Hennigar Stephen R, Kelley Alyssa M, McClung James P
US Army Research Institute of Environmental Medicine, Military Nutrition Division, Natick, MA.
US Army Research Institute of Environmental Medicine, Military Nutrition Division, Natick, MA
Adv Nutr. 2016 Jul 15;7(4):735-46. doi: 10.3945/an.116.012518. Print 2016 Jul.
Zinc is an essential nutrient for humans; however, a sensitive biomarker to assess zinc status has not been identified. The objective of this systematic review was to compile and assess studies that determined zinc transporter and/or metallothionein expression in various blood cell types and to determine their reliability and sensitivity to changes in dietary zinc. Sixteen studies were identified that determined the expression of zrt-, irt-like protein (ZIP) 1 [solute carrier family (SLC) 39A1], ZIP3 (SLC39A3), ZIP5 (SLC39A5), ZIP6 (SLC39A6), ZIP7 (SLC39A7), ZIP8 (SLC39A8), ZIP10 (SLC39A10), ZIP14 (SLC39A14), zinc transporter (ZnT)1 (SLC30A1), ZnT2 (SLC30A2), ZnT4 (SLC30A4), ZnT5 (SLC30A5), ZnT6 (SLC30A6), ZnT7 (SLC30A7), ZnT9 (SLC30A9), and/or metallothionein in various blood cells isolated from healthy adult men and women in response to zinc supplementation or depletion. Cell types included leukocytes, peripheral blood mononuclear cells, T lymphocytes, monocytes, and erythrocytes. ZIP1, ZnT1, and metallothionein were the most commonly measured proteins. Changes in ZIP1 and ZnT1 in response to zinc supplementation or depletion were not consistent across studies. Leukocyte metallothionein decreased with zinc depletion (-39% change from baseline, <5 mg Zn/d, n = 2 studies) and increased with zinc supplementation in a dose-dependent manner (35%, 15-22 mg Zn/d, n = 7 studies; 267%, 50 mg Zn/d, n = 2 studies) and at the earliest time points measured; however, no change or delayed response was observed in metallothionein in erythrocytes. A greater percentage of studies demonstrated that metallothionein in leukocyte subtypes was a more reliable (100%, n = 12; 69%, n = 16) and responsive (92%, n = 12; 82%, n = 11) indicator of zinc exposure than was plasma zinc, respectively. In conclusion, current evidence indicates that metallothionein in leukocyte subtypes may be a component in determining zinc status.
锌是人体必需的营养素；然而，尚未确定一种用于评估锌状态的敏感生物标志物。本系统评价的目的是汇总和评估确定锌转运蛋白和/或金属硫蛋白在各种血细胞类型中的表达的研究，并确定它们对膳食锌变化的可靠性和敏感性。共确定了16项研究，这些研究确定了锌调控转运蛋白、铁调控转运蛋白样蛋白（ZIP）1[溶质载体家族（SLC）39A1]、ZIP3（SLC39A3）、ZIP5（SLC39A5）、ZIP6（SLC39A6）、ZIP7（SLC39A7）、ZIP8（SLC39A8）、ZIP10（SLC39A10）、ZIP14（SLC39A14）、锌转运蛋白（ZnT）1（SLC30A1）、ZnT2（SLC30A2）、ZnT4（SLC30A4）、ZnT5（SLC30A5）、ZnT6（SLC30A6）、ZnT7（SLC30A7）、ZnT9（SLC30A9）和/或金属硫蛋白在从健康成年男性和女性中分离出的各种血细胞中对锌补充或锌缺乏的反应。细胞类型包括白细胞、外周血单核细胞、T淋巴细胞、单核细胞和红细胞。ZIP1、ZnT1和金属硫蛋白是最常检测的蛋白质。不同研究中，ZIP1和ZnT1对锌补充或锌缺乏的反应不一致。锌缺乏时白细胞金属硫蛋白减少（与基线相比变化-39%，锌摄入量<5mg/d，2项研究），锌补充时白细胞金属硫蛋白以剂量依赖方式增加（35%，锌摄入量15 - 22mg/d，7项研究；267%，锌摄入量50mg/d，2项研究），且在最早测量时间点出现变化；然而，红细胞中的金属硫蛋白未观察到变化或延迟反应。更大比例的研究表明，白细胞亚群中的金属硫蛋白分别比血浆锌更可靠（100%，12项研究；69%，16项研究）和更能反映锌暴露情况（92%，12项研究；82%，11项研究）。总之，目前的证据表明白细胞亚群中的金属硫蛋白可能是确定锌状态的一个组成部分。
