258 research outputs found

    Social Participation and Independent Mobility in Children: The Effects of Two Implementations of "We Go to School Alone"

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    The aim of this research was to determine the outcomes of the \u27\u27We go to school alone\u27\u27 program in two Districts of Rome through a longitudinal study involving 392 children (mean age?8.37 years) and 270 parents. The outcomes of the program in the two Districts were very different. Only one resulted in an increase in children\u27s autonomous mobility on the home-school journey, a reduction in the number of times a child was taken to school by car, and, even more important, in an increase in the general level of children\u27s independent mobility in their neighborhood. The findings are discussed in terms of a process evaluation that enabled us to understand the differing results

    High adenosine extracellular levels induce glioblastoma aggressive traits modulating the mesenchymal stromal cell secretome

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    Glioblastoma is an aggressive, fast-growing brain tumor influenced by the composition of the tumor microenvironment (TME) in which mesenchymal stromal cell (MSCs) play a pivotal role. Adenosine (ADO), a purinergic signal molecule, can reach up to high micromolar concentrations in TME. The activity of specific adenosine receptor subtypes on glioma cells has been widely explored, as have the effects of MSCs on tumor progression. However, the effects of high levels of ADO on glioma aggressive traits are still unclear as is its role in cancer cells-MSC cross-talk. Herein, we first studied the role of extracellular Adenosine (ADO) on isolated human U343MG cells as a glioblastoma cellular model, finding that at high concentrations it was able to prompt the gene expression of Snail and ZEB1, which regulate the epithelial–mesenchymal transition (EMT) process, even if a complete transition was not reached. These effects were mediated by the induction of ERK1/2 phosphorylation. Additionally, ADO affected isolated bone marrow derived MSCs (BM-MSCs) by modifying the pattern of secreted inflammatory cytokines. Then, the conditioned medium (CM) of BM-MSCs stimulated with ADO and a co-culture system were used to investigate the role of extracellular ADO in GBM–MSC cross-talk. The CM promoted the increase of glioma motility and induced a partial phenotypic change of glioblastoma cells. These effects were maintained when U343MG cells and BM-MSCs were co-cultured. In conclusion, ADO may affect glioma biology directly and through the modulation of the paracrine factors released by MSCs overall promoting a more aggressive phenotype. These results point out the importance to deeply investigate the role of extracellular soluble factors in the glioma cross-talk with other cell types of the TME to better understand its pathological mechanisms

    Memantine prodrug as a new agent for alzheimer’s disease

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    Hydrogen sulphide has recently drawn much attention due to its potent anti-inflammatory and neuroprotective roles in brain functions. The purpose of the current study was to exploit these beneficial properties of H 2 S to design a new agent for the treatment of Alzheimer’s disease (AD). To pursue our aims, we replaced the free amine group of memantine with an isothiocyanate functionality as a putative H 2 S-donor moiety. The new chemical entity, named memit, was then tested in vitro to determine whether it retains the pharmacological profile of the “native drug”, while also providing a source of H 2 S in the CNS. Indeed, Memit showed the ability to release H 2 S through a cysteine-mediated mechanism, thus generating memantine. Moreover, the new hybrid molecule exerts protective effects against neuronal inflammation and induces a drastic fall in ROS production. In addition, memit was also able to reduce the Aβ(1-42) self-induced aggregation and exerted cytoprotective effect against Aβ oligomers-induced damage in both human neurons and rat microglia cells. Finally, similarly to memantine, the new compound promotes autophagy, a complex process required for cellular homeostasis in cell survival that results to be altered in neurodegenerative diseases. In conclusion, our study revealed that memit is a prodrug of memantine. Further in vivo studies will be necessary to fully investigate the synergic or cumulative effects due to the H 2 S-releasing moiety and the native drug

    G PROTEIN-COUPLED RECEPTOR DESENSITISATION REGULATES STEM CELL DIFFERENTIATION

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    G-protein coupled receptors (GPCRs) play a key role in many complex biological processes, including regulation of stem cell pluripotency and differentiation. Signal transduction pathways that are activated during stem cell renewal and differentiation are shared, cross-activated or synergistic with GPCR stimulation [1]. Regulation of GPCR responses involved the activation of desensitization machinery, which started with phosphorylation of agonist-activated receptor by second messenger-dependent and/or GPCR kinases (GRKs)[1]. Besides controlling receptor responsiveness, GRKs can also act as agonist-regulated scaffolds assembling macromolecular signalosomes in the receptor environment, thereby contributing to signal propagation from cytosol to nucleus, and controlling gene transcription machinery [2]. Recent evidence suggests that the desensitization machinery fulfils a vital role in regulating cellular responses to GPCRs, and that changes in expression/functioning of these regulatory proteins may be crucial in the control of cell differentiation program [3]. These data are consistent with the notion that GPCR responsiveness may be differentially regulated during cell differentiation. In our hands, two different cellular models (oligodendrocyte precursor cells, OPCs, and mesenchymal stem cells, MSCs) were used to investigate the role of the GPCR desensitisation machinery in stem cell differentiation. During OPC differentiation, defective control of the membrane receptor GPR17 has been suggested to block cell maturation and impairs remyelination under demyelinating conditions [4]. Here we show, for the first time, a role for Murine double minute 2 (Mdm2), a ligase previously involved in ubiquitination/degradation of p53 protein. In maturing OPCs, the inhibition of Mdm2-p53 interactions increased GRK2 sequestration by Mdm2, leading to impaired GPR17 down-regulation and OPC maturation block. In MSCs, the A2B adenosine receptor (A2BAR) has been recently emerged as the major AR involved in osteoblastogenesis [5]. Proinflammatory cytokines, such as Tumour Necrosis Factor- (TNF-, have been demonstrated to regulate MSC differentiation and bone remodelling. Herein, we show that TNF- diminished GRK2 levels in MSCs, thus blocking A2BAR desensitization. As a result, TNF- enhanced the A2BAR-mediated responses and favoured MSC differentiation to osteoblasts in response to receptor agonists. The findings get new insights for discovering of the signals at the basis of cell differentiation

    Epigenetic Modifications of the α-Synuclein Gene and Relative Protein Content Are Affected by Ageing and Physical Exercise in Blood from Healthy Subjects

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    Epigenetic regulation may contribute to the beneficial effects of physical activity against age-related neurodegeneration. For example, epigenetic alterations of the gene encoding for α-synuclein (SNCA) have been widely explored in both brain and peripheral tissues of Parkinson’s disease samples. However, no data are currently available about the effects of physical exercise on SNCA epigenetic regulation in ageing healthy subjects. The present paper explored whether, in healthy individuals, age and physical activity are related to blood intron1-SNCA (SNCAI1) methylation, as well as further parameters linked to such epigenetic modification (total, oligomeric α-synuclein and DNA methyltransferase concentrations in the blood). Here, the SNCAI1 methylation status increased with ageing, and consistent with this result, low α-synuclein levels were found in the blood. The direct relationship between SNCAI1 methylation and α-synuclein levels was observed in samples characterized by blood α-synuclein concentrations of 76.3 ng/mg protein or lower (confidence interval (CI) = 95%). In this selected population, higher physical activity reduced the total and oligomeric α-synuclein levels. Taken together, our data shed light on ageing- and physical exercise-induced changes on the SNCA methylation status and protein levels of α-synuclein

    High Levels of β-Amyloid, Tau, and Phospho-Tau in Red Blood Cells as Biomarkers of Neuropathology in Senescence-Accelerated Mouse

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    Alzheimer’s Disease (AD) is the most common Neurodegenerative Disease (ND), primarily characterised by neuroinflammation, neuronal plaques of β-amyloid (Aβ), and neurofibrillary tangles of hyperphosphorylated tau. α-Synuclein (α-syn) and its heteroaggregates with Aβ and tau have been recently included among the neuropathological elements of NDs. These pathological traits are not restricted to the brain, but they reach peripheral fluids as well. In this sense, Red Blood Cells (RBCs) are emerging as a good model to investigate the biochemical alterations of aging and NDs. Herein, the levels of homo- and heteroaggregates of ND-related proteins were analysed at different stages of disease progression. In particular, a validated animal model of AD, the SAMP8 (Senescence-Accelerated Mouse-Prone) and its control strain SAMR1 (Senescence-Accelerated Mouse-Resistant) were used in parallel experiments. The levels of the aforementioned proteins and of the inflammatory marker interleukin-1β (IL-1β) were examined in both brain and RBCs of SAMP8 and SAMR1 at 6 and 8 months. Brain Aβ, tau, and phospho-tau (p-tau) were higher in SAMP8 mice than in control mice and increased with AD progression. Similar accumulation kinetics were found in RBCs, even if slower. By contrast, α-syn and its heterocomplexes (α-syn-Aβ and α-syn-tau) displayed different accumulation kinetics between brain tissue and RBCs. Both brain and peripheral IL-1β levels were higher in SAMP8 mice, but increased sooner in RBCs, suggesting that inflammation might initiate at a peripheral level before affecting the brain. In conclusion, these results confirm RBCs as a valuable model for monitoring neurodegeneration, suggesting peripheral Aβ, tau, and p-tau as potential early biomarkers of AD

    Targeted inhibition of Hedgehog-GLI signaling by novel acylguanidine derivatives inhibits melanoma cell growth by inducing replication stress and mitotic catastrophe

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    Aberrant activation of the Hedgehog (HH) signaling is a critical driver in tumorigenesis. The Smoothened (SMO) receptor is one of the major upstream transducers of the HH pathway and a target for the development of anticancer agents. The SMO inhibitor Vismodegib (GDC-0449/Erivedge) has been approved for treatment of basal cell carcinoma. However, the emergence of resistance during Vismodegib treatment and the occurrence of numerous side effects limit its use. Our group has recently discovered and developed novel and potent SMO inhibitors based on acylguanidine or acylthiourea scaffolds. Here, we show that the two acylguanidine analogs, compound (1) and its novel fluoride derivative (2), strongly reduce growth and self-renewal of melanoma cells, inhibiting the level of the HH signaling target GLI1 in a dose-dependent manner. Both compounds induce apoptosis and DNA damage through the ATR/CHK1 axis. Mechanistically, they prevent G2 to M cell cycle transition, and induce signs of mitotic aberrations ultimately leading to mitotic catastrophe. In a melanoma xenograft mouse model, systemic treatment with 1 produced a remarkable inhibition of tumor growth without body weight loss in mice. Our data highlight a novel route for cell death induction by SMO inhibitors and support their use in therapeutic approaches for melanoma and, possibly, other types of cancer with active HH signaling

    Soft Tissue Sarcoma Cancer Stem Cells: An Overview

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    Soft tissue sarcomas (STSs) are an uncommon group of solid tumors that can arise throughout the human lifespan. Despite their commonality as non-bony cancers that develop from mesenchymal cell precursors, they are heterogeneous in their genetic profiles, histology, and clinical features. This has made it difficult to identify a single target or therapy specific to STSs. And while there is no one cell of origin ascribed to all STSs, the cancer stem cell (CSC) principle—that a subpopulation of tumor cells possesses stem cell-like properties underlying tumor initiation, therapeutic resistance, disease recurrence, and metastasis—predicts that ultimately it should be possible to identify a feature common to all STSs that could function as a therapeutic Achilles' heel. Here we review the published evidence for CSCs in each of the most common STSs, then focus on the methods used to study CSCs, the developmental signaling pathways usurped by CSCs, and the epigenetic alterations critical for CSC identity that may be useful for further study of STS biology. We conclude with discussion of some challenges to the field and future directions

    α-Synuclein Heterocomplexes with β-Amyloid Are Increased in Red Blood Cells of Parkinson's Disease Patients and Correlate with Disease Severity

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    Neurodegenerative disorders (NDs) are characterized by abnormal accumulation/misfolding of specific proteins, primarily α-synuclein (α-syn), β-amyloid1-42(Aβ1-42) and tau, in both brain and peripheral tissues. In addition to oligomers, the role of the interactions of α-syn with Aβ or tau has gradually emerged. Nevertheless, despite intensive research, NDs have no accepted peripheral markers for biochemical diagnosis. In this respect, Red Blood Cells (RBCs) are emerging as a valid peripheral model for the study of aging-related pathologies. Herein, a small cohort (N= 28) of patients affected by Parkinson's disease (PD) and age-matched controls were enrolled to detect the content of α-syn (total and oligomeric), Aβ1-42and tau (total and phosphorylated) in RBCs. Moreover, the presence of α-syn association with tau and Aβ1-42was explored by co-immunoprecipitation/western blotting in the same cells, and quantitatively confirmed by immunoenzymatic assays. For the first time, PD patients were demonstrated to exhibit α-syn heterocomplexes with Aβ1-42and tau in peripheral tissues; interestingly, α-syn-Aβ1-42concentrations were increased in PD subjects with respect to healthy controls (HC), and directly correlated with disease severity and motor deficits. Moreover, total-α-syn levels were decreased in PD subjects and inversely related to their motor deficits. Finally, an increase of oligomeric-α-syn and phosphorylated-tau was observed in RBCs of the enrolled patients. The combination of three parameters (total-α-syn, phosphorylated-tau and α-syn-Aβ1-42concentrations) provided the best fitting predictive index for discriminating PD patients from controls. Nevertheless further investigations should be required, overall, these data suggest α-syn hetero-aggregates in RBCs as a putative tool for the diagnosis of PD
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