Application of 1H-NMR-based pattern recognition in plasma metabolomics of rats with diffuse axonal injury

Abstract:

Objective：To investigate the feasibility of applying 1H-NMR-based pattern recognition in the studies of plasma metabo－nomics of Sprague-Dawley（SD） rats with diffuse axonal injury（DAI） and identify potential metabolic markers of DAI at early stage. Methods：Modified Marmarou A method was used to establish the model of DAI in SD rats. All animals were sacrificed at 1 d post in－sult. Plasma was prepared with heart blood. 1H-NMR technique was applied for detection of plasma samples from sham-injured group（n=6） and injured group（n=6）. Pattern recognition of partial least squares discriminant analysis（PLS-DA） and orthogonal signal correction-partial least squares discriminant analysis（OPLS-DA） were used to analyze and determine the differences of plasma metabolites between the two groups. Results：Different metabolites between sham-injured group and injured group were found by cor－relation analysis and student’s t test，metabolites were selected on condition that correlation coefficient丨r丨＞0.6 and P＜0.05. Finally，Pyruvate（r=-0.831，P=0.019），Lysine（r=-0.773，P=0.030），Glutamate（r=-0.772，P=0.042），Glutamine（r=-0.772，P=0.042），Isobutyrate（r=-0.631，P=0.045） and Glycerol（r=-0.844，P=0.032） significantly increased in injured group compared with those of sham-injured group. Malonate（r=0.699，P=0.038），L2（r=0.786，P=0.047），L3（r=0.666，P=0.031），L4（r=0.715，P=0.022），L10（r=0.663，P=0.025），β-Glucose（r=0.800，P=0.030） and α-Glucose（r=0.808，P=0.015） significantly decreased in in－jured group compared with those of sham-injured group. Conclusion：1H-NMR technique is effective in the study of plasma metabo－nomics of SD rats with DAI. The different metabolites may suggest the possible pathophysiological mechanism of DAI and lay the foundation for the research of early diagnosis，treatment and forensic identification of DAI.