Ogura T, Esumi H
Investigative Treatment Division, National Cancer Center Research Institute, Chiba, Japan.
Neuroreport. 1996 Mar 22;7(4):853-6. doi: 10.1097/00001756-199603220-00003.
The human neuroblastoma cell line NB-39-nu expressed mRNA coding for inducible nitric oxide synthase (iNOS) following treatment with a combination of interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha). The level of iNOS mRNA peaked 24 h after stimulation and had declined by about 25% after 48 h. Trace levels of iNOS mRNA were detected after treatment with IFN-gamma alone, and its mRNA level was synergistically enhanced by simultaneous treatment with TNF-alpha. Neither bacterial lipopolysaccharide nor interleukin-1 beta (IL-1 beta) showed synergistic effects as great as that of TNF-alpha on iNOS gene expression. Dexamethasone inhibited the induction of iNOS mRNA by IFN-gamma and TNF-alpha. Induction of iNOS was confirmed by NADPH-diaphorase staining and by immunostaining with human iNOS-specific antibody.