483 research outputs found

    PIK3CA mutations in vascular malformations

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    Purpose of the review: Recently, it has been discovered that a subset of vascular malformations, of the lymphatic and venous type, are caused by oncogenic mutations in the PIK3CA gene. Now, efforts have been focused in the understanding of the molecular and cellular consequences of these mutations and the opportunities for novel targeted therapies for these diseases. Recent findings: Here, we review the latest findings in the biology of oncogenic PIK3CA mutations in the pathogenesis of vascular malformations. We focus on the recent development of in vitro and in vivo tools for the study of PIK3CA-mutant vascular malformations with special interest in preclinical models for drug testing. Also, we review the latest advances in PI3K inhibitors in the clinic and their repurposing for the treatment of lymphatic malformations (LMs) and venous malformations (VMs). Summary: Oncogenic mutations on PIK3CA causing LMs and VMs are also frequently found in epithelial cancer. Thus, fundamental research done in the cancer field during the past decades might be applied to the understanding of LMs and VMs. Likewise, repurposing PI3K pathway inhibitors that are currently in cancer clinical trials can be used as a novel strategy for the treatment of these diseases. Here, we also open a debate for the consideration of LMs and VMs as developmental tumours

    Carbohydrate-Binding Non-Peptidic Pradimicins for the Treatment of Acute Sleeping Sickness in Murine Models

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    Current treatments available for African sleeping sickness or human African trypanosomiasis (HAT) are limited, with poor efficacy and unacceptable safety profiles. Here, we report a new approach to address treatment of this disease based on the use of compounds that bind to parasite surface glycans leading to rapid killing of trypanosomes. Pradimicin and its derivatives are non-peptidic carbohydrate-binding agents that adhere to the carbohydrate moiety of the parasite surface glycoproteins inducing parasite lysis in vitro. Notably, pradimicin S has good pharmaceutical properties and enables cure of an acute form of the disease in mice. By inducing resistance in vitro we have established that the composition of the sugars attached to the variant surface glycoproteins are critical to the mode of action of pradimicins and play an important role in infectivity. The compounds identified represent a novel approach to develop drugs to treat HAT.Funding: This work was supported by grants from the VI Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2008-2011, Instituto de Salud Carlos III - Subdirección General de Redes y Centros de Investigación Cooperativa, Red de Investigación Cooperativa en Enfermedades Tropicales (RICET) (RD06/0021), the Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016 (SAF2013-48999-R) (http://www.idi.mineco.gob.es), and the Junta de Andalucía (BIO-199, P09-CVI-5367) to DGP. Research of JB and SL was supported by the Katholieke Universiteit Leuven (PF 10/18). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

    A relação entre candomblé e escola no contexto brasileiro: uma revisão da literatura

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    Objective. Identify how the relationship between the between the Candomblé’s Terreiro and the school has been treated in the scientific literature, primarily by Developmental Psychology. Method. The articles were compiled in national (Brazil) and international databases and registered in the PRISMA matrix. After applying the inclusion and exclusion criteria, 23 articles were selected, which allowed the vertical and horizontal analysis of categories such as topics, publication area, methodologies, among others. Results. There is growing interest on the subject, primarily in Education and Social Sciences. Conclusion. Discrimination, prejudice and violence suffered by adherents of Afro-Brazilian religions are discussed. A vacuum has been identified on the subject in psychology magazines and on the development of subjective processes in the experience at the Terreiro and School border.Objetivo. Identificar cómo la relación entre el Terreiro de Candomblé y la escuela se viene tratando en la literatura científica, prioritariamente por la Psicología del Desarrollo. Método. Los artículos fueron recopilados en bases de datos nacionales (Brasil) e internacionales, y registrados en la matriz PRISMA. Después de aplicar los criterios de inclusión y exclusión, fueron seleccionados 23 artículos, lo que permitió el análisis vertical y horizontal de categorías como temas, área de publicación, metodologías, entre otros. Resultados. Hay interés creciente sobre el tema, prioritariamente, en Educación y Ciencias Sociales. Conclusión. Se discute sobre la discriminación, los prejuicios y la violencia sufridos por adeptos de las religiones afrobrasileñas. Se ha identificado un vacío sobre el tema en revistas de psicología y sobre el desarrollo de procesos subjetivos en la experiencia en la frontera terreiro y escuela.Escopo. Identificar como a relação entre o Terreiro de Candomblé e a escola tem sido tratada na literatura científica, principalmente pela Psicologia do Desenvolvimento. Método. Os artigos foram compilados em bases de dados nacionais (Brasil) e internacionais, e cadastrados na matriz PRISMA. Após aplicação dos critérios de inclusão e exclusão, foram selecionados 23 artigos, o que permitiu a análise vertical e horizontal de categorias como temas, área de publicação, metodologias, entre outras. Resultados. Há um interesse crescente pelo tema, principalmente na Educação e nas Ciências Sociais. Conclusão. Discute-se a discriminação, o preconceito e a violência sofrida pelos seguidores das religiões afro-brasileiras. Identificou-se uma lacuna sobre o tema nos periódicos de psicologia e sobre o desenvolvimento de processos subjetivos na experiência na fronteira do terreiro e da escola

    New genetic drivers in hemorrhagic hereditary telangiectasia. 

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    Background: Hereditary hemorrhagic telangiectasia (HHT) is a rare vascular disease inherited in an autosomal dominant manner. Disease-causing variants in endoglin (ENG) and activin A receptor type II-like 1 (ACVRL1) genes are detected in around 90% of the patients; also 2% of patients harbor pathogenic variants at SMAD4 and GDF2. Importantly, the genetic cause of 8% of patients with clinical HHT remains unknown. Here, we present new putative genetic drivers of HHT. Methods: To identify new HHT genetic drivers, we performed exome sequencing of 19 HHT patients and relatives with unknown HHT genetic etiology. We applied a multistep filtration strategy to catalog deleterious variants and prioritize gene candidates based on their known relevance in endothelial cell biology. Additionally, we performed in vitro validation of one of the identified variants. Results: We identified variants in the INHA, HIF1A, JAK2, DNM2, POSTN, ANGPTL4, FOXO1 and SMAD6 genes as putative drivers in HHT. We have identified the SMAD6 p.(Glu407Lys) variant in one of the families; this is a loss-of-function variant leading to the activation of the BMP/TGFβ signaling in endothelial cells. Conclusions: Variants in these genes should be considered for genetic testing in patients with HHT phenotype and negative for ACVRL1/ENG mutations

    Blockade of VEGF-C signaling inhibits lymphatic malformations driven by oncogenic PIK3CA mutation

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    Lymphatic malformations (LMs) are debilitating vascular anomalies presenting with large cysts (macrocystic) or lesions that infiltrate tissues (microcystic). Cellular mechanisms underlying LM pathology are poorly understood. Here we show that the somatic PIK3CA(H1047R) mutation, resulting in constitutive activation of the p110 alpha PI3K, underlies both macrocystic and microcystic LMs in human. Using a mouse model of PIK3CA(H1047R)-driven LM, we demonstrate that both types of malformations arise due to lymphatic endothelial cell (LEC)-autonomous defects, with the developmental timing of p110 alpha activation determining the LM subtype. In the postnatal vasculature, PIK3CA(H1047R) promotes LEC migration and lymphatic hypersprouting, leading to microcystic LMs that grow progressively in a vascular endothelial growth factor C (VEGF-C)-dependent manner. Combined inhibition of VEGF-C and the PI3K downstream target mTOR using Rapamycin, but neither treatment alone, promotes regression of lesions. The best therapeutic outcome for LM is thus achieved by co-inhibition of the upstream VEGF-C/VEGFR3 and the downstream PI3K/mTOR pathways. Lymphatic malformation (LM) is a debilitating often incurable vascular disease. Using a mouse model of LM driven by a disease-causative PIK3CA mutation, the authors show that vascular growth is dependent on the upstream lymphangiogenic VEGF-C signalling, permitting effective therapeutic intervention.Peer reviewe

    C/EBPβ Regulates TFAM Expression, Mitochondrial Function and Autophagy in Cellular Models of Parkinson’s Disease

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    Parkinson’s disease (PD) is a neurodegenerative disorder that results from the degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc). Since there are only symptomatic treatments available, new cellular and molecular targets involved in the onset and progression of this disease are needed to develop effective treatments. CCAAT/Enhancer Binding Protein β (C/EBPβ) transcription factor levels are altered in patients with a variety of neurodegenerative diseases, suggesting that it may be a good therapeutic target for the treatment of PD. A list of genes involved in PD that can be regulated by C/EBPβ was generated by the combination of genetic and in silico data, the mitochondrial transcription factor A (TFAM) being among them. In this paper, we observed that C/EBPβ overexpression increased TFAM promoter activity. However, downregulation of C/EBPβ in different PD/neuroinflammation cellular models produced an increase in TFAM levels, together with other mitochondrial markers. This led us to propose an accumulation of non-functional mitochondria possibly due to the alteration of their autophagic degradation in the absence of C/EBPβ. Then, we concluded that C/EBPβ is not only involved in harmful processes occurring in PD, such as inflammation, but is also implicated in mitochondrial function and autophagy in PD-like conditions.This research was supported by the “MINECO” (SAF2017-85199-P to A.P.C.), UCM-Santander (PR44/21-29931 to J.A.M.-G.) and the Health Institute “Carlos III” ( PI18/00118 to E.C. and PI21/00183 to F.B.). CIBERNED is funded by the Health Institute “Carlos III”. F.B. is a Miguel Servet Fellow (CP20/0007)

    Anti-IL-2 Treatment Impairs the Expansion of Treg Cell Population during Acute Malaria and Enhances the Th1 Cell Response at the Chronic Disease

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    Plasmodium chabaudi infection induces a rapid and intense splenic CD4+ T cell response that contributes to both disease pathogenesis and the control of acute parasitemia. The subsequent development of clinical immunity to disease occurs concomitantly with the persistence of low levels of chronic parasitemia. The suppressive activity of regulatory T (Treg) cells has been implicated in both development of clinical immunity and parasite persistence. To evaluate whether IL-2 is required to induce and to sustain the suppressive activity of Treg cells in malaria, we examined in detail the effects of anti-IL-2 treatment with JES6-1 monoclonal antibody (mAb) on the splenic CD4+ T cell response during acute and chronic P. chabaudi AS infection in C57BL/6 mice. JES6-1 treatment on days 0, 2 and 4 of infection partially inhibits the expansion of the CD4+CD25+Foxp3+ cell population during acute malaria. Despite the concomitant secretion of IL-2 and expression of high affinity IL-2 receptor by large CD4+ T cells, JES6-1 treatment does not impair effector CD4+ T cell activation and IFN-γ production. However, at the chronic phase of the disease, an enhancement of cellular and humoral responses occurs in JES6-1-treated mice, with increased production of TNF-α and parasite-specific IgG2a antibodies. Furthermore, JES6-1 mAb completely blocked the in vitro proliferation of CD4+ T cells from non-treated chronic mice, while it further increased the response of CD4+ T cells from JES6-1-treated chronic mice. We conclude that JES6-1 treatment impairs the expansion of Treg cell population during early P. chabaudi malaria and enhances the Th1 cell response in the late phase of the disease

    Location of chlorogenic acid biosynthesis pathway and polyphenol oxidase genes in a new interspecific anchored linkage map of eggplant

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    © Gramazio et al.; licensee BioMed Central. 2014. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated

    Immunochip analysis identifies multiple susceptibility loci for systemic sclerosis

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    In this study, 1,833 systemic sclerosis (SSc) cases and 3,466 controls were genotyped with the Immunochip array. Classical alleles, amino acid residues, and SNPs across the human leukocyte antigen (HLA) region were imputed and tested. These analyses resulted in a model composed of six polymorphic amino acid positions and seven SNPs that explained the observed significant associations in the region. In addition, a replication step comprising 4,017 SSc cases and 5,935 controls was carried out for several selected non-HLA variants, reaching a total of 5,850 cases and 9,401 controls of European ancestry. Following this strategy, we identified and validated three SSc risk loci, including DNASE1L3 at 3p14, the SCHIP1-IL12A locus at 3q25, and ATG5 at 6q21, as well as a suggested association of the TREH-DDX6 locus at 11q23. The associations of several previously reported SSc risk loci were validated and further refined, and the observed peak of association in PXK was related to DNASE1L3. Our study has increased the number of known genetic associations with SSc, provided further insight into the pleiotropic effects of shared autoimmune risk factors, and highlighted the power of dense mapping for detecting previously overlooked susceptibility loci
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