116 research outputs found

    Heparan sulfate proteoglycans: The sweet side of development turns sour in mucopolysaccharidoses

    Get PDF
    Abstract Heparan sulfate proteoglycans (HSPGs) are complex carbohydrate-modified proteins ubiquitously expressed on cell surfaces, extracellular matrix and basement membrane of mammalian tissues. Beside to serve as structural constituents, they regulate multiple cellular activities. A critical involvement of HSPGs in development has been established, and perturbations of HSPG-dependent pathways are associated with many human diseases. Recent evidence suggest a role of HSPGs in the pathogenesis of mucopolysaccharidoses (MPSs) where the accumulation of undigested HS results in the loss of cellular functions, tissue damage and organ dysfunctions accounting for clinical manifestations which include central nervous system (CNS) involvement, degenerative joint disease and reduced bone growth. Current therapies are not curative but only ameliorate the disease symptoms. Here, we highlight the link between HSPG functions in the development of CNS and musculoskeletal structures and the etiology of some MPS phenotypes, suggesting that HSPGs may represent potential targets for the therapy of such incurable diseases

    Competitive binding of extracellular accumulated heparan sulfate reduces lysosomal storage defects and triggers neuronal differentiation in a model of Mucopolysaccharidosis IIIB.

    Get PDF
    Mucopolysaccharidoses (MPSs) are a group of inherited lysosomal storage disorders associated with the deficiency of lysosomal enzymes involved in glycosaminoglycan (GAG) degradation. The resulting cellular accumulation of GAGs is responsible for widespread tissue and organ dysfunctions. The MPS III, caused by mutations in the genes responsible for the degradation of heparan sulfate (HS), includes four subtypes (A, B, C, and D) that present significant neurological manifestations such as progressive cognitive decline and behavioral disorders. The established treatments for the MPS III do not cure the disease but only ameliorate non-neurological clinical symptoms. We previously demonstrated that the natural variant of the hepatocyte growth factor NK1 reduces the lysosomal pathology and reactivates impaired growth factor signaling in fibroblasts from MPS IIIB patients. Here, we show that the recombinant NK1 is effective in rescuing the morphological and functional dysfunctions of lysosomes in a neuronal cellular model of the MPS IIIB. More importantly, NK1 treatment is able to stimulate neuronal differentiation of neuroblastoma SK-NBE cells stable silenced for the NAGLU gene causative of the MPS IIIB. These results provide the basis for the development of a novel approach to possibly correct the neurological phenotypes of the MPS IIIB as well as of other MPSs characterized by the accumulation of HS and progressive neurodegeneration

    Inhibiting the urokinase-type plasminogen activator receptor system recovers STZ-induced diabetic nephropathy.

    Get PDF
    The urokinase‐type plasminogen activator (uPA) receptor (uPAR) participates to the mechanisms causing renal damage in response to hyperglycaemia. The main function of uPAR in podocytes (as well as soluble uPAR ‐(s)uPAR‐ from circulation) is to regulate podocyte function through αvβ3 integrin/Rac‐1. We addressed the question of whether blocking the uPAR pathway with the small peptide UPARANT, which inhibits uPAR binding to the formyl peptide receptors (FPRs) can improve kidney lesions in a rat model of streptozotocin (STZ)‐induced diabetes. The concentration of systemically administered UPARANT was measured in the plasma, in kidney and liver extracts and UPARANT effects on dysregulated uPAR pathway, αvβ3 integrin/Rac‐1 activity, renal fibrosis and kidney morphology were determined. UPARANT was found to revert STZ‐induced up‐regulation of uPA levels and activity, while uPAR on podocytes and (s)uPAR were unaffected. In glomeruli, UPARANT inhibited FPR2 expression suggesting that the drug may act downstream uPAR, and recovered the increased activity of the αvβ3 integrin/Rac‐1 pathway indicating a major role of uPAR in regulating podocyte function. At the functional level, UPARANT was shown to ameliorate: (a) the standard renal parameters, (b) the vascular permeability, (c) the renal inflammation, (d) the renal fibrosis including dysregulated plasminogen‐plasmin system, extracellular matrix accumulation and glomerular fibrotic areas and (e) morphological alterations of the glomerulus including diseased filtration barrier. These results provide the first demonstration that blocking the uPAR pathway can improve diabetic kidney lesion in the STZ model, thus suggesting the uPA/uPAR system as a promising target for the development of novel uPAR‐targeting approaches

    d-Glucose Adsorption on the TiO2 Anatase (100) Surface: A Direct Comparison Between Cluster-Based and Periodic Approaches

    Get PDF
    Titanium dioxide (TiO2) has been extensively studied as a suitable material for a wide range of fields including catalysis and sensing. For example, TiO2-based nanoparticles are active in the catalytic conversion of glucose into value-added chemicals, while the good biocompatibility of titania allows for its application in innovative biosensing devices for glucose detection. A key process for efficient and selective biosensors and catalysts is the interaction and binding mode between the analyte and the sensor/catalyst surface. The relevant features regard both the molecular recognition event and its effects on the nanoparticle electronic structure. In this work, we address both these features by combining two first-principles methods based on periodic boundary conditions and cluster approaches (CAs). While the former allows for the investigation of extended materials and surfaces, CAs focus only on a local region of the surface but allow for using hybrid functionals with low computational cost, leading to a highly accurate description of electronic properties. Moreover, the CA is suitable for the study of reaction mechanisms and charged systems, which can be cumbersome with PBC. Here, a direct and detailed comparison of the two computational methodologies is applied for the investigation of d-glucose on the TiO2 (100) anatase surface. As an alternative to the commonly used PBC calculations, the CA is successfully exploited to characterize the formation of surface and subsurface oxygen vacancies and to determine their decisive role in d-glucose adsorption. The results of such direct comparison allow for the selection of an efficient, finite-size structural model that is suitable for future investigations of biosensor electrocatalytic processes and biomass conversion catalysis.</p

    Application of latent class analysis in assessing the awareness, attitude, practice and satisfaction of paediatricians on sleep disorder management in children in Italy.

    Get PDF
    AIM: To identify subgroups regarding paediatricians' awareness, attitude, practice and satisfaction about management of Sleep-Disordered Breathing (SDB) in Italy using Latent Class Analysis (LCA). METHODS: A cross-sectional study was conducted on a large sample of Italian paediatricians. Using a self-administered questionnaire, the study collected information on 420 Paediatric Hospital Paediatricians (PHPs) and 594 Family Care Paediatricians (FCPs). LCA was used to discover underlying response patterns, thus allowing identification of respondent groups with similar awareness, attitude, practice and satisfaction. A logistic regression model was used to investigate which independent variables influenced latent class membership. Analyses were performed using R 3.5.2 software. A p-value&lt;0.05 was considered statistically significant. RESULTS: Two classes were identified: Class 1 (n = 368, 36.29%) "Untrained and poorly satisfied" and Class 2 (n = 646, 63.71%) "Trained and satisfied." Involving paediatric pneumologists or otorhinolaryngologists in clinical practice was associated with an increased probability of Class 2 membership (OR = 5.88, 95%CI [2.94-13.19]; OR = 15.95, 95% CI [10.92-23.81] respectively). Examining more than 20 children with SDB during the last month decreased the probability of Class 2 membership (OR = 0.29, 95% CI [0.14-0.61]). FCPs showed a higher probability of Class 2 membership than PHPs (OR = 4.64, 95% CI [3.31-6.55]). CONCLUSIONS: These findings suggest that the LCA approach can provide important information on how education and training could be tailored for different subgroups of paediatricians. In Italy standardized educational interventions improving paediatricians' screening of SDB are needed in order to guarantee efficient management of children with SDB and reduce the burden of disease
    corecore