title: Differential translocation of nuclear factor-kappaB in a cardiac muscle cell line under gravitational changes.
abstract: Microgravity (micro-g) environments have been shown to elicit dysregulation of specific genes in a wide assay of cell types. It is known that the activation of transcription factors and molecular signaling pathways influence various physiological outcomes associated with stress and adaptive responses. Nuclear factor-kappa B (NF-kappaB) is one of the most prevailing oxidation-sensitive transcription factors. It is hypothesized that simulated microgravity would activate NF-kappaB and its downstream transcriptional networks, thus suggesting a role for NF-kappaB in microgravity induced muscle atrophy. To investigate the activation of NF-kappaB in a rat cardiac cell line (H9c2) under micro-g, rotating wall vessel bioreactors were used to simulate micro-g conditions. Western blotting revealed that mean nuclear translocation of NF-kappaB p65 subunit was 69% for micro-g and 46% for unit-g dynamic control as compared with a 30 min TNF-alpha positive control (p<0.05, n=3). The results from western blots were confirmed by enzyme-linked immunosorbent assay, which showed 66% for micro-g and 45% for dynamic control as compared with positive control (p<0.05, n=3). These results show significant differential translocation of NF-kappaB p65 under simulated micro-g. These results may be expanded upon to explain physiological changes such as muscle atrophy and further identify the regulatory pathways and effector molecules activated under exposure to micro-g.
authors.affiliation: Department of Mechanical Engineering, University of Cincinnati, Cincinnati, OH 45221, USA.
authors.forename: Ohwon
authors.initials: O
authors.lastname: Kwon
authors.forename: Michael
authors.initials: M
authors.lastname: Tranter
authors.forename: W Keith
authors.initials: WK
authors.lastname: Jones
authors.forename: John M
authors.initials: JM
authors.lastname: Sankovic
authors.forename: Rupak K
authors.initials: RK
authors.lastname: Banerjee
mesh_terms: D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D006112:Gravitation; D006801:Humans; D032383:Myocytes, Cardiac / Q000502:physiology*; D021381:Protein Transport / Q000502:physiology; D051996:Transcription Factor RelA / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology
chemical_list: D051996:Transcription Factor RelA; D014409:Tumor Necrosis Factor-alpha