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Costa Valles C.,Bellvitge Institute for Biomedical Research IDIBELL | Manez Mendiluce R.,Bellvitge University Hospital
Advances in Experimental Medicine and Biology | Year: 2012

A dvances in immunosuppressive treatments reached in the last decades of the 20th century have made solid organ transplantation the treatment of choice for cases of irreversible organ failure. However, the availability of human cadaver organs is limited and the demand for transplants is still on the rise. Also, there is a recognised lack of cells and human tissues for generalised use in transplantation for the treatment of diseases that are characterised by failure of specialised cells (such as pancreatic cells to cure diabetes). Xenotransplantation, which is the transplant of cells, tissues or organs from other species, became the focus of attention in the nineteen-nineties as a solution to the lack of organs and tissues for transplantation. Previous clinical studies using nonhuman primates produced poor outcomes (survival from days to a few months) and confirmed the difficulty of obtaining organs from these species. Since then, progress in xenotransplantation has been slow and still now various immunological and non-immunological barriers need to be overcome. These barriers are reviewed in this chapter and the various approaches explored to date to overcome them, in particular those based on the genetic modification of pigs. Also, cell transplant studies such as those of pancreatic islets in monkeys have led to even more hopeful results. The range of possibilities offered by this technology will be unlimited, making it possible for xenotransplantation to be a clinical reality in a not very distant future. © 2012 Landes Bioscience and Springer Science+Business Media.

Izquierdo-Serra M.,Institute for Bioengineering of Catalonia IBEC | Trauner D.,Ludwig Maximilians University of Munich | Llobet A.,Bellvitge Institute for Biomedical Research IDIBELL | Gorostiza P.,Institute for Bioengineering of Catalonia IBEC | And 2 more authors.
Frontiers in Molecular Neuroscience | Year: 2013

A wide range of light-activated molecules (photoswitches and phototriggers) have been used to the study of computational properties of an isolated neuron by acting pre and postsynaptically. However, new tools are being pursued to elicit a presynaptic calcium influx that triggers the release of neurotransmitters, most of them based in calciumpermeable Channelrhodopsin-2 mutants. Here we describe a method to control exocytosis of synaptic vesicles through the use of a light-gated glutamate receptor (LiGluR), which has recently been demonstrated that supports secretion by means of calcium influx in chromaffin cells. Expression of LiGluR in hippocampal neurons enables reversible control of neurotransmission with light, and allows modulating the firing rate of the postsynaptic neuron with the wavelength of illumination. This method may be useful for the determination of the complex transfer function of individual synapses. © 2013 Izquierdo-serra, Trauner, Llobet and Gorostiza.

Iglesias-Platas I.,Servicio de Neonatologa | Court F.,Bellvitge Institute for Biomedical Research IDIBELL | Camprubi C.,Bellvitge Institute for Biomedical Research IDIBELL | Camprubi C.,Autonomous University of Barcelona | And 8 more authors.
Nucleic Acids Research | Year: 2013

Paternal duplications of chromosome 6q24, a region that contains the imprinted PLAGL1 and HYMAI transcripts, are associated with transient neonatal diabetes mellitus. A common feature of imprinted genes is that they tend to cluster together, presumably as a result of sharing common cis-Acting regulatory elements. To determine the extent of this imprinted cluster in human and mouse, we have undertaken a systematic analysis of allelic expression and DNA methylation of the genes mapping within an ∼1.4-Mb region flanking PLAGL1/Plagl1. We confirm that all nine neighbouring genes are biallelically expressed in both species. In human we identify two novel paternally expressed PLAGL1 coding transcripts that originate from unique promoter regions. Chromatin immunoprecipitation for CTCF and the cohesin subunits RAD21 and SMC3 reveals evolutionarily conserved binding sites within unmethylated regions ∼ 5 kb downstream of the PLAGL1 differentially methylated region and within the PLAGL1 30 untranslated region (UTR). Higher-order chromatin looping occurs between these regions in both expressing and non-expressing tissues, forming a non-Allelic chromatin loop around the PLAGL1/Plagl1 gene. In placenta and brain tissues, we identify an additional interaction between the PLAGL1 P3/P4 promoters and the unmethylated element downstream of the PLAGL1 differentially methylated region that we propose facilitates imprinted expression of these alternative isoforms. © The Author(s) 2013.

Nagy L.G.,University of Szeged | Hazi J.,University of Szeged | Szappanos B.,Hungarian Academy of Sciences | Kocsube S.,University of Szeged | And 4 more authors.
Systematic Biology | Year: 2012

Bursts of diversification are known to have contributed significantly to the extant morphological and species diversity, but evidence for many of the theoretical predictions about adaptive radiations have remained contentious. Despite their tremendous diversity, patterns of evolutionary diversification and the contribution of explosive episodes in fungi are largely unknown. Here, using the genus Coprinellus (Psathyrellaceae, Agaricales) as a model, we report the first explosive fungal radiation and infer that the onset of the radiation correlates with a change from a multilayered to a much simpler defense structure on the fruiting bodies. We hypothesize that this change constitutes a key innovation, probably relaxing constraints on diversification imposed by nutritional investment into the development of protective tissues of fruiting bodies. Fossil calibration suggests that Coprinellus mushrooms radiated during the Miocene coinciding with global radiation of large grazing mammals following expansion of dry open grasslands. In addition to diversification rate-based methods, we test the hard polytomy hypothesis, by analyzing the resolvability of internal nodes of the backbone of the putative radiation using Reversible-Jump MCMC. We discuss potential applications and pitfalls of this approach as well as how biologically meaningful polytomies can be distinguished from alignment shortcomings. Our data provide insights into the nature of adaptive radiations in general by revealing a deceleration of morphological diversification through time. The dynamics of morphological diversification was approximated by obtaining the temporal distribution of state changes in discrete traits along the trees and comparing it with the tempo of lineage accumulation. We found that the number of state changes correlate with the number of lineages, even in parts of the tree with short internal branches, and peaks around the onset of the explosive radiation followed by a slowdown, most likely because of the decrease in available niches. © 2012 The Author(s).

Berdasco M.,Bellvitge Institute for Biomedical Research IDIBELL | Esteller M.,Bellvitge Institute for Biomedical Research IDIBELL | Esteller M.,Catalan Institution for Research and Advanced Studies
Developmental Cell | Year: 2010

Appropriate patterns of DNA methylation and histone modifications are required to assure cell identity, and their deregulation can contribute to human diseases, such as cancer. Our aim here is to provide an overview of how epigenetic factors, including genomic DNA methylation, histone modifications, and microRNA regulation, contribute to normal development, paying special attention to their role in regulating tissue-specific genes. In addition, we summarize how these epigenetic patterns go awry during human cancer development. The possibility of " resetting" the abnormal cancer epigenome by applying pharmacological or genetic strategies is also discussed. © 2010 Elsevier Inc.

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