Mitochondrial DNA patterns in the Iberian Northern plateau: Population dynamics and substructure of the Zamora province

Several studies have shown the importance of recent events in the configuration of the genetic landscape of a specific territory. In this context, due to the phenomena of repopulation and demographic fluctuations that took place in recent centuries, the Iberian Northern plateau is a very interesting case study. The main aim of this work is to check if recent population movements together with existing boundaries (geographical and administrative) have influenced the current genetic composition of the area. To accomplish this general purpose, mitochondrial DNA variations of 214 individuals from a population located in the Western region of the Iberian Northern plateau (the province of Zamora) were analyzed. Results showed a typical Western European mitochondrial DNA haplogroup composition. However, unexpected high frequencies of U5, HV0, and L haplogroups were found in some regions. The analyses of microdifferentiation showed that there are differences between regions, but no geographic substructure organization can be noticed. It can be stated that the differences observed in the genetic pool of the sampled area at regional level results from the mixture of different populations carrying new lineages into this area at different points in history. Am J Phys Anthropol 142:531–539, 2010. © 2010 Wiley‐Liss, Inc.     

The usefulness of caries frequency,depth, and location in determining cariogenicity and past subsistence: A test on early and later agriculturalists from the Peruvian coast

Dental markers have been used to unravel particularities of paleodiet, subsistence, social structure, and health. This article aims to compare oral pathology among four pre‐Columbian groups with different degrees of agricultural and socio‐cultural development but comparable ecological conditions who lived on the coastal desert of Peru. Three of these groups are assigned to distinct phases of the Formative Period (2500–1 BC), a time critical for our understanding of the development of agriculture and social complexity. The fourth group corresponds to the Late Intermediate Period (1000–1470 AD), when agriculture had its apogee and society was highly stratified. In this study we test whether there is an increase (1) in the frequency of carious lesions and (2) in caries depth, and (3) if there is a shift from occlusal to extra‐occlusal caries locations with the development of agriculture. Therefore, we analyze the frequencies of carious lesions and antemortem tooth loss (AMTL), the caries distributions by age, sex, and type of tooth, as well as the tissues affected by, and the location of the carious lesions. Since there are no significant differences in the frequencies of carious lesions and AMTL between the groups, we reject hypothesis 1. In contrast, caries depth does increase, and caries location changes from occlusal to extra‐occlusal sites with agricultural development. However, we can only corroborate hypothesis 2 and 3 when taking into consideration dental wear. Thus, we recommend that caries depth and locations should be used with evaluations of dental wear to reconstruct subsistence in ancient populations. Am J Phys Anthropol 143:75–91, 2010. © 2010 Wiley‐Liss, Inc.     

Characteristics of the rat cardiac sphingolipid pool in two mitochondrial subpopulations

Mitochondrial sphingolipids play a diverse role in normal cardiac function and diseases, yet a precise quantification of cardiac mitochondrial sphingolipids has never been performed. Therefore, rat heart interfibrillary mitochondria (IFM) and subsarcolemmal mitochondria (SSM) were isolated, lipids extracted, and sphingolipids quantified by LC-tandem mass spectrometry. Results showed that sphingomyelin (∼10,000 pmol/mg protein) was the predominant sphingolipid regardless of mitochondrial subpopulation, and measurable amounts of ceramide (∼70 pmol/mg protein) sphingosine, and sphinganine were also found in IFM and SSM. Both mitochondrial populations contained similar quantities of sphingolipids except for ceramide which was much higher in SSM. Analysis of sphingolipid isoforms revealed ten different sphingomyelins and six ceramides that differed from 16- to 24-carbon units in their acyl side chains. Sub-fractionation experiments further showed that sphingolipids are a constituent part of the inner mitochondrial membrane. Furthermore, inner membrane ceramide levels were 32% lower versus whole mitochondria (45 pmol/mg protein). Three ceramide isotypes (C₂₀-, C₂₂-, and C₂₄-ceramide) accounted for the lower amounts. The concentrations of the ceramides present in the inner membranes of SSM and IFM differed greatly. Overall, mitochondrial sphingolipid content reflected levels seen in cardiac tissue, but the specific ceramide distribution distinguished IFM and SSM from each other.     

The N-glycosylation of classical swine fever virus E2 glycoprotein extracellular domain expressed in the milk of goat

Classical swine fever virus (CSFV) outer surface E2 glycoprotein represents an important target to induce protective immunization during infection but the influence of N-glycosylation pattern in antigenicity is yet unclear. In the present work, the N-glycosylation of the E2-CSFV extracellular domain expressed in goat milk was determined. Enzymatic N-glycans releasing, 2-aminobenzamide (2AB) labeling, weak anion-exchange and normal-phase HPLC combined with exoglycosidase digestions and mass spectrometry of 2AB-labeled and unlabeled N-glycans showed a heterogenic population of oligomannoside, hybrid and complex-type structures. The detection of two Man₈GlcNAc₂ isomers indicates an alternative active pathway in addition to the classical endoplasmic reticulum processing. N-acetyl or N-glycolyl monosialylated species predominate over neutral complex-type N-glycans. Asn207 site-specific micro-heterogeneity of the E2 most relevant antigenic and virulence site was determined by HPLC-mass spectrometry of glycopeptides. The differences in N-glycosylation with respect to the native E2 may not disturb the main antigenic domains when expressed in goat milk.     

A peptide based on the pore-forming domain of pro-apoptotic poliovirus 2B viroporin targets mitochondria

Non-structural poliovirus 2B protein induces plasma membrane permeabilization and has been recently implicated in triggering apoptosis via the mitochondrial pathway. Here we describe that the pore-forming P3 peptide, based on the 2B amphipathic domain, translocates through the plasma membrane of culture cells and targets mitochondria. Cell permeabilization by P3 versions of different lengths, together with peptide uptake analyses supported an internalization mechanism dependent on P3 capacity to interact physically with lipid bilayers and establish permeating pores therein. Internalized P3 was found associated with mitochondria, but contrary to the parental 2B protein, the short peptide did not affect the morphology or cell distribution of these organelles, nor induced apoptosis. We conclude that P3 constitutes a mitochondriotropic sequence, which is however devoid of 2B pro-apoptotic activity.     

Metabolic engineering,new antibiotics and biofilm viscoelasticity

In the following highlight we refer to a number of new advances in the field of Biotechnology that address issues relating to the synthesis of new antibiotics, new biocatalysts and matrices in biofilms.     

Biodistribution and long-term fate of silver nanoparticles functionalized with bovine serum albumin in rats

Silver nanocrystals (Ag NCs) hold promising antibiotic and antiviral properties in biological systems. The biodistribution of silver nanostructures injected into animals in vivo is currently unknown, remaining as a fundamental issue for potential therapeutic applications. Here, we injected Ag NCs capped with bovine serum albumin (BSA) in live rats to elucidate their fate in several organs including liver, heart and brain. Very significant accumulations of nanoparticles were confirmed by inductively coupled plasma mass spectroscopy (ICPMS) and transmission electron microscopy (TEM) techniques on the liver and heart. In contrast, the brain tissue did not reveal evidence of particles content. Our results suggest that Ag+ permeated across the blood-brain barrier (BBB), and followed swift clearance from the organ.     

The role of the DNA hypermethylating agent Budesonide in the decatenating activity of DNA topoisomerase II

Catenations between sister chromatids result from DNA replication and must be resolved to ensure proper chromatid segregation in mitosis. Functionally active Topoisomerase II (Topo II), through its mechanism of concerted breaking and rejoining of double stranded DNA, is required to carry out this fundamental process. In previous studies we have shown that modifications in DNA sequence by halogenated pyrimidines and by the demethylating agent 5-azacytidine leads to malfunction of Topo II that results in an increased yield of endorreduplicated cells as a result of segregation failure. In the present work we have evaluated the possible influence of the methylating agent Budesonide to modify the frequency of endoreduplicated cells in AA8 Chinese hamster cell population. Our results seem to indicate that when Budesonide was administered for two consecutive cell cycles did induce an increase in the yield of endoreduplicated cells, as previously observed for the hypomethylating agent 5-azaC. We have also examined the possible relationship between extensive hypermethylation induced by Budesonide in DNA and stabilization of cleavable complexes by m-AMSA. Taken as a whole, our results show that the degree of methylation in DNA correlates with the effectiveness of m-AMSA to stabilize the Topo II-DNA complexes and to induce DNA cleavage. These findings evidence for the first time the functional importance of DNA hyper- and hypomethylation changes as epigenetic factors able to modulate Topo II activity for proper chromosome segregation.     

Dual metabolomics: A novel approach to understanding plant–pathogen interactions

One of the most well-characterised plant pathogenic interactions involves Arabidopsis thaliana and the bacteria Pseudomonas syringae pathovar tomato (Pst). The standard Pst inoculation procedure involves infiltration of large populations of bacteria into plant leaves which means that metabolite changes cannot be readily assigned to the host or pathogen. A plant cell–pathogen co-culture based approach has been developed where the plant and pathogen cells are separated after 12 h of co-culture via differential filtering and centrifugation. Fourier transform infrared (FT-IR) spectroscopy was employed to assess the intracellular metabolomes (metabolic fingerprints) of both host and pathogen and their extruded (extracellular) metabolites (metabolic footprints) under conditions relevant to disease and resistance. We propose that this system will enable the metabolomic profiling of the separated host and pathogen (i.e. ‘dual metabolomics’) and will facilitate the modelling of reciprocal responses.