Tao Li, Ma Jianlong, Han Liujun, Xu Hongmei, Zeng Yan, Yehui Lyu, Li Wencan, Ma Kaijun, Xiao Bi, Chen Long
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131Dongan Road, Shanghai 200032, China.
Shenzhen Institute of Criminal Science and Technology, Investigation Department of Shenzhen Public Security Bureau, Key Laboratory of Forensic Pathology, Ministry of Public Security, Shenzhen, 518000,China.
Leg Med (Tokyo). 2018 Nov;35:18-24. doi: 10.1016/j.legalmed.2018.09.004. Epub 2018 Sep 10.
The postmortem interval (PMI) is the amount of time that has elapsed since the time of death. Over the years, many approaches have been developed to assess PMI, but their time frame of applicability has been only days to weeks. Our present pilot study aimed to find the sensitive mRNA marker if the degradation of mRNA could be used to estimate the early postmortem interval (up to 24 h).
In our study, we use the microarray to screen 217 mRNAs markers of rat cardiac tissue. Then, real-time fluorescent quantitative PCR (qPCR) was used to validate of the candidate markers at 7 time points within 24 h and at temperatures of 25 °C and 35 °C. Another 27 rats were then used to verify the model.
Among all of the candidate markers, △Cq (cell division cycle 25 homolog B(Cdc25b)) had the best correlation coefficient with early postmortem interval and was used to build a new model using the R software. The results of verification testing demonstrated that the error rate was less than 15%, demonstrating the high predictive power of our mathematical model.
In this study, Cdc25b was found to be the sensitive marker to estimate early postmortem interval, and Rpl27 was found to be suitable for use as the endogenous control. Our work provided new leads for molecular approaches to early postmortem interval estimation using the significant mRNA markers established here.
死后间隔时间（PMI）是指自死亡时刻起所经过的时间量。多年来，已开发出许多方法来评估PMI，但其适用的时间范围仅为几天至几周。我们目前的初步研究旨在寻找敏感的mRNA标记物，以确定mRNA的降解是否可用于估计早期死后间隔时间（长达24小时）。
在我们的研究中，我们使用微阵列筛选大鼠心脏组织的217个mRNA标记物。然后，使用实时荧光定量PCR（qPCR）在24小时内的7个时间点以及25°C和35°C的温度下对候选标记物进行验证。随后使用另外27只大鼠来验证该模型。
在所有候选标记物中，△Cq（细胞分裂周期25同源物B（Cdc25b））与早期死后间隔时间的相关系数最佳，并使用R软件建立了一个新模型。验证测试结果表明，错误率小于15%，证明了我们数学模型的高预测能力。
在本研究中，发现Cdc25b是估计早期死后间隔时间的敏感标记物，发现Rpl27适合用作内参。我们的工作为使用此处建立的重要mRNA标记物进行早期死后间隔时间估计的分子方法提供了新的线索。
