1,721,040 research outputs found
Transcriptomic profile of ataxia telangiectasia cells treated for 30 days with a low dose of dexamethasone
No full textThe 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
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
Label-free quantification of Tacrolimus in biological samples by atomic force microscopy
No full textIn the present paper we describe an atomic force microscopy (AFM)-based method for the quantitative
analysis of FK506 (Tacrolimus) in whole blood (WB) samples. Current reference methods used to quantify
this immunosuppressive drug are based on mass spectrometry. In addition, an immunoenzymatic assay
(ELISA) has been developed and is widely used in clinic, even though it shows a small but consistent
overestimation of the actual drug concentrationwhen compared with themass spectrometrymethod. The
AFM biosensor presented herein utilises the endogen drug receptor, FKBP12, to quantify Tacrolimus levels.
The biosensor was first assayed to detect the free drug in solution, and subsequently used for the detection
of Tacrolimus in blood samples. The sensor was suitable to generate a dose–response curve in the full range
of clinical drug monitoring. A comparison with the clinically tested ELISA assay is also reporte
Ubiquitin over-expression promotes E6AP degradation and reactivation of the p53/mdm-2 pathway
No full text32nd FEBS Congress, Molecular Machine
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
AFM evaluation of a humanized recombinant antibody affecting C. auris cell wall and stability
No full text: Fungal infections are increasingly impacting on the health of the population and particularly on subjects with a compromised immune system. The resistance phenomenon and the rise of new species carrying sometimes intrinsic and multi-drug resistance to the most commonly used antifungal drugs are greatly concerning healthcare organizations. As a result of this situation, there is growing interest in the development of therapeutic agents against pathogenic fungi. In particular, the Candida genus is responsible for severe life-threatening infections and among its species, C. auris is considered an urgent threat by the Center for Disease Control and Prevention, and is one of the three leading causes of morbidity and mortality worldwide. H5K1 is a humanized monoclonal antibody (hmAb) that selectively binds to β-1,3-glucans, vital components of the fungal cell wall. It has been previously demonstrated that it is active against Candida species, especially against C. auris, reaching its greatest potential when combined with commercially available antifungal drugs. Here we used atomic force microscopy (AFM) to assess the effects of H5K1, alone and in combination with fluconazole, caspofungin and amphotericin B, on C. auris cells. Through an extensive exploration we found that H5K1 has a significant role in the perturbation and remodeling of the fungal cell wall that is reflected in the loss of whole cell integrity. Moreover, it contributes substantially to the alterations in terms of chemical composition, stiffness and roughness induced specifically by caspofungin and amphotericin B. In addition to this, we demonstrated that AFM is a valuable technique to evaluate drug-microorganism interaction
MOLECULAR CLONING OF THE SMALL GTPASE CDC42 AND RHO-GDI GENES INVOLVED IN THE ACTIN CYTOSKELETON DEVELOPMENT IN THE ECTOMYCORRHIZAL FUNGUS T. BORCHII VITTAD
No full textMagnetic capture hybridization technology: a new tool for selective isolation of cell-free circulating DNA from human plasma
No full textDexamethasone 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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