Quantitative imaging of deuterated metabolic tracers in biological tissues with nanoscale secondary ion mass spectrometry
Quantitative imaging of deuterated metabolic tracers in biological tissues with nanoscale secondary ion mass spectrometry
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DOI：
10.1016/j.ijms.2017.08.004
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发表时间：
2017-11-01
影响因子：
1.8
通讯作者：
Steinhauser, Matthew L.
中科院分区：
文献类型：
--
作者：
Guillermier, Christelle;Poczatek, J. Collin;Steinhauser, Matthew L.
在纳米尺度的二次离子质谱（NanoSIMS）领域中，用于常规测量亚100 nm域中的同位素比率的并行检测器的配置将经典的稳定同位素示踪剂研究从整个组织水平下至亚细胞器水平。在过去的十年中，稳定同位素示踪剂与NanoSIMS的结合已经应用于一系列基本的生物学问题，这些问题在很大程度上是通过其他手段无法解决的。虽然多重测量不同的稳定同位素示踪剂是可行的，但在实践中，目前的分析能力仍然存在差距，无法有效地测量示踪剂研究中常用的稳定同位素。一个这样的例子是氘示踪剂的测量。测量氘/氢同位素比最明显的方法是在质量2/1。然而，磁扇区的半径限制了对生物样品的多路探测至关重要的其他质量的伴随测量。在这里，我们确定的实验参数，以测量氘示踪剂在生物样品中使用的C2 H-多原子离子物种（C2 D-/C2 H-），同时操作的NanoSIMS在降低质量分辨率为14000。通过溅射参数的控制，我们证明，有一个分析窗口，在此期间的C2 D-/C2 H-同位素比可以测量足够的精度为生物学研究的D-标记的程度通常远高于自然丰度。我们通过比较小鼠小肠中D-水标记的C2 D测量与在相同分析领域中进行的天然D/H测量来验证该方法。其他概念验证演示包括测量生物样本中的D-水、D-葡萄糖和D-胸苷。因此，本研究提供了一个实用的模板氘基示踪剂在生物系统中的研究。(C)2017爱思唯尔B. V.保留所有权利。
In the field of secondary ion mass spectrometry at nanometer scale (NanoSIMS), configuration of parallel detectors to routinely measure isotope ratios in sub-100 nm domains brings classical stable isotope tracer studies from the whole tissue level down to the suborganelle level. Over the past decade, the marriage of stable isotope tracers with NanoSIMS has been applied to a range of fundamental biological questions that were largely inaccessible by other means. Although multiplexed measurement of different stable isotope tracers is feasible, in practice there remains a gap in the current analytical capacity to efficiently measure stable isotopes commonly utilized in tracer studies. One such example is the measurement of deuterated tracers. The most obvious approach to measuring deuterium/hydrogen isotope ratios is at mass 2/1. However, the radius of the magnetic sector limits concomitant measurement of other masses critical to multiplexed exploration of biological samples. Here we determine the experimental parameters to measure deuterated tracers in biological samples using the C2H- polyatomic ion species (C2D-/C2H-) while operating the NanoSIMS at a reduced Mass Resolving Power of 14,000. Through control of the sputtering parameters, we demonstrate that there is an analytical window during which the C2D-/C2H- isotope ratio can be measured with sufficient precision for biological studies where the degree of D-labeling is typically well above natural abundance. We provide validation of this method by comparing the C2D measurement of D-water labeling in the murine small intestine relative to measurements of native D/H conducted in the same analytical fields. Additional proof-of-concept demonstrations include measurement of D-water, D-glucose, and D-thymidine in biological specimens. Therefore, this study provides a practical template for deuterium-based tracer studies in biological systems. (C) 2017 Elsevier B.V. All rights reserved.