased oxidant stress.
authors.affiliation: Department of Neurobiology, Harbin Medical University, Heilongjiang, China.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Wang
authors.forename: Jifei
authors.initials: J
authors.lastname: Zhang
authors.forename: Shasha
authors.initials: S
authors.lastname: Bai
authors.forename: Guangyou
authors.initials: G
authors.lastname: Wang
authors.forename: Lili
authors.initials: L
authors.lastname: Mu
authors.forename: Bo
authors.initials: B
authors.lastname: Sun
authors.forename: Dandan
authors.initials: D
authors.lastname: Wang
authors.forename: Qingfei
authors.initials: Q
authors.lastname: Kong
authors.forename: Yumei
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiuhua
authors.initials: X
authors.lastname: Yao
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Hulun
authors.initials: H
authors.lastname: Li
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D015153:Blotting, Western; D002374:Catalase / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D016922:Cellular Senescence / Q000502:physiology*; D005434:Flow Cytometry; D016166:Free Radical Scavengers / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000378:metabolism; D009474:Neurons / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology*; D016716:PC12 Cells; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D014893:Weightlessness / Q000009:adverse effects*; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D001616:beta-Galactosidase; D000111:Acetylcysteine