A pathogenic mechanism in Huntington"s disease involves small CAG-repeated RNAs with neurotoxic activity

Huntington's disease (HD) is an autosomal dominantly inherited disorder caused by the expansion of CAG repeats in the Huntingtin (HTT) gene. The abnormally extended polyglutamine in the HTT protein encoded by the CAG repeats has toxic effects. Here, we provide evidence to support that the mutant HTT CAG repeats interfere with cell viability at the RNA level. In human neuronal cells, expanded HTT exon-1 mRNA with CAG repeat lengths above the threshold for complete penetrance (40 or greater) induced cell death and increased levels of small CAG-repeated RNAs (sCAGs), of ≈21 nucleotides in a Dicer-dependent manner. The severity of the toxic effect of HTT mRNA and sCAG generation correlated with CAG expansion length. Small RNAs obtained from cells expressing mutant HTT and from HD human brains significantly decreased neuronal viability, in an Ago2-dependent mechanism. In both cases, the use of anti-miRs specific for sCAGs efficiently blocked the toxic effect, supporting a key role of sCAGs in HTT-mediated toxicity. Luciferase-reporter assays showed that expanded HTT silences the expression of CTG-containing genes that are down-regulated in HD. These results suggest a possible link between HD and sCAG expression with an aberrant activation of the siRNA/miRNA gene silencing machinery, which may trigger a detrimental response. The identification of the specific cellular processes affected by sCAGs may provide insights into the pathogenic mechanisms underlying HD, offering opportunities to develop new therapeutic approaches

Valoració de la capacitat de salt i sincronització temporal intergrupal en la Gimnàstica Estètica de Grup

La Gimnàstica Estètica de Grup (GEG) és un esport emergent del qual no existeix gairebé cap treball de camp i/o publicació. En relació al codi de puntuació d’aquesta modalitat, tant les capacitats de salt com la unitat de moviment del cos i la sincronització entre els membres del conjunt, tenen un pes molt important en la puntuació del valor tècnic i de l’execució. En aquest estudi s’ha realitzat la mesura, avaluació i comparació de les manifestacions de la força explosiva, elàstica i reactiva d’un grup de gimnàstica d’estètica d’alt nivell al principi i al final del període competitiu, mitjançant la bateria de tests de salts verticals de Bosco, concretament SJ, CMJ, CMJas i RJ (15” CMJas). També s’ha analitzat la sincronització i/o coordinació temporal intergrupal d’execució de les dificultats tècniques de salt de les coreografies competitives, al llarg del període competitiu d’un conjunt de gimnàstica estètica d’alt nivell, tenint en compte la sincronització en començar la dificultat i en acabar-la. Els resultats obtinguts demostren que la manifestació de força elàsticoexplosiva en CMJ ha disminuït un 0,46 % i la força explosiva SJ (sense reutilització d'energia elàstica ni aprofitament del reflex miotàtic) ha augmentat un 4,63 %. Durant el període competitiu del conjunt sènior de gimnàstica estètica del Club Muntanyenc Sant Cugat, la influència dels braços en la capacitat de salt ha augmentat un 1,32% i la potència anaeròbica alàctica un 4,76%. Tot i que en la majoria de tests, els resultats han estat positius, no es considera que la mostra hagi assolit una millora significativa, atès que no ha superat el 10% proposat en començar l’estudi, i els valors obtinguts són totalment inestables. S’ha vist que en un mateix test el % de pèrdues i de guanys ha estat molt variat, de manera que no es pot establir una relació de millora de la capacitat de salt en funció de l’entrenament. Pel que fa a la sincronització temporal intergrupal, ha millorat entre un 37,50% (sincronització temps inicial) i un 50,00% (sincronització temps final) en relació a les dificultats tècniques. Fet que és relaciona directament amb l’automatització de mecanismes d’execució al llarg de la temporada competitiva. Tot i així no s’ha igualat o superat la millora d’un 70% proposada per les hipòtesis inicials de l’estudi.

Differences of Functional Connectivity Brain Network in Emotional Judgment

Using combined emotional stimuli, combining photos of faces and recording of voices, we investigated the neural dynamics of emotional judgment using scalp EEG recordings. Stimuli could be either combioned in a congruent, or a non-congruent way.. As many evidences show the major role of alpha in emotional processing, the alpha band was subjected to be analyzed. Analysis was performed by computing the synchronization of the EEGs and the conditions congruent vs. non-congruent were compared using statistical tools. The obtained results demonstrate that scalp EEG ccould be used as a tool to investigate the neural dynamics of emotional valence and discriminate various emotions (angry, happy and neutral stimuli).

Seleção tradicional e associada a marcadores moleculares na avaliação genética animal

O objetivo deste trabalho foi comparar a seleção, utilizando valores genéticos preditos pelo BLUP clássico (BLUP), BLUP marcadores (BLUPM) e pela seleção individual (SI), usando simulação com o programa Genesys. Para obter a matriz de similaridade genética utilizada no BLUPM, foram simulados cem marcadores moleculares do tipo microssatélite (SSR - Simple Sequence Repeat), por meio de um coeficiente de similaridade correspondente à distância euclideana média para dados quantitativos. A fim de comparar os diferentes métodos, utilizaram-se populações com tamanho efetivo de 66,66 e média de 30 repetições, avaliando-se os valores fenotípicos médios. Os ganhos ao longo das 20 gerações de seleção foram maiores para o BLUP em relação ao BLUPM, e este foi superior à SI. Quanto ao ganho obtido nas cinco primeiras gerações, o BLUPM apresentou ganhos semelhantes ao BLUP e superiores à SI. Diferentes sistemas de acasalamento dos reprodutores selecionados não revelaram diferenças em ganho genético nos métodos baseados no BLUP.

Telomere fluorescence measurements in granulocytes and T lymphocyte subsets point to a high turnover of hematopoietic stem cells and memory T cells in early childhood.

To study telomere length dynamics in hematopoietic cells with age, we analyzed the average length of telomere repeat sequences in diverse populations of nucleated blood cells. More than 500 individuals ranging in age from 0 to 90 yr, including 36 pairs of monozygous and dizygotic twins, were analyzed using quantitative fluorescence in situ hybridization and flow cytometry. Granulocytes and naive T cells showed a parallel biphasic decline in telomere length with age that most likely reflected accumulated cell divisions in the common precursors of both cell types: hematopoietic stem cells. Telomere loss was very rapid in the first year, and continued for more than eight decades at a 30-fold lower rate. Memory T cells also showed an initial rapid decline in telomere length with age. However, in contrast to naive T cells, this decline continued for several years, and in older individuals lymphocytes typically had shorter telomeres than did granulocytes. Our findings point to a dramatic decline in stem cell turnover in early childhood and support the notion that cell divisions in hematopoietic stem cells and T cells result in loss of telomeric DNA.

Leishmania major: histone H1 gene expression from the sw3 locus.

Histone H1 in the parasitic protozoan Leishmania is a developmentally regulated protein encoded by the sw3 gene. Here we report that histone H1 variants exist in different Leishmania species and strains of L. major and that they are encoded by polymorphic genes. Amplification of the sw3 gene from the genome of three strains of L. major gave rise to different products in each strain, suggesting the presence of a multicopy gene family. In L. major, these genes were all restricted to a 50-kb Bg/II fragment found on a chromosomal band of 1.3 Mb (chromosome 27). The detection of RFLPs in this locus demonstrated its heterogeneity within several species and strains of Leishmania. Two different copies of sw3 (sw3.0 and sw3.1) were identified after screening a cosmid library containing L. major strain Friedlin genomic DNA. They were identical in their 5' UTRs and open reading frames, but differed in their 3' UTRs. With respect to the originally cloned copy of sw3 from L. major strain LV39, their open reading frames lacked a repeat unit of 9 amino acids. Immunoblots of L. guyanensis parasites transfected with these cosmids revealed that both copies could give rise to the histone H1 protein. The characterization of this locus will now make possible a detailed analysis of the function of histone H1 in Leishmania, as well as permit the dissection of the molecular mechanisms governing the developmental regulation of the sw3 gene.

The 3' half of the mouse mammary tumor virus orf gene is not sufficient for its superantigen function in transgenic mice.

The Mouse Mammary Tumor Virus (MMTV) long terminal repeat contains an open reading frame (orf) of 960 nucleotides encoding a 36 kDa polypeptide with a putative transmembrane domain and five N-glycosylation sites in the N-terminal part of the protein. Transgenic mice bearing either the complete or the 3' terminal half of the orf sequence of MMTV-GR under the control of the SV40 promoter were raised. As shown previously by FACS analysis transgenic mice which express the complete orf gene have a significant deletion of V beta 14 expressing T cells at 6 weeks of age. Here we show that no clonal deletion of V beta 14 bearing T cells takes place in transgenic mice that contain orf sequences from the fifth ATG to the termination codon. The pattern of tissues expressing the truncated transgene was studied by the Polymerase Chain Reaction (PCR) and was very similar to the one obtained in the V beta 14 deleting animals. These data suggest that the amino-terminal portion of the ORF protein (pORF) is required for a superantigen function, while our previous data indicated that determinants from the carboxy-terminus play an important role for TCR V beta specificity.

Caspase-1 autoproteolysis is differentially required for NLRP1b and NLRP3 inflammasome function.

Inflammasomes are caspase-1-activating multiprotein complexes. The mouse nucleotide-binding domain and leucine rich repeat pyrin containing 1b (NLRP1b) inflammasome was identified as the sensor of Bacillus anthracis lethal toxin (LT) in mouse macrophages from sensitive strains such as BALB/c. Upon exposure to LT, the NLRP1b inflammasome activates caspase-1 to produce mature IL-1β and induce pyroptosis. Both processes are believed to depend on autoproteolysed caspase-1. In contrast to human NLRP1, mouse NLRP1b lacks an N-terminal pyrin domain (PYD), indicating that the assembly of the NLRP1b inflammasome does not require the adaptor apoptosis-associated speck-like protein containing a CARD (ASC). LT-induced NLRP1b inflammasome activation was shown to be impaired upon inhibition of potassium efflux, which is known to play a major role in NLRP3 inflammasome formation and ASC dimerization. We investigated whether NLRP3 and/or ASC were required for caspase-1 activation upon LT stimulation in the BALB/c background. The NLRP1b inflammasome activation was assessed in both macrophages and dendritic cells lacking either ASC or NLRP3. Upon LT treatment, the absence of NLRP3 did not alter the NLRP1b inflammasome activity. Surprisingly, the absence of ASC resulted in IL-1β cleavage and pyroptosis, despite the absence of caspase-1 autoprocessing activity. By reconstituting caspase-1/caspase-11(-/-) cells with a noncleavable or catalytically inactive mutant version of caspase-1, we directly demonstrated that noncleavable caspase-1 is fully active in response to the NLRP1b activator LT, whereas it is nonfunctional in response to the NLRP3 activator nigericin. Taken together, these results establish variable requirements for caspase-1 cleavage depending on the pathogen and the responding NLR.

Surgical outcomes of deep sclerectomy versus Baerveldt aqueous shunt implantation following initial failed deep sclerectomy

Purpose: To examine the efficacy and safety of repeat deep sclerectomy (DS) versus Baerveldt shunt (BS) implantation as second line surgery following failed primary DS. Methods: Fifty one patients were prospectively recruited to undergo BS implantation following failed DS and 51 patients underwent repeat DS, for which data was collected retrospectively. All eyes had at least one failed DS. Surgical success was defined as IOP≤21mmHg and 20% reduction in IOP from baseline. Success rates, number of glaucoma medications (GMs), IOP, and complication rates were compared between the two groups at year 1, post-operatively. Results: Mean age, sex and the proportion of glaucoma subtypes were similar between groups. Preoperatively IOP was significantly lower in DS group vs BS group (18.8mmHg vs 23.8mmHg, p<0.01, two sample t-test). Postoperatively IOP was significantly higher in DS group than BS group (14.6mmHg vs 12.0mmHg, p<0.01, two-sample t-test). In the DS group, 47% of eyes did not achieve 20% reduction in IOP from baseline, as a result the success rates were significantly lower in eyes with DS (51%) than in eyes with BS (88%) (p=0.02, log-rank test). Preoperatively the number of GMs used in DS and BS groups were similar (2.2 vs 2.7 p=0.02, two sample t-test). Postoperatively there remained no significant difference in GMs between groups (0.9 vs 1.1, p= 0.58, two sample t-test). Complication rates were similar between the two groups (12% vs 10%). Conclusions: Baerveldt tube implantation was more effective in lowering IOP than repeat deep sclerectomy in eyes with failed primary DS, at year one. Complications were minor and infrequent in both groups

Metastatic leishmaniasis. A chronic inflammatory response to Leishmania's viral endosymbiont.

Leishmania parasites have been plaguing humankind for centuries as a range of skin diseases named the cutaneous leishmaniases (CL). Carried in a hematophagous sand fly, Leishmania usually infests the skin surrounding the bite site, causing a destructive immune response that may persist for months or even years. The various symptomatic outcomes of CL range from a benevolent self- healing reddened bump to extensive open ulcerations, resistant to treatment and resulting in life- changing disfiguration. Many of these more aggressive outcomes are geographically isolated within the habitats of certain Neotropical Leishmania species; where about 15% of cases experience metastatic complications. However, despite this correlation, genetic analysis has revealed no major differences between species causing the various disease forms. We have recently identified a cytoplasmic dsRNA virus within metastatic L. guyanensis parasites that acts as a potent innate immunogen capable of worsening lesionai inflammation and prolonging parasite survival. The dsRNA genome of Leishmania RNA virus (LRV) binds and stimulates Toll-Like-Receptor-3 (TLR3), inducing this destructive inflammation, which we speculate as a factor contributing to the development of metastatic disease. This thesis establishes the first experimental model of LRV-mediated leishmanial metastasis and investigates the role of non-TLR3 viral recognition pathways in LRV-mediated pathology. Viral dsRNA can be detected by various non-TLR3 pattern recognition receptors (PRR); two such PRR groups are the RLRs (Retinoic acid-inducible gene 1 like receptors) and the NLRs (nucleotide- binding domain, leucine-rich repeat containing receptors). The RLRs are designed to detect viral dsRNA in the cytoplasm, while the NLRs react to molecular "danger" signals of cell damage, often oligomerizing into molecular scaffolds called "inflammasomes" that activate a potent inflammatory cascade. Interestingly, we found that neither RLR signalling nor the inflammasome pathway had an effect on LRV-mediated pathology. In contrast, we found a dramatic inflammasome independent effect for the NLR family member, NLRP10, where a knockout mouse model showed little evidence of disease. This phenotype was mimicked in an NLR knockout with which NLRP10 is known to interact: NLRC2. As this pathway induces the chronic inflammatory cell lineage TH17, we investigated the role of its key chronic inflammatory cytokine, IL-17A, in human patients infected by L. guyanensis. Indeed, patients infected with LRV+ parasites had a significantly increased level of IL-17A in lesionai biopsies. Interestingly, LRV presence was also associated with a significant decrease in the correlate of protection, IFN-y. This association was repeated in our murine model, where after we were able to establish the first experimental model of LRV-dependent leishmanial metastasis, which was mediated by IL-17A in the absence of IFN-y. Finally, we tested a new inhibitor of IL-17A secretion, SR1001, and reveal its potential as a Prophylactic immunomodulator and potent parasitotoxic drug. Taken together, these findings provide a basis for anti-IL-17A as a feasible therapeutic intervention to prevent and treat the metastatic complications of cutaneous leishmaniasis. -- Les parasites Leishmania infectent l'homme depuis des siècles causant des affections cutanées, appelées leishmanioses cutanées (LC). Le parasite est transmis par la mouche des sables et réside dans le derme à l'endroit de la piqûre. Au niveau de la peau, le parasite provoque une réponse immunitaire destructrice qui peut persister pendant des mois voire des années. Les symptômes de LC vont d'une simple enflure qui guérit spontanément jusqu' à de vastes ulcérations ouvertes, résistantes aux traitements. Des manifestations plus agressives sont déterminées par les habitats géographiques de certaines espèces de Leishmania. Dans ces cas, environ 15% des patients développent des lésions métastatiques. Aucun «facteur métastatique» n'a encore été trouvé à ce jour dans ces espèces. Récemment, nous avons pu identifier un virus résidant dans certains parasites métastatiques présents en Guyane française (appelé Leishmania-virus, ou LV) et qui confère un avantage de survie à son hôte parasitaire. Ce virus active fortement la réponse inflammatoire, aggravant l'inflammation et prolongeant l'infection parasitaire. Afin de diagnostiquer, prévenir et traiter ces lésions, nous nous sommes intéressés à identifier les composants de la voie de signalisation anti-virale, responsables de la persistance de cette inflammation. Cette étude décrit le premier modèle expérimental de métastases de la leishmaniose induites par LV, et identifie plusieurs composants de la voie inflammatoire anti-virale qui facilite la pathologie métastatique. Contrairement à l'homme, les souris de laboratoire infectées par des Leishmania métastatiques (contenant LV, LV+) ne développent pas de lésions métastatiques et guérissent après quelques semaines d'infection. Après avoir analysé un groupe de patients atteints de leishmaniose en Guyane française, nous avons constaté que les personnes infectées avec les parasites métastatiques LV+ avaient des niveaux significativement plus faibles d'un composant immunitaire protecteur important, appelé l'interféron (IFN)-y. En utilisant des souris génétiquement modifiées, incapables de produire de l'IFN-y, nous avons observé de telles métastases. Après inoculation dans le coussinet plantaire de souris IFN-y7" avec des parasites LV+ ou LV-, nous avons démontré que seules les souris infectées avec des leishmanies ayant LV développent de multiples lésions secondaires sur la queue. Comme nous l'avons observé chez l'homme, ces souris sécrètent une quantité significativement élevée d'un composant inflammatoire destructeur, l'interleukine (IL)-17. IL-17 a été incriminée pour son rôle dans de nombreuses maladies inflammatoires chroniques. On a ainsi trouvé un rôle destructif similaire pour l'IL-17 dans la leishmaniose métastatique. Nous avons confirmé ce rôle en abrogeant IL-17 dans des souris IFN-y7- ce qui ralentit l'apparition des métastases. Nous pouvons donc conclure que les métastases de la leishmaniose sont induites par l'IL-17 en absence d'IFN-v. En analysant plus en détails les voies de signalisation anti-virale induites par LV, nous avons pu exclure d'autres voies d'activation de la réponse inflammatoire. Nous avons ainsi démontré que la signalisation par LV est indépendante de la signalisation inflammatoire de type « inflammasome ». En revanche, nous avons pu y lier plusieurs autres molécules, telles que NLRP10 et NLRC2, connues pour leur synergie avec les réponses inflammatoires. Cette nouvelle voie pourrait être la cible pour des médicaments inhibant l'inflammation. En effet, un nouveau médicament qui bloque la production d'IL-17 chez la souris s'est montré prometteur dans notre modèle : il a réduit le gonflement des lésions ainsi que la charge parasitaire, indiquant que la voie anti-virale /inflammatoire est une approche thérapeutique possible pour prévenir et traiter cette infection négligée.

Elevation gradient of successful plant traits for colonizing alpine summits under climate change

Upward migration of plant species due to climate change has become evident in several European mountain ranges. It is still, however, unclear whether certain plant traits increase the probability that a species will colonize mountain summits or vanish, and whether these traits differ with elevation. Here, we used data from a repeat survey of the occurrence of plant species on 120 summits, ranging from 2449 to 3418 m asl, in south-eastern Switzerland to identify plant traits that increase the probability of colonization or extinction in the 20th century. Species numbers increased across all plant traits considered. With some traits, however, numbers increased proportionally more. The most successful colonizers seemed to prefer warmer temperatures and well-developed soils. They produced achene fruits and/or seeds with pappus appendages. Conversely, cushion plants and species with capsule fruits were less efficient as colonizers. Observed changes in traits along the elevation gradient mainly corresponded to the natural distribution of traits. Extinctions did not seem to be clearly related to any trait. Our study showed that plant traits varied along both temporal and elevational gradients. While seeds with pappus seemed to be advantageous for colonization, most of the trait changes also mirrored previous gradients of traits along elevation and hence illustrated the general upward migration of plant species. An understanding of the trait characteristics of colonizing species is crucial for predicting future changes in mountain vegetation under climate change.

Automatic quality assessment in structural brain magnetic resonance imaging

MRI has evolved into an important diagnostic technique in medical imaging. However, reliability of the derived diagnosis can be degraded by artifacts, which challenge both radiologists and automatic computer-aided diagnosis. This work proposes a fully-automatic method for measuring image quality of three-dimensional (3D) structural MRI. Quality measures are derived by analyzing the air background of magnitude images and are capable of detecting image degradation from several sources, including bulk motion, residual magnetization from incomplete spoiling, blurring, and ghosting. The method has been validated on 749 3D T(1)-weighted 1.5T and 3T head scans acquired at 36 Alzheimer's Disease Neuroimaging Initiative (ADNI) study sites operating with various software and hardware combinations. Results are compared against qualitative grades assigned by the ADNI quality control center (taken as the reference standard). The derived quality indices are independent of the MRI system used and agree with the reference standard quality ratings with high sensitivity and specificity (>85%). The proposed procedures for quality assessment could be of great value for both research and routine clinical imaging. It could greatly improve workflow through its ability to rule out the need for a repeat scan while the patient is still in the magnet bore.

Molecular interactions involved in the transactivation of the human T-cell leukemia virus type 1 promoter mediated by Tax and CREB-2 (ATF-4).

The human T-cell leukemia virus type 1 (HTLV-1) Tax protein activates viral transcription through three 21-bp repeats located in the U3 region of the HTLV-1 long terminal repeat and called Tax-responsive elements (TxREs). Each TxRE contains nucleotide sequences corresponding to imperfect cyclic AMP response elements (CRE). In this study, we demonstrate that the bZIP transcriptional factor CREB-2 is able to bind in vitro to the TxREs and that CREB-2 binding to each of the 21-bp motifs is enhanced by Tax. We also demonstrate that Tax can weakly interact with CREB-2 bound to a cellular palindromic CRE motif such as that found in the somatostatin promoter. Mutagenesis of Tax and CREB-2 demonstrates that both N- and C-terminal domains of Tax and the C-terminal region of CREB-2 are required for direct interaction between the two proteins. In addition, the Tax mutant M47, defective for HTLV-1 activation, is unable to form in vitro a ternary complex with CREB-2 and TxRE. In agreement with recent results suggesting that Tax can recruit the coactivator CREB-binding protein (CBP) on the HTLV-1 promoter, we provide evidence that Tax, CREB-2, and CBP are capable of cooperating to stimulate viral transcription. Taken together, our data highlight the major role played by CREB-2 in Tax-mediated transactivation.

Genetic variability of Brazilian rice landraces determined by SSR markers

The objective of this study was to evaluate the genetic variability of rice (Oryza sativa) landraces collected in Brazilian small farms. Twelve simple sequence repeat (SSR) markers characterized 417 landraces collected in 1986, 1987 and 2003, in the state of Goiás, Brazil. The number of landraces with long and thin grain type increased in the evaluated period, probably due to market demand. Based on the molecular data, the genetic variability increased during this period and, as per to the factorial correspondence analysis, most of the accessions were grouped according to the year of collection. The incorporation of modern rice cultivars in landrace cultivation areas and the selection carried out by small farmers are the most probable factors responsible for increasing landrace genetic variability, during the evaluated period. Genotype exchange between farmers, selection practice and local environmental adaptation are able to generate novel adapted allele combinations, which can be used by breeding programs, to reinitiate the process.

Genetic diversity in soybean germplasm identified by SSR and EST-SSR markers

The objectives of this work were to investigate the genetic variation in 79 soybean (Glycine max) accessions from different regions of the world, to cluster the accessions based on their similarity, and to test the correlation between the two types of markers used. Simple sequence repeat markers present in genomic (SSR) and in expressed regions (EST-SSR) were used. Thirty SSR primer-pairs were selected (20 genomic and 10 EST-SSR) based on their distribution on the 20 genetic linkage groups of soybean, on their trinucleotide repetition unit and on their polymorphism information content. All analyzed loci were polymorphic, and 259 alleles were found. The number of alleles per locus varied from 2-21, with an average of 8.63. The accessions exhibit a significant number of rare alleles, with genotypes 19, 35, 63 and 65 carrying the greater number of exclusive alleles. Accessions 75 and 79 were the most similar and accessions 31 and 35, and 40 and 78, were the most divergent ones. A low correlation between SSR and EST-SSR data was observed, thus genomic and expressed microsatellite markers are required for an appropriate analysis of genetic diversity in soybean. The genetic diversity observed was high and allowed the formation of five groups and several subgroups. A moderate relationship between genetic divergence and geographic origin of accessions was observed.