title: Effect of Prolonged Simulated Microgravity on Metabolic Proteins in Rat Hippocampus: Steps toward Safe Space Travel.
abstract: Mitochondria are not only the main source of energy in cells but also produce reactive oxygen species (ROS), which result in oxidative stress when in space. This oxidative stress is responsible for energy imbalances and cellular damage. In this study, a rat tail suspension model was used in individual experiments for 7 and 21 days to explore the effect of simulated microgravity (SM) on metabolic proteins in the hippocampus, a vital brain region involved in learning, memory, and navigation. A comparative (18)O-labeled quantitative proteomic strategy was used to observe the differential expression of metabolic proteins. Forty-two and sixty-seven mitochondrial metabolic proteins were differentially expressed after 21 and 7 days of SM, respectively. Mitochondrial Complex I, III, and IV, isocitrate dehydrogenase and malate dehydrogenase were down-regulated. Moreover, DJ-1 and peroxiredoxin 6, which defend against oxidative damage, were up-regulated in the hippocampus. Western blot analysis of proteins DJ-1 and COX 5A confirmed the mass spectrometry results. Despite these changes in mitochondrial protein expression, no obvious cell apoptosis was observed after 21 days of SM. The results of this study indicate that the oxidative stress induced by SM has profound effects on metabolic proteins.
authors.affiliation: School of Life Sciences, Beijing Institute of Technology , No. 5 Zhongguancun South Street, Beijing 100081, P.R. China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Wang
authors.affiliation: School of Life Sciences, Beijing Institute of Technology , No. 5 Zhongguancun South Street, Beijing 100081, P.R. China.
authors.forename: Iqbal
authors.initials: I
authors.lastname: Javed
authors.affiliation: School of Life Sciences, Beijing Institute of Technology , No. 5 Zhongguancun South Street, Beijing 100081, P.R. China.
authors.forename: Yahui
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Life Sciences, Beijing Institute of Technology , No. 5 Zhongguancun South Street, Beijing 100081, P.R. China.
authors.forename: Song
authors.initials: S
authors.lastname: Lu
authors.affiliation: School of Life Sciences, Beijing Institute of Technology , No. 5 Zhongguancun South Street, Beijing 100081, P.R. China.
authors.forename: Guang
authors.initials: G
authors.lastname: Peng
authors.affiliation: School of Life Sciences, Beijing Institute of Technology , No. 5 Zhongguancun South Street, Beijing 100081, P.R. China.
authors.forename: Yongqian
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Life Sciences, Beijing Institute of Technology , No. 5 Zhongguancun South Street, Beijing 100081, P.R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Qing
authors.affiliation: School of Life Sciences, Beijing Institute of Technology , No. 5 Zhongguancun South Street, Beijing 100081, P.R. China.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Deng
mesh_terms: D000328:Adult; D004734:Energy Metabolism; D063990:Gene Ontology; D006624:Hippocampus / Q000378:metabolism*; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress; D020543:Proteome / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D018474:Weightlessness Simulation
chemical_list: D024101:Mitochondrial Proteins; D020543:Proteome; D008315:Malondialdehyde; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase
keywords: hippocampus; mitochondrial metabolic; oxidative stress; proteomics; simulated microgravity (SM)