Effects of vector-averaged gravity on NF-kappa B activation in human osteoblast-like cells

Environ Med. 1999 Dec;43(1):25-7.

Abstract

We have recently demonstrated that a transcription factor, nuclear factor kappa B (NF-kappa B), plays a key role in the production of cytokine and cell adhesion molecules in osteoblastic cells. In the present study, we investigated the effects of vector-averaged gravity (clinostat rotation) on tumor necrosis factor (TNF)-alpha-induced activation of NF-kappa B in human osteoblastic HOS-TE85 cells. After a 72-hr clinostat culture, the cells were treated with TNF-alpha for 30 min. Electrophoretic mobility shift assay using the nuclear extracts revealed that the DNA-binding activity of NF-kappa B was substantially reduced in clinostat-cultured cells compared with the stationary control. Concomitantly, the transactivation of NF-kappa B was examined by a transfection study. The cells were transfected with a plasmid expressing a luciferase reporter gene driven by multimerized NF-kappa B sites. They were cultured in the clinostat for 48-hr, followed by a 4-hr treatment with TNF-alpha. Clinostat culture resulted in a significant decrease in the luciferase activities, being consistent with the decreased binding of NF-kappa B. These results indicate that exposure of HOS-TE85 cells to vector-averaged gravity impairs NF-kappa B activation by TNF-alpha.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA / metabolism
  • Gravitation
  • Humans
  • Luciferases / metabolism
  • NF-kappa B / metabolism*
  • Osteoblasts / cytology
  • Osteoblasts / metabolism*
  • Rotation*
  • Tumor Cells, Cultured
  • Tumor Necrosis Factor-alpha / metabolism*
  • Weightlessness Simulation*

Substances

  • NF-kappa B
  • Tumor Necrosis Factor-alpha
  • DNA
  • Luciferases