194 research outputs found

    The human Cranio Facial Development Protein 1 (Cfdp1) gene encodes a protein required for the maintenance of higher-order chromatin organization

    Get PDF
    The human Cranio Facial Development Protein 1 (Cfdp1) gene maps to chromosome 16q22.2-q22.3 and encodes the CFDP1 protein, which belongs to the evolutionarily conserved Bucentaur (BCNT) family. Craniofacial malformations are developmental disorders of particular biomedical and clinical interest, because they represent the main cause of infant mortality and disability in humans, thus it is important to understand the cellular functions and mechanism of action of the CFDP1 protein. We have carried out a multi-disciplinary study, combining cell biology, reverse genetics and biochemistry, to provide the first in vivo characterization of CFDP1 protein functions in human cells. We show that CFDP1 binds to chromatin and interacts with subunits of the SRCAP chromatin remodeling complex. An RNAi-mediated depletion of CFDP1 in HeLa cells affects chromosome organization, SMC2 condensin recruitment and cell cycle progression. Our findings provide new insight into the chromatin functions and mechanisms of the CFDP1 protein and contribute to our understanding of the link between epigenetic regulation and the onset of human complex developmental disorders

    Heterochromatin protein 1 (HP1) is associated with induced gene expression in Drosophila euchromatin

    Get PDF
    Heterochromatin protein 1 (HP1) is a conserved nonhistone chromosomal protein, which is involved in heterochromatin formation and gene silencing in many organisms. In addition, it has been shown that HP1 is also involved in telomere capping in Drosophila. Here, we show a novel striking feature of this protein demonstrating its involvement in the activation of several euchromatic genes in Drosophila. By immunostaining experiments using an HP1 antibody, we found that HP1 is associated with developmental and heat shock–induced puffs on polytene chromosomes. Because the puffs are the cytological phenotype of intense gene activity, we did a detailed analysis of the heat shock–induced expression of the HSP70 encoding gene in larvae with different doses of HP1 and found that HP1 is positively involved in Hsp70 gene activity. These data significantly broaden the current views of the roles of HP1 in vivo by demonstrating that this protein has multifunctional roles

    Anti-Inflammatory activity of a polyphenolic extract from Arabidopsis thaliana in in vitro and in vivo models of Alzheimer's Disease

    Get PDF
    Alzheimer's disease (AD) is the most common neurodegenerative disorder and the primary form of dementia in the elderly. One of the main features of AD is the increase in amyloid-beta (Aβ) peptide production and aggregation, leading to oxidative stress, neuroinflammation and neurodegeneration. Polyphenols are well known for their antioxidant, anti-inflammatory and neuroprotective effects and have been proposed as possible therapeutic agents against AD. Here, we investigated the effects of a polyphenolic extract of Arabidopsis thaliana (a plant belonging to the Brassicaceae family) on inflammatory response induced by Aβ. BV2 murine microglia cells treated with both Aβ25⁻35 peptide and extract showed a lower pro-inflammatory (IL-6, IL-1β, TNF-α) and a higher anti-inflammatory (IL-4, IL-10, IL-13) cytokine production compared to cells treated with Aβ only. The activation of the Nrf2-antioxidant response element signaling pathway in treated cells resulted in the upregulation of heme oxygenase-1 mRNA and in an increase of NAD(P)H:quinone oxidoreductase 1 activity. To establish whether the extract is also effective against Aβ-induced neurotoxicity in vivo, we evaluated its effect on the impaired climbing ability of AD Drosophila flies expressing human Aβ1⁻42. Arabidopsis extract significantly restored the locomotor activity of these flies, thus confirming its neuroprotective effects also in vivo. These results point to a protective effect of the Arabidopsis extract in AD, and prompt its use as a model in studying the impact of complex mixtures derived from plant-based food on neurodegenerative diseases

    the heterochromatin protein 1 positively regulates euchromatic gene expression by rna binding

    Get PDF
    HP1 is a well known conserved protein involved in heterochromatin formation and gene silencing in different species including humans1-4. A general model has been proposed for heterochromatin formation and epigenetic gene silencing in different species that implies an essential role for HP1. According to the model, histone methyltransferase enzymes (HMTases) methylate the histone H3 at lysine 9 (H3-MeK9), creating selective binding sites for itself and the chromodomain of HP15. This complex is thought to form a higher order chromatin state that represses gene activity. It has also been found that HP1 plays a role in telomere capping6. Surprisingly, recent data have suggested an association of HP1 in gene activity7-10 but the nature of this interaction is still completely obscure. Here we show, that HP1 is required for positive regulation of more than one hundred euchromatic genes by its association with the corresponding RNA transcripts and by its interaction with the well known proteins DDP111, HRB87F12 and PEP13, which belong to different classes of heterogeneous nuclear ribonucleoproteins (hnRNPs) involved in RNA processing . We also found that all these hnRNP proteins also bind heterochromatin and are dominant suppressors of position effect variegation. Our data together, show novel and unexpected functions for HP1 and hnRNPs proteins. All these proteins are in fact involved in both RNA transcript processing and in heterochromatin formation. This suggests that, in general, similar epigenetic mechanisms have a significant role in the metabolism of both RNA and heterochromatin

    Comparative Genomic Analyses Provide New Insights into the Evolutionary Dynamics of Heterochromatin in Drosophila

    Get PDF
    The term heterochromatin has been long considered synonymous with gene silencing, but it is now clear that the presence of transcribed genes embedded in pericentromeric heterochromatin is a conserved feature in the evolution of eukaryotic genomes. Several studies have addressed the epigenetic changes that enable the expression of genes in pericentric heterochromatin, yet little is known about the evolutionary processes through which this has occurred. By combining genome annotation analysis and high-resolution cytology, we have identified and mapped 53 orthologs of D. melanogaster heterochromatic genes in the genomes of two evolutionarily distant species, D. pseudoobscura and D. virilis. Our results show that the orthologs of the D. melanogaster heterochromatic genes are clustered at three main genomic regions in D. virilis and D. pseudoobscura. In D. virilis, the clusters lie in the middle of euchromatin, while those in D. pseudoobscura are located in the proximal portion of the chromosome arms. Some orthologs map to the corresponding Muller C element in D. pseudoobscura and D. virilis, while others localize on the Muller B element, suggesting that chromosomal rearrangements that have been instrumental in the fusion of two separate elements involved the progenitors of genes currently located in D. melanogaster heterochromatin. These results demonstrate an evolutionary repositioning of gene clusters from ancestral locations in euchromatin to the pericentromeric heterochromatin of descendent D. melanogaster chromosomes. Remarkably, in both D. virilis and D. pseudoobscura the gene clusters show a conserved association with the HP1a protein, one of the most highly evolutionarily conserved epigenetic marks. In light of these results, we suggest a new scenario whereby ancestral HP1-like proteins (and possibly other epigenetic marks) may have contributed to the evolutionary repositioning of gene clusters into heterochromatin

    The psychophysical impact that COVID-19 has on children must not be underestimated

    Get PDF
    Italy has been one of the European countries that has been most affected by the COVID\u201019 pandemic. By 16 April 2020, 159,107 Italian residents had tested positive for COVID\u201019 and these included 1,123 children, up to nine years of age (0.7%) and 1,804 adolescents, aged between 10 and 19 years old (1.1%) (1). These data were in line with the case studies reported for the Chinese population, where the respective percentage (proportion) was 0.9% and 1.2% respectively (2). A five\u2010year\u2010old Italian child, who had been affected by many previous and unspecified pathologies, died after testing positive for COVID\u201019 infection (1). The lower vulnerability of the paediatric population to COVID\u201019 seems eviden

    Drosophila CG3303 is an essential endoribonuclease linked to TDP-43-mediated neurodegeneration

    Get PDF
    Endoribonucleases participate in almost every step of eukaryotic RNA metabolism, acting either as degradative or biosynthetic enzymes. We previously identified the founding member of the Eukaryotic EndoU ribonuclease family, whose components display unique biochemical features and are flexibly involved in important biological processes, such as ribosome biogenesis, tumorigenesis and viral replication. Here we report the discovery of the CG3303 gene product, which we named DendoU, as a novel family member in Drosophila. Functional characterisation revealed that DendoU is essential for Drosophila viability and nervous system activity. Pan-neuronal silencing of dendoU resulted in fly immature phenotypes, highly reduced lifespan and dramatic motor performance defects. Neuron-subtype selective silencing showed that DendoU is particularly important in cholinergic circuits. At the molecular level, we unveiled that DendoU is a positive regulator of the neurodegeneration-associated protein dTDP-43, whose downregulation recapitulates the ensemble of dendoU-dependent phenotypes. This interdisciplinary work, which comprehends in silico, in vitro and in vivo studies, unveils a relevant role for DendoU in Drosophila nervous system physio-pathology and highlights that DendoU-mediated neurotoxicity is, at least in part, contributed by dTDP-43 loss-of-function

    The “Special” crystal-Stellate System in Drosophila melanogaster Reveals Mechanisms Underlying piRNA Pathway-Mediated Canalization

    Get PDF
    The Stellate-made crystals formation in spermatocytes is the phenotypic manifestation of a disrupted crystal-Stellate interaction in testes of Drosophila melanogaster. Stellate silencing is achieved by the piRNA pathway, but many features still remain unknown. Here we outline the important role of the crystal-Stellate modifiers. These have shed light on the piRNA pathways that defend genome integrity against transposons and other repetitive elements in the gonads. In particular, we illustrate the finding that HSP90 participates in the molecular pathways of piRNA production. This observation has relevance for the mechanisms underlying the evolutionary canalization process

    Progression of brain atrophy in spinocerebellar ataxia type 2: A longitudinal tensor-based morphometry study

    Get PDF
    Spinocerebellar ataxia type 2 (SCA2) is the second most frequent autosomal dominant inherited ataxia worldwide. We investigated the capability of magnetic resonance imaging (MRI) to track in vivo progression of brain atrophy in SCA2 by examining twice 10 SCA2 patients (mean interval 3.6 years) and 16 age- and gender-matched healthy controls (mean interval 3.3 years) on the same 1.5 T MRI scanner. We used T1-weighted images and tensor-based morphometry (TBM) to investigate volume changes and the Inherited Ataxia Clinical Rating Scale to assess the clinical deficit. With respect to controls, SCA2 patients showed significant higher atrophy rates in the midbrain, including substantia nigra, basis pontis, middle cerebellar peduncles and posterior medulla corresponding to the gracilis and cuneatus tracts and nuclei, cerebellar white matter (WM) and cortical gray matter (GM) in the inferior portions of the cerebellar hemisphers. No differences in WM or GM volume loss were observed in the supratentorial compartment. TBM findings did not correlate with modifications of the neurological deficit. In conclusion, MRI volumetry using TBM is capable of demonstrating the progression of pontocerebellar atrophy in SCA2, supporting a possible role of MRI as biomarker in future trials

    Consensus communication strategies to improve doctor-patient relationship in paediatric severe asthma

    Get PDF
    Background: Asthma is a chronic inflammatory disease that is very common among youth worldwide. The burden of this illness is very high not only considering financial costs but also on emotional and social functioning. Guidelines and many researches recommend to develop a good communication between physicians and children/caregiver and their parents. Nevertheless, a previous Italian project showed some criticalities in paediatric severe asthma management. The consensus gathered together experts in paediatric asthma management, experts in narrative medicine and patient associations with the aim of identify simple recommendation to improve communication strategies. Methods: Participants to the consensus received the results of the project and a selection of narratives two weeks before the meeting. The meeting was structured in plenary session and in three working groups discussing respectively about communication strategies with children, adolescents and parents. The task of each working group was to identify the most effective (DO) and least effective practices (DON' T) for 5 phases of the visit: welcome, comprehension of the context, emotions management, duration and end of the visit and endurance of the relationship. Results: Participants agreed that good relationships translate into positive outcomes and reached consensus on communication strategies to implement in the different phase of relationships. Conclusions: The future challenges identified by the participants are the dissemination of this Consensus document and the implementation of effective communication strategies to improve the management of pediatric asthma
    corecore