Zaitsu Kei, Hayashi Yumi, Murata Tasuku, Ohara Tomomi, Nakagiri Kenta, Kusano Maiko, Nakajima Hiroki, Nakajima Tamie, Ishikawa Tetsuya, Tsuchihashi Hitoshi, Ishii Akira
In Vivo Real-Time Omics Laboratory, Institute for Advanced Research, Nagoya University , Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan.
Department of Legal Medicine & Bioethics, Nagoya University Graduate School of Medicine , 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
Anal Chem. 2016 Apr 5;88(7):3556-61. doi: 10.1021/acs.analchem.5b04046. Epub 2016 Mar 9.
Probe electrospray ionization (PESI) is a recently developed ionization technique that enables the direct detection of endogenous compounds like metabolites without sample preparation. In this study, we have demonstrated the first combination use of PESI with triple quadrupole tandem mass spectrometry (MS/MS), which was then applied to intact endogenous metabolite analysis of mice liver, achieving detection of 26 metabolites including amino acids, organic acids, and sugars. To investigate its practicality, metabolic profiles of control and CCl4-induced acute hepatic injury mouse model were measured by the developed method. Results showed clear separation of the two groups in score plots of principal component analysis and identified taurine as the primary contributor to group separation. The results were further validated by the established gas chromatography/MS/MS method, demonstrating the present method's usefulness. In addition, we preliminarily applied the method to real-time analysis of an intact liver of a living mouse. We successfully achieved monitoring of the real-time changes of two tricarboxylic acid cycle intermediates, α-ketoglutaric acid and fumaric acid, in the liver immediately after pyruvic acid injection via a cannulated tube to the portal vein. The present method achieved an intact analysis of metabolites in liver without sample preparation, and it also demonstrates future possibility to establish in vivo real-time metabolome analysis of living animals by PESI/MS/MS.
探针电喷雾电离（PESI）是一种最近开发的电离技术，它能够在无需样品制备的情况下直接检测内源性化合物，如代谢物。在本研究中，我们首次展示了PESI与三重四极杆串联质谱（MS/MS）的联合使用，随后将其应用于小鼠肝脏内源性代谢物的完整分析，成功检测到26种代谢物，包括氨基酸、有机酸和糖类。为了研究其实用性，我们使用所开发的方法测量了对照小鼠和四氯化碳诱导的急性肝损伤小鼠模型的代谢谱。结果表明，在主成分分析的得分图中，两组有明显分离，并确定牛磺酸是导致组间分离的主要因素。通过已建立的气相色谱/MS/MS方法进一步验证了结果，证明了本方法的实用性。此外，我们初步将该方法应用于活体小鼠肝脏的实时分析。通过经插管至门静脉向肝脏注射丙酮酸后，我们成功实现了对肝脏中两种三羧酸循环中间体α-酮戊二酸和富马酸实时变化的监测。本方法无需样品制备即可对肝脏中的代谢物进行完整分析，同时也展示了未来通过PESI/MS/MS建立活体动物体内实时代谢组分析的可能性。
