1,720,961 research outputs found
Molecular approaches for potential therapies in Ataxia Telangiectasia cellular model
Full text linkAtaxia Telangiectasia is a very rare severe pleiotropic neurodegenerative disease, with no currently available cure. Beneficial effects on neurologic features in AT patients have been described with dexamethasone (dex) administration by autologous erythrocytes EryDex in a phase II clinical trial, leading the researchers to explore the molecular mechanisms behind the drug action. For this purpose, in the attempt to explain dex outcomes in AT cells, we reported two novel biomolecular pathways specifically induced by dex in AT cells. The first one promotes a non-epigenetic function of HDAC4 and improves autophagy progression, a usually AT compromised pathway. The second one modulates Lamin A/C dynamics and its role in gene expression regulation, contributing to clarify the positive effects of dex in AT patients. Additionally, a simulation of patients’ treatment has been performed, revealing a differential gene expression variation between WT and AT cells. Afterwards, ATM variants, originated from alternative splicing of ATM messenger and detected in vivo in the blood of AT patients treated with EryDex, were characterized in fibroblast cell lines. We were able to describe their positive role in overcoming ATM absence in AT cells, supporting their capability in partially reversing AT phenotype and supporting their potential application for gene therapy for the treatment of AT patients and/or ATM mutations
Homemade tomato sauce in the Mediterranean Diet: a rich source of antioxidants protecting against postprandial oxidative stress.
No full textThe basic ingredients used to make the Italian soffritto were studied in order to define the
polyphenol, antioxidant capacity and lycopene content of homemade or commercial
tomato sauces, as well as their contribute in whole wheat or refined wheat pasta.
The addition of aromatic herbs to sauces increased polyphenols and antioxidant capacity,
with basil providing the biggest boost, whereas ready-made commercial tomato sauces
showed the lowest antioxidant values. Cooked whole wheat pasta with homemade tomato
sauce offers an enormous amount of antioxidants, which could protect against oxidative
stress
New human ATM variants are able to regain ATM functions in ataxia telangiectasia disease
Full text linkAtaxia telangiectasia is a rare neurodegenerative disease caused by biallelic mutations in the ataxia telangiectasia mutated gene. No cure is currently available for these patients but positive effects on neurologic features in AT patients have been achieved by dexamethasone administration through autologous erythrocytes (EryDex) in phase II and phase III clinical trials, leading us to explore the molecular mechanisms behind the drug action. During these investigations, new ATM variants, which originated from alternative splicing of ATM messenger, were discovered, and detected in vivo in the blood of AT patients treated with EryDex. Some of the new ATM variants, alongside an in silico designed one, were characterized and examined in AT fibroblast cell lines. ATM variants were capable of rescuing ATM activity in AT cells, particularly in the nuclear role of DNA DSBs recognition and repair, and in the cytoplasmic role of modulating autophagy, antioxidant capacity and mitochondria functionality, all of the features that are compromised in AT but essential for neuron survival. These outcomes are triggered by the kinase and further functional domains of the tested ATM variants, that are useful for restoring cellular functionality. The in silico designed ATM variant eliciting most of the functionality recover may be exploited in gene therapy or gene delivery for the treatment of AT patients
DDIT4 gene expression is switched on by a new HDAC4 function in ataxia telangiectasia
Full text linkAtaxia telangiectasia (AT) is a rare, severe, and ineluctably progressive multisystemic neurodegenerative disease. Histone deacetylase 4 (HDAC4) nuclear accumulation has been related to neurodegeneration in AT. Since treatment with glucocorticoid analogues has been shown to improve the neurological symptoms that characterize this syndrome, the effects of dexamethasone on HDAC4 were investigated. In this paper, we describe a novel nonepigenetic function of HDAC4 induced by dexamethasone, through which it can directly modulate HIF-1a activity and promote the upregulation of the DDIT4 gene and protein expression. This new HDAC4 transcription regulation mechanism leads to a positive effect on autophagic flux, an AT-compromised biological pathway. This signaling was specifically induced by dexamethasone only in AT cell lines and can contribute in explaining the positive effects of dexamethasone observed in AT-treated patients
The nucleoplasmic interactions among Lamin A/C-pRB-LAP2α-E2F1 are modulated by dexamethasone
Full text linkAtaxia telangiectasia (AT) is a rare genetic neurodegenerative disease. To date, there is no available cure for the illness, but the use of glucocorticoids has been shown to alleviate the neurological symptoms associated with AT. While studying the effects of dexamethasone (dex) in AT fibroblasts, by chance we observed that the nucleoplasmic Lamin A/C was affected by the drug. In addition to the structural roles of A-type lamins, Lamin A/C has been shown to play a role in the regulation of gene expression and cell cycle progression, and alterations in the LMNA gene is cause of human diseases called laminopathies. Dex was found to improve the nucleoplasmic accumulation of soluble Lamin A/C and was capable of managing the large chromatin Lamin A/C scaffolds contained complex, thus regulating epigenetics in treated cells. In addition, dex modified the interactions of Lamin A/C with its direct partners lamin associated polypeptide (LAP) 2a, Retinoblastoma 1 (pRB) and E2F Transcription Factor 1 (E2F1), regulating local gene expression dependent on E2F1. These effects were differentially observed in both AT and wild type (WT) cells. To our knowledge, this is the first reported evidence of the role of dex in Lamin A/C dynamics in AT cells, and may represent a new area of research regarding the effects of glucocorticoids on AT. Moreover, future investigations could also be extended to healthy subjects or to other pathologies such as laminopathies since glucocorticoids may have other important effects in these contexts as well
Transcriptomic profile of ataxia telangiectasia cells treated for 30 days with a low dose of dexamethasone
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Dexamethasone induces p21cip1/waf1 expression via FoxO3a independently of the Lamin A/C‐HDAC2 interaction in Ataxia Telangiectasia
No full textAtaxia‐Telangiectasia (A‐T) is a very rare autosomal recessive multisystemic disorder which to date is still uncurable. The use of glucocorticoid analogs, such as dexamethasone (dex), can improve neurological symptoms in patients, but the molecular mechanism of action of these analogs remains unclear. Here, we report the effects of dex in regulating the interaction between Lamin A/C and HDAC2 in WT and A‐T cells. Upon administration of dex to A‐T cells, we first observed that the accumulation of HDAC2 on the CDKN1A promoter did not exert a repressive role on p21cip1/waf1 expression, and second, we established that HDAC2 accumulation was not dependent on Lamin A/C. Both of these results are contrary to previous reported outcomes in other cellular models. Furthermore, large amounts of LAP2α and FoxO3a were found to occupy the CDKN1A promoter with matched p21cip1/waf1 overexpression. Hence, in A‐T cells p21 could be activated as a result of a dex‐induced rearrangement of a multicomponent complex, composed of Lamin A/C, HDAC2, LAP2α, pRb, E2F1, and FoxO3a, at the CDKN1A gene promoter
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