著者

Kohta Nakatani Yoshihiro Izumi Kosuke Hata Takeshi Bamba

出版者

The Mass Spectrometry Society of Japan

雑誌

Mass Spectrometry (ISSN:2187137X)

巻号頁・発行日

vol.9, no.1, pp.A0080, 2020-03-17 (Released:2020-03-17)

参考文献数

26

被引用文献数

25

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The rapid development of next-generation sequencing techniques has enabled single-cell genomic and transcriptomic analyses, which have revealed the importance of heterogeneity in biological systems. However, analytical methods to accurately identify and quantify comprehensive metabolites from single mammalian cells with a typical diameter of 10–20 μm are still in the process of development. The aim of this study was to develop a single-cell metabolomic analytical system based on highly sensitive nano-liquid chromatography tandem mass spectrometry (nano-LC-MS/MS) with multiple reaction monitoring. A packed nano-LC column (3-μm particle-size pentafluorophenylpropyl Discovery HSF5 of dimensions 100 μm i.d.×180 mm) was prepared using a slurry technique. The optimized nano-LC-MS/MS method showed 3–132-fold (average value, 26-fold) greater sensitivity than semimicro-LC-MS/MS, and the detection limits for several hydrophilic metabolites, including amino acids and nucleic acid related metabolites were in the sub-fmol range. By combining live single-cell sampling and nano-LC-MS/MS, we successfully detected 18 relatively abundant hydrophilic metabolites (16 amino acids and 2 nucleic acid related metabolites) from single HeLa cells (n=22). Based on single-cell metabolic profiles, the 22 HeLa cells were classified into three distinct subclasses, suggesting differences in metabolic function in cultured HeLa cell populations. Our single-cell metabolomic analytical system represents a potentially useful tool for in-depth studies focused on cell metabolism and heterogeneity.

著者

Toshinobu Hondo Chihiro Ota Kohta Nakatani Yumi Miyake Hiroshi Furutani Takeshi Bamba Michisato Toyoda

出版者

The Mass Spectrometry Society of Japan

雑誌

Mass Spectrometry (ISSN:2187137X)

巻号頁・発行日

vol.11, no.1, pp.A0112, 2022-12-29 (Released:2022-12-29)

参考文献数

24

被引用文献数

1

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Proton-transfer-reaction (PTR) mass spectrometry (MS), a widely used method for detecting trace-levels of volatile organic compounds in gaseous samples, can also be used for the analysis of small non-volatile molecules by using supercritical fluid as a transporter for the molecules. Supercritical fluid extraction (SFE) is a method that permits lipophilic compounds to be rapidly and selectively extracted from complex matrices. The combination of the high sensitivity of PTR MS with the SFE is a potentially novel method for analyzing small molecules in a single cell, particularly for the analysis of lipophilic compounds. We preliminarily evaluated this method for analyzing the components of a single HeLa cell that is fixed on a stainless steel frit and is then directly introduces the SFE extracts into the PTR MS. A total of 200/91 ions were observed in positive/negative ion mode time-of-flight mass spectra, and the masses of 11/10 ions could be matched to chemical formulae obtained from the LipidMaps lipids structure database. Using various authentic lipophilic samples, the method could be used to detect free fatty acids in the sub-femtomole to femtomole order in the negative ion mode, the femtomole to sub-picomole order for fat-soluble vitamins, and the picomole order for poly aromatic hydrocarbons in both the positive and negative ion mode.

著者

Kazuo Omori Naoto Katakami Shoya Arakawa Yuichi Yamamoto Hiroyo Ninomiya Mitsuyoshi Takahara Taka-aki Matsuoka Hiroshi Tsugawa Masahiro Furuno Takeshi Bamba Eiichiro Fukusaki Iichiro Shimomura

出版者

Japan Atherosclerosis Society

雑誌

Journal of Atherosclerosis and Thrombosis (ISSN:13403478)

巻号頁・発行日

pp.52506, (Released:2020-01-25)

参考文献数

32

被引用文献数

15

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Aim: An identification of the high-risk group of atherosclerotic cardiovascular disease (CVD) is important in the management of patients with diabetes. Metabolomics is a potential tool for the discovery of new biomarkers. With this background, we aimed to identify metabolites associated with atherosclerosis in patients with type 2 diabetes mellitus (T2DM). Methods: A total of 176 patients with T2DM who have never had a CVD event and 40 who were survivors of coronary artery disease (CAD) events were enrolled. Non-targeted metabolome analysis of fasting plasma samples was performed using gas chromatography coupled with mass spectrometry (GC/MS) highly optimized for multiple measurement of blood samples. First, metabolites were screened by analyzing the association with the established markers of subclinical atherosclerosis (i.e., carotid maximal intima-media thickness (max-IMT) and flow-mediated vasodilation (FMD)) in the non-CVD subjects. Then, the associations between the metabolites detected and the history of CAD were investigated. Result: A total of 65 annotated metabolites were detected. Non-parametric univariate analysis identified inositol and indoxyl sulfate as significantly (p<0.05) associated with both max-IMT and FMD. These metabolites were also significantly associated with CAD. Moreover, inositol remained to be associated with CAD even after adjustments for traditional coronary risk factors. Conclusions: We identified novel biomarker candidates for atherosclerosis in Japanese patients with T2DM using GC/MS-based non-targeted metabolomics.