Transient Ectopic Overexpression of Agouti-Signalling

While flatfish in the wild exhibit a pronounced countershading of the dorso-ventral pigment pattern, malpigmentation is commonly observed in reared animals. In fish, the dorso-ventral pigment polarity is achieved because a melanization inhibition factor (MIF) inhibits melanoblast differentiation and encourages iridophore proliferation in the ventrum. A previous work of our group suggested that asip1 is the uncharacterized MIF concerned. In order to further support this hypothesis, we have characterized asip1 mRNAs in both turbot and sole and used deduced peptide alignments to analyze the evolutionary history of the agouti-family of peptides. The putative asip precursors have the characteristics of a secreted protein, displaying a putative hydrophobic signal. Processing of the potential signal peptide produces mature proteins that include an N-terminal region, a basic central domain with a high proportion of lysine residues as well as a proline-rich region that immediately precedes the C-terminal poly-cysteine domain. The expression of asip1 mRNA in the ventral area was significantly higher than in the dorsal region. Similarly, the expression of asip1 within the unpigmented patches in the dorsal skin of pseudoalbino fish was higher than in the pigmented dorsal regions but similar to those levels observed in the ventral skin. In addition, the injection/electroporation of asip1 capped mRNA in both species induced long term dorsal skin paling, suggesting the inhibition of the melanogenic pathways. The data suggest that fish asip1 is involved in the dorsalventral pigment patterning in adult fish, where it induces the regulatory asymmetry involved in precursor differentiation into mature chromatophore. Adult dorsal pseudoalbinism seems to be the consequence of the expression of normal developmental pathways in an inaccurate position that results in unbalanced asip1 production levels. This, in turn, generates a ventral-like differentiation environment in dorsal regions.Publicado

The potential role of the adipokine HMGB1 in obesity and insulin resistance. Novel effects on adipose tissue biology

Discovery of the adipose tissue as a major source of signaling molecules almost three decades ago set a novel physiological paradigm that paved the way for the identification of metabolic organs as endocrine organs. Adipocytes, the main adipose tissue cell type, do not only represent the principal site of energy storage in form of triglycerides, but also produce a variety of molecules for short and long distance intercellular communication, named adipokines, which coordinate systemic responses. Although the best known adipokines identified and characterized hitherto are leptin and adiponectin, novel adipokines are continuously being described, what have significantly helped to elucidate the role of adipocyte biology in obesity and associated comorbidities. One of these novel adipokines is high-mobility group box 1 (HMGB1), a ubiquitous nuclear protein that has been recently reported to be dysregulated in obese dysfunctional adipocytes. Although the classical function of HMGB1 is related to inflammation and immunity, acting as an alarmin, novel advances evidence an active implication of HMGB1 in tissue remodeling and fibrosis. This review summarizes the current evidence on the mechanisms controlling HMGB1 release, as well as its role as a regulator of adipocyte function and extracellular matrix remodeling, with special emphasis on the potential of this novel adipokine as a target in the obesity treatment

Estudio biomecánico in vivo del grupo muscular flexor del codo en condiciones basales y su respuesta a la fatiga.

El objetivo del presente trabajo es establecer una aproximación al patrón de referencia habitual de la biomecánica del bíceps braquial y su respuesta a la fatiga. Sobre 37 voluntarios varones sanos se determinó una capacidad de contracción voluntaria máxima de flexión del codo de 266,8 ± 58,7N en el brazo dominante y de 258,2 ± 59,4N en el no dominante, que descendió a 211,5 ± 53N y 205,3 ± 56,5N respectivamente al someter a los voluntarios al test de fatiga (p<0,001 en ambos). El tiempo de fatiga se objetivó en 160,7 ± 72,8 s en el brazo dominante y en 156,7 ± 68,7 s en el no dominante. La supinación voluntaria máxima disminuyó de 208,7 ± 54N y 207 ± 54,8N hasta 194,1 ± 66,6N y 192,8 ± 66N respectivamente en el estudio postfatiga (p<0,001 en ambas). No se apreciaron diferencias significativas en el estudio de subgrupos por edades

Factores pronósticos del resultado de la quimionucleosis

Los resultados exitosos de la quimionucleosis dependen íntimamente de una estricta selección de los pacientes. En el presente trabajo se revisa la influencia de diferentes factores preoperatorios, clínicos y radiológicos, sobre el resultado de la quimionucleosis a los dos años de evolución, a través de un estudio estadístico de los casos. Los autores destacan como factores de mal pronóstico, en su casuística, las lumbalgias aisladas o prolongadas y el régimen laboral autónomo. Ni el tamaño ni la localizatción, central o lateral, de la imagen herniaria influyeron de manera estadística significativa en el resultado de la discolisis. Tampoco el número de discos explorados o inyectados, ni la presencia de signos radiológicos o tomodensitométricos asociados a la hernia discal sintomática.Successful results of chemonucleolysis depend specially on a strict patient selection. In this paper the influence of different preoperative, clinical and radiologic factors on the results two years after chemonucleolysis, is reviewed through the statistical analysis of the cases. The author s hav e observed the isolated or persistent low back pain (rather than sciatica), and being an autonomous worke r as poor prognosis factors in their environment. Size and site, either midline or lateral, of the disc herniation did not influence the results of chemonucleolysis with statistical significance; nor did the number of discs explored or injected, neither the presence of radiologic or tomodensitometric findings associated with symptomatic disc herniation

Mutations in blind cavefish target the light-regulated circadian clock gene, period 2

Light represents the principal signal driving circadian clock entrainment. However, how light influences the evolution of the clock remains poorly understood. The cavefish Phreatichthys andruzzii represents a fascinating model to explore how evolution under extreme aphotic conditions shapes the circadian clock, since in this species the clock is unresponsive to light. We have previously demonstrated that loss-of-function mutations targeting non-visual opsins contribute in part to this blind clock phenotype. Here, we have compared orthologs of two core clock genes that play a key role in photic entrainment, cry1a and per2, in both zebrafish and P. andruzzii. We encountered aberrantly spliced variants for the P. andruzzii per2 transcript. The most abundant transcript encodes a truncated protein lacking the C-terminal Cry binding domain and incorporating an intronic, transposon-derived coding sequence. We demonstrate that the transposon insertion leads to a predominantly cytoplasmic localization of the cavefish Per2 protein in contrast to the zebrafish ortholog which is distributed in both the nucleus and cytoplasm. Thus, it seems that during evolution in complete darkness, the photic entrainment pathway of the circadian clock has been subject to mutation at multiple levels, extending from opsin photoreceptors to nuclear effectors

Bases moleculares de las malformaciones pigmentarias en peces: implicación en el cultivo del rodaballo (Scophthalmus maximus L.)

In mammals the colour of skin is due to production of eumelanins (brown-black pigments) and pheomelanins (yellow-brownish pigments) in a specific type cell, the melanocytes. In contrast, in fish, pigmentation patternare determine by three different types of cells, melanophores, xantophores and iridophores. However, in both cases the melanogenesis is controlled by a similar mechanism. The α-MSH which stimulate the synthesis of melanin, and the ASP which antogonize its effects. Flounder (Scophthalmus maximus L.) agouti gen was cloned from skin tissue by using RACE-PCR with degenerated oligos. High expression of agouti gene was found in white epidermis areas compared with the black ones. Furthermore, dermal-injection of capped agouti mRNA produced a striking skin lightening. Thus, suggesting a central role of agouti gene in pigmentation pattern control in fish

Differential circadian and light-driven rhythmicity of clock gene expression and behaviour in the turbot, Scophthalmus maximus

In fish, the circadian clock represents a key regulator of many aspects of biology and is controlled by combinations of abiotic and biotic factors. These environmental factors are frequently manipulated in fish farms as part of strategies designed to maximize productivity. The flatfish turbot, Scophthalmus maximus, represents one of the most important species within the aquaculture sector in Asia and Europe. Despite the strategic importance of this species, the function and regulation of the turbot circadian system remains poorly understood. Here, we have characterized the core circadian clock genes, clock1, per1, per2 and cry1 in turbot and have studied their daily expression in various tissues under a range of lighting conditions and feeding regimes. We have also explored the influence of light and feeding time on locomotor activity. Rhythmic expression of the four core clock genes was observed in all tissues studied under light dark (LD) cycle conditions. Rhythmicity of clock gene expression persisted upon transfer to artificial free running, constant conditions confirming their endogenous circadian clock control. Furthermore, turbot showed daily cycles of locomotor activity and food anticipatory activity (FAA) under LD and scheduled-feeding, with the activity phase as well as FAA coinciding with and being dependent upon exposure to light. Thus, while FAA was absent under constant dark (DD) conditions, it was still detected in constant light (LL). In contrast, general locomotor activity was arrhythmic in both constant darkness and constant light, pointing to a major contribution of light, in concert with the circadian clock, in timing locomotor activity in this species. Our data represents an important contribution to our understanding of the circadian timing system in the turbot and thereby the optimization of rearing protocols and the improvement of the well-being of turbot within fish farming environments

Influence of Protein Carbonylation on Human Adipose Tissue Dysfunction in Obesity and Insulin Resistance

Background: Obesity is characterized by adipose tissue dysregulation and predisposes individuals to insulin resistance and type 2 diabetes. At the molecular level, adipocyte dysfunction has been linked to obesity-triggered oxidative stress and protein carbonylation, considering protein carbonylation as a link between oxidative stress and metabolic dysfunction. The identification of specific carbonylated proteins in adipose tissue could provide novel biomarkers of oxidative damage related to metabolic status (i.e prediabetes). Thus, we aimed at characterizing the subcutaneous and omental human adipose tissue carbonylome in obesity-associated insulin resistance. Methods: 2D-PAGE was used to identify carbonylated proteins, and clinical correlations studies and molecular biology approaches including intracellular trafficking, reactive oxygen species assay, and iron content were performed using in vitro models of insulin resistance. Results: The carbonylome of human adipose tissue included common (serotransferrin, vimentin, actin, and annexin A2) and depot-specific (carbonic anhydrase and α-crystallin B in the subcutaneous depot; and α-1-antitrypsin and tubulin in the omental depot) differences that point out the complexity of oxidative stress at the metabolic level, highlighting changes in carbonylated transferrin expression. Posterior studies using in vitro prediabetic model evidence alteration in transferrin receptor translocation, linked to the prediabetic environment. Finally, ligand-receptor molecular docking studies showed a reduced affinity for carbonylated transferrin binding to its receptor compared to wild-type transferrin, emphasizing the role of transferrin carbonylation in the link between oxidative stress and metabolic dysfunction. Conclusions: The adipose tissue carbonylome contributes to understanding the molecular mechanism driving adipocyte dysfunction and identifies possible adipose tissue carbonylated targets in obesity-associated insulin resistance

Copper-catalyzed diastereo- and enantioselective desymmetrization of cyclopropenes: Synthesis of cyclopropylboronates

This document is the accepted manuscript version of a Published Work that appeared in final form in Journal of American Chemical Society 136.45, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see DOI: 10.1021/ja510419zA novel Cu-catalyzed diastereo- and enantioselective desymmetrization of cyclopropenes to afford nonracemic cyclopropylboronates is described. Trapping the cyclopropylcopper intermediate with electrophilic amines allows for the synthesis of cyclopropylaminoboronic esters and demonstrates the potential of the approach for the synthesis of functionalized cyclopropanesWe thank the European Research Council (ERC-337776) and MINECO (CTQ2012-35957) for financial support. M. T. and A. P. thank MICINN for RyC and JdC contract