Early postmortem interval estimation based on Cdc25b mRNA in rat cardiac tissue

• Published in: Legal medicine (Tokyo, Japan) Vol. 35; pp. 18 - 24
• Main Authors: Tao, Li, Ma, Jianlong, Han, Liujun, Xu, Hongmei, Zeng, Yan, Yehui, Lyu, Li, Wencan, Ma, Kaijun, Xiao, Bi, Chen, Long
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 01.11.2018
• Subjects: Animals; Biomarkers - metabolism; cdc25 Phosphatases - genetics; cdc25 Phosphatases - metabolism; Early postmortem interval; Forensic medicine; Forensic Medicine - methods; Male; Microarray Analysis; Microarray expression profile; Models, Theoretical; mRNA; Myocardium - metabolism; Pilot Projects; Polymerase Chain Reaction - methods; Postmortem Changes; qPCR; R software; Rats, Sprague-Dawley; RNA, Messenger - metabolism; Temperature; Time Factors; R software; mRNA; qPCR; Microarray expression profile; Forensic medicine; Early postmortem interval
• ISSN: 1344-6223; 1873-4162
• DOI: 10.1016/j.legalmed.2018.09.004

•Overall, 217 time-dependent mRNAs of 31,099 were systematically detected by microarray profiles.•The expression level of Cdc25b had the strongest correlation within the first 24 h postmortem.•Cdc25b was the optimal biomarker for the early postmortem interval (up to 24 h).•We built a new model that applied to the case from 25 to 35 °C using the R software. 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.