Institute of Forensic Medicine, Catholic University, Largo Francesco Vito 1, 00168 Rome, Italy.
Forensic Sci Int. 2010 Dec 15;203(1-3):99-105. doi: 10.1016/j.forsciint.2010.07.005. Epub 2010 Aug 12.
The usefulness of post-mortem mRNA analysis and its potential applications in forensic casework is currently of interest, especially because of several factors affecting the quality of RNA samples that are not practically predictable. In fact, post-mortem RNA degradation is a complex process that has not been studied systematically. The purpose of this work is to establish whether RNA analysis from post-mortem heart tissue could be used as a forensic tool to investigate the cause of death, with special regard to those cases where a cardiac disease is suspected as the manner of death. We analysed heart tissue from 16 individuals with normal cardiac function, 9 with long post-mortem intervals (L-PMI) and 7 from organ donors with very short PMIs (S-PMIs). Right ventricle tissue was homogenised, and the RNA was isolated and reverse transcribed. The resulting cDNA was used in real-time PCR reactions to quantify the gene expression of beta-glucuronidase (GUSB), Nitric Oxide Synthase 3 (NOS3), Collagen 1 (COL1A1) and Collagen 3 (COL3A1). The percentage of samples with high-quality RNA was higher in samples with S-PMI (7 out of 7) than in samples with L-PMI (4 out of 9, p<0.05). No differences in PMI time or cause of exitus were found between samples with degraded or non-degraded RNA in the L-PMI group. When comparing mRNA levels in samples with non-degraded RNA, we found similar values between the L-PMI and S-PMI groups for GUSB, COL1A1 and COL3A1. The NOS3 gene expression in the L-PMI subgroup was less than half that in the S-PMI. These results suggest that high-quality mRNA can be extracted from post-mortem human hearts only in some cases. Moreover, our data show that mRNA levels are independent from the PMI, even though there are mRNAs in which the expression levels are very susceptible to ischemia times. Clear knowledge about the relationship between mRNA integrity and expression and PMI could allow the use of several mRNAs as forensic tools to contribute to the determination of the cause of death with special regard to cardiovascular diseases.
目前，人们对死后 mRNA 分析的实用性及其在法医学中的潜在应用很感兴趣，特别是因为有几个因素会影响 RNA 样本的质量，而这些因素实际上是无法预测的。事实上，死后 RNA 降解是一个复杂的过程，尚未得到系统研究。本研究旨在确定死后心脏组织的 RNA 分析是否可作为一种法医工具，用于调查死因，特别是那些怀疑心脏疾病为死因的案例。我们分析了 16 例具有正常心脏功能的个体、9 例具有较长死后间隔（L-PMI）的个体和 7 例具有极短 PMI（S-PMI）的器官捐献者的心脏组织。右心室组织匀浆后，提取 RNA 并反转录。所得 cDNA 用于实时 PCR 反应，以定量测定β-葡糖苷酸酶（GUSB）、一氧化氮合酶 3（NOS3）、胶原 1（COL1A1）和胶原 3（COL3A1）的基因表达。S-PMI 组（7 例中有 7 例）的高质量 RNA 样本比例高于 L-PMI 组（9 例中有 4 例，p<0.05）。L-PMI 组中，降解或非降解 RNA 样本的 PMI 时间或死亡原因无差异。在比较非降解 RNA 样本的 mRNA 水平时，我们发现 L-PMI 和 S-PMI 组的 GUSB、COL1A1 和 COL3A1 基因表达相似。L-PMI 亚组的 NOS3 基因表达不到 S-PMI 的一半。这些结果表明，只有在某些情况下才能从死后人心提取高质量的 mRNA。此外，我们的数据表明，mRNA 水平与 PMI 无关，尽管有些 mRNA 的表达水平对缺血时间非常敏感。对 mRNA 完整性和表达与 PMI 之间的关系有明确的认识，可以使多个 mRNA 作为法医工具用于确定死因，特别是心血管疾病。
