Postmortem quantitative mRNA analyses of death investigation in forensic pathology: an overview and prospects

To analyze pathophysiological dynamics of the death process using mRNA quantification, previous studies investigated pulmonary surfactant-associated protein (SP-A), as well as hypoxia-inducible factor 1 (HIF-1) and its downstream factors. Quantitative assays of these mRNA transcripts were established using TaqMan real-time RT-PCR. Experimental studies showed that most of these factors in forensic autopsy materials gradually degraded in patterns similar to those of endogenous references during the early postmortem period within 48h; postmortem interference might not usually be significant in relative mRNA quantification. Subsequent mRNA analyses of these factors in serial autopsy cases suggested their potential usefulness to investigate the pathophysiology of the death process. Further analyses of VEGF and GLUT1 mRNA in the lung and skeletal muscle shed light on tissue ischemia/hypoxia and subsequent tissue-dependent pathological changes leading to death after injury. Animal experiments partly supported the above-mentioned findings and also suggested further potential mRNA targets for practical use. These studies on postmortem quantitative mRNA analyses might offer insight into pathophysiological mechanisms in the death process, suggesting that systemic postmortem quantitative mRNA analyses from multi-faceted aspects of molecular biology can be developed and incorporated into death investigations in forensic pathology, to support and reinforce morphological evidence.