Han Hyungchul, Archibeque Shawn L, Engle Terry E
Department of Animal Sciences, Colorado State University, Fort Collins, CO 80523-1171, USA.
Biol Trace Elem Res. 2009 Summer;129(1-3):130-6. doi: 10.1007/s12011-008-8293-6. Epub 2008 Dec 20.
Copper is an essential trace mineral required for growth and development. Copper homeostasis within the cell is mediated by the expression of the Cu transporter protein (CTR1), ATPase7A (ATP7A), ATPase7B (ATP7B), Cox17, and Cu chaperone for Cu-Zn superoxide dismutase (CCS) which helps to regulate Cu uptake, export, and intracellular compartmentalization in non-ruminants. Copper also serves as a cofactor of antioxidant, superoxide dismutase1 (SOD1). Liver tissue from eighteen Holstein bull calves (average BW 201 +/- 58.5 kg, 7.3 +/- 1.9 months) from a previous experiment were utilized to characterize and identify hepatic mRNA related to Cu metabolism and homeostasis in cattle. Hepatic Cu concentration was determined via flame atomic absorption, and total RNA was extracted using TRI reagent and purified using RNeasy. Hepatic Cu concentrations ranged from 86 to 801 mg of Cu/kg DM. Real-time polymerase chain reaction analysis revealed that CTR1, ATP7A, and ATP7B mRNA expressions were negatively correlated with hepatic Cu concentration, while CCS (P = 0.0887) and SOD1 had a tendency (P = 0.0733) to be negatively correlated to hepatic Cu concentration. These data indicate that higher than normal hepatic Cu concentration downregulates gene expression of CTR1, ATP7A, ATP7B, and Cox17, which are involved in bovine liver copper homeostasis.
铜是生长发育所必需的微量矿物质。细胞内的铜稳态由铜转运蛋白（CTR1）、ATP酶7A（ATP7A）、ATP酶7B（ATP7B）、Cox17以及铜锌超氧化物歧化酶（CCS）的铜伴侣蛋白的表达介导，这些蛋白有助于调节非反刍动物的铜摄取、输出和细胞内分隔。铜还作为抗氧化剂超氧化物歧化酶1（SOD1）的辅助因子。利用先前一项实验中18头荷斯坦公牛犊牛（平均体重201±58.5千克，7.3±1.9月龄）的肝脏组织来表征和鉴定与牛铜代谢和稳态相关的肝脏mRNA。通过火焰原子吸收法测定肝脏铜浓度，使用TRI试剂提取总RNA并使用RNeasy进行纯化。肝脏铜浓度范围为每千克干物质86至801毫克铜。实时聚合酶链反应分析表明，CTR1、ATP7A和ATP7B的mRNA表达与肝脏铜浓度呈负相关，而CCS（P = 0.0887）和SOD1有与肝脏铜浓度呈负相关的趋势（P = 0.0733）。这些数据表明，高于正常水平的肝脏铜浓度会下调参与牛肝脏铜稳态的CTR1、ATP7A、ATP7B和Cox17的基因表达。
