MicroRNA transcriptome analysis for post-mortem interval estimation

Estimating the post-mortem interval (PMI) is a critical aspect of forensic science; however, current methods often lack precision because of the variability in external and internal factors. This study investigated the potential use of microRNAs (miRNAs) as stable molecular biomarkers for PMI estimation. We analysed the miRNA expression profiles in myocardial tissue from 18 BALB/c mice sampled at six PMIs (0, 12, 24, 36, 48 h, and 6 d) using high-throughput sequencing and qRT-PCR. In total, 154 differentially expressed (DE) miRNAs were identified, of which 55 were upregulated and 99 were downregulated. Five upregulated (miR-206-3p, miR-200a-3p, miR-205-5p, miR-200b-3p, miR-429-3p) and four downregulated (miR-541-5p, miR-455-3p, miR-30c-5p, and miR-149-5p) apoptosis-related miRNAs were validated through qRT-PCR analysis, indicating their potential as supportive biomarkers in PMI estimation. Gene ontology analysis revealed their involvement in processes such as cardiac muscle cell proliferation, nuclear migration, and miRNA metabolic regulation. Linear regression models demonstrated significant correlations between specific miRNA expression levels and the PMI. These findings provide a molecular basis that may contribute to improving PMI estimation accuracy and supporting forensic methodologies.