Superoxide dismutase amplifies organismal sensitivity to ionizing radiation

Superoxide dismutase amplifies organismal sensitivity to ionizing radiation.

Although increased superoxide dismutase (SOD) activity is often associated with enhanced resistance of cells and organisms to oxidant challenges, few direct tests of the antioxidant importance of this enzyme have been carried out. To assess the importance of SOD in defending against gamma-radiation, we employed Escherichia coli with deficient, normal, and super-normal enzyme activities. Surpris...

Superoxide dismutase Superoxide dismutase

Short Telomeres Result in Organismal Hypersensitivity to Ionizing Radiation in Mammals

Here we show a correlation between telomere length and organismal sensitivity to ionizing radiation (IR) in mammals. In particular, fifth generation (G5) mouse telomerase RNA (mTR)(-/)- mice, with telomeres 40% shorter than in wild-type mice, are hypersensitive to cumulative doses of gamma rays. 60% of the irradiated G5 mTR(-/)- mice die of acute radiation toxicity in the gastrointestinal tract...

Phosphorylation of p53 modifies sensitivity to ionizing radiation.

Phosphorylation is an important modification involved in the control of p53 activity. We examined the relationship between p53 phosphorylation and cell radiosensitivity. We prepared H1299 cells (p53-null) with various mutations of p53 at three sites (serine 15, 20 and 46) and examined the radiosensitivity of the cells. In three mutant forms of p53--S15A, S20A and S46A--serine was converted to a...

HIV-TAT mediated protein transduction of Cu/Zn-superoxide dismutase-1 (SOD1) protects skin cells from ionizing radiation

BACKGROUND Radiation-induced skin injury remains a serious concern during radiotherapy. Cu/Zn-superoxide dismutase (Cu/Zn-SOD, SOD1) is a conserved enzyme for scavenging superoxide radical in cells. Because of the integrity of cell membranes, exogenous molecule is not able to be incorporated into cells, which limited the application of natural SOD1. The aim of this study was to evaluate the pro...