Estimating PMI Using Bone Proteomics: An Interview with Noemi Procopio, Part II

As part of “From Sample to Verdict,” LCGC International sat down with Noemi Procopio, who is the Principal Investigator of the "Forens-OMICS" team and a Senior Research Fellow in Forensic Science at the University of Central Lancashire, to talk about her team’s work (1,2). In Part I of our conversation with Procopio, she discussed the development of the Forens-OMICS approach and how her team estimates PMI using metabolomics, proteomics, and metabarcoding. Part II dives deep into post-mortem interval (PMI) estimation and how bone proteomics can be used to accurately estimate PMI.

Will Wetzel: Your research has shown promising results using bone proteomics to estimate PMI beyond six months. What are the key protein markers you’ve identified, and how do they change over time?

Noemi Procopio: We are still in process of looking at some of our data, so I don't have a definitive list of proteins that are the most promising ones. But in general, what we notice is that there are some proteins like those that you are finding in blood and plasma. Those are constantly decreasing over time. These seem to be good biomarkers for postmortem interval estimation because there is blood in blood vessels in bones. Therefore, you will expect to see blood proteins in bones. But then, the longer you leave a bone there, the less abundant these proteins will become because of normal degradation processes.

There are other proteins, like bone matrix proteins, that are equally interesting in the sense that they decrease constantly over time. They may be good indicators with proteomics. It's important to mention that we are not just looking at which proteins are constantly degrading and decreasing in a relative abundance over time. We also want to look at accumulation of post translational protein modifications. So, anything associated, for example, with increased levels of deamidation or oxidation, those modifications are non-enzymatic. Those that don't necessarily need an enzyme and a living cell to take place and to happen, they are accumulating over time. Therefore, an increased abundance of these PTMs can be an equally important biomarker. We are looking at these data into these different ways, and hopefully we're going to come up with a list of definitive biomarkers sooner rather than later.

References

1. Procopio, N. Forens-omics: How a Multi-omic Approach Can Reveal the Mysteries of the Postmortem Interval. The Pathologist 2024, 6. Available at: https://thepathologist.com/issues/2024/articles/nov/forens-omics/ (accessed 2025-07-24)
2. Procopio, N.; Bonicelli, A. From Flesh to Bones: Multi-omics Approaches in Forensic Science. Prot. Sys. Biol. 2024, 24 (12–13), 2200355. DOI: 10.1002/pmic.202200335