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Forensic application of microRNA-706 as a biomarker for drowning pattern identification
SeonYoung Yu1, Joo-Young Na2, Young-Jik Lee3
1Department of Forensic Medicine, Chonnam National University Medical School, Gwangju, Republic of Korea; Research Institute of Forensic Science, Chonnam National University Medical School, Gwangju, Republic of Korea.
Abstract:
Forensic research using microRNA has been used so far only for the identification of body fluids, but its use in understanding biological processes in post-mortem pathology has not been studied before. Therefore, we performed experiments in mice to compare between freshwater and saltwater drowning models, and miRNA expression was analyzed in the brain through a forward bioinformatics screening approach. In this study, we identified eight specific microRNAs whose expression increased in freshwater and decreased in saltwater. Among them, miR-706 - targeting HCN1 - was identified as a potent biomarker for the drowning pattern identification. A higher expression of miR-706 was detected in the freshwater drowning compared to the control and saltwater drowning group (p<0.05, and p<0.01, respectively). HCN1 mRNA expression, a suggested candidate target for miR-706, was lower in the freshwater (p<0.01) than in the saltwater drowning group, and showed statistical difference between freshwater and saltwater drowning (p<0.01). miR-706 was specifically expressed in the hippocampal neurons as detected by in situ hybridization. Our data suggest that a specific microRNA may provide clues to understanding some crime scene investigations and pathobiological processes in the dead body.
Insights
Forensic microRNA analysis can now distinguish drowning types. Specific microRNAs, like miR-706, show altered brain expression after freshwater versus saltwater drowning, aiding post-mortem investigations.
Area of Science:
- Forensic Science
- Molecular Biology
- Pathology
Background:
- MicroRNA (miRNA) research in forensics has been limited to body fluid identification.
- The role of miRNA in post-mortem pathological processes, specifically drowning, remains unexplored.
Purpose of the Study:
- To investigate differential miRNA expression in the brain following freshwater versus saltwater drowning in a mouse model.
- To identify potential miRNA biomarkers for distinguishing drowning patterns in forensic pathology.
Main Methods:
- Comparative analysis of miRNA expression in mouse brains using a bioinformatics screening approach.
- Differential expression analysis of specific miRNAs and their target genes (HCN1 mRNA).
- In situ hybridization to determine the cellular localization of key miRNAs.
Main Results:
- Eight specific miRNAs showed altered expression patterns between freshwater and saltwater drowning models.
- miR-706 expression was significantly higher in freshwater drowning compared to controls and saltwater drowning.
- HCN1 mRNA expression was significantly lower in freshwater drowning compared to saltwater drowning, suggesting miR-706 regulation.
- miR-706 was localized to hippocampal neurons.
Conclusions:
- Specific microRNAs, notably miR-706, can serve as biomarkers for differentiating between freshwater and saltwater drowning.
- These findings offer novel insights into the pathobiological processes of drowning and potential applications in forensic investigations.
