328 research outputs found

    Genetic variation in autophagy-related genes influences the risk and phenotype of Buruli ulcer

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    Introduction Buruli ulcer (BU) is a severe necrotizing human skin disease caused by Mycobacterium ulcerans. Clinically, presentation is a sum of these diverse pathogenic hits subjected to critical immune-regulatory mechanisms. Among them, autophagy has been demonstrated as a cellular process of critical importance. Since microtubules and dynein are affected by mycolactone, the critical pathogenic exotoxin produced by M. ulcerans, cytoskeleton-related changes might potentially impair the autophagic process and impact the risk and progression of infection. Objective Genetic variants in the autophagy-related genes NOD2, PARK2 and ATG16L1 has been associated with susceptibility to mycobacterial diseases. Here, we investigated their association with BU risk, its severe phenotypes and its progression to an ulcerative form. Methods Genetic variants were genotyped using KASPar chemistry in 208 BU patients (70.2% with an ulcerative form and 28% in severe WHO category 3 phenotype) and 300 healthy endemic controls. Results The rs1333955 SNP in PARK2 was significantly associated with increased susceptibility to BU [odds ratio (OR), 1.43; P = 0.05]. In addition, both the rs9302752 and rs2066842 SNPs in NOD2 gee significantly increased the predisposition of patients to develop category 3 (OR, 2.23; P = 0.02; and OR 12.7; P = 0.03, respectively, whereas the rs2241880 SNP in ATG16L1 was found to significantly protect patients from presenting the ulcer phenotype (OR, 0.35; P = 0.02). Conclusion Our findings indicate that specific genetic variants in autophagy-related genes influence susceptibility to the development of BU and its progression to severe phenotypes.The research leading to these results received funding from the Health Services of the Fundação Calouste Gulbenkian under the grant Proc.N°94776 LJ; from the Fundação para a Ciência e Tecnologia (FCT), cofunded by Programa Operacional Regional do Norte (ON.2—O Novo 267 Norte); from the Quadro de Referência Estratégico Nacional (QREN) through the Fundo Europeu de Desenvolvimento Regional (FEDER) and from the Projeto Estratégico – LA 26 – 2013–2014 (PEst-C/SAU/LA0026/2013). JFM received an individual QREN fellowship (UMINHO/BPD/14/2014); CCu and AGF received an individual FCT fellowship (SFRH/BPD/96176/2013 and SFRH/BPD/68547/2010, respectively); and AC received an FCT contract (IF/00735/2014). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

    The frailty index outperforms DNA methylation age and its derivatives as an indicator of biological age

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    The measurement of biological age as opposed to chronological age is important to allow the study of factors that are responsible for the heterogeneity in the decline in health and function ability among individuals during aging. Various measures of biological aging have been proposed. Frailty indices based on health deficits in diverse body systems have been well studied, and we have documented the use of a frailty index (FI(34)) composed of 34 health items, for measuring biological age. A different approach is based on leukocyte DNA methylation. It has been termed DNA methylation age, and derivatives of this metric called age acceleration difference and age acceleration residual have also been employed. Any useful measure of biological age must predict survival better than chronological age does. Meta-analyses indicate that age acceleration difference and age acceleration residual are significant predictors of mortality, qualifying them as indicators of biological age. In this article, we compared the measures based on DNA methylation with FI(34). Using a well-studied cohort, we assessed the efficiency of these measures side by side in predicting mortality. In the presence of chronological age as a covariate, FI(34) was a significant predictor of mortality, whereas none of the DNA methylation age-based metrics were. The outperformance of FI(34) over DNA methylation age measures was apparent when FI(34) and each of the DNA methylation age measures were used together as explanatory variables, along with chronological age: FI(34) remained significant but the DNA methylation measures did not. These results indicate that FI(34) is a robust predictor of biological age, while these DNA methylation measures are largely a statistical reflection of the passage of chronological time

    Muscle Sympathetic Nerve Activity Is Related to a Surrogate Marker of Endothelial Function in Healthy Individuals

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    BACKGROUND: Evidence from animal studies indicates the importance of an interaction between the sympathetic nervous system and the endothelium for cardiovascular regulation. However the interaction between these two systems remains largely unexplored in humans. The aim of this study was to investigate whether directly recorded sympathetic vasoconstrictor outflow is related to a surrogate marker of endothelial function in healthy individuals. METHODS AND RESULTS: In 10 healthy normotensive subjects (3 f/7 m), (age 37+/-11 yrs), (BMI 24+/-3 kg/m(2)) direct recordings of sympathetic action potentials to the muscle vascular bed (MSNA) were performed and endothelial function estimated with the Reactive Hyperaemia- Peripheral Arterial Tonometry (RH-PAT) technique. Blood samples were taken and time spent on leisure-time physical activities was estimated. In all subjects the rate between resting flow and the maximum flow, the Reactive Hyperemic index (RH-PAT index), was within the normal range (1.9-3.3) and MSNA was as expected for age and gender (13-44 burst/minute). RH-PAT index was inversely related to MSNA (r = -0.8, p = 0.005). RH-PAT index and MSNA were reciprocally related to time (h/week) spent on physical activity (p = 0.005 and p = 0.006 respectively) and platelet concentration (PLT) (p = 0.02 and p = 0.004 respectively). CONCLUSIONS: Our results show that sympathetic nerve activity is related to a surrogate marker of endothelial function in healthy normotensive individuals, indicating that sympathetic outflow may be modulated by changes in endothelial function. In this study time spent on physical activity is identified as a predictor of sympathetic nerve activity and endothelial function in a group of healthy individuals. The results are of importance in understanding mechanisms underlying sympathetic activation in conditions associated with endothelial dysfunction and emphasise the importance of a daily exercise routine for maintenance of cardiovascular health

    Childbirth and consequent atopic disease: emerging evidence on epigenetic effects based on the hygiene and EPIIC hypotheses

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    Background: In most high and middle income countries across the world, at least 1:4 women give birth by cesarean section. Rates of labour induction and augmentation are rising steeply; and in some countries up to 50 % of laboring women and newborns are given antibiotics. Governments and international agencies are increasingly concerned about the clinical, economic and psychosocial effects of these interventions. Discussion: There is emerging evidence that certain intrapartum and early neonatal interventions might affect the neonatal immune response in the longer term, and perhaps trans-generationally. Two theories lead the debate in this area. Those aligned with the hygiene (or ‘Old Friends’) hypothesis have examined the effect of gut microbiome colonization secondary to mode of birth and intrapartum/neonatal pharmacological interventions on immune response and epigenetic phenomena. Those working with the EPIIC (Epigenetic Impact of Childbirth) hypothesis are concerned with the effects of eustress and dys-stress on the epigenome, secondary to mode of birth and labour interventions. Summary: This paper examines the current and emerging findings relating to childbirth and atopic/autoimmune disease from the perspective of both theories, and proposes an alliance of research effort. This is likely to accelerate the discovery of important findings arising from both approaches, and to maximize the timely understanding of the longer-term consequences of childbirth practices

    Genome-Wide Analysis of Histone H3 Lysine9 Modifications in Human Mesenchymal Stem Cell Osteogenic Differentiation

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    Mesenchymal stem cells (MSCs) possess self-renewal and multi-lineage differentiation potentials. It has been established that epigenetic mechanisms such as histone modifications could be critical for determining the fate of stem cells. In this study, full human genome promoter microarrays and expression microarrays were used to explore the roles of histone modifications (H3K9Ac and H3K9Me2) upon the induction of MSC osteogenic differentiation. Our results revealed that the enrichment of H3K9Ac was decreased globally at the gene promoters, whereas the number of promoters enriched with H3K9Me2 was increased evidently upon osteogenic induction. By a combined analysis of data from both ChIP-on-chip and expression microarrays, a number of differentially expressed genes regulated by H3K9Ac and/or H3K9Me2 were identified, implicating their roles in several biological events, such as cell cycle withdraw and cytoskeleton reconstruction that were essential to differentiation process. In addition, our results showed that the vitamin D receptor played a trans-repression role via alternations of H3K9Ac and H3K9Me2 upon MSC osteogenic differentiation. Data from this study suggested that gene activation and silencing controlled by changes of H3K9Ac and H3K9Me2, respectively, were crucial to MSC osteogenic differentiation

    Toxic marine microalgae and shellfish poisoning in the British isles: history, review of epidemiology, and future implications

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    The relationship between toxic marine microalgae species and climate change has become a high profile and well discussed topic in recent years, with research focusing on the possible future impacts of changing hydrological conditions on Harmful Algal Bloom (HAB) species around the world. However, there is very little literature concerning the epidemiology of these species on marine organisms and human health. Here, we examine the current state of toxic microalgae species around the UK, in two ways: first we describe the key toxic syndromes and gather together the disparate reported data on their epidemiology from UK records and monitoring procedures. Secondly, using NHS hospital admissions and GP records from Wales, we attempt to quantify the incidence of shellfish poisoning from an independent source. We show that within the UK, outbreaks of shellfish poisoning are rare but occurring on a yearly basis in different regions and affecting a diverse range of molluscan shellfish and other marine organisms. We also show that the abundance of a species does not necessarily correlate to the rate of toxic events. Based on routine hospital records, the numbers of shellfish poisonings in the UK are very low, but the identification of the toxin involved, or even a confirmation of a poisoning event is extremely difficult to diagnose. An effective shellfish monitoring system, which shuts down aquaculture sites when toxins exceed regularity limits, has clearly prevented serious impact to human health, and remains the only viable means of monitoring the potential threat to human health. However, the closure of these sites has an adverse economic impact, and the monitoring system does not include all toxic plankton. The possible geographic spreading of toxic microalgae species is therefore a concern, as warmer waters in the Atlantic could suit several species with southern biogeographical affinities enabling them to occupy the coastal regions of the UK, but which are not yet monitored or considered to be detrimental

    A multidisciplinary approach to identify priority areas for the monitoring of a vulnerable family of fishes in Spanish Marine National Parks

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    Background Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species strongly associated with seaweed and seagrass habitats. Seahorses and pipefishes are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Deficient according to the IUCN (2019), requiring more biological and ecological research. This study provides the first insights into syngnathid populations in the two marine Spanish National Parks (PNIA—Atlantic- and PNAC—Mediterranean). Fishes were collected periodically, marked, morphologically identified, analysed for size, weight, sex and sexual maturity, and sampled for stable isotope and genetic identification. Due the scarcity of previous information, habitat characteristics were also assessed in PNIA. Results Syngnathid diversity and abundance were low, with two species identified in PNIA (Hippocampus guttulatus and Syngnathus acus) and four in PNAC (S. abaster, S. acus, S. typhle and Nerophis maculatus). Syngnathids from both National Parks (NP) differed isotopically, with much lower δ15N in PNAC than in PNIA. The dominant species were S. abaster in PNAC and S. acus in PNIA. Syngnathids preferred less exposed sites in macroalgal assemblages in PNIA and Cymodocea meadows in PNAC. The occurrence of very large specimens, the absence of small-medium sizes and the isotopic comparison with a nearby population suggest that the population of Syngnathus acus (the dominant syngnathid in PNIA) mainly comprised breeders that migrate seasonally. Mitochondrial cytochrome b sequence variants were detected for H. guttulatus, S. acus, and S. abaster, and a novel 16S rDNA haplotype was obtained in N. maculatus. Our data suggest the presence of a cryptic divergent mitochondrial lineage of Syngnathus abaster species in PNAC. Conclusions This is the first multidisciplinary approach to the study of syngnathids in Spanish marine NPs. Habitat preferences and population characteristics in both NPs differed. Further studies are needed to assess the occurrence of a species complex for S. abaster, discarding potential misidentifications of genus Syngnathus in PNAC, and evaluate migratory events in PNIA. We propose several preferential sites in both NPs for future monitoring of syngnathid populations and some recommendations for their conservation.Postprin

    Do hypoxia/normoxia culturing conditions change the neuroregulatory profile of Wharton Jelly mesenchymal stem cells secretome?

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    Introduction: The use of human umbilical cord Wharton Jelly-derived mesenchymal stem cells (hWJ-MSCs) has been considered a new potential source for future safe applications in regenerative medicine. Indeed, the application of hWJ-MSCs into different animal models of disease, including those from the central nervous system, has shown remarkable therapeutic benefits mostly associated with their secretome. Conventionally, hWJ-MSCs are cultured and characterized under normoxic conditions (21 % oxygen tension), although the oxygen levels within tissues are typically much lower (hypoxic) than these standard culture conditions. Therefore, oxygen tension represents an important environmental factor that may affect the performance of mesenchymal stem cells in vivo. However, the impact of hypoxic conditions on distinct mesenchymal stem cell characteristics, such as the secretome, still remains unclear. Methods: In the present study, we have examined the effects of normoxic (21 % O2) and hypoxic (5 % O2) conditions on the hWJ-MSC secretome. Subsequently, we address the impact of the distinct secretome in the neuronal cell survival and differentiation of human neural progenitor cells. Results: The present data indicate that the hWJ-MSC secretome collected from normoxic and hypoxic conditions displayed similar effects in supporting neuronal differentiation of human neural progenitor cells in vitro. However, proteomic analysis revealed that the use of hypoxic preconditioning led to the upregulation of several proteins within the hWJ-MSC secretome. Conclusions: Our results suggest that the optimization of parameters such as hypoxia may lead to the development of strategies that enhance the therapeutic effects of the secretome for future regenerative medicine studies and applications. © 2015 Teixeira et al.Portuguese Foundation for Science and Technology (FCT) (Ciência 2007 program and IF Development Grant (AJS); and pre-doctoral fellowships to FGT (SFRH/69637/ 2010) and SIA (SFRH/BD/81495/2011); Canada Research Chairs (LAB) and a SSE Postdoctoral Fellowship (KMP); The National Mass Spectrometry Network (RNEM) (REDE/1506/REM/2005); co-funded by Programa Operacional Regional do Norte (ON.2 – O Novo Norte), ao abrigo do Quadro de Referência Estratégico Nacional (QREN), através do Fundo Europeu de Desenvolvimento Regional (FEDER).info:eu-repo/semantics/publishedVersio

    Translational studies in the complex role of neurotransmitter systems in anxiety and anxiety disorders

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    Discovery of innovative anxiolytics is severely hampering. Existing anxiolytics are developed decades ago and are still the therapeutics of choice. Moreover, lack of new drug targets forecasts a severe jeopardy in the future treatment of the huge population of CNS-diseased patients. We simply lack the knowledge on what is wrong in brains of anxious people (normal and diseased). Translational research, based on interacting clinical and preclinical research, is extremely urgent. In this endeavor, genetic and genomic approaches are part of the spectrum of contributing factors. We focus on three druggable targets: serotonin transporter, 5-HT1A, and GABAA receptors. It is still uncertain whether and how these targets are involved in normal and diseased anxiety processes. For serotonergic anxiolytics, the slow onset of action points to indirect effects leading to plasticity changes in brain systems leading to reduced anxiety. For GABAA benzodiazepine drugs, acute anxiolytic effects are found indicating primary mechanisms directly influencing anxiety processes. Close translational collaboration between fundamental academic and discovery research will lead to badly needed breakthroughs in the search for new anxiolytics.</p
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