Protein and DNA oxidation in spinal injury: neurofilaments--an oxidation target.

Abstract

This study measured the time courses of protein and DNA oxidation following spinal cord injury (SCI) in rats and characterized oxidative degradation of proteins. Protein carbonyl content-a marker of protein oxidation-significantly increased at 3-9 h postinjury and the ratio 8-hydroxy-2-deoxyguanosine/deoxyguanosine-an indicator of DNA oxidation-was significantly higher at 3-6 h postinjury in the injured cords than in the sham controls. This suggests that oxidative modification of proteins and DNA contributes to secondary damage in SCI. Densities of selected bands on coomassie-stained gels indicated that most proteins were degraded. Neurofilament protein (NFP) was particularly evaluated immunohistochemically; its light chain (NFP-68) was gradually degraded in nerve fibers, neuron bodies, and large dendrites following SCI. A mixture of Mn (III) tetrakis (4-benzoic acid) porphyrin (10 mg/kg)-a novel SOD mimetic-and nitro-L-arginine (1 mg/kg)-an inhibitor of nitric oxide synthase-injected intraperitoneally, increased NFP-68 immunoreactivity and the numbers of NFP-positive nerve fibers post-SCI, correlating NFP degradation in SCI to free radical-triggered oxidative damage for the first time. Therefore, blockage of protein and DNA oxidation in the secondary injury stage may improve long-term recovery-important information for development of the SCI therapies.

• Authors: M L Leski, F Bao, L Wu, H Qian, D Sun, D Liu
• Journal: Free radical biology & medicine (Free Radic Biol Med) Vol. 30 Issue 6 Pg. 613-24 (Mar 15 2001) ISSN: 0891-5849 [Print] United States
• PMID: 11295359 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Free Radical Scavengers
• Metalloporphyrins
• Neurofilament Proteins
• Proteins
• manganese(III)-tetrakis(4-benzoic acid)porphyrin
• neurofilament protein NF 68
• Nitroarginine
• 8-Hydroxy-2'-Deoxyguanosine
• DNA
• Deoxyguanosine

Topics

• 8-Hydroxy-2'-Deoxyguanosine
• Animals
• Chromatography, High Pressure Liquid
• DNA (metabolism)
• Deoxyguanosine (analogs & derivatives, metabolism)
• Free Radical Scavengers (pharmacology, therapeutic use)
• Immunohistochemistry
• Male
• Metalloporphyrins (pharmacology, therapeutic use)
• Neurofibrils (chemistry, drug effects, metabolism, pathology)
• Neurofilament Proteins (metabolism)
• Neurons (drug effects, metabolism, pathology)
• Nitroarginine (pharmacology, therapeutic use)
• Oxidation-Reduction (drug effects)
• Proteins (metabolism)
• Rats
• Rats, Sprague-Dawley
• Spinal Injuries (drug therapy, metabolism, pathology)