Cell survival and DNA damage repair are promoted in the human blood thanatotranscriptome shortly after death

Abstract

RNA analysis of post-mortem tissues, or thanatotranscriptomics, has become a topic of interest in forensic science due to the essential information it can provide in forensic investigations. Several studies have previously investigated the effect of death on gene transcription, but it has never been conducted with samples of the same individual. For the first time, a longitudinal mRNA expression analysis study was performed with post-mortem human blood samples from individuals with a known time of death. The results reveal that, after death, two clearly differentiated groups of up- and down-regulated genes can be detected. Pathway analysis suggests active processes that promote cell survival and DNA damage repair, rather than passive degradation, are the source of early post-mortem changes of gene expression in blood. In addition, a generalized linear model with an elastic net restriction predicted post-mortem interval with a root mean square error of 4.75 h. In conclusion, we demonstrate that post-mortem gene expression data can be used as biomarkers to estimate the post-mortem interval though further validation using independent sample sets is required before use in forensic casework.

From flesh to bones: Multi‐omics approaches in forensic science

“…Additionally, these results suggest that the postmortem response is organ-and species-dependent, so specific studies should be conducted to identify suitable mRNA markers, human-and organ-specific. More recently, a work conducted longitudinally on human blood from seven individuals at known PMIs (up to 38 hours) identified two groups of up-and down-regulated genes associated with increasing time elapsed since death [210]. In general, they observed the activation of DNA damage repair genes and the suppression of finally with blood coagulation and response to stress, particularly between 7 and 14 hours post-mortem [201].…”