Epigenetic control of EMT/MET dynamics: HNF4α impacts DNMT3s through miRs-29

Background and aims: Epithelial-to-mesenchymal transition (EMT) and the reverse mesenchymal-to-epithelial transition (MET) are manifestations of cellular plasticity that imply a dynamic and profound gene expression reprogramming. While a major epigenetic code controlling the coordinated regulation of a whole transcriptional profile is guaranteed by DNA methylation, DNA methyltransferase (DNMT) activities in EMT/MET dynamics are still largely unexplored. Here, we investigated the molecular mechanisms directly linking HNF4α, the master effector of MET, to the regulation of both de novo of DNMT 3A and 3B. Methods: Correlation among EMT/MET markers, microRNA29 and DNMT3s expression was evaluated by RT-qPCR, Western blotting and immunocytochemical analysis. Functional roles of microRNAs and DNMT3s were tested by anti-miRs, microRNA precursors and chemical inhibitors. ChIP was utilized for investigating HNF4α DNA binding activity. Results: HNF4α silencing was sufficient to induce positive modulation of DNMT3B, in in vitro differentiated hepatocytes as well as in vivo hepatocyte-specific Hnf4α knockout mice, and DNMT3A, in vitro, but not DNMT1. In exploring the molecular mechanisms underlying these observations, evidence have been gathered for (i) the inverse correlation between DNMT3 levels and the expression of their regulators miR-29a and miR- 29b and (ii) the role of HNF4α as a direct regulator of miR-29a-b transcription. Notably, during TGFβ-induced EMT, DNMT3s' pivotal function has been proved, thus suggesting the need for the repression of these DNMTs in the maintenance of a differentiated phenotype. Conclusions: HNF4α maintains hepatocyte identity by regulating miR-29a and -29b expression, which in turn control epigenetic modifications by limiting DNMT3A and DNMT3B levels

A chemical signature from fast-rotating low-metallicity massive stars: ROA 276 in ω Centauri

© 2017. The American Astronomical Society. All rights reserved. We present a chemical abundance analysis of a metal-poor star, ROA 276, in the stellar system ω Centauri. We confirm that this star has an unusually high [Sr/Ba] abundance ratio. Additionally, ROA 276 exhibits remarkably high abundance ratios, [X/Fe] , for all elements from Cu to Mo along with normal abundance ratios for the elements from Ba to Pb. The chemical abundance pattern of ROA 276, relative to a primordial ω Cen star ROA 46, is best fit by a fast-rotating low-metallicity massive stellar model of 20 , [Fe/H] = -1.8, and an initial rotation 0.4 times the critical value; no other nucleosynthetic source can match the neutron-capture element distribution. ROA 276 arguably offers the most definitive proof to date that fast-rotating massive stars contributed to the production of heavy elements in the early universe

Animal models of tic disorders: A translational perspective

Tics are repetitive, sudden movements and/or vocalizations, typically enacted as maladaptive responses to intrusive premonitory urges. The most severe tic disorder, Tourette syndrome (TS), is a childhood-onset condition featuring multiple motor and at least one phonic tic for a duration longer than 1 year. The pharmacological treatment of TS is mainly based on antipsychotic agents; while these drugs are often effective in reducing tic severity and frequency, their therapeutic compliance is limited by serious motor and cognitive side effects. The identification of novel therapeutic targets and development of better treatments for tic disorders is conditional on the development of animal models with high translational validity. In addition, these experimental tools can prove extremely useful to test hypotheses on the etiology and neurobiological bases of TS and related conditions. In recent years, the translational value of these animal models has been enhanced, thanks to a significant re-organization of our conceptual framework of neuropsychiatric disorders, with a greater focus on endophenotypes and quantitative indices, rather than qualitative descriptors. Given the complex and multifactorial nature of TS and other tic disorders, the selection of animal models that can appropriately capture specific symptomatic aspects of these conditions can pose significant theoretical and methodological challenges. In this article, we will review the state of the art on the available animal models of tic disorders, based on genetic mutations, environmental interventions as well as pharmacological manipulations. Furthermore, we will outline emerging lines of translational research showing how some of these experimental preparations have led to significant progress in the identification of novel therapeutic targets for tic disorders

Identification and characterization of archaeal and bacterial F420-dependent thioredoxin reductases

The thioredoxin pathway is an antioxidant system present in most organisms. Electrons flow from a thioredoxin reductase to thioredoxin at the expense of a specific electron donor. Most known thioredoxin reductases rely on NADPH as reducing cofactor. Yet, in 2016 a new type of thioredoxin reductase was discovered in archaea which utilizes instead a reduced deazaflavin cofactor (F 420 H 2 ). For this reason, the respective enzyme was named deazaflavin-dependent flavin-containing thioredoxin reductase (DFTR). To have a broader understanding of the biochemistry of DFTRs, we identified and characterized two other archaeal representatives. A detailed kinetic study, which included pre-steady state kinetic analyses, revealed these two DFTRs are highly specific for F 420 H 2 while displaying marginal activity with NADPH. Nevertheless, they share mechanistic features with the canonical thioredoxin reductases that dependent on NADPH (NTRs). A detailed structural analysis led the identification of two key residues that tune cofactor specificity of DFTRs. This allowed us to propose a DFTR-specific sequence motif that enabled for the first time the identification and experimental characterization of a bacterial DFTR. </p

Cardiovascular disease risk in the offspring of diabetic women: the impact of the intrauterine environment

The incidence of gestational diabetes is increasing worldwide, exposing large numbers of infants to hyperglycaemia whilst in utero. This exposure may have a long-term negative impact on the cardiovascular health of the offspring. Novel methods to assess cardiovascular status in the neonatal period are now available&mdash;including measuring arterial intima-media thickness and retinal photography. These measures will allow researchers to assess the relative impact of intrauterine exposures, distinguishing these from genetic or postnatal environmental factors. Understanding the long-term impact of the intrauterine environment should allow the development of more effective health policy and interventions to decrease the future burden of cardiovascular disease. Initiating disease prevention aimed at the developing fetus during the antenatal period may optimise community health outcomes

Novel multitarget inhibitors with antiangiogenic and immunomodulator properties

By means of docking studies, seventeen compounds T.1-T17 have been designed and evaluated as multitarget inhibitors of VEGFR-2 and PD-L1 proteins in order to overcome resistance phenomena offered by cancer. All these designed molecules display a urea moiety as a common structural feature and eight of them (T.1-T8) further contain a 1,2,3-triazol moiety. The antiproliferative activity of these molecules on several tumor cell lines (HT-29, MCF-7, HeLa, A549, HL-60), on the endothelial cell line HMEC-1 and on the non-tumor cell line HEK-293 has been determined. The urea derivatives were also evaluated for their antiangiogenic properties, whereby their ability to inhibit tubulogenesis and kinase activity employing flow cytometry, ELISA, immunofluorescence and western blot techniques was measured. In addition, these techniques were also employed to investigate the immunomodulator action of the synthetic compounds on the inhibition of PD-L1 and c-Myc proteins. Compound T.2, 1-(3-chlorophenyl)-3-(2-(4-(4-methoxybenzyl)-1H-1,2,3-triazol-1-yl)ethyl)urea, has shown similar results to sorafenib in both down-regulation of VEGFR-2 and inhibition of the kinase activity of this receptor. Furthermore, compound T.14, (E)-1-(4-chlorophenyl)-3-(3-(4-methoxystyryl)phenyl)urea, improves the effect of T.2 as regards tube formation of endothelial cells and inhibition of VEGFR-2 tyrosine kinase activity. In addition, T.14 improves the effect of the experimental drug BMS-8 in the inhibition of PD-L1 and c-Myc proteins

The remarkable influence of N , O -ligands in the assembly of a bis-calix[4]arene-supported [MnIV2MnIII10MnII8] cluster

Calix[4]arenes are versatile ligands, capable of supporting the formation of a wide variety of polymetallic clusters comprising 3d, 4f or 3d-4f metal ions. Calixarene-based metal ion fragments act as both bridging and structure capping moieties in these systems, and this behaviour is systematically extended upon moving to bis-calix[4]arene, a relatively new ligand in which two calix[4]arenes are tethered at the methylene bridge position. N,O-Ligands greatly influence cluster formation with bis-calix[4]arene, affording a remarkable mixed-valence [MnIV2MnIII10MnII8] cluster that displays coordination chemistry typical of each ligand type, but also new structure capping behaviour for the latter.</p

Transcriptional Regulation of Genes Involved in Zinc Uptake, Sequestration and Redistribution Following Foliar Zinc Application to Medicago sativa

Zinc (Zn) is an essential micronutrient for plants and animals, and Zn deficiency is a widespread problem for agricultural production. Although many studies have been performed on biofortification of staple crops with Zn, few studies have focused on forages. Here, the molecular mechanisms of Zn transport in alfalfa (Medicago sativa L.) were investigated following foliar Zn applications. Zinc uptake and redistribution between shoot and root were determined following application of six Zn doses to leaves. Twelve putative genes encoding proteins involved in Zn transport (MsZIP1-7, MsZIF1, MsMTP1, MsYSL1, MsHMA4, and MsNAS1) were identified and changes in their expression following Zn application were quantified using newly designed RT-qPCR assays. These assays are the first designed specifically for alfalfa and resulted in being more efficient than the ones already available for Medicago truncatula (i.e., MtZIP1-7 and MtMTP1). Shoot and root Zn concentration was increased following foliar Zn applications 0.1 mg plant1. Increased expression of MsZIP2, MsHMA4, and MsNAS1 in shoots, and of MsZIP2 and MsHMA4 in roots was observed with the largest Zn dose (10 mg Zn plant1). By contrast, MsZIP3 was downregulated in shoots at Zn doses 0.1 mg plant1. Three functional gene modules, involved in Zn uptake by cells, vacuolar Zn sequestration, and Zn redistribution within the plant, were identified. These results will inform genetic engineering strategies aimed at increasing the efficiency of crop Zn biofortification

Canakinumab treatment for patients with active recurrent or chronic TNF receptor-associated periodic syndrome (TRAPS): An open-label, phase II study

OBJECTIVE: To evaluate the efficacy of canakinumab, a high-affinity human monoclonal anti-interleukin-1β antibody, in inducing complete or almost complete responses in patients with active tumour necrosis factor receptor-associated periodic syndrome (TRAPS). METHODS: Twenty patients (aged 7-78 years) with active recurrent or chronic TRAPS were treated with canakinumab 150 mg every 4 weeks for 4 months (2 mg/kg for those ≤40 kg) in this open-label, proof-of-concept, phase II study. Canakinumab was then withdrawn for up to 5 months, with reintroduction on relapse, and 4 weekly administration (subsequently increased to every 8 weeks) for 24 months. The primary efficacy variable was the proportion of patients achieving complete or almost complete response at day 15, defined as clinical remission (Physician's Global Assessment score ≤1) and full or partial serological remission. RESULTS: Nineteen patients (19/20, 95%; 95% CI 75.1% to 99.9%) achieved the primary efficacy variable. Responses to canakinumab occurred rapidly; median time to clinical remission 4 days (95% CI 3 to 8 days). All patients relapsed after canakinumab was withdrawn; median time to relapse 91.5 days (95% CI 65 to 117 days). On reintroduction of canakinumab, clinical and serological responses were similar to those seen during the first phase, and were sustained throughout treatment. Canakinumab was well tolerated and clinical responses were accompanied by rapid and sustained improvement in health-related quality of life. Weight normalised pharmacokinetics of canakinumab, although limited, appeared to be consistent with historical canakinumab data. CONCLUSIONS: Canakinumab induces rapid disease control in patients with active TRAPS, and clinical benefits are sustained during long-term treatment

Synthesis and biological evaluation of carbamates derived from aminocombretastatin A-4 as vascular disrupting agents

A series of t wenty-six carbamates derived from aminocombretastatin A- 4 (AmCA-4 ) were syn thesized and evaluated for their capacity to affect cell proliferation, tubulin polymerization, mitotic cell arrest, microtubule network organization, apoptos is and endothelial tubular structures in vitro. The anti- pro liferative activity of the synthetic carbamates was measured on several human tumor cell lines (i.e. HT-29, MCF-7, HeLa, A-549, MDA-MB-231, H L-60) as well as on the endothelial cell line HMEC-1 and the non-tumor cell line H EK-293. The compounds showed anti-proliferative activity in the nanomolar range thereby exceeding by far the activity of combretastatin A-4 (CA-4 ) and, in some cases, the activity of AmCA-4. The most active compounds proved to be the carbamates bearing chloro, bromo or methoxy groups in the meta position of the phenyl ring. Moreover, all carbamates inhibited in vitro tubulin polymerization, in a similar manne r to that of CA-4 and Am CA-4 by interacting with the colchicine binding site in tubulin. The synthetic carbamates proved as active as AmCA-4 in causing mitotic arrest, as asses sed in A549 human lung cancer cells, and disruption of the microtubule ce llular network. Some selected carbamates induced apoptosis at concentrations as low as 10 nM, being more active than AmCA-4. Final ly, these selected carbamates displayed a vascular disrupting activity on endothelial cells in a dose-dependent manner. In conclusion, our data indicate that carbamates derived from aminocombretastatin A-4 represent interesting lead compounds for the design of vascular dis- rupting agent