Tsai Fuu-Jen, Chen Shih-Yin, Liu Yu-Ching, Liao Hsin-Yi, Chen Chao-Jung
Graduate Institute of Chinese Medical Science, College of Chinese Medicine, China Medical University, Taichung, Taiwan.
Genetic Center, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.
PLoS One. 2017 Jul 24;12(7):e0181423. doi: 10.1371/journal.pone.0181423. eCollection 2017.
In nanoflow liquid chromatography-matrix-assisted laser desorption/ionization tandem time-of-flight (nanoLC-MALDI-TOF/TOF) approaches, it is critical to directly apply small amounts of the sample elutes on the sample target using a nanoLC system due to its low flow rate of 200 ~ 300 nl/min. It is recommended to apply a sheath liquid containing a matrix with a several μL/min flow rate at the end of the nanoLC column to ensure a larger co-eluted droplet for more reproducible sample spotting and avoid the laborious task of post-manual matrix spotting. In this study, to achieve a better nanoLC-MALDI performance on sample spotting, we first compared α-Cyano-4-hydroxycinnamic acid (CHCA) solvent composition for efficiently concentrating nanoLC elutes on an anchor chip. The solvent composition of isopropanol (IPA): acetonitrile (ACN):acetone:0.1% Trifluoroacetic acid (TFA) (2:7:7:2) provided strong and homogeneous signals with higher peptide ion yields than the other solvent compositions. Then, nanoLC-MALDI-TOF/TOF was applied to study the impact of aflatoxin B1 on the liver proteome from diabetes mellitus type 1 mice. Aflatoxin B1 (AFB1), produced by Aspergillus flavus and Aspergillus parasiticus is a carcinogen and a known causative agent of liver cancer. To evaluate the effects of long-term exposure to AFB1 on type 1 diabetes mellitus (TIDM), the livers of T1DM control mice and mice treated with AFB1 were analyzed using isotope-coded protein labeling (ICPL)-based quantitative proteomics. Our results showed that gluconeogenesis, lipid, and oxidative phosphorylation mechanisms, normally elevated in T1DM, were disordered following AFB1 treatment. In addition, major urinary protein 1 (MUP1), an indicator of increased insulin sensitivity, was significantly decreased in the T1DM/AFB1 group and may have resulted in higher blood glucose levels compared to the T1DM group. These results indicate that T1DM patients should avoid the AFB1 intake, as they could lead to increased blood glucose levels and disorders of energy-producing mechanisms.
在纳流液相色谱-基质辅助激光解吸/电离串联飞行时间质谱（nanoLC-MALDI-TOF/TOF）方法中，由于其200~300 nl/min的低流速，使用纳流液相色谱系统将少量样品洗脱液直接应用于样品靶标至关重要。建议在纳流液相色谱柱末端以几微升/分钟的流速施加含有基质的鞘液，以确保有更大的共洗脱液滴，实现更可重复的样品点样，并避免手动点样基质这一繁琐任务。在本研究中，为了在样品点样方面实现更好的纳流液相色谱-基质辅助激光解吸/电离性能，我们首先比较了α-氰基-4-羟基肉桂酸（CHCA）溶剂组成，以有效地将纳流液相色谱洗脱液浓缩在锚定芯片上。异丙醇（IPA）：乙腈（ACN）：丙酮：0.1%三氟乙酸（TFA）（2:7:7:2）的溶剂组成提供了强而均匀的信号，肽离子产率高于其他溶剂组成。然后，应用纳流液相色谱-基质辅助激光解吸/电离串联飞行时间质谱研究黄曲霉毒素B1对1型糖尿病小鼠肝脏蛋白质组的影响。黄曲霉和寄生曲霉产生的黄曲霉毒素B1（AFB1）是一种致癌物，也是肝癌的已知致病因素。为了评估长期暴露于AFB1对1型糖尿病（TIDM）的影响，使用基于同位素编码蛋白质标记（ICPL）的定量蛋白质组学分析了T1DM对照小鼠和接受AFB1处理的小鼠的肝脏。我们的结果表明，通常在T1DM中升高的糖异生、脂质和氧化磷酸化机制在AFB1处理后紊乱。此外，作为胰岛素敏感性增加指标的主要尿蛋白1（MUP1）在T1DM/AFB1组中显著降低，与T1DM组相比，可能导致血糖水平升高。这些结果表明，T1DM患者应避免摄入AFB1，因为它们可能导致血糖水平升高和能量产生机制紊乱。
