134 research outputs found

    Clathrin-dependent endocytosis of membrane-bound RANKL in differentiated osteoclasts

    Get PDF
    Bone is continuously repaired and remodelled through well-coordinated activity of osteoblasts that form new bone and osteoclasts, which resorb it. Osteoblasts synthesize and secrete two key molecules that are important for osteoclast differentiation, namely the ligand for the receptor of activator of nuclear factor κB (RANKL) and its decoy receptor osteoprotegerin (OPG). Active membrane transport is a typical feature of the resorbing osteoclast during bone resorption. Normally, one resorption cycle takes several hours as observed by monitoring actin ring formation and consequent disappearance in vitro. During these cyclic changes, the cytoskeleton undergoes remarkable dynamic rearrangement. Active cells show a continuous process of exocytosis that plays an essential role in transport of membrane components, soluble molecules and receptor-mediated ligands thus allowing them to communicate with the environment. The processes that govern intracellular transport and trafficking in mature osteoclasts are poorly known. The principal methodological problem that have made these studies difficult is a physiological culture of osteoclasts that permit observing the vesicle apparatus in conditions similar to the in vivo conditions. In the present study we have used a number of morphological approaches to characterize the composition, formation and the endocytic and biosynthetic pathways that play roles in dynamics of differentiation of mature bone resorbing cells using a tri-dimensional system of physiologic coculture

    Involvement of the phosphoinositide 3-kinase/Akt signaling pathway in the resistance to therapeutic treatments of human leukemias.

    Get PDF

    AMP-dependent kinase/mammalian target of rapamycin complex 1 signaling in T-cell acute lymphoblastic leukemia: therapeutic implications.

    Get PDF
    The mammalian target of rapamycin (mTOR) serine/threonine kinase is the catalytic subunit of two multi-protein complexes, referred to as mTORC1 and mTORC2. Signaling downstream of mTORC1 has a critical role in leukemic cell biology by controlling mRNA translation of genes involved in both cell survival and proliferation. mTORC1 activity can be downmodulated by upregulating the liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) pathway. Here, we have explored the therapeutic potential of the anti-diabetic drug, metformin (an LKB1/AMPK activator), against both T-cell acute lymphoblastic leukemia (T-ALL) cell lines and primary samples from T-ALL patients displaying mTORC1 activation. Metformin affected T-ALL cell viability by inducing autophagy and apoptosis. However, it was much less toxic against proliferating CD4þ T-lymphocytes from healthy donors. Western blot analysis demonstrated dephosphorylation of mTORC1 downstream targets. Unlike rapamycin, we found a marked inhibition of mRNA translation in T-ALL cells treated with metformin. Remarkably, metformin targeted the side population of T-ALL cell lines as well as a putative leukemia-initiating cell subpopulation (CD34þ/CD7/CD4) in patient samples. In conclusion, metformin displayed a remarkable anti-leukemic activity, which emphasizes future development of LKB1/AMPK activators as clinical candidates for therapy in T-ALL. Leukemia (2012) 26, 91–100; doi:10.1038/leu.2011.269; published online 4 October 201

    miR-26b Promotes Granulosa Cell Apoptosis by Targeting ATM during Follicular Atresia in Porcine Ovary

    Get PDF
    More than 99% of ovarian follicles undergo atresia in mammals, but the mechanism of follicular atresia remains to be elucidated. In this study, we explored microRNA (miRNA) regulation of follicular atresia in porcine ovary. A miRNA expression profile was constructed for healthy, early atretic, and progressively atretic follicles, and the differentially expressed miRNAs were selected and analyzed. We found that miR-26b, which was upregulated during follicular atresia, increased the number of DNA breaks and promoted granulosa cell apoptosis by targeting the ataxia telangiectasia mutated gene directly in vitro

    Analisi dei tempi d\u2019attesa tra le varie fasi di gestione dei carcinomi mammari screening-detected a Trieste nel biennio 2013-2014: come si pu\uf2 migliorare?

    Get PDF
    Gli indicatori relativi ai tempi di attesa sono difficili da rispettare, come recentemente evidenziato al XIII Convegno ONS 2015 . Per questo motivo \ue8 fondamentale identificare in quale momento della gestione dei carcinomi screening-detected si concentrino i ritardi e stabilirne le cause (se attribuibili alla paziente o all\u2019organizzazione del programma o intrinseci al tipo di lesione) cos\uec da proporre mirate modifiche migliorative. Metodi: L\u2019analisi riguarda 146 carcinomi screening-detected consecutivi (biennio 2013-2014). Sono stati misurati i tempi tra le varie fasi diagnostiche (Mammografia di I\ub0 livello, Richiamo II\ub0 livello, I\ub0 approfondimento cito/microistologico, Comunicazione diagnosi) e i tempi chirurgici (Visita chirurgica, Intervento chirurgico, Referto istologico con marcatori biologici, Visita oncologica). Per ogni fase sono stati calcolati i tempi medi/mediani rappresentati tramite box plot e giustificati gli outliers.Risultati: La latenza nella presa in carico chirurgica \ue8 legato alla complessit\ue0 degli esami preoperatori (3) (tempo mediano tra richiamo al II\ub0 livello ed intervento: 53 giorni (se unico esame pre-operatorio) vs 73 (se pi\uf9 di un esame pre-operatorio, p<0.0001), mentre rispetto ad un recente studio (4) il tempo mediano tra visita chirurgica e intervento non \ue8 aumentato per i casi con necessit\ue0 di RM (28 vs 26 giorni, p=0.13), perch\ue9 gi\ue0 programmata in fase preoperatoria. Per i casi con mastectomia sempre con ricostruzione, si registra un tempo medio dalla visita chirurgica all\u2019intervento di 7 giorni superiore rispetto alle quadrantectomie. Ulteriore criticit\ue0 \ue8 il tempo mediano tra intervento e visita oncologica (44 giorni), attribuibile in parte ad un \u201critardo\u201d nella disponibilit\ue0 dei marcatori biomolecolari (soprattutto HER2/FISH) ed in parte a rinvii dell\u2019appuntamento da parte della paziente stessa Conclusioni: Soltanto un attento monitoraggio del turnaround time dell\u2019intero percorso delle pazienti con carcinoma screening detected consente l\u2019identificazione dei punti di debolezza su cui intervenire efficacemente per garantire il rispetto degli indicatori

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

    Get PDF
    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
    corecore