Introduction

Application of metabolomic methods to forensic studies may expand the limits of the post-mortem interval (PMI) estimation, and improve the accuracy of the estimation. To this end, it is important to determine which tissue is the most suitable for analysis, and which compounds are the most promising candidates for PMI estimation.

Objectives

This work is aimed at the comparison of human serum, aqueous humor (AH), and vitreous humor (VH) as perspective tissues for metabolomic-based PMI estimation, at the determination of most promising PMI biomarkers, and at the development of method of PMI estimation based on the measurement of concentrations of PMI biomarkers.

Methods

Quantitative metabolomic profiling of samples of the human serum, AH, and VH taken at different PMIs has been performed with the use of NMR spectroscopy.

Results

It is found that the metabolomic changes in anatomically isolated ocular fluids are slower and smoother than that in blood. A good positive time correlation (Pearson coefficient r > 0.5) was observed for several metabolites, including hypoxanthine, choline, creatine, betaine, glutamate, and glycine. A model for PMI estimation based on concentrations of several metabolites in AH and VH is proposed.

Conclusions

The obtained results demonstrate that the metabolomic analysis of AH and VH is more suitable for the PMI estimation than that of serum. The compounds with good positive time correlation can be considered as potential PMI biomarkers.

中文翻译：

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人体血清，房水和玻璃体液的代谢组学分布的验尸变化。

介绍

代谢组学方法在法医研究中的应用可能会扩大验尸间隔（PMI）估计的范围，并提高估计的准确性。为此，重要的是确定哪个组织最适合分析，哪些化合物最适合用于PMI估计。

目标

这项工作旨在比较人体血清，房水（AH）和玻璃体液（VH），作为基于代谢组学的PMI估计的透视组织，确定最有前途的PMI生物标志物，以及开发PMI方法基于PMI生物标志物浓度的测量结果进行估算。

方法

已经使用NMR光谱法对在不同PMI处采集的人血清，AH和VH样品进行了代谢组学定量分析。

结果

发现在解剖上分离的眼液中的代谢组学变化比血液中的代谢组学变化更慢和更平滑。 观察到几种代谢物包括次黄嘌呤，胆碱，肌酸，甜菜碱，谷氨酸和甘氨酸具有良好的正时间相关性（皮尔森系数r > 0.5）。提出了基于AH和VH中几种代谢物浓度的PMI估计模型。

结论

所得结果表明，与血清相比，AH和VH的代谢组学分析更适合于PMI估计。具有良好正时间相关性的化合物可以被认为是潜在的PMI生物标志物。