A newly established neuronal rho-0 cell line highly susceptible to oxidative stress accumulates iron and other metals. Relevance to the origin of metal ion deposits in brains with neurodegenerative disorders.
From human neuroblastoma-derived SILA cells we have established a rho-0 cell line that is deficient in both respiration and mitochondrial DNA. Lactate dehydrogenase activity, lactate production, and growth in the medium without glucose indicate that these cells shift from aerobic to anaerobic metabolism. Electron microscopic observations revealed abnormal mitochondria with unique cristae structures. Staining with MitoTracker dye showed that the mitochondrial transmembrane potential was reduced by 30-40% from the parent cell levels. These cells were markedly susceptible to H(2)O(2) and died apparently by a necrotic mechanism, a process blocked by deferoxamine in the parent cells but not rho-0 cells. Analysis by inductively coupled plasma-mass spectrometry revealed an approximately 3-fold accumulation of iron in the rho-0 cells at confluence (n = 4-6, three clones, *p < 0.05). Iron and four other metals were all elevated in the cells of one of the rho-0 clones and were similar to control levels in the control cybrid cells, which were replenished with normal mitochondrial DNA. Their sensitivity to H(2)O(2) was also similar to that of the parent cells. These results indicate that a newly established neuronal related rho-0 cell line is highly susceptible to active oxygen species and that these toxicity effects appear to be related to an accumulation of transition metals, which probably occurs through the respiratory impairment.
Department of Pathology and Applied Neurobiology, Research Institute for Neurological Diseases and Geriatrics, Kyoto Prefectural University of Medicine, 465 Kawaramachi Hirokoji, Kamigyo-ku, Japan. rxf33@po.cwru.edu
Ryuichi
R
Fukuyama
Akihiko
A
Nakayama
Taizen
T
Nakase
Hiroe
H
Toba
Teruo
T
Mukainaka
Hirofumi
H
Sakaguchi
Takuya
T
Saiwaki
Hiromu
H
Sakurai
Mikio
M
Wada
Shinji
S
Fushiki
D001921:Brain / Q000378:metabolism*; D019069:Cell Respiration; D003300:Copper / Q000378:metabolism; D006019:Glycolysis; D006801:Humans; D006861:Hydrogen Peroxide / Q000633:toxicity; D007501:Iron / Q000378:metabolism*; D008564:Membrane Potentials; D008854:Microscopy, Electron; D008928:Mitochondria / Q000502:physiology; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology / Q000648:ultrastructure; D019636:Neurodegenerative Diseases / Q000378:metabolism*; D018384:Oxidative Stress; D019289:Pyruvic Acid / Q000378:metabolism; D014407:Tumor Cells, Cultured; D014529:Uridine / Q000378:metabolism
D003300:Copper; D019289:Pyruvic Acid; D006861:Hydrogen Peroxide; D007501:Iron; D014529:Uridine