Archive for March, 2010

A recent study published in Nature Neuroscience reveals that excess glycogen induces neuronal death and causes a fatal kind of epilepsy that affects adolescents. This previously unknown mechanism could be key to understanding other neurodegenerative diseases, as is clear from research coordinated by Joan Guinovart Institute of Research in Biomedicine (IRB Barcelona) and Santiago Rodríguez de Córdoba Biological Research Center of CSIC . Read the rest of this entry »

Complications associated with obesity stands out for its special relevance to the development of insulin resistance in skeletal muscle, the first link in a broad condition known as type II diabetes. It has been proposed to adipocitokine TNF-α as the link between obesity and the development of insulin resistance, which is a defect in signaling of the same at various levels. In this study, led by Margarita Lorenzo, Faculty of Pharmacy of the Complutense University of Madrid, has identified the tyrosine phosphatase PTP1B, a negative regulator of insulin signaling, as a target of action of TNF-α.


Treatment with adipocitokine increases, both in myocytes and in skeletal muscle, the expression and activity of this phosphatase. Since for PTP1B gene deletion mice were generated immortalized myocyte lines showing increased insulin sensitivity with respect to the wild lines and do not develop resistance to it by TNF-α.


The study also describes that PTP1B deficiency confers protection in mice when subjected to the tests of glucose tolerance and insulin after treatment with adipocitokine. In conclusion, modulation of genes such as PTP1B may contribute to the pathogenesis caused by TNF-α in skeletal muscle, and genetic ablation of PTP1B in this tissue may confer protection against insulin resistance by this adipocitokine.

Three years ago, Eduard Batlle is ICREA research professor of the Generalitat de Catalunya and the principal investigator and coordinator of the Translational Oncology Program and the Institute of Applied biomedical research in Barcelona (IRB Barcelona). It has a complete history that includes extended periods of research in leading laboratories in oncology: completed his doctoral thesis at the Municipal Institute of Medical Research (IMIM) in 1999, spent nearly two years of postdoctoral researcher in the group in Germany and Miguel Beato four more in the Netherlands Institute for Developmental Biology. Read the rest of this entry »

The presence of competing plants in the physical proximity is perceived in terms of reducing the proportion of red light (R, English network) and far-red (FR, far-red English), or ratio R: FR, the incident radiation. Anticipating shaded by other plants, the perception of low light ratio R: FR, conducted by the photoreceptor phytochrome, launches the so-called syndrome escape from the shadow “(SAS, its acronym in English), a stimulating set of responses, including the longitudinal growth at the expense of the accumulation of photoassimilates in harvestable organs, or bloom.


At the molecular level, the implementation of SAS induces rapid changes in gene expression. In this work, coordinated by Professor Martinez-Garcia, has addressed the role of PAR1 and PAR2 (Rapidly Phytochrome Regulated), two Arabidopsis genes whose expression is induced rapidly after the perception of plant proximity. These two genes encode proteins atypical family of transcription factors of the type bHLH (basic-helix-loop-helix). Using genetic strategies has shown that PAR1 and PAR2 in the nucleus act as negative regulators of SAS.


From a molecular standpoint, PAR1 and PAR2 act as direct transcriptional repressors of the expression of two auxin-responsive genes, and SAUR68 SAUR15 (Small Auxin upregulated). The absence of a conserved domain of DNA binding proteins in PAR1 and PAR2 implies that they regulate gene expression not directly but by modulating the DNA binding of transcription factors to interact through the HLH domain, acting as transcriptional cofactors.
Taken together, these results led to propose that these small atypical bHLH proteins would connect quickly the perception of the shadow by phytochromes and sensitivity to hormones, integrating the relevant transcriptional networks in plants.

Given the endless accumulation of complete genomes of a remarkable number of organisms, one of the immediate objectives of the post-genomic era is the functional description of all the genes that make up a genome. To this end, considerable effort has focused on experimental design methods with high analytical skills. Among them, induction of variation in the expression of cDNA libraries, which are tested in cell cultures. Along with this approach, the development of robotic systems provides massive data analysis and a multitude of variables taken together . Read the rest of this entry »

AKR1B10 is a aldocetoreductasa (AKR) especially interesting for two reasons: it is overexpressed in lung cancer and precancerous lesions of smokers and becomes very efficient, the retinal to retinol, retinal reductase being the most active among AKR. Researchers from the Universitat Autònoma de Barcelona, IBMB, IRB Barcelona, and Universidade De Vigo CRQT propose that both features could be related through the alteration of the signaling pathway of retinoic acid. This compound, synthesized by successive oxidation of retinol (vitamin A) to retinal, and thence to acid molecule is a potent regulator of differentiation celular.Una AKR1B10 high expression, potentially induced by snuff, would result in a significant decrease retinal cell levels and, consequently, retinoic acid, which could lead to lack of differentiation, and induce cancer cell proliferation and . Read the rest of this entry »

The gene hedgehog (hh) was initially identified as a key gene in embryonic development of the fruit fly, Drosophila melanogaster. While Drosophila has only one hedgehog gene, vertebrates have three peers. These proteins are secreted extracellular ligands by a group of cells during organ formation in the embryo. In the adult hedgehog maintains and regulates stem cells in many tissues, being instrumental in regenerative processes. There is also a close relation between HH signaling pathway and the development of tumors, genetic alterations observed that stimulate the growth of tumor cells in the digestive tract, lung and prostate .