129 research outputs found
Archaeological occurrences of terrestrial herpetofauna in the insular Caribbean: cultural and biological significance
Although the importance of the archaeological record for addressing questions of biodiversity is gaining ground, its relevance for describing past faunal communities is still under-exploited, particularly for the most under-documented areas and species. Among the most poorly documented taxa are reptiles and amphibians, which are rarely studied in detail in the archaeological record, even in tropical areas where most of these species occur today. Here I evaluate the archaeological and paleontological significance of reptiles and amphibians from the Indigenous archaeological record of the insular Caribbean. Quantitative (bone counts) and qualitative (taxonomic identification) analyses allow researchers to discuss the role of herpetofauna in the subsistence strategies of Indigenous populations as well as their interest for assessing past insular biodiversity. This overview sheds light on both the poor representation of herpetofaunal taxa in Caribbean archaeological deposits and trends in the potential exploitation of reptiles and amphibians by Indigenous populations. In terms of paleoecology, the presented results reveal strong regional differences in the quality and density of data as well as the inadequacy of available archaeofaunal data for addressing questions of past biodiversity.1. Introduction 2. Regional setting 2.1. The insular Caribbean: a highly diverse set of islands 2.2. The past human occupation of the Caribbean 2.3. Modern Caribbean herpetofauna 3. Material and methods 3.1. Caribbean zooarchaeological quantitative and qualitative data 3.2. Statistical analyses 4. Results 4.1. The place of herpetofauna in indigenous archaeofaunal assemblages 4.2 Herpetofauna taxa identified in the assemblages 5. Discussion 5.1. Trends in the exploitation of herpetofauna by the indigenous 5.2. Herpetofaunal taxonomic diversity in the Caribbean archaeological record 5.3. Occurrence and zooarchaeological data regarding the different taxa 5.4. Is the Caribbean archaeological record relevant for addressing questions of biodiversity? 6. Conclusio
P479Extracellular S100A4 induces arterial smooth muscle cell activation in a RAGE-dependent manner
Background: It has been proposed that smooth muscle cells (SMCs) from the arterial wall are heterogeneous and that only a subset of medial SMCs are prone to accumulate into the intima leading to atheromatous plaque formation. We isolated 2 distinct SMC phenotypes from porcine coronary artery: spindle-shaped (S) and rhomboid (R). Biological features of R-SMCs (i.e. enhanced proliferative and migratory activities as well as poor level of differentiation) explain their capacity to accumulate into the intima. We identified S100A4 as being a marker of the R-SMCs in vitro and of intimal SMCs, both in pig and human. S100A4 is a Ca2+-binding protein that can also be secreted; it has extracellular functions probably via the receptor for advanced glycation end products (RAGE). Purpose: Explore the role of S100A4 in SMC phenotypic change, a phenomenon characteristic of atherosclerotic plaque formation. Methods and Results: Transfection of a human S100A4-containing plasmid in spindle-shaped (S) SMCs (devoid of S100A4) led to approximately 10% of S100A4-overexpressing SMCs, S100A4 release, and a transition towards a R-phenotype of the whole SMC population. Furthermore treatment of S-SMCs with S100A4-rich conditioned medium collected from S100A4-transfected S-SMCs induced a transition towards a phenotype typical of the R-SMCs, which was associated with decreased SMC differentiation markers, increased proliferation and migration, as well as induced proteolytic activity through activation of urokinase-type plasminogen activator (uPA), matrix metalloproteinases (MMP-1,-2, -3, and -9) and their inhibitors (TIMP-1). Furthermore, extracellular S100A4 yielded activation of NF-kB in a RAGE-dependent manner. Blockade of extracellular S100A4 in R-SMCs with S100A4 neutralizing antibody induced a transition from R- to S-phenotype, decreased proliferative activity and upregulation of SMC differentiation markers. In contrast, silencing of S100A4 mRNA in R-SMCs did not change the level of extracellular S100A4 nor SMC morphology in spite of decreased proliferative activity. Conclusions: Our results indicate that SMC phenotypic changes are essentially dependent on extracellular S100A4 activity. It could be a new target to prevent SMC accumulation during atherosclerosis and restenosi
304Nuclear targeting apelin induces phenotypic transition of vascular smooth muscle cells
Background: Apelin, and its receptor APJ, are a peptidic system playing a crucial role in vascular diseases. However, the role of apelin in atherogenesis and smooth muscle cell (SMC) proliferation remains unclear. We isolated 2 distinct SMC phenotypes from porcine coronary artery: spindle-shaped (S) and rhomboid (R). Biological features of R-SMCs (i.e. enhanced proliferative and migratory activities as well as poor level of differentiation) explain their capacity to accumulate into the intima. S100A4 is a marker of R-SMCs in vitro and of intimal SMCs, both in pig and human. S100A4 is a Ca2+-binding protein that can also be secreted; it has extracellular functions probably via the receptor for advanced glycation end products (RAGE). Purpose: Investigate the effects of apelin on SMC phenotypic transition and S100A4 expression and release. Methods and Results: We observed that apelin was highly expressed in R-SMCs particularly in their nucleus. P-SORT software analysis of preproapelin sequence suggested that N-terminal truncated apelin may target the nucleus, and we confirmed this in SMCs by overexpression of mutated preproapelin-His-tag. Transfection of mutated preproapelin-His-tag encoding plasmid in differentiated S-SMCs induced a transition towards a R-phenotype associated with increased proliferative activity, downregulation of SMC differentiation markers (i.e. alpha-smooth muscle actin), and increased nuclear expression and release of S100A4. In contrast, transfection of S-SMCs with wild type preproapelin-His-tag encoding plasmid did not induce nuclear targeting of Apelin or S100A4, and did not change the S-phenotype. Stimulation of S-SMCs with PDGF-BB, known to induce a transition to the R-phenotype, yielded nuclear targeting of both apelin and S100A4. In vivo, Apelin was expressed in SMC nuclei of stent-induced intimal thickening while its expression in the media was mainly cytoplasmic. Conclusions: Our results suggest that nuclear targeting of apelin in SMCs acts on S100A4 expression and release, cell proliferation and differentiation. The pathophysiological consequences of this retargeting could be instrumental in the understanding of artherosclerosi
Multi-taxa neo-taphonomic analysis of bone remains from barn owl pellets and cross-validation of observations: a case study from Dominica (Lesser Antilles)
Paleo- and neo-taphonomic analyses of bone assemblages rarely consider all the occurring taxa in a single study and works concerning birds of prey as accumulators of microvertebrate bone remains mostly focus on small mammals such as rodents and soricomorphs. However, raptors often hunt and consume a large range of taxa, including vertebrates such as small mammals, fishes, amphibians, squamates and birds. Bone remains of all these taxonomic groups are numerous in many paleontological and archaeological records, especially in cave deposits. To better characterize the predators at the origin of fossil and sub-fossil microvertebrate accumulations and the taphonomic history of the deposit, it is thus mandatory to conduct global and multi-taxa taphonomic approaches. The aim of this study is to provide an example of such a global approach through the investigation of a modern bone assemblage from a sample of pellets produced by the Lesser Antillean Barn Owl (Tyto insularis) in the island of Dominica. We propose a new methodology that allows us to compare different taxa (rodents, bats, squamates and birds) and to experiment with a cross-validation process using two observers for each taxonomic group to test the reliability of the taphonomic observations.1. Introduction 2. Materials and Methods 2.1. Owl Pellets Sampling 2.2. Prey Identification 2.3. Taphonomic Analysis 2.3.1. Anatomical Representation 2.3.2. Fragmentation 2.3.3. Surface Modifications 2.3.4. Size/Weight Classes of Preys 2.4. Cross-Validation of Observations 3. Results 3.1. Faunal Spectrum 3.2. Anatomical Representation 3.3. Fragmentation 3.4. Modifications of Bone Surface 4. Discussion 4.1. Diet of Tyto Insularis in Dominica 4.2. Taphonomic Impact of Tyto Insularis on Small Vertebrate Bone Assemblage 4.2.1. Remarks on the Size/Weight Classes of Preys 4.2.2. Anatomical Representation 4.2.3. Fragmentation 4.2.4. Digestion 4.3. Degree of Inter-Observer Differences and Potential Outcomes 4.4. Towards an “Inter-Taxa Calibration” 5. Conclusion
Identifying the anti-inflammatory response to lipid lowering therapy: a position paper from the working group on atherosclerosis and vascular biology of the European Society of Cardiology
Dysregulated lipid metabolism induces an inflammatory and immune response leading to atherosclerosis. Conversely, inflammation may alter lipid metabolism. Recent treatment strategies in secondary prevention of atherosclerosis support beneficial effects of both anti-inflammatory and lipid-lowering therapies beyond current targets. There is a controversy about the possibility that anti-inflammatory effects of lipid-lowering therapy may be either independent or not of a decrease in low-density lipoprotein cholesterol. In this Position Paper, we critically interpret and integrate the results obtained in both experimental and clinical studies on anti-inflammatory actions of lipid-lowering therapy and the mechanisms involved. We highlight that: (i) besides decreasing cholesterol through different mechanisms, most lipid-lowering therapies share anti-inflammatory and immunomodulatory properties, and the anti-inflammatory response to lipid-lowering may be relevant to predict the effect of treatment, (ii) using surrogates for both lipid metabolism and inflammation as biomarkers or vascular inflammation imaging in future studies may contribute to a better understanding of the relative importance of different mechanisms of action, and (iii) comparative studies of further lipid lowering, anti-inflammation and a combination of both are crucial to identify effects that are specific or shared for each treatment strategy
Endothelial dysfunction in COVID-19: a position paper of the ESC Working Group for Atherosclerosis and Vascular Biology, and the ESC Council of Basic Cardiovascular Science
The COVID-19 pandemic is an unprecedented healthcare emergency causing mortality and illness across the world. Although primarily affecting the lungs, the SARS-CoV-2 virus also affects the cardiovascular system. In addition to cardiac effects, e.g. myocarditis, arrhythmias, and myocardial damage, the vasculature is affected in COVID-19, both directly by the SARS-CoV-2 virus, and indirectly as a result of a systemic inflammatory cytokine storm. This includes the role of the vascular endothelium in the recruitment of inflammatory leucocytes where they contribute to tissue damage and cytokine release, which are key drivers of acute respiratory distress syndrome (ARDS), in disseminated intravascular coagulation, and cardiovascular complications in COVID-19. There is also evidence linking endothelial cells (ECs) to SARS-CoV-2 infection including: (i) the expression and function of its receptor angiotensin-converting enzyme 2 (ACE2) in the vasculature; (ii) the prevalence of a Kawasaki disease-like syndrome (vasculitis) in COVID-19; and (iii) evidence of EC infection with SARS-CoV-2 in patients with fatal COVID-19. Here, the Working Group on Atherosclerosis and Vascular Biology together with the Council of Basic Cardiovascular Science of the European Society of Cardiology provide a Position Statement on the importance of the endothelium in the underlying pathophysiology behind the clinical presentation in COVID-19 and identify key questions for future research to address. We propose that endothelial biomarkers and tests of function (e.g. flow-mediated dilatation) should be evaluated for their usefulness in the risk stratification of COVID-19 patients. A better understanding of the effects of SARS-CoV-2 on endothelial biology in both the micro- and macrovasculature is required, and endothelial function testing should be considered in the follow-up of convalescent COVID-19 patients for early detection of long-term cardiovascular complications
Biomechanical factors in atherosclerosis: mechanisms and clinical implications†
Blood vessels are exposed to multiple mechanical forces that are exerted on the vessel wall (radial, circumferential and longitudinal forces) or on the endothelial surface (shear stress). The stresses and strains experienced by arteries influence the initiation of atherosclerotic lesions, which develop at regions of arteries that are exposed to complex blood flow. In addition, plaque progression and eventually plaque rupture is influenced by a complex interaction between biological and mechanical factors—mechanical forces regulate the cellular and molecular composition of plaques and, conversely, the composition of plaques determines their ability to withstand mechanical load. A deeper understanding of these interactions is essential for designing new therapeutic strategies to prevent lesion development and promote plaque stabilization. Moreover, integrating clinical imaging techniques with finite element modelling techniques allows for detailed examination of local morphological and biomechanical characteristics of atherosclerotic lesions that may be of help in prediction of future events. In this ESC Position Paper on biomechanical factors in atherosclerosis, we summarize the current ‘state of the art' on the interface between mechanical forces and atherosclerotic plaque biology and identify potential clinical applications and key questions for future researc
Translational opportunities of single-cell biology in atherosclerosis
The advent of single-cell biology opens a new chapter for understanding human biological processes and for diagnosing, monitoring, and treating disease. This revolution now reaches the field of cardiovascular disease (CVD). New technologies to interrogate CVD samples at single-cell resolution are allowing the identification of novel cell communities that are important in shaping disease development and direct towards new therapeutic strategies. These approaches have begun to revolutionize atherosclerosis pathology and redraw our understanding of disease development. This review discusses the state-of-the-art of single-cell analysis of atherosclerotic plaques, with a particular focus on human lesions, and presents the current resolution of cellular subpopulations and their heterogeneity and plasticity in relation to clinically relevant features. Opportunities and pitfalls of current technologies as well as the clinical impact of single-cell technologies in CVD patient care are highlighted, advocating for multidisciplinary and international collaborative efforts to join the cellular dots of CVD
Novel methodologies for biomarker discovery in atherosclerosis
Identification of subjects at increased risk for cardiovascular events plays a central role in the worldwide efforts to improve prevention, prediction, diagnosis, and prognosis of cardiovascular disease and to decrease the related costs. Despite their high predictive value on population level, traditional risk factors fail to fully predict individual risk. This position paper provides a summary of current vascular biomarkers other than the traditional risk factors with a special focus on the emerging −omics technologies. The definition of biomarkers and the identification and use of classical biomarkers are introduced, and we discuss the limitations of current biomarkers such as high sensitivity C-reactive protein (hsCRP) or N-terminal pro-brain natriuretic peptide (NT-proBNP). This is complemented by circulating plasma biomarkers, including high-density lipoprotein (HDL), and the conceptual shift from HDL cholesterol levels to HDL composition/function for cardiovascular risk assessment. Novel sources for plasma-derived markers include microparticles, microvesicles, and exosomes and their use for current omics-based analytics. Measurement of circulating micro-RNAs, short RNA sequences regulating gene expression, has attracted major interest in the search for novel biomarkers. Also, mass spectrometry and nuclear magnetic resonance spectroscopy have become key complementary technologies in the search for new biomarkers, such as proteomic searches or identification and quantification of small metabolites including lipids (metabolomics and lipidomics). In particular, pro-inflammatory lipid metabolites have gained much interest in the cardiovascular field. Our consensus statement concludes on leads and needs in biomarker research for the near future to improve individual cardiovascular risk predictio
Translational opportunities of single-cell biology in atherosclerosis
The advent of single-cell biology opens a new chapter for understanding human biological processes and for diagnosing, monitoring, and treating disease. This revolution now reaches the field of cardiovascular disease (CVD). New technologies to interrogate CVD samples at single-cell resolution are allowing the identification of novel cell communities that are important in shaping disease development and direct towards new therapeutic strategies. These approaches have begun to revolutionize atherosclerosis pathology and redraw our understanding of disease development. This review discusses the state-of-the-art of single-cell analysis of atherosclerotic plaques, with a particular focus on human lesions, and presents the current resolution of cellular subpopulations and their heterogeneity and plasticity in relation to clinically relevant features. Opportunities and pitfalls of current technologies as well as the clinical impact of single-cell technologies in CVD patient care are highlighted, advocating for multidisciplinary and international collaborative efforts to join the cellular dots of CVD
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