背景:验尸间隔(PMI)的准确估计在法医调查中至关重要。MicroRNAs(miRNA或miRs)是小的非编码RNA,其在细胞核内保持相对稳定,尽管死后改变。
目的:我们评估了三个靶基因(miR-122,miR-133a,和miR-206)使用72只健康成年雄性BALB/c小鼠在10天内的9个不同时间点暴露于两种不同温度(4和21℃)进行PMI估计。
方法:最初,使用基因稳定性分析工具(DeltaCt,最好的守护者,和Genorm)选择最佳参考基因。发现RNU6B是最稳定的内源性对照。随后,miR-122,miR-133a,和miR-206在10天的PMI期内使用心脏进行分析,骨骼肌,肝脏,和脑组织。
结果:在4℃,miR-122水平在第8天和第10天显著降低,在所有组织中,只有肝脏在21℃时出现明显变化。MiR-133a在心脏中随着时间的推移而减少,肌肉,和大脑,在这两个温度下,心脏和肌肉在第8天和第10天都显示出急剧下降。尽管miR-206在4℃时在肌肉和肝脏中的水平随着时间的推移而降低,这些在21℃的大脑中增加,在其他器官中没有表达变化。
结论:总之,miR-122,miR-133a,miR-206是心脏和骨骼肌组织中潜在的PMI标志物。
BACKGROUND: Accurate estimation of post-mortem interval (PMI) is crucial in forensic investigations. MicroRNAs (miRNAs or miRs) are small non-coding RNAs that remain relatively stable within the cell nucleus despite post-mortem changes.
OBJECTIVE: We assessed three target genes (miR-122, miR-133a, and miR-206) for PMI estimation using 72 healthy adult male BALB/c mice exposed to two different temperatures (4 and 21℃) at nine different time points over 10 days.
METHODS: Initially, the stability of the two reference genes (RNU6B and 5 srRNA) was evaluated using gene stability analysis tools (Delta Ct, Best Keeper, and Genorm) to select the optimal reference gene. RNU6B was found to be the most stable endogenous control. Subsequently, the expression patterns of miR-122, miR-133a, and miR-206 were analyzed within a 10-day PMI period using the heart, skeletal muscle, liver, and brain tissues.
RESULTS: At 4℃, miR-122 levels significantly decreased on days 8 and 10 in all tissues, with only the liver showing significant changes at 21℃. MiR-133a decreased over time in the heart, muscles, and brain, showing a dramatic decrease on days 8 and 10 in the heart and muscles at both temperatures. Although miR-206 levels decreased over time in muscles and liver at 4 ℃, these increased in the brain at 21 ℃, with no expression changes in other organs.
CONCLUSIONS: In summary, miR-122, miR-133a, and miR-206 are potential PMI markers in heart and skeletal muscle tissues.