RNA degradation as described by a mathematical model for postmortem interval determination.
Precisely determining the postmortem interval (PMI) is crucial to civil, criminal and forensic cases. A technique to exploit the postmortem RNA transcript level was developed to increase the accuracy and practicality of PMI estimation. For this purpose, lung tissues and muscle tissues were removed at twelve time points (0-144 h) from rat corpses that had been stored at three different temperatures (10, 20 and 30 °C). Human tissues were collected at autopsy from twelve real cases with known PMI values and other parameters. After the RNA was extracted from all these samples, the transcript levels of nine biomarkers were analyzed by real-time quantitative PCR (RT-qPCR). With the assistance of geNorm, miR-195, miR-200c, 5S, U6 and RPS29 were selected as reference biomarkers for lung specimens; miR-1, miR-206, 5S and RPS29 were chosen as control markers for muscle tissues. On the contrary, ACTB and GAPDH were significantly correlated with the PMI. The mathematical models using these target biomarkers were constructed to describe the characteristic relationship between △Ct values (normalized to reference biomarkers) and the observed PMI for each temperature group. Following validation, the relatively low error rates (7.4% and 12.5% for rat and human samples, respectively) demonstrated the accuracy and reliability of the mathematical model. We believe these results indicate that the multi-parametric mathematical model can become a practical tool for PMI estimation.
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Shanghai, 200032, People's Republic of China; Department of Physiology & Pathophysiology, School of Basic Medical Sciences, Fudan University, 130 Dongan Road, Shanghai, 200032, People's Republic of China; Shanghai University of Medicine & Health Sciences, 21 Meilong Road, Shanghai, 200030, People's Republic of China.
Ye-Hui
YH
Lv
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Shanghai, 200032, People's Republic of China.
Jian-Long
JL
Ma
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Shanghai, 200032, People's Republic of China.
Hui
H
Pan
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Shanghai, 200032, People's Republic of China; Department of Physiology & Pathophysiology, School of Basic Medical Sciences, Fudan University, 130 Dongan Road, Shanghai, 200032, People's Republic of China.
Heng
H
Zhang
Shanghai Public Security Bureau, Pudong Branch, 655 Dingxiang Road, Shanghai, 200032, People's Republic of China.
Wen-Can
WC
Li
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Shanghai, 200032, People's Republic of China.
Ai-Min
AM
Xue
Children's Hospital of Fudan University, 399 Wanyuan Road, Shanghai, 201102, People's Republic of China.
Hui-Jun
HJ
Wang
Forensic Lab, Criminal Science and Technology Institute, Shanghai Public Security Bureau, 803 North Zhongshan Road, Shanghai, 200082, People's Republic of China.
Kai-Jun
KJ
Ma
Department of Forensic Medicine, School of Basic Medical Sciences, Fudan University, 131 Dongan Road, Shanghai, 200032, People's Republic of China. Electronic address: chenlong@shmu.edu.cn.
Long
L
Chen
D000199:Actins / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000818:Animals; D002675:Child, Preschool; D005260:Female; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008297:Male; D035683:MicroRNAs / Q000378:metabolism; D008875:Middle Aged; D015233:Models, Statistical; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D011180:Postmortem Changes; D020871:RNA Stability; D012335:RNA, Ribosomal / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D060888:Real-Time Polymerase Chain Reaction; D012269:Ribosomal Proteins / Q000378:metabolism
D000199:Actins; D035683:MicroRNAs; D012335:RNA, Ribosomal; D012269:Ribosomal Proteins; D024581:Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)
Forensic science; Mathematical model; Postmortem interval (PMI); RNA degradation; Real-time quantitative polymerase chain reaction (RT-qPCR); Reference biomarker