Regulation of patterned dynamics of local exocytosis in growth cones by netrin-1

Axonal guidance and synaptic specification depends on specific signaling mechanisms that occur in growth cones. While several signaling pathways implicated in cone navigation have been identified, membrane dynamics in growth cones remains largely unknown. We took advantage of SynaptopHluorin and high-speed optical recordings to monitor the patterns of membrane dynamics in rat hippocampal growth cones. We show that exocytosis occurs both at the peripheral and central domains, including filopodia, and that SynaptopHluorin signals occur as spontaneous patterned peaks. Such transients average approximately two per minute and last ∼30 s. We also demonstrate that the chemoattractant Netrin-1 elicits increases in the frequency and slopes of these transients, with peaks averaging up to six per minute in the peripheral domain. Netrin-1-dependent regulation of exocytotic events requires the activation of the Erk1/2 and SFK pathways. Furthermore, we show that domains with high SynaptopHluorin signals correlate with high local calcium concentrations and that local, spontaneous calcium increases are associated with higher SynaptopHluorin signals. These findings demonstrate highly stereotyped, spontaneous transients of local exocytosis in growth cones and that these transients are positively regulated by chemoattractant molecules such as Netrin-1

Detection of homozygous genotypes for a putatively lethal recessive mutation in the porcine argininosuccinate synthase 1 (ASS1) gene

The sequencing of the pig genome revealed the existence of homozygous individuals for a nonsense mutation in the argininosuccinate synthase 1 (ASS1) gene (rs81212146, c.944T>A, L315X). Paradoxically, an AA homozygous genotype for this polymorphism is expected to abolish the function of the ASS1 enzyme that participates in the urea cycle, leading to citrullinemia, hyperammonemia, coma and death. Sequencing of five Duroc boars that sired a population of 350 Duroc barrows revealed the segregation of the c.944T>A polymorphism, so we aimed to investigate its phenotypic consequences. Genotyping of this mutation in the 350 Duroc barrows revealed the existence of seven individuals homozygous (AA) for the nonsense mutation. These AA pigs had a normal weight despite the fact that mild citrullinemia often involves impaired growth. Sequencing of the region surrounding the mutation in TT, TA and AA individuals revealed that the A substitution in the second position of the codon (c.944T>A) is in complete linkage disequilibrium with a C replacement (c.943T>C) in the first position of the codon. This second mutation would compensate for the potentially damaging effect of the c.944T>A replacement. In fact, this is the most probable reason why pigs with homozygous AA genotypes at the 944 site of the ASS1 coding region are alive. Our results illustrate the complexities of predicting the consequences of nonsense mutations on gene function and phenotypes, not only because of annotation issues but also owing to the existence of genetic mechanisms that sometimes limit the penetrance of highly harmful mutations

Inventaris de PCI: l'aplicació de la Convenció de la UNESCO

[cat]En aquest article, examinem com es concreta l'obligació de realitzar inventaris en lleis i pràctiques específiques en relació amb la Convenció per a la Salvaguarda del Patrimoni Cultural Immaterial. Volem conèixer els marcs jurídics i com integren els inventaris, comprendre'n les opcions adoptades i determinar-ne les repercussions. També volem analitzar com s'han traduït aquestes normes en projectes concrets d'inventari i com es fa front als reptes teòrics i metodològics que l'elaboració d'inventaris planteja.[eng]In this article we analyze the unfolding of inventories and specific practices recommended in the Convention for the Safeguarding of Intangible Cultural Heritage. We focus on how the variety of inventories in diverse countries is organized within specific juridical frames. We also pay attention to the different possibilities when drawing inventories and its implications. We will discuss this range of alternatives in inventorying Intangible Cultural Heritage and its theoretical and methodological impacts

The anticancer effect related to disturbances in redox balance on Caco-2 cells caused by an alkynyl gold(I) complex

The alkynyl gold(I) derivative Au(C=CPh)(PTA)] (PTA = 1, 3, 5-triaza-7-phosphaadamantane) induces apoptosis in colorectal carcinoma tumour cells (Caco-2) without affecting to normal enterocytes. Au(C=CPh)(PTA)] is a slight lipophilic drug, stable in PBS (Phosphate Buffered Saline) and able to bind BSA (Bovin Serum Albumin) by hydrophobic interactions. Once inside the cell, Au(C=CPh)(PTA)] targets seleno proteins such as Thioredoxin Reductase 1, increasing ROS (Reactive Oxygen Species) levels, reducing cell viability and proliferation and inducing mitochondrial apoptotic pathway, pro-apoptotic and anti-apoptotic protein imbalance, loss of mitochondrial membrane potential, cytochrome c release and activation of caspases 9 and 3. Moreover, unlike other metal-based drugs such as cisplatin, Au(C=CPh)(PTA)] does not target nucleic acid, reducing the risk of side mutation in the DNA. In consequence, our results predict a promising future for Au(C=CPh)(PTA)] as a chemotherapeutic agent for colorectal carcinoma

Phenolic composition of artichoke waste and its antioxidant capacity on differentiated Caco-2 cells

Artichoke waste represents a huge amount of discarded material. This study presents the by-products (bracts, exterior leaves, and stalks) of the “Blanca de Tudela” artichoke variety as a potential source of phenolic compounds with promising antioxidant properties. Artichoke residues were subjected to different extraction processes, and the antioxidant capacity and phenolic composition of the extracts were analyzed by spectrophotometric methods and high performance liquid chromatography (HPLC) analyses, respectively. The most abundant polyphenols in artichoke waste were chlorogenic acid, luteolin-7-O-rutinoside, and luteolin-7-O-glucoside. Minor quantities of cynarin, luteolin, apigenin-7-O-glucoside, apigenin-7-O-rutinoside, and naringenin-7-O-glucoside were also found. The antioxidant activity of the obtained extracts determined by ABTS [2, 2’-azinobis (3-ethylbenzothiazoline-6-sulphonic acid)], DPPH (2, 2-diphenyl-1-pycrilhydracyl), and FRAP (Ferric Ion Reducing Antioxidant Power) was highly correlated with the total concentration of phenolic compounds. Chlorogenic acid, luteolin-7-O-glucoside, and luteolin-7-O-rutinoside, the most abundant compounds in 60% methanol extracts, are the components most responsible for the antioxidant activity of the artichoke waste extracts. The extract with the best antioxidant capacity was selected to assay its antioxidant potential on a model intestinal barrier. This action of the hydroxycinnamic acids on intestinal cells (Caco-2) was confirmed. In summary, artichoke waste may be considered a very interesting ingredient for food functionalization and for therapeutic purposes

Ultrafine particles produced by plasma enhanced chemical vapor deposition -from SiH4, CH4, NH3 and B2H6 gas mixtures- for nanostructured ceramics applications

[eng] Ultrafine particles of silicon and related binary and ternary alloys of the Si-B-C-N system produced in our research group from silane, methane, diborane, ammonia and nitrogen precursor gases by plasma enhanced chemical vapor deposition at low pressure and room temperature are reviewed. The in-situ techniques of plasma analysis and surface characterization (quadrupolar mass spectrometry, optical emission spectroscopy and ellipsometry) providing evidence of powder formation and the polymerization reactions based on the SinH2n- negative radicals electrically confined in the plasma sheath are described. The square wave modulation (SQWM) of the rf power is discussed as an efficient method of controlling the powder particle production with low particle-size dispersion. The properties of the powder particles determined by different structural characterization techniques providing their size and distribution, crystalline order and morphology, chemical composition and chemical bond vibrational characteristics, are analyzed and discussed[cat] Hom presenta una revisió sobre les partícules ultrafines de silici i els seus aliatges binaris i ternaris del sistema Si-B-C-N, produïdes en el nostre grup de recerca a partir dels gasos precursors silà, metà, diborà, amoníac i nitrogen, per dipòsit químic en fase vapor (CVD) reforçat per plasma, a baixa pressió i temperatura ambient. És descrita també la utilització de tècniques in situ d'anàlisi per plasma i de caracterització de superfícies (espectroscòpia de masses quadripolar, espectroscòpia òptica d’emissió i el·lipsometria), que donaren l’evidència de formació de partícules de pols i de reaccions de polimerització basades en radicals negatius SinH2n– confinats elèctricament en l’embolcall del plasma. La modulació d’ona quadrada (SQWM) de la font de rf és estudiada com un eficient mètode de control de la producció de partícules amb una petita dispersió de llurs dimensions. Finalment, hom analitza i discuteix les propietats de les partícules produïdes, determinades per diferents tècniques de caracterització, que permeteren obtenir llurs dimensions i distribució, ordre cristal·lí i morfologia, composició química i les característiques vibracionals dels enllaços químic

Genomic analysis of the origins of extant casein variation in goats

The variation in the casein genes has a major impact on the milk composition of goats. Even though many casein polymorphisms have been identified so far, we do not know yet whether they are evolutionarily ancient (i.e., they existed before domestication) or young (i.e., they emerged after domestication). Herewith, we identified casein polymorphisms in a data set of 106 caprine whole-genome sequences corresponding to bezoars (Capra aegagrus, the ancestor of domestic goats) and 4 domestic goat (Capra hircus) populations from Europe, Africa, the Far East, and the Near East. Domestic and wild goat populations shared a substantial number of casein SNP, from 36.1% (CSN2) to 55.1% (CSN1S2). The comparison of casein variation among bezoars and the 4 domestic goat populations demonstrated that more than 50% of the casein SNP are shared by 2 or more populations, and 18 to 44% are shared by all populations. Moreover, the majority of casein alleles reported in domestic goats also segregate in the bezoar, including several alleles displaying significant associations with milk composition (e.g., the A/B alleles of the CSN1S1 and CSN3 genes, the A allele of the CSN2 gene). We conclude that much of the current diversity of the caprine casein genes comes from ancient standing variation segregating in the ancestor of modern domestic goats