Reduced neurotoxicity in transgenic mice overexpressing human copper-zinc-superoxide dismutase.
The role of oxygen-derived free radicals, superoxide in particular, in the pathogenesis of neuronal cell death induced by glutamate was studied using cultured cortical neurons from transgenic mice overexpressing human copper-zinc-superoxide dismutase. Primary cortical neuron cultures were developed from 15-day-old fetuses of both transgenic mice and their normal littermates. Both human copper-zinc-superoxide dismutase and host mouse copper-zinc-superoxide dismutase activities in cultured neurons were identified by native gel electrophoresis followed by nitroblue tetrazolium staining. Cultured neurons grown for 10-12 days in vitro were exposed briefly to 0.5 mM glutamate for 5 minutes, followed by biochemical and morphological examinations at 2, 4, and 24 hours. Our data have demonstrated that glutamate neurotoxicity is significantly reduced in transgenic neurons at 2 and 4 hours following exposure to glutamate, as measured by the efflux of lactate dehydrogenase, the 3-O-methyl glucose space, and by phase-contrast and bright-field trypan blue staining. These data indicate that transgenic neurons containing twofold to threefold the normal amount of copper-zinc-superoxide dismutase activity as the result of expression of the human copper-zinc-superoxide dismutase transgene are protected against glutamate neurotoxicity in vitro. Our results suggest that oxidative stress, at least in part, plays an important role in the biochemical pathways amplifying N-methyl-D-aspartate receptor-mediated neurotoxicity.
Chan
P H
PH
Department of Neurosurgery, University of California, School of Medicine, San Francisco 94143.
Chu
L
L
Chen
S F
SF
Carlson
E J
EJ
Epstein
C J
CJ
D000818:Animals; D002470:Cell Survival; D003300:Copper / Q000378:metabolism*; D015870:Gene Expression; D005971:Glutamates / Q000494:pharmacology / Q000633:toxicity*; D051379:Mice; D008822:Mice, Transgenic; D009420:Nervous System / Q000187:drug effects*; D009474:Neurons / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism* / Q000502:physiology; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
D005971:Glutamates; D003300:Copper; D013482:Superoxide Dismutase; D015032:Zinc