Assessing weaning stress - Relations between enamel hypoplasia, δ18O and δ13C values in human teeth obtained from early modern cemeteries in Wroclaw, Poland

Spatial analysis of the ancient proteome of archeological teeth using mass spectrometry imaging

RATIONALE

Proteins extracted from archaeological bone and teeth are utilised for investigating the phylogeny of extinct and extant species, the biological sex and age of past individuals, as well as ancient health and physiology. However, variable preservation of proteins in archaeological materials represents a major challenge.

METHODS

To better understand the spatial distribution of ancient proteins preserved within teeth, we applied matrix assisted laser desorption/ionisation mass spectrometry imaging (MALDI-MSI) for the first time to bioarchaeological samples to visualise the intensity of proteins in archaeological teeth thin sections. We specifically explored the spatial distribution of four proteins (collagen type I, of which the chains alpha-1 and alpha-2, alpha-2-HS-glycoprotein, haemoglobin subunit alpha and myosin light polypeptide 6).

RESULTS

We successfully identified ancient proteins in archaeological teeth thin sections using mass spectrometry imaging. The data are available via ProteomeXchange with identifier PXD038114. However, we observed that peptides did not always follow our hypotheses for their spatial distribution, with distinct differences observed in the spatial distribution of several proteins, and occasionally between peptides of the same protein.

CONCLUSIONS

While it remains unclear what causes these differences in protein intensity distribution within teeth, as revealed by MALDI-MSI in this study, we have demonstrated that MALDI-MSI can be successfully applied to mineralised bioarchaeological tissues to detect ancient peptides. In future applications, this technique could be particularly fruitful not just for understanding the preservation of proteins in a range of archaeological materials, but making informed decisions on sampling strategies and the targeting of key proteins of archaeological and biological interest.

Hazardous elements in urban cemeteries and possible architectural design solutions for a more sustainable environment

The general objective of this study is to identify the presence of hazardous elements in the soils of five urban cemeteries in the city of Passo Fundo, in southern Brazil, and to design solutions (architecturally) for future cemeteries to be more sustainable by mitigating toxicological risks to the population residing in the area. A total of 250 soil samples were obtained from points within the cemeteries and in areas surrounding the two oldest cemeteries at a distance of up to 400 m. Twelve architects who design cemeteries primarily focused on sustainability were interviewed, and presented their suggestions for sustainable urban cemetery design. The Building Information Modeling (BIM) computer modeling system was utilized to present a visual representation of suggested architectural features by these architects. The concentration of Pb in the vicinity of cemeteries deserves special attention, as concentrations of this neurotoxin exceed the federal limits set by Brazil. Soil Pb values were found to exceed the limit of 72 mg kg-1 up to a distance of 400 m from the walls of cemeteries A and B, indicating the presence of a danger to human health even at greater distances. This manuscript highlights construction features that enable future burial structures to adequately mitigate the very real problem of contaminants entering the environment from current cemetery design. Two-thirds of the technicians interviewed for this manuscript, each of whom specialize in Brazilian cemetery design, highlighted the importance of revitalizing urban vegetation both when constructing and revitalizing urban vertical cemeteries.