Hruda Jan, Sramek Vladimir, Leverve Xavier
INSERM U Laboratoire de Bioenergetique Fondamentale et Apliquee, Universite J. Fourier, Grenoble, France.
Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2010 Dec;154(4):315-20. doi: 10.5507/bp.2010.047.
The study was carried out to evaluate the effect of several substrates on oxidative stress induced apoptosis and in K-562 cells.
Glucose at 5, 11 and 30 mM concentrations was tested, as well as 5 mM glutamine and 5 mM fructose. The cells were exposed to tert-butylhydroperoxide (tBH) and apoptotic cells were evaluated by flow cytometry with FITC-Annexin V and propidium iodide. The effect of glucose concentration on DNA damage was evaluated using hydrogen peroxide and electrophoretic "DNA comets" assay at 5 mM and 30 mM glucose concentrations.
The exposure of cells to tBH resulted in increased number of apoptotic cells, and this effect was prevented by administration of an antioxidant - N-Acetyl cysteine. Rising concentrations of glucose added to the toxic effect of tBH; we also observed some toxic effect of fructose and no effect of glutamine. We found higher susceptibility to hydrogen peroxide induced DNA damage with 30 mM glucose concentration.
Hyperglycemia increases the cell's susceptibility to oxidative stress and it also amplifies oxidative DNA damage. Glutamine - when used as a sole energetic substrate - showed no protective effect against oxidative stress.
本研究旨在评估几种底物对K-562细胞中氧化应激诱导的细胞凋亡的影响。
测试了浓度为5、11和30 mM的葡萄糖，以及5 mM谷氨酰胺和5 mM果糖。将细胞暴露于叔丁基过氧化氢（tBH），并用FITC-Annexin V和碘化丙啶通过流式细胞术评估凋亡细胞。在5 mM和30 mM葡萄糖浓度下，使用过氧化氢和电泳“DNA彗星”试验评估葡萄糖浓度对DNA损伤的影响。
细胞暴露于tBH导致凋亡细胞数量增加，而抗氧化剂N-乙酰半胱氨酸的给药可预防这种效应。葡萄糖浓度升高会增强tBH的毒性作用；我们还观察到果糖有一些毒性作用，而谷氨酰胺没有作用。我们发现30 mM葡萄糖浓度下细胞对过氧化氢诱导的DNA损伤更敏感。
高血糖会增加细胞对氧化应激的敏感性，还会加剧氧化性DNA损伤。谷氨酰胺——当用作唯一的能量底物时——对氧化应激没有保护作用。
