Oxidative stress in experimental traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of death and disability among the young population in the industrialized world. The injury consists of immediate damage to the brain tissue, followed by a secondary response involving inflammation and oxidative stress. No pharmacological treatment is effective and the physical and inflammatory mechanisms are insufficiently understood. Considerable variability exists in the clinical outcome after TBI. Genetic factors have been implicated to affect the posttraumatic inflammatory response. This study was undertaken to explore a possible impact of genetic polymorphism in oxidative stress reactions after experimental TBI, and to determine possible effects of direct physical forces on inflammatory cell activation. TBI was induced using mild focal and penetrating focal brain injury models, in inbred and outbred rat strains and male and female rats. Genetic susceptibility to inflammation in the central nervous system (CNS) was found to be associated to the redox active enzymes iNOS and MnSOD in inflammatory cells, but was not associated with increased neuronal degeneration at 24h. The genetic regulation of oxidative stress vulnerability was corroborated in primary neuronal cultures, where neurons primed in an environment of high susceptibility to inflammatory activity had increased compensatory antioxidative enzymes MnSOD and PRDX5, leading to reduced lipid peroxidation, nitrosylation and degeneration. Humoral stimulation was necessary for iNOS induction in neurons. Gender also affected the inflammatory response. The inflammatory enzyme COX-2 was increased in males compared to females at 24h and 72h and correlated with increased apoptosis at 24h in males, but not neuronal degeneration, astrogliosis, microgliosis or nitrosylation. Direct physical force by shock wave trauma caused an inflammatory activation in two different macrophage cell lines, which did not include iNOS or NO increase. Energy transfer by trauma activated the macrophages directly without humoral mediators, comprising a novel activation mechanism of macrophages. Posttraumatic treatment with the antioxidative compound N-acetylcysteine amide reduced neuronal degeneration, increased MnSOD at 24h and reduced apoptosis at 2h. Levels of migrating macrophages/activated microglia, iNOS, nitrosylation or NFkB were not affected. In summary, our findings demonstrated that genetic factors regulated oxidative stress related inflammation after TBI, macrophages were activated by direct physical forces and an antioxidative drug provided neuroprotection after TBI. Susceptibility to CNS inflammation and oxidative stress are interrelated and should be considered when evaluating novel antioxidative treatments

Systematic studies on the determination of Hg-labelled proteins using laser ablation-ICPMS and isotope dilution analysis

A method was developed for the precise and accurate determination of ovalbumin labelled with p-hydroxy-mercuribenzoic acid (pHMB) using polyacrylamide gel electrophoresis with ns-laser ablation-inductively coupled plasma mass spectrometry. Following systematic optimisation of the ablation process in terms of detection sensitivity, two different quantification strategies were applied: external calibration using standards of the derivatized protein after 13C+ normalization and, as a proof of concept, label-specific isotope dilution analysis (IDA) using pHMB enriched in the isotope 199Hg. Due to the inhomogeneous distribution of the protein within the gel bands, it could be demonstrated that the IDA approach was superior in terms of precision and accuracy. Furthermore, it permits a reliable quantification, if more complex separation protocols are applied, as typically occurring analyte loss and degradation can be compensated for as soon as complete mixture of spike and sample is achieved. The estimated limit of detection was 160fmol in the case of ovalbumin. In contrast to earlier studies using metals naturally present in proteins, no loss of mercury was observed during separation under denaturing conditions and other sample preparation steps. Using label-specific IDA, the measured isotope ratios in the gel corresponded to recoveries between 95% and 103

The Neolithic Pitted Ware culture foragers were culturally but not genetically influenced by the Battle Axe culture herders

Abstract: Objectives: In order to understand contacts between cultural spheres in the third millennium BC, we investigated the impact of a new herder culture, the Battle Axe culture, arriving to Scandinavia on the people of the sub-Neolithic hunter-gatherer Pitted Ware culture. By investigating the genetic make-up of Pitted Ware culture people from two types of burials (typical Pitted Ware culture burials and Battle Axe culture-influenced burials), we could determine the impact of migration and the impact of cultural influences. Methods: We sequenced and analyzed the genomes of 25 individuals from typical Pitted Ware culture burials and from Pitted Ware culture burials with Battle Axe culture influences in order to determine if the different burial types were associated with different gene-pools. Results: The genomic data show that all individuals belonged to one genetic population—a population associated with the Pitted Ware culture—irrespective of the burial style. Conclusion: We conclude that the Pitted Ware culture communities were not impacted by gene-flow, that is, via migration or exchange of mates. These different cultural expressions in the Pitted Ware culture burials are instead a consequence of cultural exchange

Genetic continuity, isolation, and gene flow in Stone Age Central and Eastern Europe

Abstract The genomic landscape of Stone Age Europe was shaped by multiple migratory waves and population replacements, but different regions do not all show the same patterns. To refine our understanding of the population dynamics before and after the dawn of the Neolithic, we generated and analyzed genomic sequence data from human remains of 56 individuals from the Mesolithic, Neolithic and Eneolithic across Central and Eastern Europe. We found that Mesolithic European populations formed a geographically widespread isolation-by-distance zone ranging from Central Europe to Siberia, which was already established 10 000 years ago. We also found contrasting patterns of population continuity during the Neolithic transition: people around the lower Dnipro Valley region, Ukraine, showed continuity over 4 000 years, from the Mesolithic to the end of Neolithic, in contrast to almost all other parts of Europe where population turnover drove this cultural change, including vast areas of Central Europe and around the Danube River

Genomic and strontium isotope variation reveal immigration patterns in a Viking Age town

The impact of human mobility on the northern European urban populations during the Viking and Early Middle Ages and its repercussions in Scandinavia itself are still largely unexplored. Our study of the demographics in the final phase of the Viking era is the first comprehensive multidisciplinary investigation that includes genetics, isotopes, archaeology, and osteology on a larger scale. This early Christian dataset is particularly important as the earlier common pagan burial tradition during the Iron Age was cremation, hindering large-scale DNA analyses. We present genome-wide sequence data from 23 individuals from the 10th to 12th century Swedish town of Sigtuna. The data revealed high genetic diversity among the early urban residents. The observed variation exceeds the genetic diversity in distinct modern-day and Iron Age groups of central and northern Europe. Strontium isotope data suggest mixed local and non-local origin of the townspeople. Our results uncover the social system underlying the urbanization process of the Viking World of which mobility was an intricate part and was comparable between males and females. The inhabitants of Sigtuna were heterogeneous in their genetic affinities, probably reflecting both close and distant connections through an established network, confirming that early urbanization processes in northern Europe were driven by migration

Genomic Analyses of Pre-European Conquest Human Remains from the Canary Islands Reveal Close Affinity to Modern North Africans

The origins and genetic affinity of the aboriginal inhabitants of the Canary Islands, commonly known as Guanches, are poorly understood. Though radiocarbon dates on archaeological remains such as charcoal, seeds, and domestic animal bones suggest that people have inhabited the islands since the 5th century BCE, it remains unclear how many times, and by whom, the islands were first settled. Previously published ancient DNA analyses of uniparental genetic markers have shown that the Guanches carried common North African Y chromosome markers (E-M81, E-M78, and J-M267) and mitochondrial lineages such as U6b, in addition to common Eurasian haplogroups. These results are in agreement with some linguistic, archaeological, and anthropological data indicating an origin from a North African Berber-like population. However, to date there are no published Guanche autosomal genomes to help elucidate and directly test this hypothesis. To resolve this, we generated the first genome-wide sequence data and mitochondrial genomes from eleven archaeological Guanche individuals originating from Gran Canaria and Tenerife. Five of the individuals (directly radiocarbon dated to a time transect spanning the 7th–11th centuries CE) yielded sufficient autosomal genome coverage (0.21× to 3.93×) for population genomic analysis. Our results show that the Guanches were genetically similar over time and that they display the greatest genetic affinity to extant Northwest Africans, strongly supporting the hypothesis of a Berber-like origin. We also estimate that the Guanches have contributed 16%–31% autosomal ancestry to modern Canary Islanders, here represented by two individuals from Gran Canaria

Bioarchaeological evidence of one of the earliest Islamic burials in the Levant

Abstract: The Middle East plays a central role in human history harbouring a vast diversity of ethnic, cultural and religious groups. However, much remains to be understood about past and present genomic diversity in this region. Here we present a multidisciplinary bioarchaeological analysis of two individuals dated to the late 7th and early 8th centuries, the Umayyad Era, from Tell Qarassa, an open-air site in modern-day Syria. Radiocarbon dates and burial type are consistent with one of the earliest Islamic Arab burials in the Levant. Interestingly, we found genomic similarity to a genotyped group of modern-day Bedouins and Saudi rather than to most neighbouring Levantine groups. This study represents the genomic analysis of a secondary use site with characteristics consistent with an early Islamic burial in the Levant. We discuss our findings and possible historic scenarios in the light of forces such as genetic drift and their possible interaction with religious and cultural processes (including diet and subsistence practices)

Four millennia of Iberian biomolecular prehistory illustrate the impact of prehistoric migrations at the far end of Eurasia

Population genomic studies of ancient human remains have shown how modern-day European population structure has been shaped by a number of prehistoric migrations. The Neolithization of Europe has been associated with large-scale migrations from Anatolia, which was followed by migrations of herders from the Pontic steppe at the onset of the Bronze Age. Southwestern Europe was one of the last parts of the continent reached by these migrations, and modern-day populations from this region show intriguing similarities to the initial Neolithic migrants. Partly due to climatic conditions that are unfavorable for DNA preservation, regional studies on the Mediterranean remain challenging. Here, we present genome-wide sequence data from 13 individuals combined with stable isotope analysis from the north and south of Iberia covering a four-millennial temporal transect (7,500–3,500 BP). Early Iberian farmers and Early Central European farmers exhibit significant genetic differences, suggesting two independent fronts of the Neolithic expansion. The first Neolithic migrants that arrived in Iberia had low levels of genetic diversity, potentially reflecting a small number of individuals; this diversity gradually increased over time from mixing with local hunter-gatherers and potential population expansion. The impact of post-Neolithic migrations on Iberia was much smaller than for the rest of the continent, showing little external influence from the Neolithic to the Bronze Age. Paleodietary reconstruction shows that these populations have a remarkable degree of dietary homogeneity across space and time, suggesting a strong reliance on terrestrial food resources despite changing culture and genetic make-up