USDA Agricultural Research Service Grand Forks Human Nutrition Research Center, Grand Forks, ND 58203, USA.
Nutrients. 2017 Oct 19;9(10):1145. doi: 10.3390/nu9101145.
Metallothioneins (MTs) perform important regulatory and cytoprotective functions in tissues including the brain. While it is known that energy restriction (ER) and dietary -3 polyunsaturated fatty acid (PUFA) deficiency impact postnatal brain growth and development, little data exist regarding the impact of undernutrition upon MT expression in growing animals. We tested the hypothesis that ER with and without dietary -3 PUFA deficiency reduces MT expression in juvenile rats. ER rats were individually pair-fed at 75% of the ad libitum (AL) intake of control rats provided diets consisting of either soybean oil (SO) that is α-linolenic acid (ALA; 18:3-3) sufficient or corn oil (CO; ALA-deficient). Fatty acids (FA) and metal concentrations of liver and brain regions were analyzed. Tissue expression of MTs () and modulators of MT expression including glucocorticoid receptors ( and ) and several mediators of thyroid hormone regulation (, , , , and ) were measured. Plasma corticosterone and triiodothyronine levels were also evaluated. ER, but not metal deficiency, reduced expression in the cerebellum (50%) and cerebral cortex (23%). In liver, a reduction in dietary -3 PUFA reduced , , , , and . ER elevated , , and and reduced in the liver. Given MT's role in cellular protection, further studies are needed to evaluate whether ER or -3 PUFA deficiency may leave the juvenile brain and/or liver more susceptible to endogenous or environmental stressors.
金属硫蛋白（MTs）在包括大脑在内的组织中发挥着重要的调节和细胞保护作用。虽然人们知道能量限制（ER）和饮食中 -3 多不饱和脂肪酸（PUFA）缺乏会影响产后大脑的生长和发育，但关于营养不足对生长中的动物 MT 表达的影响的数据很少。我们检验了这样一个假设，即 ER 结合饮食中 -3 PUFA 缺乏会降低幼鼠的 MT 表达。ER 大鼠被单独进行 75%的限制喂养（AL），其饮食由含有足够 α-亚麻酸（ALA；18:3-3）的大豆油（SO）或缺乏 ALA 的玉米油（CO）组成。分析了肝脏和脑组织中 FA 和金属的浓度。测量了 MT 的组织表达（）和 MT 表达调节剂，包括糖皮质激素受体（和）以及几种甲状腺激素调节介质（、、、、和）。还评估了血浆皮质酮和三碘甲状腺原氨酸水平。ER，但不是金属缺乏，会降低小脑（50%）和大脑皮层（23%）中的表达。在肝脏中，-3 PUFA 的减少会降低、、、和。ER 会增加肝脏中的、、和，同时降低。鉴于 MT 在细胞保护中的作用，需要进一步研究来评估 ER 或 -3 PUFA 缺乏是否会使幼鼠的大脑和/或肝脏更容易受到内源性或环境应激源的影响。
