Induction of nuclear factor kB after low-dose ionizing radiation involves a reactive oxygen intermediate signaling pathway
- Univ. of Texas Health Science Center, San Antonio, TX (United States)
Reactive oxygen intermediates (ROIs) have been found to be the messengers in the activation of the kB transcription regulator in mitogen- or cytokine-stimulated cells, operating in conjunction with or independently of various other mechanisms; these include Ca{sup ++}-dependent and PKC-dependent cytoplasmic signaling pathways. We have recently reported that low-dose ionizing radiation induces NF-kB in human lymphoblastoid 244B cells. Since ionizing radiation generates free radicals in cells, we have investigated whether the ROIs generated by ionizing radiation induce NF-kB activity, and also whether they do so by a similar mechanism as in cells treated with PMA or H{sub 2}O{sub 2}. The results not only confirm a previous observation from our laboratory that low-dose ionizing radiation (0.1-2.0 Gy) activates kB transcription factor transiently with a maximal induction at 0.5 Gy exposure, but also demonstrate mechanistically that the activation of NF-kB by low-dose ionizing radiation can be inhibited considerably by the antioxidant N-acetyl-L-cysteine, indicating that at least the major part of the activation process is mediated by ROIs. These findings support the idea that ROIs can regulate the kB elements which in turn can serve as response elements for oxidant stress. 37 refs., 4 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 79337
- Journal Information:
- Radiation Research, Journal Name: Radiation Research Journal Issue: 1 Vol. 140; ISSN RAREAE; ISSN 0033-7587
- Country of Publication:
- United States
- Language:
- English
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