急性心肌缺血线粒体MitomiRs表达谱改变及法医学应用与基础研究

Sudden death is the most common cause in forensic application, and sudden cardiac death attributes 60~80% of them. Due to very short process of sudden death, it is difficult to find typical histopathological changes, and also brings great difficulties to the forensic identification. Therefore, it is urgent to find new specific biomarker for acute myocardial ischemia, which also provides a new way for forensic identification of sudden cardiac death. In this study, we collect the cases of sudden cardiac death and the non myocardial ischemic death cases (traffic accident death) as the research objects, which is a kinds of the normal / disease control methods; choose the mitomiRs which have been demonstrated that they are closely related to mitochondrial functions as the object of observation; screen and compare the expression of the mitomiRs between above two groups by microRNA Chips, and analysis by Biostatistics analysis to select out a group of sudden cardiac death related mitomiRs in Chinese. At last, we will further to demonstrate the identification efficence in forensic application by real-time PCR to provide a new molecular diagnostic method for the sudden cardiac death in forensic medicine.

猝死是法医学实践中常见的死亡原因，而心源性猝死约占其中的60~80%。猝死患者由于死亡过程极短，心肌中难以发现典型的组织病理学改变，给法医学鉴定带来极大困难。因此，亟待寻找到新的特异性早期心肌缺血分子标记，为心源性猝死的法医学鉴定提供新的途径。本研究收集法医学实际检案中原因不明的心源性猝死案例及非心肌缺血死亡案例（交通事故死亡）作为研究对象，采用正常/疾病对照的研究手段，选择已证实的与线粒体功能密切相关的MitomiRs为观察对象，利用芯片技术对MitomiRs在心源性猝死案例组和非心肌缺血死亡案例组的表达进行筛选、比对，对其表达差异进行生物统计学分析，筛选出与中国人急性心肌缺血发生密切相关的MitomiRs；同时，利用qRT-PCR技术对具有显著性表达差异的MitomiRs指标在法医学检案中进行验证，进一步对其可靠性、进行验证，为法医学死因诊断提供新的分子诊断方法。

目的：微小RNA(microRNA,miRNA)是一类在转录后水平对mRNA进行负调控的关键调控因子。本研究旨在运用microRNA芯片技术，筛选出心源性猝死、窒息、严重颅脑损伤、失血性休克等死因下差异表达的microRNA，从分子生物学角度阐述不同死因下心肌组织的microRNA表达量的变化，最终为上述死因案件的鉴定提供生物信息学依据。对象：实验动物模型及司法部司法鉴定科学技术研究院2016年受理的上海及全国各地区法医学检案人的心肌组织。方法：建立心肌缺血、窒息、严重颅脑损伤、失血性休克等常见死因下的大鼠模型，运用microRNA芯片技术，针对性的分析不同死因下，大鼠心肌的microRNA表达量的变化，筛选差异性表达的microRNA。利用TargetScan和miRDB数据库预测差异表达microRNA的靶基因，使用R语言中的clusterProfiler包对靶基因进行GO和KEGG数据库注释，进而通过Cytoscape软件构建miRNA-mRNA的调控网络。同时，对实际法医学检案中死因为心源性猝死的心肌组织，运用microRNA芯片技术，筛选出差异表达的microRNA。 结论：通过运用microRNA芯片技术对不同死因下的大鼠进行死因判别，筛选出了具有差异表达的microRNA，同时，对死因为心源性猝死的人体样本，也筛选出了具有差异表达的microRNA;最终为不同死因下的案件的鉴定提供可能的microRNA指标。