The relationship between the degradation of five RNAs and early PMI in brain tissue of rats with different causes of death
10.13618/j.issn.1001-5728.2024.04.014
- VernacularTitle:不同死亡原因大鼠脑组织5种RNA降解与早期PMI的相关性
- Author:
Shifa HUANG
1
;
Yue WU
Author Information
1. 青海大学,青海 西宁 810003
- Keywords:
Forensic pathology;
RNA;
Internal reference gene;
Time of death;
Cause of death
- From:
Chinese Journal of Forensic Medicine
2024;39(4):450-456
- CountryChina
- Language:Chinese
-
Abstract:
Objective To establish a mathematical model of early PMI and RNA △Cq under different causes of death,which provides a reference for early PMI inference under the condition of changing causes of death.Methods Thirty adult male SD rats with SPF level were randomly divided into 5 groups with 6 animals in each group(Death by carotid artery major hemorrhage;Death by strangle;Death by drown;Death by organophosphorus pesticides;Death by CO poisoning).The rats were placed in a constant temperature and humidity incubator at 20℃and 55%humidity after death.RNA was extracted from brain tissue at 7 time points within 0～24 h postmortem.The Cq values of five RNA(β-actin,GAPDH,miR-9,miR-124,miR-125b)were measured at each time point.QBase+V(3.4)software geNorm program was used to select the internal parameters.The correlation between early PMI and RNA △Cq was analyzed by SAS 9.4 software,and a mathematical model was established.Another 15 adult male SD rats with SPF level were randomly divided into 5 groups.The RNA from brain tissue were collected at 10 h and 20 h after death for back-inference verification.Results(1)The fluorescence of miR-124 could not be captured in this experimental system,and this gene could not be used as a candidate gene in this experimental system.(2)The stability of the four genes(β-actin,GAPDH,miR-9 and miR-125b)in rat brain tissue varied under different conditions of death.Using SAS 9.4 software,the correlation analysis were conducted between early postmortem interval(PMI)and RNA △Cq values,and the mathematical models were set up for early PMI estimation.Conclusion(1)The causes of death can affect the degradation of RNA in postmortem brain tissue of rats,and different reference genes should be selected under different causes of death.(2)The mathematical model established under this experimental system can provide reference for early postmortem PMI inference of different causes of death.
