PT  - JOURNAL ARTICLE
AU  - Jason M. Hansen
AU  - Katie K. Harris
AU  - Martin A. Philbert
AU  - Craig Harris
TI  - Thalidomide Modulates Nuclear Redox Status and Preferentially Depletes Glutathione in Rabbit Limb versus Rat Limb
AID  - 10.1124/jpet.300.3.768
DP  - 2002 Mar 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 768--776
VI  - 300
IP  - 3
4099  - http://jpet.aspetjournals.org/content/300/3/768.short
4100  - http://jpet.aspetjournals.org/content/300/3/768.full
SO  - J Pharmacol Exp Ther2002 Mar 01; 300
AB  - Thalidomide produces numerous birth defects, the most notable being phocomelia. Mechanisms behind thalidomide-induced malformations have not been fully elucidated, although recent evidence suggests a role for reactive oxygen species. A thalidomide-resistant (rat) and -sensitive (rabbit) species were used to compare potential inherent differences related to oxidative stress that may provide a more definitive understanding of mechanisms of thalidomide embryopathy. Limb bud cells (LBCs) were removed from the rat and rabbit embryo, dissociated, and plated in culture for 24 h. A fluorescence (6-carboxy-2′,7′-dichlorofluorescin diacetate; DCF) assay for oxidative stress was used with varying concentrations of thalidomide (5–100 μM). Thalidomide (100 μM) showed a 6-fold greater production of oxidative stress in rabbit cultures than in rat. Lower concentrations (50 and 25 μM) also showed a significant increase in reactive oxygen species. Confocal microscopy revealed DCF fluorescence preferentially in rabbit LBC nuclei compared with the uniform distribution of DCF fluorescence in rat LBC. Localization of glutathione (GSH) was determined using 5-chloromethylfluorescein diacetate fluorescent confocal microscopy. In rat cultures, significant thalidomide-induced GSH depletion was detected in the cytosol but the nuclei maintained its GSH content, but rabbit LBC showed significant GSH depletion in both compartments. GSH depletion was confirmed by high-performance liquid chromatography analysis. These observations provide evidence that thalidomide preferentially produces oxidative stress in the thalidomide-sensitive species but not the thalidomide-resistant species. Nuclear GSH content in the rabbit LBC is selectively modified and indicates a shift in the nuclear redox environment. Redox shifts in the nucleus may result in the misregulation of transcription factor/DNA interactions and cause defective growth and development. The American Society for Pharmacology and Experimental Therapeutics