Transcriptomic differences in MSA clinical variants

Background: Multiple system atrophy (MSA) is a rare oligodendroglial synucleinopathy of unknown etiopathogenesis including two major clinical variants with predominant parkinsonism (MSA-P) or cerebellar dysfunction (MSA-C). Objective: To identify novel disease mechanisms we performed a blood transcriptomic study investigating differential gene expression changes and biological process alterations in MSA and its clinical subtypes. Methods: We compared the transcriptome from rigorously gender and age-balanced groups of 10 probable MSA-P, 10 probable MSA-C cases, 10 controls from the Catalan MSA Registry (CMSAR), and 10 Parkinson Disease (PD) patients. Results: Gene set enrichment analyses showed prominent positive enrichment in processes related to immunity and inflammation in all groups, and a negative enrichment in cell differentiation and development of the nervous system in both MSA-P and PD, in contrast to protein translation and processing in MSA-C. Gene set enrichment analysis using expression patterns in different brain regions as a reference also showed distinct results between the different synucleinopathies. Conclusions: In line with the two major phenotypes described in the clinic, our data suggest that gene expression and biological processes might be differentially affected in MSA-P and MSA-C. Future studies using larger sample sizes are warranted to confirm these results

Long non-coding RNA uc.291 controls epithelial differentiation by interfering with the ACTL6A/BAF complex.

The mechanisms that regulate the switch between epidermal progenitor state and differentiation are not fully understood. Recent findings indicate that the chromatin remodelling BAF complex (Brg1-associated factor complex or SWI/SNF complex) and the transcription factor p63 mutually recruit one another to open chromatin during epidermal differentiation. Here, we identify a long non-coding transcript that includes an ultraconserved element, uc.291, which physically interacts with ACTL6A and modulates chromatin remodelling to allow differentiation. Loss of uc.291 expression, both in primary keratinocytes and in three-dimensional skin equivalents, inhibits differentiation as indicated by epidermal differentiation complex genes down-regulation. ChIP experiments reveal that upon uc.291 depletion, ACTL6A is bound to the differentiation gene promoters and inhibits BAF complex targeting to induce terminal differentiation genes. In the presence of uc.291, the ACTL6A inhibitory effect is released, allowing chromatin changes to promote the expression of differentiation genes. Thus, uc.291 interacts with ACTL6A to modulate chromatin remodelling activity, allowing the transcription of late differentiation genes

By the company they keep: interaction networks define the binding ability of transcription factors

Access to genome-wide data provides the opportunity to address questions concerning the ability of transcription factors (TFs) to assemble in distinct macromolecular complexes. Here, we introduce the PAnDA (Protein And DNA Associations) approach to characterize DNA associations with human TFs using expression profiles, protein-protein interactions and recognition motifs. Our method predicts TF binding events with >0.80 accuracy revealing cell-specific regulatory patterns that can be exploited for future investigations. Even when the precise DNA-binding motifs of a specific TF are not available, the information derived from protein-protein networks is sufficient to perform high-confidence predictions (area under the ROC curve of 0.89). PAnDA is freely available at http://service.tartaglialab.com/new_submission/panda.The research leading to these results has received funding from the European Research Council under the European/nUnion’s Seventh Framework Programme (FP7/2007-2013)/ ERC grant agreementRIBOMYLOME 309545; the Fundació La Marató de TV3 (20142731); and the Spanish Ministry of Economy and Competitiveness, ‘Centro de Excelencia Severo Ochoa 2013-2017’ (SEV-2012-0208). Funding for Open Access charge: European Union’s Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement RIBOMYLOME 309545 and Spanish Ministry of Economy and Competitiveness, ‘Centro de Excelencia Severo Ochoa 2013-2017’ (SEV-2012-0208)

Molecular pathophysiology of fragile x-associated tremor/ataxia syndrome and perspectives for drug development

Fragile X-associated tremor/ataxia syndrome (FXTAS) is an inherited neurodegenerative disorder manifesting in carriers of 55 to 200 CGG repeats in the 5' untranslated region (UTR) of the fragile X mental retardation gene (FMR1). FXTAS is characterized by enhanced FMR1 transcription and the accumulation of CGG repeat-containing FMR1 messenger RNA in nuclear foci, while the FMRP protein expression levels remain normal or moderately low. The neuropathological hallmark in FXTAS is the presence of intranuclear, ubiquitin-positive inclusions that also contain FMR1 transcript. Yet, the complete protein complement of FXTAS inclusions and the molecular events that trigger neuronal death in FXTAS remain unclear. In this review, we present the two most accepted toxicity mechanisms described so far, namely RNA gain-of-function and protein gain-of-function by means of repeat-associated non-AUG translation, and discuss current experimental and computational strategies to better understand FXTAS pathogenesis. Finally, we review the current perspectives for drug development with disease-modifying potential for FXTAS.Our research received funding from the European Union Seventh Framework Programme (FP7/2007-2013), through the European Research Council, under grant agreement RIBOMYLOME_ 309545 (Gian Gaetano Tartaglia), and from the Fundació La Marató de TV3 (20142731). We also acknowledge support from the Spanish Ministry of Economy and Competitiveness (BFU2011-26206 and BFU2014-55054-P) and “Centro de Excelencia Severo Ochoa 2013– 2017” (SEV-2012-0208

By the company they keep: interaction networks define the binding ability of transcription factors

Access to genome-wide data provides the opportunity to address questions concerning the ability of transcription factors (TFs) to assemble in distinct macromolecular complexes. Here, we introduce the PAnDA (Protein And DNA Associations) approach to characterize DNA associations with human TFs using expression profiles, protein-protein interactions and recognition motifs. Our method predicts TF binding events with >0.80 accuracy revealing cell-specific regulatory patterns that can be exploited for future investigations. Even when the precise DNA-binding motifs of a specific TF are not available, the information derived from protein-protein networks is sufficient to perform high-confidence predictions (area under the ROC curve of 0.89). PAnDA is freely available at http://service.tartaglialab.com/new_submission/panda.The research leading to these results has received funding from the European Research Council under the European/nUnion’s Seventh Framework Programme (FP7/2007-2013)/ ERC grant agreementRIBOMYLOME 309545; the Fundació La Marató de TV3 (20142731); and the Spanish Ministry of Economy and Competitiveness, ‘Centro de Excelencia Severo Ochoa 2013-2017’ (SEV-2012-0208). Funding for Open Access charge: European Union’s Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement RIBOMYLOME 309545 and Spanish Ministry of Economy and Competitiveness, ‘Centro de Excelencia Severo Ochoa 2013-2017’ (SEV-2012-0208)

Neurodegeneration and cancer: where the disorder prevails

It has been reported that genes up-regulated in cancer are often down-regulated in neurodegenerative disorders and vice versa. The fact that apparently unrelated diseases share functional pathways suggests a link between their etiopathogenesis and the properties of molecules involved. Are there specific features that explain the exclusive association of proteins with either cancer or neurodegeneration? We performed a large-scale analysis of physico-chemical properties to understand what characteristics differentiate classes of diseases. We found that structural disorder significantly distinguishes proteins up-regulated in neurodegenerative diseases from those linked to cancer. We also observed high correlation between structural disorder and age of onset in Frontotemporal Dementia, Parkinson's and Alzheimer's diseases, which strongly supports the role of protein unfolding in neurodegenerative processes.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013), through the European Research Council, under grant agreement RIBOMYLOME_309545 (Gian Gaetano Tartaglia), and from the Fundació La Marató de TV3 (20142731). We also acknowledge support from AGAUR (2014 SGR00685) and the Spanish Ministry of Economy and Competitiveness (BFU2014-55054-P), ‘Centro de Excelencia Severo Ochoa 2013-2017′ (SEV-2012-0208

Neurodegeneration and cancer: where the disorder prevails

It has been reported that genes up-regulated in cancer are often down-regulated in neurodegenerative disorders and vice versa. The fact that apparently unrelated diseases share functional pathways suggests a link between their etiopathogenesis and the properties of molecules involved. Are there specific features that explain the exclusive association of proteins with either cancer or neurodegeneration? We performed a large-scale analysis of physico-chemical properties to understand what characteristics differentiate classes of diseases. We found that structural disorder significantly distinguishes proteins up-regulated in neurodegenerative diseases from those linked to cancer. We also observed high correlation between structural disorder and age of onset in Frontotemporal Dementia, Parkinson's and Alzheimer's diseases, which strongly supports the role of protein unfolding in neurodegenerative processes.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013), through the European Research Council, under grant agreement RIBOMYLOME_309545 (Gian Gaetano Tartaglia), and from the Fundació La Marató de TV3 (20142731). We also acknowledge support from AGAUR (2014 SGR00685) and the Spanish Ministry of Economy and Competitiveness (BFU2014-55054-P), ‘Centro de Excelencia Severo Ochoa 2013-2017′ (SEV-2012-0208

In silico, in vitro, and in vivo approaches to identify molecular players in fragile X tremor and ataxia syndrome

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative monogenetic disorder affecting carriers of premutation (PM) forms of the FMR1 gene, resulting in a progressive development of tremors, ataxia, and neuropsychological problems. This highly disabling disease is quite common in the general population with an estimation of about 20 million PM carriers worldwide. The chances of developing FXTAS increase dramatically with age, with about 45% of male carriers over the age of 50 being affected. Both the gene and pathogenic trigger, a mutant expansion of CGG RNA, causing FXTAS are known. This makes it an interesting disease to develop targeted therapeutic interventions for. Yet, no such interventions are available at this moment. Here we discuss in silico, in vitro, and in vivo approaches and how they have been used to identify the molecular determinants of FXTAS pathology. These approaches have yielded substantial information about FXTAS pathology and, consequently, many markers have emerged to play a key role in understanding the disease mechanism. Integration of the different approaches is expected to provide crucial information about the value of these markers as either therapeutic target or biomarker, essential to monitor therapeutic interventions in the future.The research leading to these results has been supported by the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) ERC grant agreement RIBOMYLOME_309545 to GT and ASTRA 855923 to GT, the Spanish Ministry of Science and Innovation (AEI/ERDF, BFU2014-55054-P and BFU2017-86970-P) and the ‘Fundació La Marató de TV3’ (PI043296

Constitutive patterns of gene expression regulated by RNA-binding proteins

Background: RNA-binding proteins regulate a number of cellular processes, including synthesis, folding, translocation, assembly and clearance of RNAs. Recent studies have reported that an unexpectedly large number of proteins are able to interact with RNA, but the partners of many RNA-binding proteins are still uncharacterized. Results: We combined prediction of ribonucleoprotein interactions, based on catRAPID calculations, with analysis of protein and RNA expression profiles from human tissues. We found strong interaction propensities for both positively and negatively correlated expression patterns. Our integration of in silico and ex vivo data unraveled two major types of protein–RNA interactions, with positively correlated patterns related to cell cycle control and negatively correlated patterns related to survival, growth and differentiation. To facilitate the investigation of protein–RNA interactions and expression networks, we developed the catRAPID express web server. Conclusions: Our analysis sheds light on the role of RNA-binding proteins in regulating proliferation and differentiation processes, and we provide a data exploration tool to aid future experimental studies.Our work was supported by the Ministerio de Economía y Competividad (SAF2011-26211 to GGT) and the European Research Council (ERC Starting Grant to GGT). DM is supported by the Programa de Ayudas FPI del Ministerio de Economía y Competitividad BES-2012-05245

Microarray expression analysis in idiopathic and LRRK2-associated Parkinson's disease

LRRK2 mutations are the most common genetic cause of Parkinson's disease (PD). We performed a whole-genome RNA profiling of putamen tissue from idiopathic PD (IPD), LRRK2-associated PD (G2019S mutation), neurologically healthy controls and one asymptomatic LRRK2 mutation carrier, by using the Genechip Human Exon 1.0-ST Array. The differentially expressed genes found in IPD revealed an alteration of biological pathways related to long-term potentiation (LTP), GABA receptor signalling, and calcium signalling pathways, among others. These pathways are mainly related with cell signalling cascades and synaptic plasticity processes. They were also altered in the asymptomatic LRRK2 mutation carrier but not in the LRRK2-associated PD group. The expression changes seen in IPD might be attributed to an adaptive consequence of a dysfunction in the dopamine transmission. The lack of these altered molecular pathways in LRRK2-associated PD patients suggests that these cases could show a different molecular response to dopamine transmission impairment. © 2011 Elsevier Inc.This project was supported by grants from 2001SRG00387 Generalitat de Catalunya, the award 'Distinció per la promoció de la Recerca Universitària de la Generalitat de Catalunya' to Dr. Eduard Tolosa, and grants from Fondo de Investigaciones Sanitarias to Dr. Mario Ezquerra (U-2004-FS041184-O). Dr. Alex Sanchez-Pla is partially supported by grant from the Ministerio de Educación y Ciencia (MTM2008-00642). Teresa Botta-Orfila is recipient of a predoctoral grant from IDIBAPS.Peer Reviewe