Intelligent use of age information from post-translational protein modifications and DNA methylation: A molecular “tool kit” for a wide variety of requirements of post-mortem age estimation

• Applicants: Dr. Jana Naue; Professorin Dr. Stefanie Ritz
• Subject Area: Toxicology, Laboratory Medicine
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 465712281

Age estimation is a highly relevant topic in forensic sciences, the importance of which has grown in times of migration and flight; this also applies to the post-mortem age estimation for the identification of primarily unknown corpses.Methods of age estimation are based on the examination of parameters that change with increasing age. Conventional methods use morphologically detectable age changes. However, due to the complexity of aging, the estimated “morphological age” in adulthood can deviate considerably from the chronological age. In addition, advanced post-mortem changes or special post-mortem situations (e.g. body parts) can also limit the applicability of methods. The identification and description of “molecular clocks” (post-translational protein modifications, DNA methylation) opened up new possibilities for the development of methods for age estimation. So far, these approaches have been used independently of one another. Their combination promises a better recording of highly complex aging processes and thus the possibility of developing optimized age estimation methods for a wide variety of scenarios in forensic practice.The aim of the planned project is the intelligent use and connection of both approaches to develop a repertoire of methods (“toolbox”) from which - depending on the available tissue - the most optimal approach can be selected.To develop a system of such models for age estimation in various scenarios of forensic practise, a comprehensive data set on 3 molecular clocks (accumulation of D-aspartic acid, accumulation of pentosidine, DNA-methylation) in 4 decay-resistent tissues (bone, tendon, intervertebral disc, epiglottis) will be collected. For diverse constellations of available tissues and markers, models will be trained and evaluated, which will allow age predictions based on the given tissue-marker combination in new, individual cases.From this approach, we not only expect new, broadly applicable methods for age estimation under various postmortem conditions, but also an optimized accuracy of age estimation. For the first time, several protein biomarkers as well as epigenetic markers of aging are collected from different tissues of a large number of individuals. The resulting data set will not only be of interest in light of the forensic topic „age estimation“, but will also provide important insights into molecular aging processes.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr. Simon Eickhoff