41 research outputs found

    The energy sensor AMPK regulates Hedgehog signaling in human cells through a unique Gli1 metabolic checkpoint

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    Hedgehog signaling controls proliferation of cerebellar granule cell precursors (GCPs) and its aberrant activation is a leading cause of Medulloblastoma, the most frequent pediatric brain tumor. We show here that the energy sensor AMPK inhibits Hh signaling by phosphorylating a single residue of human Gli1 that is not conserved in other species.Studies with selective agonists and genetic deletion have revealed that AMPK activation inhibits canonical Hh signaling in human, but not in mouse cells. Indeed we show that AMPK phosphorylates Gli1 at the unique residue Ser408, which is conserved only in primates but not in other species. Once phosphorylated, Gli1 is targeted for proteasomal degradation. Notably, we show that selective AMPK activation inhibits Gli1-driven proliferation and that this effect is linked to Ser408 phosphorylation, which represents a key metabolic checkpoint for Hh signaling.Collectively, this data unveil a novel mechanism of inhibition of Gli1 function, which is exclusive for human cells and may be exploited for the treatment of Medulloblastoma or other Gli1 driven tumors

    Discontinuously supervised aerobic training vs. physical activity promotion in the self-management of type 2 diabetes in older Italian patients: design and methods of the 'TRIPL-A' randomized controlled trial

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    Physical activity (PA) has health benefits for people with type 2 diabetes (T2D). Indeed, regular PA is considered an important part of any T2D management plan, yet most patients adopt a sedentary lifestyle. Exercise referral schemes (ERS) have the potential to effectively promote physical activity among T2D patients, and their effectiveness may be enhanced when they are supported by computer-based technologies. The 'TRIPL-A' study (i.e., a TRIal to promote PhysicaL Activity among patients in the young-old age affected by T2D) aims to assess if realizing an innovative ERS, based on a strong partnership among general practitioners, specialist physicians, exercise specialists, and patients, and supported by a web-based application (WBA), can effectively lead sedentary older T2D patients to adopt an active lifestyle

    β-arrestin1-mediated acetylation of Gli1 regulates Hedgehog/Gli signaling and modulates self-renewal of SHH medulloblastoma cancer stem cells

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    Background Aberrant Sonic Hedgehog/Gli (Hh/Gli) signaling pathway is a critical regulator of Sonic hedgehog medulloblastoma (SHH-MB). Cancer stem cells (CSCs), thought to be largely responsible for tumor initiation, maintenance, dissemination and relapse, have been identified in SHH-MB. Since we previously demonstrated that Hh/Gli signaling controls CSCs features in SHH-MB and that in these tumors miR-326 is down regulated, here we investigated whether there is a functional link between Hh/Gli signaling and miR-326. Methods We evaluated β-arrestin1 (Arrb1) and its intragenic miR-326 levels in CSCs derived from SHH-MB. Subsequently, we modulated the expression of Arrb1 and miR-326 in CSCs in order to gain insight into their biological role. We also analyzed the mechanism by which Arrb1 and miR-326 control Hh/Gli signaling and self-renewal, using luciferase and protein immunoprecipitation assays. Results Low levels of Arrb1 and miR-326 represent a feature of CSCs derived from SHH-MB. We observed that re-expression of Arrb1 and miR-326 inhibits Hh/Gli signaling pathway at multiple levels, which cause impaired proliferation and self-renewal, accompanied by down regulation of Nanog levels. In detail, miR-326 negatively regulates two components of the Hh/Gli pathway the receptor Smoothened (Smo) and the transcription factor Gli2, whereas Arrb1 suppresses the transcriptional activity of Gli1, by potentiating its p300-mediated acetylation. Conclusions Our results identify a new molecular mechanism involving miR-326 and Arrb1 as regulators of SHH-MB CSCs. Specifically, low levels of Arrb1 and miR-326 trigger and maintain Hh/Gli signaling and self-renewal

    Catching allergy by a simple questionnaire

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    Background: Identifying allergic rhinitis requires allergy testing, but the first-line referral for rhinitis are usually primary care physicians (PCP), who are not familiar with such tests. The availability of easy and simple tests to be used by PCP to suggest allergy should be very useful. Methods: The Respiratory Allergy Prediction (RAP) test, based on 9 questions and previously validated by a panel of experts, was evaluated in this study. Results: An overall number of 401 patients (48.6% males, age range 14-62 years) with respiratory symptoms was included. Of them, 89 (22.2%) showed negative results to SPT, while 312 (77.8%) had at least one positive result to SPT. Cohen's kappa coefficient showed that all questions had an almost perfect excellent agreement between pre and post-test. The algorithm of decision-tree growth Chi-squared Automatic Interaction Detector showed that answering yes to the question 4 (Your nasal/ocular complains do usually start or worsen during the spring?), 6 (Did you ever had cough or shortness of breath, even during exercise?) and 8 (Do you use nasal sprays frequently?) gave a probability to have a positive SPT of 85%. Conclusions: These findings show that RAP test can be proposed as an useful tool to be used by physician other than allergists when evaluating patients with rhinitis, suggesting the need of allergy testing

    Gli1/DNA interaction is a druggable target for Hedgehog-dependent tumors

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    Hedgehog signaling is essential for tissue development and stemness, and its deregulation has been observed in many tumors. Aberrant activation of Hedgehog signaling is the result of genetic mutations of pathway components or other Smo-dependent or independent mechanisms, all triggering the downstream effector Gli1. For this reason, understanding the poorly elucidated mechanism of Gli1-mediated transcription allows to identify novel molecules blocking the pathway at a downstream level, representing a critical goal in tumor biology. Here, we clarify the structural requirements of the pathway effector Gli1 for binding to DNA and identify Glabrescione B as the first small molecule binding to Gli1 zinc finger and impairing Gli1 activity by interfering with its interaction with DNA. Remarkably, as a consequence of its robust inhibitory effect on Gli1 activity, Glabrescione B inhibited the growth of Hedgehog-dependent tumor cells in vitro and in vivo as well as the self-renewal ability and clonogenicity of tumor-derived stem cells. The identification of the structural requirements of Gli1/DNA interaction highlights their relevance for pharmacologic interference of Gli signaling

    European Atlas of Natural Radiation

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    Natural ionizing radiation is considered as the largest contributor to the collective effective dose received by the world population. The human population is continuously exposed to ionizing radiation from several natural sources that can be classified into two broad categories: high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and radioactive nuclides generated during the formation of the Earth and still present in the Earth’s crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium and thorium radioactive families together with potassium. In most circumstances, radon, a noble gas produced in the radioactive decay of uranium, is the most important contributor to the total dose. This Atlas aims to present the current state of knowledge of natural radioactivity, by giving general background information, and describing its various sources. This reference material is complemented by a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources. It is a compilation of contributions and reviews received from more than 80 experts in their field: they come from universities, research centres, national and European authorities and international organizations. This Atlas provides reference material and makes harmonized datasets available to the scientific community and national competent authorities. In parallel, this Atlas may serve as a tool for the public to: • familiarize itself with natural radioactivity; • be informed about the levels of natural radioactivity caused by different sources; • have a more balanced view of the annual dose received by the world population, to which natural radioactivity is the largest contributor; • and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence to better understand the latter.JRC.G.10-Knowledge for Nuclear Security and Safet

    European Atlas of Natural Radiation

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    Natural ionizing radiation is considered as the largest contributor to the collective effective dose received by the world population. The human population is continuously exposed to ionizing radiation from several natural sources that can be classified into two broad categories: high-energy cosmic rays incident on the Earth’s atmosphere and releasing secondary radiation (cosmic contribution); and radioactive nuclides generated during the formation of the Earth and still present in the Earth’s crust (terrestrial contribution). Terrestrial radioactivity is mostly produced by the uranium and thorium radioactive families together with potassium. In most circumstances, radon, a noble gas produced in the radioactive decay of uranium, is the most important contributor to the total dose.This Atlas aims to present the current state of knowledge of natural radioactivity, by giving general background information, and describing its various sources. This reference material is complemented by a collection of maps of Europe displaying the levels of natural radioactivity caused by different sources. It is a compilation of contributions and reviews received from more than 80 experts in their field: they come from universities, research centres, national and European authorities and international organizations.This Atlas provides reference material and makes harmonized datasets available to the scientific community and national competent authorities. In parallel, this Atlas may serve as a tool for the public to: • familiarize itself with natural radioactivity;• be informed about the levels of natural radioactivity caused by different sources;• have a more balanced view of the annual dose received by the world population, to which natural radioactivity is the largest contributor;• and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence to better understand the latter.Additional information at: https://remon.jrc.ec.europa.eu/About/Atlas-of-Natural-Radiatio

    Georadar investigations and monitoring of the wall structures and vault system of the Sala delle Asse, in Leonardo da Vinci - The Sala delle Asse of the Sforza Castle

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    In 2011, the engineer Giuseppe Albano studied the geometry and state of conservation of the structures of the vault system of the Sala delle Asse to assess any damage and instabilities in the room and proposed a series of studies and monitoring for the cracks that had been detected on the extrados of the lower vault and on the vertical structures, with the aim of identifying any movement that might be un­der way. Currently, a diagnostic campaign is in progress, targeted towards understanding the build­ ing technique and structural behaviour of the vault system. Radar studies were conducted to reconstruct the stratigraphy of the system comprising the lunetted cloister vault, the depressed arch cloister vault above and the floor of the room on the upper floor. Other radar studies were conducted to characterize the raised wall structures, which are of notable thickness (even as much as aver 2.5 m) and to identify cavities and a flue that runs along the full height of the north-east wall. A topographical/diagnostic laser scanner survey will make it possible to reveal the critical points of the structures and types of instability and provide understanding of the dynamics of the crack pattern. The stratigraphic reading will make it possible to codify the archaeological sequence of the built structure, the deterioration and state of damage (the contribution The Diagnostic Survey: The Sala delle Asse and its Context in the present volume).The need to speed Up the time spent collecting information that would be useful for safeguarding and protecting the room forced the immediate installation of a system far monitoring cracks based on the information available at the time, which derived from a preliminary survey and the results of thermographic studies (see the contribution The Preliminary Thermo-Hygrometric Research and Environmental Monitoring of the Sala delle Asse in this volume), which revealed a few structural cracks. It will be possible to review or integrate the arrangement of the transducers based on the results of the above-described survey
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