Evaluation of biomolecular distributions in rat brain tissues by means of ToF-SIMS using a continuous beam of Ar clusters.
Evaluation of biomolecular distributions in rat brain tissues by means of ToF-SIMS using a continuous beam of Ar clusters.
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DOI：
10.1116/1.4939251
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发表时间：
2016-01
期刊：
影响因子：
2.1
通讯作者：
S. Nakano;Yuta Yokoyama;S. Aoyagi;Naoyuki Himi;J. Fletcher;N. Lockyer;Alex Henderson;J. Vickerman
中科院分区：
文献类型：
--
作者：
S. Nakano;Yuta Yokoyama;S. Aoyagi;Naoyuki Himi;J. Fletcher;N. Lockyer;Alex Henderson;J. Vickerman
飞行时间二次离子质谱（ToF-SIMS）提供详细的化学结构信息和高空间分辨率图像。因此，ToF-SIMS可用于研究缺血等生物现象。本研究采用ToF-SIMS测定脑缺血后生物分子的分布，以评价脑微梗死。ToF-SIMS数据集通过多变量分析来解释含有未知信息的复杂样品，并获得来自目标生物分子的片段离子指示的生物分子定位。使用传统的ToF-SIMS（一次离子源：Bi簇离子），很难检测到超过约1000 u的二次离子。此外，即使质量低于1000 u，与生物分子相关的二次离子强度也不总是高到足以成像，因为浓度很低。然而，对于观察组织中的生物分子分布，检测来自组织特定区域的低量生物分子是很重要的。用ToF-SIMS （J105, Ionoptika, Ltd, Chandlers Ford， UK）测量大鼠脑组织样品，使用连续的Ar簇束作为主要离子源。具有Ar簇的ToF-SIMS可以有效地检测与生物分子和大分子相关的二次离子。ToF-SIMS检测到的分子采用多变量分析对ToF-SIMS数据进行分析。将直径45 μm的微球注入大鼠单侧颈内动脉（MS大鼠）致脑微梗死。将大鼠脑切片，用ToF-SIMS进行测量。对正常大鼠和多发性硬化症大鼠的脑样本进行检测，寻找与重要生物分子相关的特异性二次离子，并分析两者之间的差异。最后，在MS大鼠血管周围发现了特定的二次离子。结果表明，ToF-SIMS可以检测到与脑微梗死相关的重要生物分子。
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides detailed chemical structure information and high spatial resolution images. Therefore, ToF-SIMS is useful for studying biological phenomena such as ischemia. In this study, in order to evaluate cerebral microinfarction, the distribution of biomolecules generated by ischemia was measured with ToF-SIMS. ToF-SIMS data sets were analyzed by means of multivariate analysis for interpreting complex samples containing unknown information and to obtain biomolecular mapping indicated by fragment ions from the target biomolecules. Using conventional ToF-SIMS (primary ion source: Bi cluster ion), it is difficult to detect secondary ions beyond approximately 1000 u. Moreover, the intensity of secondary ions related to biomolecules is not always high enough for imaging because of low concentration even if the masses are lower than 1000 u. However, for the observation of biomolecular distributions in tissues, it is important to detect low amounts of biological molecules from a particular area of tissue. Rat brain tissue samples were measured with ToF-SIMS (J105, Ionoptika, Ltd., Chandlers Ford, UK), using a continuous beam of Ar clusters as a primary ion source. ToF-SIMS with Ar clusters efficiently detects secondary ions related to biomolecules and larger molecules. Molecules detected by ToF-SIMS were examined by analyzing ToF-SIMS data using multivariate analysis. Microspheres (45 μm diameter) were injected into the rat unilateral internal carotid artery (MS rat) to cause cerebral microinfarction. The rat brain was sliced and then measured with ToF-SIMS. The brain samples of a normal rat and the MS rat were examined to find specific secondary ions related to important biomolecules, and then the difference between them was investigated. Finally, specific secondary ions were found around vessels incorporating microspheres in the MS rat. The results suggest that important biomolecules related to cerebral microinfarction can be detected by ToF-SIMS.