Modification of glycolysis affects cell sensitivity to apoptosis induced by oxidative stress and mediated by mitochondria.
The effect of alteration of the glycolytic pathway on cell damage induced by oxidative stress was investigated with dihydrofolate reductase-deficient Chinese hamster ovary (CHO) cells that either overexpress cytosolic glycerol-3-phosphate dehydrogenase (CHO/cGPDH cells) or are depleted of the A subunit of lactate dehydrogenase as a result of anti-sense RNA expression (CHO/anti-LDH cells). The extent of oxidative phosphorylation in CHO/anti-LDH and CHO/cGPDH cells was increased and decreased, respectively, relative to that in parental CHO cells, as revealed by measurement of the intracellular content of ATP, the rate of cellular O(2) consumption, the mitochondrial membrane potential (DeltaPsi(m)), and the generation of reactive oxygen species. The sensitivity of these cell lines to cell death induced by the exogenous oxidant tert-butyl hydroperoxide decreased according to the rank order CHO/anti-LDH>CHO>CHO/cGPDH. Exogenous pyruvate markedly increased the sensitivity of CHO/cGPDH cells to oxidant-induced death. The differences among the three cell lines in susceptibility to oxidant-induced death were reflected in the proportion of oxidant-treated cells with a subdiploid DNA content, with a collapsed DeltaPsi(m), and with cytochrome c in the cytosol, indicating that death was mediated by apoptosis. These results demonstrate that the influx of respiratory substrate into mitochondria is an important determinant of cell sensitivity to oxidant-induced apoptosis.
Jeong
Dae-won
DW
BK21 Human Life Sciences, Seoul National University, Seoul, Republic of Korea.
Kim
Tae-Soo
TS
Cho
Il Taeg
IT
Kim
Ick Young
IY
D000818:Animals; D017209:Apoptosis; D016466:CHO Cells; D006224:Cricetinae; D005993:Glycerolphosphate Dehydrogenase / Q000235:genetics; D006019:Glycolysis; D066298:In Vitro Techniques; D007770:L-Lactate Dehydrogenase / Q000172:deficiency / Q000235:genetics; D008928:Mitochondria / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D018384:Oxidative Stress; D016372:RNA, Antisense / Q000235:genetics; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D013762:Tetrahydrofolate Dehydrogenase / Q000172:deficiency / Q000235:genetics; D020122:tert-Butylhydroperoxide / Q000378:metabolism
D016372:RNA, Antisense; D017382:Reactive Oxygen Species; D020122:tert-Butylhydroperoxide; D005993:Glycerolphosphate Dehydrogenase; D007770:L-Lactate Dehydrogenase; D013762:Tetrahydrofolate Dehydrogenase