人不同体液特异circRNAs的鉴定、甄选及法医学意义研究

It is of great significance to identify the tissue origin of biological samples in the forensic science, such as the reconstruction of the crime scene. The identification of tissue origin will be a challenge in the complex biological samples, such as degraded biological samples. Circular RNA from exon circularization (circRNA) is widely reported and has a cell-type-specific expression with great stability and a high expression level, which will allow circRNA to be an ideal candidate biomarker for body fluid identification. In this project, we plan to obtain the expression profiling of circRNAs in the peripheral blood, semen, saliva, urine, menstrual blood, and vaginal fluid (a total of six body fluids) by RNA sequencing (RNA-seq) as well as the expression-specific circRNAs in each of them. By assessing their specificity, stability, detection sensitivity, and so on in the body fluid identification, we try to identify 2-3 candidates from body fluid-specific circRNAs, respectively. By adjusting and optimizing the amplification conditions of candidates, we will establish a multiplex detection system for the identification of six body fluids. Also, we will conduct a comprehensive assessment of this detection system including the specificity and stability on a large routine sample size, mixed samples of different body fluids, and old biological samples. Therefore, this study will provide new candidate biomarkers and a novel detection strategy for body fluid identification, which will improve the efficiency and effectiveness of body fluid identification.

鉴定生物性检材的组织来源在犯罪现场重建等中具有重要意义。复杂生物检材，如降解检材等，对组织来源鉴定方法提出了更高要求。外显子来源的环形RNA（circRNA）是最近被广泛报道的一类RNA，具有细胞表达特异性，稳定性好且表达丰富，是理想的体液鉴定候选生物标记。本项目拟通过转录组测序（RNA-seq）鉴定外周血、精液、唾液、尿液、月经血和阴道液共6种体液的circRNA表达谱。通过考察评估各体液特异circRNAs在体液鉴定中的特异性、稳定性、检测敏感性等，分别获得2-3个适合各体液鉴定的候选circRNAs。通过调整优化候选circRNAs的扩增条件，建立一个能鉴定6种体液的复合检测体系，并通过大样本量常规检材以及不同体液的混合检材、陈旧检材对其特异性、稳定性等进行全面评估。该研究的开展，将为体液鉴定提供新的候选标记和检测策略，提高体液鉴定的效率。

鉴定生物性检材的组织来源在犯罪现场重建等中具有重要意义。复杂生物检材，如降解检材等，对组织来源鉴定方法提出了更高要求。本项目首先通过鉴定ALAS2和MMP7两个生物标记的circRNA，发展mRNA和circRNA共检测策略，评估包含circRNA检测在体液鉴定中的效能；结果表明mRNA和circRNA共检测策略提高了生物标记的检测敏感性和生物标记的稳定性。进一步通过筛选获得了6种体液45个生物标记，鉴定其中有14个生物标记含有circRNA表达，并获得了其结构，评估了circRNA表达水平以及包含circRNA检测对生物标记特异性的影响，结果表明包含circRNA检测并不影响生物标记的特异性。最后建立了一个可以同时检测18个生物标记、判别6种体液类型的复合扩增检测体系，研究结构表明该体系具有良好的检测特异性、较高的检测敏感性，对于降解检材和混合检材具有很好的检测效果。总之，本项目为法医体液鉴定提供了一种新的检测方法。