Fico Annalisa, Manganelli Genesia, Cigliano Luisa, Bergamo Paolo, Abrescia Paolo, Franceschi Claudio, Martini Giuseppe, Filosa Stefania
Institute of Genetics and Biophysics Adriano Buzzati Traverso, CNR, Via Pietro Castellino 111, 80131 Napoli, Italy.
Free Radic Biol Med. 2008 Jul 15;45(2):211-7. doi: 10.1016/j.freeradbiomed.2008.04.017. Epub 2008 Apr 23.
Oxidative stress is caused by imbalance between the production of reactive oxygen species (ROS) and biological system ability to readily detoxify the reactive intermediates or repair the resulting damage. 2-deoxy-D-ribose (dRib) is known to induce apoptosis by provoking an oxidative stress by depleting glutathione (GSH). In this paper, we elucidate the mechanisms underlying GSH depletion in response to dRib treatment. We demonstrated that the observed GSH depletion is not only due to inhibition of synthesis, by inhibiting gamma-glutamyl-cysteine synthetase, but also due to its increased efflux, by the activity of multidrug resistance associated proteins transporters. We conclude that dRib interferes with GSH homeostasis and that likely cellular oxidative stress is a consequence of GSH depletion. Various GSH fates, such as direct oxidation, lack of synthesis or of storage, characterize different kinds of oxidative stress. In the light of our observations we conclude that dRib does not induce GSH oxidation but interferes with GSH synthesis and storage. Lack of GSH allows accumulation of ROS and cells, disarmed against oxidative insults, undergo apoptosis.
氧化应激是由活性氧(ROS)产生与生物系统快速解毒反应性中间体或修复由此产生损伤的能力之间的失衡所引起的。已知2-脱氧-D-核糖(dRib)通过消耗谷胱甘肽(GSH)引发氧化应激来诱导细胞凋亡。在本文中,我们阐明了响应dRib处理时GSH消耗的潜在机制。我们证明,观察到的GSH消耗不仅是由于通过抑制γ-谷氨酰半胱氨酸合成酶而抑制了其合成,还由于多药耐药相关蛋白转运体的活性导致其外排增加。我们得出结论,dRib干扰了GSH的动态平衡,并且细胞氧化应激可能是GSH消耗的结果。各种GSH的命运,如直接氧化、合成或储存不足,是不同类型氧化应激的特征。根据我们的观察结果,我们得出结论,dRib不会诱导GSH氧化,但会干扰GSH的合成和储存。GSH的缺乏会使ROS积累,而失去抗氧化损伤能力的细胞会发生凋亡。