TNF-alpha-dependent activation of NF-kappa B in human osteoblastic HOS-TE85 cells is repressed in vector-averaged gravity using clinostat rotation.
Effects of vector-averaged gravity on tumor necrosis factor (TNF)-alpha-dependent activation of nuclear factor kappa B (NF-kappa B) in human osteoblastic HOS-TE85 cells were investigated by culturing the cells using clinostat rotation (clinorotation). Cell cultures were rotated for 72 h at 40 rpm in a clinostat. At the end of clinorotation, the cells were treated with TNF-alpha for 30 min under stationary conditions. Electrophoretic mobility shift assays revealed that TNF-alpha-dependent activation of NF-kappa B was markedly reduced in the clinorotated cells when compared with the cells in control stationary cultures or after horizontal rotation (motional controls). The NF-kappa B-dependent transactivation was also impaired in the clinorotated cells, as evidenced by a transient transfection assay with a reporter plasmid containing multimerized NF-kappa B sites. Consistent with these findings, the TNF-alpha-dependent induction of endogenous NF-kappa B-responsive genes p105, I kappa B-alpha, and IL-8, was significantly attenuate in clinorotated cells. These results demonstrate that vector-averaged gravity inhibits the responsiveness of osteoblasts to TNF-alpha by repressing NF-kappa B activation.
Kobayashi
K
K
Department of Endocrinology and Metabolism, Division of Molecular and Cellular Adaptation, Nagoya University, Japan.
Kambe
F
F
Kurokouchi
K
K
Sakai
T
T
Ishiguro
N
N
Iwata
H
H
Koga
K
K
Gruener
R
R
Seo
H
H
D001483:Base Sequence; D002455:Cell Division; D002460:Cell Line; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D016762:Genes, fos; D006112:Gravitation; D006801:Humans; D006868:Hydrolysis; D020672:I-kappa B Proteins; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism* / Q000502:physiology; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D015533:Transcriptional Activation / Q000502:physiology; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D017931:DNA Primers; D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D014409:Tumor Necrosis Factor-alpha; D000072000:NF-KappaB Inhibitor alpha