High dietary intake of vitamin C suppresses age-related thymic atrophy and contributes to maintenance of immune cells in vitamin C-deficient SMP30 knockout mice.
High dietary intake of vitamin C suppresses age-related thymic atrophy and contributes to maintenance of immune cells in vitamin C-deficient SMP30 knockout mice.
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饮食中摄入大量维生素 C 可抑制与年龄相关的胸腺萎缩，并有助于维持维生素 C 缺乏的 SMP30 基因敲除小鼠的免疫细胞。
DOI：
10.1017/s0007114514003857
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
A.
中科院分区：
文献类型：
--
作者：
Uchio;R.;Hirose;Y.;Murosaki;S.;Yamamoto;Y.;Ishigami;A.
维生素 C (VC) 是人类和某些其他动物的必需营养素。它具有抗氧化特性，据报道可以改善脂质、DNA 和蛋白质的氧化损伤。然而，人们对于VC对免疫功能的影响却知之甚少，尤其是长期大剂量VC摄入对免疫细胞数量和功能的影响。在本研究中，为了评估 VC 的免疫效果，给 VC 缺陷型衰老标记蛋白 30 敲除 (SMP30KO) 小鼠喂食含有推荐水平 VC（每天 20 mg/kg；0·02% VC）或高水平 VC（每天 200 mg/kg；0·2% VC）的饮食，为期 1 年。喂养1年后，0·02 %组血浆VC浓度与同龄C57BL/6小鼠相同；然而，0·2 % VC 组的血浆 VC 浓度和胸腺重量显着高于 0·02 % VC 组。 0·2 % VC组外周血中白细胞、淋巴细胞、粒细胞和单核细胞总数以及脾细胞和胸腺细胞数均显着高于0·02 % VC组。此外，饮食治疗1年后，0·2 % VC组的外周血淋巴细胞中的幼稚T细胞数量、脾细胞中的记忆T细胞群数量以及胸腺细胞中的分化簇(CD)4+CD8+或CD4+CD8−或CD4−CD8+ T细胞数量均显着高于0·02 % VC组。这些结果表明，长期高剂量摄入 VC 可有效维持免疫细胞，部分是通过抑制 VC 缺乏的 SMP30KO 小鼠中与年龄相关的胸腺退化。
Vitamin C (VC) is an essential nutrient for humans and certain other animals. It has antioxidant properties and has been reported to ameliorate oxidative damage to lipids, DNA and proteins. However, the effects of VC on immune function are poorly understood, especially the influence of long-term high-dose VC intake on the number and function of immune cells. In the present study, to evaluate the immune effects of VC, VC-deficient senescence marker protein-30 knockout (SMP30KO) mice were fed a diet containing the recommended level of VC (20 mg/kg per d; 0·02 % VC) or a high level of VC (200 mg/kg per d; 0·2 % VC) for 1 year. The plasma VC concentration of the 0·02 % group was the same as that of age-matched C57BL/6 mice after 1 year of feeding; however, plasma VC concentration and thymus weight were significantly higher in the 0·2 % VC group than in the 0·02 % VC group. The total counts of leucocytes, lymphocytes, granulocytes and monocytes in the peripheral blood, as well as the number of splenocytes and thymocytes, were all significantly higher in the 0·2 % VC group than in the 0·02 % VC group. In addition, the number of naive T cells in peripheral blood lymphocytes, the number of memory T-cell populations in splenocytes, and the number of cluster of differentiation (CD)4+CD8+ or CD4+CD8− or CD4−CD8+ T cells in thymocytes were all markedly higher in the 0·2 % VC group than in the 0·02 % VC group after 1 year of dietary treatment. These results suggest that a long-term high-dose intake of VC is effective in the maintenance of immune cells, partly through the suppression of age-related thymic involution in VC-deficient SMP30KO mice.