Association Between DNA and RNA Oxidative Damage and Mortality of Patients with Traumatic Brain Injury
NEUROCRITICAL CARE
Authors: Lorente, Leonardo; Martin, Maria M.; Gonzalez-Rivero, Agustin F.; Perez-Cejas, Antonia; Abreu-Gonzalez, Pedro; Ramos, Luis; Argueso, Monica; Caceres, Juan J.; Sole-Violan, Jordi; Alvarez-Castillo, Andrea; Jimenez, Alejandro; Garcia-Marin, Victor
Abstract
Background The hyperoxidative state in traumatic brain injury (TBI) could produce oxidative damage on the ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Oxidative damage to nucleic acids in TBI patients has been studied, and higher concentrations of 8-OHdG were found in postmortem brain samples of subjects who died following TBI than in subjects who died from sudden cardiac death. Thus, the objective of this study was to determine whether there is an association between serum DNA and RNA oxidative damage and mortality in TBI patients. Methods We included patients with severe isolated TBI defined as a lower score than 9 points in the Glasgow Coma Scale (GCS) and lower than 9 points in non-cranial aspects in the Injury Severity Score. We determined serum concentrations of the three oxidized guanine species (OGS) (8-OHdG from DNA, 8-hydroxyguanosine from RNA, and 8-hydroxyguanine from DNA or RNA) and malondialdehyde (to estimate lipid peroxidation) on the day of TBI. Mortality at 30 days was the end-point study. Results We found higher serum concentrations of OGS (p < 0.001) and malondialdehyde (p < 0.001) in non-surviving (n = 34) than in surviving patients (n = 90), an association between serum OGS levels and 30-day mortality after control for CGS, age, and computed tomography findings (OR = 1.397; 95% CI = 1.137-1.716; p = 0.001), and a positive correlation between serum levels of OGS and malondialdehyde (rho = 0.24; p = 0.01). Conclusions To our knowledge, our study is the largest series reporting data on DNA oxidative damage in TBI patients and is the first reporting DNA and RNA oxidative damage in TBI patients associating lipid peroxidation and mortality.
Oxidative damage to RNA in neurodegenerative diseases
JOURNAL OF BIOMEDICINE AND BIOTECHNOLOGY
Authors: Nunomura, Akihiko; Honda, Kazuhiro; Takeda, Atsushi; Hirai, Keisuke; Zhu, Xiongwei; Smith, Mark A.; Perry, George
Abstract
Since 1999, oxidative damage to RNA molecules has been described in several neurological diseases including Alzheimer's disease, Parkinson's disease, Down syndrome, dementia with Lewy bodies, prion disease, subacute sclerosing panencephalitis, and xeroderma pigmentosum. An early involvement of RNA oxidation of vulnerable neuronal population in the neurodegenerative diseases has been demonstrated, which is strongly supported by a recent observation of increased RNA oxidation in brains of subjects with mild cognitive impairment. Until recently, little is known about consequences and cellular handling of the RNA damage. However, increasing body of evidence suggests detrimental effects of the RNA damage in protein synthesis and the existence of several coping mechanisms including direct repair and avoiding the incorporation of the damaged ribonucleotides into translational machinery. Further investigations toward understanding of the consequences and cellular handling mechanisms of the oxidative RNA damage may provide significant insights into the pathogenesis and therapeutic strategies of the neurodegenerative diseases. Copyright (c) 2006 Akihiko Nunomura et al.