15677696

pubmed:Citation

6

Dorsal root ganglia neurons in culture die through programmed cell death when exposed to elevated glucose, providing an in vitro model system for the investigation of the mechanisms leading to diabetic neuropathy. This study examines the time course of programmed cell death induction, regulation of cellular antioxidant capacity, and the protective effects of antioxidants in neurons exposed to hyperglycemia. We demonstrate that the first 2 h of hyperglycemia are sufficient to induce oxidative stress and programmed cell death. Using fluorimetric analysis of reactive oxygen species (ROS) production, in vitro assays of antioxidant enzymes, and immunocytochemical assays of cell death, we demonstrate superoxide formation, inhibition of aconitase, and lipid peroxidation within 1 h of hyperglycemia. These are followed by caspase-3 activation and DNA fragmentation. Antioxidant potential increases by 3-6 h but is insufficient to protect these neurons. Application of the antioxidant alpha-lipoic acid potently prevents glucose-induced oxidative stress and cell death. This study identifies cellular therapeutic targets to prevent diabetic neuropathy. Since oxidative stress is a common feature of the micro- and macrovascular complications of diabetes, the present findings have broad application to the treatment of diabetic patients.

eng

IM

MEDLINE

1530-6860

Electronic

NLM

638-40

pubmed-meshheading:15677696-Aconitate Hydratase, pubmed-meshheading:15677696-Animals, pubmed-meshheading:15677696-Antioxidants, pubmed-meshheading:15677696-Apoptosis, pubmed-meshheading:15677696-Caspase 3, pubmed-meshheading:15677696-Caspases, pubmed-meshheading:15677696-Catalase, pubmed-meshheading:15677696-Cells, Cultured, pubmed-meshheading:15677696-DNA Fragmentation, pubmed-meshheading:15677696-Enzyme Activation, pubmed-meshheading:15677696-Ganglia, Spinal, pubmed-meshheading:15677696-Glucose, pubmed-meshheading:15677696-Glutathione, pubmed-meshheading:15677696-Hyperglycemia, pubmed-meshheading:15677696-Lipid Peroxidation, pubmed-meshheading:15677696-Multienzyme Complexes, pubmed-meshheading:15677696-NADH, NADPH Oxidoreductases, pubmed-meshheading:15677696-Neurons, pubmed-meshheading:15677696-Oxidative Stress, pubmed-meshheading:15677696-Rats, pubmed-meshheading:15677696-Rats, Sprague-Dawley, pubmed-meshheading:15677696-Superoxide Dismutase, pubmed-meshheading:15677696-Superoxides, pubmed-meshheading:15677696-Thiobarbituric Acid Reactive Substances, pubmed-meshheading:15677696-Thioctic Acid, pubmed-meshheading:15677696-Time Factors

Short-term hyperglycemia produces oxidative damage and apoptosis in neurons.

Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural