Inhibition of Akt signaling in hepatoma cells induces apoptotic cell death independent of Akt activation status

Cataloged from PDF version of article.The serine/threonine kinase Akt, a downstream effector of phosphatidylinositol 3-kinase (PI3K), is involved in cell survival and anti-apoptotic signaling. Akt has been shown to be constitutively expressed in a variety of human tumors including hepatocellular carcinoma (HCC). In this report we analyzed the status of Akt pathway in three HCC cell lines, and tested cytotoxic effects of Akt pathway inhibitors LY294002, Wortmannin and Inhibitor VIII. In Mahlavu human hepatoma cells Akt was constitutively activated, as demonstrated by its Ser473 phosphorylation, downstream hyperphosphorylation of BAD on Ser136, and by a specific cell-free kinase assay. In contrast, Huh7 and HepG2 did not show hyperactivation when tested by the same criteria. Akt enzyme hyperactivation in Mahlavu was associated with a loss of PTEN protein expression. Akt signaling was inhibited by the upstream kinase inhibitors, LY294002, Wortmannin, as well as by the specific Akt Inhibitor VIII in all three hepatoma cell lines. Cytotoxicity assays with Akt inhibitors in the same cell lines indicated that they were all sensitive, but with different IC50 values as assayed by RT-CES. We also demonstrated that the cytotoxic effect was through apoptotic cell death. Our findings provide evidence for its constitutive activation in one HCC cell line, and that HCC cell lines, independent of their Akt activation status respond to Akt inhibitors by apoptotic cell death. Thus, Akt inhibition may be considered as an attractive therapeutic intervention in liver cancer. © Springer Science+Business Media, LLC 2010

Antibody mediated neutralization of myelin associated EphrinB3 accelerates CNS remyelination

This is the final version of the article. It was first available from Springer via http://dx.doi.org/10.1007/s00401-015-1521-1Remyelination in multiple sclerosis (MS) lesions often remains incomplete despite the presence of oligodendrocyte progenitor cells (OPCs). Amongst other factors, successful remyelination depends on the phagocytic clearance of myelin debris. However, the proteins in myelin debris that act as potent and selective inhibitors on OPC differentiation and inhibit CNS remyelination remain unknown. Here, we identify the transmembrane signalling protein EphrinB3 as important mediator of this inhibition, using a protein analytical approach in combination with a primary rodent OPC assay. In the presence of EphrinB3, OPCs fail to differentiate. In a rat model of remyelination, infusion of EphrinB3 inhibits remyelination. In contrast, masking EphrinB3 epitopes using antibodies promotes remyelination. Finally, we identify EphrinB3 in MS lesions and demonstrate that MS lesion extracts inhibit OPC differentiation while antibody-mediated masking of EphrinB3 epitopes promotes it. Our findings suggest that EphrinB3 could be a target for therapies aiming at promoting remyelination in demyelinating disease.This work was supported by the UK MS Society Grant ref: 941/11. MRNK held a NIHR Clinical Lectureship. KAN was supported by an ERC advanced award

Screening and selection of novel animal probiotics isolated from bovine chyme

Probiotics, gut-colonizing microorganisms capable of conferring a number of health benefits to their hosts, are highly desirable as animal feed supplements. Members of the Gram-positive genus Bacillus are often utilized as probiotics, since endospores formed by those bacteria render them highly resistant to environmental extremes and therefore capable of surviving gastrointestinal tract conditions. In this study, 84 distinct bacterial colonies were obtained from bovine chyme and 29 isolates were determined as Bacillus species. These isolates were principally screened for their antimicrobial activity against a group of two Gram-positive and fourGram-negative bacteria, including known human and animal pathogens such as Salmonella enterica, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus. Seven strains displaying strong antimicrobial activity against the test cohort were further evaluated for other properties desirable from animal probiotics, including high spore-forming capacity and adhesiveness, resistance to pH extremes and ability to form biofilms. The isolates were found to resist simulated gastrointestinal conditions and most of the antibiotics tested. In addition, plasmid presence was checked and cytotoxicity tests were performed to evaluate the potential risks of antibiotic resistance transfer and unintended pathogenic effects on host, respectively. We propose that the bacterial isolates are suitable for use as animal probiotics. © Springer-Verlag Berlin Heidelberg and the University of Milan 2012

Antimicrobial efficacy of low concentration PVP-silver nanoparticles deposited on DBD plasma-treated polyamide 6,6 fabric

In this study, a low concentration (10 μg·mL−1) of poly(N-vinylpyrrolidone) (PVP)-coated silver nanoparticles (AgNPs) were deposited by spray and exhaustion (30, 70 and 100 ◦C) methods onto untreated and dielectric barrier discharge (DBD) plasma-treated polyamide 6,6 (PA66) fabric. DBD plasma-treated samples showed higher AgNP deposition than untreated ones for all methods. After five washing cycles, only DBD plasma-treated samples displayed AgNPs on the fabric surface. The best-performing method was exhaustion at 30 ◦C, which exhibited less agglomeration and the best antibacterial efficacy against S. aureus (4 log reduction). For E. coli, the antimicrobial effect showed good results in all the exhaustion samples (5 log reduction). Considering the spray method, only the DBD plasma-treated samples showed some bacteriostatic activity for both strains, but the AgNP concentration was not enough to have a bactericidal effect. Our results suggest DBD plasma may be a low cost and chemical-free method for the preparation of antibacterial textiles, allowing for the immobilization of a very low—but effective—concentration of AgNPs.This work was funded by European Regional Development funds (FEDER) through the Competitiveness and Internationalization Operational Program (POCI) – COMPETE and by National Funds through Fundação para a Ciência e Tecnologia (FCT)—under the project POCI-01-0145-FEDER-007136 and UID/CTM/00264/2019. Isabel Ribeiro (SFRH/BD/137668/2018) acknowledges FCT, Portugal, for its doctoral grant financial support. A. Zille also acknowledges financial support of the FCT through an Investigator FCT Research contract (IF/00071/2015) and the project PTDC/CTM-TEX/28295/2017 financed by FCT, FEDER and POCI in the frame of the Portugal 2020 program

Design of a Gd-DOTA-Phthalocyanine Conjugate Combining MRI Contrast Imaging and Photosensitization Properties as a Potential Molecular Theranostic

Cataloged from PDF version of article.The design and synthesis of a phthalocyanine - Gd-DOTA conjugate is presented to open the way to novel molecular theranostics, combining the properties of MRI contrast imaging with photodynamic therapy. The rational design of the conjugate integrates isomeric purity of the phthalocyanine core substitution, suitable biocompatibility with the use of polyoxo water-solubilizing substituents, and a convergent synthetic strategy ended by the use of click chemistry to graft the Gd-DOTA moiety to the phthalocyanine. Photophysical and photochemical properties, contrast imaging experiments and preliminary in vitro investigations proved that such a combination is relevant and lead to a new type of potential theranostic agent

EMAS position statement : Predictors of premature and early natural menopause

Introduction: While the associations of genetic, reproductive and environmental factors with the timing of natural menopause have been extensively investigated, few epidemiological studies have specifically examined their association with premature (<40 years) or early natural menopause (40-45 years). Aim: The aim of this position statement is to provide evidence on the predictors of premature and early natural menopause, as well as recommendations for the management of premature and early menopause and future research. Materials and methods: Literature review and consensus of expert opinion. Results and conclusions: Strong genetic predictors of premature and early menopause include a family history of premature or early menopause, being a child of a multiple pregnancy and some specific genetic variants. Women with early menarche and nulliparity or low parity are also at a higher risk of experiencing premature or early menopause. Cigarette smoking (with a strong dose-response effect) and being underweight have been consistently associated with premature and early menopause. Current guidelines for the management of premature and early menopause mainly focus on early initiation of hormone therapy (HT) and continued treatment until the woman reaches the average age at menopause (50-52 years). We suggest that clinicians and health professionals consider the age at menopause of the relevant region or ethnic group as part of the assessment for the timing of HT cessation. In addition, there should be early monitoring of women with a family history of early menopause, who are a child of a multiple pregnancy, or who have had early menarche (especially those who have had no children). As part of preventive health strategies, women should be encouraged to quit smoking (preferably before the age of 30 years) and maintain optimal weight in order to reduce their risk of premature or early menopause.Peer reviewe