Oxidative stress-induced apoptosis prevented by Trolox.
The ability of oxidative stress to induce apoptosis (programmed cell death), and the effect of Trolox, a water soluble vitamin E analog, on this induction were studied in vitro in mouse thymocytes. Cells were exposed to oxidative stress by treating them with 0.5-10 microM hydrogen peroxide (H2O2) for 10 min, in phosphate-buffered saline supplemented with 0.1 mM ferrous sulfate. Cells were resuspended in RPMI 1640 medium with 10% serum and incubated at 37 degrees C under 5% CO2 in air. Electron microscopic studies revealed morphological changes characteristic of apoptosis in H2O2-treated cells. H2O2 treatment fragmented the DNA in a manner typical of apoptotic cells, producing a ladder pattern of 200 base pair increments upon agarose gel electrophoresis. The percentage of DNA fragmentation (determined fluorometrically) increased with increasing doses of H2O2 and postexposure incubation times. Pre- or posttreatment of cells with Trolox reduced H2O2-induced DNA fragmentation to control levels and below. The results indicate that oxidative stress induces apoptosis in thymocytes, and this induction can be prevented by Trolox, a powerful inhibitor of membrane damage.
Forrest
V J
VJ
Naval Medical Research Institute, Bethesda, MD.
Kang
Y H
YH
McClain
D E
DE
Robinson
D H
DH
Ramakrishnan
N
N
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002478:Cells, Cultured; D002839:Chromans / Q000494:pharmacology*; D004247:DNA / Q000187:drug effects / Q000302:isolation & purification; D004249:DNA Damage; D006861:Hydrogen Peroxide / Q000037:antagonists & inhibitors / Q000633:toxicity*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008854:Microscopy, Electron; D013950:Thymus Gland / Q000166:cytology* / Q000187:drug effects / Q000648:ultrastructure
D000975:Antioxidants; D002839:Chromans; D004247:DNA; D006861:Hydrogen Peroxide; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid