cDNA array analysis identifies thymic LCK as upregulated in moderate murine zinc deficiency before T-lymphocyte population changes
cDNA array analysis identifies thymic LCK as upregulated in moderate murine zinc deficiency before T-lymphocyte population changes
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DOI：
10.1093/jn/131.12.3189
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发表时间：
2001-12-01
影响因子：
4.2
通讯作者：
Cousins, RJ
中科院分区：
文献类型：
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作者：
Moore, JB;Blanchard, RK;Cousins, RJ
严重缺锌对哺乳动物免疫系统胸腺和t淋巴细胞室的有害后遗症已经确定，但潜在的机制尚不清楚。假设锌缺乏期间观察到的t淋巴细胞数量和功能的改变可能是由基因表达的变化引起的，我们试图利用cDNA阵列比较锌缺乏和锌正常小鼠的胸腺mRNA表达谱。对于本文所描述的小鼠模型，3周的膳食锌缺乏并不会影响年轻成年远交种小鼠的食物摄入量或生长速度，但会显著降低锌状态的多个参数。此外，荧光活化细胞分选（FACS）分析显示，表达细胞表面标记CD3、CD4或CD8的胸腺细胞群没有变化，这表明观察到的mRNA丰度变化不是由于不同的胸腺细胞群。然而，值得注意的是，在这种中等水平的锌缺乏下，cDNA阵列分析发现了四个潜在的锌调控mrna，它们的调节被独立地证实了两次，使用半定量和实时定量逆转录-聚合酶链反应。其中一个基因（髓细胞白血病序列-1）的表达被抑制，而其他基因（DNA损伤修复和重组蛋白23B、小鼠层粘连蛋白受体和淋巴细胞特异性蛋白酪氨酸激酶（LCK））的表达在缺锌小鼠中升高。进一步的Western分析表明，锌结合蛋白LCK在这些缺锌小鼠中升高。结果表明，在FACS分析检测到胸腺细胞发育发生改变之前，3周的膳食锌不足可以改变胸腺特异性mRNA和蛋白质丰度。
The detrimental sequelae of severe zinc deficiency on the thymus and T-lymphocyte compartment of the mammalian immune system have been established, but underlying mechanisms remain unknown. Hypothesizing that the alterations in T-lymphocyte number and function observed during zinc deficiency may result from changes in gene expression, we sought to compare thymic mRNA expression profiles of zinc-deficient and zinc-normal mice utilizing cDNA arrays. For our murine model described herein, 3 wk of dietary zinc deficiency did not perturb food intake or growth rate in young adult, outbred mice, but significantly depressed multiple parameters of zinc status. Furthermore, fluorescence-activated cell sorting (FACS) analysis demonstrated no changes in thymocyte populations expressing the cell surface markers CD3, CD4 or CD8, establishing that observed changes in mRNA abundances were not attributable to different thymocyte populations. Yet notably, at this moderate level of zinc deficiency, cDNA array analysis identified four potentially zinc-regulated mRNAs whose modulation was confirmed independently, twice, using both semiquantitative and real-time quantitative reverse transcription-polymerase chain reaction. Expression of one of these genes (myeloid cell leukemia sequence-1) was depressed, whereas the others [DNA damage repair and recombination protein 23B, the mouse laminin receptor and the lymphocyte-specific protein tyrosine kinase (LCK)] were elevated in the zinc-deficient mice. Further Western analysis demonstrated that the zinc binding protein LCK was elevated in these zinc-deficient mice. Results demonstrate that 3 wk of dietary zinc insufficiency can alter specific thymic mRNA and protein abundances before alterations occur in thymocyte development as detectable by FACS analysis.