Al-Maghrebi May, Cojocel Constantin, Thompson Mary S
Department of Biochemistry, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait.
Mol Cell Biochem. 2005 May;273(1-2):177-83. doi: 10.1007/s11010-005-0552-7.
Translation elongation factor-1 (EF-1) forms a primary site of regulation of protein synthesis and has been implicated amongst others in tumorigenesis, diabetes and cell death. To investigate whether diabetes-induced oxidative stress affects EF-1 gene expression, we used a free radical scavenger, vitamin E. The following groups of rats (5/group) were studied: control, vitamin E control, diabetic and diabetic treated with vitamin E. Markers of hyperglycemia, kidney function, oxidative stress, and kidney hypertrophy were elevated in diabetic rats. Increased urinary protein excretion indicated early signs of glomerular and tubular dysfunction. The mRNA and protein levels of the three EF-1 subunits (A, Balpha, and Bgamma) were determined in renal cortex extracts using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), northern blot analysis and western blotting. EF-1A mRNA expression in renal cortex extracts was significantly increased by at least 2-fold (p < 0.002) in diabetic rats; however, there was no change in the mRNA levels of EF-1Balpha and EF-1Bgamma subunits. Similar results were observed at the protein level. Treatment of diabetic rats with vitamin E for 10 days suppressed both glycemic and oxidative stresses in renal cortex and kidney hypertrophy. EF-1A mRNA and protein levels were also reduced to control levels. In conclusion, EF-1A but not EF-1Balpha and EF-1Bgamma gene expression is significantly enhanced in the renal cortex of diabetic rats. Normalization of enhanced EF-1A expression by vitamin E treatment suggests a role for EF-1A during diabetes-induced oxidative stress.
翻译延伸因子-1（EF-1）构成了蛋白质合成调控的主要位点，并且在肿瘤发生、糖尿病和细胞死亡等过程中发挥了作用。为了研究糖尿病诱导的氧化应激是否影响EF-1基因表达，我们使用了一种自由基清除剂——维生素E。研究了以下几组大鼠（每组5只）：对照组、维生素E对照组、糖尿病组以及用维生素E治疗的糖尿病组。糖尿病大鼠的高血糖、肾功能、氧化应激和肾脏肥大标志物均升高。尿蛋白排泄增加表明肾小球和肾小管功能障碍的早期迹象。使用半定量逆转录聚合酶链反应（RT-PCR）、Northern印迹分析和Western印迹法测定肾皮质提取物中三种EF-1亚基（A、Bα和Bγ）的mRNA和蛋白质水平。糖尿病大鼠肾皮质提取物中EF-1A mRNA表达显著增加至少2倍（p<0.002）；然而，EF-1Bα和EF-1Bγ亚基的mRNA水平没有变化。在蛋白质水平也观察到了类似的结果。用维生素E治疗糖尿病大鼠10天可抑制肾皮质中的血糖和氧化应激以及肾脏肥大。EF-1A mRNA和蛋白质水平也降至对照水平。总之，糖尿病大鼠肾皮质中EF-1A基因表达显著增强，而EF-1Bα和EF-1Bγ基因表达未增强。维生素E治疗使增强的EF-1A表达恢复正常，这表明EF-1A在糖尿病诱导的氧化应激过程中发挥作用。
