Zinc supplementation of young men alters metallothionein, zinc transporter, and cytokine gene expression in leukocyte populations
Zinc supplementation of young men alters metallothionein, zinc transporter, and cytokine gene expression in leukocyte populations
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DOI：
10.1073/pnas.0510407103
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发表时间：
2006-02-07
影响因子：
11.1
通讯作者：
Cousins, RJ
中科院分区：
文献类型：
--
作者：
Aydemir, TB;Blanchard, RK;Cousins, RJ
与铁相比，评估人类锌状况的有效措施仍然难以捉摸，铁有许多代谢/功能指标。使用单核细胞，T淋巴细胞，和粒细胞分离的磁分选和干血斑（DBS）来自50 μ l的外周血，我们评估了金属硫蛋白（MT），锌转运蛋白和细胞因子基因的反应，以适度（15毫克的锌每天）的饮食锌补充剂在人类受试者。通过定量实时RT-PCR（QRT-PCR）测量转录物丰度。锌补充增加MT mRNA丰度高达2倍的RNA从白细胞亚群，和4倍的RNA从DBS。锌转运蛋白基因ZnT 1和Zip 3的转录水平增加和减少，分别通过补锌。白细胞亚群中ZnT 1和Zip基因的表达差异高达270倍。来自补充受试者的单核细胞和粒细胞被LIPS激活，而T淋巴细胞通过模拟抗原呈递被激活。随着锌的消耗，活化的单核细胞和粒细胞中TNF-α和IL-1 β的表达更高，活化的T淋巴细胞中IFN-γ mRNA水平更高。这些研究表明，QRT-PCR是一种可靠地测量人类受试者中营养响应基因转录本丰度的工具，并且当适当收集时，少量全血干样本可用作QRT-PCR分析的总RNA来源。所获得的结果还显示，人类受试者的锌补充编程特定的白细胞亚群，以在被免疫刺激物激活后显示增强的细胞因子表达。
An effective measure to assess zinc status of humans has remained elusive, in contrast to iron, where a number of indicators of metabolism/function are available. Using monocytes, T lymphocytes, and granulocytes isolated by magnetic sorting and dried blood spots (DBS) derived from 50 mu l of peripheral blood, we evaluated the response of metallothionein (MT), zinc transporter, and cytokine genes to a modest (15 mg of Zn per day) dietary zinc supplement in human subjects. Transcript abundance was measured by quantitative real-time RT-PCR (QRT-PCR). Zinc supplementation increased MT mRNA abundance by up to 2-fold in RNA from leukocyte subsets, and 4-fold in RNA from DBS. Transcript levels for the zinc transporter genes ZnT1 and Zip3 were increased and decreased, respectively, by zinc supplementation. Expression of the ZnT1 and Zip genes among leukocyte subsets differ by up to 270-fold. Monocytes and granulocytes from supplemented subjects were activated by LIPS, whereas T lymphocytes were activated by mimicking antigen presentation. With zinc consumption, TNF-alpha and IL-1 beta expression was greater in activated monocytes and granulocytes, and IFN-gamma mRNA levels were higher in activated T lymphocytes. These studies show that QRT-PCR is a tool to reliably measure transcript abundance for nutritionally responsive genes in human subjects, and that a small sample of whole dried blood, when appropriately collected, can be used as the source of total RNA for QRT-PCR analysis. The results obtained also show that zinc supplementation of human subjects programs specific leukocytic subsets to show enhanced cytokine expression upon activation by stimulators of immunity.