The Effects of Inter-Individual Biological Differences and Taphonomic Alteration on Human Bone Protein Profiles: Implications for the Development of PMI/AAD Estimation Methods

Abstract

Bone proteomics studies using animal proxies and skeletonized human remains have delivered encouraging results in the search for potential biomarkers for precise and accurate post-mortem interval (PMI) and the age-at-death (AAD) estimation in medico-legal investigations. At present, however, the effects of inter-individual biological differences and taphonomic alteration on recovered human bone protein profiles are not well understood. This study investigated the human bone proteome in four human body donors studied throughout decomposition outdoors. The effects of ageing phenomena (in vivo and post-mortem), and intrinsic and extrinsic variables on the variety and abundancy of the bone proteome were assessed. Results identified a new potential biomarker for PMI estimation, as well as three potential biomarkers for AAD estimation. The results also suggest that bone mineral density (BMD) may be an important variable affecting the survival and extraction of proteins.

Human Bone Proteomes before and after Decomposition: Investigating the Effects of Biological Variation and Taphonomic Alteration on Bone Protein Profiles and the Implications for Forensic Proteomics

“…In this study, we aimed to investigate the effects of taphonomy and biological variation on the recovery and variability of the human bone proteome and evaluate potential avenues to develop a broadly applicable, standardized method of PMI and AAD estimation in human remains in advanced state of decomposition. 35 The proteomes of anterior midshaft tibia and iliac crest samples from four body donors of known AAD (two buried and two placed in an open pit), taken shortly after death and upon complete skeletonization of the body, were analyzed to investigate (1) whether the previously identified potential biomarkers for PMI and AAD are applicable to human bones with lower PMIs, (2) whether additional potential biomarkers for PMI/AAD estimation could be identified, (3) whether the human bone proteome is subject to inter-skeletal (among different skeletal elements of the same individual), intra-skeletal (within the same skeletal element), and inter-individual (within the same skeletal element among different individuals) variability, and (4) the role decomposition, depositional environment and taphonomy, and season play in bone proteome survival.…”

The Texas State Donated Skeletal Collection at the Forensic Anthropology Center at Texas State

“…An additional important contribution for forensic anthropological research is the accompanying taphonomic data for most of the skeletal remains in the TXSTDSC. This allows researchers to examine the taphonomic influence on morphoscopic and chemical indicators used to develop the biological profile and postmortem interval [13,[26][27][28][29] as well as to distinguish postmortem damage from perimortem trauma. Since some donors provide consent for advanced research, novel and ground-breaking approved studies focused on thermal, ballistic, sharp, and blunt force trauma are possible [30,31].…”