Mitochondrial oxygen consumption inhibition importance for TMT-dependent cell death in undifferentiated PC12 cells.
The evolving role of mitochondria as a target for different death-inducing noxae prompted us to investigate trimethyltin (TMT)-dependent effects on mitochondrial functionality. For this purpose, we used a homogeneous cell culture model represented by undifferentiated PC12 cells. Mitochondria isolated from PC12 cells treated with TMT for 6, 12 and 24h, showed a time-dependent inhibition of ADP-stimulated oxygen consumption using succinate or glutamate/malate as substrate. Using a fluorescent assay, the effect of TMT on mitochondrial membrane potential (delta Psi) in PC12 cells was also determined. After 24h in culture, a strong loss of mitochondrial membrane potential (delta Psi) was observed in TMT-treated cells. Collapse of mitochondrial membrane potential correlated with an increased expression of bax/bcl-2 ratio, as evaluated by polymerase chain reaction. Western blotting and spectrophotometric analysis showed that cytochrome c release and activation of caspase 3 were concurrently induced. Our findings suggest that inhibition of mitochondrial respiration represents the early toxic event for cell death in PC12 due to trimethyltin.
Misiti
Francesco
F
Department of Health and Motor Sciences, University of Cassino, Viale Bonomi, 03043 Cassino (FR), Italy. f.misiti@unicas.it <f.misiti@unicas.it>
Orsini
Federica
F
Clementi
M Elisabetta
ME
Lattanzi
Wanda
W
Giardina
Bruno
B
Michetti
Fabrizio
F
D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D053148:Caspase 3 / Q000187:drug effects / Q000378:metabolism; D019069:Cell Respiration / Q000187:drug effects / Q000502:physiology; D045304:Cytochromes c / Q000187:drug effects / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects / Q000502:physiology; D008928:Mitochondria / Q000187:drug effects* / Q000378:metabolism; D009410:Nerve Degeneration / Q000139:chemically induced* / Q000378:metabolism / Q000503:physiopathology; D009498:Neurotoxins / Q000633:toxicity; D010101:Oxygen Consumption / Q000187:drug effects* / Q000502:physiology; D016716:PC12 Cells; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D014298:Trimethyltin Compounds / Q000633:toxicity*; D051028:bcl-2-Associated X Protein / Q000187:drug effects / Q000378:metabolism
D009498:Neurotoxins; D019253:Proto-Oncogene Proteins c-bcl-2; D014298:Trimethyltin Compounds; D051028:bcl-2-Associated X Protein; C046488:trimethyltin; D045304:Cytochromes c; D053148:Caspase 3