82 research outputs found

    Role of p38 MAPK and RNA-dependent protein kinase (PKR) in hepatitis C virus core-dependent nuclear delocalization of cyclin B1.

    Get PDF
    Some hepatitis C virus (HCV) proteins, including core protein, deregulate the cell cycle of infected cells, thereby playing an important role in the viral pathogenesis of HCC. Thus far, there are only few studies that have deeply investigated in depth the effects of the HCV core protein expression on the progression through the G1/S and G2/M phases of the cell cycle. To shed light on the molecular mechanisms by which the HCV core protein modulates cell proliferation, we have examined its effects on cell cycle in hepatocarcinoma cells. We show here that HCV core protein perturbs progression through both the G1/S and the G2/M phases, by modulating the expression and the activity of several cell cycle regulatory proteins. In particular, our data provided evidence that core-dependent deregulation of the G1/S phase and its related cyclin-CDK complexes depends upon the ERK1/2 pathway. On the other hand, the viral protein also increases the activity of the cyclin B1-CDK1 complex via the p38 MAPK and JNK pathways. Moreover, we show that HCV core protein promotes nuclear import of cyclin B1, which is affected by the inhibition of both the p38 and the RNA-dependent protein kinase (PKR) activities. The important role of p38 MAPK in regulating G2/M phase transition has been previously documented. It is becoming clear that PKR has an important role in regulating both the G1/S and the G2/M phase, in which it induces M phase arrest. Based on our model, we now show, for the first time, that HCV core expression leads to deregulation of the mitotic checkpoint via a p38/PKR-dependent pathway

    p73 Is Regulated by Phosphorylation at the G2/M Transition *

    Get PDF
    p73 is a p53 paralog that encodes proapoptotic (transactivation-competent (TA)) and antiapoptotic (dominant negative) isoforms. TAp73 transcription factors mediate cell cycle arrest and/or apoptosis in response to DNA damage and are involved in developmental processes in the central nervous system and the immune system. p73 proteins may also play a role in the regulation of cell growth. Indeed, p73 expression is itself modulated during the cell cycle and TAp73 proteins accumulate in S phase cells. In addition, the function of p73 proteins is also regulated by post-translational modifications and protein-protein interactions in different cellular and pathophysiological contexts. Here we show that p73 is a physiological target of the p34cdc2-cyclin B mitotic kinase complex in vivo. Both p73beta and p73alpha isoforms are hyperphosphorylated in normal mitotic cells and during mitotic arrest induced by microtubule-targeting drugs. p34cdc2-cyclin B phosphorylates and associates with p73 in vivo, which results in a decreased ability of p73 to both bind DNA and activate transcription in mitotic cells. Indeed, p73 is excluded from condensed chromosomes in meta- and anaphase, redistributes throughout the mitotic cytoplasm, and unlike p53, shows no association with centrosomes. Together these results indicate that M phase-specific phosphorylation of p73 by p34cdc2-cyclin B is associated with negative regulation of its transcriptional activating function

    oleuropein overrides liver damage in steatotic mice

    Get PDF
    Abstract Nonalcoholic fatty liver disease (NAFLD) is a common disease in which oxidative stress plays a main role in causing organ damage. Oleuropein (Ole) is a phenolic compound with both significant anti-inflammatory and antioxidant properties. The aim of the present work has been focused on investigating the mechanisms by which Ole is able to improve liver damage, in the presence of hepatic steatosis. We evaluated the effects of Ole in female and male mice fed normal diet (ND) or high fat diet (HFD) for 8 weeks, adding or not Ole for the following 8 weeks. Ole induced a decrease in body, liver and heart weights and had an anti-inflammatory and antioxidant effects in HFD mice. Interestingly, in presence of the unhealthy diet, antioxidant effects of Ole overcome sex-related differences, improving liver damage

    Reactive oxygen intermediates mediate angiotensin II-induced c-Jun.c-Fos heterodimer DNA binding activity and proliferative hypertrophic responses in myogenic cells

    Get PDF
    Angiotensin II (Ang-II) receptor engagement activates many immediate early response genes in both vascular smooth muscle cells and cardiomyocytes whether a hyperplastic or hypertrophic response is taking place. Although the signaling pathways stimulated by Ang-II in different cell lines have been widely characterized, the correlation between the generation of different second messengers and specific physiological responses remains relatively unexplored. In this study, we report how in both C2C12 quiescent myoblasts and differentiated myotubes Ang-II significantly stimulates AP1-driven transcription and c-Jun.c-Fos heterodimer DNA binding activity. Using a set of different protein kinase inhibitors, we could demonstrate that Ang-II-induced increase in AP1 binding is not mediated by the cAMP-dependent pathway and that both protein kinase C and tyrosine kinases are involved. The observation that in quiescent myoblasts Ang-II increase of AP1 binding and induction of DNA synthesis and, in differentiated myotubes, Ang-II stimulation of protein synthesis are abolished by the cysteine-derivative and glutathione precursor N-acetyl-L-cysteine strongly suggests a role for reactive oxygen intermediates in the intracellular transduction of Ang-II signals for immediate early gene induction, cell proliferation, and hypertrophic responses

    Using social robot NAO for emotional support to children at a paediatric emergency department: a randomised clinical trial

    Get PDF
    Background: Social robots have been used for improving anxiety in children in stressful clinical situations, as during painful procedures. No studies have been performed yet to assess their effect in children while waiting for emergency room consultations. Objective: To assess the impact of social robots in managing stress in children waiting for an emergency room procedure through the assessment of salivary cortisol levels. Methods: This was an open randomised clinical trial in children attending a paediatric emergency department. Children accessing the emergency room were randomised to one of three groups: 1) playing with a NAO social robot; 2) playing with a study nurse; 3) waiting with parents. All children were measured salivary cortisol levels through a swab. Salivary cortisol levels before and after the intervention were compared in the three groups. We calculated the effect size of our interventions through the Cohen's d-based effect size correlation (r). Results: A total of 109 children aged 3 to 10 years were enrolled in the study and 94 had complete data for the analyses. Salivary cortisol levels decreased significantly more in the group exposed to robot interaction than in the other two groups (r=0.75). Cortisol levels decreased more in girls (r=0.92) than boys (r=0.57). Conclusions: Social robots are efficacious in decreasing stress in children accessing the emergency room and may be considered as a tool for improving emotional perceptions of children and their families in such a critical setting. Clinicaltrial: Robot Therapy in Pediatric Emergency, NCT04627909, https://clinicaltrials.gov/ct2/show/study/NCT04627909

    Application of machine learning approach in emergency department to support clinical decision making for SARS-CoV-2 infected patients

    Get PDF
    Abstract To support physicians in clinical decision process on patients affected by Coronavirus Disease 2019 (COVID-19) in areas with a low vaccination rate, we devised and evaluated the performances of several machine learning (ML) classifiers fed with readily available clinical and laboratory data. Our observational retrospective study collected data from a cohort of 779 COVID-19 patients presenting to three hospitals of the Lazio-Abruzzo area (Italy). Based on a different selection of clinical and respiratory (ROX index and PaO2/FiO2 ratio) variables, we devised an AI-driven tool to predict safe discharge from ED, disease severity and mortality during hospitalization. To predict safe discharge our best classifier is an RF integrated with ROX index that reached AUC of 0.96. To predict disease severity the best classifier was an RF integrated with ROX index that reached an AUC of 0.91. For mortality prediction the best classifier was an RF integrated with ROX index, that reached an AUC of 0.91. The results obtained thanks to our algorithms are consistent with the scientific literature an accomplish significant performances to forecast safe discharge from ED and severe clinical course of COVID-19

    Is copper a new target to counteract the progression of chronic diseases?

    No full text
    Altered regulation of copper (Cu) homeostasis may contribute to the development of many pathologies, such as metabolic, cardiovascular, neurodegenerative and cancerous diseases. Cu serum concentrations are strictly related to oxidative stress. During the past decade, it has been well demonstrated that even marginal deficits of this element contribute to development and progression of a number of chronic diseases. On the other hand, an excess of Cu may become a potent oxidant causing the generation of reactive oxygen species (ROS) and leading to the formation of macromolecules dangerous to health. In this review we will describe several chronic inflammatory diseases pathogenically related to the alteration of serum copper levels. Some considerations on present and future perspectives for use of natural antioxidants as effective drugs for the treatment of chronic diseases will be made to shed a glimmer of light on some of the mechanisms employed by natural antioxidants in controlling the distribution and concentration of biometals
    corecore