HIF1α protein and mRNA expression as a new marker for post mortem interval estimation in human gingival tissue

Abstract

Estimating the post mortem interval (PMI) is still a crucial step in Forensic Pathology. Although several methods are available for assessing the PMI, a precise estimation is still quite unreliable and can be inaccurate. The present study aimed to investigate the immunohistochemical distribution and mRNA expression of hypoxia inducible factor (HIF‐1α) in post mortem gingival tissues to establish a correlation between the presence of HIF‐1α and the time since death, with the final goal of achieving a more accurate PMI estimation. Samples of gingival tissues were obtained from 10 cadavers at different PMIs (1–3 days, 4–5 days and 8–9 days), and were processed for immunohistochemistry and quantitative reverse transcription‐polymerase chain reaction. The results showed a time‐dependent correlation of HIF‐1α protein and its mRNA with different times since death, which suggests that HIF‐1α is a potential marker for PMI estimation. The results showed a high HIF‐1α protein signal that was mainly localized in the stratum basale of the oral mucosa in samples collected at a short PMI (1–3 days). It gradually decreased in samples collected at a medium PMI (4–5 days), but it was not detected in samples collected at a long PMI (8–9 days). These results are in agreement with the mRNA data. These data indicate an interesting potential utility of Forensic Anatomy‐based techniques, such as immunohistochemistry, as important complementary tools to be used in forensic investigations.

Changes in gene expression patterns in postmortem human myocardial infarction

“…The lack of a correlation between HIF-1α mRNA expression and the postmortem interval (PMI) is in contrast to the study of Fais et al [ 39 ]. In the cases of PMIs between 1 and 5 days, they reported an increase in HIF-1α mRNA expression in gingival tissue, but when the PMI was longer than 5 days, the HIF-1α expression decreased and was no longer detectable at a PMI of 10 days.…”

“…In the cases of PMIs between 1 and 5 days, they reported an increase in HIF-1α mRNA expression in gingival tissue, but when the PMI was longer than 5 days, the HIF-1α expression decreased and was no longer detectable at a PMI of 10 days. Vennemann and Koppelkamm [ 40 ] stated that the endogenous reference gene GAPDH, which was used by Fais et al [ 39 ], is not a stable reference gene, because it is influenced by hypoxia. The application of three stable reference genes may explain the different results of the present study, which are in accordance with studies of Zhu et al [ 41 ] and Zhao et al [ 42 ], indicating that HIF-1α is a good marker of hypoxia, because its expression is not influenced by gender, age, and PMI.…”

Biomarkers of myocardial injury in rats after cantharidin poisoning: Application for postmortem diagnosis and estimation of postmortem interval

“…Regression analysis results revealed no significant relationship between HIF -1α and PMI within the 168 h after death both in control and experimental. In our present study, we found that the postmortem changes of HIF-1α was consistent with previous study that HIF-1α expression was gradually decreased 4-5 days after death 28 ; However, HIF-1α protein expression as a new marker for PMI estimation in human gingival tissue was confirmed in previous study and the results of the study suggested HIF1α is a promising biomarker for distinguishing deaths that have occurred within 1 week from those that occurred more than 1 week ago; So that much more long-term observation of HIF-1α expression in our further study will help us to explain the difference between previous study and our current study.…”

“…Our present study indicated that postmortem changes of HIF-1α expression was stable both in control and experimental within 72 h after death. The HIF-1α levels in experimental group was decreased 48 h after death and the differences was found in the group of 72 h compared with control; which was supported by the foundings of Fais P et al that HIF-1α expression was gradually decreased in samples collected 4-5 days after death and it was not detected 8-9 days after death 28 . So that the postmortem diagnostic role of HIF-1α need more long-term observation over 168 h after death to more accurate conclusions.…”

Métodos Histoquímicos e Inmunohistoquímicos para la Estimación del Intervalo Postmortem en Tejidos Humanos: Una Revisión

“…Se identificaron estudios entre los años 1994 y 2019, 5 de los cuales han sido publicados en los últimos 3 años. Es destacable que 3 de esos 5 artículos han focalizado su investigación en la aplicación de métodos IHQs en tejidos obtenidos de la cavidad oral (Mazzotti et al;Fais et al, 2018;Charan Gowda et al).…”