-Original-

Pattern Recognition Analysis of Proton Nuclear Magnetic Resonance Spectra of Extracts of Intestinal Epithelial Cells under Oxidative Stress

Keiji Nakata¹, Norio Sato², Keiko Hirakawa³, Takayuki Asakura¹, Takao Suzuki², Ran Zhu⁴, Takeshi Asano⁵, Kaoru Koike², Youkichi Ohno³ and Hiroyuki Yokota¹

¹Department of Emergency and Critical Care Medicine, Nippon Medical School
²Department of Primary Care and Emergency Medicine, Kyoto University
³Department of Legal Medicine and NMR Laboratory, Nippon Medical School
⁴Department of Critical Care Medicine, 1st Affiliated Hospital of China Medical University, China
⁵Department of Pediatrics, Nippon Medical School

Background: Mesenteric ischemia-reperfusion induces gut mucosal damage. Intestinal mucosal wounds are repaired by epithelial restitution. Although many different molecular mechanisms have been shown to affect cell metabolism under oxidative conditions, these molecular mechanisms and metabolic phenotypes are not well understood. Nuclear magnetic resonance (NMR) spectroscopic data can be used to study metabolic phenotypes in biological systems. Pattern recognition with multivariate analysis is one chemometric technique. The purpose of this study was to visualize, using a chemometric technique to interpret NMR data, different degrees of oxidant injury in rat small intestine (IEC-6) cells exposed to H₂O₂.
Methods: Oxidant stress was induced by H₂O₂ in IEC-6 cells. Cell restitution and viability were assessed at different H₂O₂ concentrations and time points. Cells were harvested for pattern recognition analysis of ¹H-NMR data.
Results: Cell viability and restitution were significantly suppressed by H₂O₂ in a dose-dependent manner compared with control. Each class was clearly separated into clusters by partial least squares discriminant analysis, and class variance was greater than 90% from 2 factors.
Conclusion: Pattern recognition of NMR spectral data using a chemometric technique clearly visualized the differences of oxidant injury in IEC-6 cells under oxidant stress.

J Nippon Med Sch 2014; 81: 236-247

Keywords
pattern recognition, partial least squares discriminant analysis, nuclear magnetic resonance, oxidant stress

Correspondence to
Norio Sato, Department of Primary Care and Emergency Medicine, Kyoto University, 54 Kawaramachi, Shogoin, Sakyoku, Kyoto, 606-8507, Japan
drnori@kuhp.kyoto-u.ac.jp

Received, April 30, 2013
Accepted, January 6, 2014