Effects of Ascorbic Acid Deficiency on Protein and Lipid Oxidation in Livers from SMP30/GNL Knockout Mice
Effects of Ascorbic Acid Deficiency on Protein and Lipid Oxidation in Livers from SMP30/GNL Knockout Mice
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DOI：
10.3177/jnsv.59.489
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发表时间：
2013-12-01
影响因子：
1.6
通讯作者：
Ishigami, Akihito
中科院分区：
文献类型：
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作者：
Amano, Akiko;Sato, Yasunori;Ishigami, Akihito
抗坏血酸（AA）作为电子供体，在体外清除活性氧，如超氧化物、单线态氧和羟基自由基。然而，很少有人知道AA缺乏对肝脏中蛋白质和脂质氧化水平的影响。因此，我们测量了衰老标记蛋白-30（SMP 30）/β-内酯酶（GNL）敲除（KO）小鼠肝脏中蛋白质羰基和硫代巴比妥酸反应物质（TBARS）的水平。这些小鼠缺乏AA，因为它们缺乏SMP 30/GNL基因，这是体内AA生物合成所必需的。为了追踪AA缺乏的影响，在30日龄时，将小鼠分为以下四组：AA（-）SMP 30/GNL KO、AA（+）SMP 30/GNL KO、AA（-）野生型（WT）和AA（+）WT。AA（+）组给予含1.5g/L AA的水，AA（-）组给予不含AA的水，共57 d。所有小鼠均喂食不含AA的饲料。随后，AA（-）SMP 30/GNL KO小鼠肝脏中的蛋白质羰基水平显著高于其他三组;然而，TBARS水平在四组之间没有显著差异。因此，AA必须作为蛋白质的抗氧化剂，但可能不会直接保护肝脏中的脂质氧化。
Ascorbic acid (AA) functions as an electron donor and scavenges reactive oxygen species such as superoxide, singlet oxygen, and hydroxyl radicals in vitro. However, little is known about the effect of an AA deficiency on protein and lipid oxidation levels in the liver. Therefore, we measured the levels of protein carbonyl and thiobarbituric acid reactive substances (TBARS) in livers from senescence marker protein-30 (SMP30)/gluconolactonase (GNL) knockout (KO) mice. These mice are deficient in AA, because they lack the SMP30/GNL gene, which is essential for the biosynthesis of AA in vivo. To track the effect of an AA deficiency, at 30 d of age, mice were divided into the following four groups: AA (-) SMP30/GNL KO, AA (+) SMP30/GNL KO, AA (-) wild type (WT), and AA (+) WT. The AA (+) groups were given water containing 1.5 g/L AA, whereas the AA (-) groups received water without AA for 57 d. All mice were fed an AA-free diet. Subsequently, protein carbonyl levels in livers from AA (-) SMP30/GNL KO mice were significantly higher than those from the other three groups; however, TBARS levels were not significantly different among the four groups. Therefore, AA must act as an anti-oxidant for proteins but might not directly protect lipid oxidation in the liver.