450 research outputs found
Expression of the Parkinsonâs Disease-Associated Gene Alpha-Synuclein is Regulated by the Neuronal Cell Fate Determinant TRIM32
Alpha-synuclein is an abundant neuronal protein which has been associated with physiological processes like synaptic function, neurogenesis, and neuronal differentiation but also with pathological neurodegeneration. Indeed, alpha-synuclein (snca) is one of the major genes implicated in Parkinsonâs disease (PD). However, little is known about the regulation of alpha-synuclein expression. Unveiling the mechanisms that control its regulation is of high importance, as it will enable to further investigate and comprehend the physiological role of alpha-synuclein as well as its potential contribution in the aetiology of PD. Previously, we have shown that the protein TRIM32 regulates fate specification of neural stem cells. Here, we investigated the impact of TRIM32 on snca expression regulation in vitro and in vivo in neural stem cells and neurons. We demonstrated that TRIM32 is positively influencing snca expression in a neuronal cell line, while the absence of TRIM32 is causing deregulated levels of snca transcripts. Finally, we provided evidence that TRIM32 binds to the promoter region of snca, suggesting a novel mechanism of its transcriptional regulation. On the one hand, the presented data link the PD-associated gene alpha-synuclein to the neuronal cell fate determinant TRIM32 and thereby support the concept that PD is a neurodevelopmental disorder. On the other hand, they imply that defects in olfactory bulb adult neurogenesis might contribute to early PD-associated non-motor symptoms like hyposmia.The J. C. S.âs lab is supported by the Boehringer Ingelheim Foundation and the fund âInnovative Medical Researchâ of the University of MĂŒnster Medical School, Schram-Stiftung (T287/21795/2011) by the Fonds National de la Recherche (FNR) Luxembourg (CORE, C13/BM/5791363), a University Luxembourg Internal Research Project (MidNSCs) and the EU Joint Programme - Neurodegenerative Disease Research (JPND) project (supported by the FNR). L.G.C. was supported by a fellowship from the FNR (AFR, Aides Ă la Formation-Recherche). M.C.M âs lab is supported by Grant SAF2012-36143 from Spanish Ministerio de Ciencia e and LE310U14 from the Junta de Castilla y Leon. S.F.A holds a predoctoral contract (PIRTU) from Junta de Castilla y Leon
Assessment of table olives' organoleptic defect intensities based on the potentiometric fingerprint recorded by an electronic tongue
Table olives are prone to the appearance of sensory defects that decrease their quality and in some cases result in olives unsuitable for consumption. The evaluation of the type and intensity of the sensory negative attributes of table olives is recommended by the International Olive Council, although not being legally required for commercialization. However, the accomplishment of this task requires the training and implementation of sensory panels according to strict directives, turning out in a time-consuming and expensive procedure that involves a degree of subjectivity. In this work, an electronic tongue is proposed as a taste sensor device for evaluating the intensity of sensory defects of table olives. The potentiometric signal profiles gathered allowed establishing multiple linear regression models, based on the most informative subsets of signals (from 24 to 29 recorded during the analysis of olive aqueous pastes and brine solutions) selected using a simulated annealing meta-heuristic algorithm. The models enabled the prediction of the median intensities (R2 â„ 0.942 and RMSE †0.356, for leave-one-out or repeated K-fold cross-validation procedures) of butyric, musty, putrid, winey-vinegary, and zapateria negative sensations being, in general, the predicted intensities within the range of intensities perceived by the sensory panel. Indeed, based on the predicted mean intensities of the sensory defects, the electrochemical-chemometric approach developed could correctly classify 86.4% of the table olive samples according to their trade category based on a sensory panel evaluation and following the International Olive Council regulations (i.e., extra, 1st choice, 2nd choice, and olives that may not be sold as table olives). So, the satisfactory overall predictions achieved demonstrate that the electronic tongue could be a complementary tool for assessing table olive defects, reducing the effort of trained panelists and minimizing the risk of subjective evaluations.This work was financially supported by Project POCI-01-0145-FEDER-006984âAssociate Laboratory LSRE-LCM, by Project UID/QUI/00616/2013 âCQ-VR, and UID/AGR/00690/ 2013âCIMO, all funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through COMPETE2020âPrograma Operacional Competitividade e Internacionalização (POCI) and by national funds through Fundação para a CiĂȘncia e a Tecnologia (FCT), Portugal. Strategic funding of UID/BIO/04469/2013 unit is also acknowledged. Nuno Rodrigues thanks FCT, POPH-QREN, and FSE for the Ph.D. Grant (SFRH/BD/104038/2014).info:eu-repo/semantics/publishedVersio
CaracterizaciĂłn del HLA en una familia colombiana endogĂĄmica con sĂndrome de Usher
Resumen
El sĂndrome de Usher es una enfermedad autosĂłmica recesiva que se caracteriza por presentar retinitis pigmentosa, hipoacusia neurosensorial congĂ©nita y disfunciĂłn vestibular. El propĂłsito de este trabajo es realizar la caracterizaciĂłn de hla en una familia colombiana endogĂĄmica que presenta sĂndrome de Usher. La metodologĂa consiste en que con un previo consentimiento informado se realizĂł una genealogĂa de la familia y a cuatro pacientes confirmados clĂnicamente con sĂndrome de Usher y a cuatro fenotĂpicamente sanos se les tomĂł 5 ml de sangre perifĂ©rica en tubos de venopunciĂłn con edta para luego realizar el aislamiento del dna por la tĂ©cnica de salting out, conservados en buffer te a -8 °C y ajustada la muestra a una concentraciĂłn de 8 ÎŒg/ml. Posteriormente a travĂ©s de la tĂ©cnica de pcr-ssp de mediana resoluciĂłn se caracterizaron los antĂgenos de hla *a, *b, *drb1 y *dqb1. Los resultados obtenidos indican que la familia oriunda del Departamento del Huila presenta una marcada endogamia detectĂĄndose que todos los hermanos afectados, sus padres son hermanos tambiĂ©n y una de las parejas a su vez tuvo una niña afectada, por lo que sus abuelos y padres son hermanos. En lo referente al hla, los alelos mĂĄs frecuentemente encontrados fueron a30 b42 dr1 dq5 y a3 b45 dr12 y dq7, que no estĂĄn asociados a la enfermedad. Estos resultados sugieren que dada la endogamia que muestra esta familia se presenta una gran acumulaciĂłn de polimorfismos y mutaciones, por lo que es necesario realizar un proceso de asesorĂa genĂ©tica para disminuir el riesgo de recurrencia.
Abstract
Usher syndrome is an autosomal recessive disease characterized by retinitis pigmentosa, congenital sensorineural hearing loss and vestibular dysfunction. The purpose of this work was to characterize hla in an inbred Colombian family that presents Usher Syndrome. The Methodology consisted in that a genealogy of the family was made and previous informed consent, from four patients clinically confirmed with Usher Syndrome and four phenotypically healthy patients 5 ml of peripheral blood were taken in venipuncture tubes with edta and then the dna isolation was performed with the technique of salting out, preserved in te buffer at -8 °C and adjusted the sample to a concentration of 8 Όg/ml. The hla *A, *B, *DRB1 and *DQB1 antigens were then characterized by the medium-resolution pcr-ssp techniqu
CaracterizaciĂłn del HLA en una familia colombiana endogĂĄmica con sĂndrome de Usher
El sĂndrome de Usher es una enfermedad autosĂłmica recesiva que se caracteriza por presentar retinitis pigmentosa, hipoacusia neurosensorial congĂ©nita y disfunciĂłn vestibular. El propĂłsito de este trabajo es realizar la caracterizaciĂłn de hla en una familia colombiana endogĂĄmica que presenta sĂndrome de Usher. La metodologĂa consiste en que con un previo consentimiento informado se realizĂł una genealogĂa de la familia y a cuatro pacientes confirmados clĂnicamente con sĂndrome de Usher y a cuatro fenotĂpicamente sanos se les tomĂł 5 ml de sangre perifĂ©rica en tubos de venopunciĂłn con edta para luego realizar el aislamiento del dna por la tĂ©cnica de salting out, conservados en buffer te a -8 °C y ajustada la muestra a una concentraciĂłn de 8 ÎŒg/ml. Posteriormente a travĂ©s de la tĂ©cnica de pcr-ssp de mediana resoluciĂłn se caracterizaron los antĂgenos de hla *a, *b, *drb1 y *dqb1. Los resultados obtenidos indican que la familia oriunda del Departamento del Huila presenta una marcada endogamia detectĂĄndose que todos los hermanos afectados, sus padres son hermanos tambiĂ©n y una de las parejas a su vez tuvo una niña afectada, por lo que sus abuelos y padres son hermanos. En lo referente al hla, los alelos mĂĄs frecuentemente encontrados fueron a30 b42 dr1 dq5 y a3 b45 dr12 y dq7, que no estĂĄn asociados a la enfermedad. Estos resultados sugieren que dada la endogamia que muestra esta familia se presenta una gran acumulaciĂłn de polimorfismos y mutaciones, por lo que es necesario realizar un proceso de asesorĂa genĂ©tica para disminuir el riesgo de recurrencia
Histoplasma capsulatum proteome response to decreased iron availability
<p>Abstract</p> <p>Background</p> <p>A fundamental pathogenic feature of the fungus <it>Histoplasma capsulatum </it>is its ability to evade innate and adaptive immune defenses. Once ingested by macrophages the organism is faced with several hostile environmental conditions including iron limitation. <it>H. capsulatum </it>can establish a persistent state within the macrophage. A gap in knowledge exists because the identities and number of proteins regulated by the organism under host conditions has yet to be defined. Lack of such knowledge is an important problem because until these proteins are identified it is unlikely that they can be targeted as new and innovative treatment for histoplasmosis.</p> <p>Results</p> <p>To investigate the proteomic response by <it>H. capsulatum </it>to decreasing iron availability we have created <it>H. capsulatum </it>protein/genomic databases compatible with current mass spectrometric (MS) search engines. Databases were assembled from the <it>H. capsulatum </it>G217B strain genome using gene prediction programs and expressed sequence tag (EST) libraries. Searching these databases with MS data generated from two dimensional (2D) in-gel digestions of proteins resulted in over 50% more proteins identified compared to searching the publicly available fungal databases alone. Using 2D gel electrophoresis combined with statistical analysis we discovered 42 <it>H. capsulatum </it>proteins whose abundance was significantly modulated when iron concentrations were lowered. Altered proteins were identified by mass spectrometry and database searching to be involved in glycolysis, the tricarboxylic acid cycle, lysine metabolism, protein synthesis, and one protein sequence whose function was unknown.</p> <p>Conclusion</p> <p>We have created a bioinformatics platform for <it>H. capsulatum </it>and demonstrated the utility of a proteomic approach by identifying a shift in metabolism the organism utilizes to cope with the hostile conditions provided by the host. We have shown that enzyme transcripts regulated by other fungal pathogens in response to lowering iron availability are also regulated in <it>H. capsulatum </it>at the protein level. We also identified <it>H. capsulatum </it>proteins sensitive to iron level reductions which have yet to be connected to iron availability in other pathogens. These data also indicate the complexity of the response by <it>H. capsulatum </it>to nutritional deprivation. Finally, we demonstrate the importance of a strain specific gene/protein database for <it>H. capsulatum </it>proteomic analysis.</p
Epithelial-Mesenchymal Transition in Cells Expanded In Vitro from Lineage-Traced Adult Human Pancreatic Beta Cells
BACKGROUND: In-vitro expansion of functional beta cells from adult human islets is an attractive approach for generating an abundant source of cells for beta-cell replacement therapy of diabetes. Using genetic cell-lineage tracing we have recently shown that beta cells cultured from adult human islets undergo rapid dedifferentiation and proliferate for up to 16 population doublings. These cells have raised interest as potential candidates for redifferentiation into functional insulin-producing cells. Previous work has associated dedifferentiation of cultured epithelial cells with epithelial-mesenchymal transition (EMT), and suggested that EMT generates cells with stem cell properties. Here we investigated the occurrence of EMT in these cultures and assessed their stem cell potential. METHODOLOGY/PRINCIPAL FINDINGS: Using cell-lineage tracing we provide direct evidence for occurrence of EMT in cells originating from beta cells in cultures of adult human islet cells. These cells express multiple mesenchymal markers, as well as markers associated with mesenchymal stem cells (MSC). However, we do not find evidence for the ability of such cells, nor of cells in these cultures derived from a non-beta-cell origin, to significantly differentiate into mesodermal cell types. CONCLUSIONS/SIGNIFICANCE: These findings constitute the first demonstration based on genetic lineage-tracing of EMT in cultured adult primary human cells, and show that EMT does not induce multipotency in cells derived from human beta cells
Genome of the Avirulent Human-Infective TrypanosomeâTrypanosoma rangeli
Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts. Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins. Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets
Corrosion Performance of Friction Stir Linear Lap Welded AM60B Joints
A corrosion investigation of friction stir linear lap welded AM60B joints used to fabricate an Mg alloy-intensive automotive front end sub-assembly was performed. The stir zone exhibited a slightly refined grain size and significant break-up and re-distribution of the divorced Mg17Al12 (ÎČ-phase) relative to the base material. Exposures in NaCl (aq) environments revealed that the stir zone was more susceptible to localized corrosion than the base material. Scanning vibrating electrode technique measurements revealed differential galvanic activity across the joint. Anodic activity was confined to the stir zone surface and involved initiation and lateral propagation of localized filaments. Cathodic activity was initially confined to the base material surface, but was rapidly modified to include the cathodically-activated corrosion products in the filament wake. Site-specific surface analyses revealed that the corrosion observed across the welded joint was likely linked to variations in Al distribution across the surface film/metal interface
Are âEnduranceâ Alleles âSurvivalâ Alleles? Insights from the ACTN3 R577X Polymorphism
Exercise phenotypes have played a key role for ensuring survival over human evolution. We speculated that some genetic variants that influence exercise phenotypes could be associated with exceptional survival (i.e. reaching â„100years of age). Owing to its effects on muscle structure/function, a potential candidate is the Arg(R)577Ter(X) polymorphism (rs1815739) in ACTN3, the structural gene encoding the skeletal muscle protein α-actinin-3. We compared the ACTN3 R577X genotype/allele frequencies between the following groups of ethnically-matched (Spanish) individuals: centenarians (cases, nâ=â64; 57 female; age range: 100â108 years), young healthy controls (nâ=â283, 67 females, 216 males; 21±2 years), and humans who are at the two end-points of exercise capacity phenotypes, i.e. muscle endurance (50 male professional road cyclists) and muscle power (63 male jumpers/sprinters). Although there were no differences in genotype/allele frequencies between centenarians (RR:28.8%; RX:47.5%; XX:23.7%), and controls (RR:31.8%; RX:49.8%; XX:18.4%) or endurance athletes (RR:28.0%; RX:46%; XX:26.0%), we observed a significantly higher frequency of the X allele (Pâ=â0.019) and XX genotype (Pâ=â0.011) in centenarians compared with power athletes (RR:47.6%; RX:36.5%;XX:15.9%). Notably, the frequency of the null XX (α-actinin-3 deficient) genotype in centenarians was the highest ever reported in non-athletic Caucasian populations. In conclusion, despite there were no significant differences with the younger, control population, overall the ACTN3 genotype of centenarians resembles that of world-class elite endurance athletes and differs from that of elite power athletes. Our preliminary data would suggest a certain âsurvivalâ advantage brought about by α-actinin-3 deficiency and the âenduranceâ/oxidative muscle phenotype that is commonly associated with this condition
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