Thanatotranscriptome Study on Particular Hepatic Genes and Their Correlation With Postmortem Interval in the Presence or Absence of Postmortem Heat Stress

The present work designed to estimate postmortem expression of mRNA of certain hepatic genes in rats in the presence or absence of postmortem heat stress using qRT-PCR technique in correlation to postmortem interval (PMI). Rats were sacrificed and divided into, control group (PMI=0 h), room temperature and heat stressed (41⁰C) groups. In control group, liver samples were collected immediately after death, while in the second and third groups, samples were collected at 1, 3 and 6 hours postmortem. The results showed significant reductions in pro-inflammatory gene transcripts (TNFα and IL-1β) at all-time points compared to control group with an inhibitory effect of postmortem heat stress on expression of TNFα at 1 and 6 h after death. Whereas postmortem expression of genes encode apoptosis was significantly increased at 3 and 6 h postmortem compared to control group. Postmortem heat stress reduced the hepatic expression of Bcl-2 and Caspase-3 at 3 and 6 h of PMI and increased the expression of Caspase-3 at 1 h after death compared to room temperature group. Meanwhile, postmortem hepatic mRNA expression of c-fos was significantly induced after death at 3 and 6 h PMI. Postmortem heat stress significantly reduced c-fos expression at 3 and 6 h after death. Thanatotranscriptome of genes encode inflammation, apoptosis as well as c-fos varied in their correlations to PMI. Additionally, the results showed disparities in the effect of postmortem heat stress according to the studied gene and time.